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Sample records for promoting rhizobacteria paenibacillus

  1. Loblolly pine seedling growth after inoculation with plant growth-promoting rhizobacteria and ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Estes, B.L.; Enebak, S.A.; Chappelka, A.H. [Auburn Univ., Auburn, AL (United States). School of Forestry and Wildlife Sciences

    2004-07-01

    The conifer tree species with the greatest economic importance in south eastern United States plantations is Loblolly pine. Plantations require intensive fertilization, pesticide application, and irrigation. In these cases growth-promoting rhizobacteria are useful in pest control. While it was once thought that ozone in the troposphere was limited to urban areas, it is now known that it is transported far from its place of origin. Ozone is known to impact plant growth negatively. There have been no previous studies on whether growth-promoting rhizobacteria can decrease the negative effects of ozone. In this study seedlings of Loblolly pine were inoculated with either Bacillus subtilis (Ehrenberg) Cohn or Paenibacillus macerans (Schardinger) Ash. These were exposed to controlled amounts of ozone for 8-12 weeks. All plants showed decreased biomass and increased foliar damage compared to plants that were not exposed to ozone. B. subtilis inoculated plants showed less foliar damage than un-inoculated ones and root dimensions were increased. The use of growth-promoting rhizobacteria is not ready for large-scale commercial application in forestry, but this demonstration of the possible beneficial effects on ozone exposure warrants further investigation. 44 refs., 3 tabs., 2 figs.

  2. Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective

    Directory of Open Access Journals (Sweden)

    Munees Ahemad

    2014-01-01

    Full Text Available Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root surface and are directly or indirectly involved in promoting plant growth and development via production and secretion of various regulatory chemicals in the vicinity of rhizosphere. Generally, plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in resource acquisition (nitrogen, phosphorus and essential minerals or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. Various studies have documented the increased health and productivity of different plant species by the application of plant growth promoting rhizobacteria under both normal and stressed conditions. The plant-beneficial rhizobacteria may decrease the global dependence on hazardous agricultural chemicals which destabilize the agro-ecosystems. This review accentuates the perception of the rhizosphere and plant growth promoting rhizobacteria under the current perspectives. Further, explicit outlooks on the different mechanisms of rhizobacteria mediated plant growth promotion have been described in detail with the recent development and research. Finally, the latest paradigms of applicability of these beneficial rhizobacteria in different agro-ecosystems have been presented comprehensively under both normal and stress conditions to highlight the recent trends with the aim to develop future insights.

  3. deaminase from plant growth promoting rhizobacteria in Striga

    African Journals Online (AJOL)

    Experiments were conducted in pots to determine the growth effect of different rhizobacteria on maize under Striga hermonthica infestation. Three bacteria were selected based on their plant growth promoting effects. Whole bacterial cells of the rhizobacteria were used to amplify 1-amino-cyclopropane-1-carboxylic acid ...

  4. Screening of Plant Growth-Promoting Rhizobacteria from Maize ...

    African Journals Online (AJOL)

    Screening of Plant Growth-Promoting Rhizobacteria from Maize ( Zea Mays ) and Wheat ( Triticum Aestivum ) ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN ... African Journal of Food, Agriculture, Nutrition and Development.

  5. Plant growth-promoting rhizobacteria (PGPR: their potential as antagonists and biocontrol agents

    Directory of Open Access Journals (Sweden)

    Anelise Beneduzi

    2012-01-01

    Full Text Available Bacteria that colonize plant roots and promote plant growth are referred to as plant growth-promoting rhizobacteria (PGPR. PGPR are highly diverse and in this review we focus on rhizobacteria as biocontrol agents. Their effects can occur via local antagonism to soil-borne pathogens or by induction of systemic resistance against pathogens throughout the entire plant. Several substances produced by antagonistic rhizobacteria have been related to pathogen control and indirect promotion of growth in many plants, such as siderophores and antibiotics. Induced systemic resistance (ISR in plants resembles pathogen-induced systemic acquired resistance (SAR under conditions where the inducing bacteria and the challenging pathogen remain spatially separated. Both types of induced resistance render uninfected plant parts more resistant to pathogens in several plant species. Rhizobacteria induce resistance through the salicylic acid-dependent SAR pathway, or require jasmonic acid and ethylene perception from the plant for ISR. Rhizobacteria belonging to the genera Pseudomonas and Bacillus are well known for their antagonistic effects and their ability to trigger ISR. Resistance-inducing and antagonistic rhizobacteria might be useful in formulating new inoculants with combinations of different mechanisms of action, leading to a more efficient use for biocontrol strategies to improve cropping systems.

  6. Potential effects of plant growth promoting rhizobacteria ...

    African Journals Online (AJOL)

    Damping off caused by Sclerotium rolfsii on cowpea results in yield losses with serious socioeconomic implication. Induction of defense responses by plant growth promoting rhizobacteria (PGPR) is largely associated with the production of defense enzyme phenyl ammonia lyase (PAL) and oxidative enzymes like ...

  7. Purple corn-associated rhizobacteria with potential for plant growth promotion.

    Science.gov (United States)

    Castellano-Hinojosa, A; Pérez-Tapia, V; Bedmar, E J; Santillana, N

    2018-05-01

    Purple corn (Zea mays var. purple amylaceum) is a native variety of the Peruvian Andes, cultivated at 3000 m since the pre-Inca times without N fertilization. We aimed to isolate and identify native plant growth-promoting rhizobacteria (PGPR) for future microbial-based inoculants. Eighteen strains were isolated from the rhizosphere of purple corn plants grown without N fertilization in Ayacucho (Peru). The 16S rRNA gene clustered the 18 strains into nine groups that contained species of Bacillus, Stenotrophomonas, Achromobacter, Paenibacillus, Pseudomonas and Lysinibacillus. A representative strain from each group was selected and assayed for N 2 fixation, phosphate solubilization, indole acetic and siderophore production, 1-aminocyclopropane-1-carboxylic acid deaminase activity and biocontrol abilities. Inoculation of purple corn plants with single and combined strains selected after a principal component analysis caused significant increases in root and shoot dry weight, total C and N contents of the plants. PGPRs can support growth and crop production of purple corn in the Peruvian Andes and constitute the base for microbial-based inoculants. This study enlarges our knowledge on plant-microbial interactions in high altitude mountains and provides new applications for PGPR inoculation in purple amylaceum corn, which is part of the staple diet for the native Quechua communities. © 2018 The Society for Applied Microbiology.

  8. Effects of plant growth promoting rhizobacteria (PGPR on rooting and root growth of kiwifruit (Actinidia deliciosa stem cuttings

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    YASAR ERTURK

    2010-01-01

    Full Text Available The effects of plant growth promoting rhizobacteria (PGPR on the rooting and root growth of semi-hardwood and hardwood kiwifruit stem cuttings were investigated. The PGPR used were Bacillus RC23, Paenibacillus polymyxa RC05, Bacillus subtilis OSU142, Bacillus RC03, Comamonas acidovorans RC41, Bacillus megaterium RC01 and Bacillus simplex RC19. All the bacteria showed indole-3-acetic acid (IAA producing capacity. Among the PGPR used, the highest rooting ratios were obtained at 47.50% for semi-hardwood stem cuttings from Bacillus RC03 and Bacillus simplex RC19 treatments and 42.50% for hardwood stem cuttings from Bacillus RC03. As well, Comamonas acidovorans RC41 inoculations indicated higher value than control treatments. The results suggest that these PGPR can be used in organic nursery material production and point to the feasibility of synthetic auxin (IBA replacement by organic management based on PGPR.

  9. Diversity and Plant Growth Promoting Properties of Rhizobacteria ...

    African Journals Online (AJOL)

    characteristics of plant growth promoting rhizobacteria (PGPR) and hence selected for further study. The sixty ... tolerance to a wide range of pH by most of the isolates. The 66 isolates ... chemicals and change in traditional cultivation practices ...

  10. Isolation and Characterization of Diazotrophic Rhizobacteria of Oil Palm Roots

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    Azlin, C. O.

    2005-01-01

    Full Text Available Beneficial rhizobacteria were isolated from two different compartments of oil palm roots; the rhizosphere or rhizoplane and the inner root tissues. The root samples were collected from oil palm plantation at Felda Lepar 9, Temerloh Pahang (Block 17, Square 6 (soil pH 4.30; 10:25 0.01M CaCl2. Identification of the isolates was conducted by classical biochemical and physiological tests. Acetylene Reduction Assay (ARA test was also conducted to quantify the ability of the isolates to fix atmospheric N2. Twenty-nine strains of rhizobacteria were isolated from root samples and were maintained aerobically on N-free solid media. Seven of the isolates were identified as Gram negative while the rest were Gram positive. The isolates were successfully identified as Paenibacillus durus (formerly P. azotofixans, Paenibacillus polymyxa, Azospirillum lipoferum, Herbaspirillum seropedicae and Acetobacter diazotrophicus. The N2 fixation capacities of the isolates ranged from 7.0 x 10-12 to 1.0 x 10-8 mol C2H4/cfu/hour.

  11. Plant growth promoting rhizobacteria: Beneficial effects for healthy ...

    African Journals Online (AJOL)

    It is unanimously admitted that the chemical fertilizers and pesticides used in modern agriculture create a real environmental and public health problems. One of the promising solutions to substitute these agrochemicals products is the use of bio-resources, including plant growth promoting rhizobacteria (PGPR). The PGPR ...

  12. Efficiency of plant growth-promoting rhizobacteria (PGPR) for the ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-06

    Apr 6, 2009 ... effects of PGPR isolates on the growth of rice, a pot culture experiment was conducted. Prior to seeds ... undertaken to screen the PGPR strains that are ..... promoting rhizobacteria on bell pepper production and green peach.

  13. Effects on Glomus mosseae Root Colonization by Paenibacillus polymyxa and Paenibacillus brasilensis Strains as Related to Soil P-Availability in Winter Wheat

    International Nuclear Information System (INIS)

    Arthurson, V; Granhall, U; Derlund, L; Hjort, K; Muleta, D

    2011-01-01

    Greenhouse experiments were conducted to assess the effects of inoculating winter wheat (Triticum aestivum) with plant growth promoting rhizobacteria (PGPR) of the genus Paenibacillus under phosphate P-limited soil conditions in the presence or absence of the arbuscular mycorrhizal fungus (AMF) Glomus mosseae. Four P. polymyxa strains and one P. brasilensis strain were compared at two cell concentrations (10 6 and 10 8 cells g -1 seeds) of inoculation, and surface sterilized AMF spores were added to pots. Mycorrhizal root colonization, plant growth, and plant uptake of phosphorus were analyzed. Bacterial phosphate solubilization was examined separately in vitro. Most P. polymyxa strains, isolated from wheat, had dramatic effects per se on root growth and root P-content. No treatment gave significant effect on shoot growth. AMF root colonization levels and total plant uptake of P were much stimulated by the addition of most P. polymyxa strains. The AM fungus alone and the P. brasilensis, alone or in combination with the fungus, did not affect total plant P-levels. Our results indicate that practical application of inoculation with plant host-specific rhizobacteria (i.e., P. polymyxa) could positively influence uptake of phosphorus in P-

  14. Effects of inoculation of plant growth-promoting rhizobacteria on metal uptake by Brassica juncea

    International Nuclear Information System (INIS)

    Wu, S.C.; Cheung, K.C.; Luo, Y.M.; Wong, M.H.

    2006-01-01

    A greenhouse study was carried out with Brassica juncea to critically evaluate effects of bacterial inoculation on the uptake of heavy metals from Pb-Zn mine tailings by plants. Application of plant growth-promoting rhizobacteria, including nitrogen-fixing bacteria and phosphate and potassium solubilizers, might play an important role in the further development of phytoremediation techniques. The presence of these beneficial bacteria stimulated plant growth and protected the plant from metal toxicity. Inoculation with rhizobacteria had little influence on the metal concentrations in plant tissues, but produced a much larger above-ground biomass and altered metal bioavailability in the soil. As a consequence, higher efficiency of phytoextraction was obtained compared with control treatments. - Rhizobacteria promoted growth above normal biomass, but did not influence plant metal concentrations

  15. Effects of inoculation of plant growth-promoting rhizobacteria on metal uptake by Brassica juncea

    Energy Technology Data Exchange (ETDEWEB)

    Wu, S.C. [Department of Biology and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Joint Open Laboratory on Soil and Environment between HKBU and ISSCAS (China); Cheung, K.C. [Department of Biology and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Joint Open Laboratory on Soil and Environment between HKBU and ISSCAS (China); Luo, Y.M. [Institute of Soil Science, Chinese Academy of Sciences, Nanjing (China); Joint Open Laboratory on Soil and Environment between HKBU and ISSCAS (China); Wong, M.H. [Department of Biology and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China) and Joint Open Laboratory on Soil and Environment between HKBU and ISSCAS (China)]. E-mail: mhwong@hkbu.edu.hk

    2006-03-15

    A greenhouse study was carried out with Brassica juncea to critically evaluate effects of bacterial inoculation on the uptake of heavy metals from Pb-Zn mine tailings by plants. Application of plant growth-promoting rhizobacteria, including nitrogen-fixing bacteria and phosphate and potassium solubilizers, might play an important role in the further development of phytoremediation techniques. The presence of these beneficial bacteria stimulated plant growth and protected the plant from metal toxicity. Inoculation with rhizobacteria had little influence on the metal concentrations in plant tissues, but produced a much larger above-ground biomass and altered metal bioavailability in the soil. As a consequence, higher efficiency of phytoextraction was obtained compared with control treatments. - Rhizobacteria promoted growth above normal biomass, but did not influence plant metal concentrations.

  16. Effect of plant growth promoting rhizobacteria on root morphology of ...

    African Journals Online (AJOL)

    Jane

    2011-10-03

    Oct 3, 2011 ... Plant growth promoting rhizobacteria improve the plant growth by a variety of ways like ... preparing textile dye in the Far East, Central and. Northern Asia and ... The experiment was carried out in complete randomized design.

  17. Efficiency of plant growth-promoting rhizobacteria (PGPR) for the ...

    African Journals Online (AJOL)

    Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. The use of PGPR is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides, and supplements. Here, we have isolated and ...

  18. Effect of plant-growth-promoting rhizobacteria inoculation on plant ...

    African Journals Online (AJOL)

    A field experiment was conducted in a wet season (Kharif) to study the effects of plant growth-promoting rhizobacteria(PGPR) inoculation on agronomic traits and productivity of Basmati rice (cv. 'Pusa Basmati 1401') in a randomized block with twelve treatments. We evaluated one bacterial (Providencia sp. PW5) and one ...

  19. Isolation, Characterization, Screening, Formulation and Evaluation of Plant Growth Promoting Rhizobacteria

    Directory of Open Access Journals (Sweden)

    Puja Kumari

    2017-10-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR are bioresources which may be viewed as a novel and potential tool for providing substantial benefits to the agriculture. Soil is the dynamic living matrix and the major source of food security providing various resources of plant growth and maintaining life processes. PGPR are originally defined as root- colonizing bacteria that cause either plant growth promotion or biological control of plant diseases. Chemical fertilizers are used for killing pathogens, increase crop yield but long term use of chemical fertilizers lead to adverse effect to the soil profile and is the reason for decrease in soil productivity, on the other hand PGPR promote plant growth directly by either facilitating resource acquisition (nitrogen, phosphorus and essential minerals or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. PGPR is the indispensable part of rhizosphere biota that when grown in association with the host plants can stimulate the growth of the host. PGPR seemed as successful rhizobacteria in getting established in soil ecosystem due to their high adaptability in a wide variety of environments, faster growth rate and biochemical versatility to metabolize a wide range of natural and xenobiotic compounds. Isolated PGPRs from selective crop rizosphere soil were used for further growth promotion and biocontrol studies in the green house and field. Different studies have been carrying out to develop some new bioformulations and evaluate their efficacy in promoting crop seedlings growth characteristics. Field trials were performed to evaluate selective crops with formulations of several plants PGPR in a production system. The present review highlights the Plant growth promoting rhizobacteria as an alternative of chemical fertilizer for sustainable, environment friendly agriculture.

  20. Metabolic and biofungicidal properties of maize rhizobacteria for ...

    African Journals Online (AJOL)

    Plant growth promoting rhizobacteria (PGPR) are known to influence plant growing both by direct and/or indirect mechanisms. This study aimed to establish PGPR profile of 15 bacteria isolated from maize (Zea mays L.) rhizosphere in Benin. These rhizobacteria were screened in vitro for the plant growth promoting traits like ...

  1. In vitro antagonistic activity, plant growth promoting traits and phylogenetic affiliation of rhizobacteria associated with wild plants grown in arid soil

    OpenAIRE

    El-Sayed, Wael S.; Akhkha, Abdellah; El-Naggar, Moustafa Y.; Elbadry, Medhat

    2014-01-01

    The role of plant growth-promoting rhizobacteria (PGPR) in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with 11 wild plant species from the arid soil of Alm...

  2. Growth promoting characteristics of rhizobacteria and AM Fungi for biomass amelioration of Zea mays

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    Kumar Manoj

    2015-01-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR and mycorrhiza were evaluated on the growth (biomass and yield of Zea mays. In the present study, selective rhizospheric PGPR (Azotobacter chroococcum, Pseudomonas aeruginosa, Azospirillum brasilense and Streptomyces sp. and a combination of six strains of arbuscular mycorrhizal fungi (AMF (Acaulospora morrowae, Gigaspora margarita, Glomus constrictum, Glomus mossae, Glomus aggregatum and Scutellospora calospora were isolated and identified with standard methods and 16S rRNA sequence analysis. PGPR and AMF were checked for their growth-promoting behavior under specific treatment conditions. The 30-48-day-old treated plants in all combinations showed a significantly higher mass value. The average dry weight from the shoot was in a range from 41-52% as compared to the control. This increase also translated into a higher mass value of the roots. Overall, an 82% growth rate was observed in terms of height as the consequence of biomass production, specifically in the case of AMF + rhizobacteria combination. We report an efficient, sustainable and cost-effective biofertilizer for enhanced biomass of Z. mays, one of the staple food crops worldwide.

  3. Characterization of Potential Plant Growth Promoting Rhizobacteria Isolated from Maize (Zea mays L. in Central and Northern Benin (West Africa

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    Nadège A. Agbodjato

    2015-01-01

    Full Text Available Our study aims to characterize Plant Growth Promoting Rhizobacteria (PGPR isolated from maize roots in five agroecological zones of central and northern Benin. Sixty samples were collected at the rate of four samples per village and three villages per agroecological zone. Rhizobacteria strains were isolated from these samples and biochemically characterized. These strains were analyzed for some of their PGPR traits like ammonia production and hydrogen cyanide following conventional methods. Microbiological investigation of these samples has shown that maize rhizospheres in central and northern Benin contain a high diversity of microorganisms. A total of nine species of maize Plant Growth Promoting Rhizobacteria were identified. Those PGPR include five Bacillus species (B. polymyxa, B. pantothenticus, B. anthracis, B. thuringiensis, and B. circulans, three Pseudomonas species (P. cichorii, P. putida, and P. syringae, and Serratia marcescens. The microbial diversity does not depend on the soil types. The microbial density, generally high, varies according to both soil types and agroecological zones. All Serratia strains (100% have produced ammonia, whereas 80% of Bacillus and 77.77% of Pseudomonas produced this metabolite. The hydrogen cyanide was produced by all isolates (100% independent of their genus. These results suggest the possibility to use these rhizobacteria as biological fertilizers to increase maize production.

  4. Plant Growth Promoting Rhizobacteria in Amelioration of Salinity Stress: A Systems Biology Perspective

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    Gayathri Ilangumaran

    2017-10-01

    Full Text Available Salinity affects plant growth and is a major abiotic stress that limits crop productivity. It is well-understood that environmental adaptations and genetic traits regulate salinity tolerance in plants, but imparting the knowledge gained towards crop improvement remain arduous. Harnessing the potential of beneficial microorganisms present in the rhizosphere is an alternative strategy for improving plant stress tolerance. This review intends to elucidate the understanding of salinity tolerance mechanisms attributed by plant growth promoting rhizobacteria (PGPR. Recent advances in molecular studies have yielded insights into the signaling networks of plant–microbe interactions that contribute to salt tolerance. The beneficial effects of PGPR involve boosting key physiological processes, including water and nutrient uptake, photosynthesis, and source-sink relationships that promote growth and development. The regulation of osmotic balance and ion homeostasis by PGPR are conducted through modulation of phytohormone status, gene expression, protein function, and metabolite synthesis in plants. As a result, improved antioxidant activity, osmolyte accumulation, proton transport machinery, salt compartmentalization, and nutrient status reduce osmotic stress and ion toxicity. Furthermore, in addition to indole-3-acetic acid and 1-aminocyclopropane-1-carboxylic acid deaminase biosynthesis, other extracellular secretions of the rhizobacteria function as signaling molecules and elicit stress responsive pathways. Application of PGPR inoculants is a promising measure to combat salinity in agricultural fields, thereby increasing global food production.

  5. Expression of the N2 fixation gene operon of Paenibacillus sp. WLY78 under the control of the T7 promoter in Escherichia coli BL21.

    Science.gov (United States)

    Zhang, Lihong; Liu, Xiaomeng; Li, Xinxin; Chen, Sanfeng

    2015-10-01

    To investigate the transcription and translation and nitrogenase activity of the nine N2-fixing-gene (nif) operon (nifBHDKENXhesAnifX) of Paenibacillus sp. WLY78 under the control of the T7 promoter in Escherichia coli BL21 under different conditions. The Paenibacillus nif operon under the control of the T7 promoter is significantly transcribed and effectively translated in E. coli BL21 when grown in medium containing organic N compounds (yeast extract and Tryptone) or NH4+ by using RT-PCR and Western blot analysis. Transcription and translation of foreign nif genes in E. coli are not inhibited by environmental organic or inorganic N compounds or O2. However, contrary to transcription and translation, nitrogenase activity is 4% lower in the recombinant E. coli 78-32 compared to the native Paenibacillus sp. WLY78. The Paenibacillus nif operon under the control of T7 promoter enables E. coli BL21 to synthesize active nitrogenase. This study shows how the nif gene operon can be transferred to non-N2-fixing bacteria or to eukaryotic organelles.

  6. Isolation of plant growth promoting rhizobacteria of guava plants (Psidium guajava

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    Blanca Estela Gómez Luna

    2012-09-01

    Full Text Available Guava production for 2008 in the state of Guanajuato was 177 ha in area planted and the same number of area harvested, production in 1,130.80 Ton. In traditional farming practices have made excessive use of mineral fertilizers, which, if it is true, ensure a good production are expensive and come to cause imbalances in agroecosystems by contamination of soil, water, and food. In this work we evaluated the effect of Bacillus subtilis strains as plant growth promoter rhizobacteria in guava plants under greenhouse conditions. We used three strains were inoculated potted plant with guava. We measured the height, number of branches and leaves. Guava orchards of 2 then display of soil were taken for the isolation andcharacterization of rhizobacteria. Selective medium was used with 1 - carboxylic acid, -1 - aminocyclopropane and selecting bacteria with ACC desaminase activity. For the isolates were determined antibiotic resistance, confrontation with fungal pathogens, plant growth tests in vitro and BIOLOG metabolic profiles. We found 30 isolates with ACC activities, 7 have the effect of biological control and 5 had effect on root development in vitro. The use of growth promotingrhizobacteria are an excellent alternative for improving the production of guavas, growing very little is known of themicroflora associated with the rhizosphere and the ecological role they have in the ground.

  7. Assessing the efficacy of co-inoculation of wheat seedlings with the associative bacteria Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245.

    Science.gov (United States)

    Yegorenkova, Irina V; Tregubova, Kristina V; Burygin, Gennady L; Matora, Larisa Y; Ignatov, Vladimir V

    2016-03-01

    Co-inoculation of associative bacteria, which have high nitrogen-fixing activity, tolerance for environmental conditions, and the ability to compete with the natural microflora, is used widely to enhance the growth and yields of agricultural plants. We evaluated the ability of 2 co-inoculated plant-growth-promoting rhizobacteria, Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245, to colonize roots of wheat (Triticum aestivum L. 'Saratovskaya 29') seedlings, and we assessed the morphometric parameters of wheat early in its development. Analysis by ELISA with polyclonal antibodies raised against the exopolysaccharide of P. polymyxa 1465 and the lipopolysaccharide of A. brasilense Sp245 demonstrated that the root-colonizing activity of A. brasilense was higher when the bacterium was co-inoculated with P. polymyxa than when it was inoculated singly. Immunofluorescence microscopy with Alexa Fluor 532-labeled antibodies revealed sites of attachment of co-inoculated P. polymyxa and A. brasilense and showed that the 2 bacteria colonized similar regions of the roots. Co-inoculation exerted a negative effect on wheat seedling development, inhibiting root length by 17.6%, total root weight by 11%, and total shoot weight by 12%. Under certain conditions, dual inoculation of wheat may prove ineffective, apparently owing to the competition between the rhizobacteria for colonization sites on the plant roots. The findings from this study may aid in developing techniques for mixed bacterial inoculation of cultivated plants.

  8. Assessment of Culturable Tea Rhizobacteria Isolated from Tea Estates of Assam, India for Growth Promotion in Commercial Tea Cultivars

    Science.gov (United States)

    Dutta, Jintu; Handique, Pratap J.; Thakur, Debajit

    2015-01-01

    In the present study, 217 rhizobacterial isolates were obtained from six different tea estates of Assam, India and subjected to preliminary in vitro plant growth promotion (PGP) screening for indole acetic acid (IAA) production, phosphate solubilization, siderophore production and ammonia production. Fifty isolates showed all the PGP traits and five isolates did not exhibit any PGP traits. These 50 potential isolates were further analyzed for quantitative estimation of the PGP traits along with the aminocyclopropane-1-carboxylate (ACC) deaminase, protease and cellulose production. After several rounds of screening, four rhizobacteria were selected based on their maximum ability to produce in vitro PGP traits and their partial 16S rRNA gene sequence analysis revealed that they belong to Enterobacter lignolyticus strain TG1, Burkholderia sp. stain TT6, Bacillus pseudomycoides strain SN29 and Pseudomonas aeruginosa strain KH45. To evaluate the efficacy of these four rhizobacteria as plant growth promoters, three different commercially important tea clones TV1, TV19, and TV20 plants were inoculated with these rhizobacteria in greenhouse condition and compared to the uninoculated control plants. Though, all the rhizobacterial treatments showed an increase in plant growth compared to control but the multivariate PCA analysis confirmed more growth promotion by TG1 and SN29 strains than the other treatments in all three clones. To validate this result, the fold change analysis was performed and it revealed that the tea clone TV19 plants inoculated with the E. lignolyticus strain TG1 showed maximum root biomass production with an increase in 4.3-fold, shoot biomass with increase in 3.1-fold, root length by 2.2-fold and shoot length by 1.6-fold. Moreover, two way ANOVA analysis also revealed that rhizobacterial treatment in different tea clones showed the significant increase (P biofertilizer for growth promotion of tea crops. PMID:26617590

  9. Growth Response and Tolerance to Heavy Metals of two Swamp Species inoculated with a Plant Growth-Promoting Rhizobacteria

    International Nuclear Information System (INIS)

    Rodriguez-Dorantes, A.; Labra-Cardon, D.; Guerrero-Zuniga, A.; Montes-Villafan, S.

    2009-01-01

    Due to the sensitivity and the sequestration ability of the microbial communities to heavy metals, microbes have been used for bioremediation. Recently the application of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of this kind of contaminants has been done. This study evaluated the growth response and the tolerance to heavy metals of two swamp species. (Author)

  10. Impacts of Plant Growth-Promoting Rhizobacteria-based Biostimulants on Wheat Growth under Greenhouse and Field Conditions

    OpenAIRE

    Nguyen, Minh; Ongena, Marc; Colinet, Gilles; Vandenbol, Micheline; Spaepen, Stijn; Bodson, Bernard; Jijakli, Haissam; du Jardin, Patrick; Delaplace, Pierre

    2015-01-01

    Plant Growth-Promoting Rhizobacteria (PGPR) are one of the main biostimulant classes due to their capacity of stimulating root growth and enhancing soil mineral availability, hence increasing nutrient use efficiency in crops. The aim of this study is to screen commercially PGPR-containing products to enhance wheat growth and yield in combination with an optimized nitrogen (N) fertilizer application scheme. This could lead to a significant reduction of N fertilizer application without affectin...

  11. Portraying mechanics of plant growth promoting rhizobacteria (PGPR: A review

    Directory of Open Access Journals (Sweden)

    Dweipayan Goswami

    2016-12-01

    Full Text Available Population growth and increase in food requirement is the global problem. It is inevitable to introduce new practices that help to increase agricultural productivity. Use of plant growth promoting rhizobacteria (PGPR has shown potentials to be a promising technique in the practice of sustainable agriculture. A group of natural soil microbial flora acquire dwelling in the rhizosphere and on the surface of the plant roots which impose beneficial effect on the overall well-being of the plant are categorized as PGPR. Researchers are actively involved in understanding plant growth promoting mechanics employed by PGPR. Broadly, these are divided into direct and indirect mechanics. Any mechanism that directly enhances plant growth either by providing nutrients or by producing growth regulators are portrayed as direct mechanics. Whereas, any mechanisms that protects plant from acquiring infections (biotic stress or helps plant to grow healthily under environmental stresses (abiotic stress are considered indirect mechanics. This review is focused to describe cogent mechanics employed by PGPR that assists plant to sustain healthy growth. Also, we emphasized on the PGPR-based products which have been commercially developed exploiting these mechanics of PGPR.

  12. Biocontrol of Fusarium Crown and Root Rot and Promotion of Growth of Tomato by Paenibacillus Strains Isolated from Soil

    Science.gov (United States)

    Xu, Sheng Jun

    2014-01-01

    In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant. PMID:25071385

  13. EFFICIENCY OF PLANT GROWTH PROMOTING RHIZOBACTERIA (PGPR IN SUGARCANE

    Directory of Open Access Journals (Sweden)

    Antonio Morgado González

    2015-10-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR are an alternative for promoting sugarcane (Saccharum spp. development. Growth promotion was evaluated in sugarcane vitroplants inoculated separately with twenty-four strains of seven different bacterial species. Total indole synthesis and phosphate solubilization activity were determined in each strain. The experimental unit was one 5 L pot filled with a sterile mixture of farm soil-agrolite and one plant. The experimental design was completely random. Inoculation consisted of 1.0 mL of bacterial suspension (1 × 107 CFU. Plant height, stem diameter, number of shoots, leaf area and dry matter of shoot and root were determined every two weeks. The Ochrobactrum anthropi strains N208 and IMP311 and Pseudomonas luteola IMPCA244 had the highest production of total indoles (116.69, 115.70 and 117.34 µg mL-1, respectively. The Stenotrophomonas maltophilia strains CA158 and 79 exhibited the highest values of phosphate solubilization (222.43 and 216.38 µg mL-1, respectively. In general, plant height increased 27.75%, stem diameter 30.75%, number of tillers 38.5%, leaf area 49%, aerial dry matter 59.75% and root dry matter 59.5%. P. luteola, P. f luorescens, O. anthropi and S. maltophilia exhibited the highest values of the leaf area index, net assimilation, and relative and absolute growth rates. P. luteola IMPCA244, O. anthropi IMP311, Aeromonas salmonicida N264, Burkholderia cepacia N172, P. f luorescens N50 and S. maltophilia 79 promoted the highest values in different response variables throughout the study. Before using these strains as sugarcane biofertilizer, additional studies are required.

  14. Halotolerant rhizobacteria promote growth and enhance salinity tolerance in peanut

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    Sandeep Sharma

    2016-10-01

    Full Text Available Use of Plant growth promoting rhizobacteria (PGPR is a promising strategy to improve the crop production under optimal or sub-optimal conditions. In the present study, five diazotrophic salt tolerant bacteria were isolated from the roots of a halophyte, Arthrocnemum indicum. The isolates were partially characterized in vitro for plant growth promoting traits and evaluated for their potential to promote growth and enhanced salt tolerance in peanut. The 16S rRNA gene sequence homology indicated that these bacterial isolates belong to the genera, Klebisiella, Pseudomonas, Agrobacterium and Ochrobactrum. All isolates were nifH positive and able to produce indole -3-acetic acid (ranging from 11.5 to 19.1 µg ml-1. The isolates showed phosphate solubilisation activity (ranging from 1.4 to 55.6 µg phosphate /mg dry weight, 1-aminocyclopropane-1-carboxylate deaminase activity (0.1 to 0.31 µmol α-kB/µg protein/h and were capable of reducing acetylene in acetylene reduction assay (ranging from 0.95 to 1.8 µmol C2H4 mg protein/h. These isolates successfully colonized the peanut roots and were capable of promoting the growth under non-stress condition. A significant increase in total nitrogen (N content (up to 76% was observed over the non-inoculated control. All isolates showed tolerance to NaCl ranging from 4-8% in nutrient broth medium. Under salt stress, inoculated peanut seedlings maintained ion homeostasis, accumulated less reactive oxygen species (ROS and showed enhanced growth compared to non-inoculated seedlings. Overall, the present study has characterized several potential bacterial strains that showed an enhanced growth promotion effect on peanut under control as well as saline conditions. The results show the possibility to reduce chemical fertilizer inputs and may promote the use of bio-inoculants.

  15. The effectiveness of various Rhizobacteria carriers to improve the shelf life and the stability of Rhizobacteria as Bioherbicide

    Science.gov (United States)

    Rakian, T. C.; Karimuna, L.; Taufik, M.; Sutariati, G. A. K.; Muhidin; Fermin, U.

    2018-02-01

    Deleterius Rhizobacteria (DRB) has a potential to control of weed and act as a bioherbicide. Developing a method to weed control that environmentally sound friendly has been increasingly studied. Rhizobacteria can form colonies on weed rooting and synthesize the secondary metabolite compounds. The effectiveness of rhizobacteria as bioherbicide is determined by its survival to be stored for a long time. The objective of this study is to obtain the type of carrier which effectively maintains the life and stability of DRB. Therefore it is necessary to do in vivo and in-vitro research. This study consists of two stages of testing the effectiveness of the carrier in increasing the shelf life of rhizobacteria and testing the effectiveness stability as a bioherbicide on Ageratum conyzoides weed after storage for 20 weeks. Research was conducted in Agronomy Lab, Agriculture Faculty, Halu Oleo University Kendari, Since August to December 2016. Research found that the talc powder and chaff charcoal powder were effective as a carrier of rhizobacteria and able to maintain the viability of rhizobacteria Bacillus lentus A05 and Pseudomonas aeruginosa A08 for five months and also able to maintain the stability of rhizobacteria as bioherbicide.

  16. Screen, Identification and Analysis on the Growth-Promoting Ability for the Rice Growth-Promoting Rhizobacteria

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    LIU Ze-ping

    2018-02-01

    Full Text Available Plant growth-promoting rhizobacteria(PGPRcan secrete the growth hormone and promote soil nutrient cycling, thus, is an important germplasm resource of bio -fertilizer. In this study, the PGPR was isolated from the rice rhizosphere. According to 16S rDNA sequences, 10 strains were identifed, including 4 organic phosphorus bacteria (Bacillus pumilus LZP02, Bacillus aryabhattai LZP08, Staphylococcus epidermidis LZP10, Bacillus ginsengisoli LZP05, 3 inorganic phosphorus bacteria(Bacillus megaterium LZP03, Bacillus oryzaecorticis LZP04, Bacillus ginsengisoli LZP07and 3 potassium bacteria(Bacillus aryabhattai LZP01, Bacillus subtilis LZP06, Bacillus licheniformis LZP09. The results from nutrient conversion analysis showed that Bacillus aryabhattai LZP01 and Bacillus subtilis LZP06 performed better on the potassium releasing ability. Bacillus pumilus LZP02 and Bacillus huizhouensis LZP05 performed better on the function of organic phosphorus. Bacillus megaterium LZP03 and Bacillus ginsengisoli LZP07 performed better on the function of inorganic phosphorus. Further, the hormone secretion capacity was measured for these 6 strains. The results showed that all 6 strains could produce auxin and gibberellin, and had the ability to synthesize iron carrier. Moreover, the results showed that Bacillus megaterium LZP03, Bacillus huizhouensis LZP05 and Bacillus subtilis LZP06 had stronger ability to promote the nutrient conversion and hormone secretion. Systematically, we believe that these three strains have great potential application on microbial fertilizer.

  17. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    Science.gov (United States)

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  18. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana

    Directory of Open Access Journals (Sweden)

    Yong-Soon Park

    2015-09-01

    Full Text Available Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  19. Colonization of Plant Growth Promoting Rhizobacteria (PGPR) on Two Different Root Systems

    International Nuclear Information System (INIS)

    Chaudhry, M. Z.; Naz, A. U.; Nawaz, A.; Nawaz, A.; Mukhtar, H.

    2016-01-01

    Phytohormones producing bacteria enhance the plants growth by positively affecting growth of the root. Plant growth promoting bacteria (PGPR) must colonize the plant roots to contribute to the plant's endogenous pool of phytohormones. Colonization of these plant growth promoting rhizobacteria isolated from rhizosplane and soil of different crops was evaluated on different root types to establish if the mechanism of host specificity exist. The bacteria were isolated from maize, wheat, rice, canola and cotton and phytohormone production was detected and quantified by HPLC. Bacteria were inoculated on surface sterilized seeds of different crops and seeds were germinated. After 7 days the bacteria were re-isolated from the roots and the effect of these bacteria was observed by measuring increase in root length. Bacteria isolated from one plant family (monocots) having fibrous root performed well on similar root system and failed to give significant results on other roots (tap root) of dicots. Some aggressive strains were able to colonize both root systems. The plant growth promoting activities of the bacteria were optimum on the same plant from whom roots they were isolated. The results suggest that bacteria adapt to the root they naturally inhabit and colonize the same plant root systems preferably. Although the observe trend indicate host specificity but some bacteria were aggressive colonizers which grew on all the plants used in experiment. (author)

  20. Paenibacillus oenotherae sp. nov. and Paenibacillus hemerocallicola sp. nov., isolated from the roots of herbaceous plants.

    Science.gov (United States)

    Kim, Tae-Su; Han, Ji-Hye; Joung, Yochan; Kim, Seung Bum

    2015-08-01

    Two Gram-staining-positive, aerobic, endospore-forming, motile bacteria, strains DT7-4T and DLE-12T, were isolated from roots of evening primrose (Oenothera biennis) and day lily (Hemerocallis fulva), respectively, and subjected to taxonomic characterization. Analysis of 16S rRNA gene sequences indicated that the two strains fell into two distinct phylogenetic clusters belonging to the genus Paenibacillus. Strain DT7-4T was most closely related to Paenibacillus phyllosphaerae PALXIL04T and Paenibacillus taihuensis THMBG22T, with 96.3% 16S rRNA gene sequence similarity to each, and strain DLE-12T was most closely related to Paenibacillus ginsengarvi Gsoil 139T and Paenibacillus hodogayensis SGT, with 96.6 and 93.3% sequence similarity, respectively. Both isolates contained anteiso-C15 : 0 as the dominant fatty acid, meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan and MK-7 as the respiratory menaquinone. The cellular polar lipids were composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unidentified polar lipids. The DNA G+C contents of strains DT7-4T and DLE-12T were 50.1 ± 0.7 and 55.2 ± 0.5 mol%, respectively. The chemotaxonomic properties of both isolates were typical of members of the genus Paenibacillus. However, our biochemical and phylogenetic analyses distinguished each isolate from related species. Based on our polyphasic taxonomic analysis, strains DT7-4T and DLE-12T should be recognized as representatives of novel species of Paenibacillus, for which the names Paenibacillus oenotherae sp. nov. (type strain DT7-4T = KCTC 33186T = JCM 19573T) and Paenibacillus hemerocallicola sp. nov. (type strain DLE-12T = KCTC 33185T = JCM 19572T) are proposed.

  1. In vitro antagonistic activity, plant growth promoting traits and phylogenetic affiliation of rhizobacteria associated with wild plants grown in arid soil.

    Science.gov (United States)

    El-Sayed, Wael S; Akhkha, Abdellah; El-Naggar, Moustafa Y; Elbadry, Medhat

    2014-01-01

    The role of plant growth-promoting rhizobacteria (PGPR) in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with 11 wild plant species from the arid soil of Almadinah Almunawarah, Kingdom of Saudi Arabia (KSA) were investigated. From a total of 531 isolates, only 66 bacterial isolates were selected based on their ability to inhibit Fusarium oxysporum, and Sclerotinia sclerotiorum. The selected isolates were screened in vitro for activities related to plant nutrition and plant growth regulation as well as for antifungal and nematicidal traits. Isolated bacteria were found to exhibit capabilities in fix atmospheric nitrogen, produce ammonia, indoleacetic acid (IAA), siderophores, solubilize phosphate and zinc, and showed an antagonistic potential against some phytopathogenic fungi and one nematode species (Meloidogyne incognita) to various extent. Isolates were ranked by their potential ability to function as PGPR. The 66 isolates were genotyped using amplified rDNA restriction analysis (ARDRA) and 16S rRNA gene sequence analysis. The taxonomic composition of the representative genotypes from both rhizosphere and rhizoplane comprised Bacillus, Enterobacter and Pseudomonas. Out of the 10 genotypes, three strains designated as PHP03, CCP05, and TAP02 might be regarded as novel strains based on their low similarity percentages and high bootstrap values. The present study clearly identified specific traits in the isolated rhizobacteria, which make them good candidates as PGPR and might contribute to plant adaption to arid environments. Application of such results in agricultural fields may improve and enhance plant growth in arid soils.

  2. In vitro Antagonistic Activity, Plant Growth Promoting Traits and Phylogenetic Affiliation of Rhizobacteria Associated with Wild Plants Grown in Arid Soil

    Directory of Open Access Journals (Sweden)

    Wael Samir El-Sayed

    2014-12-01

    Full Text Available The role of plant growth-promoting rhizobacteria (PGPR in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with eleven wild plant species from the arid soil of Almadinah Almunawarah, Kingdom of Saudi Arabia (KSA were investigated. From a total of 531 isolates, only 66 bacterial isolates were selected based on their ability to inhibit Fusarium oxysporum, and Sclerotinia sclerotiorum. The selected isolates were screened in vitro for activities related to plant nutrition and plant growth regulation as well as for antifungal and nematicidal traits. Isolated bacteria were found to exhibit capabilities in fix atmospheric nitrogen, produce ammonia, indoleacetic acid (IAA, siderophores, solubilize phosphate and zinc, and showed an antagonistic potential against some phytopathogenic fungi and one nematode species (Meloidogyne incognita to various extent. Isolates were ranked by their potential ability to function as PGPR. The 66 isolates were genotyped using amplified rDNA restriction analysis (ARDRA and 16S rRNA gene sequence analysis. The taxonomic composition of the representative genotypes from both rhizosphere and rhizoplane comprised Bacillus, Enterobacter and Pseudomonas. Out of the ten genotypes, three strains designated as PHP03, CCP05, and TAP02 might be regarded as novel strains based on their low similarity percentages and high bootstrap values. The present study clearly identified specific traits in the isolated rhizobacteria, which make them good candidates as PGPR and might contribute to plant adaption to arid environments. Application of such results in agricultural fields may improve and enhance plant

  3. IAA-producing rhizobacteria from chickpea (Cicer arietinum L.) induce changes in root architecture and increase root biomass.

    Science.gov (United States)

    Fierro-Coronado, Rosario Alicia; Quiroz-Figueroa, Francisco Roberto; García-Pérez, Luz María; Ramírez-Chávez, Enrique; Molina-Torres, Jorge; Maldonado-Mendoza, Ignacio Eduardo

    2014-10-01

    Rhizobacteria promote and have beneficial effects on plant growth, making them useful to agriculture. Nevertheless, the rhizosphere of the chickpea plant has not been extensively examined. The aim of the present study was to select indole-3-acetic acid (IAA) producing rhizobacteria from the rhizosphere of chickpea plants for their potential use as biofertilizers. After obtaining a collection of 864 bacterial isolates, we performed a screen using the Salkowski reaction for the presence of auxin compounds (such as IAA) in bacterial Luria-Bertani supernatant (BLBS). Our results demonstrate that the Salkowski reaction has a greater specificity for detecting IAA than other tested auxins. Ten bacterial isolates displaying a wide range of auxin accumulation were selected, producing IAA levels of 5 to 90 μmol/L (according to the Salkowski reaction). Bacterial isolates were identified on the basis of 16S rDNA partial sequences: 9 isolates belonged to Enterobacter, and 1 isolate was classified as Serratia. The effect of BLBS on root morphology was evaluated in Arabidopsis thaliana. IAA production by rhizobacteria was confirmed by means of a DR5::GFP construct that is responsive to IAA, and also by HPLC-GC/MS. Finally, we observed that IAA secreted by rhizobacteria (i) modified the root architecture of A. thaliana, (ii) caused an increase in chickpea root biomass, and (iii) activated the green fluorescent protein (GFP) reporter gene driven by the DR5 promoter. These findings provide evidence that these novel bacterial isolates may be considered as putative plant-growth-promoting rhizobacteria modifying root architecture and increasing root biomass.

  4. Evaluation of multifarious plant growth promoting traits, antagonistic potential and phylogenetic affiliation of rhizobacteria associated with commercial tea plants grown in Darjeeling, India.

    Science.gov (United States)

    Dutta, Jintu; Thakur, Debajit

    2017-01-01

    Plant growth promoting rhizobacteria (PGPR) are studied in different agricultural crops but the interaction of PGPR of tea crop is not yet studied well. In the present study, the indigenous tea rhizobacteria were isolated from seven tea estates of Darjeeling located in West Bengal, India. A total of 150 rhizobacterial isolates were screened for antagonistic activity against six different fungal pathogens i.e. Nigrospora sphaerica (KJ767520), Pestalotiopsis theae (ITCC 6599), Curvularia eragostidis (ITCC 6429), Glomerella cingulata (MTCC 2033), Rhizoctonia Solani (MTCC 4633) and Fusarium oxysporum (MTCC 284), out of which 48 isolates were antagonist to at least one fungal pathogen used. These 48 isolates exhibited multifarious antifungal properties like the production of siderophore, chitinase, protease and cellulase and also plant growth promoting (PGP) traits like IAA production, phosphate solubilization, ammonia and ACC deaminase production. Amplified ribosomal DNA restriction analysis (ARDRA) and BOX-PCR analysis based genotyping clustered the isolates into different groups. Finally, four isolates were selected for plant growth promotion study in two tea commercial cultivars TV-1 and Teenali-17 in nursery conditions. The plant growth promotion study showed that the inoculation of consortia of these four PGPR isolates significantly increased the growth of tea plant in nursery conditions. Thus this study underlines the commercial potential of these selected PGPR isolates for sustainable tea cultivation.

  5. Evaluation of multifarious plant growth promoting traits, antagonistic potential and phylogenetic affiliation of rhizobacteria associated with commercial tea plants grown in Darjeeling, India.

    Directory of Open Access Journals (Sweden)

    Jintu Dutta

    Full Text Available Plant growth promoting rhizobacteria (PGPR are studied in different agricultural crops but the interaction of PGPR of tea crop is not yet studied well. In the present study, the indigenous tea rhizobacteria were isolated from seven tea estates of Darjeeling located in West Bengal, India. A total of 150 rhizobacterial isolates were screened for antagonistic activity against six different fungal pathogens i.e. Nigrospora sphaerica (KJ767520, Pestalotiopsis theae (ITCC 6599, Curvularia eragostidis (ITCC 6429, Glomerella cingulata (MTCC 2033, Rhizoctonia Solani (MTCC 4633 and Fusarium oxysporum (MTCC 284, out of which 48 isolates were antagonist to at least one fungal pathogen used. These 48 isolates exhibited multifarious antifungal properties like the production of siderophore, chitinase, protease and cellulase and also plant growth promoting (PGP traits like IAA production, phosphate solubilization, ammonia and ACC deaminase production. Amplified ribosomal DNA restriction analysis (ARDRA and BOX-PCR analysis based genotyping clustered the isolates into different groups. Finally, four isolates were selected for plant growth promotion study in two tea commercial cultivars TV-1 and Teenali-17 in nursery conditions. The plant growth promotion study showed that the inoculation of consortia of these four PGPR isolates significantly increased the growth of tea plant in nursery conditions. Thus this study underlines the commercial potential of these selected PGPR isolates for sustainable tea cultivation.

  6. BIOFERTILIZATION WITH RHIZOBACTERIA AND A CONSORTIUM OF ARBUSCULAR MYCORRHIZAL FUNGI IN CITRUS ROOTSTOCKS

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    Roberto Gregorio Chiquito-Contreras

    2012-11-01

    Full Text Available Biofertilization of plants with rhizobacteria and vesicular arbuscular mycorrhizae (mycorrhizal consortium, potentially promotes plant growth and health, and reduces the use of agrochemicals. The effect of individual and combined biofertilization with three strains of rhizobacteria and the mycorrhizal consortium (MTZ-1 was evaluated under nursery conditions on the growth of rootstocks of Citrus volkameriana and Rangpur lime grafted with Tahiti lime. Plants were inoculated individually and combined with the rhizobacteria strains FCA-8, FCA-56 and FCA-60 of Pseudomonas putida, and with MTZ-1; 50 % fertilization also was applied (18-46-00 N-P-K and compared with controls that received nursery management and 100 % fertilization. A split-plot experimental design with five replications per treatment was established. Individual and combined biofertilization with the three strains of bacteria and MTZ-1 positively promoted the growth of C. volkameriana, and Rangpur lime grafted with Tahiti lime, similar to the control with 100 % fertilization. The nutrient content of Tahiti lime leaves was similar to the control for both rootstocks. The presence of rhizobacterial and mycorrhizal populations in the combined biofertilization treatments demonstrated a positive synergism in the colonization of rootstock roots. Results demonstrate the potential of the three strains of P. putida and the MTZ-1 mycorrhizal consortium on the promotion of plant growth and assimilation of nutrients.

  7. Role of Plant Growth Promoting Rhizobacteria in Agricultural Sustainability—A Review

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    Pravin Vejan

    2016-04-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional balance, inducing resistance against plant pathogens, and solubilizing nutrients for easy uptake by plants. In addition, PGPR show synergistic and antagonistic interactions with microorganisms within the rhizosphere and beyond in bulk soil, which indirectly boosts plant growth rate. There are many bacteria species that act as PGPR, described in the literature as successful for improving plant growth. However, there is a gap between the mode of action (mechanism of the PGPR for plant growth and the role of the PGPR as biofertilizer—thus the importance of nano-encapsulation technology in improving the efficacy of PGPR. Hence, this review bridges the gap mentioned and summarizes the mechanism of PGPR as a biofertilizer for agricultural sustainability.

  8. Role of Plant Growth Promoting Rhizobacteria in Agricultural Sustainability-A Review.

    Science.gov (United States)

    Vejan, Pravin; Abdullah, Rosazlin; Khadiran, Tumirah; Ismail, Salmah; Nasrulhaq Boyce, Amru

    2016-04-29

    Plant growth promoting rhizobacteria (PGPR) shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional balance, inducing resistance against plant pathogens, and solubilizing nutrients for easy uptake by plants. In addition, PGPR show synergistic and antagonistic interactions with microorganisms within the rhizosphere and beyond in bulk soil, which indirectly boosts plant growth rate. There are many bacteria species that act as PGPR, described in the literature as successful for improving plant growth. However, there is a gap between the mode of action (mechanism) of the PGPR for plant growth and the role of the PGPR as biofertilizer-thus the importance of nano-encapsulation technology in improving the efficacy of PGPR. Hence, this review bridges the gap mentioned and summarizes the mechanism of PGPR as a biofertilizer for agricultural sustainability.

  9. Application of Rhizobacteria for Plant Growth Promotion Effect and Biocontrol of Anthracnose Caused by Colletotrichum acutatum on Pepper

    Science.gov (United States)

    Lamsal, Kabir; Kim, Sang Woo; Kim, Yun Seok

    2012-01-01

    In vitro and greenhouse screening of seven rhizobacterial isolates, AB05, AB10, AB11, AB12, AB14, AB15 and AB17, was conducted to investigate the plant growth promoting activities and inhibition against anthracnose caused by Colletotrichum acutatum in pepper. According to identification based on 16S rDNA sequencing, the majority of the isolates are members of Bacillus and a single isolate belongs to the genus Paenibacillus. All seven bacterial isolates were capable of inhibiting C. acutatum to various degrees. The results primarily showed that antibiotic substances produced by the selected bacteria were effective and resulted in strong antifungal activity against the fungi. However, isolate AB15 was the most effective bacterial strain, with the potential to suppress more than 50% mycelial growth of C. acutatum in vitro. Moreover, antibiotics from Paenibacillus polymyxa (AB15) and volatile compounds from Bacillus subtilis (AB14) exerted efficient antagonistic activity against the pathogens in a dual culture assay. In vivo suppression activity of selected bacteria was also analyzed in a greenhouse with the reference to their prominent in vitro antagonism efficacy. Induced systemic resistance in pepper against C. acutatum was also observed under greenhouse conditions. Where, isolate AB15 was found to be the most effective bacterial strain at suppressing pepper anthracnose under greenhouse conditions. Moreover, four isolates, AB10, AB12, AB15, and AB17, were identified as the most effective growth promoting bacteria under greenhouse conditions, with AB17 inducing the greatest enhancement of pepper growth. PMID:23323049

  10. Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes

    Directory of Open Access Journals (Sweden)

    Sheikh Hasna Habib

    2016-01-01

    Full Text Available Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR containing 1-aminocyclopropane-1-carboxylate (ACC deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress.

  11. Effect of some plant growth promoting rhizobacteria and nitrogen fertilizer on morphological characteristics of german chamomile (Matricaria chamomilla L.

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    S. Dastborhan

    2016-04-01

    Full Text Available .In order to investigate the effects of plant growth promoting rhizobacteria and nitrogen fertilizer on morphological traits of german chamomile (Matricaria chamomilla L., a field experiment was carried out as factorial based on randomized complete block design with three replications in Research Farm of the Faculty of Agriculture, University of Tabriz, Iran, during 2007-2008. Factors were inoculation with plant growth promoting rhizobacteria (B0: no-inoculation, B1: inoculation with Azotobacter chroocuccum, B2: inoculation with Azospirillum lipoferum and B3: inoculation with a mixture of two bacteria and nitrogen fertilizer (N0:0, N1:50, N2:100 and N3:150 kgN.ha-1. Results showed that inoculation with bacteria significantly improved plant height, stem diameter, number of lateral branches, number of flowers per plant, dry weight of flowers, stems, leaves and total dry weight per plant. These traits were significantly similar for inoculation with Azotobacter, inoculation with Azospirillum and inoculation with a mixture of two bacteria. Effect of nitrogen fertilizer on all traits (except number of lateral branches was positive, but there were no significant differences among 50, 100 and 150 kg.ha-1 nitrogen. The highest and the lowest number and weight of flowers per plant were recorded for inoculation + 50 kg.ha-1 nitrogen application and no-inoculation + no-fertilizer, respectively. In general, application of biofertilizers had positive and significant effects on morphological traits of german chamomile. In addition, with adding 50 kg N.ha-1 the performance of bacteria increased and the highest flower yield were produced.

  12. Effect of two phyto hormone producer rhizobacteria on the bermuda grass growth response and tolerance to phenanthrene

    International Nuclear Information System (INIS)

    Guerrero-Zuniga, A.; Rojas-Contreras, A.; Rodriguez-Dorantes, A.; Montes-Villafan, S.

    2009-01-01

    Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria that have the ability to relieve environmental stress in plants, increasing the plant growth potential. Of importance to phytoremediation, PGPR stimulate plant root development and enhance root growth.This study evaluated the growth response and the tolerance to phenanthrene of Bermuda grass: Cynodon dactylon inoculated with two phytohormone producer rhizobacteria: strains II and III, isolated from a contaminated soil with petroleum hydrocarbons. (Author)

  13. Effect of two phyto hormone producer rhizobacteria on the bermuda grass growth response and tolerance to phenanthrene

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Zuniga, A.; Rojas-Contreras, A.; Rodriguez-Dorantes, A.; Montes-Villafan, S.

    2009-07-01

    Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria that have the ability to relieve environmental stress in plants, increasing the plant growth potential. Of importance to phytoremediation, PGPR stimulate plant root development and enhance root growth.This study evaluated the growth response and the tolerance to phenanthrene of Bermuda grass: Cynodon dactylon inoculated with two phytohormone producer rhizobacteria: strains II and III, isolated from a contaminated soil with petroleum hydrocarbons. (Author)

  14. Streptomyces rhizobacteria modulate the secondary metabolism of Eucalyptus plants.

    Science.gov (United States)

    Salla, Tamiris Daros; da Silva, Ramos; Astarita, Leandro Vieira; Santarém, Eliane Romanato

    2014-12-01

    The genus Eucalyptus comprises economically important species, such as Eucalyptus grandis and Eucalyptus globulus, used especially as a raw material in many industrial sectors. Species of Eucalyptus are very susceptible to pathogens, mainly fungi, which leads to mortality of plant cuttings in rooting phase. One alternative to promote plant health and development is the potential use of microorganisms that act as agents for biological control, such as plant growth-promoting rhizobacteria (PGPR). Rhizobacteria Streptomyces spp have been considered as PGPR. This study aimed at selecting strains of Streptomyces with ability to promote plant growth and modulate secondary metabolism of E. grandis and E. globulus in vitro plants. The experiments assessed the development of plants (root number and length), changes in key enzymes in plant defense (polyphenol oxidase and peroxidase) and induction of secondary compounds(total phenolic and quercetinic flavonoid fraction). The isolate Streptomyces PM9 showed highest production of indol-3-acetic acid and the best potential for root induction. Treatment of Eucalyptus roots with Streptomyces PM9 caused alterations in enzymes activities during the period of co-cultivation (1-15 days), as well as in the levels of phenolic compounds and flavonoids. Shoots also showed alteration in the secondary metabolism, suggesting induced systemic response. The ability of Streptomyces sp. PM9 on promoting root growth, through production of IAA, and possible role on modulation of secondary metabolism of Eucalyptus plants characterizes this isolate as PGPR and indicates its potential use as a biological control in forestry.

  15. Characterization of Effective Rhizobacteria Isolated from Velvet Bean (Mucuna Pruriens) to Enhance Plant Growth

    International Nuclear Information System (INIS)

    Saleem, A. R.; Mahmood, T.; Batool, A.; Khalid, A.

    2016-01-01

    Rhizobacteria with plant growth promoting ability exist in association with plant roots and ameliorate over all plant development and yield. Numerous species of rhizobacteria have been identified with plant growth promoting ability, which can be attributed to multiple microbial characteristics. In the current study rhizobacterial isolates with best plant growth promotion traits were subjected to screening for plant growth promotion under axenic condition. The results of lab assays revealed that out of five rhizobacterial isolates three of bacterial isolate were Gram -ve and two of them were Gram +ve bacterial group. All isolates found positive for the auxin production and ACC-demainase activity. The isolate HS9 showed highest ACC activity (331 ketobutyrate nmol mg-1 biomass hr-1) and auxin production (3.85 without L-TRP). PGPR increase plant growth by reducing the ethylene release and its inhibitory effects, the role of isolates to decrease ethylene effects was affirmed via classical triple response assay on velvet bean. Furthermore, isolate were assessed for resistance test, three efficient strains (G9, HS9 and H38) exhibited antibiotic resistance for streptomycin, kanamycin and rifampicin at 100 mg L-1in TSB medium. For the purpose of co-inoculation, all three isolates showed positive relation to grow together. The results concluded that rhizobacteria selected from rain fed areas were found effective to improve plant growth with their multiple growth enhancing traits. Therefore, PGPR with various characteristics could be a better option for inoculation and co-inoculation to improve plant growth in well watered and water stressed environment. (author)

  16. Boosting Alfalfa (Medicago sativa L. Production With Rhizobacteria From Various Plants in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ihsanullah Daur

    2018-04-01

    Full Text Available This study focused on rhizobacteria to promote sustainable crop production in arid regions of Saudi Arabia. The study isolated 17 tightly root-adhering rhizobacteria from various plants at Hada Al Sham in Saudi Arabia. All 17 rhizobacterial isolates were confirmed as plant growth promoting rhizobacteria by classical biochemical tests. Using 16S rDNA gene sequence analyses, the strains were identified as Bacillus, Acinetobacter and Enterobacter. Subsequently, the strains were assessed for their ability to improve the physiology, nutrient uptake, growth, and yield of alfalfa plants grown under desert agriculture conditions. The field trials were conducted in a randomized complete block design. Inoculation of alfalfa with any of these 17 strains improved the relative water content; chlorophyll a; chlorophyll b; carotenoid contents; nitrogen (N, phosphorus, and potassium contents; plant height; leaf-to-stem ratio; and fresh and dry weight. Acinetobacter pittii JD-14 was most effective to increase fresh and dry weight of alfalfa by 41 and 34%, respectively, when compared to non-inoculated control plants. Nevertheless, all strains enhanced crop traits when compared to controls plants, indicating that these desert rhizobacterial strains could be used to develop an eco-friendly biofertilizer for alfalfa and possibly other crop plants to enhance sustainable production in arid regions.

  17. Boosting Alfalfa (Medicago sativa L.) Production With Rhizobacteria From Various Plants in Saudi Arabia

    KAUST Repository

    Daur, Ihsanullah; Saad, Maged; Eida, Abdul Aziz; Ahmad, Shakeel; Shah, Zahid Hussain; Ihsan, Muhammad Z.; Muhammad, Yasir; Sohrab, Sayed S.; Hirt, Heribert

    2018-01-01

    This study focused on rhizobacteria to promote sustainable crop production in arid regions of Saudi Arabia. The study isolated 17 tightly root-adhering rhizobacteria from various plants at Hada Al Sham in Saudi Arabia. All 17 rhizobacterial isolates were confirmed as plant growth promoting rhizobacteria by classical biochemical tests. Using 16S rDNA gene sequence analyses, the strains were identified as Bacillus, Acinetobacter and Enterobacter. Subsequently, the strains were assessed for their ability to improve the physiology, nutrient uptake, growth, and yield of alfalfa plants grown under desert agriculture conditions. The field trials were conducted in a randomized complete block design. Inoculation of alfalfa with any of these 17 strains improved the relative water content; chlorophyll a; chlorophyll b; carotenoid contents; nitrogen (N), phosphorus, and potassium contents; plant height; leaf-to-stem ratio; and fresh and dry weight. Acinetobacter pittii JD-14 was most effective to increase fresh and dry weight of alfalfa by 41 and 34%, respectively, when compared to non-inoculated control plants. Nevertheless, all strains enhanced crop traits when compared to controls plants, indicating that these desert rhizobacterial strains could be used to develop an eco-friendly biofertilizer for alfalfa and possibly other crop plants to enhance sustainable production in arid regions.

  18. Boosting Alfalfa (Medicago sativa L.) Production With Rhizobacteria From Various Plants in Saudi Arabia.

    Science.gov (United States)

    Daur, Ihsanullah; Saad, Maged M; Eida, Abdul Aziz; Ahmad, Shakeel; Shah, Zahid Hussain; Ihsan, Muhammad Z; Muhammad, Yasir; Sohrab, Sayed S; Hirt, Heribert

    2018-01-01

    This study focused on rhizobacteria to promote sustainable crop production in arid regions of Saudi Arabia. The study isolated 17 tightly root-adhering rhizobacteria from various plants at Hada Al Sham in Saudi Arabia. All 17 rhizobacterial isolates were confirmed as plant growth promoting rhizobacteria by classical biochemical tests. Using 16S rDNA gene sequence analyses, the strains were identified as Bacillus, Acinetobacter and Enterobacter . Subsequently, the strains were assessed for their ability to improve the physiology, nutrient uptake, growth, and yield of alfalfa plants grown under desert agriculture conditions. The field trials were conducted in a randomized complete block design. Inoculation of alfalfa with any of these 17 strains improved the relative water content; chlorophyll a; chlorophyll b; carotenoid contents; nitrogen (N), phosphorus, and potassium contents; plant height; leaf-to-stem ratio; and fresh and dry weight. Acinetobacter pittii JD-14 was most effective to increase fresh and dry weight of alfalfa by 41 and 34%, respectively, when compared to non-inoculated control plants. Nevertheless, all strains enhanced crop traits when compared to controls plants, indicating that these desert rhizobacterial strains could be used to develop an eco-friendly biofertilizer for alfalfa and possibly other crop plants to enhance sustainable production in arid regions.

  19. Boosting Alfalfa (Medicago sativa L.) Production With Rhizobacteria From Various Plants in Saudi Arabia

    KAUST Repository

    Daur, Ihsanullah

    2018-04-04

    This study focused on rhizobacteria to promote sustainable crop production in arid regions of Saudi Arabia. The study isolated 17 tightly root-adhering rhizobacteria from various plants at Hada Al Sham in Saudi Arabia. All 17 rhizobacterial isolates were confirmed as plant growth promoting rhizobacteria by classical biochemical tests. Using 16S rDNA gene sequence analyses, the strains were identified as Bacillus, Acinetobacter and Enterobacter. Subsequently, the strains were assessed for their ability to improve the physiology, nutrient uptake, growth, and yield of alfalfa plants grown under desert agriculture conditions. The field trials were conducted in a randomized complete block design. Inoculation of alfalfa with any of these 17 strains improved the relative water content; chlorophyll a; chlorophyll b; carotenoid contents; nitrogen (N), phosphorus, and potassium contents; plant height; leaf-to-stem ratio; and fresh and dry weight. Acinetobacter pittii JD-14 was most effective to increase fresh and dry weight of alfalfa by 41 and 34%, respectively, when compared to non-inoculated control plants. Nevertheless, all strains enhanced crop traits when compared to controls plants, indicating that these desert rhizobacterial strains could be used to develop an eco-friendly biofertilizer for alfalfa and possibly other crop plants to enhance sustainable production in arid regions.

  20. Differential growth responses of Brachypodium distachyon genotypes to inoculation with plant growth promoting rhizobacteria.

    Science.gov (United States)

    do Amaral, Fernanda P; Pankievicz, Vânia C S; Arisi, Ana Carolina M; de Souza, Emanuel M; Pedrosa, Fabio; Stacey, Gary

    2016-04-01

    Plant growth promoting rhizobacteria (PGPR) can associate and enhance the growth of important crop grasses. However, in most cases, the molecular mechanisms responsible for growth promotion are not known. Such research could benefit by the adoption of a grass model species that showed a positive response to bacterial inoculation and was amenable to genetic and molecular research methods. In this work we inoculated different genotypes of the model grass Brachypodium distachyon with two, well-characterized PGPR bacteria, Azospirillum brasilense and Herbaspirillum seropedicae, and evaluated the growth response. Plants were grown in soil under no nitrogen or with low nitrogen (i.e., 0.5 mM KNO3). A variety of growth parameters (e.g., shoot height, root length, number of lateral roots, fresh and dry weight) were measured 35 days after inoculation. The data indicate that plant genotype plays a very important role in determining the plant response to PGPR inoculation. A positive growth response was observed with only four genotypes grown under no nitrogen and three genotypes tested under low nitrogen. However, in contrast, relatively good root colonization was seen with most genotypes, as measured by drop plate counting and direct, microscopic examination of roots. In particular, the endophytic bacteria H. seropedicae showed strong epiphytic and endophytic colonization of roots.

  1. Revitalization of plant growth promoting rhizobacteria for sustainable development in agriculture.

    Science.gov (United States)

    Gouda, Sushanto; Kerry, Rout George; Das, Gitishree; Paramithiotis, Spiros; Shin, Han-Seung; Patra, Jayanta Kumar

    2018-01-01

    The progression of life in all forms is not only dependent on agricultural and food security but also on the soil characteristics. The dynamic nature of soil is a direct manifestation of soil microbes, bio-mineralization, and synergistic co-evolution with plants. With the increase in world's population the demand for agriculture yield has increased tremendously and thereby leading to large scale production of chemical fertilizers. Since the use of fertilizers and pesticides in the agricultural fields have caused degradation of soil quality and fertility, thus the expansion of agricultural land with fertile soil is near impossible, hence researchers and scientists have sifted their attention for a safer and productive means of agricultural practices. Plant growth promoting rhizobacteria (PGPR) has been functioning as a co-evolution between plants and microbes showing antagonistic and synergistic interactions with microorganisms and the soil. Microbial revitalization using plant growth promoters had been achieved through direct and indirect approaches like bio-fertilization, invigorating root growth, rhizoremediation, disease resistance etc. Although, there are a wide variety of PGPR and its allies, their role and usages for sustainable agriculture remains controversial and restricted. There is also variability in the performance of PGPR that may be due to various environmental factors that might affect their growth and proliferation in the plants. These gaps and limitations can be addressed through use of modern approaches and techniques such as nano-encapsulation and micro-encapsulation along with exploring multidisciplinary research that combines applications in biotechnology, nanotechnology, agro biotechnology, chemical engineering and material science and bringing together different ecological and functional biological approaches to provide new formulations and opportunities with immense potential. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Rhizobacteria and plant symbiosis in heavy metal uptake and its implications for soil bioremediation

    NARCIS (Netherlands)

    Sobariu, Dana Luminita; Fertu, Daniela Ionela Tudorache; Diaconu, Mariana; Pavel, Lucian Vasile; Hlihor, Raluca Maria; Drăgoi, Elena Niculina; Curteanu, Silvia; Lenz, Markus; Corvini, Philippe François Xavier; Gavrilescu, Maria

    2016-01-01

    Certain species of plants can benefit from synergistic effects with plant growth-promoting rhizobacteria (PGPR) that improve plant growth and metal accumulation, mitigating toxic effects on plants and increasing their tolerance to heavy metals. The application of PGPR as biofertilizers and

  3. Isolation and identification of plant growth promoting rhizobacteria from maize (Zea mays L. rhizosphere and their plant growth promoting effect on rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Karnwal Arun

    2017-06-01

    Full Text Available The use of plant growth promoting rhizobacteria is increasing in agriculture and gives an appealing manner to replace chemical fertilizers, pesticides, and dietary supplements. The objective of our research was to access the plant growth promotion traits of Pseudomonas aeruginosa, P. fluorescens and Bacillus subtilis isolated from the maize (Zea mays L. rhizosphere. In vitro studies showed that isolates have the potential to produce indole acetic acid (IAA, hydrogen cyanide, phosphate solubilisation, and siderophore. RNA analysis revealed that two isolates were 97% identical to P. aeruginosa strain DSM 50071 and P. aeruginosa strain NBRC 12689 (AK20 and AK31, while two others were 98% identical to P. fluorescens strain ATCC 13525, P. fluorescens strain IAM 12022 (AK18 and AK45 and one other was 99% identical to B. subtilis strain NCDO 1769 (AK38. Our gnotobiotic study showed significant differences in plant growth variables under control and inoculated conditions. In the present research, it was observed that the isolated strains had good plant growth promoting effects on rice.

  4. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid

    2016-06-17

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  5. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid; Daur, Ihsanullah; Al-Solaimani, Samir G.; Ahmad, Shakeel; Madkour, Mohamed H.; Yasir, Muhammad; Hirt, Heribert; Ali, Shawkat; Ali, Zahir

    2016-01-01

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  6. Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat.

    Science.gov (United States)

    Naeem, Muhammad; Aslam, Zubair; Khaliq, Abdul; Ahmed, Jam Nazir; Nawaz, Ahmad; Hussain, Mubshar

    2018-04-24

    Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1tiller -1 ), and highest plant height (85.8cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320m -2 ), straw yield (8.6Mgha -1 ), and grain yield (4.8Mgha -1 ) were achieved when seeds were inoculated with Bacillus sp. strain 6+Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6+Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  7. Structural and functional diversity of rhizobacteria associated with Rauwolfia spp. across the Western Ghat regions of Karnataka, India.

    Science.gov (United States)

    Prasanna Kumar, S P; Hariprasad, P; Brijesh Singh, S; Gowtham, H G; Niranjana, S R

    2014-01-01

    The present study carried out with denaturing gradient gel electrophoresis of DNA extracted from rhizosphere soils of Rauwolfia spp. collected from Western Ghat (WG) regions of Karnataka indicated that Pseudomonas sp. was prevalently found followed by Methylobacterium sp., Bacillus sp. and uncultured bacteria. A total of 200 rhizobacteria were isolated from 58 rhizosphere soil samples comprising of 15 different bacterial genera. The Shannon Weaver diversity index (H') and Simpson's diversity index (D) were found to be 2.57 and 0.91 for cultivable bacteria, respectively. The total species richness of cultivable rhizobacteria was high in Coorg district comprising 15 bacterial genera while in Mysore district, four bacterial genera were recorded. Rarefaction curve analysis also indicated the presence of higher species richness in samples of Shimoga and Coorg. All the rhizobacteria were screened for their multiple plant growth promotion and disease suppression traits. The results revealed that 70% of the isolates colonized tomato roots, 42% produced indole acetic acid, 55% solubilized phosphorus, while 43, 22, 27, 19, 40, 15 and 44% produced siderophore, salicylic acid, hydrogen cyanide, chitinase, phytase, cellulase and protease, respectively. Rhizobacterial isolates showing antagonistic activity against Fusarium oxysporum and Aspergillus flavus were 53 and 33%, respectively. Plant growth promotion studies revealed that most of the isolates increased percent germination with significantly higher vigour index as compared to untreated control. Most predominant rhizobacteria found in the rhizospheres of Rauwolfia spp. of WG regions are potential PGPR which can serve as biofertilizers and biopesticides.

  8. Induced Systemic Tolerance to Multiple Stresses Including Biotic and Abiotic Factors by Rhizobacteria

    Directory of Open Access Journals (Sweden)

    Sung-Je Yoo

    2017-06-01

    Full Text Available Recently, global warming and drastic climate change are the greatest threat to the world. The climate change can affect plant productivity by reducing plant adaptation to diverse environments including frequent high temperature; worsen drought condition and increased pathogen transmission and infection. Plants have to survive in this condition with a variety of biotic (pathogen/pest attack and abiotic stress (salt, high/low temperature, drought. Plants can interact with beneficial microbes including plant growth-promoting rhizobacteria, which help plant mitigate biotic and abiotic stress. This overview presents that rhizobacteria plays an important role in induced systemic resistance (ISR to biotic stress or induced systemic tolerance (IST to abiotic stress condition; bacterial determinants related to ISR and/or IST. In addition, we describe effects of rhizobacteria on defense/tolerance related signal pathway in plants. We also review recent information including plant resistance or tolerance against multiple stresses (bioticabiotic. We desire that this review contribute to expand understanding and knowledge on the microbial application in a constantly varying agroecosystem, and suggest beneficial microbes as one of alternative environment-friendly application to alleviate multiple stresses.

  9. RHIZOBACTERIA AS BIOCONTROL AGENTS OF ROOT ROT DISEASE ON SHALLOT

    Directory of Open Access Journals (Sweden)

    Nunik Iriyanti Ramadhan

    2015-01-01

    Full Text Available Shallot is a high-economic value commodity, but so far the supply is still lower than the demand. One of the production problem is “moler” disease of shallot (MDS caused by Fusarium oxysporum f.sp. cepae (FOCe. The aim of this research was to study the potentiality of shallot rhizobacteria (SRB from various soil ordo to inhibit (MDS. This research was held in the Laboratory of Biology and Soil Health and Greenhouse at UNS. This research was carried out by exploring rhizobacteria of shallot planted on Entisols, Andisols, and Vertisols. Rhizobacteria exploration results were tested for their ability to control Fusarium oxysporum f.sp.cepae (FOCe. Inhibitory ability test of SRB to FOCe was carried out in vitro and on shallot in the greenhouse. The green house research used a Completely Randomized Design (CDR with two factors. The first factor was rhizobacteria combination and the second factor was various soil ordo (Andisols, Entisols, and Vertisols. Each treatment was replicated three times. It was obtained three rhizobacteria isolates from Vertisols (B15: 70%, Andisols (B12:45,55%, and Entisols (B10:46,67% being the highest inhibition results to FOCe. The combination of rhizobacteria B12 and B10 provided the lowest intensity.

  10. Paenibacillus kyungheensis sp. nov., isolated from flowers of magnolia.

    Science.gov (United States)

    Siddiqi, Muhammad Zubair; Siddiqi, Muhammad Hanif; Im, Wan Taek; Kim, Yeon-Ju; Yang, Deok-Chun

    2015-11-01

    A Gram-staining-positive, catalase-positive, oxidase-negative, facultatively anaerobic, rod-shaped bacterium designated strain DCY88T, was isolated from flowers of magnolia. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Paenibacillus that was closely related to Paenibacillus hordei RH-N24T (97.8 %). The other most closely related species were Paenibacillus illinoisensis NRRL NRS-1356T (94.3 %), Paenibacillus hunanensis DSM 22170T (94.2 %), Paenibacillus peoriae DSM 8320T (93.9 %), Paenibacillus kribbensis Am49T (93.8 %) and the type species of the genus, Paenibacillus polymyxa ATCC 842T (93.3 %). Cells of the strain were endospore-forming and motile by peritrichous flagella. Strain DCY88T formed pink-pigmented colonies on trypticase soy agar and R2A agar medium. Growth of strain DCY88T occurs at temperatures 5-37 °C, at pH 4-9 and 0.5-5.5 % NaCl (w/v). The menaquinone was MK-7.The cell wall peptidoglycan of strain DCY88T contained meso-diaminopimelic acid. The major fatty acids were anteiso-C15 : 0 (61.0 %) and C16 : 0 (11.0 %). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified polar lipid. The strain DCY88T contained spermidine as the major polyamine. The DNA G+C content was 51.6 mol%. The DNA-DNA hybridization relatedness between strain DCY88T and P. hordei RH-N24T was 48 ± 2 %. The phenotypic, phylogenetic and chemotaxonomic results indicate that the strain DCY88T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus kyungheensis sp. nov. is proposed. The type strain is DCY88T ( = JCM 19886T = KCTC 33429T).

  11. Characterization of rhizobacteria associated to maize crop in IAA, siderophores and salicylic acid metabolite production

    Directory of Open Access Journals (Sweden)

    Annia Hernández

    2004-01-01

    Full Text Available It has been demonstrated that rhizobacteria are able to produce metabolites having agricultural interest, including salicylic acid, the siderophores and phytohormones. Indol acetic acid (IAA is the most well-known and studied auxin, playing a governing role in culture growth. The object of this work was to characterise rhizobacteria associated with the maize crop in terms of producing IAA, siderophores and salicylic acid metabolites. Burkholderia cepacia and Pseudomonas fluorescens strains previously isolated from maize Francisco variety rhizosphere were used. Colorimetric and chromatographic techniques for detecting these metabolites were studied; multi-variable analysis of hierarchic conglomerate and complete ligament were used for selecting the best strains for producing metabolites of interest. These results demonstrated that all rhizobacteria strains studied produced IAA, siderophores and salicylic acid metabolites. Burkholderia cepacia MBf21, MBp1, MBp2, MBf22, MBp3, MBf20, MBf 15 and Pseudomonas fluorescens MPp4strains have presented the greatest production of these metabolites, showing that these strains could be used in promoting vegetal growth in economically important cultures. Key words: Pseudomonas fluorescens, Burkholderia cepacia, IAA, siderophore, salicylic acid.

  12. Phytomanagement of Cd-contaminated soils using maize (Zea mays L.) assisted by plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Moreira, Helena; Marques, Ana P G C; Franco, Albina R; Rangel, António O S S; Castro, Paula M L

    2014-01-01

    Zea mays (L.) is a crop widely cultivated throughout the world and can be considered suitable for phytomanagement due to its metal resistance and energetic value. In this study, the effect of two plant growth-promoting rhizobacteria, Ralstonia eutropha and Chryseobacterium humi, on growth and metal uptake of Z. mays plants in soils contaminated with up to 30 mg Cd kg(-1) was evaluated. Bacterial inoculation increased plant biomass up to 63% and led to a decrease of up to 81% in Cd shoot levels (4-88 mg Cd kg(-1)) and to an increase of up to 186% in accumulation in the roots (52-134 mg Cd kg(-1)). The rhizosphere community structure changed throughout the experiment and varied with different levels of Cd soil contamination, as revealed by molecular biology techniques. Z. mays plants inoculated with either of the tested strains may have potential application in a strategy of soil remediation, in particular short-term phytostabilization, coupled with biomass production for energy purposes.

  13. Effects of rhizobacteria on the respiration and growth of Cerasus sachalinensis Kom. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Qin, S.; Zhou, W.; Li, Z.; Lyu, D.

    2016-11-01

    In this study, we investigated the influence of rhizosphere microorganisms on seed germination and root metabolism in Cerasus sachalinensis Kom. We inoculated C. sachalinensis plants with suspensions of dominant bacterial strains isolated from their rhizosphere. Four bacterial strains each with significant growth-promoting or growth-inhibiting effects were screened from the efficient root-colonizing microorganisms. The number of actinomycetes increased and that of fungi decreased significantly in the seedling rhizospheres after rhizobacteria treatment. The growth-promoting bacteria slightly affected the respiration rates and respiratory pathway enzymes, but significantly improved root viability, root carbohydrate concentration and seedling growth. Bacillus cereus, Staphylococcus sp. and Pseudomonas fluorescens were identified as the growth-promoting rhizobacteria; one strain could not be identified. After inoculation with the growth-inhibiting bacteria, the number of fungal colonies in the seedling rhizospheres increased and root viability and respiration rate as well as starch and sucrose accumulation in the roots significantly decreased. The glycolysis, pentose phosphate and alternative oxidase pathways became the major pathways of respiratory metabolism after inoculation with the growth-inhibiting bacteria. The height, leaf number, growth and dry weight of the seedlings decreased significantly in plants inoculated with the growth-inhibiting bacteria. Inoculation of C. sachalinensis rhizosphere with growth-promoting and growth-inhibiting bacteria affected the soil environmental factors such as microbial group composition, nutrient concentration and seedling biomass. (Author)

  14. Production of an antimicrobial substance against Cryptococcus neoformans by Paenibacillus brasilensis Sa3 isolated from the rhizosphere of Kalanchoe brasiliensis.

    Science.gov (United States)

    Fortes, Tiago Oliveira; Alviano, Daniela Sales; Tupinambá, Gleiser; Padrón, Thaís Souto; Antoniolli, Angelo Roberto; Alviano, Celuta Sales; Seldin, Lucy

    2008-01-01

    An antifungal substance produced by Paenibacillus brasilensis strain Sa3 was preliminary characterized and showed to be stable after treatment with different enzymes and organic solvents and at a wide range of pH, and presented a molecular weight between 3 and 10 kDa. In vitro antagonism of this strain towards Cryptococcus neoformans was investigated by optical and electronic microscopic analyses and a fungicidal effect on C. neoformans was observed. Ultrastructural analysis showed intense changes on the fungus when it was paired cultured with strain Sa3, mainly the detachment of the capsule from the cell wall and the presence of altered organelles in the cytoplasm. This novel antifungal substance produced by P. brasilensis Sa3 may represent a new insight in antifungal therapy mainly against emergent fungi. Also, prospective studies on rhizobacteria of plants as Kalanchoe brasiliensis may offer a potential source for the discovery of bioactive compounds with medical value.

  15. Comparative genomic analysis of four representative plant growth-promoting rhizobacteria in Pseudomonas

    Science.gov (United States)

    2013-01-01

    Background Some Pseudomonas strains function as predominant plant growth-promoting rhizobacteria (PGPR). Within this group, Pseudomonas chlororaphis and Pseudomonas fluorescens are non-pathogenic biocontrol agents, and some Pseudomonas aeruginosa and Pseudomonas stutzeri strains are PGPR. P. chlororaphis GP72 is a plant growth-promoting rhizobacterium with a fully sequenced genome. We conducted a genomic analysis comparing GP72 with three other pseudomonad PGPR: P. fluorescens Pf-5, P. aeruginosa M18, and the nitrogen-fixing strain P. stutzeri A1501. Our aim was to identify the similarities and differences among these strains using a comparative genomic approach to clarify the mechanisms of plant growth-promoting activity. Results The genome sizes of GP72, Pf-5, M18, and A1501 ranged from 4.6 to 7.1 M, and the number of protein-coding genes varied among the four species. Clusters of Orthologous Groups (COGs) analysis assigned functions to predicted proteins. The COGs distributions were similar among the four species. However, the percentage of genes encoding transposases and their inactivated derivatives (COG L) was 1.33% of the total genes with COGs classifications in A1501, 0.21% in GP72, 0.02% in Pf-5, and 0.11% in M18. A phylogenetic analysis indicated that GP72 and Pf-5 were the most closely related strains, consistent with the genome alignment results. Comparisons of predicted coding sequences (CDSs) between GP72 and Pf-5 revealed 3544 conserved genes. There were fewer conserved genes when GP72 CDSs were compared with those of A1501 and M18. Comparisons among the four Pseudomonas species revealed 603 conserved genes in GP72, illustrating common plant growth-promoting traits shared among these PGPR. Conserved genes were related to catabolism, transport of plant-derived compounds, stress resistance, and rhizosphere colonization. Some strain-specific CDSs were related to different kinds of biocontrol activities or plant growth promotion. The GP72 genome

  16. Plant-mediated restriction of Salmonella enterica on tomato and spinach leaves colonized with Pseudomonas plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Hsu, Chiun-Kang; Micallef, Shirley A

    2017-10-16

    Reducing Salmonella enterica association with plants during crop production could reduce risks of fresh produce-borne salmonellosis. Plant growth-promoting rhizobacteria (PGPR) colonizing plant roots are capable of promoting plant growth and boosting resistance to disease, but the effects of PGPR on human pathogen-plant associations are not known. Two root-colonizing Pseudomonas strains S2 and S4 were investigated in spinach, lettuce and tomato for their plant growth-promoting properties and their influence on leaf populations of S. enterica serovar Newport. Plant roots were inoculated with Pseudomonas in the seedling stage. At four (tomato) and six (spinach and lettuce) weeks post-germination, plant growth promotion was assessed by shoot dry weight (SDW) and leaf chlorophyll content measurements. Leaf populations of S. Newport were measured after 24h of leaf inoculation with this pathogen by direct plate counts on Tryptic Soy Agar. Root inoculation of spinach cv. 'Tyee', with Pseudomonas strain S2 or S4 resulted in a 69% and 63% increase in SDW compared to non-inoculated controls (pgrowth by over 40% compared to controls (pgrowth promotion was detected in tomato cv. 'BHN602', but S2-inoculated plants had elevated leaf chlorophyll content (13%, pgrowth, but also reduce the fitness of epiphytic S. enterica in the phyllosphere. Plant-mediated effects induced by PGPR may be an effective strategy to minimize contamination of crops with S. enterica during cultivation. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Specific interactions between arbuscular mycorrhizal fungi and plant growth-promoting bacteria--as revealed by different combinations

    Energy Technology Data Exchange (ETDEWEB)

    Jaderlund, Lotta; Arthurson, Veronica; Granhall, Ulf; Jansson, Janet K.

    2008-05-15

    The interactions between two plant growth promoting rhizobacteria (PGPR), Pseudomonas fluorescens SBW25 and Paenibacillus brasilensis PB177, two arbuscular mycorrhizal (AM) fungi (Glomus mosseae and G. intraradices) and one pathogenic fungus (Microdochium nivale) were investigated on winter wheat (Triticum aestivum cultivar Tarso) in a greenhouse trial. PB177, but not SBW25, had strong inhibitory effects on M. nivale in dual culture plate assays. The results from the greenhouse experiment show very specific interactions; e.g. the two AM fungi react differently when interacting with the same bacteria on plants. G. intraradices (single inoculation or together with SBW25) increased plant dry weight on M. nivale infested plants, suggesting that the pathogenic fungus is counteracted by G. intraradices, but PB177 inhibited this positive effect. This is an example of two completely different reactions between the same AM fungus and two species of bacteria, previously known to enhance plant growth and inhibit pathogens. When searching for plant growth promoting microorganisms it is therefore important to test for the most suitable combination of plant, bacteria and fungi in order to get satisfactory plant growth benefits.

  18. Alleviation of heavy metals toxicity by the application of plant growth promoting rhizobacteria and effects on wheat grown in saline sodic field.

    Science.gov (United States)

    Hassan, Tamoor Ul; Bano, Asghari; Naz, Irum

    2017-06-03

    The aim of the study was to determine tolerance of plant growth promoting rhizobacteria (PGPR) in different concentrations of Cu, Cr, Co, Cd, Ni, Mn, and Pb and to evaluate the PGPR-modulated bioavailability of different heavy metals in the rhizosphere soil and wheat tissues, grown in saline sodic soil. Bacillus cereus and Pseudomonas moraviensis were isolated from Cenchrus ciliaris L. growing in the Khewra salt range. Seven-day-old cultures of PGPR were applied on wheat as single inoculum, co-inoculation and carrier-based biofertilizer (using maize straw and sugarcane husk as carrier). At 100 ppm of Cr and Cu, the survival rates of rhizobacteria were decreased by 40%. Single inoculation of PGPR decreased 50% of Co, Ni, Cr and Mn concentrations in the rhizosphere soil. Co-inoculation of PGPR and biofertilizer treatment further augmented the decreases by 15% in Co, Ni, Cr and Mn over single inoculation except Pb and Co where decreases were 40% and 77%, respectively. The maximum decrease in biological concentration factor (BCF) was observed for Cd, Co, Cr, and Mn. P. moraviensis inoculation decreases the biological accumulation coefficient (BAC) as well as translocation factor (TF) for Cd, Cr, Cu Mn, and Ni. The PGPR inoculation minimized the deleterious effects of heavy metals, and the addition of carriers further assisted the PGPR.

  19. Effect of Plant Growth Promoting Rhizobacteria (PGPR on Phenological Traits, Grain Yield and Yield Components of Three Maize (Zea mays L. Cultivars

    Directory of Open Access Journals (Sweden)

    A Soleimani Fard

    2013-11-01

    Full Text Available To evaluate the effect of bio-fertilize on yield and its components in maize cultivars, an split plot experiment based on randomized complete bock design with three replications in was conducted in Payam-noor University of Ilam, Iran, in 2009-2010. Treatments were cultivar (SC604, SC704 and SC807 assigned to main plots and bio-fertilizer (non- inoculation, inoculation with Azetobacter, Azospirillum and dual inoculation ofAzotobacterand Azospirillum to subplots. The effect of cultivar on days to maturity, plant height, dry matter, ear length, stem diameter, number of grain per ear row, 1000-grain weight, grain yield, biological yield and protein content was significant cultivar. SC 704 had the highest dry matter (259.5 g.m-2, plant height (201.1 cm, number of grain per ear row (42.8 grain, grain yield (10850 kg.m-2, and biological yield (22040 kg.m-2. The effect of plant growth promoting rhizobacteria on all traits expect harvest index was significant. Dual inoculation ofAzotobacterand Azospirillum had the longest days to ear initiation (71.2 days, days to maturity (115.4 day, number of leaves above ear (5.6 ear, dry matter (240.4 g.m-2, ear length (24.3 cm, plant height (212.4 cm, seed number of rows per ear (14.5 row, number of grains per row (44.2 grain, grain yield (10190 kg.m-2, biological yield (21320 kg.m-2 and protein content (10.7%. Interaction effect of cultivar× plant growth promoting rhizobacteria on grain yield was significant. The highest and lowest grain yield was obtained from SC 704 and application of dual inoculation ofAzotobacterand Azospirillum (12320 kg.ha-1 and lowest from SC 604 when inoculation treatments were not used 7570 kg.ha-1 respectively.

  20. Complete Genome Sequence of Paenibacillus strain Y4.12MC10, a Novel Paenibacillus lautus strain Isolated from Obsidian Hot Spring in Yellowstone National Park.

    Science.gov (United States)

    Mead, David A; Lucas, Susan; Copeland, Alex; Lapidus, Alla; Cheng, Jan-Feng; Bruce, David C; Goodwin, Lynne A; Pitluck, Sam; Chertkov, Olga; Zhang, Xiaojing; Detter, John C; Han, Cliff S; Tapia, Roxanne; Land, Miriam; Hauser, Loren J; Chang, Yun-Juan; Kyrpides, Nikos C; Ivanova, Natalia N; Ovchinnikova, Galina; Woyke, Tanja; Brumm, Catherine; Hochstein, Rebecca; Schoenfeld, Thomas; Brumm, Phillip

    2012-07-30

    Paenibacillus sp.Y412MC10 was one of a number of organisms isolated from Obsidian Hot Spring, Yellowstone National Park, Montana, USA under permit from the National Park Service. The isolate was initially classified as a Geobacillus sp. Y412MC10 based on its isolation conditions and similarity to other organisms isolated from hot springs at Yellowstone National Park. Comparison of 16 S rRNA sequences within the Bacillales indicated that Geobacillus sp.Y412MC10 clustered with Paenibacillus species, and the organism was most closely related to Paenibacillus lautus. Lucigen Corp. prepared genomic DNA and the genome was sequenced, assembled, and annotated by the DOE Joint Genome Institute. The genome sequence was deposited at the NCBI in October 2009 (NC_013406). The genome of Paenibacillus sp. Y412MC10 consists of one circular chromosome of 7,121,665 bp with an average G+C content of 51.2%. Comparison to other Paenibacillus species shows the organism lacks nitrogen fixation, antibiotic production and social interaction genes reported in other paenibacilli. The Y412MC10 genome shows a high level of synteny and homology to the draft sequence of Paenibacillus sp. HGF5, an organism from the Human Microbiome Project (HMP) Reference Genomes. This, combined with genomic CAZyme analysis, suggests an intestinal, rather than environmental origin for Y412MC10.

  1. [Growth and photochemical efficiency of photosystem ii in seedlings of two varieties of Capsicum annuum L. inoculated with rhizobacteria and arbuscular mycorrhizal fungi].

    Science.gov (United States)

    Angulo-Castro, Azareel; Ferrera-Cerrato, Ronald; Alarcón, Alejandro; Almaraz-Suárez, Juan José; Delgadillo-Martínez, Julián; Jiménez-Fernández, Maribel; García-Barradas, Oscar

    Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are a biological alternative for the sustainable management of Capsicum annuum L. This research work evaluated the effects of both PGPR and AMF on bell pepper and jalapeno pepper plants. Five bacterial strains isolated from several locations in Estado de Mexico were used: [P61 (Pseudomonas tolaasii), A46 (P. tolaasii), R44 (Bacillus pumilus), BSP1.1 (Paenibacillus sp.), and OLs-Sf5 (Pseudomonas sp.)], and three treatments with AMF [H1 (consortium isolated from pepper crops in the State of Puebla), H2 (Rhizophagus intraradices), and H3 (consortium isolated from the rhizosphere of lemon trees, State of Tabasco)]. In addition, a fertilized treatment (Steiner nutrient solution at 25%) and an unfertilized control were included. Seedlings of "Caloro" jalapeno pepper and "California Wonder" bell pepper were inoculated with AMF at seed sowing, and PGPR were inoculated after 15 days of seedling emergence; seedlings were grown under plant growth chamber conditions. P61 bacterium and H1 AMF consortia were the most effective microorganisms for jalapeno pepper whereas R44 bacterium and AMF H3 and H1 were the most effective for bell peppers, when compared to the unfertilized control. Furthermore, P61 and R44 bacteria showed beneficial effects on PSII efficiency. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Effects of Nano-Zinc oxide and Seed Inoculation by Plant Growth Promoting Rhizobacteria (PGPR on Yield, Yield Components and Grain Filling Period of Soybean (Glycine max L.

    Directory of Open Access Journals (Sweden)

    R. Seyed Sharifi

    2016-02-01

    Full Text Available Introduction Utilizing biological fertilizer is a proper and cheap method for crop production. Potentially, soybean can be used as biological fertilizers and seed inoculation. Zinc is an essential element that have positive effects on plant growth and its development. Canola, sunflower, soybean and safflower are the main cultivated oilseeds in Iran. Soybean production in Iran is very low as compared to other countries. One of the most effective factor in increasing the soybean yield is seed inoculation with plant growth promoting rhizobacteria (PGPR and application of Zinc fertilizer. Some of the benefits provided by PGPR are the ability to produce gibberellic acid, cytokinins and ethylene, N2 fixation, solubilization of mineral phosphates and other nutrients (56. Numerous studies have shown a substantial increase in dry matter accumulation and seed yield following inoculation with PGPR. Seyed Sharifi (45 reported that seed inoculation with Azotobacter chroococcum strain 5 increased all of the growth indices such as total dry matter, crop growth rate and relative growth rate. Increasing and extending the role of biofertilizers such as Rhizobium can reduce the need for chemical fertilizers and decrease adverse environmental effects. Therefore, in the development and implementation of sustainable agricultural techniques, biofertilization has great importance in alleviating environmental pollution and deterioration of the nature. As a legume, soybean can obtain a significant portion (4-85% of its nitrogen requirement through symbiotic N2 fixation when grown in association with effective and compatible Rhizobium strains. Since there is little available information on nano-zinc oxide and seed inoculation by plant growth promoting rhizobacteria (PGPR on yield in the agro-ecological growing zones of Ardabil province of Iran. Therefore, this research was conducted to investigate the effects of nano-zinc oxide and seed inoculation with plant growth

  3. Genome sequence of the pattern forming Paenibacillus vortex bacterium reveals potential for thriving in complex environments

    NARCIS (Netherlands)

    Sirota-Madi, A.; Olender, T.; Helman, Y.; Ingham, C.; Brainis, I.; Roth, D.; Hagi, E.; Brodsky, L.; Leshkowitz, D.; Galatenko, V.; Nikolaev, V.; Mugasimangalam, R.C.; Bransburg-Zabary, S.; Gutnick, D.L.; Lancet, D.; Ben-Jacob, E.

    2010-01-01

    Background: The pattern-forming bacterium Paenibacillus vortex is notable for its advanced social behavior, which is reflected in development of colonies with highly intricate architectures. Prior to this study, only two other Paenibacillus species (Paenibacillus sp. JDR-2 and Paenibacillus larvae)

  4. Population densities of indigenous Acidobacteria change in the presence of plant growth promoting rhizobacteria (PGPR) in rhizosphere.

    Science.gov (United States)

    Kalam, Sadaf; Das, Subha Narayan; Basu, Anirban; Podile, Appa Rao

    2017-05-01

    Rhizosphere microbial community has diverse metabolic capabilities and plays a crucial role in maintaining plant health. Oligotrophic plant growth promoting rhizobacteria (PGPR), along with difficult-to-culture microbial fractions, might be involved synergistically in microbe-microbe and plant-microbe interactions in the rhizosphere. Among the difficult-to-culture microbial fractions, Acidobacteria constitutes the most dominant phylum thriving in rhizospheric soils. We selected effective PGPR for tomato and black gram and studied their effect on population densities of acidobacterial members. Three facultatively oligotrophic PGPR were identified through 16S rRNA gene sequencing as Sphingobacterium sp. (P3), Variovorax sp. (P4), and Roseomonas sp. (A2); the latter being a new report of PGPR. In presence of selected PGPR strains, the changes in population densities of Acidobacteria were monitored in metagenomic DNA extracted from bulk and rhizospheric soils of tomato and black gram using real time qPCR. A gradual increase in equivalent cell numbers of Acidobacteria members was observed over time along with a simultaneous increase in plant growth promotion by test PGPR. We report characterization of three effective PGPR strains and their effects on indigenous, underexplored difficult-to-culture phylum-Acidobacteria. We suggest that putative interactions between these two bacterial groups thriving in rhizospheric soils could be beneficial for plant growth. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. N2-fixation and seedling growth promotion of lodgepole pine by endophytic Paenibacillus polymyxa.

    Science.gov (United States)

    Anand, Richa; Grayston, Susan; Chanway, Christopher

    2013-08-01

    We inoculated lodgepole pine (Pinus contorta var. latifolia (Dougl.) Engelm.) with Paenibacillus polymyxa P2b-2R, a diazotrophic bacterium previously isolated from internal stem tissue of a naturally regenerating pine seedling to evaluate biological nitrogen fixation and seedling growth promotion by this microorganism. Seedlings generated from pine seed inoculated with strain P2b-2R were grown for up to 13 months in a N-limited soil mix containing 0.7 mM available N labeled as Ca((15)NO3)2 to facilitate detection of N2-fixation. Strain P2b-2R developed a persistent endophytic population comprising 10(2)-10(6) cfu g(-1) plant tissue inside pine roots, stems, and needles during the experiment. At the end of the growth period, P2b-2R had reduced seedling mortality by 14 % and (15)N foliar N abundance 79 % and doubled foliar N concentration and seedling biomass compared to controls. Our results suggest that N2-fixation by P. polymyxa enhanced growth of pine seedlings and support the hypothesis that plant-associated diazotrophs capable of endophytic colonization can satisfy a significant proportion of the N required by tree seedlings growing under N-limited conditions.

  6. Physiological and biochemical characterization of Azospirillum brasilense strains commonly used as plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Di Salvo, Luciana P; Silva, Esdras; Teixeira, Kátia R S; Cote, Rosalba Esquivel; Pereyra, M Alejandra; García de Salamone, Inés E

    2014-12-01

    Azospirillum is a plant growth-promoting rhizobacteria (PGPR) genus vastly studied and utilized as agriculture inoculants. Isolation of new strains under different environmental conditions allows the access to the genetic diversity and improves the success of inoculation procedures. Historically, the isolation of this genus has been performed by the use of some traditional culture media. In this work we characterized the physiology and biochemistry of five different A. brasilense strains, commonly used as cereal inoculants. The aim of this work is to contribute to pose into revision some concepts concerning the most used protocols to isolate and characterize this bacterium. We characterized their growth in different traditional and non-traditional culture media, evaluated some PGPR mechanisms and characterized their profiles of fatty acid methyl esters and carbon-source utilization. This work shows, for the first time, differences in both profiles, and ACC deaminase activity of A. brasilense strains. Also, we show unexpected results obtained in some of the evaluated culture media. Results obtained here and an exhaustive knowledge revision revealed that it is not appropriate to conclude about bacterial species without analyzing several strains. Also, it is necessary to continue developing studies and laboratory techniques to improve the isolation and characterization protocols. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Effects of water stress and inoculation with plant growth promoting rhizobacteria (PGPR on antioxidant status and photosynthetic pigments in basil (Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    Mostafa Heidari

    2012-01-01

    Full Text Available Effects of water stress and inoculation with plant growth promoting rhizobacteria (PGPR on antioxidant activity and photosynthetic pigments were studied in basil plants. A field experiment was conducted at the University of Zabol in Iran during 2010 growing season. The experiment laid out as split plot based on randomized complete block design with three replications. Three levels of water stress W1 = 80 (control, W2 = 60 and W3 = 40% of the field capacity (FC as main plots and four levels of bacterial species consisting of S1 = Pseudomonades sp., S2 = Bacillus lentus, S3 = Azospirillum brasilens, S4 = combination of three bacterial species and S5 = control (without use of bacterial as sub plots. The results revealed that water stress caused a significant change in the antioxidant activity. The highest concentration CAT and GPX activity were in W3 treatments. By increasing water stress from control to W3, chlorophyll content in leaves was increased but Fv/Fm and APX activity decreased. Application of rhizobacteria under water stress improved the antioxidant and photosynthetic pigments in basil plants. S1 = Pseudomonades sp. under water stress, significantly increased the CAT enzyme activity, but the highest GPX and APX activity and chlorophyll content in leaves under water stress were in S4 = combination of three bacterial species.

  8. Study on rhizobium interaction with osmoprotectant rhizobacteria for improving mung bean yield

    Science.gov (United States)

    Maryani, Y.; Sudadi; Dewi, W. S.; Yunus, A.

    2018-03-01

    Gunungkidul has calcareous soil with limitations including calcareous stone, mostly hilly terrain, and shallow cultivated layer. Furthermore, nowadays we face the disadvantages climates such as long dry seasons, a short rainy season and high temperatures caused by climate change. Climate change leads to irregular rainwater availability for microbes and crops. Research in this field is currently needed as climate change affected directly on crop production, while we need to find the strategy to keep high productivity of the plant. This research aimed to determine the ability of osmoprotectant rhizobacteria and rhizobium to support mung bean yield. Osmoprotectant rhizobacteria were isolated and screened from the calcareous soil in Gunungkidul with disadvantageous climates such as a long dry season, a short rainy season and high temperature. This research was arranged in Completely Randomized Design. The result showed that osmoprotectant rhizobacteria isolate of strain Al24-k and Ver5-k can produce 9.6306 mg g‑1 cell of glycine betaine in a soil density 1.7667 x 107 CFU g‑1 and 11.4870 mg g‑1 cell of glycine betaine in a soil density 1.9667 x 107 CFU g‑1. Inoculation of isolates osmoprotectant rhizobacteria can support mung bean yield. Osmoprotectant rhizobacteria isolate did not effect rhizobium in mung bean rhizosphere.

  9. Characterization of Rhizobacteria from field grown Genetically Modified (GM and non-GM maizes

    Directory of Open Access Journals (Sweden)

    Emmanuel Wihkochombom Bumunang

    2014-02-01

    Full Text Available This study was done to examine the rhizobacteria from field grown Genetically Modified (GM maize and its non-GM counterpart. Rhizospheric soil samples were collected at 30 days after sowing (DAS and at post-harvest from two experimental fields in Gauteng, South Africa. Total rhizobacteria (cfu/g in GM and non-GM soil samples was not significantly different across the different media 30 DAS and at post-harvest. Rhizobacterial isolates obtained were biochemically characterized using the analytical profile index. Species of Pseudomonas, Aeromonas, Sphingomonas, Burkholderia, Stenotrophomonas, Achromobacter, Ewingella and Bacillus were screened in vitro for plant growth promoting traits such as, ammonia production, catalase activity, indole acetic acid production, phosphate solubilisation, hydrogen cyanide production and antifungal activity. All the 32 rhizobacterial strains tested in this study were positive for catalase activity, ammonia production and IAA production; 90.6% were positive for phosphate solubilisation, 34.3% for indicate antifungal activity but none for hydrogen cyanide production. These findings contributed to the quest for potential biofertilizers and biocontrol agents for sustainable agriculture.

  10. Paenibacillus nebraskensis sp. nov., isolated from the root surface of field-grown maize.

    Science.gov (United States)

    Kämpfer, Peter; Busse, Hans-Jürgen; McInroy, John A; Hu, Chia-Hui; Kloepper, Joseph W; Glaeser, Stefanie P

    2017-12-01

    A Gram-positive-staining, aerobic, non-endospore-forming bacterial strain (JJ-59 T ), isolated from a field-grown maize plant in Dunbar, Nebraska in 2014 was studied by a polyphasic approach. Based on 16S rRNA gene sequence similarity comparisons, strain JJ-59 T was shown to be a member of the genus Paenibacillus, most closely related to the type strains of Paenibacillus aceris (98.6 % 16S rRNA gene sequence similarity) and Paenibacillus chondroitinus (97.8 %). For all other type strains of species of the genus Paenibacillus lower 16S rRNA gene sequence similarities were obtained. DNA-DNA hybridization values of strain JJ-59 T to the type strains of P. aceris and P. chondroitinus were 26 % (reciprocal, 59 %) and 52 % (reciprocal, 59 %), respectively. Chemotaxonomic characteristics such as the presence of meso-diaminopimelic acid in the peptidoglycan, the major quinone MK-7 and spermidine as the major polyamine were in agreement with the characteristics of the genus Paenibacillus. Strain JJ-59 T shared with its next related species P. aceris the major lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminophospholipid, but the presence/absence of certain lipids was clearly distinguishable. Major fatty acids of strain JJ-59 T were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0, and the genomic G+C content is 47.2 mol%. Physiological and biochemical characteristics of strain JJ-59 T were clearly different from the most closely related species of the genus Paenibacillus. Thus, strain JJ-59 T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus nebraskensis sp. nov. is proposed, with JJ-59 T (=DSM 103623 T =CIP 111179 T =LMG 29764 T ) as the type strain.

  11. SCREENING OF FLUORESCENT RHIZOBACTERIA FOR THE BIOCONTROL OF SOILBORNE PLANT PATHOGENIC FUNGI

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    ANELISE DIAS

    2014-01-01

    Full Text Available The biocontrol of soilborne plant pathogens represents a promising approach from the environ- mental and practical points of view. Fluorescent pseudomonad rhizobacteria are well known by their antagonis- tic capacity towards several plant pathogens due to a diversity of antimicrobial metabolites they produce. This study was conceived to select and characterize rhizobacteria having antagonistic potential towards the patho- genic fungi Rhizoctonia solani and Sclerotium rolfsii. A total of 94 bacterial strains isolated from the rhizospheres of four vegetable species under organic cultivation were evaluated. Twenty-two strains which predominate in lettuce and rudbeckia rhizospheres showed identical biochemical profiles to Pseudomonas fluo- rescens, while in kale and parsley rhizospheres identical profiles to Pseudomonas putida (subgroups A and B strains prevailed. Two types of antagonism were verified in vitro and defined as competition and inhibition of mycelial growth. Sixty percent of the evaluated strains showed antagonistic potential and, among those, 24 strains expressed antagonism to both target fungi, with P. fluorescens being the most representative bacterial species. This work clearly identified a number of strains with potential for use as plant growth-promoting and biocontrol of the two soilborne fungal pathogens in vegetable crops production systems.

  12. Inoculation of Schizolobium parahyba with mycorrhizal fungi and plant growth-promoting rhizobacteria increases wood yield under field conditions

    Directory of Open Access Journals (Sweden)

    Martha Viviana Torres Cely

    2016-11-01

    Full Text Available Schizolobium parahyba var. amazonicum (Huber ex Ducke occurs naturally in the Brazilian Amazon. Currently, it is being planted extensively because of its fast growth and excellent use in forestry. Consequently, there is great interest in new strategies to increase wood production. The interaction between soil microorganisms and plants, specifically in the roots, provides essential nutrients for plant growth. These interactions can have growth-promoting effects. In this way, this study assessed the effect of the inoculation with arbuscular mycorrhizal fungi (AMF and plant growth-promoting rhizobacteria (PGPR on growth of S. parahyba var. amazonicum under field conditions. We used two native species of arbuscular mycorrhizal fungi, Claroideoglomus etunicatum (Ce and Acaulospora sp. (Ac; two native strains of Rhizobium sp. (Rh1 and Rh2; and a non-native strain of Burkholderia sp. Different combinations of microorganisms were supplemented with chemical fertilizers (doses D1 and D2 in two planting methods, seed sowing and seedling planting. In seed sowing, the results showed that treatments with Ce/Rh1/Fertilizer D2 and Ac/No PGPR/Fertilizer D2 increased wood yield. In seedling planting, two combinations (Ac/Rh2/Fertilizer D1 and Ac/Rh1/Fertilizer D1 were more effective in increasing seedling growth. In these experiments, inoculation with AMF and PGPR increased wood yield by about 20% compared to the application of fertilizer alone.

  13. Inoculation of Schizolobium parahyba with Mycorrhizal Fungi and Plant Growth-Promoting Rhizobacteria Increases Wood Yield under Field Conditions.

    Science.gov (United States)

    Cely, Martha V T; Siviero, Marco A; Emiliano, Janaina; Spago, Flávia R; Freitas, Vanessa F; Barazetti, André R; Goya, Erika T; Lamberti, Gustavo de Souza; Dos Santos, Igor M O; De Oliveira, Admilton G; Andrade, Galdino

    2016-01-01

    Schizolobium parahyba var. amazonicum (Huber ex Ducke) occurs naturally in the Brazilian Amazon. Currently, it is being planted extensively because of its fast growth and excellent use in forestry. Consequently, there is great interest in new strategies to increase wood production. The interaction between soil microorganisms and plants, specifically in the roots, provides essential nutrients for plant growth. These interactions can have growth-promoting effects. In this way, this study assessed the effect of the inoculation with arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on growth of S. parahyba var. amazonicum under field conditions. We used two native species of arbuscular mycorrhizal fungi, Claroideoglomus etunicatum (Ce), and Acaulospora sp. (Ac); two native strains of Rhizobium sp. (Rh1 and Rh2); and a non-native strain of Burkholderia sp. Different combinations of microorganisms were supplemented with chemical fertilizers (doses D1 and D2) in two planting methods, seed sowing and seedling planting. In seed sowing, the results showed that treatments with Ce/Rh1/Fertilizer D2 and Ac/No PGPR/Fertilizer D2 increased wood yield. In seedling planting, two combinations (Ac/Rh2/Fertilizer D1 and Ac/Rh1/Fertilizer D1) were more effective in increasing seedling growth. In these experiments, inoculation with AMF and PGPR increased wood yield by about 20% compared to the application of fertilizer alone.

  14. Draft genome sequence of an endophytic bacterium, Paenibacillus tyrfis strain SUK123, isolated from Santiria apiculata stem

    Directory of Open Access Journals (Sweden)

    Emmanuel Haruna

    2017-12-01

    Full Text Available Here we report the draft genome sequence of an endophytic Paenibacillus tyrfis strain isolated from the Universiti Kebangsaan Malaysia reserve forest, Malaysia. The genome size was approximately 8.04 Mb, and the assembly consisted of 107 scaffolds with 168 contigs, and had a G + C content of 53%. Phylogenetic analysis of strain SUK123 using the 16S rRNA gene revealed that it belonged to the family Paenibacillaceae with the highest similarity to Paenibacillus elgii SDT (99%. Whole genome comparison of SUK123 with related species using average nucleotide identity (ANI analysis revealed a similarity of 98% to Paenibacillus tyrfis Mst1T, 94% to Paenibacillus elgii B69T, 91% to Paenibacillus ehimensis A2T, 68% to Paenibacillus polymyxa SC2T and 69% to Paenibacillus alvei DMS29T. The draft genome was deposited at the European Nucleotide Archive (PRJEB21373.

  15. Variation in plant-mediated interactions between rhizobacteria and caterpillars: potential role of soil composition

    NARCIS (Netherlands)

    Pangesti, N.P.D.; Pineda Gomez, A.M.; Dicke, M.; Loon, van J.J.A.

    2015-01-01

    Selected strains of non-pathogenic rhizobacteria can trigger induced systemic resistance (ISR) in plants against aboveground insect herbivores. However, the underlying mechanisms of plant-mediated interactions between rhizobacteria and herbivorous insects are still poorly understood. Using

  16. Paenibacillus lentimorbus Inoculation Enhances Tobacco Growth and Extenuates the Virulence of Cucumber mosaic virus.

    Directory of Open Access Journals (Sweden)

    Susheel Kumar

    Full Text Available Previous studies with Paenibacillus lentimorbus B-30488" (hereafter referred as B-30488, a plant growth promoting rhizobacteria (PGPR isolated from cow's milk, revealed its capabilities to improve plant quality under normal and stress conditions. Present study investigates its potential as a biocontrol agent against an economically important virus, Cucumber mosaic virus (CMV, in Nicotiana tabacum cv. White Burley plants and delineates the physical, biophysical, biochemical and molecular perturbations due to the trilateral interactions of PGPR-host-CMV. Soil inoculation of B-30488 enhanced the plant vigor while significantly decreased the virulence and virus RNA accumulation by ~12 fold (91% in systemic leaves of CMV infected tobacco plants as compared to the control ones. Histology of these leaves revealed the improved tissue's health and least aging signs in B-30488 inoculated tobacco plants, with or without CMV infection, and showed lesser intercellular spaces between collenchyma cells, reduced amount of xyloglucans and pectins in connecting primary cells, and higher polyphenol accumulation in hypodermis layer extending to collenchyma cells. B-30488 inoculation has favorably maneuvered the essential biophysical (ion leakage and photosynthetic efficiency and biochemical (sugar, proline, chlorophyll, malondialdehyde, acid phosphatase and alkaline phosphatase attributes of tobacco plants to positively regulate and release the virus stress. Moreover, activities of defense related enzymes (ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase and catalase induced due to CMV-infection were ameliorated with inoculation of B-30488, suggesting systemic induced resistance mediated protection against CMV in tobacco. The quantitative RT-PCR analyses of the genes related to normal plant development, stress and pathogenesis also corroborate well with the biochemical data and revealed the regulation (either up or down of these genes in favor of

  17. Laboratory study on influence of plant growth promoting ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-03-06

    Mar 6, 2015 ... promoting rhizobacteria (PGPR) on growth response and tolerance of Zea ... inoculating maize seeds with plant growth promoting rhizobacterial strains in a crude oil impacted medium. ..... Botany and Environmental Health.

  18. ACC deaminase and IAA producing growth promoting bacteria from the rhizosphere soil of tropical rice plants.

    Science.gov (United States)

    Bal, Himadri Bhusan; Das, Subhasis; Dangar, Tushar K; Adhya, Tapan K

    2013-12-01

    Beneficial plant-associated bacteria play a key role in supporting and/or promoting plant growth and health. Plant growth promoting bacteria present in the rhizosphere of crop plants can directly affect plant metabolism or modulate phytohormone production or degradation. We isolated 355 bacteria from the rhizosphere of rice plants grown in the farmers' fields in the coastal rice field soil from five different locations of the Ganjam district of Odisha, India. Six bacteria producing both ACC deaminase (ranging from 603.94 to 1350.02 nmol α-ketobutyrate mg(-1)  h(-1) ) and indole acetic acid (IAA; ranging from 10.54 to 37.65 μM ml(-1) ) in pure cultures were further identified using polyphasic taxonomy including BIOLOG((R)) , FAME analysis and the 16S rRNA gene sequencing. Phylogenetic analyses of the isolates resulted into five major clusters to include members of the genera Bacillus, Microbacterium, Methylophaga, Agromyces, and Paenibacillus. Seed inoculation of rice (cv. Naveen) by the six individual PGPR isolates had a considerable impact on different growth parameters including root elongation that was positively correlated with ACC deaminase activity and IAA production. The cultures also had other plant growth attributes including ammonia production and at least two isolates produced siderophores. Study indicates that presence of diverse rhizobacteria with effective growth-promoting traits, in the rice rhizosphere, may be exploited for a sustainable crop management under field conditions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Prevalence of American Foulbrood and Paenibacillus Larvae Genotypes in Bulgaria

    OpenAIRE

    RUSENOVA, Nikolina; PARVANOV, Parvan

    2016-01-01

    This study aimed to analyse the prevalence of American foulbrood and Paenibacillus larvae genotypes in Bulgaria. For this purpose, data concerning American foulbrood outbreaks were used. Also, available data on the number of destroyed bee families covering a twenty-five-year period (1989 - 2013) was collected from the register of Bulgarian Food Safety Agency. In addition, Paenibacillus larvae genotypes in 15 apiaries were established by rep - PCR with BOXA1R and MBOREP1 primers. Results showe...

  20. Noncontiguous finished genome sequence and description of Paenibacillus antibioticophila sp. nov. GD11T, the type strain of Paenibacillus antibioticophila

    Directory of Open Access Journals (Sweden)

    G. Dubourg

    2015-11-01

    Full Text Available Paenibacillus antibioticophila strain GD11T sp. nov. is the type strain of a new species within the genus Paenibacillus. This strain, whose genome is described here, was isolated from human faeces of a 63-year-old woman with multidrug-resistant tuberculosis who was receiving numerous antibiotics at the time of stool collection. P. antibioticophila is a Gram-positive aerobic bacterium. We describe here the features of this bacterium, together with the complete genome sequence and annotation. The 5 562 631 bp long genome contains 5084 protein-coding and 71 RNA genes.

  1. Study on osmoprotectant rhizobacteria to improve mung bean growth under drought stress

    Science.gov (United States)

    Maryani, Y.; Sudadi; Dewi, W. S.; Yunus, A.

    2018-03-01

    Climate change leads to irregular rainwater availability for crops and thus enhances drought stress. Furthermore, nowadays we face climate disadvantages such as long dry season, short rainy season and high air temperature caused by climate change. This research aimed at studying the ability of osmoprotectant rhizobacteria isolates to support mung bean growth under drought stress. The rhizobacteria were isolated from mung bean’s rhizosphere. The results showed that isolates of strain Al24-k and Ver5-k produced glycine betaine 9.6306 mg g‑1 cell, 1.7667 x 107 CFU g‑1 soil and 11.4870 mg g”1 cell, 1.9667 x 107 CFU g‑1 soil. The isolated rhizobacteria from mung bean’s rhizosphere under field capacity of soil moisture produced glycine betaine 6.8000 mg g‑1 cell, 1.2556 x 107 CFU g‑1 soil. Under 75% field capacity of soil moisture, isolates produced glycine betaine of 6.4059 mg g‑1 cell, 1.3111 x 107 CFU g‑1 soil, while under 50% from field capacity, the isolates produced glycine betaine of 7.4108 mg g‑1 cell, 1.6667 x 107 CFU g‑1 soil. The osmoprotectant rhizobacteria improved the resilience of mung bean to drought stress.

  2. The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

    Science.gov (United States)

    Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

    2009-04-01

    Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress.

  3. Real-time PCR detection of Paenibacillus spp. in raw milk to predict shelf life performance of pasteurized fluid milk products.

    Science.gov (United States)

    Ranieri, Matthew L; Ivy, Reid A; Mitchell, W Robert; Call, Emma; Masiello, Stephanie N; Wiedmann, Martin; Boor, Kathryn J

    2012-08-01

    Psychrotolerant sporeformers, specifically Paenibacillus spp., are important spoilage bacteria for pasteurized, refrigerated foods such as fluid milk. While Paenibacillus spp. have been isolated from farm environments, raw milk, processing plant environments, and pasteurized fluid milk, no information on the number of Paenibacillus spp. that need to be present in raw milk to cause pasteurized milk spoilage was available. A real-time PCR assay targeting the 16S rRNA gene was designed to detect Paenibacillus spp. in fluid milk and to discriminate between Paenibacillus and other closely related spore-forming bacteria. Specificity was confirmed using 16 Paenibacillus and 17 Bacillus isolates. All 16 Paenibacillus isolates were detected with a mean cycle threshold (C(T)) of 19.14 ± 0.54. While 14/17 Bacillus isolates showed no signal (C(T) > 40), 3 Bacillus isolates showed very weak positive signals (C(T) = 38.66 ± 0.65). The assay provided a detection limit of approximately 3.25 × 10(1) CFU/ml using total genomic DNA extracted from raw milk samples inoculated with Paenibacillus. Application of the TaqMan PCR to colony lysates obtained from heat-treated and enriched raw milk provided fast and accurate detection of Paenibacillus. Heat-treated milk samples where Paenibacillus (≥1 CFU/ml) was detected by this colony TaqMan PCR showed high bacterial counts (>4.30 log CFU/ml) after refrigerated storage (6°C) for 21 days. We thus developed a tool for rapid detection of Paenibacillus that has the potential to identify raw milk with microbial spoilage potential as a pasteurized product.

  4. Co-inoculation with Rhizobium and plant growth promoting rhizobacteria (PGPR for inducing salinity tolerance in mung bean under field condition of semi arid climate

    Directory of Open Access Journals (Sweden)

    Muhammad Aamir

    2013-04-01

    Full Text Available Salinity stress severely affects the growth, nodulation and yield of mung bean (Vigna radiata L.. However, its growth can be improved under salinity stress by inoculation/co-inoculation with rhizobia and plant growth promoting rhizobacteria (PGPR containing 1-Aminocyclopropane-1-carboxylic acid (ACC deaminase enzyme. ACC-deaminase containing bacteria regulate the stress induced ethylene production by hydrolyzing the ACC (immediate precursor of ethylene into ammonia and ketobutyric acid, thus improve plant growth by lowering the ethylene level. A study was conducted under salt affected field conditions where pre-isolated strains of Rhizobium and PGPR were used alone as well as in combination for mitigating the salinity stress on growth, nodulation and yield of mung bean by following the randomized complete block design (RCBD. The data were recorded and analyzed statistically to see the difference among treatments.

  5. Biological control of Heterodera glycines by spore-forming plant growth-promoting rhizobacteria (PGPR on soybean.

    Directory of Open Access Journals (Sweden)

    Ni Xiang

    Full Text Available Heterodera glycines, the soybean cyst nematode, is the most economically important plant-parasitic nematode on soybean production in the U.S. The objectives of this study were to evaluate the potential of plant growth-promoting rhizobacteria (PGPR strains for mortality of H. glycines J2 in vitro and for reducing nematode population density on soybean in greenhouse, microplot, and field trials. The major group causing mortality to H. glycines in vitro was the genus Bacillus that consisted of 92.6% of the total 663 PGPR strains evaluated. The subsequent greenhouse, microplot, and field trials indicated that B. velezensis strain Bve2 consistently reduced H. glycines cyst population density at 60 DAP. Bacillus mojavensis strain Bmo3 suppressed H. glycines cyst and total H. glycines population density under greenhouse conditions. Bacillus safensis strain Bsa27 and Mixture 1 (Bve2 + Bal13 reduced H. glycines cyst population density at 60 DAP in the field trials. Bacillus subtilis subsp. subtilis strains Bsssu2 and Bsssu3, and B. velezensis strain Bve12 increased early soybean growth including plant height and plant biomass in the greenhouse trials. Bacillus altitudinis strain Bal13 increased early plant growth on soybean in the greenhouse and microplot trials. Mixture 2 (Abamectin + Bve2 + Bal13 increased early plant growth in the microplot trials at 60 DAP, and also enhanced soybean yield at harvest in the field trials. These results demonstrated that individual PGPR strains and mixtures can reduce H. glycines population density in the greenhouse, microplot, and field conditions, and increased yield of soybean.

  6. Biological control of Heterodera glycines by spore-forming plant growth-promoting rhizobacteria (PGPR) on soybean.

    Science.gov (United States)

    Xiang, Ni; Lawrence, Kathy S; Kloepper, Joseph W; Donald, Patricia A; McInroy, John A

    2017-01-01

    Heterodera glycines, the soybean cyst nematode, is the most economically important plant-parasitic nematode on soybean production in the U.S. The objectives of this study were to evaluate the potential of plant growth-promoting rhizobacteria (PGPR) strains for mortality of H. glycines J2 in vitro and for reducing nematode population density on soybean in greenhouse, microplot, and field trials. The major group causing mortality to H. glycines in vitro was the genus Bacillus that consisted of 92.6% of the total 663 PGPR strains evaluated. The subsequent greenhouse, microplot, and field trials indicated that B. velezensis strain Bve2 consistently reduced H. glycines cyst population density at 60 DAP. Bacillus mojavensis strain Bmo3 suppressed H. glycines cyst and total H. glycines population density under greenhouse conditions. Bacillus safensis strain Bsa27 and Mixture 1 (Bve2 + Bal13) reduced H. glycines cyst population density at 60 DAP in the field trials. Bacillus subtilis subsp. subtilis strains Bsssu2 and Bsssu3, and B. velezensis strain Bve12 increased early soybean growth including plant height and plant biomass in the greenhouse trials. Bacillus altitudinis strain Bal13 increased early plant growth on soybean in the greenhouse and microplot trials. Mixture 2 (Abamectin + Bve2 + Bal13) increased early plant growth in the microplot trials at 60 DAP, and also enhanced soybean yield at harvest in the field trials. These results demonstrated that individual PGPR strains and mixtures can reduce H. glycines population density in the greenhouse, microplot, and field conditions, and increased yield of soybean.

  7. Novel pyrazine metabolites found in polymyxin biosynthesis by Paenibacillus polymyxa

    DEFF Research Database (Denmark)

    Beck, Hans Christian; Hansen, Anne M; Lauritsen, Frants R

    2003-01-01

    A complex mixture of methyl-branched alkyl-substituted pyrazines was found in the growth medium of the polymyxin-producing bacterium Paenibacillus polymyxa, and of these, seven are new natural compounds. A total of 19 pyrazine metabolites were identified. The dominant metabolite was 2,5-diisoprop......A complex mixture of methyl-branched alkyl-substituted pyrazines was found in the growth medium of the polymyxin-producing bacterium Paenibacillus polymyxa, and of these, seven are new natural compounds. A total of 19 pyrazine metabolites were identified. The dominant metabolite was 2...

  8. Isolation, identification and characterization of Paenibacillus polymyxa CR1 with potentials for biopesticide, biofertilization, biomass degradation and biofuel production

    OpenAIRE

    Weselowski, Brian; Nathoo, Naeem; Eastman, Alexander William; MacDonald, Jacqueline; Yuan, Ze-Chun

    2016-01-01

    Background Paenibacillus polymyxa is a plant-growth promoting rhizobacterium that could be exploited as an environmentally friendlier alternative to chemical fertilizers and pesticides. Various strains have been isolated that can benefit agriculture through antimicrobial activity, nitrogen fixation, phosphate solubilization, plant hormone production, or lignocellulose degradation. However, no single strain has yet been identified in which all of these advantageous traits have been confirmed. ...

  9. Bioremediation of petroleum contaminated soil to combat toxicity on Withania somnifera through seed priming with biosurfactant producing plant growth promoting rhizobacteria.

    Science.gov (United States)

    Das, Amar Jyoti; Kumar, Rajesh

    2016-06-01

    Soil contaminated by Petroleum oil cannot be utilized for agricultural purposes due to hydrocarbon toxicity. Oil contaminated soil induces toxicity affecting germination, growth and productivity. Several technologies have been proposed for bioremediation of oil contaminated sites, but remediation through biosurfactant producing plant growth promontory rhizobacteria (PGPR) is considered to be most promising methods. In the present study the efficacy of seed priming on growth and pigment of Withania somnifera under petroleum toxicity is explored. Seeds of W. somnifera were primed with biosurfactant producing Pseudomonas sp. AJ15 with plant growth promoting traits having potentiality to utilized petroleum as carbon source. Results indicates that plant arose from priming seeds under various petroleum concentration expressed high values for all the parameters studied namely germination, shoot length, root length, fresh and dry weight and pigments (chlorophyll and carotenoid) as compared to non primed seed. Hence, the present study signifies that petroleum degrarding biosurfactant producing PGPR could be further used for management and detoxification of petroleum contaminated soils for growing economically important crops. Copyright © 2016. Published by Elsevier Ltd.

  10. Isolation, characterization, and evaluation of multi-trait plant growth promoting rhizobacteria for their growth promoting and disease suppressing effects on ginger.

    Science.gov (United States)

    Dinesh, Raghavan; Anandaraj, Muthuswamy; Kumar, Aundy; Bini, Yogiyar Kundil; Subila, Kizhakke Purayil; Aravind, Ravindran

    2015-04-01

    In this study, 100 PGPR strains isolated from different varieties of ginger (Zingiber officinale Rosc.) were first characterized for their morphological, biochemical, and nutrient mobilization traits in vitro. The PGPR were also screened in vitro for inhibition of Pythium myriotylum causing soft rot in ginger. Results revealed that only five PGPR showed >70% suppression of P. myriotylum. These 5 PGPR viz., GRB (Ginger rhizobacteria) 25--Burkholderia cepacia, GRB35--Bacillus amyloliquefaciens; GRB58--Serratia marcescens; GRB68--S. marcescens; GRB91--Pseudomonas aeruginosa were used for further growth promotion and biocontrol studies in the green house and field. The green house study revealed that GRB35 (B. amyloliquefaciens) and GRB68 (S. marcescens) registered markedly higher sprouting (96.3%) and lower disease incidence (48.1%) and greater rhizome yield (365.6 g pot(-1) and 384.4 g pot(-1), respectively), while control registered the lowest sprouting (66%), maximum soft rot incidence (100%) and lowest rhizome yield (134.4 g pot(-1)). In the field experiments also, GRB68 (S. marcescens) and GRB35 (B. amyloliquefaciens) registered the greatest sprouting (80% each), markedly lower soft rot incidence (5.2% and 7.3%, respectively) and higher yield (5.0 and 4.3 kg(3)m(-2), respectively) compared to chemicals like Streptomycin sulphate (73.0%, 18.5% and 2.3 kg(3)m(-2), respectively), Metalaxyl-Mancozeb (73.0%, 14.0% and 3.8 kg(3)m(-2), respectively) and control (73.0%, 25.1% and 2.2 kg 3m(-2), respectively). Overall, the results suggested that for growth promotion and management of soft rot disease in ginger, GRB35 B. amyloliquefaciens and GRB68 S. marcescens could be good alternatives to chemical measures. Since, the latter has been reported to be an opportunistic human pathogen, we recommend the use of B. amyloliquefaciens for integration into nutrient and disease management schedules for ginger cultivation. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. Cytokinin-producing, plant growth-promoting rhizobacteria that confer resistance to drought stress in Platycladus orientalis container seedlings.

    Science.gov (United States)

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-10-01

    One of the proposed mechanisms through which plant growth-promoting rhizobacteria (PGPR) enhance plant growth is the production of plant growth regulators, especially cytokinin. However, little information is available regarding cytokinin-producing PGPR inoculation on growth and water stress consistence of forest container seedlings under drought condition. This study determined the effects of Bacillus subtilis on hormone concentration, drought resistance, and plant growth under water-stressed conditions. Although no significant difference was observed under well-watered conditions, leaves of inoculated Platycladus orientalis (oriental thuja) seedlings under drought stress had higher relative water content and leaf water potential compared with those of noninoculated ones. Regardless of water supply levels, the root exudates, namely sugars, amino acids and organic acids, significantly increased because of B. subtilis inoculation. Water stress reduced shoot cytokinins by 39.14 %. However, inoculation decreased this deficit to only 10.22 %. The elevated levels of cytokinins in P. orientalis shoot were associated with higher concentration of abscisic acid (ABA). Stomatal conductance was significantly increased by B. subtilis inoculation in well-watered seedlings. However, the promoting effect of cytokinins on stomatal conductance was hampered, possibly by the combined action of elevated cytokinins and ABA. B. subtilis inoculation increased the shoot dry weight of well-watered and drought seedlings by 34.85 and 19.23 %, as well as the root by 15.445 and 13.99 %, respectively. Consequently, the root/shoot ratio significantly decreased, indicative of the greater benefits of PGPR on shoot growth than root. Thus, inoculation of cytokinin-producing PGPR in container seedlings can alleviate the drought stress and interfere with the suppression of shoot growth, showing a real potential to perform as a drought stress inhibitor in arid environments.

  12. Paenibacillus aceris sp. nov., isolated from the rhizosphere of Acer okamotoanum, a plant native to Ulleungdo Island, Republic of Korea.

    Science.gov (United States)

    Hwang, Ye-Ji; Ghim, Sa-Youl

    2017-04-01

    Strain KUDC4121 T was isolated from the rhizosphere of Acer okamotoanum, a plant native to the Korean island of Ulleungdo. The strain was a Gram-stain-positive, non-spore-forming, non-motile, rod-shaped bacterium that can grow at 18-37 °C and pH 6.0-7.5, with optimum growth at 30 °C and pH 7.0. It grew on tryptic soy agar containing less than 0.5 % (w/v) NaCl and in R2A broth. Cell length ranged from 2.0 to 2.5 µm. Strain KUDC4121 T was oxidase- and catalase-positive and did not hydrolyse starch or casein. The genomic G+C content was 48.8 mol%. The major fatty acids were anteiso-C15 : 0 and iso-C16 : 0. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KUDC4121 T belongs to the genus Paenibacillus. The closest type strain was Paenibacillus chondroitinus DSM 5051 T , with 97.8 % similarity, followed by Paenibacillus alginolyticus DSM 5050 T (97.6 %), Paenibacillus ferrarius CY1 T (97.5 %), Paenibacillus pocheonensis Gsoil 1138 T (97.5 %), Paenibacillus frigoriresistens YIM 016 T (97.5 %), Paenibacillus pectinilyticus RCB-08 T (97.2 %) and Paenibacillus aestuarii CJ25 T (96.9 %). Based on its phenotypic properties and phylogenetic and genetic data, strain KUDC4121 T should be considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus aceris sp. nov. is proposed. The type strain is KUDC4121 T (=KCTC 13870 T =DSM 24950 T ).

  13. Paenibacillus motobuensis sp. nov., isolated from a composting machine utilizing soil from Motobu-town, Okinawa, Japan.

    Science.gov (United States)

    Iida, Ken-ichiro; Ueda, Yasuichi; Kawamura, Yoshiaki; Ezaki, Takayuki; Takade, Akemi; Yoshida, Shin-ichi; Amako, Kazunobu

    2005-09-01

    A novel bacterial strain, MC10(T), was isolated from a compost sample produced in a composting machine utilizing soil from Motobu-town, Okinawa, Japan. The isolate was Gram-negative, but produced endospores. These conflicting characters prompted a taxonomic study of the isolate. The isolate was examined using a combination of phenotypic characterization, cellular fatty acid analysis, DNA base composition determination and 16S rRNA gene sequence analysis. Phylogenetic analysis, based on 16S rRNA gene sequence comparisons, placed strain MC10(T) within the genus Paenibacillus. As in other Paenibacillus species, the isolate contained anteiso-C(15:0) as the major fatty acid and the DNA G+C content was 47.0 mol%. However, 16S rRNA gene sequence similarity values of less than 95.6% were found between this isolate and all members of the genus Paenibacillus. Based upon these results, strain MC10(T) (=GTC 1835(T)=JCM 12774(T)=CCUG 50090(T)) should be designated as the type strain of a novel species within the genus Paenibacillus, Paenibacillus motobuensis sp. nov.

  14. Identification and Pathogenic Potential of Clinical Bacillus and Paenibacillus Isolates.

    Directory of Open Access Journals (Sweden)

    Francesco Celandroni

    Full Text Available The soil-related Bacillus and Paenibacillus species have increasingly been implicated in various human diseases. Nevertheless, their identification still poses problems in the clinical microbiology laboratory and, with the exception of Bacillus anthracis and Bacillus cereus, little is known on their pathogenicity for humans. In this study, we evaluated the use of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS in the identification of clinical isolates of these genera and conducted genotypic and phenotypic analyses to highlight specific virulence properties. Seventy-five clinical isolates were subjected to biochemical and MALDI-TOF MS identification. 16S rDNA sequencing and supplemental tests were used to solve any discrepancies or failures in the identification results. MALDI-TOF MS significantly outperformed classical biochemical testing for correct species identification and no misidentification was obtained. One third of the collected strains belonged to the B. cereus species, but also Bacillus pumilus and Bacillus subtilis were isolated at high rate. Antimicrobial susceptibility testing showed that all the B. cereus, B. licheniformis, B. simplex, B. mycoides, Paenibacillus glucanolyticus and Paenibacillus lautus isolates are resistant to penicillin. The evaluation of toxin/enzyme secretion, toxin-encoding genes, motility, and biofilm formation revealed that B. cereus displays the highest virulence potential. However, although generally considered nonpathogenic, most of the other species were shown to swim, swarm, produce biofilms, and secrete proteases that can have a role in bacterial virulence. In conclusion, MALDI-TOF MS appears useful for fast and accurate identification of Bacillus and Paenibacillus strains whose virulence properties make them of increasing clinical relevance.

  15. Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola

    Directory of Open Access Journals (Sweden)

    Surender Kumar

    2013-11-01

    Full Text Available An experiment on the metabolite [salicylic acid (SA, jasmonicacid (JA, hydrocyanic acid (HCN and chitinase activity] changes owing to seed treatment with pathogen, plant growth promoting rhizobacteria (PGPRs - (P. maltophilia, P. fluorescens and Bacillus subtilis alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola treated seeds showed an initial increase in SA and hydrocyanic acid HCN content and an opposite trend was observed for JA level and chitinase activity. Though, PGPRs inoculation resulted in higher increase in SA level, JA level and chitinaseactivity in both the cases alone as well as in integration with pathogen, however, maximum increase in JA content was explicited in plants raised after seed treatment with P. fluorescens, the most effective rhizobacteria amongst PGPRs studied. Highest increase in HCN content (45 μg g-1 over control (24 μg g-1 was noticed for P. fluorescens followed by co-seed inoculation with P. fluorescens + pathogen (43 μg g-1 at 10 DPI. The co-seed inoculation elicited 68 units at 10 DPI whereas the pathogen challenged plants showed lower chitinase activity with 42 units. All the metabolites declinedslightly or sharply with age of the plant irrespective of inoculations.

  16. Draft Genome Sequence of the Efficient Bioflocculant-Producing Bacterium Paenibacillus sp. Strain A9

    Science.gov (United States)

    Liu, Jin-liang; Hu, Xiao-min

    2013-01-01

    Paenibacillus sp. strain A9 is an important bioflocculant-producing bacterium, isolated from a soil sample, and is pale pink-pigmented, aerobic, and Gram-positive. Here, we report the draft genome sequence and the initial findings from a preliminary analysis of strain A9, which is a novel species of Paenibacillus. PMID:23618713

  17. Potential of plant growth promoting rhizobacteria and chemical fertilizers on soil enzymes and plant growth

    International Nuclear Information System (INIS)

    Nosheen, A.; Bano, A.

    2014-01-01

    The present investigation deals with the role of Plant Growth Promoting Rhizobacteria and chemical fertilizers alone or in combination on urease, invertase and phosphatase activities of rhizospheric soil and also on general impact on growth of safflower cvv. Thori and Saif-32. The PGPR (Azospirillum brasilense and Azotobacter vinelandii) were applied at 10/sup 6/ cells/mL as seed inoculation prior to sowing. Chemical fertilizers were applied at full (Urea 60 Kg ha/sup -1/ and Diammonium phosphate (DAP) 30 Kg ha/sup -1/), half (Urea 30 Kg ha/sup -1/ and DAP 15 Kg ha/sup -1/) and quarter doses (Urea 15 Kg ha-1 and DAP 7.5 Kg ha/sup -1/) during sowing. The chemical fertilizers and PGPR enhanced urease and invertase activities of soil. Presence of PGPR in combination with quarter and half doses of chemical fertilizers further augmented their effect on soil enzymes activities. The soil phosphatase activity was greater in Azospirillum and Azotobacter in combination with half dose of chemical fertilizers. Maximum increase in leaf melondialdehyde content was recorded in full dose of chemical fertilizers whereas coinoculation treatment exhibited significant reduction in cv. Thori. Half and quarter dose of chemical fertilizers increased the shoot length of safflower whereas maximum increase in leaf protein was recorded in Azotobacter in combination with full dose of chemical fertilizers. Root length was improved by Azospirillum and Azotobacter in combination with quarter dose of chemical fertilizers. Leaf area and chlorophyll contents were significantly improved by Azotobacter in combination with half dose of chemical fertilizers. It is inferred that PGPR can supplement 50 % chemical fertilizers for better plant growth and soil health. (author)

  18. Severe Sepsis Secondary to Persistent Lysinibacillus sphaericus, Lysinibacillus fusiformis and Paenibacillus amylolyticus Bacteremia

    Directory of Open Access Journals (Sweden)

    Eric Wenzler

    2015-06-01

    Full Text Available Lysinibacillus and Paenibacillus are pervasive bacteria rarely associated with human disease. Less sophisticated microbiology techniques may frequently incorrectly identify these genera as Bacillus spp., often regarded as environmental contamination. This report describes a case of severe sepsis due to persistent Lysinibacillus and Paenibacillus bacteremia, identified by matrix-assisted laser desorption and ionization time-of-flight mass spectroscopy and 16S rRNA gene sequencing.

  19. Pectinase Production by Bacillus and Paenibacillus sp. Isolated from Decomposing Wood Residues in the Lagos Lagoon

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    Busayo Tosin Akinyemi

    2017-09-01

    Full Text Available Three wood decomposing bacteria isolated from the Lagos lagoon, Bacillus megaterium, Bacillus bataviensis and Paenibacillus sp. were screened for their pectinase producing abilities using pectin as substrate under submerged fermentation (SMF conditions. The results showed that all three isolates produced appreciable pectinolytic activities. Paenibacillus sp. showed the highest pectinase activity when compared with the other two isolates. The optimum pH for pectinase activity for both B. megaterium and B. bataviensis was 8.0 while it was 6.5 for Paenibacillus sp., B. bataviensis, and B. megaterium showed optimum pectinase activity at 60°C and Paenibacillus sp. at 40°C. Metal ions such as Na+ and K+ improved the activity of pectinase produced by the three isolates when compared to the effect of Zn2+ and Mn2+. The molecular weights of the enzymes were also estimated by gel filtration as 29,512 da, 32,359 da, and 25,119 da for Paenibacillus sp., B. megaterium and B. bataviensis respectively. The study has provided a platform for further investigation into the biochemical characterization of the enzyme, and optimization of culture conditions to scale up pectinase production for commercial exploitation.

  20. The role of the arbuscular mycorrhiza-associated rhizobacteria in the biocontrol of soilborne phyto pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Lioussanne, L.

    2010-07-01

    The mutualistic symbiosis of most land plants with arbuscular mycorrhizal (AM) fungi has been shown to favor mineral and water nutrition and to increase resistance to abiotic and biotic stresses. This review reports the main mechanisms involved in the control of the disease symptoms and of the intraradical proliferation of soilborne phytopathogens by root colonization with AM fungi, with a special emphasis on the role of the rhizobacteria shown to be specifically associated with the AM extraradical network and the mycorrhizosphere (the soil zone with particular characteristics under the influence of the root/AM association). The mycorrhizosphere would constitute an environment conducive to microorganisms antagonistic to pathogen proliferation. Moreover, attempts to identify rhizobacteria from AM structures and/or the mycorrhizosphere often lead to the isolation of organisms showing strong properties of antagonism on various soilborne pathogens. The ability of AM fungi to control soilborne diseases would be strongly related to their capacity to specifically stimulate the establishment of rhizobacteria unfavorable to pathogen development within the mycorrhizosphere before root infection. Current knowledge concerning the mechanisms involved in AM/rhizobacteria interactions are also described in this review. (Author) 101 refs.

  1. Effect of four growth-promoting rhizobacteria on crown blight caused by Phytophthora capsici in sweet pepper (Capsicum annuum

    Directory of Open Access Journals (Sweden)

    Carlos Ramírez

    2015-11-01

    Full Text Available Crown blight, caused by Phytophthora capsici, is the most important disease of pepper (Capsicum annuum in the world and causes great economic losses in Costa Rica. Alternatives to chemical control against this disease are crucial to prevent damage to human health and the environment. The antagonism of Plant-Growth-Promoting Rhizobacteria (PGPR on P. capsici, and its ability to reduce wilt in pepper plants were evaluated. PGPR strains previously isolated from sugarcane and rice were identified, using 16S RNA gene sequence, as Pseudomonas fluorescens PC4, Stenotrophomonas rhizophila PC9, Pseudomonas fragi PC11 and Azospirillum lipoferum PCJ2. The inhibition of P. capcisi growth was evaluated in vitro, in the presence of the PGPR. The effect of the four bacterial strains on pepper plants inoculated with P. capsici (100 zoospores.plant-1 was evaluated in the greenhouse. P. fluorescens PC4, S. rhizophila PC9 and A. lipoferum PCJ2, inhibited in vitro growth of the oomycete by 54%, 30% and 50 % respectively, while S. rhizophila PC9 increased by 14% shoot fresh weight of pepper plants at the greenhouse. Furthermore, PCJ2 and PC9 strains reduced the shoot and root severity of the disease, and PCJ2-inoculated plants showed no symptoms at all, indicating that PC9 and PCJ2 are promising rizobacteria for the control of crown blight in pepper.

  2. Synergistic use of biochar, compost and plant growth-promoting rhizobacteria for enhancing cucumber growth under water deficit conditions.

    Science.gov (United States)

    Nadeem, Sajid M; Imran, Muhammad; Naveed, Muhammad; Khan, Muhammad Y; Ahmad, Maqshoof; Zahir, Zahir A; Crowley, David E

    2017-12-01

    Limited information is available about the effectiveness of biochar with plant growth-promoting rhizobacteria (PGPR) and compost. A greenhouse study was conducted to evaluate the effect of biochar in combination with compost and PGPR (Pseudomonas fluorescens) for alleviating water deficit stress. Both inoculated and un-inoculated cucumber seeds were sown in soil treated with biochar, compost and biochar + compost. Three water levels - field capacity (D0), 75% field capacity (D1) and 50% field capacity (D2) - were maintained. The results showed that water deficit stress significantly suppressed the growth of cucumber; however, synergistic use of biochar, compost and PGPR mitigated the negative impact of stress. At D2, the synergistic use of biochar, compost and PGPR caused significant increases in shoot length, shoot biomass, root length and root biomass, which were respectively 88, 77, 89 and 74% more than in the un-inoculated control. Significant improvements in chlorophyll and relative water contents as well as reduction in leaf electrolyte leakage demonstrated the effectiveness of this approach. Moreover, the highest population of P. fluorescens was observed where biochar and compost were applied together. These results suggest that application of biochar with PGPR and/or compost could be an effective strategy for enhancing plant growth under stress. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Effect of salt-tolerant plant growth-promoting rhizobacteria on wheat plants and soil health in a saline environment.

    Science.gov (United States)

    Upadhyay, S K; Singh, D P

    2015-01-01

    Salt-tolerant plant growth-promoting rhizobacteria (ST-PGPR) significantly influence the growth and yield of wheat crops in saline soil. Wheat growth improved in pots with inoculation of all nine ST-PGPR (ECe = 4.3 dS·m(-1) ; greenhouse experiment), while maximum growth and dry biomass was observed in isolate SU18 Arthrobacter sp.; simultaneously, all ST-PGPR improved soil health in treated pot soil over controls. In the field experiment, maximum wheat root dry weight and shoot biomass was observed after inoculation with SU44 B. aquimaris, and SU8 B. aquimaris, respectively, after 60 and 90 days. Isolate SU8 B. aquimaris, induced significantly higher proline and total soluble sugar accumulation in wheat, while isolate SU44 B. aquimaris, resulted in higher accumulation of reducing sugars after 60 days. Percentage nitrogen (N), potassium (K) and phosphorus (P) in leaves of wheat increased significantly after inoculation with ST-PGPR, as compared to un-inoculated plants. Isolate SU47 B. subtilis showed maximum reduction of sodium (Na) content in wheat leaves of about 23% at both 60 and 90 days after sowing, and produced the best yield of around 17.8% more than the control. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Members of the genera Paenibacillus and Rhodococcus harbor genes homologous to enterococcal glycopeptide resistance genes vanA and vanB

    DEFF Research Database (Denmark)

    Guardabassi, L.; Christensen, H.; Hasman, Henrik

    2004-01-01

    Genes homologous to enterococcal glycopeptide resistance genes vanA and vanB were found in glycopeptide-resistant Paenibacillus and Rhodococcus strains from soil. The putative D-Ala:D-Lac ligase genes in Paenibacillus thiaminolyticus PT-2B1 and Paenibacillus apiarius PA-B2B were closely related...

  5. Purification and Partial characterization of manganese peroxidase from Bacillus pumilus AND Paenibacillus sp.

    Directory of Open Access Journals (Sweden)

    Patrícia Lopes de Oliveira

    2009-12-01

    Full Text Available The production of manganese peroxidase (MnP from Bacillus pumilus and Paenibacillus sp. was studied under absence and presence of the inducers indulin AT, guayacol, veratryl alcohol, lignosulfonic acid and lignosulfonic acid desulfonated. Indulin AT increased the activity of B. pumilus MnP up to 31.66 U/L after 8 h, but no improve was observed for Paenibacillus sp., which reached maximum activity (12.22 U/L after 20 h. Both MnPs produced by these microorganisms were purified in phenyl sepharose resin and the proteins from crude extracts were eluted in two fractions. However, only the first fraction of each extract exhibited MnP activities. Tests in different pH and temperature values, from pH 5.0 to pH 10.0 and 30 ºC to 60 ºC, respectively, were carried out with the purified MnP. The maximum activity reached for B. pumilus and Paenibacillus sp. MnPs were 4.3 U/L at pH 8.0 and 25 ºC and 11.74 U/L at pH 9.0 and 35 ºC, respectively. The molar masses determined by SDS-PAGE gel eletrophoresis were 25 kDa and 40 kDa, respectively, for the purified enzyme from B. pumilus and Paenibacillus sp.

  6. Conversion of Squid Pens to Chitosanases and Proteases via Paenibacillus sp. TKU042

    Directory of Open Access Journals (Sweden)

    Chien Thang Doan

    2018-03-01

    Full Text Available Chitosanases and proteases have received much attention due to their wide range of applications. Four kinds of chitinous materials, squid pens, shrimp heads, demineralized shrimp shells and demineralized crab shells, were used as the sole carbon and nitrogen (C/N source to produce chitosanases, proteases and α-glucosidase inhibitors (αGI by four different strains of Paenibacillus. Chitosanase productivity was highest in the culture supernatants using squid pens as the sole C/N source. The maximum chitosanase activity of fermented squid pens (0.759 U/mL was compared to that of fermented shrimp heads (0.397 U/mL, demineralized shrimp shells (0.201 U/mL and demineralized crab shells (0.216 U/mL. A squid pen concentration of 0.5% was suitable for chitosanase, protease and αGI production via Paenibacillus sp. TKU042. Multi-purification, including ethanol precipitation and column chromatography of Macro-Prep High S as well as Macro-Prep DEAE (diethylaminoethyl, led to the isolation of Paenibacillus sp. TKU042 chitosanase and protease with molecular weights of 70 and 35 kDa, respectively. For comparison, 16 chitinolytic bacteria, including strains of Paenibacillus, were investigated for the production of chitinase, exochitinase, chitosanase, protease and αGI using two kinds of chitinous sources.

  7. Plant responses to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Loon, L.C. van

    2007-01-01

    Non-pathogenic soilborne microorganisms can promote plant growth, as well as suppress diseases. Plant growth promotion is taken to result from improved nutrient acquisition or hormonal stimulation. Disease suppression can occur through microbial antagonism or induction of resistance in the plant.

  8. Characterization of four Paenibacillus species isolated from pasteurized, chilled ready-to-eat meals.

    Science.gov (United States)

    Helmond, Mariette; Nierop Groot, Masja N; van Bokhorst-van de Veen, Hermien

    2017-07-03

    Food spoilage is often caused by microorganisms. The predominant spoilage microorganisms of pasteurized, chilled ready-to-eat (RTE) mixed rice-vegetable meals stored at 7°C were isolated and determined as Paenibacillus species. These sporeforming psychrotrophic bacteria are well adapted to grow in the starch-rich environment of pasteurized and chilled meals. Growth of the Paenibacillus isolates appeared to be delayed by decreased (5.5%, corresponding with an a w meal on spore inactivation, heat-inactivation kinetics were determined and D-values were calculated. According to these kinetics, pasteurization up to 90°C, necessary for inactivation of vegetative spoilage microorganisms and pathogens, does not significantly contribute to the inactivation of Paenibacillus spores in the meals. Furthermore, outgrowth of pasteurized spores was determined in the mixed rice-vegetable meal at several temperatures; P. terrae FBR-61 and P. pabuli FBR-75 isolates did not substantially increase in numbers during storage at 2°C, but had a significant increase within a month of storage at 4°C or within several days at 22°C. Overall, this work shows the importance of Paenibacillus species as spoilage microorganisms of pasteurized, chilled RTE meals and that the meals' matrix, processing conditions, and storage temperature are important hurdles to control microbial meal spoilage. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Nematicidal effect of rhizobacteria on plant-parasitic nematodes associated with vineyards.

    Science.gov (United States)

    Aballay, E; Prodan, S; Zamorano, A; Castaneda-Alvarez, C

    2017-07-01

    The action of metabolites and exoenzymes from rhizobacteria on different plant-parasitic nematodes has an influence on the nematicidal efficacy of the microbe. Seven rhizobacteria, divided into two bacterial groups, were evaluated in vitro for nematicidal activity on Meloidogyne ethiopica and Xiphinema index. The direct effect of their filtrates on egg hatching and juveniles of M. ethiopica as well as mobile stages of X. index was evaluated during a 72-h period. The production of four exoenzymes and two metabolites associated with nematode mortality was investigated. Molecular characterization of three isolates was performed, and the physiological profiles and lipase activity of all isolates were obtained using the BIOLOG EcoPlate system. While chitinase and collagenase were measured using the BIOLOG MT2 plate system, protease, hydrogen cyanide and hydrogen sulphide were directly determined in Petri dishes. Nematode mobile stages exposure to the bacterial filtrate revealed a nematicidal effect up to 93.7% on X. Index and up to 83.3% on M. ethiopica. The control of egg hatching varied between 35 and 85%. A positive correlation was found between the mortality of both nematode mobile stages and the concerted activities of the bacterial enzymes as well as the level of the volatile metabolites. The nematicidal effect of rhizobacteria strains varies by nematode genera and among the developmental stages evaluated.

  10. Rhizobacteria in mycorrhizosphere improved plant health and yield of banana by offering proper nourishment and protection against diseases.

    Science.gov (United States)

    Phirke, Niteen V; Kothari, Raman M; Chincholkar, Sudhir B

    2008-12-01

    The corporate R&D banana orchards of Musa paradisiaca (dwarf Cavendish AAA, var. shrimanti) on a medium black alluvial soil with low nutrients harboured diversified species of vesicular-arbuscular mycorrhizal (VAM) fungi. These fungi infected the roots severely (69.2%), showed elevated (69.8 g(-1) soil) spore density, increased soil bacterial density (245 x 10(8) cfu g(-1)), produced siderophores (58.2%) and reduced nematode population (2.3 g(-1)) in the mycorrhizosphere of plants for integrated plant nutrition management (IPNM) system as compared to traditional treatment of applying chemical fertilisers alone and other test treatments. The interactions of plant roots with native VAM and local and applied rhizobacteria in the matrix of soil conditioner enabled proper nourishment and protection of crop in IPNM treatment as compared to traditional way. Hence, exploitation of plant growth promoting rhizobacteria through judiciously designed IPNM system revealed the (a) relatively increased banana productivity (21.6%, 76 MT ha(-1)), (b) least occurrence of fusarial wilt and negligible evidence of Sigatoka, (c) saving of 50% chemical fertilisers and (d) permitted control over soil fertility in producer's favour over traditional cultivation practices. These findings are discussed in detail.

  11. Paenibacillus sonchi sp. nov., a nitrogen-fixing species isolated from the rhizosphere of Sonchus oleraceus.

    Science.gov (United States)

    Hong, Yuan-Yuan; Ma, Yu-Chao; Zhou, Yu-Guang; Gao, Fei; Liu, Hong-Can; Chen, San-Feng

    2009-11-01

    A nitrogen-fixing bacterium, designated strain X19-5(T), was isolated from rhizosphere soil of Sonchus oleraceus. Phylogenetic analysis based on a fragment of the nifH gene and the full-length 16S rRNA gene sequence revealed that strain X19-5(T) was a member of the genus Paenibacillus. Strain X19-5(T) showed the highest 16S rRNA gene sequence similarity (98.8 %) with Paenibacillus graminis RSA19(T) and below 97 % similarity with other recognized members of the genus. The level of DNA-DNA relatedness between strain X19-5(T) and P. graminis RSA19(T) was 45.7 %. The DNA G+C content of strain X19-5(T) was 46.8 mol%. The major fatty acids were anteiso-C(15 : 0), C(16 : 0) and iso-C(16 : 0). On the basis of its phenotypic characteristics and the level of DNA-DNA hybridization, strain X19-5(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus sonchi sp. nov. is proposed. The type strain is X19-5(T) (=CCBAU 83901(T)=LMG 24727(T)).

  12. Drought-Tolerant Plant Growth-Promoting Rhizobacteria Associated with Foxtail Millet in a Semi-arid Agroecosystem and Their Potential in Alleviating Drought Stress

    Directory of Open Access Journals (Sweden)

    Xuguang Niu

    2018-01-01

    Full Text Available The application of plant growth promoting rhizobacteria (PGPR to agro-ecosystems is considered to have the potential for improving plant growth in extreme environments featured by water shortage. Herein, we isolated bacterial strains from foxtail millet (Setaria italica L., a drought-tolerant crop cultivated in semiarid regions in the northeast of China. Four isolates were initially selected for their ability to produce ACC deaminase as well as drought tolerance. The isolates were identified as Pseudomonas fluorescens, Enterobacter hormaechei, and Pseudomonas migulae on the basis of 16S rRNA sequence analysis. All of these drought-tolerant isolates were able to produce EPS (exopolysaccharide. Inoculation with these strains stimulated seed germination and seedling growth under drought stress. Pseudomonas fluorescens DR7 showed the highest level of ACC deaminase and EPS-producing activity. DR7 could efficiently colonize the root adhering soil, increased soil moisture, and enhance the root adhering soil/root tissue ratio. These results suggest drought tolerant PGPR from foxtail millet could enhance plant growth under drought stress conditions and serve as effective bioinoculants to sustain agricultural production in arid regions.

  13. Short Communication Synergistic effect of rhizobia and plant growth promoting rhizobacteria on the growth and nodulation of lentil seedlings under axenic conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Zafar-ul-Hye

    2013-05-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR containing ACC-deaminase in combination with rhizobia can improve the growth and nodulation in plants by suppressing the endogenous level of ethylene. In the present study, ten strains, each of PGPR and rhizobia from the previously screened cultures were tested for their effect as co-inoculants on growth and nodulation of lentil in growth pouches under axenic conditions. Results showed that most of the combinations improved the lentil growth as compared to the un-inoculated control. Maximum increase in shoot length (1.87 fold, root length (1.97 fold and total biomass (1.98 fold over the un-inoculated control was observed in the treatment where the lentil seedlings were inoculated with the combination Z24P10. Co-inoculation also improved the nodulation in lentil and the maximum number of nodules plant-1 (24 nodules were observed in the combination Z22P10. However, there was no nodulation in few combinations. It is concluded that the co-inoculation with rhizobia and PGPR containing ACC-deaminase has improved the growth and nodulation in lentil under axenic conditions and the selected combinations may be evaluated in pot and field trials

  14. Greenhouse and field assessment of rhizobacteria to control guava decline

    Directory of Open Access Journals (Sweden)

    Alexandre Macedo Almeida

    2011-01-01

    Full Text Available In an effort to devise a biological strategy to control guava decline, 120 rhizobacteria isolates were obtained from symptomless guava trees located in Meloidogyne enterolobii-infested orchards. Of those isolates, 44 were assessed for their potential to reduce nematode's reproduction: for each isolate, six guava stem cuttings were embedded for eight hours with bacterial suspension and transplanted. Upon development of the roots, the plants were inoculated with 2000 nematode eggs and allowed to grow for four months under greenhouse. Seedlings embedded with water, inoculated or not with the nematode, served as controls. All treatments were equivalent in the five variables that assessed plant development. Several rhizobacteria reduced (p<0.05 the final nematode population (Fp, Fp/gram of root and reproduction factor, although not to satisfactory levels. Subsequently, a two-year experiment was set up in a guava orchard affected by guava decline, in which three of the most effective rhizobacterial isolates were compared with the biological products Nemat® and Nemaplus® for their ability to reduce variables related to nematode parasitism and increase guava productivity. Seven bimonthly applications of these treatments under the tree canopy were unable to reduce nematode parasitism and increase productivity. The decline and death of some plants forced the experiment to be stopped after the first harvest. In conclusion, rhizobacteria applications seem unable to reduce the parasitism of M. enterolobii on guava plants, and even less to reduce the extensive root decay or alleviate the physiological stress suffered by trees affected by guava decline.

  15. Complete genome sequence of Paenibacillus sp. strain JDR-2

    Science.gov (United States)

    Virginia Chow; Guang Nong; Franz J. St. John; John D. Rice; Ellen Dickstein; Olga Chertkov; David Bruce; Chris Detter; Thomas Brettin; James Han; Tanja Woyke; Sam Pitluck; Matt Nolan; Amrita Pati; Joel Martin; Alex Copeland; Miriam L. Land; Lynne Goodwin; Jeffrey B. Jones; Lonnie O. Ingram; Keelnathan T. Shanmugam; James F. Preston

    2012-01-01

    Paenibacillus sp. strain JDR-2, an aggressively xylanolytic bacterium isolated from sweetgum (Liquidambar styraciflua) wood, is able to efficiently depolymerize, assimilate and metabolize 4-O-methylglucuronoxylan, the predominant structural component of hardwood hemicelluloses. A basis for this capability was first supported by...

  16. Real-Time PCR Detection of Paenibacillus spp. in Raw Milk To Predict Shelf Life Performance of Pasteurized Fluid Milk Products

    OpenAIRE

    Ranieri, Matthew L.; Ivy, Reid A.; Mitchell, W. Robert; Call, Emma; Masiello, Stephanie N.; Wiedmann, Martin; Boor, Kathryn J.

    2012-01-01

    Psychrotolerant sporeformers, specifically Paenibacillus spp., are important spoilage bacteria for pasteurized, refrigerated foods such as fluid milk. While Paenibacillus spp. have been isolated from farm environments, raw milk, processing plant environments, and pasteurized fluid milk, no information on the number of Paenibacillus spp. that need to be present in raw milk to cause pasteurized milk spoilage was available. A real-time PCR assay targeting the 16S rRNA gene was designed to detect...

  17. Salinity tolerance of Dodonaea viscosa L. inoculated with plant growth-promoting rhizobacteria: assessed based on seed germination and seedling growth characteristics

    Directory of Open Access Journals (Sweden)

    Yousefi Sonia

    2017-06-01

    Full Text Available The study was conducted to evaluate the potential of different strains of plant growth-promoting rhizobacteria (PGPR to reduce the effects of salinity stress on the medicinal hopbush plant. The bacterium factor was applied at five levels (non-inoculated, inoculated by Pseudomonas putida, Azospirillum lipoferum + Pseudomonas putida, Azotobacter chroococcum + Pseudomonas putida, and Azospirillum lipoferum + Azotobacter chroococcum + Pseudomonas putida, and the salinity stress at six levels: 0, 5, 10, 15, 20, and 50 dS m-1. The results revealed that Pseudomonas putida showed maximal germination percentage and rate at 20 dS m-1 (18.33% and 0.35 seed per day, respectively. The strongest effect among the treatments was obtained with the treatment combining the given 3 bacteria at 15 dS m-1 salinity stress. This treatment increased the root fresh and dry weights by 31% and 87.5%, respectively (compared to the control. Our results indicate that these bacteria applied on hopbush affected positively both its germination and root growth. The plant compatibility with the three bacteria was found good, and the treatments combining Pseudomonas putida with the other one or two bacteria discussed in this study can be applied in nurseries in order to restore and extend the area of hopbush forests and akin dry stands.

  18. Lettuce and rhizosphere microbiome responses to growth promoting Pseudomonas species under field conditions

    NARCIS (Netherlands)

    Cipriano, M.A.P.; Lupatini, M.; Santos, L.; Silva, M. da; Roesch, L.F.W.; Destefano, S.; Freitas, S.; Kuramae, E.E.

    2016-01-01

    Plant growth promoting rhizobacteria (PGPR) are well described and recommended for several crops worldwide. However, one of the most common problems in PGPR research is the difficulty in obtaining reproducible results. Furthermore, few studies have evaluated plant growth promotion and soil microbial

  19. Isolation and characterization of a novel polychlorinated biphenyl-degrading bacterium, Paenibacillus sp. KBC101

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, M.; Ezaki, S.; Suzuki, N.; Kurane, R. [Kubota Corporation, Ryuugasaki City (Japan). Biotechnology Research Centre

    2005-07-01

    The biphenyl-utilizing bacterial strain KBC101 has been newly isolated from soil. Biphenyl-grown cells of KBC101 efficiently degraded di- to nonachlorobiphenyls. The isolate was identified as Paenibacillus sp. with respect to its 16S rDNA sequence and fatty acid profiles, as well as various biological and physiological characteristics. In the case of highly chlorinated biphenyl (polychlorinated biphenyl; PCB) congeners, the degradation activities of this strain were superior to those of the previously reported strong PCB degrader, Rhodococcus sp. RHA1. Recalcitrant coplanar PCBs, such as 3,4,3',4'-CB, were also efficiently degraded by strain KBC101 cells. This is the first report of a representative of the genus Paenibacillus capable of degrading PCBs. In addition to growth of biphenyl, strain KBC101 could grow on dibenzofuran, xanthene, benzophenone, anthrone, phenanthrene, napthalene, fluorene, fluoranthene, and chrysene as sole sources of carbon and energy. Paenibacillus sp. strain KBC101 presented heterogeneous degradation profiles toward various aromatic compounds. (orig.)

  20. The interactive effects of chelator, fertilizer, and rhizobacteria for enhancing phytoremediation of heavy metal contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Cutright, T.J. [Dept. of Civil Engineering, Univ. of Akron, Akron, OH (United States)

    2002-07-01

    The role of chelator, fertilizer, and enriched rhizobacteria in facilitating Cd, Cr, and Ni accumulation by Helianthus annuus was studied. It was found that by adding a synthetic chelator, EDTA, the shoot concentrations of Cd and Ni were significantly increased from 34.2 mg kg{sup -1} and 14.5 mg kg{sup -1} to 115 mg kg{sup -1} and 117 mg kg{sup -1}, respectively. However, the total biomass of plants was drastically decreased by 50 to 60%. Compared with this treatment, inoculating enriched rhizobacteria to plants grown under similar conditions maintained the surged shoot concentrations of Cd and Ni while increasing the plants biomass by more than 1.6-fold. It was also found that introducing a commercial fertilizer, Hydro-Gro trademark, to plants significantly increased the Ni accumulation by 3-fold and the plant biomass by 1.43-fold. These results suggest that combing fertilizers, chelators and/or rhizobacteria might provide a more effective approach for enhancing phytoremediation. (orig.)

  1. Effect of specific plant-growth-promoting rhizobacteria (PGPR) on growth and uptake of neonicotinoid insecticide thiamethoxam in corn (Zea mays L.) seedlings.

    Science.gov (United States)

    Myresiotis, Charalampos K; Vryzas, Zisis; Papadopoulou-Mourkidou, Euphemia

    2015-09-01

    Corn (Zea mays L.) is one of the most important cereal crops in the world and is used for food, feed and energy. Inoculation with plant-growth-promoting rhizobacteria (PGPR) would reduce the use of chemical fertilisers and pesticides and could be suggested as an alternative practice for sustainable production of corn in modern agricultural systems. In this study, the effect of two Bacillus PGPR formulated products, Companion (B. subtilis GB03) and FZB24 (B. subtilis FZB24), on corn growth and root uptake of insecticide thiamethoxam was investigated. All bacterial treatments enhanced root biomass production by 38-65% compared with the uninoculated control, with no stimulatory effect of PGPR on above-ground biomass of corn. The uptake results revealed that, in plants inoculated with the PGPR B. subtilis FZB24 and B. subtilis GB03, singly or in combination, the uptake and/or systemic translocation of thiamethoxam in the above-ground corn parts was significantly higher at the different growth ages compared with the control receiving no bacterial treatment. The findings suggest that the PGPR-elicited enhanced uptake of thiamethoxam could lead to improved efficiency of thiamethoxam using reduced rates of pesticides in combination with PGPR as an alternative crop protection technique. © 2014 Society of Chemical Industry.

  2. Effects of plant growth promoting rhizobacteria (PGPR and cover crops on seed germination and early establishment of field dodder (Cuscuta campestris Yunk.

    Directory of Open Access Journals (Sweden)

    Sarić-Krsmanović Marija

    2017-01-01

    Full Text Available Several bacterial cultures: Bacillus licheniformis (MO1, B. pumilus (MO2, and B. amyloliquefaciens (MO3, isolated from manure; B. megatherium ZP6 (MO4 isolated from maize rhizosphere; Azotobacter chroococcum Ps1 (MO5 and Pseudomonas fluorescens (MO6, were used to test the influence of plant growth promoting rhizobacteria (PGPR on seed germination and germination rate of field dodder (Cuscuta campestris Yunk.. Also, to examine the effect of host seeds on germination and initial growth of seedlings of field dodder plants in the dark and under white light, the seeds of four host plants were used (watermelon, red clover, alfalfa and sugar beet. Germinated seeds were counted daily over a ten-day period and the length of seedlings was measured on the final day. The results show that treatments MO3, MO4 and MO6 had inhibitory effects (15%, 65% and 52%, respectively, while treatments MO1, MO2 and MO5 had stimulating effects (3%, 3% and 19%, respectively on seed germination of field dodder. The data for host seeds show that light was a significant initial factor (83-95%, control 95% for stimulating seed germination of field dodder plants, apart from host presence (73-79%, control 80%.

  3. Complete genome sequence of Paenibacillus riograndensis SBR5(T), a Gram-positive diazotrophic rhizobacterium.

    Science.gov (United States)

    Brito, Luciana Fernandes; Bach, Evelise; Kalinowski, Jörn; Rückert, Christian; Wibberg, Daniel; Passaglia, Luciane M; Wendisch, Volker F

    2015-08-10

    Paenibacillus riograndensis is a Gram-positive rhizobacterium which exhibits plant growth promoting activities. It was isolated from the rhizosphere of wheat grown in the state of Rio Grande do Sul, Brazil. Here we announce the complete genome sequence of P. riograndensis strain SBR5(T). The genome of P. riograndensis SBR5(T) consists of a circular chromosome of 7,893,056bps. The genome was finished and fully annotated, containing 6705 protein coding genes, 87 tRNAs and 27 rRNAs. The knowledge of the complete genome helped to explain why P. riograndensis SBR5(T) can grow with the carbon sources arabinose and mannitol, but not myo-inositol, and to explain physiological features such as biotin auxotrophy and antibiotic resistances. The genome sequence will be valuable for functional genomics and ecological studies as well as for application of P. riograndensis SBR5(T) as plant growth-promoting rhizobacterium. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Rizobactérias formadoras de endósporos associadas a Tibouchina urvilleana de áreas impactadas por rejeitos da mineração do carvão Endospore-forming rhizobacteria associated with Tibouchina urvilleana in areas affected by coal-mining waste

    Directory of Open Access Journals (Sweden)

    Bianca de Aguiar Pereira

    2010-04-01

    Full Text Available Os rejeitos da mineração do carvão podem elevar a concentração de metais pesados e dificultar o crescimento de plantas nessas áreas. Uma estratégia para recuperação desses ambientes é por meio da associação de microrganismos à rizosfera que podem auxiliar na promoção de crescimento de plantas, bem como na diminuição da toxicidade por metais pesados. O presente trabalho teve como objetivos o isolamento e a identificação de rizobactérias formadoras de endósporos (RFE de áreas impactadas por rejeitos da mineração de carvão, num depósito no município de Capivari de Baixo, Santa Catarina (Brasil, bem como a avaliação de seus potenciais para auxiliar plantas na revegetação de ecossistemas degradados por essa atividade, por meio de testes de resistência a elementos metálicos e produção de sideróforos. Das RFE identificadas, as do gênero Bacillus foram mais frequentes, e entre as duas áreas de estudo observaram-se grupos bacterianos distintos. As linhagens provenientes da área dos rejeitos piritosos foram mais resistentes a Ni e Cu. Dez linhagens pertencentes aos gêneros Bacillus, Paenibacillus e Aneurinibacillus, além de resistirem a um maior número dos metais pesados testados, produziram sideróforos e, portanto, foram consideradas com maior potencial para auxiliar o crescimento de plantas em áreas contaminadas com metais pesados.Coal mining rejects can raise the concentration of heavy metals and impede the growth of plants in these areas. One strategy for restoring these environments is the association of microorganisms with the rhizosphere, which can help promote plant growth, as well as decreasing the toxicity of heavy metals. The objective of this study was to isolate and identify endospore-forming rhizobacteria (EFR in areas affected by coal-mining waste, in a deposit in the municipal district of Capivari de Baixo, Santa Catarina (Brazil and to evaluate the plant growth-promoting potential of bacteria in

  5. Plant-fed versus chemicals-fed rhizobacteria of Lucerne: Plant-only teabags culture media not only increase culturability of rhizobacteria but also recover a previously uncultured Lysobacter sp., Novosphingobium sp. and Pedobacter sp.

    Science.gov (United States)

    Hegazi, Nabil A; Sarhan, Mohamed S; Fayez, Mohamed; Patz, Sascha; Murphy, Brian R; Ruppel, Silke

    2017-01-01

    In an effort to axenically culture the previously uncultivable populations of the rhizobacteria of Lucerne (Medicago sativa L.), we propose plant-only teabags culture media to mimic the nutritional matrix available in the rhizosphere. Here, we show that culture media prepared from Lucerne powder teabags substantially increased the cultivability of Lucerne rhizobacteria compared with a standard nutrient agar, where we found that the cultivable populations significantly increased by up to 60% of the total bacterial numbers as estimated by Quantitative Real-time Polymerase Chain Reaction (qRT-PCR). Cluster analysis of 16S rDNA Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) of cultivable Colony-Forming Units (CFUs) revealed a more distinct composition and separation of bacterial populations recovered on the plant-only teabags culture media than those developed on a standard nutrient agar. Further, the new plant medium gave preference to the micro-symbiont Sinorhizobium meliloti, and succeeded in isolating a number of not-yet-cultured bacteria, most closely matched to Novosphingobium sp., Lysobacter sp. and Pedobacter sp. The present study may encourage other researchers to consider moving from the well-established standard culture media to the challenging new plant-only culture media. Such a move may reveal previously hidden members of rhizobacteria, and help to further explore their potential environmental impacts.

  6. Getting the ecology into the interactions between plants and the plant-growth promoting bacterium Pseudomonas fluorescens

    NARCIS (Netherlands)

    Hol, W.H.G.; Bezemer, T.M.; Biere, A.

    2013-01-01

    Plant growth-promoting rhizobacteria (PGPR) are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas

  7. Impact of lead tolerant plant growth promoting rhizobacteria on growth, physiology, antioxidant activities, yield and lead content in sunflower in lead contaminated soil.

    Science.gov (United States)

    Saleem, Muhammad; Asghar, Hafiz Naeem; Zahir, Zahir Ahmad; Shahid, Muhammad

    2018-03-01

    Present study was conducted to evaluate the effect of lead tolerant plant growth promoting rhizobacteria (LTPGPR) on growth, physiology, yield, antioxidant activities and lead uptake in sunflower in soil contaminated with lead under pot conditions. Three pre-characterized LTPGP strains (S2 (Pseudomonas gessardii strain BLP141), S5 (Pseudomonas fluorescens A506) and S10 (Pseudomonas fluorescens strain LMG 2189)) were used to inoculate sunflower growing in soil contaminated with different levels (300, 600 and 900 mg kg -1 ) of lead by using lead nitrate salt as source of lead. Treatments were arranged according to completely randomized design with factorial arrangements. At harvesting, data regarding growth attributes (root shoot length, root shoot fresh and dry weights), yield per plant, physiological attributes (Chlorophyll 'a', 'b' and carotenoids content), antioxidant activities (Ascorbate peroxidase, catalase, superoxide dismutase and glutathione reductase), proline and malanodialdehyde content, and lead content in root, shoot and achenes of sunflower were recorded. Data were analysed by standard statistical procedures. Results showed that lead contamination reduced the plants growth, physiology and yield at all levels of lead stress. But application of LTPGPR in soil contaminated with lead improved plant growth, physiology, yield, and antioxidant activities, proline, and reduced the malanodialdehyde content (that is reduced by the application of different strains in lead contamination) of sunflower as compared to plants grown in soil without inoculation. Inoculation also promoted the uptake of lead in root, shoots and reduced the uptake of lead in achenes of plants as compared to plants in lead contamination without inoculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Paenibacillus aceti sp. nov., isolated from the traditional solid-state acetic acid fermentation culture of Chinese cereal vinegar.

    Science.gov (United States)

    Li, Pan; Lin, Weifeng; Liu, Xiong; Li, Sha; Luo, Lixin; Lin, Wei-Tie

    2016-09-01

    A Gram-stain-negative, rod-shaped, motile, endospore-forming, facultatively anaerobic bacterium, designated strain L14T, was isolated from the traditional acetic acid fermentation culture of Chinese cereal vinegars. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain L14T was affiliated to the genus Paenibacillus, most closely related to Paenibacillus motobuensis MC10T with 97.8 % similarity. Chemotaxonomic characterization supported the allocation of the strain to the genus Paenibacillus. The polar lipid profile of strain L14T contained the major compounds diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The predominant menaquinone was MK-7, and the major fatty acid components were anteiso-C15 : 0, iso-C15 : 0 and C16 : 0. The DNA G+C content of strain L14T was 49.9 mol%. The DNA-DNA relatedness value between strain L14T and P. motobuensis MC10T was 51.2 %. The results of physiological and biochemical tests allowed phenotypic differentiation of strain L14T from closely related species. On the basis of phenotypic and chemotaxonomic analyses, phylogenetic analysis and DNA-DNA relatedness values, strain L14T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus aceti sp. nov. is proposed. The type strain is L14T (=CGMCC 1.15420T=JCM 31170T).

  9. Laboratory study on influence of plant growth promoting ...

    African Journals Online (AJOL)

    The influence of rhizobacteria on the growth and tolerance of Zea mays (maize) in a petroleum hydrocarbon (crude oil) impacted medium was investigated. This study evaluated the effect of inoculating maize seeds with plant growth promoting rhizobacterial strains in a crude oil impacted medium. The rhizobacterial strains ...

  10. Suppression of crown and root rot of wheat by the rhizobacterium Paenibacillus polymyxa

    Directory of Open Access Journals (Sweden)

    Lamia LOUNACI

    2017-01-01

    Full Text Available A seedling bioassay was developed for screening a wheat root-associated rhizobacterial strain of Paenibacillus polymyxa for ability to suppress crown and root rot pathogens of wheat. The primary aim was to evaluate the ability of P. polymyxa to suppress Fusarium graminearum, F. culmorum, F. verticillioides and Microdochium nivale, the fungal pathogens responsible for Fusarium crown and root rot and head blight of wheat in Algeria. Bioassays conducted under controlled conditions indicated that seed treatments with P. polymyxa strain SGK2 significantly reduced disease symptoms caused by all four fungal pathogens. Plant growth promotion (increased shoot and root dry weights, however, depended on the pathogen tested. Our results indicate that seed treatments with a biocontrol agent could be an additional strategy for management of wheat crown and root rot pathogens.

  11. Genetic diversity of nifH gene sequences in Paenibacillus azotofixans strains and soil samples analyzed by denaturing gradiënt gel electrophoresis of PCR-amplified gene fragments

    NARCIS (Netherlands)

    Rosado, A.S.; Duarte, G.F.; Seldin, L.; Elsas, van J.D.

    1998-01-01

    The diversity of dinitrogenase reductase gene (nifH) fragments in Paenibacillus azotofixans strains was investigated by using molecular methods. The partial nifH gene sequences of eight P. azotofixans strains, as well as one strain each of the close relatives Paenibacillus durum, Paenibacillus

  12. Plant-based culture media: Efficiently support culturing rhizobacteria and correctly mirror their in-situ diversity.

    Science.gov (United States)

    Youssef, Hanan H; Hamza, Mervat A; Fayez, Mohamed; Mourad, Elhussein F; Saleh, Mohamed Y; Sarhan, Mohamed S; Suker, Ragab M; Eltahlawy, Asmaa A; Nemr, Rahma A; El-Tahan, Mahmod; Ruppel, Silke; Hegazi, Nabil A

    2016-03-01

    Our previous publications and the data presented here provide evidences on the ability of plant-based culture media to optimize the cultivability of rhizobacteria and to support their recovery from plant-soil environments. Compared to the tested chemically-synthetic culture media (e.g. nutrient agar and N-deficient combined-carbon sources media), slurry homogenates, crude saps, juices and powders of cactus (Opuntia ficus-indica) and succulent plants (Aloe vera and Aloe arborescens) were rich enough to support growth of rhizobacteria. Representative isolates of Enterobacter spp., Klebsiella spp., Bacillus spp. and Azospirillum spp. exhibited good growth on agar plates of such plant-based culture media. Cell growth and biomass production in liquid batch cultures were comparable to those reported with the synthetic culture media. In addition, the tested plant-based culture media efficiently recovered populations of rhizobacteria associated to plant roots. Culturable populations of >10(6)-10(8) cfu g(-1) were recovered from the ecto- and endo-rhizospheres of tested host plants. More than 100 endophytic culture-dependent isolates were secured and subjected to morphophysiological identification. Factor and cluster analyses indicated the unique community structure, on species, genera, class and phyla levels, of the culturable population recovered with plant-based culture media, being distinct from that obtained with the chemically-synthetic culture media. Proteobacteria were the dominant (78.8%) on plant-based agar culture medium compared to only 31% on nutrient agar, while Firmicutes prevailed on nutrient agar (69%) compared to the plant-based agar culture media (18.2%). Bacteroidetes, represented by Chryseobacterium indologenes, was only reported (3%) among the culturable rhizobacteria community of the plant-based agar culture medium.

  13. Application of a novel Paenibacillus-specific PCR-DGGE method and sequence analysis to assess the diversity of Paenibacillus spp. in the maize rhizosphere

    NARCIS (Netherlands)

    Silva, da K.R.A.; Salles, J.F.; Seldin, L.; Elsas, van J.D.

    2003-01-01

    In this study, a Paenibacillus-specific PCR system, based on the specific primer PAEN515F in combination with bacterial primer R1401, was tested and used to amplify specific fragments of the 16S rRNA gene from rhizosphere DNA. The amplicons were used in a second (semi-nested) PCR for DGGE, in which

  14. Application of a novel Paenibacillus-specific PCR-DGGE method and sequence analysis to assess the diversity of Paenibacillus spp. in the maize rhizosphere.

    NARCIS (Netherlands)

    da Silva, Katia Regina Araujo; Falcao Salles, Joana; Seldin, Lucy; van Elsas, Jan

    In this study, a Paenibacillus-specific PCR system, based on the specific primer PAEN515F in combination with bacterial primer R1401, was tested and used to amplify specific fragments of the 16S rRNA gene from rhizosphere DNA. The amplicons were used in a second (semi-nested) PCR for DGGE, in which

  15. Effects of rhizobia and plant growth promoting bacteria inoculation ...

    African Journals Online (AJOL)

    Plant growth promoting rhizobacteria (PGPR) stimulate plant growth by producing phytohormone which enhances the growth and physiological activities of the host plant. Recently, legume bacteria (Rhizobium spp.) have been considered as a PGPR for legume as well as non-legumes and have the potential for growth ...

  16. Degradation of phytosterols in tobacco waste extract by a novel Paenibacillus sp.

    Science.gov (United States)

    Ye, Jianbin; Zhang, Zhan; Yan, Ji; Hao, Hui; Liu, Xiangzhen; Yang, Zongcan; Ma, Ke; Yang, Xuepeng; Mao, Duobin; Zhou, Hao

    2017-11-01

    Phytosterols have been demonstrated to be precursors of polycyclic aromatic hydrocarbons (PAHs) formed during biomass pyrolysis. Here, a novel Paenibacillus sp. was evaluated for its ability to degrade phytosterols in tobacco waste extract (TWE). The optimal conditions for cell growth and stigmasterol (a representative of phytosterols) degradation were 37 °C, pH 7.0, 1.0 g/L yeast extract, and 6.0 g/L glucose. Paenibacillus sp. could degrade stigmasterol under high concentrations of glucose (up to 130 g/L) and tolerate wide pH (5.0-9.0) and temperature (25-42 °C) ranges. The new strain could degrade stigmasterol completely into CO 2 and H 2 O, and no intermediate steroids were detected during the degradation process. Phytosterol degradation in TWE was demonstrated by high-performance liquid chromatography-tandem mass spectrometry. Under optimal conditions (37 °C, pH 7.0, with the exponential-phase cells), the total degradation ratio of phytosterols reached 38.5% in TWE, including 45.2% of stigmasterol, 37.4% of β-sitosterol, 27.3% of campesterol, and 28.7% of cholesterol. These results showed that Paenibacillus sp. is a candidate for phytosterol degradation in TWE and other biomass and is potentially useful in reducing the PAHs generated from biomass pyrolysis. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  17. Non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.

    Science.gov (United States)

    Pineda, Ana; Soler, Roxina; Weldegergis, Berhane T; Shimwela, Mpoki M; VAN Loon, Joop J A; Dicke, Marcel

    2013-02-01

    Beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it remains unknown how plants mediate the interactions between soil microbes and carnivorous insects, that is, the third trophic level. Using Arabidopsis thaliana Col-0 and the aphid Myzus persicae, we evaluate here the underlying mechanisms involved in the plant-mediated interaction between the non-pathogenic rhizobacterium Pseudomonas fluorescens and the parasitoid Diaeretiella rapae, by combining ecological, chemical and molecular approaches. Rhizobacterial colonization modifies the composition of the blend of herbivore-induced plant volatiles. The volatile blend from rhizobacteria-treated aphid-infested plants is less attractive to an aphid parasitoid, in terms of both olfactory preference behaviour and oviposition, than the volatile blend from aphid-infested plants without rhizobacteria. Importantly, the effect of rhizobacteria on both the emission of herbivore-induced volatiles and parasitoid response to aphid-infested plants is lost in an Arabidopsis mutant (aos/dde2-2) that is impaired in jasmonic acid production. By modifying the blend of herbivore-induced plant volatiles that depend on the jasmonic acid-signalling pathway, root-colonizing microbes interfere with the attraction of parasitoids of leaf herbivores. © 2012 Blackwell Publishing Ltd.

  18. Isolamento de esporos de Paenibacillus larvae subsp. larvae no Brasil Detectionof Paenibacillus larvae subsp. larvae spores in Brazil

    Directory of Open Access Journals (Sweden)

    Dulce Maria Tocchetto Schuch

    2003-03-01

    Full Text Available Este trabalho objetivou detectar presença de esporos de Paenibacillus larvae subsp. larvae em produtos de um entreposto do interior do Estado do Rio Grande do Sul, a identificação de possíveis fontes de contaminação e a avaliação da possibilidade da transferência de esporos para colméias de apiários adjacentes a partir de produtos importados contaminados. Foram analisados mel e pólen importados disponíveis no entreposto, favo do ninho (crias, pólen e mel colhido de uma colméia sadia, mel estocado em um dos apiários e abelhas adultas. Os resultados foram positivosem relação ao mel e pólen importados, a três grupos de abelhas adultas e ao mel do favo.The objective of this work was to detect the presence of Paenibacillus larvae subsp. larvae spores in products from a warehouse located in Rio Grande do Sul State, Brazil, the identification of possible contamination sources, and the assessment of spores transference possibility from contaminated imported products from the warehouse to apiaries located in the surrounding area. Samples of imported pollen and bulk honey stocked in the warehouse, and honeycomb (brood, honey and pollen from a healthy hive, honey from one apiary and adult bees were analyzed. Imported honey and pollen, and three groups of adult bees and the honey collected from the honeycomb resulted positive.

  19. Integrated use of plant growth promoting rhizobacteria, biogas slurry and chemical nitrogen for sustainable production of maize under salt-affected conditions

    International Nuclear Information System (INIS)

    Ahmad, M.; Jamil, M.; Akhtar, F.U.Z.

    2014-01-01

    Salinity is one of the most critical constraints hampering agricultural production throughout the world, including Pakistan. Some plant growth promoting rhizobacteria (PGPR) have the ability to reduce the deleterious effect of salinity on plants due to the presence of ACC-deaminase enzyme along with some other mechanisms. The integrated use of organic, chemical and biofertilizers can reduce dependence on expensive chemical inputs. To sustain high crop yields without deterioration of soil fertility, it is important to work out optimal combination of chemical and biofertilizers, and manures in the cropping system. A pot trial was conducted to study the effect of integrated use of PGPR, chemical nitrogen, and biogas slurry for sustainable production of maize under salt-stressed conditions and for good soil health. Results showed that sole application of PGPR, chemical nitrogen and biogas slurry enhanced maize growth but their combined application was more effective. Maximum improvement in maize growth, yield, ionic concentration in leaves and nutrient concentration in grains was observed in the treatment where PGPR and biogas slurry was used in the presence of 100% recommended nitrogen as chemical fertilizer. It also improved the soil pH, ECe, and available N, P and K contents. It is concluded that integrated use of PGPR, biogas slurry and chemical nitrogen not only enhanced maize growth, yield and quality but also improved soil health. So, it may be evaluated under field conditions to get sustained yield of maize from salt-affected soils. (author)

  20. Rizobactérias no crescimento e na produtividade da cebola Rhizobacteria on the production and yield of onion

    Directory of Open Access Journals (Sweden)

    Oscar Emilio Ludtke Harthmann

    2010-02-01

    Full Text Available A associação de plantas com rizobactérias pode promover o crescimento vegetal, reduzindo custos de produção. As rizobactérias benéficas podem ser uma alternativa para a produção de cebola. Neste trabalho, foi avaliado o efeito da aplicação de rizobactérias no crescimento e na produtividade da cebola da cultivar 'Bola Precoce'. A aplicação foi realizada na Estação Experimental da Epagri, em Ituporanga, Santa Catarina (SC, no ano de 2008. O delineamento experimental foi em blocos ao acaso, com cinco repetições, sendo utilizadas as rizobactérias Pseudomonas spp. W6, Bacillus megaterium W19 e Bacillus cereus UFV40, microbiolizadas isoladamente nas sementes ou em mistura, juntamente com uma testemunha não tratada. Os tratamentos com aplicação de rizobactérias proporcionaram maior altura, diâmetro de pseudocaule e número de folhas nas plantas avaliadas aos 90 dias após o transplante. Plantas que receberam os tratamentos com rizobactérias apresentaram maior rendimento de bulbos em relação à testemunha. A massa dos bulbos foi afetada positivamente pelos tratamentos, com destaque para Bacillus megaterium W19.The association of plants with rhizobacteria can enhance plant growth, reducing production costs. Benefic rhizobacteria can stimulate plant growth being an alternative for production of onions. This research assesses the impact of applying rhizobacteria in the growth and productivity of cv. Bola Precoce onions. The study was conducted in the Experimental Station of Epagri, Ituporanga, SC, Brazil in 2008. The experimental design was in random blocks with five repetitions using Pseudomonas spp. W6, B Bacillus megaterium W19 e Bacillus cereus UFV40 rhizobacteria, microbiolized singly in seeds or in a formula together with non-treated control. The treatments involving rhizobacteria application yielded higher heights, diameter of pseudo-trunk and number of leaves in the plants assessed at 90 days after transplant. All the

  1. Paenibacillus solanacearum sp. nov., isolated from rhizosphere soil of a tomato plant.

    Science.gov (United States)

    Cho, Hayoung; Heo, Jun; Ahn, Jae-Hyung; Weon, Hang-Yeon; Kim, Jeong-Seon; Kwon, Soon-Wo; Kim, Soo-Jin

    2017-12-01

    The taxonomic position of a bacterial strain designated T16R-228 T , isolated from a rhizosphere soil sample of a tomato plant collected from a farm in Buyeo, Chungcheongnam-do, Republic of Korea, was determined using a polyphasic approach. On the basis of morphological, genetic and chemotaxonomic characteristics, it was determined to belong to the genus Paenibacillus. It was an aerobic, Gram-stain-positive, non-motile, catalase-negative, oxidase-negative rod with peritrichous flagella. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, hydroxyl- phosphatidylethanolamine and one unidentified polar lipid. Menaquiones were MK-7. Predominant cellular fatty acids were anteiso-C15 : 0, C16 : 0 and iso-C16 : 0. DNA G+C content was 56.8 mol%. The phylogenetic tree constructed based on the 16S rRNA gene sequences showed the strain formed a clade with P. mucilaginosus VKPM B-7519 T , P. edaphicus T7 T , P. ehimensis KCTC 3748 T , P. koreensis YC300 T , P. tianmuensis B27 T and P. elgii SD17 T , showing the highest sequence similarity with P. mucilaginosus VKPM B-7519 T (96.5 %). The polyphasic data supported that strain T16R-228 T was clearly distinguished from its closely related species and represents a novel species of the genus Paenibacillus for which the name Paenibacillus solanacearum is proposed. The type strain is T16R-228 T (=KACC 18654 T =NBRC 111896 T ).

  2. Incidence of root rot diseases of soybean in Multan Pakistan and its management by the use of plant growth promoting rhizobacteria

    International Nuclear Information System (INIS)

    Haq, M.I.; Tahir, M.I.; Mahmood, S.

    2012-01-01

    Eight villages in Multan district were surveyed to record incidence of disease and losses of soybean (Glycine max L.) caused by root rot fungi. The root incidence ranged 10-17% and losses ranged 6.75-15.5%. The evaluation of four PGPR isolates was used in combination with organic amendment for the management of root-rot disease incidence and to reduce the population of root pathogenic fungi and to increase the yield in field. This study demonstrated effective biological control by the PGPR isolates tested, thereby indicating the possibility of application of rhizobacteria for control of soil bor ne diseases of soybean in Pakistan and other countries. (author)

  3. Phytoremediation of mercury in pristine and crude oil contaminated soils: Contributions of rhizobacteria and their host plants to mercury removal.

    Science.gov (United States)

    Sorkhoh, N A; Ali, N; Al-Awadhi, H; Dashti, N; Al-Mailem, D M; Eliyas, M; Radwan, S S

    2010-11-01

    The rhizospheric soils of three tested legume crops: broad beans (Vicia faba), beans (Phaseolus vulgaris) and pea (Pisum sativum), and two nonlegume crops: cucumber (Cucumis sativus) and tomato, (Lycopersicon esculentum) contained considerable numbers (the magnitude of 10(5)g(-1) soil) of bacteria with the combined potential for hydrocarbon-utilization and mercury-resistance. Sequencing of the 16S rRNA coding genes of rhizobacteria associated with broad beans revealed that they were affiliated to Citrobacter freundii, Enterobacter aerogenes, Exiquobacterium aurantiacum, Pseudomonas veronii, Micrococcus luteus, Brevibacillus brevis, Arthrobacter sp. and Flavobacterium psychrophilum. These rhizobacteria were also diazotrophic, i.e. capable of N(2) fixation, which makes them self-sufficient regarding their nitrogen nutrition and thus suitable remediation agents in nitrogen-poor soils, such as the oily desert soil. The crude oil attenuation potential of the individual rhizobacteria was inhibited by HgCl(2), but about 50% or more of this potential was still maintained in the presence of up to 40 mgl(-1) HgCl(2). Rhizobacteria-free plants removed amounts of mercury from the surrounding media almost equivalent to those removed by the rhizospheric bacterial consortia in the absence of the plants. It was concluded that both the collector plants and their rhizospheric bacterial consortia contributed equivalently to mercury removal from soil. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Using Real-time PCR for Identification of Paenibacillus larvae

    Directory of Open Access Journals (Sweden)

    Vladimíra Kňazovická

    2011-05-01

    Full Text Available The aim of the study was identification of Paenibacillus larvae that causes American foulbrood disease (AFB in colony of bees (Apis mellifera. Bacterial isolates originated from honey samples, because presence of P. larvae in honey is treated as early diagnostic of AFB. Intense proteolytic activity and no catalase activity are typical for Gram positive rod-shaped bacteria P. larvae. We diluted honey (1:2, heated at 80 °C for 10 min and inoculated on semiselective medium MYPGP agar with nalidixic acid. Plates were cultivated at 37 °C for 48 – 72 h under the aerobic conditions. Selected colonies were transferred on MYT agar and cultivated 24 h. We analysed 30 honey samples and found 27 bacterial isolates. All isolates were Gram positive and mainly rod-shaped. No catalase activity was documented for 6 from 27 isolates. Identification was finished by real-time PCR to detect the 16S rRNA gene of Paenibacillus larvae with real-time cycler Rotor-Gene 6000. As DNA template we used genomic DNA isolated with commercial kit and DNA lysate obtaining by boiled cells. We used 2 strains of P. larvae from CCM (Czech Collection of Microorganisms as positive control. The reliable method of detection P. larvae has important rule for beekeeping.

  5. Screening and characterization of endophytic Bacillus and Paenibacillus strains from medicinal plant Lonicera japonica for use as potential plant growth promoters

    Directory of Open Access Journals (Sweden)

    Longfei Zhao

    2015-12-01

    Full Text Available Abstract A total of 48 endophytic bacteria were isolated from surface-sterilized tissues of the medicinal plant Lonicera japonica, which is grown in eastern China; six strains were selected for further study based on their potential ability to promote plant growth in vitro (siderophore and indoleacetic acid production. The bacteria were characterized by phylogenetically analyzing their 16S rRNA gene similarity, by examining their effect on the mycelial development of pathogenic fungi, by testing their potential plant growth-promoting characteristics, and by measuring wheat growth parameters after inoculation. Results showed that the number of endophytic bacteria in L. japonica varied among different tissues, but it remained relatively stable in the same tissues from four different plantation locations. Among the three endophytic strains, strains 122 and 124 both had high siderophore production, with the latter showing the highest phosphate solubilization activity (45.6 mg/L and aminocyclopropane-1-carboxylic acid deaminase activity (47.3 nmol/mg/h. Strain 170 had the highest indoleacetic acid (IAA production (49.2 mg/L and cellulase and pectinase activities. After inoculation, most of the six selected isolates showed a strong capacity to promote wheat growth. Compared with the controls, the increase in the shoot length, root length, fresh weight, dry weight, and chlorophyll content was most remarkable in wheat seedlings inoculated with strain 130. The positive correlation between enzyme (cellulose and pectinase activity and inhibition rate on Fusarium oxysporum, the IAA production, and the root length of wheat seedlings inoculated with each tested endophytic strain was significant in regression analysis. Deformity of pathogenic fungal mycelia was observed under a microscope after the interaction with the endophytic isolates. Such deformity may be directly related to the production of hydrolytic bacterial enzymes (cellulose and pectinase. The six

  6. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds

    NARCIS (Netherlands)

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M.; Park, Kyungseok

    2015-01-01

    Abstract Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens

  7. Genome-based comparative analyses of Antarctic and temperate species of Paenibacillus.

    Directory of Open Access Journals (Sweden)

    Melissa Dsouza

    Full Text Available Antarctic soils represent a unique environment characterised by extremes of temperature, salinity, elevated UV radiation, low nutrient and low water content. Despite the harshness of this environment, members of 15 bacterial phyla have been identified in soils of the Ross Sea Region (RSR. However, the survival mechanisms and ecological roles of these phyla are largely unknown. The aim of this study was to investigate whether strains of Paenibacillus darwinianus owe their resilience to substantial genomic changes. For this, genome-based comparative analyses were performed on three P. darwinianus strains, isolated from gamma-irradiated RSR soils, together with nine temperate, soil-dwelling Paenibacillus spp. The genome of each strain was sequenced to over 1,000-fold coverage, then assembled into contigs totalling approximately 3 Mbp per genome. Based on the occurrence of essential, single-copy genes, genome completeness was estimated at approximately 88%. Genome analysis revealed between 3,043-3,091 protein-coding sequences (CDSs, primarily associated with two-component systems, sigma factors, transporters, sporulation and genes induced by cold-shock, oxidative and osmotic stresses. These comparative analyses provide an insight into the metabolic potential of P. darwinianus, revealing potential adaptive mechanisms for survival in Antarctic soils. However, a large proportion of these mechanisms were also identified in temperate Paenibacillus spp., suggesting that these mechanisms are beneficial for growth and survival in a range of soil environments. These analyses have also revealed that the P. darwinianus genomes contain significantly fewer CDSs and have a lower paralogous content. Notwithstanding the incompleteness of the assemblies, the large differences in genome sizes, determined by the number of genes in paralogous clusters and the CDS content, are indicative of genome content scaling. Finally, these sequences are a resource for further

  8. Molecular Characterization of the Plant Growth Promoting Bacterium Enterobacter sp. SA187 upon Contact with Arabidopsis thaliana

    KAUST Repository

    Alsharif, Wiam

    2018-01-01

    Salt stress is a severe environmental challenge in agriculture, limiting the quality and productivity of the crops around the globe. Plant growth promoting rhizobacteria (PGPR) is proposed as a friendly solution to overcome those challenges

  9. Identification and Structural Characterization of Naturally-Occurring Broad-Spectrum Cyclic Antibiotics Isolated from Paenibacillus

    Science.gov (United States)

    Knolhoff, Ann M.; Zheng, Jie; McFarland, Melinda A.; Luo, Yan; Callahan, John H.; Brown, Eric W.; Croley, Timothy R.

    2015-08-01

    The rise of antimicrobial resistance necessitates the discovery and/or production of novel antibiotics. Isolated strains of Paenibacillus alvei were previously shown to exhibit antimicrobial activity against a number of pathogens, such as E. coli, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA). The responsible antimicrobial compounds were isolated from these Paenibacillus strains and a combination of low and high resolution mass spectrometry with multiple-stage tandem mass spectrometry was used for identification. A group of closely related cyclic lipopeptides was identified, differing primarily by fatty acid chain length and one of two possible amino acid substitutions. Variation in the fatty acid length resulted in mass differences of 14 Da and yielded groups of related MSn spectra. Despite the inherent complexity of MS/MS spectra of cyclic compounds, straightforward analysis of these spectra was accomplished by determining differences in complementary product ion series between compounds that differ in molecular weight by 14 Da. The primary peptide sequence assignment was confirmed through genome mining; the combination of these analytical tools represents a workflow that can be used for the identification of complex antibiotics. The compounds also share amino acid sequence similarity to a previously identified broad-spectrum antibiotic isolated from Paenibacillus. The presence of such a wide distribution of related compounds produced by the same organism represents a novel class of broad-spectrum antibiotic compounds.

  10. Antifungal activity of plant growth-promoting rhizobacteria isolates ...

    African Journals Online (AJOL)

    Seven plant growth-promoting rhizobacterial (PGPR) strains were isolated from the rhizoplane and rhizosphere of wheat from four different sites of Pakistan. These strains were analyzed for production of indole acetic acid (IAA), phosphorous solublization capability and inhibition of Rhizoctonia solani on rye agar medium.

  11. Antibacterial Activity of Different Plant Extracts and Phenolic Phytochemicals Tested on Paenibacillus Larvae Bacteria

    Directory of Open Access Journals (Sweden)

    Liviu Mărghitaş

    2011-10-01

    Full Text Available Paenibacillus larvae, a Gram-positive and spore-forming bacterium is responsible for American foulbrood disease inbees. The antimicrobial activity of different plant extracts and phenolic phytochemical was evaluated onPaenibacillus larvae bacteria. In addition possible correlation with antioxidant activity of the same plant extracts wasstudied. Extracts of the following plants were utilized: Achillea millefolium (yarrow, Ocimum basilicum (basil,Thymus vulgaris (thyme and Urtica dioica (nettle. The extracts that showed antimicrobial activity were later testedto determine the Minimal Inhibitory Concentration (MIC. Although nettle present the lowest polyphenolic contentcompared with the other plant extracts, exhibit the highest antimicrobial activity, measured as the inhibition zoneusing Mueller-Hinton agar plates. Basil presented both polyphenolic content and antimicrobial activity at higherlevels, while thyme had the lowest antimicrobial activity, even it present high amount of polyphenols.

  12. Diversity and Plant Growth Promoting Proerties of Rhizobacteria ...

    African Journals Online (AJOL)

    The purpose of this study was to evaluate and assess the plant growth promoting characteristics and diversity of major tef rhizosphere isolates from central Ethiopia. A total of 162 bacteria were isolated from rhizosphere of tef [Eragrostis tef (Zucc.) Trotter] and characterized. While screening using some plant growth ...

  13. Novel structural features of xylanase A1 from Paenibacillus sp. JDR-2

    Science.gov (United States)

    Franz J. St John; James F. Preston; Edwin Pozharski

    2012-01-01

    The Gram-positive bacterium Paenibacillus sp. JDR-2 (PbJDR2) has been shown to have novel properties in the utilization of the abundant but chemically complex hemicellulosic sugar glucuronoxylan. Xylanase A1 of PbJDR2 (PbXynA1) has been implicated in an efficient process in which extracellular...

  14. Rizobactérias e promoção do crescimento de plantas cítricas Rhizobacteria and growth promotion of citrus plants

    Directory of Open Access Journals (Sweden)

    S. S. Freitas

    2004-12-01

    Full Text Available Desenvolveram-se três experimentos em casa de vegetação para verificar a possibilidade de as rizobactérias atuarem como promotoras do crescimento de plantas cítricas. Ao todo, testaram-se 10 isolados de Pseudomonas do grupo fluorescente, 13 de Bacillus e sete de outras bactérias rizosféricas em porta-enxertos utilizados na citricultura: tangerineira 'Cleópatra' (Citrus reshni, limoeiro 'Cravo' (Citrus limonia e limoeiro 'Volcameriano' (Citrus volkameriana. Dependendo do porta-enxerto, sete isolados de Pseudomonas, um de Bacillus e um de outra bactéria rizosférica tiveram efeito benéfico sobre a matéria seca de raízes ou de parte aérea, indicando uma alta proporção de promotores de crescimento entre as bactérias do primeiro grupo. Procedeu-se também à contagem de bactérias fluorescentes do gênero Pseudomonas e de bactérias não-fluorescentes em raízes de tangerineira 'Cleópatra' e de limoeiro 'Cravo', procedentes de viveiro de mudas e do campo. Ambos os grupos bacterianos tiveram sua multiplicação favorecida na rizosfera de tangerineira 'Cleópatra', em condições de viveiro.Three greenhouse trials were carried out to verify if rhizobacteria can promote citrus plant growth. Ten isolates of fluorescent Pseudomonads, thirteen of Bacillus spp. and seven of other rhizospheric bacteria were tested in three rootstocks seedlings: 'Cleopatra' mandarin (Citrus reshni, rangpure lime (Citrus limonia and Volkamerian lemon (Citrus volkameriana. Depending on the rootstock, seven Pseudomonads, one isolate of Bacillus and one of other rhizospheric bacteria increased the root or shoot dry weight, indicating a high proportion of growth promoters among the fluorescent Pseudomonads. Also, fluorescent Pseudomonads and non fluorescent bacteria were counted in the roots of nursery seedlings and field plants of Citrus reshni and Citrus limonia. The growth of both bacterial groups was favored in the Citrus reshni rhizosphere under nursery

  15. Use of Bacillus pumilus CBMAI 0008 and Paenibacillus sp. CBMAI 868 for colour removal from paper mill effluent Emprego de Bacillus pumilus CBMAI 0008 e Paenibacillus sp. CBMAI 868 para remoção da cor do efluente da indústria papeleira

    Directory of Open Access Journals (Sweden)

    Patrícia Lopes de Oliveira

    2009-06-01

    Full Text Available Bacillus pumilus and Paenibacillus sp. were applied on the paper mill effluent to investigate the colour remotion. Inocula were individually applied in effluent at pH 7.0, 9.0 and 11.0. The real colour and COD remotion after 48h at pH 9.0 were, respectively, 41.87% and 22.08% for B. pumilus treatment and 42.30% and 22.89% for Paenibacillus sp. Gel permeation chromatography was used to verify the molar masses of compounds in the non-treated and treated effluent, showing a decrease in the compounds responsible for the paper mill effluent colour.Bacillus pumilus e Paenibacillus sp. foram aplicados separadamente no efluente da indústria papeleira a pH 7,0, 9,0 e 11,0, para verificação da remoção da cor e da DQO. As remoções da cor real e DQO após 48h a pH 9,0 foram, respectivamente, de 41,87% e 22,08% após o tratamento com B. pumilus e 42,30% e 22,89% após tratamento com Paenibacillus sp. As massas molares dos compostos presentes no efluente não tratado e tratado foram determinadas por cromatografia de permeação em gel. O emprego dos microrganismos reduziu os compostos responsáveis pela cor do efluente da indústria papeleira.

  16. Characterization of four Paenibacillus species isolated from pasteurized, chilled ready-to-eat meals

    NARCIS (Netherlands)

    Helmond, Mariette; Nierop Groot, Masja N.; Bokhorst-van de Veen, van Hermien

    2017-01-01

    Food spoilage is often caused by microorganisms. The predominant spoilage microorganisms of pasteurized, chilled ready-to-eat (RTE) mixed rice-vegetable meals stored at 7 °C were isolated and determined as Paenibacillus species. These sporeforming psychrotrophic bacteria are well adapted to grow

  17. Study of Plant Growth Promoting Rhizobacteria (PGPR and Drought on Physiological Traits and Ultimate Yield of Cultivars of Oilseed Rape (Brassica spp. L.

    Directory of Open Access Journals (Sweden)

    pooya arvin

    2018-02-01

    Full Text Available Introduction Oilseed rape (Brassica spp L. is one of the valuable oilseed crops which has been attracting attention in recent years. Iran is located in a semi-arid region, and water shortage has caused problems, namely providing drinking water as much as water supply for crop production. Not only does Plant Growth Promoting Rhizobacteria (PGPR make plant growth stimulating hormones like Auxin and Gibberellin but also can ease stress conditions by producing ABA. Consequently, considering the current water shortage crisis in Iran, we took three main criteria into account: the roles of PGPRs in increasing resistance to abiotic stress, relief of drought effects, and the importance of cultivation of oilseed rape. The present research has been compiled to study drought and some Plant Growth Promoting Rhizobacteria (PGPR on Physiological Traits and Ultimate Yield of Cultivars of Oilseed Rape. Materials and Methods The current study was done on the basis of two simultaneous experiments (under stress and non-stress experiments during 2010- 2011 growing season at Agriculture and Natural Resources Research Station of Torogh, Mashhad is situated in East-North of Iran (36° N, 59° E, 1003 ASL . Two research sites (under stress and no-stress fields were selected beside each other. This region has a semi-arid climate (annual rainfall 286 mm. The experimental design was factorial based on randomized completely block design with three replications in each experiment. The first treatment was Plant Growth Promoting Rizobactria, including B0: no inoculation (control, B1: co-inoculation (Pseudomonas flourescens 169+P. putida 108, B2: inoculation with P. flourescens 169 and B3: inoculation with P. putida 108. Second treatment was cultivar, including Hayola401 and Hayola330 cultivars belong to Brassica napus, Parkland and Goldrush cultivars belong to B. rapa and BP18 and landrace cultivars belong to B.juncea .Greenness index, plant height, relative water content

  18. Rhizobacterial characterization for quality control of eucalyptus biogrowth promoter products

    Directory of Open Access Journals (Sweden)

    Talyta Galafassi Zarpelon

    Full Text Available Abstract Plant growth-promoting rhizobacteria strains from special formulations have been used to optimize eucalyptus cutting production. To undertake quality control for the formulated products, the rhizobacterial strains should be characterized to assess their purity and authentication. In the present study, we characterized nine strains of rhizobacteria, including three Bacillus subtilis (S1, S2 and 3918, two Pseudomonas sp. (MF4 and FL2, P. putida (MF2, P. fulva (Ca, Frateuria aurantia (R1, and Stenotrophomonas maltophilia (CIIb. The strains were differentiated by colony morphology after 24 h of incubation in three different solid state culture media (glucose-nutritive agar, 523 medium and yeast extract-mannitol agar, sensitivity to a panel of 28 antibiotics (expressed according to the formation of inhibition halos of bacterial growth in the presence of antibiotics, and PCR-RFLP profiles of the 16S rDNA gene produced using nine restriction enzymes. It was possible to differentiate all nine strains of rhizobacteria using their morphological characteristics and sensitivity to antibiotics. The molecular analysis allowed us to separate the strains CIIb, FL2 and R1 from the strains belonging to the genera Bacillus and Pseudomonas. By using these three methods concomitantly, we were able to determine strain purity and perform the authentication.

  19. Purification and Characterization of Exo-Inulinase from Paenibacillus sp. d9 Strain.

    Science.gov (United States)

    Jeza, S; Maseko, S B; Lin, J

    2018-02-01

    This study intended to purify and characterise exo-inulinase of diesel-degrading Paenibacillus sp. D9. The whole genome sequencing of Paenibacillus sp. D9 revealed to possess the sacC gene that is encoded as exo-inulinase/levanase. This isolate was capable of producing a maximum of 50.9 IU/mL of exo-inulinase activity within 3 days at 30 °C, 200 rpm and pH of 7.0 on minimal salt medium agar supplemented with 1% (w/v) inulin. An exo-inulinase of 58.5 kDa was purified using ammonium sulphate precipitation, HiTrap QFF column and MMC column chromatographies with a specific activity of 4333 IU/mg, 7.1% recovery and a 4.3-fold increase in purity. The purified D9 exo-inulinase had temperature and pH optimum at 40 °C and pH 4.0, respectively, with the Michaelis constant of 5.5 mM and a maximal velocity of 476.2 IU/mg, respectively. Catalytic constant, k cat was calculated to be 42.6 s -1 with a catalytic efficiency (k cat /K m ) of 7.6 s -1  mM -1 . The presence of Ca 2+ enhanced the activity of D9 exo-inulinase while Hg 2+ completely inhibited the activity, other compounds such as Fe 3+ and Cu 2+ had an inhibitory effect. The results of amino acid alignment and the complete degradation of inulin into fructose by the purified enzyme confirmed that inulinase from Paenibacillus sp. D9 is an exo-form. The phylogenetic tree based on the protein sequences indicates that bacterial exo-inulinases possess a common ancestry.

  20. Novel pyrazine metabolites found in polymyxin biosynthesis by Paenibacillus polymyxa

    DEFF Research Database (Denmark)

    Beck, Hans Christian; Hansen, Anne M; Lauritsen, Frants R

    2003-01-01

    A complex mixture of methyl-branched alkyl-substituted pyrazines was found in the growth medium of the polymyxin-producing bacterium Paenibacillus polymyxa, and of these, seven are new natural compounds. A total of 19 pyrazine metabolites were identified. The dominant metabolite was 2...... supplementation. The other pyrazine metabolites, all related pyrazines with either one, two or three alkyl substituents, were identified by means of their mass spectral data and/or co-elution with authentic standards....

  1. New approach for dry formulation techniques for rhizobacteria

    Science.gov (United States)

    Elchin, A. A.; Mashinistova, A. V.; Gorbunova, N. V.; Muratov, V. S.; Kydralieva, K. A.; Jorobekova, Sh. J.

    2009-04-01

    Two beneficial Pseudomonas isolates selected from rhizosphere of abundant weed - couch-grass Elytrigia repens L. Nevski have been found to have biocontrol activity. An adequate biocontrol effect requires high yield and long stability of the bacterial preparation [1], which could be achieved by an effective and stable formulation. This study was aimed to test various approaches to dry formulation techniques for Pseudomonas- based preparations. To reach this goal, two drying formulation techniques have been tested: the first one, spray drying and the second, low-temperature contact-convective drying in fluidized bed. The optimal temperature parameters for each technique were estimated. Main merits of the selected approach to dry technique are high yield, moderate specific energy expenditures per 1 kg of evaporated moisture, minimal time of contact of the drying product with drying agent. The technological process for dry formulation included the following stages: the obtaining of cell liquids, the low-temperature concentrating and the subsequent drying of a concentrate. The preliminary technological stages consist in cultivation of the rhizobacteria cultures and concentrating the cell liquids. The following requirements for cultivation regime in laboratory conditions were proposed: optimal temperatures are 26-28°С in 3 days, concentration of viable cells in cell liquid makes 1010-1011 cell/g of absolutely dry substance (ADS). For concentrating the cell liquids the method of a vacuum evaporation, which preserves both rhizobacteria cells and the secondary metabolites of cell liquid, has been used. The process of concentrating was conducted at the minimum possible temperature, i.e. not above 30-33°С. In this case the concentration of viable cells has decreased up to 109-1010 cell/g of ADS. For spray drying the laboratory up-dated drier BUCHI 190, intended for the drying of thermolabile products, was used. The temperatures of an in- and outcoming air did not exceed

  2. PHOSPHATE-SOLUBILISING RHIZOBACTERIA ASSOCIATED WITH PHASEOLUS COCCINEUS L. RHIZOSPHERE

    Directory of Open Access Journals (Sweden)

    Marius Stefan

    2012-10-01

    Full Text Available Native phosphate solubilizing bacteria were isolated from runner bean rhizosphere in order to study their effect on releases of soluble phosphorus from inorganic P sources. 34.37% of the rhizobacteria isolates solubilized CaHPO4 in the qualitative P-solubilization plate method after seven days of incubation. The best PSB isolates were selected for further study concerning P-solubilization in liquid culture. All these isolates showed higher potential for solubilization of inorganic P as indicated by the increase of P amount in the RPAM medium. Our results showed that PSB strains play a significant role in the acidification of the medium facilitating the P solubilization probably due to organic acid production.

  3. Effect of Plant Growth Promoting Rhizobacteria (PGPR on Yield and Yield Components of Sesame (Sesamum indicum l. with Emphasize on Environmental Friendly Operations

    Directory of Open Access Journals (Sweden)

    P Rezvani Moghaddam

    2015-07-01

    Full Text Available In order to evaluate the effects of different plant growth promoting rhizobacteria (PGPR on yield and yield components of sesame, an experiment was conducted in the form of Randomized Complete Block Design with three replications at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad in year 2009. Treatments were: 1 Nitragin (containing of Azotobacter sp., Azospirillum sp. and Pseudomonas sp., 2 Nitroxin (containing of Azotobacter sp. and Azospirillum sp., 3 Super nitro plus (containing of Azospirillum sp., Bacillus sp. and Pseudomonas sp., 4 Phosphate suloblizing bacteria (containing of Bacillus sp. and Pseudomonas sp., 5 Bio Phosphate (containing of Bacillus sp. and Pseudomonas sp., 6 Nitroxin + Phosphate suloblizing bacteria, 7 Nitroxin + Bio Phosphate and control. The results showed that seed yield affected by PGPR and Nitroxin + Phosphate suloblizing bacteria treatment had superior effect on seed yield compared to other treatments. Superior effect of Nitroxin + Phosphate suloblizing bacteria treatment also was shown on plant seed weight and harvest index. Nitragin, Nitroxin + Bio Phosphate, Nitroxin + Phosphate suloblizing bacteria, Bio Phosphate, Phosphate suloblizing bacteria, Nitroxin treatments increased dry weight of capsules per plant of 62, 53, 51, 36 and 30 percent compared to control, respectively. Although, the effect of PGPR was not significant on sesame seed oil content but Bio Phosphate and Nitragin treatments increased seed oil content by 1 and 1.5 percent, respectively. In general, results showed utilization of PGPR can improve seed yield and seed oil content, which can decrease dependence of sesame seed production to chemical fertilizer, decrease negative environmental impacts and as an ecofriendly inputs can help to produce crops and sustainable agriculture guidlines.

  4. Paenibacillus brasilensis sp nov., a novel nitrogen-fixing species isolated from the maize rhizosphere in Brazil

    NARCIS (Netherlands)

    Weid, von der I.; Duarte, G.F.; Elsas, van J.D.; Seldin, L.

    2002-01-01

    Sixteen nitrogen-fixing strains isolated from the rhizosphere of maize planted in Cerrado soil, Brazil, which showed morphological and biochemical characteristics similar to the gas-forming Paenibacillus spp., were phenotypically and genetically characterized. Their identification as members of the

  5. Radiosensitivity of spores of Paenibacillus larvae ssp. larvae in honey

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Wanderley Mendes de [Ministerio da Agricultura, Pecuaria e Abastecimento, Rio de Janeiro, RJ (Brazil). Servico de Inspecao de Produtos de Origem Animal]. E-mail: sipa-rj@agricultura.gov.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito CTEx, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Schuch, Dulce Maria Tocchetto [Ministerio da Agricultura, Pecuaria e Abastecimento, Porto Alegre, RS (Brazil)]. E-mail: micro-lara-rs@agricultura.gov.br

    2007-07-01

    Irradiation, usually used in combination with other conventional methods of conservation, has been proven to be an efficient tool to ensure the safety of many types of foods by destroying pathogenic microorganisms and extending their shelf-lives. This work has investigated the efficacy of gamma irradiation to inactivate spores of the bacterium Paenibacillus larvae that causes the 'American foulbrood', a highly contagious disease still exotic in Brazil that kills bees and contaminates honey, preventing its commercialization and causing great economical losses. In this study, 60 g samples of two types of honey inoculated with 3.5x10{sup 3} spores/mL of that bacterium were irradiated with doses of 0, 5, 7.5, 10, 12.5 and 15 kGy and counted. The analyses indicated a mean reduction of 97.5{+-}0.7% in the number of viable spores exposed to 5 kGy. The application of doses of 7.5 kGy or higher yielded no viable spores above the detection threshold (10/mL). In addition the value of D{sub 10} (3.1{+-}0.3 kGy) was estimated and the logarithm of the population of viable spores of Paenibacillus larvae subsp. larvae was determined as linear and quadratic polynomial functions of the radiation dose. The results indicated that the dose of 10 kGy could be insufficient to assure complete sterilization of honey in some cases while suggesting that 25 kGy would perform such task adequately. (author)

  6. Diversity of Paenibacillus polymyxa strains isolated from the rhizosphere of maize planted in Cerrado soil

    NARCIS (Netherlands)

    Weid, von der I.; Paiva, E.; Nobrega, A.; Elsas, van J.D.; Seldin, L.

    2000-01-01

    Paenibacillus polymyxa populations present in the rhizosphere of maize (cultivar BR-201) planted in Cerrado soil were investigated in order to assess their diversity at four stages of plant growth. A total of 67 strains were isolated and all strains were identified as P. polymyxa by classical

  7. Effect of rhizobacteria inoculation and humic acid application on canola (Brassica napus L.) crop

    International Nuclear Information System (INIS)

    Ahmad, S.; Duar, I.; Solaimani, S.G.A.; Mahmood, S.

    2016-01-01

    This study investigated eco-friendly approach of utilizing plant growth promoting rhizobacteria (PGPR) and humic acid (HA) as bio-stimulants to improve the growth, yield and nutrition of canola (Brassica napus L.). In this study, we isolated 20 indigenous rhizobacterial strains that were subsequently screened and characterized for their plant growth promoting traits. After that one promising PGPR strain identified as Acinetobacter pittii by 16S rRNA gene sequencing was selected for field trial. The field experiment was conducted using RCB design with split-plot arrangement that was replicated four times. Three levels of humic acid (0, 10 and 20 kg ha-1) as main plot factor and two treatments of PGPR (with and without PGPR) as sub-plot factor were used. Data was recorded on plant height (cm), root dry matter plant-1, number of lateral root plant-1, number of pods plant-1, number of seeds pod-1, 1000 seed weight (g), seed yield(kg ha-1), oil content (%), nitrogen (N), phosphorus (P) and potassium (K) contents and uptake. For most of the above mentioned parameters, significant enhancement was observed with the increment of humic acid, and also PGPR treatments were better than their respective control treatments. Maximum values of these parameters were recorded for the interaction of 20 kg HA ha-1 with the PGPR strain. It can be concluded that integrated application of HA and PGPR is a better strategy to improve nutrition and yield of canola. (author)

  8. Oxidative Stress Induced by Polymyxin E Is Involved in Rapid Killing of Paenibacillus polymyxa

    Directory of Open Access Journals (Sweden)

    Zhiliang Yu

    2017-01-01

    Full Text Available Historically, the colistin has been thought to kill bacteria through membrane lysis. Here, we present an alternative mechanism that colistin induces rapid Paenibacillus polymyxa death through reactive oxygen species production. This significantly augments our understanding of the mechanism of colistin action, which is critical knowledge toward the yield development of colistin in the future.

  9. Non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.

    NARCIS (Netherlands)

    Pineda, A.; Soler Gamborena, R.; Weldegergis, B.T.; Shimwela, M.M.; Loon, van J.J.A.; Dicke, M.

    2013-01-01

    Beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it

  10. Biochar and flyash inoculated with plant growth promoting rhizobacteria act as potential biofertilizer for luxuriant growth and yield of tomato plant.

    Science.gov (United States)

    Tripti; Kumar, Adarsh; Usmani, Zeba; Kumar, Vipin; Anshumali

    2017-04-01

    Overuse of agrochemical fertilizers alarmingly causes deterioration in soil health and soil-flora. Persistence of these agrochemicals exerts detrimental effects on environment, potentially inducing toxic effects on human health, thus pronouncing an urgent need for a safer substitute. The present study investigates the potential use of agricultural and industrial wastes as carrier materials, viz. biochar and flyash, respectively, for preparation of bioformulations (or biofertilizers) using two plant growth promoting rhizobacteria, Bacillus sp. strain A30 and Burkholderia sp. strain L2, and its effect on growth of Lycopersicon esculentum Mill. (tomato). The viability of strains was determined based on colony forming units (cfu) count of each bioformulation at an interval of 60 days for a period of 240 days. Seeds were coated with different carrier based bioformulations and pot experiment(s) were carried out to access its effects on plant growth parameters. Biochar based bioformulations showed higher cfu count and maximum viability for strain L2 (10 7  cfu g -1 ) at 240 days of storage. Maximum percentage of seed germination was also observed in biochar inoculated with strain L2. Significant (p < 0.05) increase in plant growth parameters (dry and fresh biomass, length, number of flowers) were ascertained from the pot experiment and amongst all bioformulations, biochar inoculated with strain L2 performed consistently thriving results for tomato yield. Furthermore, post-harvest study of this bioformulation treated soil improved physico-chemical properties and dehydrogenase activity as compared to pre-plantation soil status. Overall, we show that prepared biochar based bioformulation using Burkholderia sp. L2 as inoculum can tremendously enhance the productivity of tomato, soil fertility, and can also act as a sustainable substitute for chemical fertilizers. In addition, mixture of biochar and flyash inoculated with strain L2 also showed noteworthy results for the

  11. Drought response of Mucuna pruriens (L. DC. inoculated with ACC deaminase and IAA producing rhizobacteria.

    Directory of Open Access Journals (Sweden)

    Aansa Rukya Saleem

    Full Text Available Drought is one of the major constraints limiting agricultural production worldwide and is expected to increase in the future. Limited water availability causes significant effects to plant growth and physiology. Plants have evolved different traits to mitigate the stress imposed by drought. The presence of plant growth-promoting rhizobacteria (PGPR could play an important role in improving plant performances and productivity under drought. These beneficial microorganisms colonize the rhizosphere of plants and increase drought tolerance by lowering ethylene formation. In the present study, we demonstrate the potential to improve the growth of velvet bean under water deficit conditions of two different strains of PGPR with ACCd (1-Aminocyclopropane-1-Carboxylate deaminase activity isolated from rainfed farming system. We compared uninoculated and inoculated plants with PGPR to assess: a photosynthetic performance and biomass; b ACC content and ethylene emission from leaves and roots; c leaf isoprene emission. Our results provided evidence that under drought conditions inoculation with PGPR containing the ACCd enzyme could improve plant growth compared to untreated plants. Ethylene emission from roots and leaves of inoculated velvet bean plants was significantly lower than uninoculated plants. Moreover, isoprene emission increased with drought stress progression and was higher in inoculated plants compared to uninoculated counterparts. These findings clearly illustrate that selected PGPR strains isolated from rainfed areas could be highly effective in promoting plant growth under drought conditions by decreasing ACC and ethylene levels in plants.

  12. Drought response of Mucuna pruriens (L.) DC. inoculated with ACC deaminase and IAA producing rhizobacteria.

    Science.gov (United States)

    Saleem, Aansa Rukya; Brunetti, Cecilia; Khalid, Azeem; Della Rocca, Gianni; Raio, Aida; Emiliani, Giovanni; De Carlo, Anna; Mahmood, Tariq; Centritto, Mauro

    2018-01-01

    Drought is one of the major constraints limiting agricultural production worldwide and is expected to increase in the future. Limited water availability causes significant effects to plant growth and physiology. Plants have evolved different traits to mitigate the stress imposed by drought. The presence of plant growth-promoting rhizobacteria (PGPR) could play an important role in improving plant performances and productivity under drought. These beneficial microorganisms colonize the rhizosphere of plants and increase drought tolerance by lowering ethylene formation. In the present study, we demonstrate the potential to improve the growth of velvet bean under water deficit conditions of two different strains of PGPR with ACCd (1-Aminocyclopropane-1-Carboxylate deaminase) activity isolated from rainfed farming system. We compared uninoculated and inoculated plants with PGPR to assess: a) photosynthetic performance and biomass; b) ACC content and ethylene emission from leaves and roots; c) leaf isoprene emission. Our results provided evidence that under drought conditions inoculation with PGPR containing the ACCd enzyme could improve plant growth compared to untreated plants. Ethylene emission from roots and leaves of inoculated velvet bean plants was significantly lower than uninoculated plants. Moreover, isoprene emission increased with drought stress progression and was higher in inoculated plants compared to uninoculated counterparts. These findings clearly illustrate that selected PGPR strains isolated from rainfed areas could be highly effective in promoting plant growth under drought conditions by decreasing ACC and ethylene levels in plants.

  13. Evaluation of culture media for Paenibacillus larvae applied to studies of antimicrobial activity Evaluación de medios de cultivo para el crecimiento de Paenibacillus larvae aplicables en estudios de actividad antimicrobiana

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    L. B. Gende

    2008-09-01

    Full Text Available This study was conducted to compare different liquid culture media for Paenibacillus larvae growth in order to find the best one to be used in studies on activity of antimicrobial substances, such as essential oils. P. larvae presented poor growth in usual broths such as Mueller-Hinton, commonly employed in antimicrobial activity assays. Growth in liquid media was evaluated using Paenibacillus larvae strains isolated from hives located in different geographical zones. The MYT medium (Mueller-Hinton broth, yeast extract and thiamine was selected out of the eight liquid media analyzed, as it proved to be the most adequate due to its higher absorbance at 620 nm. The following mean values were obtained from the four P. larvae strains: 0.227 ± 0.016 for the Cobo strain, 0.279 ± 0.015 for La Plata strain, 0.758 ± 0.020 for Mechongué strain and 0.244 ± 0.0079 for Sierra de los Padres strain, respectively.Este trabajo está orientado a comparar diferentes medios de cultivo líquidos para el crecimiento de Paenibacillus larvae. El objetivo fue encontrar el más apropiado para utilizar en estudios de actividad antimicrobiana de diferentes sustancias, tales como aceites esenciales. P. larvae presenta un crecimiento débil en medios de cultivo como el Mueller-Hinton, comúnmente usado en ensayos de actividad antimicrobiana. Se evaluó el crecimiento en caldos de cultivo de cepas aisladas de colmenas ubicadas en diferentes zonas geográficas. De los ocho medios analizados, el MYT (Mueller-Hinton, extracto de levadura y tiamina mostró ser el más apropiado, en éste se observó el mayor valor de absorbancia a 620 nm. Los valores obtenidos en promedio para los cuatro aislamientos de P. larvae evaluados fueron 0,227 ± 0,016 (cepa de Cobo; 0,279 ± 0,015 (cepa de La Plata; 0,758 ± 0,020 (cepa de Mechongué y 0,244 ± 0,0079 (cepa de Sierra de los Padres.

  14. The effect of plant growth promoting rhizobacteria, nitrogen and phosphorus on relative agronomic efficiency of fertilizers, growth parameters and yield of wheat (Triticum aestivum L. cultivar N-80-19 in Sari

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    Z. Saber

    2016-05-01

    Full Text Available In order to evaluate the efficiency of plant growth promoting rhizobacteria (PGPR plus nitrogen and phosphorous chemical fertilizers on relative agronomic efficiency of P and N fertilizers and some agronomic parameters of wheat (Triticum aestivum L. cultivar N-80-19, an experiment was conducted at Sari Agricultural Sciences and Natural Resources University during growing season of 2008-2009. Experiment was arranged in split-split plot based on randomized complete block design with three levels (0, 25 and 50 kg.ha-1 and sub-plots were considered PGPR at four levels (control, inoculation with nitrogen fixing bacteria (PFB, phosphate solubilizing bacteria (PSB and dual inoculation with PFB and PSB with three replications. Results showed that the application of biofertilizers significantly increased relative agronomic efficiency of N and P fertilizers, spike number, plant height, flag leaf area, grain yield and grain weight of wheat. Application of biofertilizers increased wheat grain yield as much as 46.6% as compared to control. Double inoculation of biofertilizers improved relative agronomic efficiency of fertilizers by 58.4 and 76.5% as compared to control, respectively. Integrated treatments showed higher performance compared to separate treatments. Generally, biofertilizers with low levels of P and N fertilizers significantly improved yield components of wheat without any reduction in yield related parameters.

  15. Promoção de crescimento e controle de tombamento de plântulas de pepino por rizobactérias Growth promotion and damping-off control of cucumber seedling by rhizobacteria

    Directory of Open Access Journals (Sweden)

    Cleusa Maria Mantovanello Lucon

    2008-06-01

    source of nitrogen. Out of ten most effective isolates, five were identified as members of the genus Bacillus, four of Pseudomonas and one of Stenotrophomonas. Out of the 165 tested rhizobacteria isolates, seven have potential to promote cucumber plant growth, and one to control P. aphanidermatum damping-off disease.

  16. Protocols to test the activity of antimicrobial peptides against the honey bee pathogen Paenibacillus larvae.

    Science.gov (United States)

    Khilnani, Jasmin C; Wing, Helen J

    2015-10-01

    Paenibacillus larvae is the causal agent of the honey bee disease American Foulbrood. Two enhanced protocols that allow the activity of antimicrobial peptides to be tested against P. larvae are presented. Proof of principle experiments demonstrate that the honey bee antimicrobial peptide defensin 1 is active in both assays. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Conversion of Squid Pen to Homogentisic Acid via Paenibacillus sp. TKU036 and the Antioxidant and Anti-Inflammatory Activities of Homogentisic Acid

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    San-Lang Wang

    2016-10-01

    Full Text Available The culture supernatant of Paenibacillus sp. TKU036, a bacterium isolated from Taiwanese soils, showed high antioxidant activity (85% when cultured in a squid pen powder (SPP-containing medium at 37 °C for three days. Homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA was isolated and found to be the major antioxidant in the culture supernatant of the SPP-containing medium fermented by Paenibacillus sp. TKU036. Tryptophan was also present in the culture supernatant. The results of high-performance liquid chromatography (HPLC fingerprinting showed that HGA and tryptophan were produced via fermentation but did not pre-exist in the unfermented SPP-containing medium. Neither HGA nor tryptophan was found in the culture supernatants obtained from the fermentation of nutrient broth or other chitinous material, i.e., medium containing shrimp head powder, by Paenibacillus sp. TKU036. The production of HGA via microorganisms has rarely been reported. In this study, we found that squid pen was a potential carbon and nitrogen source for Paenibacillus sp. Tryptophan (105 mg/L and HGA (60 mg/L were recovered from the culture supernatant. The isolated HGA was found to have higher antioxidant activity (IC50 = 6.9 μg/mL than α-tocopherol (IC50 = 17.6 μg/mL. The anti-inflammatory activity of the isolated HGA (IC50 = 10.14 μg/mL was lower than that of quercetin (IC50 = 1.14 μg/mL. As a result, squid pen, a fishery processing byproduct, is a valuable material for the production of tryptophan and the antioxidant and anti-inflammatory HGA via microbial conversion.

  18. Comparative effectiveness of ACC-deaminase and/or nitrogen-fixing rhizobacteria in promotion of maize (Zea mays L.) growth under lead pollution.

    Science.gov (United States)

    Hassan, Waseem; Bano, Rizwana; Bashir, Farhat; David, Julie

    2014-09-01

    Lead (Pb) pollution is appearing as an alarming threat nowadays. Excessive Pb concentrations in agricultural soils result in minimizing the soil fertility and health which affects the plant growth and leads to decrease in crop production. Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria which can protect the plants against many abiotic stresses, and enhance the growth. The study aimed to identify important rhizobacterial strains by using the 1-aminocyclopropane-1-carboxylate (ACC) enrichment technique and examine their inoculation effects in the growth promotion of maize, under Pb pollution. A pot experiment was conducted and six rhizobacterial isolates were used. Pb was added to 2 kg soil in each pot (with 4 seeds/pot) using Pb(NO3)2 at the rate of 0, 100, 200, 300, and 400 mg kg(-1) Pb with three replications in completely randomized design. Rhizobacterial isolates performed significantly better under all Pb levels, i.e., 100 to 400 Pb mg kg(-1) soil, compared to control. Comparing the efficacy of the rhizobacterial isolates under different Pb levels, rhizobacterial isolates having both ACC-deaminase and nitrogen-fixing activities (AN8 and AN12) showed highest increase in terms of the physical, chemical and enzymatic growth parameters of maize, followed by the rhizobacterial isolates having ACC-deaminase activity only (ACC5 and ACC8), and then the nitrogen-fixing rhizobia (Azotobacter and RN5). However, the AN8 isolate showed maximum efficiency, and highest shoot and root length (14.2 and 6.1 cm), seedling fresh and dry weights (1.91 and 0.14 g), chlorophyll a, b, and carotenoids (24.1, 30.2 and 77.7 μg/l), protein (0.82 mg/g), proline (3.42 μmol/g), glutathione S-transferase, peroxidase and catalase (12.3, 4.2 and 7.2 units/mg protein), while the lowest Pb uptake in the shoot and root (0.83 and 0.48 mg/kg) were observed under this rhizobial isolate at the highest Pb level (i.e., 400 Pb mg kg(-1) soil). The results revealed that PGPR

  19. Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola

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    Surender Kumar

    2013-12-01

    Full Text Available An experiment on the metabolite [salicylic acid (SA, jasmonic acid (JA, hydrocyanic acid (HCN and chitinase activity] changes owing to seed treatn1ent with pathogen, plant growth pron1oting rhizobacteria (PGPRs - (P. maltophilia, P. fluorescens and Bacillus subtilis alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola treated seeds showed an initial increase in SA and hydrocyanic acid HCN content and an opposite trend was observed for JA level and chitinase activity. Though, PGPRs inoculation resulted in higher increase in SA level, JA level and chitinase activity in both the cases alone as well as in integration with pathogen, however, maximun1 increase in JA content was explicited in plants raised after seed treatment with P. fluorescens, the most effective rhizobacteria amongst PGPRs studied. Highest increase in HCN content (45 micrograms g-1 over control (24 micrograms g-1 was noticed for P. fluorescens followed by co-seed inoculation with P. fluorescens + pathogen (43 micrograms g-1 at 10 DPL. The co-seed inoculation elicited 68 units at 10 DPI, whereas the pathogen challenged plants showed lower chitinase activity with 42 units. All the metabolites declined slightly or sharply with age of the plant irrespective of inoculations.

  20. Characterisation of a detergent-stable alkaline protease from a novel thermophilic strain Paenibacillus tezpurensis sp. nov. AS-S24-II.

    Science.gov (United States)

    Rai, Sudhir K; Roy, Jetendra K; Mukherjee, Ashis K

    2010-02-01

    An alkaline-protease-producing bacterial strain (AS-S24-II) isolated from a soil sample in Assam is a Gram-stain-positive, catalase-positive, endospore-forming rod and grows at temperatures ranging from 30 degrees C to 60 degrees C and salinity ranging from 0% to 7% (w/v) NaCl. Phenotypic characterisation, chemotaxonomic properties, presence of Paenibacillus-specific signature sequences, and ribotyping data suggested that the strain AS-S24-II represents a novel species of the genus Paenibacillus, for which the name Paenibacillus tezpurensis sp. nov. (MTCC 8959) is proposed. Phylogenetic analysis revealed that P. lentimorbus strain DNG-14 and P. lentimorbus strain DNG-16 represent the closest phylogenetic neighbour of this novel strain. Alkaline protease production (598 x 10(3) U l(-1)) by P. tezpurensis sp. nov. in SmF was optimised by response surface method. A laundry-detergent-stable, Ca(2+)-independent, 43-kDa molecular weight alkaline serine protease from this strain was purified with a 1.7-fold increase in specific activity. The purified protease displayed optimum activity at pH 9.5 and 45-50 degrees C temperature range and exhibited a significant stability and compatibility with surfactants and most of the tested commercial laundry detergents at room temperature. Further, the protease improved the wash performance of detergents, thus demonstrating its feasibility for inclusion in laundry detergent formulations.

  1. Antibiosis plays a role in the context of direct interaction during antagonism of Paenibacillus polymyxa towards Fusarium oxysporum

    NARCIS (Netherlands)

    Dijksterhuis, J; Sanders, M; Gorris, L G; Smid, E J

    Interaction of Fusarium oxysporum and Paenibacillus polymyxa starts with polar attachment of bacteria to the fungal hyphae followed by the formation of a large cluster of non-motile cells embedded in an extracellular matrix in which the bacteria develop endospores. Enumeration of fungal viable

  2. High Milk-Clotting Activity Expressed by the Newly Isolated Paenibacillus spp. Strain BD3526

    Directory of Open Access Journals (Sweden)

    Feng Hang

    2016-01-01

    Full Text Available Paenibacillus spp. BD3526, a bacterium exhibiting a protein hydrolysis circle surrounded with an obvious precipitation zone on skim milk agar, was isolated from raw yak (Bos grunniens milk collected in Tibet, China. Phylogenetic analysis based on 16S rRNA and whole genome sequence comparison indicated the isolate belong to the genus Paenibacillus. The strain BD3526 demonstrated strong ability to produce protease with milk clotting activity (MCA in wheat bran broth. The protease with MCA was predominantly accumulated during the late-exponential phase of growth. The proteolytic activity (PA of the BD3526 protease was 1.33-fold higher than that of the commercial R. miehei coagulant. A maximum MCA (6470 ± 281 SU mL−1 of the strain BD3526 was reached under optimal cultivation conditions. The protease with MCA was precipitated from the cultivated supernatant of wheat bran broth with ammonium sulfate and purified by anion-exchange chromatography. The molecular weight of the protease with MCA was determined as 35 kDa by sodium dodecyl sulfate-polyacrylamide gels electrophoresis (SDS-PAGE and gelatin zymography. The cleavage site of the BD3526 protease with MCA in κ-casein was located at the Met106–Ala107 bond, as determined by mass spectrometry analysis.

  3. Genetic and Biochemical Diversity of Paenibacillus larvae Isolated from Tunisian Infected Honey Bee Broods

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    Chadlia Hamdi

    2013-01-01

    Full Text Available Paenibacillus larvae is the causative agent of American foulbrood (AFB, a virulent disease of honeybee (Apis mellifera larvae. In Tunisia, AFB has been detected in many beekeeping areas, where it causes important economic losses, but nothing is known about the diversity of the causing agent. Seventy-five isolates of P. larvae, identified by biochemical tests and 16S rRNA gene sequencing, were obtained from fifteen contaminated broods showing typical AFB symptoms, collected in different locations in the northern part of the country. Using BOX-PCR, a distinct profile of P. larvae with respect to related Paenibacillus species was detected which may be useful for its identification. Some P. larvae-specific bands represented novel potential molecular markers for the species. BOX-PCR fingerprints indicated a relatively high intraspecific diversity among the isolates not described previously with several molecular polymorphisms identifying six genotypes on polyacrylamide gel. Polymorphisms were also detected in several biochemical characters (indol production, nitrate reduction, and methyl red and oxidase tests. Contrary to the relatively high intraspecies molecular and phenotypic diversity, the in vivo virulence of three selected P. larvae genotypes did not differ significantly, suggesting that the genotypic/phenotypic differences are neutral or related to ecological aspects other than virulence.

  4. Finger Millet Growth and Nutrient Uptake Is Improved in Intercropping With Pigeon Pea Through “Biofertilization” and “Bioirrigation” Mediated by Arbuscular Mycorrhizal Fungi and Plant Growth Promoting Rhizobacteria

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    Krishna Saharan

    2018-06-01

    Full Text Available Legume-cereal intercropping is well known in traditional dry land agriculture. Here, we tested whether finger millet, a shallow-rooted cereal, can profit from neighboring pigeon pea, a deep-rooted legume, in the presence of “biofertilization” with arbuscular mycorrhizal fungi (AMF and plant growth-promoting rhizobacteria (PGPR, under drought conditions. We conducted a greenhouse experiment using compartmented microcosms. Pigeon pea was grown in a deep compartment with access to a moist substrate layer at the bottom, whereas finger millet was grown in a neighboring shallow compartment, separated by 25-μm nylon mesh, without access to the moist substrate layer. In the presence of a common mycorrhizal network (CMN, with or without PGPR, a drought condition had little negative effect on the biomass production of the finger millet plant whereas in absence of biofertilization, finger millet biomass production was less than half compared to well-watered condition. Biofertilization strongly increased nitrogen and phosphorus uptake by both plants, both under well-watered and drought conditions. In the presence of AMF, both plants also acquired 15N and 33P, offered in a labeling compartment accessible to fungal hyphae but not to roots. Our results show that “biofertilization” with AMF alleviates the negative effects of drought condition on finger millet, indicating that the CMN connecting pigeon pea and finger millet exert clearly a positive influence in this simulated intercropping system.

  5. Effect of Plant Growth Promoting Rhizobacteria on the Concentration and Uptake of Macro Nutrients by Corn in a Cd-contaminated Calcareous Soil under Drought Stress

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    shahrzad karami

    2017-02-01

    Full Text Available Introduction: Heavy metals such as cadmium (Cd are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for living organisms. Cadmium competes with many of nutrients to be absorbed by the plant and interferes with their biological roles. Water stress affects the cell structure and the food is diverted from its normal metabolic pathway. It also reduces the availability and uptake of nutrients by the plant. One reason for the reduction of plant growth under drought stress is the accumulation of ethylene in plants. There are ways to mitigate the negative effects of drought stress that one of which is the use of Plant Growth Promoting Rhizobacteria(PGPRs to increasing the availability of nutrients. Soil beneficial bacteria play an important role in the biological cycles and have been used to increase plant health and soil fertility over the past few decades.The aim of this study was to investigate theeffect of PGPRson the concentration and uptake of macro nutrients by corn in a Cd-contaminated calcareous soil under drought stress. Materials and Methods: A greenhouse factorial experiment was conducted in a completely randomized design with three replications. The treatments were two levels of bacteria (with and without bacteria, four levels of Cd (5, 10, 20, and 40 mg kg-1, and three levels of drought stress (without stress, 80, and 65% of field capacity. The pots were filled with 3 kg of treated soil. Cd was treated as its sulfate salt in amounts of 5, 10, 20, and 40 mg kg-1. The soil was mixed uniformly with 150 mg N kg-1 as urea, 20 mg P kg-1 as Ca (H2PO42, 5 mg Fe kg-1 as Fe-EDDHA and 10, 10 and 2.5 mg Zn, Mn and Cu kg-1, respectively as their sulfate salt in order to meet plant needs for these nutrients. Six seeds of Zea mays (var. HIDO were planted at

  6. 2,3-Butanediol and Acetoin Production from Enzymatic Hydrolysate of Ionic Liquid-pretreated Cellulose by Paenibacillus polymyxa

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    Li-qun Jiang

    2015-01-01

    Full Text Available A safe microorganism (class 1, Paenibacillus polymyxa, was used for 2,3-butanediol and acetoin production, which could make the fermentation process cheaper and less complex. It showed a broad substrate spectrum, such as mannose, galactose, cellobiose, glycerol, the mixture of glucose and xylose, and the mixture of glucose and cellobiose. In addition, the strain can utilize highly concentrated glucose that was obtained by enzymatic hydrolysis of ionic liquid-pretreated cellulose. With a 15% initial cellulose consistency, the final glucose concentration was 109.5 g/L with 65.7% glucose yield. Without any treatment, the hydrolysate was successfully used to produce 2,3-butanediol and acetoin with a yield of 81.7% and a productivity of 0.7 g/(L•h by Paenibacillus polymyxa. Higher concentration and higher productivity with relatively high yield, compared with previous works by acid hydrolysis, of 2,3-butanediol and acetoin were achieved. All these novel improvements offer significant opportunities to further decrease the cost of large-scale 2,3-butanediol and acetoin production.

  7. Isolation, identification and characterization of Paenibacillus polymyxa CR1 with potentials for biopesticide, biofertilization, biomass degradation and biofuel production.

    Science.gov (United States)

    Weselowski, Brian; Nathoo, Naeem; Eastman, Alexander William; MacDonald, Jacqueline; Yuan, Ze-Chun

    2016-10-18

    Paenibacillus polymyxa is a plant-growth promoting rhizobacterium that could be exploited as an environmentally friendlier alternative to chemical fertilizers and pesticides. Various strains have been isolated that can benefit agriculture through antimicrobial activity, nitrogen fixation, phosphate solubilization, plant hormone production, or lignocellulose degradation. However, no single strain has yet been identified in which all of these advantageous traits have been confirmed. P. polymyxa CR1 was isolated from degrading corn roots from southern Ontario, Canada. It was shown to possess in vitro antagonistic activities against the common plant pathogens Phytophthora sojae P6497 (oomycete), Rhizoctonia solani 1809 (basidiomycete fungus), Cylindrocarpon destructans 2062 (ascomycete fungus), Pseudomonas syringae DC3000 (bacterium), and Xanthomonas campestris 93-1 (bacterium), as well as Bacillus cereus (bacterium), an agent of food-borne illness. P. polymyxa CR1 enhanced growth of maize, potato, cucumber, Arabidopsis, and tomato plants; utilized atmospheric nitrogen and insoluble phosphorus; produced the phytohormone indole-3-acetic acid (IAA); and degraded and utilized the major components of lignocellulose (lignin, cellulose, and hemicellulose). P. polymyxa CR1 has multiple beneficial traits that are relevant to sustainable agriculture and the bio-economy. This strain could be developed for field application in order to control pathogens, promote plant growth, and degrade crop residues after harvest.

  8. Protein quantity and quality of safflower seed improved by NP fertilizer and rhizobacteria (Azospirillum and Azotobacter spp.

    Directory of Open Access Journals (Sweden)

    Asia eNosheen

    2016-02-01

    Full Text Available Protein is an essential part of human diet. The aim of present study was to improve the protein quality of safflower seed by the application of plant growth promoting rhizobacteria (PGPR in combination with conventional nitrogen and phosphate (NP fertilizers. The seeds of two safflower cultivar Thori and Saif-32, were inoculated with Azospirillum and Azotobacter and grown under field conditions. Protein content and quality was assessed by crude protein, amino acid analysis and SDS-PAGE. Seed crude protein and amino acids (metheonine, phenylanine and glutamic acid showed significant improvement (55%–1250% by Azotobacter supplemented with quarter dose of fertilizers (BTQ at P≤0.05. Additional protein bands were induced in Thori and Saif-32 by BTQ and BTH (Azotobacter supplemented with half dose of fertilizers respectively. The Azospirillum in combination with half dose of fertilizers (SPH and BTQ enhanced the indole acetic acid (90% and gibberellic acid (23%–27% contents in safflower leaf. Taken together, these data suggest that Azospirillum and Azotobacter along with significantly reduced (up to 75% use of NP fertilizers improved the quality and quantity of safflower seed protein.

  9. KB425796-A, a novel antifungal antibiotic produced by Paenibacillus sp. 530603.

    Science.gov (United States)

    Kai, Hirohito; Yamashita, Midori; Takase, Shigehiro; Hashimoto, Michizane; Muramatsu, Hideyuki; Nakamura, Ikuko; Yoshikawa, Koji; Ezaki, Masami; Nitta, Kumiko; Watanabe, Masato; Inamura, Noriaki; Fujie, Akihiko

    2013-08-01

    The novel antifungal macrocyclic lipopeptidolactone, KB425796-A (1), was isolated from the fermentation broth of bacterial strain 530603, which was identified as a new Paenibacillus species based on morphological and physiological characteristics, and 16S rRNA sequences. KB425796-A (1) was isolated as white powder by solvent extraction, HP-20 and ODS-B column chromatography, and lyophilization, and was determined to have the molecular formula C79H115N19O18. KB425796-A (1) showed antifungal activities against Aspergillus fumigatus and the micafungin-resistant infectious fungi Trichosporon asahii, Rhizopus oryzae, Pseudallescheria boydii and Cryptococcus neoformans.

  10. Plant Growth Promoting Rhizobacteria

    Indian Academy of Sciences (India)

    IAS Admin

    known to improve plant growth in many ways when compared to ... roles in agricultural productivity. ... Sustainable agriculture: Sustainable agriculture involves the successful management of agricultural re- ... For the first time Kloepper et al.

  11. Paenibacillus phocaensis sp. nov., isolated from the gut microbiota of a healthy infant

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    M. Tidjani Alou

    2017-03-01

    Full Text Available Paenibacillus phocaensis sp. nov. strain mt24T (= CSUR P2238 = DSM 101777 is a Gram-negative, facultative anaerobic, spore-forming and motile bacilli. This strain was isolated from the stool sample of a healthy infant from Niger. Its genome was estimated to a size of 5 521 415 bp with a 53.54% GC content. It contains 4835 protein-coding genes and 89 RNAs, among which two were 16S rRNA genes. There were also 101 genes (2.09% identified as ORFans.

  12. Genome sequence and description of Paenibacillus ihuae strain GD6 sp. nov., isolated from the stool of a 62-year-old Frenchman

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    C. Al-Bayssari

    2018-05-01

    Full Text Available Paenibacillus ihuae strain GD6 (=CSUR P892 = DSMZ 45751T is the new type strain collected from the stool of a 69-year-old Frenchman admitted to an intensive care unit and receiving a 10-day course of imipenem at the time of stool collection. This is a Gram-positive, facultative anaerobic, rod-shaped bacterium. We describe here the features of this organism, together with its complete genome sequence and annotation. The genome size is 6 719 043 bp with 49.6% G+C content and contains 6211 protein-coding and 65 sRNA genes, including four 5S rRNA genes, one 16S rRNA gene and one 23S rRNA gene. Keywords: Culturomics, Paenibacillus ihuae, taxonogenomics

  13. PLANT-MICROBIAL INTERACTIONS IN THE RHIZOSPHERE – STRATEGIES FOR PLANT GROWTH-PROMOTION

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    Marius Stefan

    2012-03-01

    Full Text Available Plant growth-promoting rhizobacteria (PGPR are a group of bacteria that can actively colonize plant rootsand enhance plant growth using different mechanisms: production of plant growth regulators like indoleacetic acid,gibberellic acid, cytokinins and ethylene(Zahir et al., 2003, providing the host plant with fixed nitrogen, solubilizationof soil phosphorus, enhance Fe uptake, biocontrol, reducing the concentration of heavy metals. PGPR are perfectcandidates to be used as biofertilizers – eco-friendly alternative to common applied chemical fertilizer in today’sagriculture. The most important benefit of PGPR usage is related to the reduction of environmental pollution in conditionof increasing crop yield. This review presents the main mechanisms involved in PGPR promotion of plant growth.

  14. Noncontiguous finished genome sequence and description of Paenibacillus ihumii sp. nov. strain AT5

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    A.H. Togo

    2016-03-01

    Full Text Available Paenibacillus ihumii sp. nov. strain AT5 (= CSUR 1981 = DSM 100664 is the type strain of P. ihumii. This bacterium was isolated from a stool sample from a morbidly obese French patient using the culturomics approach. The genome of this Gram-negative, facultative anaerobic, motile and spore-forming bacillus is 5 924 686 bp long. Genomic analysis identified 253 (5% of 3812 genes as ORFans and at least 2599 (50.03% of 5194 orthologous proteins not shared with the closest phylogenetic species.

  15. Rhamnolipids production by multi-metal-resistant and plant-growth-promoting rhizobacteria.

    Science.gov (United States)

    Singh, Anil Kumar; Cameotra, Swaranjit Singh

    2013-07-01

    The biosurfactant-producing Pseudomonas aeruginosa A11, with plant-growth-promoting (PGP) and multi-metal-resistant (MMR) features was isolated from the rhizosphere of a wild plant Parthenium hysterophorus. The strain A11 was able to utilize glycerol as a carbon source and produce 4,436.9 mg/L of biosurfactant after 120 h of incubation. The biosurfactants was characterized as rhamnolipids (RLs) by thin layer chromatography, Fourier transform infrared spectroscopy, nuclear magnetic resonance, and liquid chromatography-mass spectrometry analysis. Eight different RLs congeners were detected with RhaRhaC₁₀C₁₀ being most abundant. The purified rhamnolipid, dirhamnolipid, and monorhamnolipid reduced the surface tension of water to 29, 36, and 42 mN/m with critical micelle concentration of 83, 125, and 150 mg/L, respectively. The strain A11 demonstrated resistance against all the metals detected in rhizosphere except Hg and Ni. The strain A11 also possessed plant-growth-promoting features like siderophores, hydrogen cyanide, catalase, ammonia production, and phosphate solubilization. The dirhamnolipids formed crystals upon incubation at 4 °C, thus making separation of dirhamnolipids easy. Biosurfactant-producing ability along with MMR and PGP traits of the strain A11 makes it a potential candidate for application in the bacterial assisted enhancement of phytoremediation of heavy-metal-contaminated sites.

  16. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Wintermans, Paul C A; Bakker, Peter A H M; Pieterse, Corné M J

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium.

  17. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Wintermans, P.C.A.; Bakker, P.A.H.M.; Pieterse, C.M.J.

    2016-01-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium.

  18. A novel carboxyl-terminal protease derived from Paenibacillus lautus CHN26 exhibiting high activities at multiple sites of substrates

    DEFF Research Database (Denmark)

    Li, Yunxia; Pan, Yingjie; She, Qunxin

    2013-01-01

    Carboxyl-terminal protease (CtpA) plays essential functions in posttranslational protein processing in prokaryotic and eukaryotic cells. To date, only a few bacterial ctpA genes have been characterized. Here we cloned and characterized a novel CtpA. The encoding gene, ctpAp (ctpA of Paenibacillus...

  19. Surviving bacterial sibling rivalry: inducible and reversible phenotypic switching in Paenibacillus dendritiformis.

    Science.gov (United States)

    Be'er, Avraham; Florin, E-L; Fisher, Carolyn R; Swinney, Harry L; Payne, Shelley M

    2011-01-01

    Natural habitats vary in available nutrients and room for bacteria to grow, but successful colonization can lead to overcrowding and stress. Here we show that competing sibling colonies of Paenibacillus dendritiformis bacteria survive overcrowding by switching between two distinct vegetative phenotypes, motile rods and immotile cocci. Growing colonies of the rod-shaped bacteria produce a toxic protein, Slf, which kills cells of encroaching sibling colonies. However, sublethal concentrations of Slf induce some of the rods to switch to Slf-resistant cocci, which have distinct metabolic and resistance profiles, including resistance to cell wall antibiotics. Unlike dormant spores of P. dendritiformis, the cocci replicate. If cocci encounter conditions that favor rods, they secrete a signaling molecule that induces a switch to rods. Thus, in contrast to persister cells, P. dendritiformis bacteria adapt to changing environmental conditions by inducible and reversible phenotypic switching. In favorable environments, species may face space and nutrient limits due to overcrowding. Bacteria provide an excellent model for analyzing principles underlying overcrowding and regulation of density in nature, since their population dynamics can be easily and accurately assessed under controlled conditions. We describe a newly discovered mechanism for survival of a bacterial population during overcrowding. When competing with sibling colonies, Paenibacillus dendritiformis produces a lethal protein (Slf) that kills cells at the interface of encroaching colonies. Slf also induces a small proportion of the cells to switch from motile, rod-shaped cells to nonmotile, Slf-resistant, vegetative cocci. When crowding is reduced and nutrients are no longer limiting, the bacteria produce a signal that induces cocci to switch back to motile rods, allowing the population to spread. Genes encoding components of this phenotypic switching pathway are widespread among bacterial species, suggesting

  20. Analysis of plant growth-promoting properties of Bacillus amyloliquefaciens UCMB5113 using Arabidopsis thaliana as host plant

    Czech Academy of Sciences Publication Activity Database

    Asari, S.; Tarkowská, Danuše; Rolčík, Jakub; Novák, Ondřej; Palmero, D. V.; Bejai, S.; Meijer, J.

    2017-01-01

    Roč. 245, č. 1 (2017), s. 15-30 ISSN 0032-0935 R&D Projects: GA MŠk LK21306; GA MŠk(CZ) LO1204; GA ČR GA14-34792S Institutional support: RVO:61389030 Keywords : rape brassica-napus * cell elongation * root-growth * rhizobacteria * gibberellins * bacteria * cytokinin * seedlings * defense * stress * Beneficial bacteria * Biocontrol * Growth promotion * Phytohormones * Rhizosphere * Root structure Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 3.361, year: 2016

  1. Decoding the complete arsenal for cellulose and hemicellulose deconstruction in the highly efficient cellulose decomposer Paenibacillus O199

    Czech Academy of Sciences Publication Activity Database

    López-Mondejár, Rubén; Zühlke, D.; Větrovský, Tomáš; Becher, D.; Riedel, K.; Baldrian, Petr

    2016-01-01

    Roč. 9, MAY 14 (2016), s. 104 ISSN 1754-6834 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) EE2.3.30.0003; GA MŠk(CZ) LM2015055; GA MŠk(CZ) LD15086 Institutional support: RVO:61388971 Keywords : Cellulose * Hemicellulose * Paenibacillus Subject RIV: EE - Microbiology, Virology Impact factor: 5.203, year: 2016

  2. Chitosanase production by Paenibacillus ehimensis and its application for chitosan hydrolysis

    Directory of Open Access Journals (Sweden)

    Maria Giovana Binder Pagnoncelli

    2010-12-01

    Full Text Available The chitosanase production by Paenibacillus ehimensis was studied in submerged cultures and the chitosan hydrolysis was evaluated by using these enzymes without purification. The bacterium produced inducibles enzymes after 12 h of growth in a culture medium containing 0.2% (w/v of soluble chitosan as carbon source. The enzyme production was strongly repressed by the presence of glucose. The production started as soon as the available sugars finished in the culture medium. The maximum level of chitosanase activity was 500 U.L-1 at 36°C after 36 h incubation. The crude enzyme was optimally active at pH 6.0 and 55°C and in these conditions, the enzyme presented good stability (6 days. The enzyme without purification was used to hydrolyze the chitosan which resulted chitooligosaccharides between 20 and 30 min of reaction.A produção de quitosanases pelo Paenibacillus ehimensis foi estudada em culturas submersas e a hidrólise da quitosana foi realizada utilizando essas enzimas sem purificação. As enzimas foram obtidas após 12 horas de crescimento desta bactéria em meio de cultivo contendo 0,2% (p/v de quitosana solúvel como fonte de carbono. A produção das enzimas foi fortemente reprimida na presença de glicose, sendo obtida após o consumo total dos açúcares disponibilizados no referido meio de cultivo. A máxima atividade quitosanolítica foi obtida após 36 horas de cultivo a 36ºC, atingindo valores de 500 U.L-1. As enzimas utilizadas no extrato bruto apresentaram melhores atividades quando submetidas a condições de pH e temperatura de 6,0 e 55ºC, respectivamente, e nessas condições permaneceram estáveis durante 6 dias. Essas enzimas sem serem submetidas aos processos de purificação foram utilizadas para hidrolisar a quitosana, obtendo os quito-oligossacarídeos entre 20 e 30 minutos de reação.

  3. Biology of Paenibacillus larvae, a deadly pathogen of honey bee larvae.

    Science.gov (United States)

    Ebeling, Julia; Knispel, Henriette; Hertlein, Gillian; Fünfhaus, Anne; Genersch, Elke

    2016-09-01

    The gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood of honey bees, a notifiable disease in many countries. Hence, P. larvae can be considered as an entomopathogen of considerable relevance in veterinary medicine. P. larvae is a highly specialized pathogen with only one established host, the honey bee larva. No other natural environment supporting germination and proliferation of P. larvae is known. Over the last decade, tremendous progress in the understanding of P. larvae and its interactions with honey bee larvae at a molecular level has been made. In this review, we will present the recent highlights and developments in P. larvae research and discuss the impact of some of the findings in a broader context to demonstrate what we can learn from studying "exotic" pathogens.

  4. Antibacterial properties of grapefruit seed extract against Paenibacillus larvae subsp. larvae.

    Science.gov (United States)

    Semprini, P; Langella, V; Pasini, B; Falda, M T; Calvarese, S

    2004-01-01

    Twenty-one samples of grapefruit seed extract (GSE) either from marketed products or provided by an apiculturist were analysed to verify their inhibition activity, in particular against Paenibacillus larvae subsp. larvae, responsible for American foulbrood. The bactericide capacity of GSE has been measured in Bacillus subtilis BGA, Bacillus cereus 11778, Bacillus cereus K250 and Micrococcus luteus 9341a; these bacteria are normally used in the laboratory to study inhibitors. The results showed that not all GSE have the same inhibitory activity and two of those analysed do not inhibit the five bacteria used. Considering that 19 samples inhibited American foulbrood bacillus, the authors conclude that the use of a natural product (such as GSE) to control this important disease of bees, can be used as a substitute for chemotherapeutic products, after appropriate expedients.

  5. Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective.

    Science.gov (United States)

    Lampis, Silvia; Santi, Chiara; Ciurli, Adriana; Andreolli, Marco; Vallini, Giovanni

    2015-01-01

    A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community.

  6. Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective

    Science.gov (United States)

    Lampis, Silvia; Santi, Chiara; Ciurli, Adriana; Andreolli, Marco; Vallini, Giovanni

    2015-01-01

    A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community. PMID:25741356

  7. Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective.

    Directory of Open Access Journals (Sweden)

    Silvia eLampis

    2015-02-01

    Full Text Available A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: i non-inoculated plants; ii plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A; iii plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4 and Pseudoxanthomonas sp. P4V6 (B, and iv plants inoculated with all five bacterial strains (AB. The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community.

  8. Improved in situ saccharification of cellulose pretreated by dimethyl sulfoxide/ionic liquid using cellulase from a newly isolated Paenibacillus sp. LLZ1.

    Science.gov (United States)

    Hu, Dongxue; Ju, Xin; Li, Liangzhi; Hu, Cuiying; Yan, Lishi; Wu, Tianyun; Fu, Jiaolong; Qin, Ming

    2016-02-01

    A cellulase producing strain was newly isolated from soil samples and identified as Paenibacillus sp. LLZ1. A novel aqueous-dimethyl sulfoxide (DMSO)/1-ethyl-3-methylimidazolium diethyl phosphate ([Emin]DEP)-cellulase system was designed and optimized. In the pretreatment, DMSO was found to be a low-cost substitute of up to 70% ionic liquid to enhance the cellulose dissolution. In the enzymatic saccharification, the optimum pH and temperature of the Paenibacillus sp. LLZ1 cellulase were identified as 6.0 and 40°C, respectively. Under the optimized reaction condition, the conversion of microcrystalline cellulose and bagasse cellulose increased by 39.3% and 37.6%, compared with unpretreated cellulose. Compared to current methods of saccharification, this new approach has several advantages including lower operating temperature, milder pH, and less usage of ionic liquid, indicating a marked progress in environmental friendly hydrolysis of biomass-based materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Draft genome sequence of Paenibacillus algorifonticola sp. nov., an antimicrobial-producing strain

    Directory of Open Access Journals (Sweden)

    Liying Zhu

    2015-09-01

    Full Text Available Paenibacillus algorifonticola sp. nov. is isolated from a cold spring sample from Xinjiang Uyghur Autonomous Region (China, a novel strain that can produce antimicrobial substance against human pathogenic bacteria and fungi, including Staphylococcus aureus and Candida albicans. Here we report a 7.60-Mb assembly of its genome sequence and other useful information, including the coding sequences (CDSs responsible for the biosynthesis of antibacterial factors, anaerobic respiration and several immune-associated reactions. Also, prospective studies on P. algorifonticola sp. nov. in the cold spring might offer a potential source for the discovery of bioactive compounds with medical value. The data repository is deposited on the website http://www.ncbi.nlm.nih.gov/nuccore/LAQO00000000 and the accession number is LAQO00000000.

  10. Effect of Plant Growth Promoting Rhizobacteria on Yield and Yield Components of Garlic Medicinal Plant (Allium sativum L. under the Conditions of Different Organic and Chemical Fertilizers Application

    Directory of Open Access Journals (Sweden)

    Yaser Esmaeilian

    2018-03-01

    often underestimated. Garlic is easy to grow and can be grown year-round in mild climates. Garlic cloves are used for consumption (raw and cooked or for medicinal purposes. They have a pungent characteristic, spicy flavor that mellows and sweetens considerably with cooking. Materials and Methods: In order to evaluate the effect of biofertilizers and organic and chemical fertilizers on yield and yield components of garlic (Allium sativum L., a split plot experiment based on RCBD with three replications was conducted in 2015-2016 growing seasons, in Gonabad University, Iran. Main plot included different organic and chemical fertilizers (1- vermicompost, 2- cow manure, 3- chemical fertilizer and 4- control and sub plot included plant growth promoting rhizobacteria (nitroxin, biophosphorous and control. In order to determine physic-chemical properties of soil, sampling was performed at the depth of 0 to 30 cm. Before cultivation, 7 and 30 t.ha-1 vermicompost and cow manure were added to the soil, respectively. Nutrient requirement of garlic for nitrogen, phosphorous and potassium from the chemical source was considered 40, 50 and 60 kg.ha-1. For application of biofertilizers, bulblets inoculated with plant growth promoting rhizobacteria for 15 minutes. Distance in and between rows was considered 10 and 20 cm, respectively. Weeds were controlled manually three times. At the end of the growing season, economic yield, biological yield, plant height, shoot dry weight, bulb diameter, bulblet weight per plant, bulblet volume per plant and bulblet number per plant were measured. Analysis of data variance was performed by using SAS software (Ver 9.1. Results and Discussion: The results showed that simple effect of chemical fertilizer on bulb diameter was not significant but combined application of chemical fertilizer and biophosphorous increased bulb diameter as much as 18% compared to control. Combined application of nitroxin and cow manure increased bulblet weight per plant by 41

  11. Antibiofilm Activity, Compound Characterization, and Acute Toxicity of Extract from a Novel Bacterial Species of Paenibacillus

    Directory of Open Access Journals (Sweden)

    Saad Musbah Alasil

    2014-01-01

    Full Text Available The effectiveness of many antimicrobial agents is currently decreasing; therefore, it is important to search for alternative therapeutics. Our study was carried out to assess the in vitro antibiofilm activity using microtiter plate assay, to characterize the bioactive compounds using Ultra Performance Liquid Chromatography-Diode Array Detection and Liquid Chromatography-Mass Spectrometry and to test the oral acute toxicity on Sprague Dawley rats of extract derived from a novel bacterial species of Paenibacillus strain 139SI. Our results indicate that the crude extract and its three identified compounds exhibit strong antibiofilm activity against a broad range of clinically important pathogens. Three potential compounds were identified including an amino acid antibiotic C8H20N3O4P (MW 253.237, phospholipase A2 inhibitor C21H36O5 (MW 368.512, and an antibacterial agent C14H11N3O2 (MW 253.260. The acute toxicity test indicates that the mortality rate among all rats was low and that the biochemical parameters, hematological profile, and histopathology examination of liver and kidneys showed no significant differences between experimental groups P>0.05. Overall, our findings suggest that the extract and its purified compounds derived from novel Paenibacillus sp. are nontoxic exhibiting strong antibiofilm activity against Gram-positive and Gram-negative pathogens that can be useful towards new therapeutic management of biofilm-associated infections.

  12. Differential response of potato toward inoculation with taxonomically diverse plant growth promoting Rhizobacteria

    NARCIS (Netherlands)

    Naqqash, Tahir; Hameed, Sohail; Imran, Asma; Hanif, Muhammad Kashif; Majeed, Afshan; van Elsas, Jan Dirk

    2016-01-01

    Rhizosphere engineering with beneficial plant growth promoting bacteria offers great promise for sustainable crop yield. Potato is an important food commodity that needs large inputs of nitrogen and phosphorus fertilizers. To overcome high fertilizer demand (especially nitrogen), five bacteria,

  13. The Effect of Plant Growth Promoting Rhizobacteria (PGPR and Phosphate Solubilizing Microorganism (PSM on Yield and Yield Components of Wheat (cv. N80 under Different Nitrogen and Phosphorous Fertilizers Levels in Greenhouse Condition

    Directory of Open Access Journals (Sweden)

    S. H Bahari saravi

    2013-04-01

    Full Text Available In order to evaluate the effect of plant growth promoting rhizobacteria (PGPR and phosphate solubilizing microorganism (PSM on yield and yield components of wheat a pot experiment was conducted at Sari Agricultural Sciences and Natural Resources University during 2009. Experiment was arranged in factorial based on completely randomized design in three replicates. Treatments were included bio-fertilizer in four levels (non-inoculation control, Phosphate Barvare 2 (Pseudomonas fluorescens+Bacillus subtilis, Supernitroplus (Azotobacter brasilense+Azospirillum lipoferum and Nitroxine (Azospirillum + Pseudomona + Bacillus, three levels of chemical nitrogen fertilizer (0, 75 and 150 kg urea/ha and three levels of phosphorus fertilizer (0, 60 and 120 kg super phosphate triple/ha. Results showed that the studied treatments (biofertilizer, nitrogen and phosphate inorganic fertilizers had significant effect on grain number per spike, 1000 grain weight, grain yield, straw yield, biological yield and harvest index. Interaction effect between biofertilizer and chemical fertilizers was significant in terms of grain yield. The maximum grain yield was resulted from simultaneously applying of Nitroxine and 75 kg ha-1 nitrogen fertilizer. By contrast, the highest straw yield was obtained when 150 kg nitrogen fertilizer was used. Grain yield had the maximum correlation with biological yield (r=0.85**. Grain yield positively and significantly correlated with grain number per spike (r=0.73**, 1000 grain weight (r=0.68**, straw yield (r=0.56** and harvest index (r=0.69**. In conclusion biofertilizer inoculations could reduce application of nitrogen and phosphorus chemical fertilizers and increase plant performance.

  14. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City.

    Science.gov (United States)

    Peréz de la Rosa, D; Pérez de la Rosa, J J; Cossio-Bayugar, R; Miranda-Miranda, E; Lozano, L; Bravo-Díaz, M A; Rocha-Martínez, M K; Sachman-Ruiz, B

    2015-08-27

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). Copyright © 2015 Peréz de la Rosa et al.

  15. Rhizonin A from Burkholderia sp. KCTC11096 and Its Growth Promoting Role in Lettuce Seed Germination

    Directory of Open Access Journals (Sweden)

    Sang-Mo Kang

    2012-07-01

    Full Text Available We isolated and identified a gibberellin-producing Burkholderia sp. KCTC 11096 from agricultural field soils. The culture filtrate of plant growth promoting rhizobacteria (PGPR significantly increased the germination and growth of lettuce and Chinese cabbage seeds. The ethyl acetate extract of the PGPR culture showed significantly higher rate of lettuce seed germination and growth as compared to the distilled water treated control. The ethyl acetate fraction of the Burkholderia sp. was subjected to bioassay-guided isolation and we obtained for the first time from a Burkholderia sp. the plant growth promoting compound rhizonin A (1, which was characterized through NMR and MS techniques. Application of various concentrations of 1 significantly promoted the lettuce seed germination as compared to control.

  16. Deep Sequencing-Identified Kanamycin-Resistant Paenibacillus sp. Strain KS1 Isolated from Epiphyte Tillandsia usneoides (Spanish Moss) in Central Florida, USA.

    Science.gov (United States)

    Lata, Pushpa; Govindarajan, Subramaniam S; Qi, Feng; Li, Jian-Liang; Sahoo, Malaya K

    2017-02-02

    Paenibacillus sp. strain KS1 was isolated from an epiphyte, Tillandsia usneoides (Spanish moss), in central Florida, USA. Here, we report a draft genome sequence of this strain, which consists of a total of 398 contigs spanning 6,508,195 bp, with a G+C content of 46.5% and comprising 5,401 predicted coding sequences. Copyright © 2017 Lata et al.

  17. Draft Genome Sequence of Paenibacillus sp. Strain DMB20, Isolated from Alang Ship-Breaking Yard, Which Harbors Genes for Xenobiotic Degradation.

    Science.gov (United States)

    Shah, Binal; Jain, Kunal; Patel, Namrata; Pandit, Ramesh; Patel, Anand; Joshi, Chaitanya G; Madamwar, Datta

    2015-06-11

    Paenibacillus sp. strain DMB20, in cometabolism with other Proteobacteria and Firmicutes, exhibits azoreduction of textile dyes. Here, we report the draft genome sequence of this bacterium, consisting of 6,647,181 bp with 7,668 coding sequences (CDSs). The data presented highlight multiple sets of functional genes associated with xenobiotic compound degradation. Copyright © 2015 Shah et al.

  18. Removal of Cadmium from aqueous solution by polysaccharide produced from Paenibacillus polymyxa

    Energy Technology Data Exchange (ETDEWEB)

    Mokaddem, H., E-mail: hmokadz@yahoo.fr [Laboratoire de Genie de la Reaction, Faculte de Genie Mecanique et Genie des Procedes, Universite des Sciences et de la Technologie Houari Boumediene (USTHB), BP32 El Alia, Bab Ezzouar 16111, Alger (Algeria); Sadaoui, Z. [Laboratoire de Genie de la Reaction, Faculte de Genie Mecanique et Genie des Procedes, Universite des Sciences et de la Technologie Houari Boumediene (USTHB), BP32 El Alia, Bab Ezzouar 16111, Alger (Algeria); Boukhelata, N. [Laboratoire de Biologie et Physiologie des Organismes, Faculte des Sciences Biologiques, Universite des Sciences et de la Technologie Houari Bomediene (USTHB), BP32 El Alia Bab Ezzouar 16111, Alger (Algeria); Azouaou, N. [Laboratoire de Genie de la Reaction, Faculte de Genie Mecanique et Genie des Procedes, Universite des Sciences et de la Technologie Houari Boumediene (USTHB), BP32 El Alia, Bab Ezzouar 16111, Alger (Algeria); Kaci, Y. [Laboratoire de Biologie et Physiologie des Organismes, Faculte des Sciences Biologiques, Universite des Sciences et de la Technologie Houari Bomediene (USTHB), BP32 El Alia Bab Ezzouar 16111, Alger (Algeria)

    2009-12-30

    This paper deals with the removal of Cadmium from aqueous solutions by polysaccharide produced from Paenibacillus polymyxa. The effects of contact time, initial metal ions concentration, mass of the polysaccharide and pH were studied. The Freundlich and Dubinin-Radushkevich (D-R) models have been applied and the equilibrium adsorption was found to best fit the Dubinin-Radushkevich adsorption isotherm based on the coefficient of correlation, R{sup 2}. The maximum Cd{sup 2+} uptake was 520.09 mg g{sup -1}. An empirical modeling was performed by using a 2{sup 3} full factorial design and a regression equation for adsorption of Cd{sup 2+} was determined from the data. The pH and the initial concentration of Cadmium are the most significant parameters affecting Cd{sup 2+} adsorption followed by the mass of the polysaccharide.

  19. Quantitative 16S rDNA-targeted polymerase chain reaction and oligonucleotide hybridization for the detection of Paenibacillus azotofixans in soil and the wheat rhizosphere

    NARCIS (Netherlands)

    Rosado, A.S.; Seldin, L.; Wolters, A.; Elsas, van J.D.

    1996-01-01

    A molecular method for the detection of Paenibacillus azotofixans in soil and the wheat rhizosphere was developed. The system consisted of polymerase chain reaction (PCR) amplification of part of the variable V1 to V4 regions of the 16S ribosomal RNA gene, followed by hybridization with a specific

  20. Paenibacillus polymyxa PKB1 produces variants of polymyxin B-type antibiotics.

    Science.gov (United States)

    Shaheen, Mohamed; Li, Jingru; Ross, Avena C; Vederas, John C; Jensen, Susan E

    2011-12-23

    Polymyxins are cationic lipopeptide antibiotics active against many species of Gram-negative bacteria. We sequenced the gene cluster for polymyxin biosynthesis from Paenibacillus polymyxa PKB1. The 40.8 kb gene cluster comprises three nonribosomal peptide synthetase-encoding genes and two ABC transporter-like genes. Disruption of a peptide synthetase gene abolished all antibiotic production, whereas deletion of one or both transporter genes only reduced antibiotic production. Computational analysis of the peptide synthetase modules suggested that the enzyme system produces variant forms of polymyxin B (1 and 2), with D-2,4-diaminobutyrate instead of L-2,4-diaminobutyrate in amino acid position 3. Two antibacterial metabolites were resolved by HPLC and identified by high-resolution mass spectrometry and MS/MS sequencing as the expected variants 3 and 4 of polymyxin B(1) (1) and B(2) (2). Stereochemical analysis confirmed the presence of both D-2,4-diaminobutyrate and L-2,4-diaminobutyrate residues. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Inhibición de Paenibacillus larvae empleando una mezcla de aceites esenciales y timol Inhibition of Paenibacillus larvae employing a mixture of essential oils and thymol

    Directory of Open Access Journals (Sweden)

    S. R. Fuselli

    2006-04-01

    Full Text Available Se evaluó la actividad antimicrobiana in vitro de una mezcla de dos aceites esenciales y timol frente a Paenibacillus larvae, agente causal de la enfermedad Loque americana, que afecta a las abejas. Los aceites esenciales utilizados fueron canela (Cinnamomum zeylanicum y tomillo (Thymus vulgaris, con el agregado de timol, componente mayoritario del tomillo presente en un 39,9%. Los parámetros medidos fueron la concentración inhibitoria mínima (CIM en caldo Muller-Hinton, mediante dilución seriada, y la concentración bactericida mínima (CBM en agar MYPGP. El aceite esencial de tomillo registró valores de CIM entre 150 y 250 μg/ml, y de CBM entre 200 y 300 μg/ml, mientras que para el aceite esencial de canela los valores de CIM y de CBM obtenidos fueron 50 a 100 μg/ml y 100 a 125 μg/ml, respectivamente. El timol presentó valores de CIM y de CBM similares, de 100 a 150 μg/ml. No se detectaron diferencias significativas entre las cepas bacterianas estudiadas, pero sí entre la actividad de los aceites esenciales y la del timol (PIn vitro antimicrobial activity of a mixture of two essential oils and thymol against Paenibacillus larvae, causal agent of American Foulbrood (AFB, was evaluated. The essential oils were extracted from cinnamon (Cinnamomum zeylanicum and thyme (Thymus vulgaris. The third component used, thymol, is the major component of the essential oil of thyme which contains 39.9 % of thymol. Minimal inhibitory concentration (MIC in Mueller-Hinton broth by the tube dilution method and minimal bactericide concentration (MBC on MYPGP agar were evaluated. Thyme registered MIC values of 150-250 μg/ml and MBC values of 200-300 μg/ml, while the MIC and MBC values obtained for cinnamon were of 50-100 μg/ml and 100-125 μg/ml. Thymol showed similar MIC and MBC values of 100-150 μg/ml. No significant differences between the bacterial strains were detected, but significant differences between essential oils and thymol activity

  2. Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions.

    Science.gov (United States)

    Huang, X-F; Zhou, D; Guo, J; Manter, D K; Reardon, K F; Vivanco, J M

    2015-03-01

    The aim of this study was to evaluate effects of PGPR (plant growth-promoting rhizobacteria) isolated from rainforest soil on different plants under limited nitrogen conditions. Bacterial isolates from a Peruvian rainforest soil were screened for plant growth-promoting effects on Arabidopsis (Col-0). Four selected isolates including one Bacillus subtilis, two B. atrophaeus and one B. pumilus significantly promoted growth of Zea mays L. and Solanum lycopersicum under greenhouse conditions. Moreover, the PGPRs significantly promoted growth of S. lycopersicum in both low and nitrogen-amended soil conditions. These PGPR strains were further studied to obtain insights into possible mechanisms of plant growth promotion. Volatile chemicals from those isolates promoted Arabidopsis growth, and the expression of genes related to IAA production was induced in the Arabidopsis plants treated with PGPRs. Further, selected PGPR strains triggered induced systemic resistance (ISR) against Pseudomonas syringae pv tomato DC3000 in Arabidopsis. PGPR strains isolated from the rainforest soil promoted the plant growth of Arabidopsis, corn and tomato. New PGPR that have wider adaptability to different crops, soils and environmental conditions are needed to decrease our reliance on agricultural amendments derived from fossil-based fuels. The PGPRs isolated from a nonagricultural site constitute new plant growth-promoting strains that could be developed for agricultural uses. © 2014 The Society for Applied Microbiology.

  3. Understanding the molecular basis of plant growth promotional effect of Pseudomonas fluorescens on rice through protein profiling.

    Science.gov (United States)

    Kandasamy, Saveetha; Loganathan, Karthiba; Muthuraj, Raveendran; Duraisamy, Saravanakumar; Seetharaman, Suresh; Thiruvengadam, Raguchander; Ponnusamy, Balasubramanian; Ramasamy, Samiyappan

    2009-12-24

    Plant Growth Promoting Rhizobacteria (PGPR), Pseudomonas fluorescens strain KH-1 was found to exhibit plant growth promotional activity in rice under both in-vitro and in-vivo conditions. But the mechanism underlying such promotional activity of P. fluorescens is not yet understood clearly. In this study, efforts were made to elucidate the molecular responses of rice plants to P. fluorescens treatment through protein profiling. Two-dimensional polyacrylamide gel electrophoresis strategy was adopted to identify the PGPR responsive proteins and the differentially expressed proteins were analyzed by mass spectrometry. Priming of P. fluorescens, 23 different proteins found to be differentially expressed in rice leaf sheaths and MS analysis revealed the differential expression of some important proteins namely putative p23 co-chaperone, Thioredoxin h- rice, Ribulose-bisphosphate carboxylase large chain precursor, Nucleotide diPhosphate kinase, Proteosome sub unit protein and putative glutathione S-transferase protein. Functional analyses of the differential proteins were reported to be directly or indirectly involved in growth promotion in plants. Thus, this study confirms the primary role of PGPR strain KH-1 in rice plant growth promotion.

  4. Identification and functional analysis of gene cluster involvement in biosynthesis of the cyclic lipopeptide antibiotic pelgipeptin produced by Paenibacillus elgii

    Directory of Open Access Journals (Sweden)

    Qian Chao-Dong

    2012-09-01

    Full Text Available Abstract Background Pelgipeptin, a potent antibacterial and antifungal agent, is a non-ribosomally synthesised lipopeptide antibiotic. This compound consists of a β-hydroxy fatty acid and nine amino acids. To date, there is no information about its biosynthetic pathway. Results A potential pelgipeptin synthetase gene cluster (plp was identified from Paenibacillus elgii B69 through genome analysis. The gene cluster spans 40.8 kb with eight open reading frames. Among the genes in this cluster, three large genes, plpD, plpE, and plpF, were shown to encode non-ribosomal peptide synthetases (NRPSs, with one, seven, and one module(s, respectively. Bioinformatic analysis of the substrate specificity of all nine adenylation domains indicated that the sequence of the NRPS modules is well collinear with the order of amino acids in pelgipeptin. Additional biochemical analysis of four recombinant adenylation domains (PlpD A1, PlpE A1, PlpE A3, and PlpF A1 provided further evidence that the plp gene cluster involved in pelgipeptin biosynthesis. Conclusions In this study, a gene cluster (plp responsible for the biosynthesis of pelgipeptin was identified from the genome sequence of Paenibacillus elgii B69. The identification of the plp gene cluster provides an opportunity to develop novel lipopeptide antibiotics by genetic engineering.

  5. Draft Genome Sequence of a Cellulase-Producing Psychrotrophic Paenibacillus Strain, IHB B 3415, Isolated from the Cold Environment of the Western Himalayas, India.

    Science.gov (United States)

    Dhar, Hena; Swarnkar, Mohit Kumar; Gulati, Arvind; Singh, Anil Kumar; Kasana, Ramesh Chand

    2015-02-19

    Paenibacillus sp. strain IHB B 3415 is a cellulase-producing psychrotrophic bacterium isolated from a soil sample from the cold deserts of Himachal Pradesh, India. Here, we report an 8.44-Mb assembly of its genome sequence with a G+C content of 50.77%. The data presented here will provide insights into the mechanisms of cellulose degradation at low temperature. Copyright © 2015 Dhar et al.

  6. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays

    International Nuclear Information System (INIS)

    De Guzman, Zenaida M.; Cervancia, Cleofas R.; Dimasuay, Kris Genelyn B.; Tolentino, Mitos M.; Abrera, Gina B.; Cobar, Ma. Lucia C.; Fajardo, Alejandro C.; Sabino, Noel G.; Manila-Fajardo, Analinda C.; Feliciano, Chitho P.

    2011-01-01

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a 60 Co source. Surviving spores were counted and used to estimate the decimal reduction (D 10 ) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10 5 -9x10 3 spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D min ) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to γ-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials. - Highlights: → We characterized Paenibacillus larvae and determined its radiation sensitivity. → We investigated the effectiveness of gamma rays in inactivating P. larvae. → Gamma radiation inactivates P. larvae. → 15 kGy is effective for the sterilization of P. larvae-infected hives. → Irradiation produces no visible changes in the hives' body, waxes and frames.

  7. Lipopeptide biosurfactants from Paenibacillus polymyxa inhibit single and mixed species biofilms.

    Science.gov (United States)

    Quinn, Gerry A; Maloy, Aaron P; McClean, Stephen; Carney, Brian; Slater, John W

    2012-01-01

    Although biofilms are recognised as important in microbial colonisation, solutions to their inhibition are predominantly based on planktonic assays. These solutions have limited efficacy against biofilms. Here, a series of biofilm-orientated tests were used to identify anti-biofilm compounds from marine micro-flora. This led to the isolation of a complex of anti-biofilm compounds from an extract of Paenibacillus polymyxa (PPE). A combination of rpHPLC and mass spectrometry identified the principle components of PPE as fusaricidin B (LI-FO4b) and polymyxin D1, with minor contributions from surfactins. This complex (PPE) reduced the biofilm biomass of Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus bovis. In contrast, ampicillin was only effective against S. aureus. PPE also inhibited a self-assembling marine biofilm (SAMB) in co-incubation assays by 99.3% ± 1.9 and disrupted established SAMB by 72.4% ± 4.4, while ampicillin showed no significant reduction. The effectiveness of this complex of lipopeptides against single and multispecies biofilms suggests a future role in biofilm prevention strategies.

  8. Production of xylooligosaccharides from forest waste by membrane separation and Paenibacillus xylanase hydrolysis

    Directory of Open Access Journals (Sweden)

    Chun-Han Ko

    2013-02-01

    Full Text Available Xylooligosaccharides (XO, derived from the alkaline (NaOH extractant of Mikania micrantha, were produced using multiple staged membrane separation and enzymatic xylanolysis. Staged nanofiltration (NMX, ultrafiltration (EUMX, and centrifugation (EMX processes for the ethanol precipitates were conducted. NMX recovered 97.26% of total xylose and removed 73.18% of sodium ions. Concentrations of total xylose were raised from 10.98 to 51.85 mg/mL by the NMX process. Recovered xylan-containing solids were hydrolyzed by the recombinant Paenibacillus xylanase. 68% XO conversions from total xylose of NMX was achieved in 24 hours. Xylopentaose (DP 5 was the major product from NMX and EMX hydrolysis. Xylohexaose (DP 6 was the major product from EUMX hydrolysis. Results of the present study suggest the applicability for XO production by nanofiltration, as NMX gave higher XO yields compared to those from a conventional ethanol-related lignocellulosic waste conversion process.

  9. The genome of Paenibacillus sabinae T27 provides insight into evolution, organization and functional elucidation of nif and nif-like genes.

    Science.gov (United States)

    Li, Xinxin; Deng, Zhiping; Liu, Zhanzhi; Yan, Yongliang; Wang, Tianshu; Xie, Jianbo; Lin, Min; Cheng, Qi; Chen, Sanfeng

    2014-08-27

    Most biological nitrogen fixation is catalyzed by the molybdenum nitrogenase. This enzyme is a complex which contains the MoFe protein encoded by nifDK and the Fe protein encoded by nifH. In addition to nifHDK, nifHDK-like genes were found in some Archaea and Firmicutes, but their function is unclear. We sequenced the genome of Paenibacillus sabinae T27. A total of 4,793 open reading frames were predicted from its 5.27 Mb genome. The genome of P. sabinae T27 contains fifteen nitrogen fixation (nif) genes, including three nifH, one nifD, one nifK, four nifB, two nifE, two nifN, one nifX and one nifV. Of the 15 nif genes, eight nif genes (nifB, nifH, nifD, nifK, nifE, nifN, nifX and nifV) and two non-nif genes (orf1 and hesA) form a complete nif gene cluster. In addition to the nif genes, there are nitrogenase-like genes, including two nifH-like genes and five pairs of nifDK-like genes. IS elements on the flanking regions of nif and nif-like genes imply that these genes might have been obtained by horizontal gene transfer. Phylogenies of the concatenated 8 nif gene (nifB, nifH, nifD, nifK, nifE, nifN, nifX and nifV) products suggest that P. sabinae T27 is closely related to Frankia. RT-PCR analysis showed that the complete nif gene cluster is organized as an operon. We demonstrated that the complete nif gene cluster under the control of σ70-dependent promoter enabled Escherichia coli JM109 to fix nitrogen. Also, here for the first time we demonstrated that unlike nif genes, the transcriptions of nifHDK-like genes were not regulated by ammonium and oxygen, and nifH-like or nifD-like gene could not restore the nitrogenase activity of Klebsiella pneumonia nifH- and nifD- mutant strains, respectively, suggesting that nifHDK-like genes were not involved in nitrogen fixation. Our data and analysis reveal the contents and distribution of nif and nif-like genes and contribute to the study of evolutionary history of nitrogen fixation in Paenibacillus. For the first time we

  10. Lettuce and rhizosphere microbiome responses to growth promoting Pseudomonas species under field conditions.

    Science.gov (United States)

    Cipriano, Matheus A P; Lupatini, Manoeli; Lopes-Santos, Lucilene; da Silva, Márcio J; Roesch, Luiz F W; Destéfano, Suzete A L; Freitas, Sueli S; Kuramae, Eiko E

    2016-12-01

    Plant growth promoting rhizobacteria are well described and recommended for several crops worldwide. However, one of the most common problems in research into them is the difficulty in obtaining reproducible results. Furthermore, few studies have evaluated plant growth promotion and soil microbial community composition resulting from bacterial inoculation under field conditions. Here we evaluated the effect of 54 Pseudomonas strains on lettuce (Lactuca sativa) growth. The 12 most promising strains were phylogenetically and physiologically characterized for plant growth-promoting traits, including phosphate solubilization, hormone production and antagonism to pathogen compounds, and their effect on plant growth under farm field conditions. Additionally, the impact of beneficial strains on the rhizospheric bacterial community was evaluated for inoculated plants. The strains IAC-RBcr4 and IAC-RBru1, with different plant growth promoting traits, improved lettuce plant biomass yields up to 30%. These two strains also impacted rhizosphere bacterial groups including Isosphaera and Pirellula (phylum Planctomycetes) and Acidothermus, Pseudolabrys and Singusphaera (phylum Actinobacteria). This is the first study to demonstrate consistent results for the effects of Pseudomonas strains on lettuce growth promotion for seedlings and plants grown under tropical field conditions. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Multilocus sequence typing, biochemical and antibiotic resistance characterizations reveal diversity of North American strains of the honey bee pathogen Paenibacillus larvae.

    Science.gov (United States)

    Krongdang, Sasiprapa; Evans, Jay D; Pettis, Jeffery S; Chantawannakul, Panuwan

    2017-01-01

    Paenibacillus larvae is a Gram positive bacterium and the causative agent of the most widespread fatal brood disease of honey bees, American foulbrood (AFB). A total of thirty-three independent Paenibacillus larvae isolates from various geographical origins in North America and five reference strains were investigated for genetic diversity using multilocus sequence typing (MLST). This technique is regarded to be a powerful tool for epidemiological studies of pathogenic bacteria and is widely used in genotyping assays. For MLST, seven housekeeping gene loci, ilvD (dihydroxy-acid dyhydrogenase), tri (triosephosphate isomerase), purH (phospharibosyl-aminoimidazolecarboxamide), recF (DNA replication and repair protein), pyrE (orotate phosphoribosyltransferase), sucC (succinyl coenzyme A synthetase β subunit) and glpF (glycerol uptake facilitator protein) were studied and applied for primer designs. Previously, ERIC type DNA fingerprinting was applied to these same isolates and the data showed that almost all represented the ERIC I type, whereas using BOX-PCR gave an indication of more diversity. All isolates were screened for resistance to four antibiotics used by U.S. beekeepers, showing extensive resistance to tetracycline and the first records of resistance to tylosin and lincomycin. Our data highlight the intraspecies relationships of P. larvae and the potential application of MLST methods in enhancing our understanding of epidemiological relationships among bacterial isolates of different origins.

  12. Multilocus sequence typing, biochemical and antibiotic resistance characterizations reveal diversity of North American strains of the honey bee pathogen Paenibacillus larvae.

    Directory of Open Access Journals (Sweden)

    Sasiprapa Krongdang

    Full Text Available Paenibacillus larvae is a Gram positive bacterium and the causative agent of the most widespread fatal brood disease of honey bees, American foulbrood (AFB. A total of thirty-three independent Paenibacillus larvae isolates from various geographical origins in North America and five reference strains were investigated for genetic diversity using multilocus sequence typing (MLST. This technique is regarded to be a powerful tool for epidemiological studies of pathogenic bacteria and is widely used in genotyping assays. For MLST, seven housekeeping gene loci, ilvD (dihydroxy-acid dyhydrogenase, tri (triosephosphate isomerase, purH (phospharibosyl-aminoimidazolecarboxamide, recF (DNA replication and repair protein, pyrE (orotate phosphoribosyltransferase, sucC (succinyl coenzyme A synthetase β subunit and glpF (glycerol uptake facilitator protein were studied and applied for primer designs. Previously, ERIC type DNA fingerprinting was applied to these same isolates and the data showed that almost all represented the ERIC I type, whereas using BOX-PCR gave an indication of more diversity. All isolates were screened for resistance to four antibiotics used by U.S. beekeepers, showing extensive resistance to tetracycline and the first records of resistance to tylosin and lincomycin. Our data highlight the intraspecies relationships of P. larvae and the potential application of MLST methods in enhancing our understanding of epidemiological relationships among bacterial isolates of different origins.

  13. Effect of plant growth promoting rhizobia on seed germination and seedling traits in Acacia senegal

    Directory of Open Access Journals (Sweden)

    S.K. Singh

    2011-11-01

    Full Text Available Among arid zone tree species, Acacia senegal and Prosopis cineraria are the most important dryland resources of Western Rajasthan desert ecosystem. Due to ecological, biological and molecular similarities, they are often studied together. The climatic conditions in this region restrict the build-up of soil organic matter and soils are generally deficient in nitrogen. Studies were carried out to isolate and molecularly characterize the diverse group of plant growth promoting rhizobacteria from root nodules of native A. senegal and P. cineraria and their effect on seed germination and seedling traits in two genotypes of A. senegal. The direct sequencing of 16S rDNA region resulted in molecular identification of plant growth promoting rhizobacteria as Bacillus licheniformis, Sinorhizobium saheli isolated from root nodules of A. senegal and S. kostiense and S. saheli isolated from root nodules of P. cineraria. The partial sequences of 16S rDNA were assigned Gen accession numbers HQ738496, HQ738499, HQ738506 and HQ738508. Scarification treatment with sulphuric acid (98% for 15 minutes was able to break the exogenous seed dormancy and enhanced germination percentage in control treatment to 90% and 92.5% in A. senegal in genotypes CAZRI 113AS and CAZRI 35AS, respectively. The treatments with Bacillus licheniformis or S. kostiense, either inoculated individually or as coinoculants, had positive effect on phenotypic traits of germination. Two A. senegal genotypes exhibited significant differences with regard to all the phenotypic traits. On the other hand, treatments with S. saheli isolated from either A. senegal or P. cineraria had negative effects on germination and related phenotypic traits. Values of the coeffivient of determination (R2 over 80% for root length versus shoot length, root/shoot ratio and seedling weight respectively validate that the observed attributes are inter-dependable and linear progression trend can be predicted.

  14. TEKNIK PENGATURAN AIR PADA INTENSIFIKASI PADI AEROB TERKENDALI-BERBASIS ORGANIK (IPAT-BO UNTUK MENINGKATKAN POPULASI RHIZOBACTERIA, EFISIENSI PENGGUNAAN AIR, PERAKARAN TANAMAN, DAN HASIL TANAMAN PADI

    Directory of Open Access Journals (Sweden)

    Hingdri -

    2013-03-01

    Full Text Available Teknik pengaturan air pada budidaya tanaman padi melalui Intensifikasi Padi Aerob Terkendali-Berbasis Organik (IPAT-BO perlu dilakukan untuk meningkatkan efisiensi penggunaan air. Penelitian ini bertujuan untuk mengtahui aktivitas rhizobacteria, tingkat efisiensi penggunaan air, perkaran tanaman, dan hasil tanaman pada berbagai teknik pengaturan air.Penelitian dilaksanakan di lahan percobaan Fakultas Pertanian Universitas Winaya Mukti, Tanjungsari pada inceptisol pada skala pot plastik. Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK faktor tunggal dengan 16 perlakuan dan diulang tiga kali, yaitu terdiri dari kombinasi antara perlakuan air dan empat varietas. Perlakuan air: tinggi muka air + 5cm, 0 cm, – 5 cm dan  – 10 cm. Empat varietas: Ciherang, Sintanur, Inpari 13 dan Fatmawati..Hasil penelitian menunjukkan terdapat pengaruhnyata terhadap populasi Rhizobacteria, perkembangan akar, dan hasil tanaman. Perlakuan tinggi muka air – 10 cm varietas Fatmawati memberikan hasil tertinggi pada volume akar 186,67 ml, populasi bakteri Azotobacter sp. (1,43 x 1010 CFU g-1, bakteri pelarut fosfat (6,07 x 108 CFU g-1, hasil tanaman tertinggi 95,9 g rumpun-1 setara dengan 9,14 ton ha-1 serta meningkatkan efisiensi penggunaan air 47,1 % dibandingkan dengan pengenangan 5 cm.Kata kunci:  Teknik pengaturan air, efisiensi penggunaan air, IPAT-BO, populasi rhizobakteria

  15. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    De Guzman, Zenaida M. [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Cervancia, Cleofas R. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines, Los Banos, Laguna (Philippines); Dimasuay, Kris Genelyn B.; Tolentino, Mitos M.; Abrera, Gina B.; Cobar, Ma. Lucia C. [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Fajardo, Alejandro C.; Sabino, Noel G.; Manila-Fajardo, Analinda C. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines, Los Banos, Laguna (Philippines); Feliciano, Chitho P., E-mail: cpfeliciano@pnri.dost.gov.ph [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City (Philippines)

    2011-10-15

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a {sup 60}Co source. Surviving spores were counted and used to estimate the decimal reduction (D{sub 10}) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10{sup 5}-9x10{sup 3} spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D{sub min}) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to {gamma}-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials. - Highlights: > We characterized Paenibacillus larvae and determined its radiation sensitivity. > We investigated the effectiveness of gamma rays in inactivating P. larvae. > Gamma radiation inactivates P. larvae. > 15 kGy is effective for the sterilization of P. larvae-infected hives. > Irradiation produces no visible changes in the hives' body, waxes and frames.

  16. Biological Control of Bacterial Fruit Blotch of Watermelon Pathogen (Acidovorax citrulli with Rhizosphere Associated Bacteria

    Directory of Open Access Journals (Sweden)

    Mahesh Adhikari

    2017-04-01

    Full Text Available Bacterial fruit blotch (BFB, which is caused by Acidovorax citrulli, is a serious threat to watermelon growers around the world. The present study was conducted to screen effective rhizobacterial isolates against 35 different A. citrulli isolates and determine their efficacy on BFB and growth parameters of watermelon. Two rhizobacterial isolates viz. Paenibacillus polymyxa (SN-22, Sinomonas atrocyanea (NSB-27 showed high inhibitory activity in the preliminary screening and were further evaluated for their effect on BFB and growth parameters of three different watermelon varieties under greenhouse conditions. The greenhouse experiment result revealed that SN-22 and NSB-27 significantly reduced BFB and had significant stimulatory effect on total chlorophyll content, plant height, total fresh weight and total dry weight compared to uninoculated plants across the tested three watermelon varieties. Analysis of the 16S ribosomal RNA (rRNA sequences revealed that strains SN-22 belong to P. polymyxa and NSB-27 to S. atrocyanea with the bootstrap value of 99% and 98%, respectively. The isolates SN-22 and NSB-27 were tested for antagonistic and PGP traits. The result showed that the tested isolates produced siderophore, hydrolytic enzymes (protease and cellulose, chitinase, starch hydrolytic enzymes and they showed phosphate as well as zinc solubilizing capacity. This is the first report of P. polymyxa (SN-22 and S. atrocyanea (NSB-27 as biocontrol-plant growth promoting rhizobacteria on watermelon.

  17. Potential of Finger Millet Indigenous Rhizobacterium Pseudomonas sp. MSSRFD41 in Blast Disease Management—Growth Promotion and Compatibility With the Resident Rhizomicrobiome

    Directory of Open Access Journals (Sweden)

    Jegan Sekar

    2018-05-01

    Full Text Available Finger millet [Eleusine coracona (L. Gaertner] “Ragi” is a nutri-cereal with potential health benefits, and is utilized solely for human consumption in semi-arid regions of Asia and Africa. It is highly vulnerable to blast disease caused by Pyricularia grisea, resulting in 50–100% yield loss. Chemical fungicides are used for the management of blast disease, but with great safety concern. Alternatively, bioinoculants are widely used in promoting seedling efficiency, plant biomass, and disease control. Little is known about the impact of introduced indigenous beneficial rhizobacteria on the rhizosphere microbiota and growth promotion in finger millet. Strain MSSRFD41 exhibited a 22.35 mm zone of inhibition against P. grisea, produces antifungal metabolites, siderophores, hydrolytic enzymes, and IAA, and solubilizes phosphate. Environmental SEM analysis indicated the potential of MSSRFD41 to inhibit the growth of P. grisea by affecting cellular functions, which caused deformation in fungal hyphae. Bioprimed finger millet seeds exhibited significantly higher levels of germination, seedling vigor index, and enhanced shoot and root length compared to control seeds. Cross streaking and RAPD analysis showed that MSSRFD41 is compatible with different groups of rhizobacteria and survived in the rhizosphere. In addition, PLFA analysis revealed no significant difference in microbial biomass between the treated and control rhizosphere samples. Field trials showed that MSSRFD41 treatment significantly reduced blast infestation and enhanced plant growth compared to other treatments. A liquid formulated MSSRFD41 product maintained shelf life at an average of 108 CFU ml−1 over 150 days of storage at 25°C. Overall, results from this study demonstrated that Pseudomonas sp. MSSRFD41, an indigenous rhizobacterial strain, is an alternative, effective, and sustainable resource for the management of P. grisea infestation and growth promotion of finger millet.

  18. Potential of Finger Millet Indigenous Rhizobacterium Pseudomonas sp. MSSRFD41 in Blast Disease Management—Growth Promotion and Compatibility With the Resident Rhizomicrobiome

    Science.gov (United States)

    Sekar, Jegan; Raju, Kathiravan; Duraisamy, Purushothaman; Ramalingam Vaiyapuri, Prabavathy

    2018-01-01

    Finger millet [Eleusine coracona (L). Gaertner] “Ragi” is a nutri-cereal with potential health benefits, and is utilized solely for human consumption in semi-arid regions of Asia and Africa. It is highly vulnerable to blast disease caused by Pyricularia grisea, resulting in 50–100% yield loss. Chemical fungicides are used for the management of blast disease, but with great safety concern. Alternatively, bioinoculants are widely used in promoting seedling efficiency, plant biomass, and disease control. Little is known about the impact of introduced indigenous beneficial rhizobacteria on the rhizosphere microbiota and growth promotion in finger millet. Strain MSSRFD41 exhibited a 22.35 mm zone of inhibition against P. grisea, produces antifungal metabolites, siderophores, hydrolytic enzymes, and IAA, and solubilizes phosphate. Environmental SEM analysis indicated the potential of MSSRFD41 to inhibit the growth of P. grisea by affecting cellular functions, which caused deformation in fungal hyphae. Bioprimed finger millet seeds exhibited significantly higher levels of germination, seedling vigor index, and enhanced shoot and root length compared to control seeds. Cross streaking and RAPD analysis showed that MSSRFD41 is compatible with different groups of rhizobacteria and survived in the rhizosphere. In addition, PLFA analysis revealed no significant difference in microbial biomass between the treated and control rhizosphere samples. Field trials showed that MSSRFD41 treatment significantly reduced blast infestation and enhanced plant growth compared to other treatments. A liquid formulated MSSRFD41 product maintained shelf life at an average of 108 CFU ml−1 over 150 days of storage at 25°C. Overall, results from this study demonstrated that Pseudomonas sp. MSSRFD41, an indigenous rhizobacterial strain, is an alternative, effective, and sustainable resource for the management of P. grisea infestation and growth promotion of finger millet. PMID:29875748

  19. Potential of Finger Millet Indigenous Rhizobacterium Pseudomonas sp. MSSRFD41 in Blast Disease Management-Growth Promotion and Compatibility With the Resident Rhizomicrobiome.

    Science.gov (United States)

    Sekar, Jegan; Raju, Kathiravan; Duraisamy, Purushothaman; Ramalingam Vaiyapuri, Prabavathy

    2018-01-01

    Finger millet [ Eleusine coracona (L). Gaertner] "Ragi" is a nutri-cereal with potential health benefits, and is utilized solely for human consumption in semi-arid regions of Asia and Africa. It is highly vulnerable to blast disease caused by Pyricularia grisea , resulting in 50-100% yield loss. Chemical fungicides are used for the management of blast disease, but with great safety concern. Alternatively, bioinoculants are widely used in promoting seedling efficiency, plant biomass, and disease control. Little is known about the impact of introduced indigenous beneficial rhizobacteria on the rhizosphere microbiota and growth promotion in finger millet. Strain MSSRFD41 exhibited a 22.35 mm zone of inhibition against P. grisea , produces antifungal metabolites, siderophores, hydrolytic enzymes, and IAA, and solubilizes phosphate. Environmental SEM analysis indicated the potential of MSSRFD41 to inhibit the growth of P. grisea by affecting cellular functions, which caused deformation in fungal hyphae. Bioprimed finger millet seeds exhibited significantly higher levels of germination, seedling vigor index, and enhanced shoot and root length compared to control seeds. Cross streaking and RAPD analysis showed that MSSRFD41 is compatible with different groups of rhizobacteria and survived in the rhizosphere. In addition, PLFA analysis revealed no significant difference in microbial biomass between the treated and control rhizosphere samples. Field trials showed that MSSRFD41 treatment significantly reduced blast infestation and enhanced plant growth compared to other treatments. A liquid formulated MSSRFD41 product maintained shelf life at an average of 10 8 CFU ml -1 over 150 days of storage at 25°C. Overall, results from this study demonstrated that Pseudomonas sp. MSSRFD41, an indigenous rhizobacterial strain, is an alternative, effective, and sustainable resource for the management of P. grisea infestation and growth promotion of finger millet.

  20. Understanding the molecular basis of plant growth promotional effect of Pseudomonas fluorescens on rice through protein profiling

    Directory of Open Access Journals (Sweden)

    Thiruvengadam Raguchander

    2009-12-01

    Full Text Available Abstract Background Plant Growth Promoting Rhizobacteria (PGPR, Pseudomonas fluorescens strain KH-1 was found to exhibit plant growth promotional activity in rice under both in-vitro and in-vivo conditions. But the mechanism underlying such promotional activity of P. fluorescens is not yet understood clearly. In this study, efforts were made to elucidate the molecular responses of rice plants to P. fluorescens treatment through protein profiling. Two-dimensional polyacrylamide gel electrophoresis strategy was adopted to identify the PGPR responsive proteins and the differentially expressed proteins were analyzed by mass spectrometry. Results Priming of P. fluorescens, 23 different proteins found to be differentially expressed in rice leaf sheaths and MS analysis revealed the differential expression of some important proteins namely putative p23 co-chaperone, Thioredoxin h- rice, Ribulose-bisphosphate carboxylase large chain precursor, Nucleotide diPhosphate kinase, Proteosome sub unit protein and putative glutathione S-transferase protein. Conclusion Functional analyses of the differential proteins were reported to be directly or indirectly involved in growth promotion in plants. Thus, this study confirms the primary role of PGPR strain KH-1 in rice plant growth promotion.

  1. Paenilarvins: Iturin family lipopeptides from the honey bee pathogen Paenibacillus larvae.

    Science.gov (United States)

    Sood, Sakshi; Steinmetz, Heinrich; Beims, Hannes; Mohr, Kathrin I; Stadler, Marc; Djukic, Marvin; von der Ohe, Werner; Steinert, Michael; Daniel, Rolf; Müller, Rolf

    2014-09-05

    The bacterium Paenibacillus larvae has been extensively studied as it is an appalling honey bee pathogen. In the present work, we screened crude extracts derived from fermentations of P. larvae genotypes ERIC I and II for antimicrobial activity, following the detection of four putative secondary metabolite gene clusters that show high sequence homology to known biosynthetic gene clusters for the biosynthesis of antibiotics. Low molecular weight metabolites produced by P. larvae have recently been shown to have toxic effects on honey bee larvae. Moreover, a novel tripeptide, sevadicin, was recently characterized from laboratory cultures of P. larvae. In this study, paenilarvins, which are iturinic lipopeptides exhibiting strong antifungal activities, were obtained by bioassay-guided fractionation from cultures of P. larvae, genotype ERIC II. Their molecular structures were determined by extensive 2D NMR spectroscopy, high resolution mass spectrometry, and other methods. Paenilarvins are the first antifungal secondary metabolites to be identified from P. larvae. In preliminary experiments, these lipopeptides also affected honey bee larvae and might thus play a role in P. larvae survival and pathogenesis. However, further studies are needed to investigate their function. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Rhizobacteria and plant symbiosis in heavy metal uptake and its implications for soil bioremediation.

    Science.gov (United States)

    Sobariu, Dana Luminița; Fertu, Daniela Ionela Tudorache; Diaconu, Mariana; Pavel, Lucian Vasile; Hlihor, Raluca-Maria; Drăgoi, Elena Niculina; Curteanu, Silvia; Lenz, Markus; Corvini, Philippe François-Xavier; Gavrilescu, Maria

    2017-10-25

    Certain species of plants can benefit from synergistic effects with plant growth-promoting rhizobacteria (PGPR) that improve plant growth and metal accumulation, mitigating toxic effects on plants and increasing their tolerance to heavy metals. The application of PGPR as biofertilizers and atmospheric nitrogen fixators contributes considerably to the intensification of the phytoremediation process. In this paper, we have built a system consisting of rhizospheric Azotobacter microbial populations and Lepidium sativum plants, growing in solutions containing heavy metals in various concentrations. We examined the ability of the organisms to grow in symbiosis so as to stimulate the plant growth and enhance its tolerance to Cr(VI) and Cd(II), to ultimately provide a reliable phytoremediation system. The study was developed at the laboratory level and, at this stage, does not assess the inherent interactions under real conditions occurring in contaminated fields with autochthonous microflora and under different pedoclimatic conditions and environmental stresses. Azotobacter sp. bacteria could indeed stimulate the average germination efficiency of Lepidium sativum by almost 7%, average root length by 22%, average stem length by 34% and dry biomass by 53%. The growth of L. sativum has been affected to a greater extent in Cd(II) solutions due its higher toxicity compared to that of Cr(VI). The reduced tolerance index (TI, %) indicated that plant growth in symbiosis with PGPR was however affected by heavy metal toxicity, while the tolerance of the plant to heavy metals was enhanced in the bacteria-plant system. A methodology based on artificial neural networks (ANNs) and differential evolution (DE), specifically a neuro-evolutionary approach, was applied to model germination rates, dry biomass and root/stem length and proving the robustness of the experimental data. The errors associated with all four variables are small and the correlation coefficients higher than 0

  3. Gene cluster analysis for the biosynthesis of elgicins, novel lantibiotics produced by paenibacillus elgii B69

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    Teng Yi

    2012-03-01

    Full Text Available Abstract Background The recent increase in bacterial resistance to antibiotics has promoted the exploration of novel antibacterial materials. As a result, many researchers are undertaking work to identify new lantibiotics because of their potent antimicrobial activities. The objective of this study was to provide details of a lantibiotic-like gene cluster in Paenibacillus elgii B69 and to produce the antibacterial substances coded by this gene cluster based on culture screening. Results Analysis of the P. elgii B69 genome sequence revealed the presence of a lantibiotic-like gene cluster composed of five open reading frames (elgT1, elgC, elgT2, elgB, and elgA. Screening of culture extracts for active substances possessing the predicted properties of the encoded product led to the isolation of four novel peptides (elgicins AI, AII, B, and C with a broad inhibitory spectrum. The molecular weights of these peptides were 4536, 4593, 4706, and 4820 Da, respectively. The N-terminal sequence of elgicin B was Leu-Gly-Asp-Tyr, which corresponded to the partial sequence of the peptide ElgA encoded by elgA. Edman degradation suggested that the product elgicin B is derived from ElgA. By correlating the results of electrospray ionization-mass spectrometry analyses of elgicins AI, AII, and C, these peptides are deduced to have originated from the same precursor, ElgA. Conclusions A novel lantibiotic-like gene cluster was shown to be present in P. elgii B69. Four new lantibiotics with a broad inhibitory spectrum were isolated, and these appear to be promising antibacterial agents.

  4. Evaluation of the plant growth-promoting activity of Pseudomonas nitroreducens in Arabidopsis thaliana and Lactuca sativa.

    Science.gov (United States)

    Trinh, Cao Son; Lee, Hyeri; Lee, Won Je; Lee, Seok Jin; Chung, Namhyun; Han, Juhyeong; Kim, Jongyun; Hong, Suk-Whan; Lee, Hojoung

    2018-06-01

    Pseudomonas nitroreducens: strain IHB B 13561 (PnIHB) enhances the growth of Arabidopsis thaliana and Lactuca sativa via the stimulation of cell development and nitrate absorption. Plant growth-promoting rhizobacteria (PGPR) enhance plant development through various mechanisms; they improve the uptake of soil resources by plants to greatly promote plant growth. Here, we used Arabidopsis thaliana seedlings and Lactuca sativa to screen the growth enhancement activities of a purified PGPR, Pseudomonas nitroreducens strain IHB B 13561 (PnIHB). When cocultivated with PnIHB, both species of plants exhibited notably improved growth, particularly in regard to biomass. Quantitative reverse transcription polymerase chain reaction analysis indicated high expression levels of the nitrate transporter genes, especially NRT2.1, which plays a major role in the high-affinity nitrate transport system in roots. Moreover, enhanced activity of the cyclin-B1 promoter was observed when wild-type 'Columbia-0' Arabidopsis seedlings were exposed to PnIHB, whereas upregulation of cyclin-B also occurred in the inoculated lettuce seedlings. Overall, these results suggest that PnIHB improves A. thaliana and L. sativa growth via specific pathways involved in the promotion of cell development and enhancement of nitrate uptake.

  5. Optimal Concentration of Organic Solvents to be Used in the Broth Microdilution Method to Determine the Antimicrobial Activity of Natural Products Against Paenibacillus Larvae

    OpenAIRE

    Cugnata Noelia Melina; Guaspari Elisa; Pellegrini Maria Celeste; Fuselli Sandra Rosa; Alonso-Salces Rosa Maria

    2017-01-01

    American Foulbrood (AFB) is a bacterial disease, caused by Paenibacillus larvae, that affects honeybees (Apis mellifera). Alternative strategies to control AFB are based on the treatment of the beehives with antimicrobial natural substances such as extracts, essential oils and/or pure compounds from plants, honey by-products, bacteria and moulds. The broth microdilution method is currently one of the most widely used methods to determine the minimum inhibitory concentration (MIC) of a substan...

  6. The genome of Paenibacillus sabinae T27 provides insight into evolution, organization and functional elucidation of nif and nif-like genes

    OpenAIRE

    Li, Xinxin; Deng, Zhiping; Liu, Zhanzhi; Yan, Yongliang; Wang, Tianshu; Xie, Jianbo; Lin, Min; Cheng, Qi; Chen, Sanfeng

    2014-01-01

    Background Most biological nitrogen fixation is catalyzed by the molybdenum nitrogenase. This enzyme is a complex which contains the MoFe protein encoded by nifDK and the Fe protein encoded by nifH. In addition to nifHDK, nifHDK-like genes were found in some Archaea and Firmicutes, but their function is unclear. Results We sequenced the genome of Paenibacillus sabinae T27. A total of 4,793 open reading frames were predicted from its 5.27 Mb genome. The genome of P. sabinae T27 contains fiftee...

  7. Two choices for the functionalization of silica nanoparticles with gallic acid: characterization of the nanomaterials and their antimicrobial activity against Paenibacillus larvae

    Science.gov (United States)

    Vico, Tamara A.; Arce, Valeria B.; Fangio, María F.; Gende, Liesel B.; Bertran, Celso A.; Mártire, Daniel O.; Churio, María S.

    2016-11-01

    Silica nanoparticles attached to gallic acid were synthesized from 7-nm diameter fumed silica particles by different functionalization methods involving the condensation of hydroxyl or carboxyl groups. The particles were characterized by thermal analyses and UV-vis, FTIR, NMR, and EPR spectroscopies. In comparison to free gallic acid, enhanced stability and increased antimicrobial activity against Paenibacillus larvae were found for the functionalized nanoparticles. Thus, both derivatization strategies result in improved properties of the natural polyphenol as antimicrobial agent for the treatment of honeybee pathologies.

  8. Two choices for the functionalization of silica nanoparticles with gallic acid: characterization of the nanomaterials and their antimicrobial activity against Paenibacillus larvae

    International Nuclear Information System (INIS)

    Vico, Tamara A.; Arce, Valeria B.; Fangio, María F.; Gende, Liesel B.; Bertran, Celso A.; Mártire, Daniel O.; Churio, María S.

    2016-01-01

    Silica nanoparticles attached to gallic acid were synthesized from 7-nm diameter fumed silica particles by different functionalization methods involving the condensation of hydroxyl or carboxyl groups. The particles were characterized by thermal analyses and UV–vis, FTIR, NMR, and EPR spectroscopies. In comparison to free gallic acid, enhanced stability and increased antimicrobial activity against Paenibacillus larvae were found for the functionalized nanoparticles. Thus, both derivatization strategies result in improved properties of the natural polyphenol as antimicrobial agent for the treatment of honeybee pathologies.

  9. Two choices for the functionalization of silica nanoparticles with gallic acid: characterization of the nanomaterials and their antimicrobial activity against Paenibacillus larvae

    Energy Technology Data Exchange (ETDEWEB)

    Vico, Tamara A. [Universidad Nacional de Mar del Plata, Departamento de Química, FCEyN/IFIMAR, CONICET (Argentina); Arce, Valeria B. [CONICET La Plata—CIC—UNLP, Centro de Investigaciones Ópticas (CIOp) (Argentina); Fangio, María F., E-mail: mfangio@mdp.edu.ar [Universidad Nacional de Mar del Plata, Departamento de Química, FCEyN/IFIMAR, CONICET (Argentina); Gende, Liesel B. [Universidad Nacional de Mar del Plata, Centro de Investigaciones en Abejas Sociales, FCEyN (Argentina); Bertran, Celso A. [University of Campinas, Chemistry Institute (Brazil); Mártire, Daniel O. [Universidad Nacional de La Plata, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CONICET (Argentina); Churio, María S., E-mail: schurio@mdp.edu.ar [Universidad Nacional de Mar del Plata, Departamento de Química, FCEyN/IFIMAR, CONICET (Argentina)

    2016-11-15

    Silica nanoparticles attached to gallic acid were synthesized from 7-nm diameter fumed silica particles by different functionalization methods involving the condensation of hydroxyl or carboxyl groups. The particles were characterized by thermal analyses and UV–vis, FTIR, NMR, and EPR spectroscopies. In comparison to free gallic acid, enhanced stability and increased antimicrobial activity against Paenibacillus larvae were found for the functionalized nanoparticles. Thus, both derivatization strategies result in improved properties of the natural polyphenol as antimicrobial agent for the treatment of honeybee pathologies.

  10. Assessment of root-associated paenibacillus polymyxa groups on growth promotion and induced systemic resistance in pepper.

    Science.gov (United States)

    Phi, Quyet-Tien; Park, Yu-Mi; Seul, Keyung-Jo; Ryu, Choong-Min; Park, Seung-Hwan; Kim, Jong-Guk; Ghim, Sa-Youl

    2010-12-01

    Twenty-nine P. polymyxa strains isolated from rhizospheres of various crops were clustered into five genotypic groups on the basis of BOX-PCR analysis. The characteristics of several plant growth-promoting factors among the isolates revealed the distinct attributes in each allocated group. Under gnotobiotic conditions, inoculation of pepper roots with P. polymyxa isolates significantly increased the biomass in 17 of total 29 treated plants with untreated plants. Experiments on induced systemic resistance (ISR) against bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria in pepper by P. polymyxa strains were conducted and only one isolate (KNUC265) was selected. Further studies into ISR mediation by the KNUC265 strain against the soft-rot pathogen Erwinia carotovora subsp. carotovora in tobacco demonstrated that the tobacco seedlings exposed to either bacterial volatiles or diffusible metabolites exhibited a reduction in disease severity. In conclusion, ISR and plant growth promotion triggered by P. polymyxa isolates were systemically investigated on pepper for the first time. The P. polymyxa KNUC265 strain, which elicited both ISR and plant growth promotion, could be potentially used in improving the yield of pepper and possibly of other crops.

  11. Lethal infection thresholds of Paenibacillus larvae for honeybee drone and worker larvae (Apis mellifera).

    Science.gov (United States)

    Behrens, Dieter; Forsgren, Eva; Fries, Ingemar; Moritz, Robin F A

    2010-10-01

    We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  12. Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops

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    Hassan Etesami

    2018-02-01

    Full Text Available Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.

  13. Required characteristics of Paenibacillus polymyxa JB-0501 as potential probiotic.

    Science.gov (United States)

    Naghmouchi, Karim; Baah, John; Cudennec, Benoit; Drider, Djamel

    2013-08-01

    The ability of Paenibacillus polymyxa to inhibit the growth of Escherichia coli generic ATCC 25922 (Escherichia coli ATCC 25922) and to adhere to monolayers of the enterocyte-like human cell line Caco-2 was evaluated. P. polymyxa JB-0501 (P. polymyxa JB-0501), found in a livestock feed probiotic supplement, was compared to P. polymyxa reference strain ATCC 43685 and ATCC 7070 (P. polymyxa ATCC) in terms of carbohydrate utilization and resistance to lysozyme, acid, bile salts, and hydrogen peroxide. JB-0501 grew at pH 4.5 and at H2O2 concentrations less than 7.3 μg/ml and presented a higher affinity to hexadecane and decane. Bile salts at 0.2 % inhibited the growth of all three strains. P. polymyxa JB-0501 and P. polymyxa ATCC 43865 adhered to Caco-2 cell monolayers. The percentage of cells that adhered ranged from about 0.35 to 6.5 % and was partially proportional to the number applied. Contact time (from 15 min to 1 h) had little impact on adhesion. P. polymyxa JB-0501 inhibited the growth of E. coli ATCC 25922, as proven by the diffusion tests in agar. Taken together, these results suggested that P. polymyxa JB-0501 has the potential probiotic properties to justify its consideration as a livestock feed supplement.

  14. Use of rhizobacteria and endophytes for biological control of weeds

    Directory of Open Access Journals (Sweden)

    Trognitz, Friederike

    2014-02-01

    Full Text Available Weeds cause severe yield losses in agriculture, with a maximum estimate of 34% of yield loss worldwide due to competition between the crops and the weeds for nutrition, light and humidity (OERKE, 2006. Invasive plants contribute partially to other problems. The pollen of common ragweed, Ambrosia artemisiifolia L., for example, is five times more allergenic than grass pollen; already ten pollen grains per m3 air can trigger allergy in sensitized patients, including rhinitis, conjunctivitis and asthma. This neophyte from America has extended the season of allergy in European patients to October. Common ragweed is currently most frequent in Hungary, France and Italy. In Austria, ragweed populations along roads have increased dramatically since 2000. The effective means to control this weed of the Asteraceae family are limited; a single plant can produce up to 6000 seeds which stay in the soil for 40 years. Control using selective herbicides is not possible within stands of the Asteraceae member sunflower. Efforts to use herbivore insects as biological control agents also failed due to the unavailability of insects specializing on this ragweed. The use of plant-associated rhizobacteria and endophytes as bio-herbicides offers a novel alternative to conventional methods. By analogy to experiences from other plant-microbe systems, the chances to find microbes of the desired characteristics are highest when isolating and testing specimens directly from ragweed plants. These organisms often have an extremely narrow host range that permits their use for the control of among several even closely related plant species growing together in a field.

  15. Medium Optimization for the Production of Fibrinolytic Enzyme by Paenibacillus sp. IND8 Using Response Surface Methodology

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    Ponnuswamy Vijayaraghavan

    2014-01-01

    Full Text Available Production of fibrinolytic enzyme by a newly isolated Paenibacillus sp. IND8 was optimized using wheat bran in solid state fermentation. A 25 full factorial design (first-order model was applied to elucidate the key factors as moisture, pH, sucrose, yeast extract, and sodium dihydrogen phosphate. Statistical analysis of the results has shown that moisture, sucrose, and sodium dihydrogen phosphate have the most significant effects on fibrinolytic enzymes production (P<0.05. Central composite design (CCD was used to determine the optimal concentrations of these three components and the experimental results were fitted with a second-order polynomial model at 95% level (P<0.05. Overall, 4.5-fold increase in fibrinolytic enzyme production was achieved in the optimized medium as compared with the unoptimized medium.

  16. Potential for plant growth promotion of rhizobacteria associated with Salicornia growing in Tunisian hypersaline soils.

    Science.gov (United States)

    Mapelli, Francesca; Marasco, Ramona; Rolli, Eleonora; Barbato, Marta; Cherif, Hanene; Guesmi, Amel; Ouzari, Imen; Daffonchio, Daniele; Borin, Sara

    2013-01-01

    Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

  17. Potential for Plant Growth Promotion of Rhizobacteria Associated with Salicornia Growing in Tunisian Hypersaline Soils

    Directory of Open Access Journals (Sweden)

    Francesca Mapelli

    2013-01-01

    Full Text Available Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

  18. Plant growth promotion rhizobacteria in onion production.

    Science.gov (United States)

    Colo, Josip; Hajnal-Jafari, Timea I; Durić, Simonida; Stamenov, Dragana; Hamidović, Saud

    2014-01-01

    The aim of the research was to examine the effect of rhizospheric bacteria Azotobacter chroococcum, Pseudomonas fluorescens (strains 1 and 2) and Bacillus subtilis on the growth and yield of onion and on the microorganisms in the rhizosphere of onion. The ability of microorganisms to produce indole-acetic acid (IAA), siderophores and to solubilize tricalcium phosphate (TCP) was also assessed. The experiment was conducted in field conditions, in chernozem type of soil. Bacillus subtilis was the best producer of IAA, whereas Pseudomonas fluorescens strains were better at producing siderophores and solubilizing phosphates. The longest seedling was observed with the application of Azotobacter chroococcum. The height of the plants sixty days after sowing was greater in all the inoculated variants than in the control. The highest onion yield was observed in Bacillus subtilis and Azotobacter chroococcum variants. The total number of bacteria and the number of Azotobacter chroococcum were larger in all the inoculated variants then in the control. The number of fungi decreased in most of the inoculated variants, whereas the number of actinomycetes decreased or remained the same.

  19. Bioconversion of wastewater from sweet potato starch production to Paenibacillus polymyxa biofertilizer for tea plants.

    Science.gov (United States)

    Xu, Shengjun; Bai, Zhihui; Jin, Bo; Xiao, Runlin; Zhuang, Guoqiang

    2014-02-28

    Wastewater from the sweet potato starch industry is a large source of nutrient-rich substrates. We assessed whether this wastewater could be used to produce Paenibacillus polymyxa biofertilizer for foliar application to tea trees. Using the central composite design methods we experientially determined that the optimal culture conditions for P. polymyxa were pH, 6.5; temperature, 29.0 °C; and incubation time, 16 h. Under these conditions, a maximum biomass of 9.7 × 10(9) cfu/mL was achieved. We then conducted a yearlong field investigation to determine the effect of P. polymyxa biofertilizer on the growth of tea plants (Camellia sinensis). Tea yield, quantity of water extract, and tea polyphenol levels were significantly higher after foliar application of the biofertilizer compared to that in the controls by an average of 16.7%, 6.3%, and 10.4%, respectively. This approach appears to be technically feasible for organic tea production, and is an environmentally friendly way to utilize wastewater.

  20. Effect of immobilized rhizobacteria and organic amendment in bulk and rhizospheric soil of Cistus albidus L.

    Science.gov (United States)

    Mengual, Carmen Maria; del Mar Alguacil, Maria; Roldan, Antonio; Schoebitz, Mauricio

    2013-04-01

    A field experiment was carried out to assess the effectiveness of the immobilized microbial inoculant and the addition of organic olive residue. The microbial inoculant contained two rhizobacterial species identified as Azospirillum brasilense and Pantoea dispersa immobilized in a natural inert support. Bacterial population densities were 3.5×109 and 4.1×109 CFU g-1 of A. brasilense M3 and P. dispersa C3, respectively. The amendment used was the organic fraction extracted with KOH from composted "alperujo". The raw material was collected from an olive-mill and mixed with fresh cow bedding as bulking agent for composting. The inoculation of rhizobacteria and the addition of organic residue were employed for plant growth promotion of Cistus albidus L. and enhancement of soil physicochemical, biochemical and biological properties in a degraded semiarid Mediterranean area. One year after planting, the available phosphorus and potassium content in the amended soils was about 100 and 70% respectively higher than in the non-amended soil. Microbial inoculant and their interaction with organic residue increased the aggregate stability of the rhizosphere soil of C. albidus (by 12% with respect to control soil) while the organic residue alone not increased the aggregate stability of the rhizosphere of C. albidus. Microbial biomass C content and enzyme activities (dehydrogenase, urease, protease-BAA and alkaline phosphatase) of the rhizosphere of C. albidus were increased by microbial inoculant and organic residue interaction but not by microbial inoculation alone. The microbial inoculant and organic residue interaction were the most effective treatment for stimulating the roots dry weight of C. albidus (by 133% with respect to control plants) and microbial inoculant was the most effective treatment for increase the shoot dry weigh of plants (by 106% with respect to control plants). The combined treatment, involving microbial inoculant and addition of the organic residue

  1. Isolation and identification of Paenibacillus sp. FM-6, involved in the biotransformation of albendazole.

    Science.gov (United States)

    Jin, Lei; Zhang, Xiaojun; Sun, Xiumei; Shi, Hui; Li, Tiejun

    2014-10-01

    A strain, designated as FM-6, was isolated from fish. Based on the results of phenotypic, physiological characteristics, genotypic and phylogenetic analysis, strain FM-6 was finally identified as Paenibacillus sp. When albendazole was provided as the sole carbon source, strain FM-6 could grow and transform albendazole. About 82.7 % albendazole (50 mg/L) was transformed by strain FM-6 after 5 days incubation at 30 °C, 160 rpm. With HPLC-MS method, the transforming product of albendazole was researched. Based on the molecular weight and the retention time, product was identified as albendazole sulfoxide and the transforming pathway of albendazole by strain FM-6 was proposed finally. The optimum temperature and pH for the bacterium growth and albendazole transformation by strain FM-6 were both 30 °C and 7.0. Moreover, the optimum concentration of albendazole for the bacterium growth was 50 mg/L. Coupled with practical production, 50 mg/L was the optimum concentration of albendazole transformation for strain FM-6. This study highlights an important potential use of strain FM-6 for producing albendazole sulfoxide.

  2. Purification, gene cloning, and biochemical characterization of a β-glucosidase capable of hydrolyzing sesaminol triglucoside from Paenibacillus sp. KB0549.

    Directory of Open Access Journals (Sweden)

    Arun Nair

    Full Text Available The triglucoside of sesaminol, i.e., 2,6-O-di(β-D-glucopyranosyl-β-D- glucopyranosylsesaminol (STG, occurs abundantly in sesame seeds and sesame oil cake and serves as an inexpensive source for the industrial production of sesaminol, an anti-oxidant that displays a number of bioactivities beneficial to human health. However, STG has been shown to be highly resistant to the action of β-glucosidases, in part due to its branched-chain glycon structure, and these circumstances hampered the efficient utilization of STG. We found that a strain (KB0549 of the genus Paenibacillus produced a novel enzyme capable of efficiently hydrolyzing STG. This enzyme, termed PSTG, was a tetrameric protein consisting of identical subunits with an approximate molecular mass of 80 kDa. The PSTG gene was cloned on the basis of the partial amino acid sequences of the purified enzyme. Sequence comparison showed that the enzyme belonged to the glycoside hydrolase family 3, with significant similarities to the Paenibacillus glucocerebrosidase (63% identity and to Bgl3B of Thermotoga neapolitana (37% identity. The recombinant enzyme (rPSTG was highly specific for β-glucosidic linkage, and k cat and k cat/K m values for the rPSTG-catalyzed hydrolysis of p-nitrophenyl-β-glucopyraniside at 37°C and pH 6.5 were 44 s(-1 and 426 s(-1 mM(-1, respectively. The specificity analyses also revealed that the enzyme acted more efficiently on sophorose than on cellobiose and gentiobiose. Thus, rPSTG is the first example of a β-glucosidase with higher reactivity for β-1,2-glucosidic linkage than for β-1,4- and β-1,6-glucosidic linkages, as far as could be ascertained. This unique specificity is, at least in part, responsible for the enzyme's ability to efficiently decompose STG.

  3. Phytoremediation of heavy metals with several efficiency enhancer ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... Key words: phytoremediation, heavy metal, plant growth promoting rhizobacteria, multi-functional method. ... population in the twentieth century, heavy metal ... This natural and environmental friendly technology is.

  4. Response of rice to inoculation with plant growth promoting rhizobacteria in control lab environment and field experiment

    International Nuclear Information System (INIS)

    Ahmed, B.

    2014-01-01

    The present study was conducted to evaluate the effects of bacterial inoculation on different growth parameters of rice variety JP-5. Three bacterial strains (Azospirillum brasilense R1, Azospirillum lipoferum RSWT1 and Pseudomonas Ky1) were used to inoculate rice varietyJP-5 at control lab environment and field. Plant growth promotion was observed in all inoculated treatments over non-inoculated, which was evident from increase in root area, root length, number of tillers, straw and grain yields and total weight of plant. Azospirillum brasilense R1 was more effective in plant growth promotion than other strains and showed 19% increase in the straw weight and 39.5% increase in grain weight. Inoculation with Azospirillum lipoferum RSWT1 and Pseudomonas Ky1 increased grain weight by 18.5% and 13.8% respectively. The study revealed that beneficial strains of PGPR can be used as biofertilizer for rice. (author)

  5. Isolation and characterization of a plant growth-promoting rhizobacterium, Serratia sp. SY5.

    Science.gov (United States)

    Koo, So-Yeon; Cho, Kyung-Suk

    2009-11-01

    The role of plant growth-promoting rhizobacteria (PGPR) in the phytoremediation of heavy-metal-contaminated soils is important in overcoming its limitations for field application. A plant growth-promoting rhizobacterium, Serratia sp. SY5, was isolated from the rhizoplane of barnyard grass (Echinochloa crus-galli) grown in petroleum and heavy-metal-contaminated soil. This isolate has shown capacities for indole acetic acid production and siderophores synthesis. Compared with a non-inoculated control, the radicular root growth of Zea mays seedlings inoculated with SY5 can be increased by 27- or 15.4-fold in the presence of 15 mg-Cd/l or 15 mg-Cu/l, respectively. The results from hydroponic cultures showed that inoculation of Serratia sp. SY5 had a favorable influence on the initial shoot growth and biomass of Zea mays under noncontaminated conditions. However, under Cd-contaminated conditions, the inoculation of SY5 significantly increased the root biomass of Zea mays. These results indicate that Serratia sp. SY5 can serve as a promising microbial inoculant for increased plant growth in heavy-metal-contaminated soils to improve the phytoremediation efficiency.

  6. Identification and Characterisation of a Pectinolytic Enzyme from Paenibacillus xylanolyticus

    Directory of Open Access Journals (Sweden)

    Simona Giacobbe

    2014-06-01

    Full Text Available Pectinolytic enzymes play an important role in the processing of lignocellulosic materials because of their ability to improve the access of cellulases to their substrate by removing pectins. The strain Paenibacillus xylanolyticus 2-6L3 was isolated from mature compost obtained from agro-industrial wastes, and the enzyme pectate lyase from P. xylanolyticus 2-6L3, named PaenxylPel, was partially purified and subjected to structural and functional characterisation. The enzyme exhibited an optimum temperature between 60 and 70 °C and optimal pH value of 9.0 for its pectinase activity on pectin from citrus fruit. PaenxylPel showed a thermoresistance and pH resistance higher than those of other pectate lyases so far described, with half-lives of 48 and 24 h at 60 and 70 °C, respectively, a retention of around 80% of activity after 96 h at 40 and 50 °C, and a half-life of about 15 days at pH 8.0. PaenxylPel followed Michaelis-Menten kinetics toward pectin from citrus fruit, pectin from sugar beet pulp, high-ester pectin extracted from citrus peel (> 50% esterified, and polygalacturonic acid (PLA. The ability to act on both PLA and highly methylated pectins, together with a double peak in the graph of optimum pH at pH 5 and 9, suggest that pectate lyase from P. xylanolyticus shows an unusual activity, combining traits of pectate lyase and pectin lyase. This is the first manuscript on the pectinolytic activity of P. xylanolyticus.

  7. DETECTION OF PAENIBACILLUS LARVAE SPORES IN HONEY SAMPLES FROM BEEKEEPERS OF THE CENTRAL REGION OF ALGERIA

    Directory of Open Access Journals (Sweden)

    Adjlane Noureddine

    2013-08-01

    Full Text Available The American foulbrood in one of the most serious diseases that may affect brood of larvae and pupae stages, which cause economic losses and biological hazards in a large beekeeping sector in several countries across the world in general and Algeria in particular. The causative agent of this disease is a bacterium called Paenibacillus larvae that target bees Apis mellifera the latter are often present in honey.The aim of this project is studying the spread of this disease in the northern region of Algeria through the analysis of honey obtained from these areas. Microbiological, microscopic and biochemical methods were used in this study. The results obtained have shown that the prevalence rate varies from region to region, several factors may explain this variation in the prevalence of the disease. The average infection rate for all regions is 32%. To prevent the spread of this disease in Algeria must be taken is mandatory and means of prevention into account.

  8. OPCIONES DE MANEJO SOSTENIBLE DEL SUELO EN ZONAS ARIDAS: APROVECHAMIENTO DE LA HALÓFITA Salicornia bigelovii (Torr. Y USO DE BIOFERTILIZANTES EN LA AGRICULTURA MODERNA

    Directory of Open Access Journals (Sweden)

    Edgar Omar Rueda Puente

    2010-12-01

    Full Text Available The study and development of plant resources in arid-saline environments is increasing. Salicornia bigelovii is a halophyte of great interest. However, the productivity of these plants is limited by nitrogen availability. An alternative to chemical fertilizers are the plant growth promoting bacteria and mycorrhizae. In the present study was evaluated the effect of Glomus intraradices, three strains of rhizobacteria (Klebsiella pneumoniae, Bacillus amyloliquefaciens and Azospirillum halopraeferens and two soil types (clayey and sandy on Salicornia under greenhouse conditions. The inoculation of bacteria under conditions of sandy soil significantly stimulated growth and nutritional factor of Salicornia (NPK. Synergism was observed between G. intraradices and rhizobacteria. When inoculated bacteria in individually form, behaved with significant differences. There was synergism between G. intraradices and Klebsiella pneumoniae and A. halopraeferens in the uptake of N, the opposite happened with G. intraradices and Bacillus amyloliquefaciens with high significant values in the absorption of P and K. The soil was a determining factor in behavior and expression of the benefit of the microorganisms. Rhizobacteria and mycorrhiza in the study have potential for use as growth promoters in salicornia.

  9. Inhibitory effect of indole analogs against Paenibacillus larvae, the causal agent of American foulbrood disease.

    Science.gov (United States)

    Alvarado, Israel; Margotta, Joseph W; Aoki, Mai M; Flores, Fernando; Agudelo, Fresia; Michel, Guillermo; Elekonich, Michelle M; Abel-Santos, Ernesto

    2017-09-01

    Paenibacillus larvae, a Gram-positive bacterium, causes American foulbrood (AFB) in honey bee larvae (Apis mellifera Linnaeus [Hymenoptera: Apidae]). P. larvae spores exit dormancy in the gut of bee larvae, the germinated cells proliferate, and ultimately bacteremia kills the host. Hence, spore germination is a required step for establishing AFB disease. We previously found that P. larvae spores germinate in response to l-tyrosine plus uric acid in vitro. Additionally, we determined that indole and phenol blocked spore germination. In this work, we evaluated the antagonistic effect of 35 indole and phenol analogs and identified strong inhibitors of P. larvae spore germination in vitro. We further tested the most promising candidate, 5-chloroindole, and found that it significantly reduced bacterial proliferation. Finally, feeding artificial worker jelly containing anti-germination compounds to AFB-exposed larvae significantly decreased AFB infection in laboratory-reared honey bee larvae. Together, these results suggest that inhibitors of P. larvae spore germination could provide another method to control AFB. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  10. Plant growth and resistance promoted by Streptomyces spp. in tomato.

    Science.gov (United States)

    Dias, Maila P; Bastos, Matheus S; Xavier, Vanessa B; Cassel, Eduardo; Astarita, Leandro V; Santarém, Eliane R

    2017-09-01

    Plant Growth Promoting Rhizobacteria (PGPR) represent an alternative to improve plant growth and yield as well as to act as agents of biocontrol. This study characterized isolates of Streptomyces spp. (Stm) as PGPR, determined the antagonism of these isolates against Pectobacterium carotovorum subsp. brasiliensis (Pcb), evaluated the ability of Stm on promoting growth and modulating the defense-related metabolism of tomato plants, and the potential of Stm isolates on reducing soft rot disease in this species. The VOC profile of Stm was also verified. Promotion of plant growth was assessed indirectly through VOC emission and by direct interaction with Stm isolates in the roots. Evaluation of soft rot disease was performed in vitro on plants treated with Stm and challenged with Pcb. Enzymes related to plant defense were then analyzed in plants treated with three selected isolates of Stm, and PM1 was chosen for further Pcb-challenging experiment. Streptomyces spp. isolates displayed characteristics of PGPR. PM3 was the isolate with efficient antagonism against Pcb by dual-culture. Most of the isolates promoted growth of root and shoot of tomato plants by VOC, and PM5 was the isolate that most promoted growth by direct interaction with Stm. Soft rot disease and mortality of plants were significantly reduced when plants were treated with StmPM1. Modulation of secondary metabolism was observed with Stm treatment, and fast response of polyphenoloxidases was detected in plants pretreated with StmPM1 and challenged with Pcb. Peroxidase was significantly activated three days after infection with Pcb in plants pretreated with StmPM1. Results suggest that Streptomyces sp. PM1 and PM5 have the potential to act as PGPR. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Assessment of Methylobacterium oryzae CBMB20 aggregates for salt tolerance and plant growth promoting characteristics for bio-inoculant development.

    Science.gov (United States)

    Chanratana, Mak; Han, Gwang Hyun; Roy Choudhury, Aritra; Sundaram, Seshadri; Halim, Md Abdul; Krishnamoorthy, Ramasamy; Kang, Yeongyeong; Sa, Tongmin

    2017-11-21

    Salinity is one of the major factors contributing to the loss of crop productivity and thereby impacting livelihood of people in more than 100 countries of the world and the area of land affected by salinity is increasing day by day. This will worsen due to various factors such as drought that might result in high soil salinity. Use of plant growth promoting rhizobacteria is one of the promising eco-friendly strategies for salinity stress management as part of sustainable agricultural practices. However, it requires selecting rhizobacteria with good survivability and adaptation to salt stress. In this study we report aggregation of Methylobacterium oryzae CBMB20 cells grown in media containing high C/N ratio (30:1) than in media containing low C/N ratio (7:1). Aggregated Methylobacterium oryzae CBMB20 cells exhibited enhanced tolerance to UV irradiation, heat, desiccation, different temperature regimes, oxidative stress, starvation and supported higher population in media. Poly-β-hydroxybutyrate accumulation, exopolysaccharide production, proline accumulation and biofilm formation were good at 100 mM salt concentration with good microbial cell hydrophobicity at both 50 and 100 mM than other concentrations. Both the aggregated and non-aggregated cells grown under 0-200 mM salt concentrations produced IAA even at 200 mM salt concentration with a peak at 100 mM concentration with aggregated cells producing significantly higher quantities. ACC deaminase activity was observed in all NaCl concentrations studied with gradual and drastic reduction in aggregated and non-aggregated cells over increased salt concentrations.

  12. Characterization and pulp refining activity of a Paenibacillus campinasensis cellulase expressed in Escherichia coli.

    Science.gov (United States)

    Ko, Chun-Han; Tsai, Chung-Hung; Lin, Po-Heng; Chang, Ko-Cheng; Tu, Jenn; Wang, Ya-Nang; Yang, Chien-Ying

    2010-10-01

    The Cel-BL11 gene from Paenibacillus campinasensis BL11 was cloned and expressed in Escherichia coli as a His-tag fusion protein. Zymographic analysis of the recombinant protein revealed cellulase activity corresponding to a protein with a 38-kDa molecular weight. The optimum temperature and pH for purified cellulase were 60 °C and pH 7.0, respectively. The enzyme retained more than 80% activity after 8h at 60 °C at pH 6 and 7. The cellulase has a Km of 11.25 mg/ml and a Vmax of 1250 μmol/min/mg with carboxylmethyl cellulose (CMC). Then enzyme was active on Avicel, swollen Avicel, CMC, barley β-glucan, laminarin in the presence of 100 mM acetate buffer. It was inhibited by Hg²⁺, Cu²⁺ and Zn²⁺. Significant kraft pulp refining energy saving, 10%, was exhibited by the pretreatment of this cellulase applied at 2 IU per gram of oven-dried pulp. Broad pH and temperature stability render this cellulase a convenient applicability toward current mainstream biomass conversion and other industrial processes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Inhibition of the growth of Ascosphaera apis by Bacillus and Paenibacillus strains isolated from honey Inhibición del crecimiento de Ascosphaera apis mediante cepas de Bacillus y Paenibacillus aisladas de miel

    Directory of Open Access Journals (Sweden)

    F. J. Reynaldi

    2004-03-01

    Full Text Available The fungus Ascosphaera apis, the causative agent of chalkbrood disease in honeybee larvae, occurs throughout the world and is found in many beekeeping areas of Argentina. The potential as biocontrol agents of 249 aerobic spore-forming bacterial antagonists isolated from honey samples was evaluated. Each isolate was screened against A. apis by a central disk test assay. Ten bacterial strains that showed the best antagonistic effect to A. apis were selected for further study and identified as Bacillus cereus (m363, mv86, mv81, mv75, Bacillus circulans (Fr231, m448b, Bacillus megaterium (m435, Bacillus pumilus (m354, Bacillus subtilis (m329, and Paenibacillus alvei (m321. For testing the efficiency of the selected strains, a paired culture test was used with 5 replicates of each combination bacterial antagonist / A. apis strain, and 5 replications for each control on 4 different culture media. The analysis of variance and posterior comparison of means according to LSD method showed that the best antagonists when using YGPSA medium were B. subtilis (m329 and B. megaterium (m435, and in the case of MYPGP medium the most efficient were B. circulans strains Fr 231 and m448b.La cría yesificada es una micosis invasiva ocasionada por el hongo heterotálico Ascosphaera apis que afecta exclusivamente a las larvas de las abejas. La enfermedad tiene difusión mundial y en la Argentina se halla diseminada en todas las áreas donde se realiza apicultura. Se estudió la potencialidad de 249 cepas de bacterias esporuladas aeróbicas aisladas de miel como agentes biocontroladores del hongo mediante un ensayo en disco central en condiciones de laboratorio. Se seleccionaron como mejores antagonistas 10 cepas bacterianas identificadas como Bacillus cereus (m363, mv86, mv81, mv75, Bacillus circulans (Fr231, m448b, Bacillus megaterium (m435, Bacillus pumilus (m354, Bacillus subtilis (m329, y Paenibacillus alvei (m321. Para probar la eficiencia de las cepas

  14. Halotolerant PGPRs Prevent Major Shifts in Indigenous Microbial Community Structure Under Salinity Stress.

    Science.gov (United States)

    Bharti, Nidhi; Barnawal, Deepti; Maji, Deepamala; Kalra, Alok

    2015-07-01

    The resilience of soil microbial populations and processes to environmental perturbation is of increasing interest as alteration in rhizosphere microbial community dynamics impacts the combined functions of plant-microbe interactions. The present study was conducted to investigate the effect of inoculation with halotolerant rhizobacteria Bacillus pumilus (STR2), Halomonas desiderata (STR8), and Exiguobacterium oxidotolerans (STR36) on the indigenous root-associated microbial (bacterial and fungal) communities in maize under non-saline and salinity stress. Plants inoculated with halotolerant rhizobacteria recorded improved growth as illustrated by significantly higher shoot and root dry weight and elongation in comparison to un-inoculated control plants under both non-saline and saline conditions. Additive main effect and multiplicative interaction ordination analysis revealed that plant growth promoting rhizobacteria (PGPR) inoculations as well as salinity are major drivers of microbial community shift in maize rhizosphere. Salinity negatively impacts microbial community as analysed through diversity indices; among the PGPR-inoculated plants, STR2-inoculated plants recorded higher values of diversity indices. As observed in the terminal-restriction fragment length polymorphism analysis, the inoculation of halotolerant rhizobacteria prevents major shift of the microbial community structure, thus enhancing the resilience capacity of the microbial communities.

  15. The S-layer homology domain-containing protein SlhA from Paenibacillus alvei CCM 2051(T) is important for swarming and biofilm formation.

    Science.gov (United States)

    Janesch, Bettina; Koerdt, Andrea; Messner, Paul; Schäffer, Christina

    2013-01-01

    Swarming and biofilm formation have been studied for a variety of bacteria. While this is well investigated for Gram-negative bacteria, less is known about Gram-positive bacteria, including Paenibacillus alvei, a secondary invader of diseased honeybee colonies infected with Melissococcus pluton, the causative agent of European foulbrood (EFB). Paenibacillus alvei CCM 2051(T) is a Gram-positive bacterium which was recently shown to employ S-layer homology (SLH) domains as cell wall targeting modules to display proteins on its cell surface. This study deals with the newly identified 1335-amino acid protein SlhA from P. alvei which carries at the C‑terminus three consecutive SLH-motifs containing the predicted binding sequences SRGE, VRQD, and LRGD instead of the common TRAE motif. Based on the proof of cell surface location of SlhA by fluorescence microscopy using a SlhA-GFP chimera, the binding mechanism was investigated in an in vitro assay. To unravel a putative function of the SlhA protein, a knockout mutant was constructed. Experimental data indicated that one SLH domain is sufficient for anchoring of SlhA to the cell surface, and the SLH domains of SlhA recognize both the peptidoglycan and the secondary cell wall polymer in vitro. This is in agreement with previous data from the S-layer protein SpaA, pinpointing a wider utilization of that mechanism for cell surface display of proteins in P. alvei. Compared to the wild-type bacterium ΔslhA revealed changed colony morphology, loss of swarming motility and impaired biofilm formation. The phenotype was similar to that of the flagella knockout Δhag, possibly due to reduced EPS production influencing the functionality of the flagella of ΔslhA. This study demonstrates the involvement of the SLH domain-containing protein SlhA in swarming and biofilm formation of P. alvei CCM 2051(T).

  16. The S-layer homology domain-containing protein SlhA from Paenibacillus alvei CCM 2051(T is important for swarming and biofilm formation.

    Directory of Open Access Journals (Sweden)

    Bettina Janesch

    Full Text Available Swarming and biofilm formation have been studied for a variety of bacteria. While this is well investigated for Gram-negative bacteria, less is known about Gram-positive bacteria, including Paenibacillus alvei, a secondary invader of diseased honeybee colonies infected with Melissococcus pluton, the causative agent of European foulbrood (EFB.Paenibacillus alvei CCM 2051(T is a Gram-positive bacterium which was recently shown to employ S-layer homology (SLH domains as cell wall targeting modules to display proteins on its cell surface. This study deals with the newly identified 1335-amino acid protein SlhA from P. alvei which carries at the C‑terminus three consecutive SLH-motifs containing the predicted binding sequences SRGE, VRQD, and LRGD instead of the common TRAE motif. Based on the proof of cell surface location of SlhA by fluorescence microscopy using a SlhA-GFP chimera, the binding mechanism was investigated in an in vitro assay. To unravel a putative function of the SlhA protein, a knockout mutant was constructed. Experimental data indicated that one SLH domain is sufficient for anchoring of SlhA to the cell surface, and the SLH domains of SlhA recognize both the peptidoglycan and the secondary cell wall polymer in vitro. This is in agreement with previous data from the S-layer protein SpaA, pinpointing a wider utilization of that mechanism for cell surface display of proteins in P. alvei. Compared to the wild-type bacterium ΔslhA revealed changed colony morphology, loss of swarming motility and impaired biofilm formation. The phenotype was similar to that of the flagella knockout Δhag, possibly due to reduced EPS production influencing the functionality of the flagella of ΔslhA.This study demonstrates the involvement of the SLH domain-containing protein SlhA in swarming and biofilm formation of P. alvei CCM 2051(T.

  17. Indole and 3-indolylacetonitrile inhibit spore maturation in Paenibacillus alvei

    Directory of Open Access Journals (Sweden)

    Cho Moo

    2011-05-01

    Full Text Available Abstract Background Bacteria use diverse signaling molecules to ensure the survival of the species in environmental niches. A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole that functions as an intercellular signal controlling diverse aspects of bacterial physiology. Results In this study, we sought a novel role of indole in a Gram-positive bacteria Paenibacillus alvei that can produce extracellular indole at a concentration of up to 300 μM in the stationary phase in Luria-Bertani medium. Unlike previous studies, our data show that the production of indole in P. alvei is strictly controlled by catabolite repression since the addition of glucose and glycerol completely turns off the indole production. The addition of exogenous indole markedly inhibits the heat resistance of P. alvei without affecting cell growth. Observation of cell morphology with electron microscopy shows that indole inhibits the development of spore coats and cortex in P. alvei. As a result of the immature spore formation of P. alvei, indole also decreases P. alvei survival when exposed to antibiotics, low pH, and ethanol. Additionally, indole derivatives also influence the heat resistance; for example, a plant auxin, 3-indolylacetonitrile dramatically (2900-fold decreased the heat resistance of P. alvei, while another auxin 3-indoleacetic acid had a less significant influence on the heat resistance of P. alvei. Conclusions Together, our results demonstrate that indole and plant auxin 3-indolylacetonitrile inhibit spore maturation of P. alvei and that 3-indolylacetonitrile presents an opportunity for the control of heat and antimicrobial resistant spores of Gram-positive bacteria.

  18. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 3. Plant Growth Promoting Rhizobacteria - Potential Microbes for Sustainable Agriculture. Jay Shankar Singh. General Article Volume 18 Issue 3 March 2013 pp 275-281 ...

  19. Plant growth promoting rhizobacteria: Beneficial effects for healthy ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-07-06

    Jul 6, 2016 ... lytic enzymes, hydrogen cyanide and volatile compounds. In view of the ..... atmospheric nitrogen into ammonia (N2 + 4H2 2NH3 +. H2) (Weyens et ...... Identification of ... Microbiological methods for assessing soil quality. ed.

  20. Biological Control of Apple Anthracnose by Paenibacillus polymyxa APEC128, an Antagonistic Rhizobacterium.

    Science.gov (United States)

    Kim, Young Soo; Balaraju, Kotnala; Jeon, Yongho

    2016-06-01

    The present study investigated the suppression of the disease development of anthracnose caused by Colletotrichum gloeosporioides and C. acutatum in harvested apples using an antagonistic rhizobacterium Paenibacillus polymyxa APEC128 (APEC128). Out of 30 bacterial isolates from apple rhizosphere screened for antagonistic activity, the most effective strain was APEC128 as inferred from the size of the inhibition zone. This strain showed a greater growth in brain-heart infusion (BHI) broth compared to other growth media. There was a reduction in anthracnose symptoms caused by the two fungal pathogens in harvested apples after their treatment with APEC128 in comparison with non-treated control. This effect is explained by the increased production of protease and amylase by APEC128, which might have inhibited mycelial growth. In apples treated with different APEC128 suspensions, the disease caused by C. gloeosporioides and C. acutatum was greatly suppressed (by 83.6% and 79%, respectively) in treatments with the concentration of 1 × 10(8) colony forming units (cfu)/ml compared to other lower dosages, suggesting that the suppression of anthracnose development on harvested apples is dose-dependent. These results indicated that APEC128 is one of the promising agents in the biocontrol of apple anthracnose, which might help to increase the shelf-life of apple fruit during the post-harvest period.

  1. Allelopathic principles for sustainable agriculture

    Science.gov (United States)

    Allelopathic research of the past few decades has established the feasibility of weed and plant disease management by allelopathic crop plants, plant residues, cultural manipulation, and microorganisms as bioherbicides and rhizobacteria. Inconsistency in the effectiveness of plant-growth-promoting ...

  2. Impact of arbuscular mycorrhizal fungus, Glomus intraradices ...

    African Journals Online (AJOL)

    Aghomotsegin

    leaves were maximum in P. Poae + G.I inoculated plants under water deficit condition. In the presence of ... Plant growth promoting rhizobacteria (PGPR) are usually in contact ... plant hormone indole-3-acetic acid (IAA) and the pathways of its ...

  3. Probiotic activities of Rhizobium laguerreae on growth and quality of spinach

    Czech Academy of Sciences Publication Activity Database

    Jimenez-Gomez, A.; Flores-Felix, J.D.; García-Fraile, Paula; Mateos, P.F.; Menéndez, E.; Velazquez, E.; Rivas, R.

    2018-01-01

    Roč. 8, JAN 10 (2018), č. článku 295. ISSN 2045-2322 Institutional support: RVO:61388971 Keywords : ZEA-MAYS L. * PROMOTING RHIZOBACTERIA * MEDITERRANEAN DIET Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.259, year: 2016

  4. Impact of heavy metals on the rhizosphere microflora of Jatropha ...

    African Journals Online (AJOL)

    The pot culture experiment of J. multifida dealt with the biochemical characteristics of heavy metals contaminated soil amended with waste water biosludge and biofertilizer (Azotobacter vinelandii). Plant growth promoting rhizobacteria such as Pseudomonas, Azotobacter and Rhizobium were isolated, characterized and ...

  5. Screening and Evaluation of the Bioremediation Potential of Cu/Zn-Resistant, Autochthonous Acinetobacter sp. FQ-44 from Sonchus oleraceus L.

    Science.gov (United States)

    Fang, Qing; Fan, Zhengqiu; Xie, Yujing; Wang, Xiangrong; Li, Kun; Liu, Yafeng

    2016-01-01

    The quest for new, promising and indigenous plant growth-promoting rhizobacteria and a deeper understanding of their relationship with plants are important considerations in the improvement of phytoremediation. This study focuses on the screening of plant beneficial Cu/Zn-resistant strains and assessment of their bioremediation potential (metal solubilization/tolerance/biosorption and effects on growth of Brassica napus seedlings) to identify suitable rhizobacteria and examine their roles in microbes-assisted phytoremediation. Sixty Cu/Zn-resistant rhizobacteria were initially isolated from Sonchus oleraceus grown at a multi-metal-polluted site in Shanghai, China. From these strains, 19 isolates that were all resistant to 300 mg⋅L -1 Cu as well as 300 mg⋅L -1 Zn, and could simultaneously grow on Dworkin-Foster salt minimal medium containing 1-aminocyclopropane-1-carboxylic acid were preliminarily selected. Of those 19 isolates, 10 isolates with superior plant growth-promoting properties (indole-3-acetic acid production, siderophore production, and insoluble phosphate solubilization) were secondly chosen and further evaluated to identify those with the highest bioremediation potential and capacity for bioaugmentation. Strain S44, identified as Acinetobacter sp. FQ-44 based on 16S rDNA sequencing, was specifically chosen as the most favorable strain owing to its strong capabilities to (1) promote the growth of rape seedlings (significantly increased root length, shoot length, and fresh weight by 92.60%, 31.00%, and 41.96%, respectively) under gnotobiotic conditions; (2) tolerate up to 1000 mg⋅L -1 Cu and 800 mg⋅L -1 Zn; (3) mobilize the highest concentrations of water-soluble Cu, Zn, Pb, and Fe (16.99, 0.98, 0.08, and 3.03 mg⋅L -1 , respectively); and (4) adsorb the greatest quantities of Cu and Zn (7.53 and 6.61 mg⋅g -1 dry cell, respectively). Our findings suggest that Acinetobacter sp. FQ-44 could be exploited for bacteria-assisted phytoextraction

  6. New Paenibacillus larvae bacterial isolates from honey bee colonies infected with American foulbrood disease in Egypt.

    Science.gov (United States)

    Masry, Saad Hamdy Daif; Kabeil, Sanaa Soliman; Hafez, Elsayed Elsayed

    2014-03-04

    The American foulbrood disease is widely distributed all over the world and causes a serious problem for the honeybee industry. Different infected larvae were collected from different apiaries, ground in phosphate saline buffer (PSB) and bacterial isolation was carried out on nutrient agar medium. Different colonies were observed and were characterized biologically. Two bacterial isolates (SH11 and SH33) were subjected to molecular identification using 16S rRNA gene and the sequence analysis revealed that the two isolates are Paenibacillus larvae with identity not exceeding 83%. The DNA sequence alignment between the other P. larvae bacterial strains and the two identified bacterial isolates showed that all the examined bacterial strains have the same ancestor, i.e. they have the same origin. The SH33 isolate was closely related to the P. larvae isolated from Germany, whereas the isolate SH11 was close to the P. larvae isolated from India. The phylogenetic tree constructed for 20 different Bacillus sp. and the two isolates SH11 and SH33 demonstrated that the two isolates are Bacillus sp. and they are new isolates. The bacterial isolates will be subjected to more tests for more confirmations.

  7. Sfp-type PPTase inactivation promotes bacterial biofilm formation and ability to enhance wheat drought tolerance

    Directory of Open Access Journals (Sweden)

    Salme eTimmusk

    2015-05-01

    Full Text Available Paenibacillus polymyxa is a common soil bacterium with broad range of practical applications. An important group of secondary metabolites in P. polymyxa are nonribosomal peptide and polyketide derived metabolites (NRP/PK. Modular nonribosomal peptide synthetases catalyse main steps in the biosynthesis of the complex secondary metabolites. Here we report on the inactivation of an A26 sfp-type phosphopantetheinyl transferase. The inactivation of the gene resulted in loss of NRP/PK production. In contrast to the former Bacillus spp. model the mutant strain compared to wild type showed greatly enhanced biofilm formation ability. Its biofilm promotion is directly mediated by NRP/PK, as exogenous addition of the wild type metabolite extracts restores its biofilm formation level. Wheat inoculation with bacteria that had lost their sfp-type PPTase gene resulted in two times higher plant survival and about three times increased biomass under severe drought stress compared to wild type.

  8. Role of bacterial biofertilizers in agriculture and forestry

    Czech Academy of Sciences Publication Activity Database

    García-Fraile, Paula; Menendéz, E.; Rivas, R.

    2015-01-01

    Roč. 2, č. 3 (2015), s. 183-205 ISSN 2306-5354 R&D Projects: GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : plant growth-promoting Rhizobacteria * sustainable agriculture * biofertilizer s Subject RIV: EE - Microbiology, Virology

  9. Phenazine-1-carboxylic acid influences biofilm development and turnover of rhizobacterial biomass in a soil moisture-dependent manner

    Science.gov (United States)

    Rhizobacterial biofilm development influences terrestrial carbon and nitrogen cycles with ramifications for crop and soil health. Phenazine-1-carboxylic acid (PCA) is a redox-active metabolite produced by rhizobacteria in dryland wheat fields of Washington and Oregon, USA. PCA promotes biofilm dev...

  10. Characterization of 1-Aminocyclopropane-1-Carboxylate (ACC) Deaminase-Containing Pseudomonas spp. in the Rhizosphere of Salt-Stressed Canola

    NARCIS (Netherlands)

    Akhgar, A.; Arzanlou, M.; Bakker, Peter; Hamidpour, M.

    2014-01-01

    When exposed to biotic or abiotic stress conditions, plants produce ethylene from its immediate precursor 1-aminocyclopropane-1- carboxylate (ACC), leading to retarded root growth and senescence. Many plant growth-promoting rhizobacteria contain the enzyme ACC deaminase and this enzyme can cleave

  11. Influence of integrated phosphorus supply and plant growth ...

    African Journals Online (AJOL)

    To guarantee a sufficient phosphorus supply for plants, a rapid and permanent mobilization of phosphorus from the labile phosphorus fractions is necessary, because phosphorus concentrations in soil solution are generally low. Several plant growth-promoting rhizobacteria (PGPR) have shown potential to enhance ...

  12. Beneficial microbes in a changing environment: are they always helping plants to deal with insects?

    NARCIS (Netherlands)

    Pineda, A.; Dicke, M.; Pieterse, C.M.J.; Pozo, M.J.

    2013-01-01

    Plants have a complex immune system that defends them against attackers (e.g. herbivores and microbial pathogens) but that also regulates the interactions with mutualistic organisms (e.g. mycorrhizal fungi and plant growth-promoting rhizobacteria). Plants have to respond to multiple environmental

  13. Shelf life study on Nuclear Malaysia biofertilizer products

    International Nuclear Information System (INIS)

    Phua Choo Kwai Hoe; Ahmad Nazrul Abd Wahid; Khairuddin Abdul Rahim

    2009-01-01

    Phosphate solubilising bacteria and plant growth promoting rhizobacteria are biofertilizer microorganisms known to increase crop yields. It is important to prepare suitable sterile carriers or substrates for these microorganisms into biofertilizer products with long shelf life. Optimum storage conditions, especially storage temperature is needed to improve shelf life of the products. Isolates of two phosphate solubilising bacteria (AP1 and AP3) and one plant growth promoting rhizobacteria (AP2) have been developed into biofertilizer products in Malaysian Nuclear Agency (NuclearMalaysia). These isolates were inoculated into a compost-based carrier, sterilised by gamma irradiation at 50 kGy, from MINTec-SINAGAMA, Nuclear Malaysia. Biofertilizer products kept at low temperatures (9 ± 2 degree C) showed better shelf life (storage for six months) as compared to those stored at room temperatures (28 ± 2 degree C). Further observation of the shelf life is still in progress. (Author)

  14. Lead application for the stimulation of fusaricidin type compounds by paenibacillus polymyxa SQR-21

    International Nuclear Information System (INIS)

    Raza, W.; Wu, H.; Qirong, S.

    2011-01-01

    Paenibacillus polymyxa strains produce fusaricidin type compounds that are active against a wide variety of Gram-positive bacteria and fungi. Growth and production of fusaricidin type antifungal compounds by P. polymyxa SQR-21 were compared in tryptone broth supplemented with three concentrations (200, 400 and 600 mu M) of lead. The data revealed that the growth of P. polymyxa increased by 7-34 % and fusaricidin type compounds production increased by 15-70 % with the increase in concentration of lead ion (Pb/sup 2+/). The increase in Pb/sup 2+/ concentration, decreased the intracellular carbohydrate contents but increased the intracellular protein and lipid contents, however, higher levels of Pb/sup 2+/ inhibited the intracellular protein and lipid contents. On the other hand, extracellular protein contents were decreased and extracellular polysaccharide contents were increased with the increase in Pb/sup 2+/ contents in liquid culture. In addition, the regulatory effects of lead were also reflected by decrease of total RNA and increase of relative expression of the six module-containing non ribosomal peptide synthetase (FusA) when the lead treated experimental samples were compared with the untreated controls. The Pb/sup 2+/ seems to be directly or indirectly correlated with the production of fusaricidin type antifungal compounds. This information will aid in developing fermentation technology for maximum antibiotic production. (author)

  15. Responses of three grass species to creosote during phytoremediation

    International Nuclear Information System (INIS)

    Huang Xiaodong; El-Alawi, Yousef; Penrose, Donna M.; Glick, Bernard R.; Greenberg, Bruce M.

    2004-01-01

    Phytoremediation of creosote-contaminated soil was monitored in the presence of Tall fescue, Kentucky blue grass, or Wild rye. For all three grass species, plant growth promoting rhizobacteria (PGPR) were evaluated for plant growth promotion and protection of plants from contaminant toxicity. A number of parameters were monitored including plant tissue water content, root growth, plant chlorophyll content and the chlorophyll a/b ratio. The observed physiological data indicate that some plants mitigated the toxic effects of contaminants. In addition, in agreement with our previous experiments reported in the accompanying paper (Huang, X.-D., El-Alawi, Y., Penrose, D.M., Glick, B.R., Greenberg, B.M., 2004. A multi-process phytoremediation system for removal of polycyclic aromatic hydrocarbons from contaminated soil. Environ. Poll. doi: 10.1016/j.envpol.2003.09.031), PGPR were able to greatly enhance phytoremediation. PGPR accelerated plant growth, especially roots, in heavily contaminated soils, diminishing the toxic effects of contaminants to plants. Thus, the increased root biomass in PGPR-treated plants led to more effective remediation. - Plant growth promoting rhizobacteria enhanced growth and remediation of three grass species

  16. Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences

    NARCIS (Netherlands)

    Kurm, Viola; van der Putten, W.H.; Pineda, A.M.; Hol, W.H.G.

    2018-01-01

    • Background and Aims Plant growth-promoting rhizobacteria (PGPR) strains can influence plant–insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence

  17. Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences

    NARCIS (Netherlands)

    Kurm, Viola; Putten, Van Der Wim H.; Pineda, Ana; Hol, G.W.H.

    2018-01-01

    • Background and Aims: Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence

  18. Production of R,R-2,3-butanediol of ultra-high optical purity from Paenibacillus polymyxa ZJ-9 using homologous recombination.

    Science.gov (United States)

    Zhang, Li; Cao, Can; Jiang, Ruifan; Xu, Hong; Xue, Feng; Huang, Weiwei; Ni, Hao; Gao, Jian

    2018-08-01

    The present study describes the use of metabolic engineering to achieve the production of R,R-2,3-butanediol (R,R-2,3-BD) of ultra-high optical purity (>99.99%). To this end, the diacetyl reductase (DAR) gene (dud A) of Paenibacillus polymyxa ZJ-9 was knocked out via homologous recombination between the genome and the previously constructed targeting vector pRN5101-L'C in a process based on homologous single-crossover. PCR verification confirmed the successful isolation of the dud A gene disruption mutant P. polymyxa ZJ-9-△dud A. Moreover, fermentation results indicated that the optical purity of R,R-2,3-BD increased from about 98% to over 99.99%, with a titer of 21.62 g/L in Erlenmeyer flasks. The latter was further increased to 25.88 g/L by fed-batch fermentation in a 5-L bioreactor. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Root treatment with rhizobacteria antagonistic to Phytophthora blight affects anthracnose occurrence, ripening, and yield of pepper fruit in the plastic house and field.

    Science.gov (United States)

    Sang, Mee Kyung; Kim, Jeong Do; Kim, Beom Seok; Kim, Ki Deok

    2011-06-01

    We previously selected rhizobacterial strains CCR04, CCR80, GSE09, ISE13, and ISE14, which were antagonistic to Phytophthora blight of pepper. In this study, we investigated the effects of root treatment of rhizobacteria on anthracnose occurrence, ripening, and yield of pepper fruit in the plastic house and field in 2008 and 2009. We also examined the effects of volatiles produced by the strains on fruit ripening and on mycelial growth and spore development of Colletotrichum acutatum and Phytophthora capsici in the laboratory, identifying the volatile compounds by gas chromatography-mass spectrometry (GC-MS). In the house tests, all strains significantly (P anthracnose incidence on pepper fruit; strains GSE09 and ISE14 consistently produced higher numbers of pepper fruit or increased the fresh weight of red fruit more than the controls in both years. In the field tests, all strains significantly (P anthracnose occurrence on either green or red pepper fruit; strain ISE14 consistently produced higher numbers or increased fresh weights of red fruit more than the controls in both years. In the laboratory tests, volatiles produced by strains GSE09 and ISE13 only stimulated maturation of pepper fruit from green (unripe) to red (ripe) fruit; the volatiles of certain strains inhibited the growth and development of C. acutatum and P. capsici. On the other hand, GC-MS analysis of volatiles of strains GSE09 and ISE13 revealed 17 distinct compounds in both strains, including decane, dodecane, 1,3-di-tert-butylbenzene, tetradecane, 2,4-di-tert-butylphenol, and hexadecane. Among these compounds, 2,4-di-tert-butylphenol only stimulated fruit ripening and inhibited growth and development of the pathogens. Taken together, strains GSE09 and ISE14 effectively reduced anthracnose occurrence and stimulated pepper fruit ripening and yield, possibly via bacterial volatiles. Therefore, these two strains could be potential agents for controlling Phytophthora blight and anthracnose, and for

  20. Biochemical characterization of a novel β-galactosidase from Paenibacillus barengoltzii suitable for lactose hydrolysis and galactooligosaccharides synthesis.

    Science.gov (United States)

    Liu, Yu; Chen, Zhou; Jiang, Zhengqiang; Yan, Qiaojuan; Yang, Shaoqing

    2017-11-01

    A β-galactosidase gene (PbBGal2A) was cloned from Paenibacillus barengoltzii and expressed in Escherichia coli. The in silico analysis of the deduced amino acid sequences revealed that PbBGal2A shared the highest identity of 40% with the characterized glycoside hydrolase (GH) family 2 β-galactosidase from Actinobacillus pleuropneumoniae. The recombinant β-galactosidase (PbBGal2A) was purified with a molecular mass of 124.2kDa on SDS-PAGE. The optimal pH and temperature of PbBGal2A were determined to be pH 7.5 and 45°C, respectively. PbBGal2A was stable within pH 6.0-8.0 and up to 45°C. It completely hydrolyzed the lactose in milk and whey powder solution. In addition, PbBGal2A exhibited high transglycosylation activity and a maximum yield of 47.9% (w/w) for galactooligosaccharides (GOS) production was obtained in 8h at a lactose concentration of 350g/L. These properties make PbBGal2A an ideal candidate for commercial use in the production of lactose-free milk and GOS. Copyright © 2017. Published by Elsevier B.V.

  1. Klebsiella oxytoca '10mkr7\\' stimulates Striga suicidal germination in ...

    African Journals Online (AJOL)

    The Striga species are obligate root parasitic plants. Plant growth promoting rhizobacteria could enhance Striga suicidal germination. In screen-house studies we quantified the effect of bacterial inoculation with increasing maize plant density on the parasitic weed Striga hermonthica. The design used was a randomized ...

  2. Plant exudates promote PCB degradation by a rhodococcal rhizobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Toussaint, Jean-Patrick; Pham, Thi Thanh My; Barriault, Diane; Sylvestre, Michel [Instiut National de la Recherche Scientifique INRS, Laval, QC (Canada). Inst. Armand-Frappier

    2012-09-15

    Rhodococcus erythropolis U23A is a polychlorinated biphenyl (PCB)-degrading bacterium isolated from the rhizosphere of plants grown on a PCB-contaminated soil. Strain U23A bphA exhibited 99% identity with bphA1 of Rhodococcus globerulus P6. We grew Arabidopsis thaliana in a hydroponic axenic system, collected, and concentrated the plant secondary metabolite-containing root exudates. Strain U23A exhibited a chemotactic response toward these root exudates. In a root colonizing assay, the number of cells of strain U23A associated to the plant roots (5.7 x 105 CFU g{sup -1}) was greater than the number remaining in the surrounding sand (4.5 x 104 CFU g{sup -1}). Furthermore, the exudates could support the growth of strain U23A. In a resting cell suspension assay, cells grown in a minimal medium containing Arabidopsis root exudates as sole growth substrate were able to metabolize 2,3,4'- and 2,3',4-trichlorobiphenyl. However, no significant degradation of any of congeners was observed for control cells grown on Luria-Bertani medium. Although strain U23A was unable to grow on any of the flavonoids identified in root exudates, biphenyl-induced cells metabolized flavanone, one of the major root exudate components. In addition, when used as co-substrate with sodium acetate, flavanone was as efficient as biphenyl to induce the biphenyl catabolic pathway of strain U23A. Together, these data provide supporting evidence that some rhodococci can live in soil in close association with plant roots and that root exudates can support their growth and trigger their PCB-degrading ability. This suggests that, like the flagellated Gram-negative bacteria, non-flagellated rhodococci may also play a key role in the degradation of persistent pollutants. (orig.)

  3. Interactive optimization of biosurfactant production by Paenibacillus alvei ARN63 isolated from an Iranian oil well.

    Science.gov (United States)

    Najafi, A R; Rahimpour, M R; Jahanmiri, A H; Roostaazad, R; Arabian, D; Soleimani, M; Jamshidnejad, Z

    2011-01-01

    The potential of an indigenous bacterial strain isolated from an Iranian oil field for the production of biosurfactant was investigated in this study. After isolation, the bacterium was characterized to be Paenibacillus alvei by biochemical tests and 16S ribotyping. The biosurfactant, which was produced by this bacterium, was able to lower the surface tension of media to 35 mN/m. Accordingly, thin layer chromatography (TLC) and FT-IR has been carried out to determine compositional analysis of the produced biosurfactant. After all the tests related to characterization of the biosurfactant produced by the isolated bacterium, it was characterized as lipopeptide derivative. The combination of central composite rotatable design (CCRD) and response surface methodology (RSM) was exploited to optimize biosurfactant production. Therefore, variations of four impressive parameters, pH, temperature, glucose and salinity concentrations were selected for optimization of growth conditions. The empirical model developed through RSM in terms of effective operational factors mentioned above was found to be adequate to describe the biosurfactant production. A maximum reduction in surface tension was obtained under the optimal conditions of 13.03 g/l glucose concentration, 34.76 °C, 51.39 g/l total salt concentration and medium pH 6.89. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Inhibitory activity of Paenibacillus polymyxa on the biofilm formation of Cronobacter spp. on stainless steel surfaces.

    Science.gov (United States)

    Yang, Soonwook; Kim, Seonhwa; Ryu, Jee-Hoon; Kim, Hoikyung

    2013-07-01

    The objective of this study was to control the survival or biofilm formation of Cronobacter spp. on stainless steel surfaces using Paenibacillus polymyxa. The antibacterial activity of a cell-free culture supernatant (CFCS) of P. polymyxa against Cronobacter spp. was found to vary with P. polymyxa incubation time. Maximum activity occurred when P. polymyxa was incubated at 25 or 30 °C for 96 h. When the CFCS was introduced to Cronobacter spp. adhered to stainless steel strips at 25 °C for up to 72 h, the CFCS successfully inhibited Cronobacter biofilm formation. Additionally, stainless steel surfaces with a preformed P. polymyxa biofilm were exposed to Cronobacter spp. suspensions in PBS or 0.1% peptone water at 3, 5, or 7 log CFU/mL to facilitate its attachment. The Cronobacter population significantly decreased on this surface, regardless of inoculum level or carrier, when the P. polymyxa biofilm was present. However, the microbial population decreased within 6 h and remained unchanged thereafter when the surface was immersed in an inoculum suspended in 0.1% peptone water at 5 or 7 log CFU/mL. These results indicate that P. polymyxa is able to use a promising candidate competitive-exclusion microorganism to control Cronobacter spp. © 2013 Institute of Food Technologists®

  5. Plant growth promotion properties of bacterial strains isolated from the rhizosphere of the Jerusalem artichoke (Helianthus tuberosus L.) adapted to saline-alkaline soils and their effect on wheat growth.

    Science.gov (United States)

    Liu, Xiaolin; Li, Xiangyue; Li, Yan; Li, Runzhi; Xie, Zhihong

    2017-03-01

    The Jerusalem artichoke (JA; Helianthus tuberosus), known to be tolerant to saline-alkaline soil conditions, has been cultivated for many years in the Yellow River delta, Shandong Province coastal zone, in China. The aim of our study was to isolate nitrogen-fixing bacteria colonizing the rhizosphere of JA and to characterize other plant growth promotion properties. The ultimate goal was to identify isolates that could be used as inoculants benefiting an economic crop, in particular for improving wheat growth production in the Yellow River delta. Bacterial strains were isolated from the rhizosphere soil of JA on the basis of growth on nitrogen-free Ashby medium. Identification and phylogenetic analysis was performed after nucleotide sequencing of 16S rRNA gene. Plant-growth-promoting traits, such as nitrogen fixation activity, phosphate solubilization activity, indole-3-acetic acid production, were determined using conventional methods. Eleven strains were isolated and 6 of them were further examined for their level of salt tolerance and their effect on plant growth promotion. Inoculation of Enterobacter sp. strain N10 on JA and wheat led to significant increases in both root and shoot dry mass and shoot height. Enterobacter sp. strain N10 appeared to be the best plant-growth-promoting rhizobacteria to increase wheat productivity in future field applications.

  6. Antagonism of Two Plant-Growth Promoting Bacillus velezensis Isolates Against Ralstonia solanacearum and Fusarium oxysporum.

    Science.gov (United States)

    Cao, Yu; Pi, Hualiang; Chandrangsu, Pete; Li, Yongtao; Wang, Yuqi; Zhou, Han; Xiong, Hanqin; Helmann, John D; Cai, Yanfei

    2018-03-12

    Plant growth promoting rhizobacteria (PGPR) provide an effective and environmentally sustainable method to protect crops against pathogens. The spore-forming Bacilli are attractive PGPR due to their ease of storage and application. Here, we characterized two rhizosphere-associated Bacillus velezensis isolates (Y6 and F7) that possess strong antagonistic activity against Ralstonia solanacearum and Fusarium oxysporum under both laboratory and greenhouse conditions. We identified three lipopeptide (LP) compounds (surfactin, iturin and fengycin) as responsible for the antimicrobial activity of these two strains. We further dissected the contribution of LPs to various biological processes important for rhizosphere colonization. Although either iturin or fengycin is sufficient for antibacterial activity, cell motility and biofilm formation, only iturin plays a primary role in defense against the fungal pathogen F. oxysporum. Additionally, we found that LP production is significantly stimulated during interaction with R. solanacearum. These results demonstrate the different roles of LPs in the biology of B. velezensis and highlight the potential of these two isolates as biocontrol agents against phytopathogens.

  7. A novel interaction between plant-beneficial rhizobacteria and roots: colonization induces corn resistance against the root herbivore Diabrotica speciosa.

    Science.gov (United States)

    Santos, Franciele; Peñaflor, Maria Fernanda G V; Paré, Paul W; Sanches, Patrícia A; Kamiya, Aline C; Tonelli, Mateus; Nardi, Cristiane; Bento, José Mauricio S

    2014-01-01

    A number of soil-borne microorganisms, such as mycorrhizal fungi and rhizobacteria, establish mutualistic interactions with plants, which can indirectly affect other organisms. Knowledge of the plant-mediated effects of mutualistic microorganisms is limited to aboveground insects, whereas there is little understanding of what role beneficial soil bacteria may play in plant defense against root herbivory. Here, we establish that colonization by the beneficial rhizobacterium Azospirillum brasilense affects the host selection and performance of the insect Diabrotica speciosa. Root larvae preferentially orient toward the roots of non-inoculated plants versus inoculated roots and gain less weight when feeding on inoculated plants. As inoculation by A. brasilense induces higher emissions of (E)-β-caryophyllene compared with non-inoculated plants, it is plausible that the non-preference of D. speciosa for inoculated plants is related to this sesquiterpene, which is well known to mediate belowground insect-plant interactions. To the best of our knowledge, this is the first study showing that a beneficial rhizobacterium inoculant indirectly alters belowground plant-insect interactions. The role of A. brasilense as part of an integrative pest management (IPM) program for the protection of corn against the South American corn rootworm, D. speciosa, is considered.

  8. Production of Ginsenoside F2 by Using Lactococcus lactis with Enhanced Expression of β-Glucosidase Gene from Paenibacillus mucilaginosus.

    Science.gov (United States)

    Li, Ling; Shin, So-Yeon; Lee, Soo Jin; Moon, Jin Seok; Im, Wan Taek; Han, Nam Soo

    2016-03-30

    This study aimed to produce a pharmacologically active minor ginsenoside F2 from the major ginsenosides Rb1 and Rd by using a recombinant Lactococcus lactis strain expressing a heterologous β-glucosidase gene. The nucleotide sequence of the gene (BglPm) was derived from Paenibacillus mucilaginosus and synthesized after codon optimization, and the two genes (unoptimized and optimized) were expressed in L. lactis NZ9000. Codon optimization resulted in reduction of unfavorable codons by 50% and a considerable increase in the expression levels (total activities) of β-glucosidases (0.002 unit/mL, unoptimized; 0.022 unit/mL, optimized). The molecular weight of the enzyme was 52 kDa, and the purified forms of the enzymes could successfully convert Rb1 and Rd into F2. The permeabilized L. lactis expressing BglPm resulted in a high conversion yield (74%) of F2 from the ginseng extract. Utilization of this microbial cell to produce F2 may provide an alternative method to increase the health benefits of Panax ginseng.

  9. Characterization of plant growth-promoting traits of free-living diazotrophic bacteria and their inoculation effects on growth and nitrogen uptake of crop plants.

    Science.gov (United States)

    Islam, Md Rashedul; Madhaiyan, M; Deka Boruah, Hari P; Yim, Woojong; Lee, Gillseung; Saravanan, V S; Fu, Qingling; Hu, Hongqing; Sa, Tongmin

    2009-10-01

    The search for diverse plant growth-promoting (PGP) diazotrophic bacteria is gaining momentum as efforts are made to exploit them as biofertilizers for various economically important crops. In the present study, 17 diazotrophic strains belonging to eight different genera isolated from rice paddy fields were screened for multiple PGP traits and evaluated for their inoculation effects on canola and rice plants. All of the strains tested positive for 1- aminocyclopropane-1-carboxylate (ACC) deaminase activity and production of indole 3-acetic acid (IAA) and ammonia (NH3). Additionally, four of the strains were able to solubilize phosphorus (P), five tested positive for zinc (Zn) solubilization and sulfur (S) oxidation, and eight strains produced siderophores. Based on the presence of multiple PGP traits, 10 strains were selected for inoculation studies. Treatment with Herbaspirillum sp. RFNB26 resulted in maximum root length (54.3%), seedling vigor, and dry biomass in canola, whereas Paenibacillus sp. RFNB4 exhibited the lowest activity under gnotobiotic conditions. However, under pot culture conditions, Paenibacillus sp. RFNB4 significantly increased plant height and dry biomass production by 42.3% and 29.5%, respectively. Canola plants and rhizosphere soils inoculated with Bacillus sp. RFNB6 exhibited significantly higher nitrogenase activity. In greenhouse experiments, Serratia sp. RFNB18 increased rice plant height by 35.1%, Xanthomonas sp. RFNB24 enhanced biomass production by 84.6%, and rice rhizosphere soils inoculated with Herbaspirillum sp. RFNB26 exhibited the highest nitrogenase activity. Our findings indicate that most of the selected strains possess multiple PGP properties that significantly improve the growth parameters of the two plants when tested under controlled conditions.

  10. Novel multifunctional plant growth-promoting bacteria in co-compost of palm oil industry waste.

    Science.gov (United States)

    Chin, Clament Fui Seung; Furuya, Yoshihide; Zainudin, Mohd Huzairi Mohd; Ramli, Norhayati; Hassan, Mohd Ali; Tashiro, Yukihiro; Sakai, Kenji

    2017-11-01

    Previously, a unique co-compost produced by composting empty fruit bunch with anaerobic sludge from palm oil mill effluent, which contributed to establishing a zero-emission industry in Malaysia. Little was known about the bacterial functions during the composting process and fertilization capacity of this co-compost. We isolated 100 strains from the co-compost on 7 types of enumeration media and screened 25 strains using in vitro tests for 12 traits, grouping them according to three functions: plant growth promoting (fixation of nitrogen; solubilization of phosphorus, potassium, and silicate; production of 3-indoleacetic acid, ammonia, and siderophore), biocontrolling (production of chitinase and anti-Ganoderma activity), and composting (degradation of lignin, xylan, and cellulose). Using 16S rRNA gene sequence analysis, 25 strains with strong or multi-functional traits were found belong to the genera Bacillus, Paenibacillus, Citrobacter, Enterobacter, and Kosakonia. Furthermore, several strains of Citrobacter sedlakii exhibited a plant growth-stimulation in vivo komatsuna plant cultivation test. In addition, we isolated several multifunctional strains; Bacillus tequilensis CE4 (biocontrolling and composting), Enterobacter cloacae subsp. dissolvens B3 (plant growth promoting and biocontrolling), and C. sedlakii CESi7 (plant growth promoting and composting). Some bacteria in the co-compost play significant roles during the composting process and plant cultivation after fertilization, and some multifunctional strains have potential for use in accelerating the biodegradation of lignocellulosic biomass, protecting against Ganoderma boninense infection, and increasing the yield of palm oil. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Influence of PGPR Bacteria and Arbuscular Mycorrhizal Fungi on Growth and some Physiological Parameters of Onopordon acanthium in a Cd-Contaminated Soil

    Directory of Open Access Journals (Sweden)

    MirHassan Rasouli-Sadaghiani

    2017-02-01

    Full Text Available Introduction: Heavy metals (HMs are serious threat for environment due to their dangerous effects. These metals as contaminants that can be accumulated in soil and after absorption by plants, finally will be found in food chains. Cadmium (Cd is one of the dangerous HMs that threats the health of plants, living organisms and human. Physicochemical remediation methods may cause large changes in different characteristics of soils . Recently environmental-friendly strategies including phytoremediation have been emphasized by researchers. Phytoremediation that refers to the use of plants and their assistance with microorganisms for remediation of contaminated soils is an effective and low cost method for reclamation of heavy metals polluted soils. The most important limitation of phytoremediation is low availability of heavy metals and sensitivity of plants to contamination. There are evidences that soil microbes can help to overcome these limitations through several ways. Plant growth promoting rhizobacteria (PGPR and arbuscular mycorrhizal fungi (AMF are known to enhance plant growth and survival in heavy metal contaminated soils through different mechanisms including producing promoting metabolites, auxin, siderophore and antibiotics. In this study the role of some strains of PGPR (a mixture of Pseudomonas species including P. putida, P. fluorescens, and P. aeruginosa and AMF (a mixture of Glomus species including G. intraradices, G. mosseae and G. fasciculatum, on uptake and accumulation of Cd, Fe, Zn and Cu as well as some physiological properties of Onopordon (Onopordon acanthium L were evaluated. Materials and Methods:This study was carried out under greenhouse condition as a factorial experiment based on a randomized complete block design with two factors including Cd concentration (four levels and microbial treatment (three levels in three replications. Consequently, a soil was selected and spiked uniformly with different concentrations of

  12. Determinants of Plant Growth-promoting Ochrobactrum lupini KUDC1013 Involved in Induction of Systemic Resistance against Pectobacterium carotovorum subsp. carotovorum in Tobacco Leaves

    Directory of Open Access Journals (Sweden)

    Marilyn Sumayo

    2013-06-01

    Full Text Available The plant growth-promoting rhizobacterium Ochrobactrum lupini KUDC1013 elicited induced systemic resistance (ISR in tobacco against soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum. We investigated of its factors involved in ISR elicitation. To characterize the ISR determinants, KUDC1013 cell suspension, heat-treated cells, supernatant from a culture medium, crude bacterial lipopolysaccharide (LPS and flagella were tested for their ISR activities. Both LPS and flagella from KUDC1013 were effective in ISR elicitation. Crude cell free supernatant elicited ISR and factors with the highest ISR activity were retained in the n-butanol fraction. Analysis of the ISR-active fraction revealed the metabolites, phenylacetic acid (PAA, 1-hexadecene and linoleic acid (LA, as elicitors of ISR. Treatment of tobacco with these compounds significantly decreased the soft rot disease symptoms. This is the first report on the ISR determinants by plant growth-promoting rhizobacteria (PGPR KUDC1013 and identifying PAA, 1-hexadecene and LA as ISR-related compounds. This study shows that KUDC1013 has a great potential as biological control agent because of its multiple factors involved in induction of systemic resistance against phytopathogens.

  13. Screening and Evaluation of the Bioremediation Potential of Cu/Zn-resistant, Autochthonous Acinetobacter sp. FQ-44 from Sonchus oleraceus L.

    Directory of Open Access Journals (Sweden)

    Qing Fang

    2016-09-01

    Full Text Available The quest for new, promising and indigenous plant growth-promoting rhizobacteria and a deeper understanding of their relationship with plants are important considerations in the improvement of phytoremediation. This study focuses on the screening of plant beneficial Cu/Zn-resistant strains and assessment of their bioremediation potential (metal solubilization/tolerance/biosorption and effects on growth of Brassica napus seedlings to identify suitable rhizobacteria and examine their roles in microbes-assisted phytoremediation. Sixty Cu/Zn-resistant rhizobacteria were initially isolated from Sonchus oleraceus grown at a multi-metal-polluted site in Shanghai, China. From these strains, 19 isolates that were all resistant to 300 mg·L-1 Cu as well as 300 mg·L-1 Zn, and could simultaneously grow on Dworkin-Foster salt minimal medium containing 1-aminocyclopropane-1-carboxylic acid were preliminarily selected. Of those 19 isolates, 10 isolates with superior plant growth-promoting properties (indole-3-acetic acid production, siderophore production and insoluble phosphate solubilization were secondly chosen and further evaluated to identify those with the highest bioremediation potential and capacity for bioaugmentation. Strain S44, identified as Acinetobacter sp. FQ-44 based on 16S rDNA sequencing, was specifically chosen as the most favorable strain owing to its strong capabilities to (1 promote the growth of rape seedlings (significantly increased root length, shoot length and fresh weight by 92.60%, 31.00% and 41.96%, respectively under gnotobiotic conditions; (2 tolerate up to 1000 mg·L-1 Cu and 800 mg·L-1 Zn; (3 mobilize the highest concentrations of water-soluble Cu, Zn, Pb and Fe (16.99, 0.98, 0.08 and 3.03 mg·L-1, respectively; and (4 adsorb the greatest quantities of Cu and Zn (7.53 and 6.61 mg·g-1 dry cell, respectively. Our findings suggest that Acinetobacter sp. FQ-44 could be exploited for bacteria-assisted phytoextraction. Moreover

  14. Assessment of multi-strain PGPRs biofertilization as compared to ...

    African Journals Online (AJOL)

    Sids 1, grown in clayey soil to inoculation with plant-growth promoting rhizobacteria (PGPRs) such as cyanobacteria spp; Serratia sp; Rhizobium leguminosarum bv. viciae and Bacillus polymyxa either solely or in combinations in comparison to mineral N-fertilization, Full N-dose; 75 Kg N/fed. Results revealed the superiority ...

  15. The effect of plant growth promoting rhizobacteria (PGPR on quantitative and qualitative characteristics of Sesamum indicum L. with application of cover crops of Lathyrus sp. and Persian clover (Trifolium resopinatum L.

    Directory of Open Access Journals (Sweden)

    M. Jahan

    2016-05-01

    Full Text Available Cover crops cultivation and application of plant growth rhizobacteria are the key factors to enhance agroecosystem health. A field experiment was conducted at the Research Farm of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2009-2010. A split plot arrangement based on a complete randomized block design with three replications was used. Cultivation and no cultivation of Lathyrus sp. and Persian clover (Trifolium resopinatum in autumn assigned to the main plots. The sub plot factor consisted of three different types of biofertilizers plus control, including 1-nitroxin (containing of Azotobacter sp. and Azospirillum sp., 2- phosphate solubilizing bacteria (PSB (containing of Bacillus sp. and Pseudomonas sp., 3- biosulfur (containing of Thiobacillus ssp. and 4- control (no fertilizer. The results showed the effect of cover crops on seed number and seed weight per plant, biological and seed yield was significant, as the seed yield increased of 9 %. In general, biofertilizers showed superiority due to the most studied traits compared to control. Nitroxin, PSB and biosulfur increased biological yield of 44, 28 and 26 % compared to control, respectively. Cover crops and biofertilizers interactions, showed significant effect on all studied traits, as the highest and the lowest harvest index resulted in cover crop combined with biofertilizers (22.1% and cultivation and no cultivation of cover crops combined with control (15.3%, respectively. The highest seed oil and protein content resulted from cover crops plus biofertilizers (42.4% and cover crops plus PSB (22.5%, respectively. In general, the results showed cover crops cultivation in combination with biofertilizers application could be an ecological alternative for chemical fertilizers, in addition of achieving advantages of cover crops. According to the results, it should be possible to design an ecological cropping system and produce appropriate and healthy

  16. Evaluation of Brevibacillus brevis as a potential plant growth promoting rhizobacteria for cotton (Gossypium hirsutum) crop.

    Science.gov (United States)

    Nehra, Vibha; Saharan, Baljeet Singh; Choudhary, Madhu

    2016-01-01

    The present investigation was undertaken to isolate, screen and evaluate a selected promising PGPR Brevibacillus brevis on cotton crop. Out of 156 bacterial isolates one of the most promising isolate was analyzed for the various PGP traits. A seed germination analysis was conducted with cotton seeds to evaluate the potential of the isolate to promote plant growth. The bacterial isolate was checked for its growth and survival at high temperatures. The isolate was also analyzed for the PGP traits exhibited after the heat treatment. To identify the isolate morphological, biochemical and molecular characterization was performed. The isolate was found positive for many of the PGP attributes like IAA, ARA, anti-fungal activity and ammonia production. Effect of seed bacterization on various plant growth parameters was used as an indicator. The isolate showed significant growth and exhibited various PGP traits at high temperature making it suitable as an inoculant for cotton crop. Isolate was identified as Brevibacillus brevis [SVC(II)14] based on phenotypic as well as genotypic attributes and after conducting this research we propose that the B. brevis which is reported for the first time for its PGP potential in cotton, exerts its beneficial effects on cotton crop through combined modes of actions.

  17. Occurrence of plant growth-promoting traits in clover-nodulating rhizobia strains isolated from different soils in Rio Grande do Sul state Ocorrência de características de promoção de crescimento em rizóbios noduladores de trevo isolados de solos do Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Luciano Kayser Vargas

    2009-10-01

    Full Text Available In the last decades, the use of plant growth-promoting rhizobacteria has become an alternative to improve crop production. Rhizobium leguminosarum biovar trifolii is one of the most promising rhizobacteria and is even used with non-legume plants. This study investigated in vitro the occurrence of plant growth-promoting characteristics in several indigenous R. leguminosarum biovar trifolii isolated from soils in the State of Rio Grande do Sul, Brazil. Isolates were obtained at 11 locations and evaluated for indoleacetic acid and siderophore production and inorganic phosphate solubilization. Ten isolates were also molecularly characterized and tested for antagonism against a phytopathogenic fungus and for plant growth promotion of rice seedlings. Of a total of 252 isolates, 59 produced indoleacetic acid, 20 produced siderophores and 107 solubilized phosphate. Some degree of antagonism against Verticillium sp. was observed in all tested isolates, reducing mycelial growth in culture broth. Isolate AGR-3 stood out for increasing root length of rice seedlings, while isolate ELD-18, besides increasing root length in comparison to the uninoculated control, also increased the germination speed index, shoot length, and seedling dry weight. These results confirm the potential of some strains of R. leguminosarum biovar trifolii as plant growth-promoting rhizobacteria.Nas últimas décadas, o uso de rizobactérias promotoras de crescimento de plantas tem se mostrado uma alternativa para aumentar a produção vegetal. Rhizobium leguminosarum biovar trifolii está entre as mais promissoras rizobactérias e tem sido usada também em não leguminosas. O presente trabalho analisou in vitro a ocorrência de características de promoção de crescimento vegetal em isolados de R. leguminosarum biovar trifolii nativos de solos do Rio Grande do Sul. Os isolados foram obtidos de 11 localidades e avaliados quanto à produção de ácido indolacético, produção de

  18. Paenibacillus polymyxa A26 sfp-type phosphopantetheinyl transferase inactivation limits bacterial antagonism against Fusarium graminearum but not of F. culmorum

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    Islam A eAbd El Daim

    2015-05-01

    Full Text Available Fusarium graminearum and F. culmorum are the causing agents of a destructive disease known as Fusarium head blight (FHB. FHB is a re-emerging disease in small grain cereals which impairs both the grain yield and the quality. Most serious consequence is the contamination of grain with Fusarium mycotoxins that are severe threat to humans and animals. Biological control has been suggested as one of the integrated management strategies to control FHB. Paenibacillus polymyxa is considered as a promising biocontrol agent due to its unique antibiotic spectrum. In order to optimize strain A26 production, formulation and application strategies traits important for its compatibility need to be revealed. Here we developed a toolbox comprising of dual culture plate assays and wheat kernel assays including simultaneous monitoring of FHB causing pathogens A26 and mycotoxins produced. Using this system we show that, besides generally known lipopeptide antibiotic production by P. polymyxa, biofilm formation ability may play a crucial role in the case of stain A26 F. culmorum antagonism.

  19. American foulbrood of the honey bee: occurrence and distribution of different genotypes of Paenibacillus larvae in the administrative district of Arnsberg (North Rhine-Westphalia).

    Science.gov (United States)

    Peters, M; Kilwinski, J; Beringhoff, A; Reckling, D; Genersch, E

    2006-03-01

    Between March 2003 and October 2004, Paenibacillus larvae, the aetiological agent of American foulbrood disease of the honey bee, was isolated from broodcombs and honey samples of 54 apiaries in the administrative district of Arnsberg (North Rhine-Westphalia, Germany). Genotyping of 176 P. larvae isolates with repetitive element polymerase chain reaction fingerprinting (rep-PCR) using BOX A1R and MBO REP1 primers revealed five different genotypes (AB, Ab, ab, ass, Acapital BE, Cyrillic). In samples of three apiaries, more than one genotype was detected. A combination of two genotypes was isolated from honey samples of the same hive two times (ab/ass and Ab/ab). The five genotypes were not randomly distributed in the district, but revealed a certain geographical clustering. Possible factors with impact on the genotype diversity and the distribution pattern are discussed.

  20. Purification and characterization of a novel milk-clotting metalloproteinase from Paenibacillus spp. BD3526.

    Science.gov (United States)

    Hang, Feng; Wang, Qinbo; Hong, Qing; Liu, Peiyi; Wu, Zhengjun; Liu, Zhenmin; Zhang, Hao; Chen, Wei

    2016-04-01

    In this study, a milk-clotting enzyme (MCE) isolated from Paenibacillus spp. BD3526 was purified and characterized. The MCE was purified 8.9-fold with a 10.11% recovery using ammonium sulfate precipitation and anion-exchange chromatography and the specific milk-clotting activity (MCA) reached 6791.73 SU/mg. The enzyme was characterized as a 35kDa metalloproteinase, and the zymogen of which was encoded by a 1671 bp gene named zinc metalloproteinase precursor (zmp) with a predicted molecular weight of 59.6 kDa. The optimal temperature for MCA and proteolytic activity (PA) was 65°C and 60°C, respectively. The enzyme was stable over a pH range of 5.0-9.0 and at temperatures below 50°C. The MCA was completely inactivated when the enzyme was heated at 60°C for 30 min, and the PA was totally inactivated for 20 and 10 min when the enzyme was heated at 55°C and 60°C, respectively. The BD3526 enzyme was preferentially active towards κ-casein (κ-CN) and β-casein (β-CN), as determined by sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE), whereas the hydrolysis of αs-casein (αs-CN) was slow and comparable to that caused by chymosin and asparatic acid proteinase from Rhizomucor miehei. The cleavage site of the metalloproteinase in κ-CN was located at the Met106-Ala107 bond, as determined by mass spectrometry analysis. Copyright © 2016. Published by Elsevier B.V.

  1. Production of the catechol type siderophore bacillibactin by the honey bee pathogen Paenibacillus larvae.

    Science.gov (United States)

    Hertlein, Gillian; Müller, Sebastian; Garcia-Gonzalez, Eva; Poppinga, Lena; Süssmuth, Roderich D; Genersch, Elke

    2014-01-01

    The Gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood. This bacterial infection of honey bee brood is a notifiable epizootic posing a serious threat to global honey bee health because not only individual larvae but also entire colonies succumb to the disease. In the recent past considerable progress has been made in elucidating molecular aspects of host pathogen interactions during pathogenesis of P. larvae infections. Especially the sequencing and annotation of the complete genome of P. larvae was a major step forward and revealed the existence of several giant gene clusters coding for non-ribosomal peptide synthetases which might act as putative virulence factors. We here present the detailed analysis of one of these clusters which we demonstrated to be responsible for the biosynthesis of bacillibactin, a P. larvae siderophore. We first established culture conditions allowing the growth of P. larvae under iron-limited conditions and triggering siderophore production by P. larvae. Using a gene disruption strategy we linked siderophore production to the expression of an uninterrupted bacillibactin gene cluster. In silico analysis predicted the structure of a trimeric trithreonyl lactone (DHB-Gly-Thr)3 similar to the structure of bacillibactin produced by several Bacillus species. Mass spectrometric analysis unambiguously confirmed that the siderophore produced by P. larvae is identical to bacillibactin. Exposure bioassays demonstrated that P. larvae bacillibactin is not required for full virulence of P. larvae in laboratory exposure bioassays. This observation is consistent with results obtained for bacillibactin in other pathogenic bacteria.

  2. Distribution of Paenibacillus larvae spores inside honey bee colonies and its relevance for diagnosis.

    Science.gov (United States)

    Gillard, M; Charriere, J D; Belloy, L

    2008-09-01

    One of the most important factors affecting the development of honey bee colonies is infectious diseases such as American foulbrood (AFB) caused by the spore forming Gram-positive bacterium Paenibacillus larvae. Colony inspections for AFB clinical symptoms are time consuming. Moreover, diseased cells in the early stages of the infection may easily be overlooked. In this study, we investigated whether it is possible to determine the sanitary status of a colony based on analyses of different materials collected from the hive. We analysed 237 bee samples and 67 honey samples originating from 71 colonies situated in 13 apiaries with clinical AFB occurrences. We tested whether a difference in spore load among bees inside the whole hive exists and which sample material related to its location inside the hive was the most appropriate for an early AFB diagnosis based on the culture method. Results indicated that diagnostics based on analysis of honey samples and bees collected at the hive entrance are of limited value as only 86% and 83%, respectively, of samples from AFB-symptomatic colonies were positive. Analysis of bee samples collected from the brood nest, honey chamber, and edge frame allowed the detection of all colonies showing AFB clinical symptoms. Microbiological analysis showed that more than one quarter of samples collected from colonies without AFB clinical symptoms were positive for P. larvae. Based on these results, we recommend investigating colonies by testing bee samples from the brood nest, edge frame or honey chamber for P. larvae spores.

  3. The Fungi in Old Paper Mixed Bio-sludge Compost and Its Metabolite and PGPR Effect

    OpenAIRE

    森本, 正則; 若山, 晃子; 駒井, 功一郎

    2005-01-01

    [Synopsis] Sometime, the compost products made from bio-sludge and containing paper strips, showed plant growth promoting effect by field application. We have evaluated to separating various fungi from biosludge compost that have PGPR (Plant Growth Promoting Rhizobacteria) effect against some crops by inoculating test into the incubation soil. Test fungi separated from the compost using multiple dilution method and colonization on the PDA agar plate. And, the surface of autoclaved oat serial...

  4. Pitting Corrosion Within Bioreactors for Space Cell-Culture Contaminated by Paenibacillus glucanolyticus, a Case Report

    Science.gov (United States)

    Barravecchia, Ivana; Cesari, Chiara De; Pyankova, Olga V.; Scebba, Francesca; Mascherpa, Marco Carlo; Vecchione, Alessandra; Tavanti, Arianna; Tedeschi, Lorena; Angeloni, Debora

    2018-05-01

    Performing cell biology experiments in space imposes the use of hardware that essentially allows fluid exchange in a contained environment. Given the technical and logistical peculiarities, the limited opportunities and the high cost of access to space, a great effort during mission preparation of scientific studies is devoted to preventing loss of the experiment. The European Space Agency (ESA) requires, at the end of the preparation phase, the execution of an Experiment Sequence Test (EST), a dry-run version of the space experiment to check all procedures. At conclusion of the EST of our experiment `ENDO' (ESA ILSRA-2009-1026), we found pitting corrosion of metal parts and biofilm formation within the cell-culture devices. The subsequent chemical (spectral assays), instrumental (OGP SmartScope) and microbiological (MALDI-TOF, 16S rRNA gene sequencing) investigations allowed the identification in contaminated material of Paenibacillus glucanolyticus, a ubiquitous, aerobic, facultative anaerobic, endospore forming, acid-producing, Gram-positive microorganism. A concurrence of P. glucanolyticus contamination and galvanic corrosion determined massive fouling, rust precipitation and damage to cells and cell-culture devices being, to our knowledge, the association between this microbe and corrosion never reported before in literature. As a consequence of the episode a critical procedure of experiment set up, i.e. hardware sterilization, was modified. The ENDO experiment was successfully launched to the International Space Station on September 2nd 2015 and returned to the PI laboratory on September 13th, with all cell culture samples in optimal condition.

  5. Pitting Corrosion Within Bioreactors for Space Cell-Culture Contaminated by Paenibacillus glucanolyticus, a Case Report

    Science.gov (United States)

    Barravecchia, Ivana; Cesari, Chiara De; Pyankova, Olga V.; Scebba, Francesca; Mascherpa, Marco Carlo; Vecchione, Alessandra; Tavanti, Arianna; Tedeschi, Lorena; Angeloni, Debora

    2018-02-01

    Performing cell biology experiments in space imposes the use of hardware that essentially allows fluid exchange in a contained environment. Given the technical and logistical peculiarities, the limited opportunities and the high cost of access to space, a great effort during mission preparation of scientific studies is devoted to preventing loss of the experiment. The European Space Agency (ESA) requires, at the end of the preparation phase, the execution of an Experiment Sequence Test (EST), a dry-run version of the space experiment to check all procedures. At conclusion of the EST of our experiment `ENDO' (ESA ILSRA-2009-1026), we found pitting corrosion of metal parts and biofilm formation within the cell-culture devices. The subsequent chemical (spectral assays), instrumental (OGP SmartScope) and microbiological (MALDI-TOF, 16S rRNA gene sequencing) investigations allowed the identification in contaminated material of Paenibacillus glucanolyticus, a ubiquitous, aerobic, facultative anaerobic, endospore forming, acid-producing, Gram-positive microorganism. A concurrence of P. glucanolyticus contamination and galvanic corrosion determined massive fouling, rust precipitation and damage to cells and cell-culture devices being, to our knowledge, the association between this microbe and corrosion never reported before in literature. As a consequence of the episode a critical procedure of experiment set up, i.e. hardware sterilization, was modified. The ENDO experiment was successfully launched to the International Space Station on September 2nd 2015 and returned to the PI laboratory on September 13th, with all cell culture samples in optimal condition.

  6. Mathematical modeling of the whole expanded bed adsorption process to recover and purify chitosanases from the unclarified fermentation broth of Paenibacillus ehimensis.

    Science.gov (United States)

    de Araújo Padilha, Carlos Eduardo; Fortunato Dantas, Paulo Victor; de Sousa, Francisco Canindé; de Santana Souza, Domingos Fabiano; de Oliveira, Jackson Araújo; de Macedo, Gorete Ribeiro; Dos Santos, Everaldo Silvino

    2016-12-15

    In this study, a general rate model was applied to the entire process of expanded bed adsorption chromatography (EBAC) for the chitosanases purification protocol from unclarified fermentation broth produced by Paenibacillus ehimensis using the anionic adsorbent Streamline ® DEAE. For the experiments performed using the expanded bed, a homemade column (2.6cm×30.0cm) was specially designed. The proposed model predicted the entire EBA process adequately, giving R 2 values higher than 0.85 and χ 2 as low as 0.351 for the elution step. Using the validated model, a 3 3 factorial design was used to investigate other non-tested conditions as input. It was observed that the superficial velocity during loading and washing steps, as well as the settled bed height, has a strong positive effect on the F objective function used to evaluate the production of the purified chitosanases. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses.

    Directory of Open Access Journals (Sweden)

    Hoang Hoa Long

    Full Text Available BACKGROUND: All plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. Changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (PGP rhizobacteria which can decrease ethylene (ET levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC deaminase or produce indole acetic acid (IAA. Whether these common PGP mechanisms work similarly for different plant species has not been rigorously tested. METHODOLOGY/PRINCIPAL FINDINGS: We isolated bacterial endophytes from field-grown Solanum nigrum; characterized PGP traits (ACC deaminase activity, IAA production, phosphate solubilization and seedling colonization; and determined their effects on their host, S. nigrum, as well as on another Solanaceous native plant, Nicotiana attenuata. In S. nigrum, a majority of isolates that promoted root growth were associated with ACC deaminase activity and IAA production. However, in N. attenuata, IAA but not ACC deaminase activity was associated with root growth. Inoculating N. attenuata and S. nigrum with known PGP bacteria from a culture collection (DSMZ reinforced the conclusion that the PGP effects are not highly conserved. CONCLUSIONS/SIGNIFICANCE: We conclude that natural endophytic bacteria with PGP traits do not have general and predictable effects on the growth and fitness of all host plants, although the underlying mechanisms are conserved.

  8. Diversity of Antifungal Compounds-Producing Bacillus spp. Isolated from Rhizosphere of Soybean Plant Based on ARDRA and 16S rRNA

    Directory of Open Access Journals (Sweden)

    ARIS TRI WAHYUDI

    2010-09-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR play an important role in improvement of seed germination, root development, and water utilization by plants. These rhizobacteria can stimulate plant growth directly by producing growth hormones or indirectly by producing antifungal compounds/antibiotics to suppress phytopathogenic fungi. The objective of this research was to analyze the diversity of 22 antifungal-producing rhizobacteria of Bacillus sp. isolated from rhizosphere of soybean plant based on Amplified rDNA Restriction Analysis (ARDRA and 16S rRNA Sequence. Restriction enzymes in ARDRA analysis, HinfI, HaeIII, and RsaI were used to digest 22 16S rDNA amplified from Bacillus sp. genomes. Based on this analysis, genetic diversity of 22 Bacillus sp. producing antifungal compounds were classified into eight different groups. Moreover, six selected isolates randomly from each ARDRA group that have strong activity to suppress fungal growth were analyzed for their 16S rDNA sequences compared with reference strains. The distributions of these isolates were genetically diverse on several species of Bacillus sp. such as B. subtilis, B. cereus, and B. fusiformis. ARDRA is a reliable technique to analyze genetic diversity of Bacillus sp. community in the rhizosphere.

  9. Streptomyces cameroonensis sp. nov., a Geldanamycin Producer That Promotes Theobroma cacao Growth.

    Science.gov (United States)

    Boudjeko, Thaddée; Tchinda, Romaric Armel Mouafo; Zitouni, Mina; Nana, Joëlle Aimée Vera Tchatchou; Lerat, Sylvain; Beaulieu, Carole

    2017-03-31

    The taxonomy of an actinobacterial strain, designated JJY4 T , was established using a polyphasic approach. JJY4 T was isolated from the rhizosphere of Chromolaena odorata in Yaoundé (Cameroon) during a project for the selection of biological control agents. Strain JJY4 T exhibited antimicrobial activities against bacteria, fungi, and oomycetes. Strain JJY4 T also exhibited the traits of plant growth-promoting rhizobacteria such as the solubilization of inorganic phosphate, production of siderophores and indole-3-acetic acid, and 1-aminocyclopropane-1-carboxylate deaminase activity. In planta assays performed on cocoa plantlets confirmed that strain JJY4 T exhibited strong abilities to promote plant growth and protect against Phytophthora megakarya, the main causal agent of cocoa pod rot. The formation of rugose-ornamented spores in spiral spore chains by strain JJY4 T is a typical feature of members found in the Streptomyces violaceusniger clade and, similar to some members of the clade, strain JJY4 T produces geldanamycin. A phylogenetic analysis based on 16S rRNA gene sequences confirmed this classification and suggests that strain JJY4 T be added to the subclade constituted of the type strains Streptomyces malaysiensis DSM 41697 T and Streptomyces samsunensis DSM 42010 T . However, DNA-DNA relatedness and physiological characteristics allowed for the differentiation of strain JJY4 T from its closest phylogenetic relatives. Based on these results, strain JJY4 T (=NRRL B-65369, =NBRC 112705) appears to represent a novel species in the S. violaceusniger clade for which the proposed name is Streptomyces cameroonensis sp. nov.

  10. Root exudate-induced alterations in Bacillus cereus cell wall contribute to root colonization and plant growth promotion.

    Directory of Open Access Journals (Sweden)

    Swarnalee Dutta

    Full Text Available The outcome of an interaction between plant growth promoting rhizobacteria and plants may depend on the chemical composition of root exudates (REs. We report the colonization of tobacco, and not groundnut, roots by a non-rhizospheric Bacillus cereus (MTCC 430. There was a differential alteration in the cell wall components of B. cereus in response to the REs from tobacco and groundnut. Attenuated total reflectance infrared spectroscopy revealed a split in amide I region of B. cereus cells exposed to tobacco-root exudates (TRE, compared to those exposed to groundnut-root exudates (GRE. In addition, changes in exopolysaccharides and lipid-packing were observed in B. cereus grown in TRE-amended minimal media that were not detectable in GRE-amended media. Cell-wall proteome analyses revealed upregulation of oxidative stress-related alkyl hydroperoxide reductase, and DNA-protecting protein chain (Dlp-2, in response to GRE and TRE, respectively. Metabolism-related enzymes like 2-amino-3-ketobutyrate coenzyme A ligase and 2-methylcitrate dehydratase and a 60 kDa chaperonin were up-regulated in response to TRE and GRE. In response to B. cereus, the plant roots altered their exudate-chemodiversity with respect to carbohydrates, organic acids, alkanes, and polyols. TRE-induced changes in surface components of B. cereus may contribute to successful root colonization and subsequent plant growth promotion.

  11. A novel interaction between plant-beneficial rhizobacteria and roots: colonization induces corn resistance against the root herbivore Diabrotica speciosa.

    Directory of Open Access Journals (Sweden)

    Franciele Santos

    Full Text Available A number of soil-borne microorganisms, such as mycorrhizal fungi and rhizobacteria, establish mutualistic interactions with plants, which can indirectly affect other organisms. Knowledge of the plant-mediated effects of mutualistic microorganisms is limited to aboveground insects, whereas there is little understanding of what role beneficial soil bacteria may play in plant defense against root herbivory. Here, we establish that colonization by the beneficial rhizobacterium Azospirillum brasilense affects the host selection and performance of the insect Diabrotica speciosa. Root larvae preferentially orient toward the roots of non-inoculated plants versus inoculated roots and gain less weight when feeding on inoculated plants. As inoculation by A. brasilense induces higher emissions of (E-β-caryophyllene compared with non-inoculated plants, it is plausible that the non-preference of D. speciosa for inoculated plants is related to this sesquiterpene, which is well known to mediate belowground insect-plant interactions. To the best of our knowledge, this is the first study showing that a beneficial rhizobacterium inoculant indirectly alters belowground plant-insect interactions. The role of A. brasilense as part of an integrative pest management (IPM program for the protection of corn against the South American corn rootworm, D. speciosa, is considered.

  12. A complex molecular interplay of auxin and ethylene signaling pathways is involved in Arabidopsis growth promotion by Burkholderia phytofirmans PsJN

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    María Josefina Poupin

    2016-04-01

    Full Text Available Modulation of phytohormones homeostasis is one of the proposed mechanisms to explain plant growth promotion induced by beneficial rhizobacteria (PGPR. However, there is still limited knowledge about the molecular signals and pathways underlying these beneficial interactions. Even less is known concerning the interplay between phytohormones in plants inoculated with PGPR. Auxin and ethylene are crucial hormones in the control of plant growth and development, and recent studies report an important and complex crosstalk between them in the regulation of different plant developmental processes. The objective of this work was to study the role of both hormones in the growth promotion of Arabidopsis thaliana plants induced by the well-known PGPR Burkholderia phytofirmans PsJN. For this, the spatiotemporal expression patterns of several genes related to auxin biosynthesis, perception and response and ethylene biosynthesis were studied, finding that most of these genes showed specific transcriptional regulations after inoculation in roots and shoots. PsJN-growth promotion was not observed in Arabidopsis mutants with an impaired ethylene (ein2-1 or auxin (axr1-5 signaling. Even, PsJN did not promote growth in an ethylene overproducer (eto2, indicating that a fine regulation of both hormones signaling and homeostasis is necessary to induce growth of the aerial and root tissues. Auxin polar transport is also involved in growth promotion, since PsJN did not promote primary root growth in the pin2 mutant or under chemical inhibition of transport in wild type plants. Finally, a key role for ethylene biosynthesis was found in the PsJN-mediated increase in root hair number. These results not only give new insights of PGPR regulation of plant growth but also are also useful to understand key aspects of Arabidopsis growth control.

  13. Transcriptional response of honey bee larvae infected with the bacterial pathogen Paenibacillus larvae.

    Science.gov (United States)

    Cornman, Robert Scott; Lopez, Dawn; Evans, Jay D

    2013-01-01

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and a general immunity is achieved by larvae as they age, the basis of which has not been identified. To quickly identify a pool of candidate genes responsive to P. larvae infection, we sequenced transcripts from larvae inoculated with P. larvae at 12 hours post-emergence and incubated for 72 hours, and compared expression levels to a control cohort. We identified 75 genes with significantly higher expression and six genes with significantly lower expression. In addition to several antimicrobial peptides, two genes encoding peritrophic-matrix domains were also up-regulated. Extracellular matrix proteins, proteases/protease inhibitors, and members of the Osiris gene family were prevalent among differentially regulated genes. However, analysis of Drosophila homologs of differentially expressed genes revealed spatial and temporal patterns consistent with developmental asynchrony as a likely confounder of our results. We therefore used qPCR to measure the consistency of gene expression changes for a subset of differentially expressed genes. A replicate experiment sampled at both 48 and 72 hours post infection allowed further discrimination of genes likely to be involved in host response. The consistently responsive genes in our test set included a hymenopteran-specific protein tyrosine kinase, a hymenopteran specific serine endopeptidase, a cytochrome P450 (CYP9Q1), and a homolog of trynity, a zona pellucida domain protein. Of the known honey bee antimicrobial peptides, apidaecin was responsive at both time-points studied whereas hymenoptaecin was more consistent in its level of change between biological replicates and had the greatest increase in expression by RNA-seq analysis.

  14. Evaluation of indigenous rhizobacterial strains with reduced dose of chemical fertilizer towards growth and yield of mustard (Brassica campestris under old alluvial soil zone of West Bengal, India

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    Shampa Dutta

    2017-12-01

    Full Text Available A field experiment had been carried out in the Crop Research and Seed Multiplication Farm of The University of Burdwan, West Bengal, India during the two consecutive winter seasons of 2011-2012 and 2012-2013 to study the effect of indigenous rhizospheric bacterial strains on growth, physiology and yield of mustard variety. Pseudomonas putida, Burkholderia cepacia, Burkholderia sp. and their mixture were used as seed inoculants for mustard cultivation. The experiment was laid down in a randomized complete block design (RCBD with three replications. Results revealed that indigenous inoculation (with reduced dose of chemical fertilizer significantly increased (p < 0.05 the yield of mustard as compared to uninoculated control (full recommended dose of NPK fertilizers. A combination treatment of biofertilizer and chemical fertilizer also increased plant height, plant biomass and other yield components compared to control. The comprehensive approach of plant growth promoting rhizobacteria (PGPR in agriculturally important crops should be carried out to explore the hidden potential of PGPR and to promote the quality and yield of crop under field conditions. Keywords: Indigenous rhizobacteria, Mustard, PGPR, Yield

  15. Effect of Hydropriming and Biopriming on Seed Germination and Growth of Two Mexican Fir Tree Species in Danger of Extinction

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    Ramón Zulueta-Rodríguez

    2015-09-01

    Full Text Available Abies spp. in general have been shown to need a period of cold stratification to break dormancy and germinate, but this can be very time consuming. In this study, hydropriming by itself and in combination with biopriming was carried out on Abies hickelii and Abies religiosa seeds. For biopriming, three species of plant growth promoting rhizobacteria ( Pseudomonas fluorescens, P. putida and Bacillus subtilis were tested. The purpose was to determine if germination and growth could be improved for these two endangered species. Our results demonstrated that treating A. hickelii and A. religiosa with both hydropriming and biopriming with certain strains of Plant Growth-Promoting Rhizobacteria (PGPR could improve germination rates up to 91% for A. hickelii and up to 68% for A. religiosa. Importantly, these treatments showed no significant negative impact on the growth of A. religiosa and actually improved growth in A. hickelii. The application of both hydropriming and biopriming offer possibly an alternative methodology to improve germination, survival and preservation of these fir tree species of Mexico that are at risk of extinction.

  16. Deciphering the role of Paenibacillus strain Q8 in the organic matter recycling in the acid mine drainage of Carnoulès

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    Delavat François

    2012-02-01

    Full Text Available Abstract Background The recycling of the organic matter is a crucial function in any environment, especially in oligotrophic environments such as Acid Mine Drainages (AMDs. Polymer-degrading bacteria might play an important role in such ecosystem, at least by releasing by-products useful for the rest of the community. In this study, physiological, molecular and biochemical experiments were performed to decipher the role of a Paenibacillus strain isolated from the sediment of Carnoulès AMD. Results Even though Paenibacillus sp. strain Q8 was isolated from an oligotrophic AMD showing an acidic pH, it developed under both acidic and alkaline conditions and showed a heterotrophic metabolism based on the utilization of a broad range of organic compounds. It resisted to numerous metallic stresses, particularly high arsenite (As(III concentrations (> 1,800 mg/L. Q8 was also able to efficiently degrade polymers such as cellulose, xylan and starch. Function-based screening of a Q8 DNA-library allowed the detection of 15 clones with starch-degrading activity and 3 clones with xylan-degrading activity. One clone positive for starch degradation carried a single gene encoding a "protein of unknown function". Amylolytic and xylanolytic activities were measured both in growing cells and with acellular extracts of Q8. The results showed the ability of Q8 to degrade both polymers under a broad pH range and high As(III and As(V concentrations. Activity measurements allowed to point out the constitutive expression of the amylase genes and the mainly inducible expression of the xylanase genes. PACE demonstrated the endo-acting activity of the amylases and the exo-acting activity of the xylanases. Conclusions AMDs have been studied for years especially with regard to interactions between bacteria and the inorganic compartment hosting them. To date, no study reported the role of microorganisms in the recycling of the organic matter. The present work suggests that

  17. Differential oxidative and antioxidative response of duckweed Lemna minor toward plant growth promoting/inhibiting bacteria.

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    Ishizawa, Hidehiro; Kuroda, Masashi; Morikawa, Masaaki; Ike, Michihiko

    2017-09-01

    Bacteria colonizing the plant rhizosphere are believed to positively or negatively affect the host plant productivity. This feature has inspired researchers to engineer such interactions to enhance crop production. However, it remains to be elucidated whether rhizobacteria influences plant oxidative stress vis-a-vis other environmental stressors, and whether such influence is associated with their growth promoting/inhibiting ability. In this study, two plant growth-promoting bacteria (PGPB) and two plant growth-inhibiting bacteria (PGIB) were separately inoculated into axenic duckweed (Lemna minor) culture under laboratory conditions for 4 and 8 days in order to investigate their effects on plant oxidative stress and antioxidant activities. As previously characterized, the inoculation of PGPB and PGIB strains accelerated and reduced the growth of L. minor, respectively. After 4 and 8 days of cultivation, compared to the PGPB strains, the PGIB strains induced larger amounts of O 2 •- , H 2 O 2 , and malondialdehyde (MDA) in duckweed, although all bacterial strains consistently increased O 2 •- content by two times more than that in the aseptic control plants. Activities of five antioxidant enzymes were also elevated by the inoculation of PGIB, confirming the severe oxidative stress condition in plants. These results suggest that the surface attached bacteria affect differently on host oxidative stress and its response, which degree correlates negatively to their effects on plant growth. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. [Evaluation of the Epsilometer (Etest) method for the detection of tetracycline susceptibility in Paenibacillus larvae, the causal agent of American foulbrood disease of honeybees].

    Science.gov (United States)

    Alippi, Adriana M; Reynaldi, Francisco J; López, Ana C

    2013-01-01

    American foulbrood (AFB) is a bacterial disease caused by the spore-forming, grampositive bacterium Paenibacillus larvae, which affects honeybee broods worldwide. The aim of this work was to compare the Epsilometer test (Etest) to the agar dilution method for testing a collection of 22 P. larvae strains to tetracycline by using MYPGP and Iso- Sensitest agars. Results showed that a categorical agreement of 100% was found when using Iso-Sensitest, while a categorical agreement of 86.36% was found (with 3 minor errors) when MYPGP was tested. In conclusion, the Etest could be a rapid and reliable method for testing MIC values of tetracycline in P. larvae only when used in combination with Iso-Sensitest agar. Nevertheless, these results should be confirmed with future studies involving a larger number of isolates. Copyright © 2013 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  19. Impact of soil salinity on the plant-growth – promoting and biological control abilities of root associated bacteria

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    Dilfuza Egamberdieva

    2017-11-01

    Full Text Available The effectiveness of plant growth – promoting bacteria is variable under different biotic and abiotic conditions. Abiotic factors may negatively affect the beneficial properties and efficiency of the introduced PGPR inoculants. The aim of this study was to evaluate the effect of plant growth – promoting rhizobacteria on plant growth and on the control of foot and root rot of tomatoes caused by Fusarium solani under different soil salinity conditions. Among the five tested strains, only Pseudomonas chlororaphis TSAU13, and Pseudomonas extremorientalis TSAU20 were able to stimulate plant growth and act as biological controls of foot and root rot disease of tomato. The soil salinity did not negatively affect the beneficial impacts of these strains, as they were able to colonize and survive on the roots of tomato plants under both saline and non-saline soil conditions. The improved plant height and fruit yield of tomato was also observed for plants inoculated with P. extremorientalis TSAU20. Our results indicated that, saline condition is not crucial factor in obtaining good performance with respect to the plant growth stimulating and biocontrol abilities of PGPR strains. The bacterial inoculant also enhanced antioxidant enzymes activities thereby preventing ROS induced oxidative damage in plants, and the proline concentrations in plant tissue that play an important role in plant stress tolerance.

  20. Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Grosskinsky, D. K.; Tafner, R.; Moreno, M. V.; Stenglein, S. A.; Garcia de Salamone, I. E.; Nelson, L. M.; Novák, Ondřej; Strnad, Miroslav; van der Graaff, E.; Roitsch, Thomas

    2016-01-01

    Roč. 6, MAR 17 (2016), s. 23310 ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1204; GA ČR GA15-22322S; GA MŠk(CZ) LO1415 Institutional support: RVO:61389030 ; RVO:67179843 Keywords : GROWTH-PROMOTING RHIZOBACTERIA * PLANT-GROWTH * SALICYLIC-ACID Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.259, year: 2016

  1. Biological Role of Paenilarvins, Iturin-Like Lipopeptide Secondary Metabolites Produced by the Honey Bee Pathogen Paenibacillus larvae.

    Science.gov (United States)

    Hertlein, Gillian; Seiffert, Marlene; Gensel, Sebastian; Garcia-Gonzalez, Eva; Ebeling, Julia; Skobalj, Ranko; Kuthning, Anja; Süssmuth, Roderich D; Genersch, Elke

    2016-01-01

    The Gram-positive bacterium Paenibacillus larvae (P. larvae) is the causative agent of a deadly honey bee brood disease called American Foulbrood (AFB). AFB is a notifiable epizootic in most countries and, hence, P. larvae is of considerable relevance for veterinarians and apiculturists alike. Over the last decade, much progress has been made in the understanding of the (patho)biology of P. larvae. Recently, several non-ribosomally produced peptides (NRP) and peptide/polyketide (NRP/PK) hybrids produced by P. larvae were identified. Among these NRPs were iturin-like lipopeptides, the paenilarvins A-C. Iturins are known to exhibit strong anti-fungal activity; for some iturins, cytotoxic activity towards mammalian erythrocytes and human cancer cell lines are described. We here present our results on the analysis of the natural function of the paenilarvins during pathogenesis of P. larvae infections. We demonstrated production of paenilarvins in infected larvae. However, we could neither demonstrate cytotoxicity of paenilarvins towards cultured insect cells nor towards larvae in feeding assays. Accordingly, exposure bioassays performed with larvae infected by wild-type P. larvae and a knockout mutant of P. larvae lacking production of paenilarvins did not substantiate a role for the paenilarvins as virulence factor. Further experiments are necessary to analyze the relevance of the paenilarvins' anti-fungal activity for P. larvae infections in the presence of fungal competitors in the larval midgut or cadaver.

  2. A Simplified Method for Gene Knockout and Direct Screening of Recombinant Clones for Application in Paenibacillus polymyxa.

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    Seong-Bin Kim

    Full Text Available Paenibacillus polymyxa is a bacterium widely used in agriculture, industry, and environmental remediation because it has multiple functions including nitrogen fixation and produces various biologically active compounds. Among these compounds are the antibiotics polymyxins, and the bacterium is currently being reassessed for medical application. However, a lack of genetic tools for manipulation of P. polymyxa has limited our understanding of the biosynthesis of these compounds.To facilitate an understanding of the genetic determinants of the bacterium, we have developed a system for marker exchange mutagenesis directly on competent cells of P. polymyxa under conditions where homologous recombination is enhanced by denaturation of the suicide plasmid DNA. To test this system, we targeted P. polymyxa α-and β-amylase genes for disruption. Chloramphenicol or erythromycin resistance genes were inserted into the suicide plasmid pGEM7Z-f+ (Promega. To mediate homologous recombination and replacement of the targeted genes with the antibiotic resistance genes nucleotide sequences of the α-and β-amylase genes were cloned into the plasmid flanking the antibiotic resistance genes.We have created a simple system for targeted gene deletion in P. polymyxa E681. We propose that P. polymyxa isogenic mutants could be developed using this system of marker exchange mutagenesis. α-and β-amylase genes provide a useful tool for direct recombinant screening in P. polymyxa.

  3. Isolation and identification of a new intracellular antimicrobial peptide produced by Paenibacillus alvei AN5.

    Science.gov (United States)

    Alkotaini, Bassam; Anuar, Nurina; Kadhum, Abdul Amir Hassan; Sani, Asmahani Azira Abdu

    2014-04-01

    A wild-type, Gram-positive, rod-shaped, endospore-forming and motile bacteria has been isolated from palm oil mill sludge in Malaysia. Molecular identification using 16S rRNA gene sequence analysis indicated that the bacteria belonged to genus Paenibacillus. With 97 % similarity to P. alvei (AUG6), the isolate was designated as P. alvei AN5. An antimicrobial compound was extracted from P. alvei AN5-pelleted cells using 95 % methanol and was then lyophilized. Precipitates were re-suspended in phosphate buffered saline (PBS), producing an antimicrobial crude extract (ACE). The ACE showed antimicrobial activity against Salmonella enteritidis ATCC 13076, Escherichia coli ATCC 29522, Bacillus cereus ATCC 14579 and Lactobacillus plantarum ATCC 8014. By using SP-Sepharose cation exchange chromatography, Sephadex G-25 gel filtration and Tricine SDS-PAGE, the ACE was purified, which produced a ~2-kDa active band. SDS-PAGE and infrared (IR) spectroscopy indicated the proteinaceous nature of the antimicrobial compound in the ACE, and liquid chromatography electrospray ionization mass spectroscopy and de novo sequencing using an automatic, Q-TOF premier system detected a peptide with the amino acid sequence F-C-K-S-L-P-L-P-L-S-V-K (1,330.7789 Da). This novel peptide was designated as AN5-2. The antimicrobial peptide exhibited stability from pH 3 to 12 and maintained its activity after being heated to 90 °C. It also remained active after incubation with denaturants (urea, SDS and EDTA).

  4. Caracterização morfocultural, biossíntese de autoindutor e formação de biofilme por rizobactérias de hortaliças Morphocultural characterization, autoinducer biosynthesis and biofilm formation in rhizobacteria isolated from vegetable crops

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    Rachel Pinton

    2010-03-01

    Full Text Available O objetivo deste trabalho foi caracterizar e agrupar rizobactérias, isoladas de hortaliças, quanto à morfologia cultural, riqueza e diversidade e avaliar a biossíntese de autoindutores N-acil lactonas homoserinas (ALH e a capacidade de formação de biofilmes. Sete estirpes também foram avaliadas quanto ao potencial de promoção de crescimento de Brassica oleraceae var. acephala em casa de vegetação. Para verificar a produção de ALH, foram realizados ensaios com Agrobacterium tumefaciens estirpe NT1 como sistema repórter. A formação de biofilme foi avaliada pelo cultivo do isolado em meio líquido. A promoção do crescimento foi avaliada após inoculação das estirpes em plantas de couve-de-folha pela determinação da produção de massa de matérias fresca e seca. A maior diversidade morfocultural foi encontrada entre as estirpes isoladas de couve-de-folha. De um total de 112 estirpes testadas, 13% foram positivas quanto à produção de ALH; de 91 estirpes, 96% foram capazes de formar biofilmes; e de 79 estirpes, 11% foram positivas para ambas as características. Foram observadas diferenças significativas na massa de matéria seca das raízes com inoculação de 10(9 UFC mL-1 da estirpe R142, que incrementou em 55% a massa de matéria seca das raízes de couve, em relação ao controle. Não há relação entre a capacidade de formar biofilme e a detecção de ALH produzidos pelas rizobactérias avaliadas.The objective of this work was to characterize and group rhizobacteria isolated from vegetable crops for culture morphology, richness and diversity, and to evaluate the biosynthesis of N-acyl homoserine lactone (AHL autoinducers and the capacity to form biofilms. Seven strains were also assessed for their potential to promote plant growth of Brassica oleraceae var. acephala in greenhouse. To test the production of AHL, the indicator strain Agrobacterium tumefaciens NT1 was used. The formation of biofilms was evaluated by

  5. Research on the Solid State Fermentation of Jerusalem Artichoke Pomace for Producing R,R-2,3-Butanediol by Paenibacillus polymyxa ZJ-9.

    Science.gov (United States)

    Cao, Can; Zhang, Li; Gao, Jian; Xu, Hong; Xue, Feng; Huang, Weiwei; Li, Yan

    2017-06-01

    R,R-2,3-butanediol (R,R-2,3-BD) was produced by Paenibacillus polymyxa ZJ-9, which was capable of utilizing inulin without previous hydrolysis. The Jerusalem artichoke pomace (JAP) derived from the conversion of Jerusalem artichoke powder into inulin extract, which was usually used for biorefinery by submerged fermentation (SMF), was utilized in solid state fermentation (SSF) to produce R,R-2,3-BD. In this study, the fermentation parameters of SSF were optimized and determined in flasks. A novel bioreactor was designed and assembled for the laboratory scale-up of SSF, with a maximum yield of R,R-2,3-BD (67.90 g/kg (JAP)). This result is a 36.3% improvement compared with the flasks. Based on the same bath of Jerusalem artichoke powder, the total output of R,R-2,3-BD increased by 38.8% for the SSF of JAP combined with the SMF of inulin extraction. Overall, the utilization of JAP for R,R-2,3-BD production was beneficial to the comprehensive utilization of Jerusalem artichoke tuber.

  6. Control biológico de enfermedades mediante el tratamiento de semillas de cucurbitáceas con rizobacterias promotoras del crecimiento de las plantas (PGPR./Biological control of diseases by cucurbits seeds treatment with rhizobacteria plant growth promoting (PGPR.

    Directory of Open Access Journals (Sweden)

    Gilda Jiménez Montejo

    2014-01-01

    L. var. Poinsett and pumpkin (Cucurbita moschata Duch. var. INIVIT C-88 and melon (Cucumis melo L. var. Hale’s Best seeds were treated. The biological treatment showed decreasing diseases incidence and increasing root and leaves weighs and stem height, in the plant-pathogen-antagonist interactions tested; root colonization reached a range from 8,9- 8,0 and from 7,8-7, 0 log (ufc cm-1 root at 4 and 15 days after sowing. These results characterize the applied strains as Plant Growth Promoting Rhizobacteria (PGPR and make advisable the development of field trials.

  7. The role of exochitinase type A1 in the fungistatic activity of the rhizosphere bacterium Paenibacillus sp. M4

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    Jankiewicz Urszula

    2016-01-01

    Full Text Available The aim of the study was to detect the activity and characterize potentially fungistatic chitinases synthesized by rhizosphere bacteria identified as Paenibacillus sp. M4. Maximum chitinolytic activity was achieved on the fifth day of culturing bacteria in a growth medium with 1% colloidal chitin. Analysis of a zymogram uncovered the presence of four activity bands in the crude bacterial extract. The used three-stage protein purification procedure resulted in a single band of chitinase activity on the zymogram. The purified enzyme exhibited maximum activity at pH 6.5 and temperature 45oC, and thermal stability at 40oC for 4 h. In terms of substrate specificity, it is an exochitinase (chitobiose. The amino acid sequence obtained after mass spectrometry showed similarity to chitinase A1 synthesized by Bacillus circulans. The M4 isolate demonstrated the highest growth inhibiting activity against plant pathogens belonging to the genera Fusarium, Rhizoctonia and Alternaria. Fungistatic activity, although to a somewhat lesser degree, was also demonstrated by purified chitinase. The obtained results confirm the participation of the studied exochitinase in antagonism towards pathogenic molds. However, the lower fungistatic effectiveness of the chitinases points to the synergistic action of different metabolites in biocontrol by these bacteria.

  8. Bacillus aryabhattai SRB02 tolerates oxidative and nitrosative stress and promotes the growth of soybean by modulating the production of phytohormones

    Science.gov (United States)

    Kang, Sang-Mo; Shahzad, Raheem; Seo, Chang-Woo; Kim, Ah-Yeong; Lee, Sang-Uk; Oh, Kyeong Yeol; Lee, Dong Yeol; Lee, In-Jung; Yun, Byung-Wook

    2017-01-01

    Plant growth promoting rhizobacteria (PGPR) are diverse, naturally occurring bacteria that establish a close association with plant roots and promote the growth and immunity of plants. Established mechanisms involved in PGPR-mediated plant growth promotion include regulation of phytohormones, improved nutrient availability, and antagonistic effects on plant pathogens. In this study, we isolated a bacterium from the rhizospheric soil of a soybean field in Chungcheong buk-do, South Korea. Using 16S rRNA sequencing, the bacterium was identified as Bacillus aryabhattai strain SRB02. Here we show that this strain significantly promotes the growth of soybean. Gas chromatography—mass spectrometry analysis showed that SRB02 produced significant amounts of abscisic acid, indole acetic acid, cytokinin and different gibberellic acids in culture. SRB02-treated soybean plants showed significantly better heat stress tolerance than did untreated plants. These plants also produced consistent levels of ABA under heat stress and exhibited ABA-mediated stomatal closure. High levels of IAA, JA, GA12, GA4, and GA7, were recorded in SRB02-treated plants. These plants produced longer roots and shoots than those of control plants. B. aryabhattai SRB02 was found to be highly tolerant to oxidative stress induced by H2O2 and MV potentiated by high catalase (CAT) and superoxide dismutase (SOD) activities. SRB02 also tolerated high nitrosative stress induced by the nitric oxide donors GSNO and CysNO. Because of these attributes, B. aryabhattai SRB02 may prove to be a valuable resource for incorporation in biofertilizers and other soil amendments that seek to improve crop productivity. PMID:28282395

  9. Bacillus aryabhattai SRB02 tolerates oxidative and nitrosative stress and promotes the growth of soybean by modulating the production of phytohormones.

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    Yeon-Gyeong Park

    Full Text Available Plant growth promoting rhizobacteria (PGPR are diverse, naturally occurring bacteria that establish a close association with plant roots and promote the growth and immunity of plants. Established mechanisms involved in PGPR-mediated plant growth promotion include regulation of phytohormones, improved nutrient availability, and antagonistic effects on plant pathogens. In this study, we isolated a bacterium from the rhizospheric soil of a soybean field in Chungcheong buk-do, South Korea. Using 16S rRNA sequencing, the bacterium was identified as Bacillus aryabhattai strain SRB02. Here we show that this strain significantly promotes the growth of soybean. Gas chromatography-mass spectrometry analysis showed that SRB02 produced significant amounts of abscisic acid, indole acetic acid, cytokinin and different gibberellic acids in culture. SRB02-treated soybean plants showed significantly better heat stress tolerance than did untreated plants. These plants also produced consistent levels of ABA under heat stress and exhibited ABA-mediated stomatal closure. High levels of IAA, JA, GA12, GA4, and GA7, were recorded in SRB02-treated plants. These plants produced longer roots and shoots than those of control plants. B. aryabhattai SRB02 was found to be highly tolerant to oxidative stress induced by H2O2 and MV potentiated by high catalase (CAT and superoxide dismutase (SOD activities. SRB02 also tolerated high nitrosative stress induced by the nitric oxide donors GSNO and CysNO. Because of these attributes, B. aryabhattai SRB02 may prove to be a valuable resource for incorporation in biofertilizers and other soil amendments that seek to improve crop productivity.

  10. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

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    V Bianciotto

    2009-12-01

    Full Text Available Arbuscular mycorrhizal (AM fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR. We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium to AM roots and AM fungal structures. Mutants affected in extracellular polysaccharides (EPS have been tested in in vitro adhesion assays and shown to be strongly impaired in the attachment to both types of surfaces as well as to quartz fibers. Anchoring of rhizobacteria to AM fungal structures may have special ecological and biotechnological significance because it may facilitate colonisation of new rhizospheres by the bacteria, and may be an essential trait for the development of mixed inocula.

  11. Determination of plant growth promoting potential of enterobacteria isolated from the rhizosphere of maize (Zea mays L.

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    Luis H. León Mendoza

    2014-12-01

    Full Text Available The yellow maize is the third most important crop in Peru and part of the chain maize-poultry-pig, significant impact on the national economic and social activity, however, in 2011, only 40% of the corn offered corresponded to the domestic industry. Looking for alternatives to reduce the use of chemical fertilizers, have performed investigations with plant growth promoting rhizobacteria. Bacteria were isolated from the rhizosphere of maize from districts Monsefú and Reque, Lambayeque. Dilution was made into sterile saline 0.87% NaCl w/v and plated on MacConkey agar, incubating at 30°C for 48 hours. 269 pure cultures of bacteria were obtained, the biochemical reaction was investigated in agar Triple sugar iron agar Iron Lysine, agar Citrate Simons, peptone broth, red broth methyl Voges-Proskauer and nitrate broth, was identified 66% as Enterobacteriaceae of genera Pantoea (49%, Klebsiella (17%, Kluyvera (16%, Serratia (11%, Citrobacter (4% and Hafnia (3%. The native enterobacteria were quantified to 31.67 ppm of fixed nitrogen as ammonia; 54.25 ppm indole acetic acid and 4,78 ppm solubilized phosphorus, activity proteolytic and chitinolytic and antagonistic activity of Fusarium verticillioides were also determined. 16% of native enterobacteria did not affect the emergence of hard yellow maize, 77% affected positively and 7% affected negatively. In turn, none bacteria affected survival. Was demonstrated the potential plant growth promoter of enterobacteria isolated from field crops in the region of Lambayeque.

  12. Effect of bodily fluids from honey bee (Apis mellifera) larvae on growth and genome-wide transcriptional response of the causal agent of American Foulbrood disease (Paenibacillus larvae).

    Science.gov (United States)

    De Smet, Lina; De Koker, Dieter; Hawley, Alyse K; Foster, Leonard J; De Vos, Paul; de Graaf, Dirk C

    2014-01-01

    Paenibacillus larvae, the causal agent of American Foulbrood disease (AFB), affects honey bee health worldwide. The present study investigates the effect of bodily fluids from honey bee larvae on growth velocity and transcription for this Gram-positive, endospore-forming bacterium. It was observed that larval fluids accelerate the growth and lead to higher bacterial densities during stationary phase. The genome-wide transcriptional response of in vitro cultures of P. larvae to larval fluids was studied by microarray technology. Early responses of P. larvae to larval fluids are characterized by a general down-regulation of oligopeptide and sugar transporter genes, as well as by amino acid and carbohydrate metabolic genes, among others. Late responses are dominated by general down-regulation of sporulation genes and up-regulation of phage-related genes. A theoretical mechanism of carbon catabolite repression is discussed.

  13. The application of isotopic (32P and 15N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

    International Nuclear Information System (INIS)

    Barea, J.M.; Toro, M.; Azcon, R.; Orozco, M.O.; Campos, E.; Azcon, R.

    2002-01-01

    A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of 15 N and 32 P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the 15 N/ 14 N ratio in plant shoots indicate an enhancement of the N 2 fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ( 32 P/ 31 P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the test soil that was Ca deficient at neutral

  14. How to kill the honey bee larva: genomic potential and virulence mechanisms of Paenibacillus larvae.

    Directory of Open Access Journals (Sweden)

    Marvin Djukic

    Full Text Available Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB, which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity.

  15. How to kill the honey bee larva: genomic potential and virulence mechanisms of Paenibacillus larvae.

    Science.gov (United States)

    Djukic, Marvin; Brzuszkiewicz, Elzbieta; Fünfhaus, Anne; Voss, Jörn; Gollnow, Kathleen; Poppinga, Lena; Liesegang, Heiko; Garcia-Gonzalez, Eva; Genersch, Elke; Daniel, Rolf

    2014-01-01

    Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity.

  16. Characterization of Novel Fusaricidins Produced by Paenibacillus polymyxa-M1 Using MALDI-TOF Mass Spectrometry

    Science.gov (United States)

    Vater, Joachim; Niu, Ben; Dietel, Kristin; Borriss, Rainer

    2015-09-01

    Paenibacillus polymyxa-M1 is a potent producer of bioactive compounds, such as lipopeptides, polyketides, and lantibiotics of biotechnological and medical interest. Genome sequencing revealed nine gene clusters for nonribosomal biosynthesis of such agents. Here we report on the investigation of the fusaricidins, a complex of cyclic lipopeptides containing 15-guanidino-3-hydroxypentadecanoic acid (GHPD) as fatty acid component by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). More than 20 variants of these compounds were detected and characterized in detail. Mass spectrometric sequence analysis was performed by MALDI-LIFT-TOF/TOF fragment analysis. The obtained product ion spectra show a specific processing in the fatty acid part. GHPD is cleaved between the α- and ß-position yielding two fragments a and b, one bearing the end-standing guanidine group and another one comprising the residual two C-atoms of GHPD with the attached peptide moiety. The complete sequence of all fusaricidins was derived from sets of bn- and yn-ions. The fusaricidin complex can be divided into four lipopeptide families, three of them showing variations of the amino acid in position 3, Val or Ile for the first and Tyr or Phe for families 2 and 3, respectively. A collection of novel fusaricidins was detected differing from those of families 1-3 by an additional residue of 71 Da (family 4). LIFT-TOF/TOF fragment spectra of these species imply that in their peptide moiety, an Ala-residue is attached by an ester bond to the free hydroxyl group of Thr4. More than 10 novel fusaricidins were characterized mass spectrometrically.

  17. The effect of plant growth-promoting rhizobacteria on the phytoextraction of Cd and Zn by Brassica napus L.

    Science.gov (United States)

    Dąbrowska, G; Hrynkiewicz, K; Trejgell, A; Baum, C

    2017-07-03

    The test strains Bacteroidetes bacterium (Ba), Pseudomonas fluorescens (Pf) and Variovorax sp. (Va) were selected in advance for their in vitro capability for growth promotion of rapeseed in the presence of increased concentrations of Cd, Cu, Pb and Zn in the medium. In the pot experiment, the strains were used for single Ba, Pf, Va or combined Ba + Pf, Ba + Va, Pf + Va, and Ba + Pf + Va inoculation of B. napus growing in contaminated soil from alluvial deposits. The positive effect of bacterial strains on plant growth was observed in vitro, but was not confirmed in situ in the contaminated soil, where the tested strains inhibited biomass production, rather than stimulating it. However, single inoculation with Ba significantly increased the chlorophyll content and K + concentration in the leaves. The inoculation of rapeseed with Ba and Va strains was indicated to be the most promising combination for phytoextraction of Cd and Zn from contaminated soil. Combined inoculation with Pf+Va and Pf + Ba+Va significantly decreased the concentration of heavy metals in the roots of rapeseed. We conclude that suitable combinations of PGPR can control the metal uptake of B. napus, selectively increasing either metal extraction or metal stabilization in the rhizosphere and offering promising applications in soil remediation.

  18. Identification and characterization of two novel toxins expressed by the lethal honey bee pathogen Paenibacillus larvae, the causative agent of American foulbrood.

    Science.gov (United States)

    Fünfhaus, Anne; Poppinga, Lena; Genersch, Elke

    2013-11-01

    Paenibacillus larvae is a Gram-positive bacterial pathogen causing the epizootic American foulbrood in honey bee larvae. Four so-called enterobacterial repetitive intergenic consensus (ERIC) genotypes of P. larvae exist with P. larvae genotypes ERIC I and ERIC II being responsible for disease outbreaks all over the world. Very few molecular data on the pathogen, on pathogenesis or on virulence factors exist. We now identified two genomic loci in P. larvae ERIC I coding for two binary AB toxins, Plx1 and Plx2. In silico analyses revealed that Plx1 is the third member of an enigmatic family of AB toxins so far only comprising MTX1 of Lysinibacillus sphaericus and pierisin-like toxins expressed by several butterflies. Plx2 is also remarkable because the A-domain is highly similar to C3 exoenzymes, which normally are single domain proteins, while the B-domain is homologous to B-domains of C2-toxins. We constructed P. larvae mutants lacking expression of Plx1, Plx2 or both toxins and demonstrated that these toxins are important virulence factors for P. larvae ERIC I. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23) with High Potential to Control American Foulbrood.

    Science.gov (United States)

    Oliveira, Ana; Leite, Marta; Kluskens, Leon D; Santos, Sílvio B; Melo, Luís D R; Azeredo, Joana

    2015-01-01

    Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23) encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0), showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

  20. Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.

    Science.gov (United States)

    Zajicek, J.L.; Brown, L.; Brown, S.B.; Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.

    2009-01-01

    The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus thiaminolyticus over a range of pH values. The clupeids, alewife Alosa pseudoharengus and gizzard shad Dorosoma cepedianum, had very similar thiaminase I pH dependencies, with optimal activity ranges (> or = 90% of maximum activity) between pH 4.6 and 5.5. Rainbow smelt Osmerus mordax and spottail shiner Notropis hudsonius had optimal activity ranges between pH 5.5-6.6. The thiaminase I activity pH dependence profile of P. thiaminolyticus had an optimal activity range between pH 5.4 and 6.3, which was similar to the optimal range for rainbow smelt and spottail shiners. Incubation of P. thiaminolyticus extracts with extracts from bloater Coregonus hoyi (normally, bloaters have little or no detectable thiaminase I activity) did not significantly alter the pH dependence profile of P. thiaminolyticus-derived thiaminase I, such that it continued to resemble that of the rainbow smelt and spottail shiner, with an apparent optimal activity range between pH 5.7 and 6.6. These data are consistent with the hypothesis of a bacterial source for thiaminase I in the nonclupeid species of forage fish; however, the data also suggest different sources of thiaminase I enzymes in the clupeid species.

  1. A designated centre for people with disabilities operated by Cheeverstown House Limited, Dublin 6w

    LENUS (Irish Health Repository)

    Fan, Ben

    2012-06-21

    AbstractBackgroundPlant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR) and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates.ResultsBacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261) was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides.ConclusionsHere we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  2. Transcriptomic profiling of Bacillus amyloliquefaciens FZB42 in response to maize root exudates

    LENUS (Irish Health Repository)

    Fan, Ben

    2012-06-21

    AbstractBackgroundPlant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR) and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates.ResultsBacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261) was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides.ConclusionsHere we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  3. A designated centre for people with disabilities operated by Ability West, Galway

    LENUS (Irish Health Repository)

    Fan, Ben

    2012-06-21

    AbstractBackgroundPlant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR) and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates.ResultsBacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261) was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides.ConclusionsHere we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  4. Evaluation of Two Mycorrhiza Species and Nitroxin on Yield and Yield Components of Garlic (Allium sativum L.) in an Ecological Agroecosystem

    OpenAIRE

    P Rezvani Moghaddam; M. B Amiri; A Norozian; H. R Ehyaee

    2016-01-01

    Introduction Maintenance of soil fertility is one of the most important issues affecting the sustainability of food production. The application of ecological inputs such as mycorrhiza and biofertilizers are one of those approaches which are needed to maintain soil fertility Biofetilizers include different types of free living organisms that convert unavailable nutrients to available forms and enhance root development and better seed germination. Plant growth promoting rhizobacteria (PGPR)...

  5. Impacts of biostimulant products on the growth of wheat and the microbial communities of its rhizosphere under contrasted production systems

    OpenAIRE

    Nguyen, Minh; Bodson, Bernard; Colinet, Gilles; Jijakli, Haissam; Ongena, Marc; Vandenbol, Micheline; du Jardin, Patrick; Spaepen, Stijn; Delaplace, Pierre

    2014-01-01

    Plant growth-promoting rhizobacteria (PGPR) are one of the major biostimulant classes due to their ability to stimulate root growth, enhance mineral availability, and nutrient use efficiency in crops. PGPR-containing biostimulant products could therefore make agriculture more sustainable by reducing demand for chemical fertilizer and lessen their negative environmental impacts. The aim of this project is to screen PGPR strains to (1) enhance wheat fitness level (growth, photosynthesis efficie...

  6. Vertical movement of Azospirillum brasilense in soil

    International Nuclear Information System (INIS)

    Singh, Mohan; Lal, B.; Shrivastava, A.K.

    1993-01-01

    Plant growth promoting rhizobacteria like Azospirillum brasilense have considerable potential in increasing crop productivity. The success of bacterial inoculation in fields however, depends on their root colonizing ability. These bacteria, applied either through seed pelleting or directly to the soil are distributed along roots through active or passive movements. 32 P labelled A.brasilense has been used to study their movements in sandy loam soils. (author). 5 refs., 2 figs

  7. Bacteria from wheat and cucurbit plant roots metabolize PAHs and aromatic root exudates: Implications for rhizodegradation.

    Science.gov (United States)

    Ely, Cairn S; Smets, Barth F

    2017-10-03

    The chemical interaction between plants and bacteria in the root zone can lead to soil decontamination. Bacteria that degrade polycyclic aromatic hydrocarbons (PAHs) have been isolated from the rhizospheres of plant species with varied biological traits; however, it is not known what phytochemicals promote contaminant degradation. One monocot and two dicotyledon plants were grown in PAH-contaminated soil from a manufactured gas plant (MGP) site. A phytotoxicity assay confirmed greater soil decontamination in rhizospheres when compared to bulk soil controls. Bacteria were isolated from plant roots (rhizobacteria) and selected for growth on anthracene and chrysene on PAH-amended plates. Rhizosphere isolates metabolized 3- and 4-ring PAHs and PAH catabolic intermediates in liquid incubations. Aromatic root exudate compounds, namely flavonoids and simple phenols, were also substrates for isolated rhizobacteria. In particular, the phenolic compounds-morin, caffeic acid, and protocatechuic acid-appear to be linked to bacterial degradation of 3- and 4-ring PAHs in the rhizosphere.

  8. The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23 with High Potential to Control American Foulbrood.

    Directory of Open Access Journals (Sweden)

    Ana Oliveira

    Full Text Available Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23 encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0, showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

  9. Inhibitory action of essential oils against proteases activity of Paenibacillus larvae, the etiological agent of American Foulbrood disease

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, M.C.; Zalazar, L.; Fuselli, S.L.; Ponce, A.G.

    2017-07-01

    American foulbrood (AFB) is a disease affecting the larva of Apis mellifera. The etiological agent is Paenibacillus larvae, which releases metalloproteases involved in the degradation of larval tissues. Through quorum sensing (QS) mechanism, bacteria are able to activate specific genes such as virulence factors. The exoproteases regulation of P. larvae could be associated with QS. A promising mechanism of AFB control is to block QS mechanism with essential oils (EO). The aim of this study was to investigate the potential presence of QS signals in the regulation of P. larvae proteases and the effect of seven EOs on the exoproteases activity of P. larvae. From growth curves and evaluation of the presence of proteases by milk agar plates assay, it was observed protease activity during the late exponential phase of growth. Early production of protease activity (15 hours earlier than control) was observed when a low density culture was incubated with late exponential spent medium (SM) suggesting the presence of factor(s) inducing this activity. SM was obtained by the ultrafiltration of P. larvae cultures on late growth phase and was free of proteases. Proteolytic activity was quantified on P. larvae cultures in presence of sublethal concentration of EO by azocasein method. The EOs, except S. chilensis EO, reduced significantly protease activity (more than 50%). We report for the first time evidence on the possible role of QS on P. larvae and the antiproteolytic activity of EOs (except for S. chilensis) on exoproteases, an interesting therapeutic strategy to control AFB.

  10. A single amino acid mutation in Spo0A results in sporulation deficiency of Paenibacillus polymyxa SC2.

    Science.gov (United States)

    Hou, Xiaoyang; Yu, Xiaoning; Du, Binghai; Liu, Kai; Yao, Liangtong; Zhang, Sicheng; Selin, C; Fernando, W G D; Wang, Chengqiang; Ding, Yanqin

    2016-01-01

    Sporulating bacteria such as Bacillus subtilis and Paenibacillus polymyxa exhibit sporulation deficiencies during their lifetime in a laboratory environment. In this study, spontaneous mutants SC2-M1 and SC2-M2, of P. polymyxa SC2 lost the ability to form endospores. A global genetic and transcriptomic analysis of wild-type SC2 and spontaneous mutants was carried out. Genome resequencing analysis revealed 14 variants in the genome of SC2-M1, including three insertions and deletions (indels), 10 single nucleotide variations (SNVs) and one intrachromosomal translocation (ITX). There were nine variants in the genome of SC2-M2, including two indels and seven SNVs. Transcriptomic analysis revealed that 266 and 272 genes showed significant differences in expression in SC2-M1 and SC2-M2, respectively, compared with the wild-type SC2. Besides sporulation-related genes, genes related to exopolysaccharide biosynthesis (eps), antibiotic (fusaricidin) synthesis, motility (flgB) and other functions were also affected in these mutants. In SC2-M2, reversion of spo0A resulted in the complete recovery of sporulation. This is the first global analysis of mutations related to sporulation deficiency in P. polymyxa. Our results demonstrate that a SNV within spo0A caused the sporulation deficiency of SC2-M2 and provide strong evidence that an arginine residue at position 211 is essential for the function of Spo0A. Copyright © 2016 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.

  11. Inhibitory action of essential oils against proteases activity of Paenibacillus larvae, the etiological agent of American Foulbrood disease

    International Nuclear Information System (INIS)

    Pellegrini, M.C.; Zalazar, L.; Fuselli, S.L.; Ponce, A.G.

    2017-01-01

    American foulbrood (AFB) is a disease affecting the larva of Apis mellifera. The etiological agent is Paenibacillus larvae, which releases metalloproteases involved in the degradation of larval tissues. Through quorum sensing (QS) mechanism, bacteria are able to activate specific genes such as virulence factors. The exoproteases regulation of P. larvae could be associated with QS. A promising mechanism of AFB control is to block QS mechanism with essential oils (EO). The aim of this study was to investigate the potential presence of QS signals in the regulation of P. larvae proteases and the effect of seven EOs on the exoproteases activity of P. larvae. From growth curves and evaluation of the presence of proteases by milk agar plates assay, it was observed protease activity during the late exponential phase of growth. Early production of protease activity (15 hours earlier than control) was observed when a low density culture was incubated with late exponential spent medium (SM) suggesting the presence of factor(s) inducing this activity. SM was obtained by the ultrafiltration of P. larvae cultures on late growth phase and was free of proteases. Proteolytic activity was quantified on P. larvae cultures in presence of sublethal concentration of EO by azocasein method. The EOs, except S. chilensis EO, reduced significantly protease activity (more than 50%). We report for the first time evidence on the possible role of QS on P. larvae and the antiproteolytic activity of EOs (except for S. chilensis) on exoproteases, an interesting therapeutic strategy to control AFB.

  12. Inhibitory action of essential oils against proteases activity of Paenibacillus larvae, the etiological agent of American Foulbrood disease

    Directory of Open Access Journals (Sweden)

    María C. Pellegrini

    2018-02-01

    Full Text Available American foulbrood (AFB is a disease affecting the larva of Apis mellifera. The etiological agent is Paenibacillus larvae, which releases metalloproteases involved in the degradation of larval tissues. Through quorum sensing (QS mechanism, bacteria are able to activate specific genes such as virulence factors. The exoproteases regulation of P. larvae could be associated with QS. A promising mechanism of AFB control is to block QS mechanism with essential oils (EO. The aim of this study was to investigate the potential presence of QS signals in the regulation of P. larvae proteases and the effect of seven EOs on the exoproteases activity of P. larvae. From growth curves and evaluation of the presence of proteases by milk agar plates assay, it was observed protease activity during the late exponential phase of growth. Early production of protease activity (15 hours earlier than control was observed when a low density culture was incubated with late exponential spent medium (SM suggesting the presence of factor(s inducing this activity. SM was obtained by the ultrafiltration of P. larvae cultures on late growth phase and was free of proteases. Proteolytic activity was quantified on P. larvae cultures in presence of sublethal concentration of EO by azocasein method. The EOs, except S. chilensis EO, reduced significantly protease activity (more than 50%. We report for the first time evidence on the possible role of QS on P. larvae and the antiproteolytic activity of EOs (except for S. chilensis on exoproteases, an interesting therapeutic strategy to control AFB.

  13. Control potential of Meloidogyne javanica and Ditylenchus spp. using fluorescent Pseudomonas and Bacillus spp.

    Directory of Open Access Journals (Sweden)

    Marcielly F. Turatto

    Full Text Available ABSTRACT Plant Growth Promoting Rhizobacteria (PGPR have different mechanisms of action in the development of plants, such as growth promotion, production of phytohormones and antibiotic substances and changes in root exudates. These help to control plant diseases. In order to evaluate the potential of microorganisms in the control of Meloidogyne javanica and Ditylenchus spp., five rhizobacteria isolated from rhizosphere of garlic cultivated in the Curitibanos (SC region were tested. Hatching chambers were set on Petri dishes, in which were added 10 mL of bacterial suspension and 1 mL of M. javanica eggs suspension, at the rate of 4500, on the filter paper of each chamber. The same procedure was performed with 300 juvenile Ditylenchus spp. The experimental design was completely randomized, with four replications. The evaluations were performed every 72 h for nine days. The antagonized population of nematodes was determined in Peters counting chamber, determining the percentage hatching (for M. javanica and motility (for Ditylenchus spp. Isolates CBSAL02 and CBSAL05 significantly reduced the hatching of M. javanica eggs (74% and 54.77%, respectively and the motility of Ditylenchus spp. (55.19% and 53.53%, respectively in vitro. Isolates were identified as belonging to the genera Pseudomonas (CBSAL05 and Bacillus (CBSAL02.

  14. Testing of inhibition activity of essential oils against Paenibacillus larvae – the causative agent of American foulbrood

    Directory of Open Access Journals (Sweden)

    Katarína Kuzyšinová

    2014-01-01

    Full Text Available American foulbrood is a dangerous world-wide spread disease of honey bees caused by the Paenibacillus larvae bacterium. Antibiotic treatments are less effective and leave residues in bee products. It is therefore necessary to find an alternative, especially using natural ingredients such as plant essential oils, probiotics, fatty or organic acids. Two strains of P. larvae were used for this study: CCM 4488, a strain from the Czech collection of micro-organisms and a Slovak field strain which was isolated from infected bee combs and characterized on the basis of biochemical properties. Plant essential oils of sage (Salvia officinalis, anise (Pimpinella anisum, oregano (Origanum vulgare, caraway (Carum carvi, thyme (Thymus vulgaris, rosemary (Rosmarinum officinalis, clove (Syzygium aromaticum, camomile (Chamomilla recutita and fennel (Foeniculum vulgare were used for the testing of the inhibitory activity against P. larvae. Essential oils at amounts of 5 µl and 10 µl were applied to sterile discs on MYPGP agar; inhibition zone diameters were measured after 24-h incubation at 37 °C. The strongest inhibitory activity against both P. larvae strains was noted in case of the essential oils from oregano, thyme and clove; essential oils from camomile, rosemary and fennel showed no or weak antibacterial activity. Medium strong inhibition activity was recorded in case of previously untested essential oil from Carum carvi. There was a difference in sensitivity of both tested strains to essential oils. Our study confirmed that some essential oils can be used in the prevention of American foulbrood but further experiments aimed at their influence on physiological intestinal microflora of honey bees must be performed.

  15. Regional distribution of Paenibacillus larvae subspecies larvae, the causative organism of American foulbrood, in honey bee colonies of the Western United States.

    Science.gov (United States)

    Eischen, Frank A; Graham, R Henry; Cox, Robert

    2005-08-01

    We examined honey bee, Apis mellifera L., colonies pollinating almonds in California during February 2003 for Paenibacillus larvae subsp. Larvae, the causative organism of the virulent brood disease American foulbrood. Colonies originating from the Rocky Mountain area and California had significantly higher numbers (P bees, respectively) than colonies from the upper Midwest (1.28). Colonies from the northwestern, central, and southwestern United States had intermediate CFU or bacterial colony levels. Operations positive for P. larvae larvae were relatively uniform at approximately 70-80%, and no regional significant differences were found. Percentages of colonies with high CFUs (> or = 400 per 30 bees) differed significantly, with those from the Rocky Mountain region having 8.73% compared with those of the upper Midwest with 0%. The significance of CFU levels was evaluated by inoculating healthy colonies with diseased immatures and sampling adult bees. The number of CFUs detected per diseased immature was conservatively estimated to be approximately 399 CFUs per 30 adult bees. We defined this spore level as 1 disease equivalent. Based on this, 3.86% colonies in our survey had 1 or more disease equivalent number of P. larvae larvae CFUs. Operations with high P. larvae larvae spore levels in their colonies will likely observe American foulbrood if prophylaxis is not practiced diligently.

  16. Effect of plant growth-promoting rhizobacteria (PGPRs) on plant growth, yield, and quality of tomato (Lycopersicon esculentum Mill.) under simulated seawater irrigation.

    Science.gov (United States)

    Shen, Min; Jun Kang, Yi; Li Wang, Huan; Sheng Zhang, Xiang; Xin Zhao, Qing

    2012-01-01

    To determine the effects of three PGPRs on plant growth, yield, and quality of tomato under simulated seawater irrigation, a two consecutive seasons' field experiment was conducted in Yancheng Teachers University plot from April to June and August to October, 2011. The results showed that Erwinia persicinus RA2 containing ACC deaminase exhibited the best ability compared with Bacillus pumilus WP8 and Pseudomonas putida RBP1 which had no ACC deaminase activity to enhance marketable yields of fresh and dried fruits in tomato under simulated seawater irrigation especially under HS condition. B. pumilus WP8 had significant effects on improving tomato fruit quality under the conditions of irrigating with 1.0% NaCl solution (MS) and with 2.0% NaCl solution (HS). Na(+) contents were generally accumulated much more in tomato plant mid-shoot leaves than in fruits whatever the salt concentration. More sodium accumulation in leaves of E. persicinus RA2 and B. pumilus WP8 treatments under HS condition were found than in control. E. persicinus RA2 and B. pumilus WP8 can promote tomato growth, improve fruit quality more firmly than P. putida RBP1 during two consecutive seasons. Our study suggested that E. persicinus RA2 and B. pumilus WP8 are considered to be promising PGPR strains which are suited for application in salt marsh planting, ACC deaminase activity was not unique index on screening for PGPRs with the aim of salt stress tolerance, and plant growth promoting activities may be relevant to different growth indices and different stress conditions.

  17. Precursor Amino Acids Inhibit Polymyxin E Biosynthesis in Paenibacillus polymyxa, Probably by Affecting the Expression of Polymyxin E Biosynthesis-Associated Genes

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    Zhiliang Yu

    2015-01-01

    Full Text Available Polymyxin E belongs to cationic polypeptide antibiotic bearing four types of direct precursor amino acids including L-2,4-diaminobutyric acid (L-Dab, L-Leu, D-Leu, and L-Thr. The objective of this study is to evaluate the effect of addition of precursor amino acids during fermentation on polymyxin E biosynthesis in Paenibacillus polymyxa. The results showed that, after 35 h fermentation, addition of direct precursor amino acids to certain concentration significantly inhibited polymyxin E production and affected the expression of genes involved in its biosynthesis. L-Dab repressed the expression of polymyxin synthetase genes pmxA and pmxE, as well as 2,4-diaminobutyrate aminotransferase gene ectB; both L-Leu and D-Leu repressed the pmxA expression. In addition, L-Thr affected the expression of not only pmxA, but also regulatory genes spo0A and abrB. As L-Dab precursor, L-Asp repressed the expression of ectB, pmxA, and pmxE. Moreover, it affected the expression of spo0A and abrB. In contrast, L-Phe, a nonprecursor amino acid, had no obvious effect on polymyxin E biosynthesis and those biosynthesis-related genes expression. Taken together, our data demonstrated that addition of precursor amino acids during fermentation will inhibit polymyxin E production probably by affecting the expression of its biosynthesis-related genes.

  18. Induksi Ketahanan terhadap Penyakit Hawar Daun Bakteri pada Tanaman Padi di Lapangan Menggunakan Rizobakteri Indigenos

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    Andi Khaeruni

    2014-03-01

    Full Text Available ABSTRACT Induced resistance to bacterial leaf blight disease in rice field by indigenous rhizobacteria.  Bacterial leaf blight is the most important disease on paddy at Southeast Sulawesi. Utilization of biological agents that induce plant resistance is an alternative tool to control bacterial leaf blight disease on paddy. The aim of  the experiment was obtain rhizobacteria that were able to stimulate the growth of paddy plants as well induce plant resistance towards bacterial leaf blight in the field. All experiment units were arranged with a factorial design in a randomized complete block design. The first factor was the rhizobacteria isolates, consisting 4 treatments, i.e: without rhizobacteria (R0, isolate P11a (R1, isolate PKLK5 (IR2, and  mixture P11a and PKLK5 (R3, the second factor is paddy varieties, (V1: IR64 variety, (V2: Cisantana variety. The pathogen was inoculated on leaf when 45 day after crop.  Weekly observation of disease severity, vegetative plant growth (leaf and stem numbers, and yield were conducted. The results showed that the 10 isolates of rhizobacteria tested were able to induce plant resistance toward bacterial leaf blight, stimulated vegetative growth as well as increased yield of paddy plant. Rhizobacteria application could increase the resistance of paddy toward Xanthomonas oryzae pv. oryzae. The application rhizobacteria could increase the vegetative plant growth, application  mixture P11a and PKLK5 isolates showed higher resistance than single application in terms of plant growth and yield, both IR64 and Cisantana varietes

  19. The innate immune and systemic response in honey bees to a bacterial pathogen, Paenibacillus larvae

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    Foster Leonard J

    2009-08-01

    Full Text Available Abstract Background There is a major paradox in our understanding of honey bee immunity: the high population density in a bee colony implies a high rate of disease transmission among individuals, yet bees are predicted to express only two-thirds as many immunity genes as solitary insects, e.g., mosquito or fruit fly. This suggests that the immune response in bees is subdued in favor of social immunity, yet some specific immune factors are up-regulated in response to infection. To explore the response to infection more broadly, we employ mass spectrometry-based proteomics in a quantitative analysis of honey bee larvae infected with the bacterium Paenibacillus larvae. Newly-eclosed bee larvae, in the second stage of their life cycle, are susceptible to this infection, but become progressively more resistant with age. We used this host-pathogen system to probe not only the role of the immune system in responding to a highly evolved infection, but also what other mechanisms might be employed in response to infection. Results Using quantitative proteomics, we compared the hemolymph (insect blood of five-day old healthy and infected honey bee larvae and found a strong up-regulation of some metabolic enzymes and chaperones, while royal jelly (food and energy storage proteins were down-regulated. We also observed increased levels of the immune factors prophenoloxidase (proPO, lysozyme and the antimicrobial peptide hymenoptaecin. Furthermore, mass spectrometry evidence suggests that healthy larvae have significant levels of catalytically inactive proPO in the hemolymph that is proteolytically activated upon infection. Phenoloxidase (PO enzyme activity was undetectable in one or two-day-old larvae and increased dramatically thereafter, paralleling very closely the age-related ability of larvae to resist infection. Conclusion We propose a model for the host response to infection where energy stores and metabolic enzymes are regulated in concert with direct

  20. The application of isotopic ({sup 32}P and {sup 15}N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

    Energy Technology Data Exchange (ETDEWEB)

    Barea, J.M. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)]. E-mail: jmbarea@eez.csic.es; Toro, M.; Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain); Orozco, M.O. [Instituto de Sistematica y Ecologia, Academia Cubana de Ciencias, Habana (Cuba); Campos, E. [Departamento de Ciencias de la Tierra y Quimica Ambiental Estacion Experimental del Zaidin (CSIC), Granada (Spain); Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)

    2002-05-15

    A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of {sup 15}N and {sup 32}P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the {sup 15}N/{sup 14}N ratio in plant shoots indicate an enhancement of the N{sub 2} fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ({sup 32}P/{sup 31}P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the

  1. Getting the ecology into interactions between plants and the plant growth-promoting bacterium Pseudomonas fluorescens.

    Science.gov (United States)

    Hol, W H Gera; Bezemer, T Martijn; Biere, Arjen

    2013-01-01

    Plant growth-promoting rhizobacteria (PGPR) are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas fluorescens) on plants through induced plant defense. This model organism has provided much understanding of the underlying molecular mechanisms of PGPR-induced plant defense. However, this knowledge can only be appreciated at full value once we know to what extent these mechanisms also occur under more realistic, species-diverse conditions as are occurring in the plant rhizosphere. To provide the necessary ecological context, we review the literature to compare the effect of P. fluorescens on induced plant defense when it is present as a single species or in combination with other soil dwelling species. Specifically, we discuss combinations with other plant mutualists (bacterial or fungal), plant pathogens (bacterial or fungal), bacterivores (nematode or protozoa), and decomposers. Synergistic interactions between P. fluorescens and other plant mutualists are much more commonly reported than antagonistic interactions. Recent developments have enabled screenings of P. fluorescens genomes for defense traits and this could help with selection of strains with likely positive interactions on biocontrol. However, studies that examine the effects of multiple herbivores, pathogens, or herbivores and pathogens together on the effectiveness of PGPR to induce plant defenses are underrepresented and we are not aware of any study that has examined interactions between P. fluorescens and bacterivores or decomposers. As co-occurring soil organisms can enhance but also reduce the effectiveness of PGPR, a better understanding of the biotic factors modulating P. fluorescens-plant interactions will improve the effectiveness of introducing P. fluorescens to enhance plant production and defense.

  2. Swarming and complex pattern formation in Paenibacillus vortex studied by imaging and tracking cells

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    Jacob Eshel

    2008-02-01

    Full Text Available Abstract Background Swarming motility allows microorganisms to move rapidly over surfaces. The Gram-positive bacterium Paenibacillus vortex exhibits advanced cooperative motility on agar plates resulting in intricate colonial patterns with geometries that are highly sensitive to the environment. The cellular mechanisms that underpin the complex multicellular organization of such a simple organism are not well understood. Results Swarming by P. vortex was studied by real-time light microscopy, by in situ scanning electron microscopy and by tracking the spread of antibiotic-resistant cells within antibiotic-sensitive colonies. When swarming, P. vortex was found to be peritrichously flagellated. Swarming by the curved cells of P. vortex occurred on an extremely wide range of media and agar concentrations (0.3 to 2.2% w/v. At high agar concentrations (> 1% w/v rotating colonies formed that could be detached from the main mass of cells by withdrawal of cells into the latter. On lower percentage agars, cells moved in an extended network composed of interconnected "snakes" with short-term collision avoidance and sensitivity to extracts from swarming cells. P. vortex formed single Petri dish-wide "supercolonies" with a colony-wide exchange of motile cells. Swarming cells were coupled by rapidly forming, reversible and non-rigid connections to form a loose raft, apparently connected via flagella. Inhibitors of swarming (p-Nitrophenylglycerol and Congo Red were identified. Mitomycin C was used to trigger filamentation without inhibiting growth or swarming; this facilitated dissection of the detail of swarming. Mitomycin C treatment resulted in malcoordinated swarming and abortive side branch formation and a strong tendency by a subpopulation of the cells to form minimal rotating aggregates of only a few cells. Conclusion P. vortex creates complex macroscopic colonies within which there is considerable reflux and movement and interaction of cells. Cell

  3. Inactivation of Escherichia coli O157:H7 on stainless steel upon exposure to Paenibacillus polymyxa biofilms.

    Science.gov (United States)

    Kim, Seonhwa; Bang, Jihyun; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon

    2013-11-01

    We investigated the potential use of biofilm formed by a competitive-exclusion (CE) microorganism to inactivate Escherichia coli O157:H7 on a stainless steel surface. Five microorganisms showing inhibitory activities against E. coli O157:H7 were isolated from vegetable seeds and sprouts. The microorganism with the greatest antimicrobial activity was identified as Paenibacillus polymyxa (strain T5). In tryptic soy broth (TSB), strain T5 reached a higher population at 25 °C than at 12 or 37 °C without losing inhibitory activity against E. coli O157:H7. When P. polymyxa (6 log CFU/mL) was co-cultured with E. coli O157:H7 (2, 3, 4, or 5 log CFU/mL) in TSB at 25 °C, the number of E. coli O157:H7 decreased significantly within 24h. P. polymyxa formed a biofilm on stainless steel coupons (SSCs) in TSB at 25 °C within 24h, and cells in biofilms, compared to attached cells without biofilm formation, showed significantly increased resistance to a dry environment (43% relative humidity [RH]). With the exception of an inoculum of 4 log CFU/coupon at 100% RH, upon exposure to biofilm formed by P. polymyxa on SSCs, populations of E. coli O157:H7 (2, 4, or 6 log CFU/coupon) were significantly reduced within 48 h. Most notably, when E. coli O157:H7 at 2 log CFU/coupon was applied to SSCs on which P. polymyxa biofilm had formed, it was inactivated within 1h, regardless of RH. These results will be useful when developing strategies using biofilms produced by competitive exclusion microorganisms to inactivate foodborne pathogens in food processing environments. © 2013.

  4. Biological effects of paenilamicin, a secondary metabolite antibiotic produced by the honey bee pathogenic bacterium Paenibacillus larvae.

    Science.gov (United States)

    Garcia-Gonzalez, Eva; Müller, Sebastian; Hertlein, Gillian; Heid, Nina; Süssmuth, Roderich D; Genersch, Elke

    2014-10-01

    Paenibacillus larvae is the etiological agent of American Foulbrood (AFB) a world-wide distributed devastating disease of the honey bee brood. Previous comparative genome analysis and more recently, the elucidation of the bacterial genome, provided evidence that this bacterium harbors putative functional nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) and therefore, might produce nonribosomal peptides (NRPs) and polyketides (PKs). Such biosynthesis products have been shown to display a wide-range of biological activities such as antibacterial, antifungal or cytotoxic activity. Herein we present an in silico analysis of the first NRPS/PKS hybrid of P. larvae and we show the involvement of this cluster in the production of a compound named paenilamicin (Pam). For the characterization of its in vitro and in vivo bioactivity, a knock-out mutant strain lacking the production of Pam was constructed and subsequently compared to wild-type species. This led to the identification of Pam by mass spectrometry. Purified Pam-fractions showed not only antibacterial but also antifungal and cytotoxic activities. The latter suggested a direct effect of Pam on honey bee larval death which could, however, not be corroborated in laboratory infection assays. Bee larvae infected with the non-producing Pam strain showed no decrease in larval mortality, but a delay in the onset of larval death. We propose that Pam, although not essential for larval mortality, is a virulence factor of P. larvae influencing the time course of disease. These findings are not only of significance in elucidating and understanding host-pathogen interactions but also within the context of the quest for new compounds with antibiotic activity for drug development. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  5. Antimicrobial activity of plant extracts against the honeybee pathogens, Paenibacillus larvae and Ascosphaera apis and their topical toxicity to Apis mellifera adults.

    Science.gov (United States)

    Chaimanee, V; Thongtue, U; Sornmai, N; Songsri, S; Pettis, J S

    2017-11-01

    To explore alternative nonchemical control measures against two honeybee pathogens, Paenibacillus larvae and Ascosphaera apis, 37 plant species were screened for antimicrobial activity. The activity of selected plant extracts was screened using an in vitro disc diffusion assay and the minimal inhibitory concentration (MIC) was determined by the broth microdilution method. The results showed that 36 plant extracts had some antibacterial activity on P. larvae by disc diffusion assay. Chromolaena odorata showed the greatest antibacterial activity against P. larvae (MIC 16-64 μg ml -1 ). Of the 37 tested plants, only seven species, Amomum krervanh, Allium sativum, Cinnamomum sp., Piper betle, Piper ribesioides, Piper sarmentosum and Syzygium aromaticum had inhibitory effects on A. apis (MICs of 32-64 μg ml -1 ). The results demonstrated that promising plant extracts were not toxic to adult bees at the concentrations used in this study. The results demonstrate the potential antimicrobial activity of natural products against honeybee diseases caused by P. larvae and A. apis. Chromolaena odorata in particular showed high bioactivity against P. larvae. Further study is recommended to develop these nonchemical treatments against American foulbrood and chalkbrood in honeybees. This work proposes new natural products for the control of American foulbrood and chalkbrood in honeybees. © 2017 The Society for Applied Microbiology.

  6. Chemical Composition, Antimicrobial Activity, and Mode of Action of Essential Oils against Paenibacillus larvae, Etiological Agent of American Foulbrood on Apis mellifera.

    Science.gov (United States)

    Pellegrini, María C; Alonso-Salces, Rosa M; Umpierrez, María L; Rossini, Carmen; Fuselli, Sandra R

    2017-04-01

    This study aimed to characterize the chemical composition of Aloysia polystachia, Acantholippia seriphioides, Schinus molle, Solidago chilensis, Lippia turbinata, Minthostachys mollis, Buddleja globosa, and Baccharis latifolia essential oils (EOs), and to evaluate their antibacterial activities and their capacity to provoke membrane disruption in Paenibacillus larvae, the bacteria that causes the American Foulbrood (AFB) disease on honey bee larvae. The relationship between the composition of the EOs and these activities on P. larvae was also analyzed. Monoterpenes were the most abundant compounds in all EOs. All EOs showed antimicrobial activity against P. larvae and disrupted the cell wall and cytoplasmic membrane of P. larvae provoking the leakage of cytoplasmic constituents (with the exception of B. latifolia EO). While, the EOs' antimicrobial activity was correlated most strongly to the content of pulegone, carvone, (Z)-β-ocimene, δ-cadinene, camphene, terpinen-4-ol, elemol, β-pinene, β-elemene, γ-cadinene, α-terpineol, and bornyl acetate; the volatiles that better explained the membrane disruption were carvone, limonene, cis-carvone oxide, pentadecane, trans-carvyl acetate, trans-carvone oxide, trans-limonene oxide, artemisia ketone, trans-carveol, thymol, and γ-terpinene (positively correlated) and biciclogermacrene, δ-2-carene, verbenol, α-pinene, and α-thujene (negatively correlated). The studied EOs are proposed as natural alternative means of control for the AFB disease. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  7. EVALUATION OF PHYTOTOXIC EFFECT OF DELETERIOUS RHIZOBACTERIA ON THE ROOT GROWTH OF AXONOPUS AFFINIS (CHASE AND LENS ESCULENTA (MOENCH

    Directory of Open Access Journals (Sweden)

    X.J Pacheco-Hernández

    2015-11-01

    Full Text Available Las malezas ocasionan una gran pérdida en las tierras agrícolas y comúnmente, las medidas de manejo y contención de estas especies se dan con la aplicación de herbicidas, sin embargo; en años recientes se ha presentado un interés en establecer mecanismos de biocontrol seguros, con el empleo de bacterias inhibidoras del crecimiento conocidas como rizobacterias deletéreas (Deleterious rhizobacteria: DRBque se consideran generalmente como no parasíticas, y causan, de manera sutil, efectos deletéreos a través de la producción de metabolitos dañinos a las plantas. El presente trabajo tuvo como objetivo caracterizar la producción de ácido cianhídrico de pseudomonas rizobacterianas de malezas de un cultivo de alfalfa (Medicago sativa L. y evaluar el efecto fitotóxico de éstas sobre el crecimiento radical de plántulas de Axonopus affinis (Chase y Lens esculenta (Moench. De acuerdo con los resultados obtenidos con relación a la evidencia de que los aislados de pseudomonadas son rizobacterias cianogénicas y de su efecto fitotóxico medido sobre las especies vegetales bajo estudio; se sugieren a éstas como posibles agentes de biocontrol con pastos que sean considerados malezas; ya que en general se observó que inhiben su crecimiento radical; sin embargo, un enfoque particular lo tiene la rizobacteria Pseudomonas sp. A52, la cual presentó no solamente actividad como una DRB sino también como una rizobacteria promotora del crecimiento vegetal; lo que la hace más importante de analizar en cuanto a su potencial y espectro de acción; tanto para malezas monocotiledóneas como para dicotiledóneas, recomendable como un posible agente de biocontrol con actividad múltiple.

  8. In vitro antibacterial effect of exotic plants essential oils on the honeybee pathogen Paenibacillus larvae, causal agent of American foul brood

    Energy Technology Data Exchange (ETDEWEB)

    Fuselli, S. R.; Garcia de la Rosa, S. B.; Eguaras, M. J.; Fritz, R.

    2010-07-01

    Chemical composition and antimicrobial activity of exotic plants essential oils to potentially control Paenibacillus larvae, the causal agent of American foul brood disease (AFB) were determined. AFB represents one of the main plagues that affect the colonies of honeybees Apis mellifera L. with high negative impact on beekeepers worldwide. Essential oils tested were niaouli (Melaleuca viridiflora) and tea tree (Melaleuca alternifolia) from Myrtaceae, and citronella grass (Cymbopogon nardus) and palmarosa (Cymbopogon martinii) from Gramineae. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae was determined by the broth micro dilution method. In vitro assays of M. viridiflora and C. nardus oils showed the inhibition of the bacterial strains at the lowest concentrations tested, with minimal inhibitory concentration (MIC) mean value about 320 mg L{sup -}1 for both oils, respectively. This property could be attributed to the kind and percentage of the components of the oils. Terpinen-4-ol (29.09%), {alpha}-pinene (21.63%) and limonene (17.4%) were predominant in M. viridiflora, while limonene (24.74%), citronelal (24.61%) and geraniol (15.79%) were the bulk of C. nardus. The use of these essential oils contributes to the screening of alternative natural compounds to control AFB in the apiaries; toxicological risks and other undesirable effects would be avoided as resistance factors, developed by the indiscriminate use of antibiotics. (Author) 40 refs.

  9. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean,

  10. Medicago truncatula Gaertn. as a model for understanding the mechanism of growth promotion by bacteria from rhizosphere and nodules of alfalfa.

    Science.gov (United States)

    Kisiel, Anna; Kępczyńska, Ewa

    2016-05-01

    in this study also increased the IAA level in the leaves upon inoculation. Moreover, several other factors such as mobilization of phosphorus and zinc to make them available to plants, iron sequestration by siderophore production and the ability to ammonia production also contributed substantially to the phytostimulatory biofertilizing potential of isolated strains. There is, thus, evidence that Medicago truncatula growth promotion by rhizobacteria involves more than one mechanism.

  11. Selenite resistant rhizobacteria stimulate SeO(3) (2-) phytoextraction by Brassica juncea in bioaugmented water-filtering artificial beds.

    Science.gov (United States)

    Lampis, Silvia; Ferrari, Anita; Cunha-Queda, A Cristina F; Alvarenga, Paula; Di Gregorio, Simona; Vallini, Giovanni

    2009-09-01

    Selenium is a trace metalloid of global environmental concern. The boundary among its essentiality, deficiency, and toxicity is narrow and mainly depends on the chemical forms and concentrations in which this element occurs. Different plant species-including Brassica juncea-have been shown to play a significant role in Se removal from soil as well as water bodies. Furthermore, the interactions between such plants, showing natural capabilities of metal uptake and their rhizospheric microbial communities, might be exploited to increase both Se scavenging and vegetable biomass production in order to improve the whole phytoextraction efficiency. The aim of the present study was to evaluate the capability of selenite removal of B. juncea grown in hydroponic conditions on artificially spiked effluents. To optimize phytoextraction efficiency, interactions between B. juncea and rhizobacteria were designedly elicited. Firstly, B. juncea was grown on water-filtering agriperlite beds in the presence of three different selenite concentrations, namely, 0.2, 1.0, and 2.0 mM. Plant growth was measured after 3 and 6 weeks of incubation in order to establish the selenite concentration at which the best plant biomass production could be obtained. Afterwards, water-filtering agriperlite beds were inoculated either with a selenium-acclimated microbial community deriving from the rhizosphere of B. juncea grown, erstwhile, in a selenite-amended soil or with axenic cultures of two bacterial strains, vicelike Bacillus mycoides SeITE01 and Stenotrophomonas maltophilia SeITE02, previously isolated and described for their high resistance to selenite. These latter were seeded separately or as a dual consortium. Selenite was amended at a final concentration of 1.0 mM. Total Se content in plant tissues (both shoots and roots), plant biomass production, and persistence of bioaugmented microbial inocula during the experimental time were monitored. Moreover, parameters such as bioconcentration

  12. Inoculation of Brassica oxyrrhina with plant growth promoting bacteria for the improvement of heavy metal phytoremediation under drought conditions.

    Science.gov (United States)

    Ma, Ying; Rajkumar, Mani; Zhang, Chang; Freitas, Helena

    2016-12-15

    The aim of this study was to investigate the effects of drought resistant serpentine rhizobacteria on plant growth and metal uptake by Brassica oxyrrhina under drought stress (DS) condition. Two drought resistant serpentine rhizobacterial strains namely Pseudomonas libanensis TR1 and Pseudomonas reactans Ph3R3 were selected based on their ability to stimulate seedling growth in roll towel assay. Further assessment on plant growth promoting (PGP) parameters revealed their ability to produce indole-3-acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. Moreover, both strains exhibited high resistance to various heavy metals, antibiotics, salinity and extreme temperature. Inoculation of TR1 and Ph3R3 significantly increased plant growth, leaf relative water and pigment content of B. oxyrrhina, whereas decreased concentrations of proline and malondialdehyde in leaves under metal stress in the absence and presence of DS. Regardless of soil water conditions, TR1 and Ph3R3 greatly improved organ metal concentrations, translocation and bioconcentration factors of Cu and Zn. The successful colonization and metabolic activities of P. libanensis TR1 and P. reactans Ph3R3 represented positive effects on plant development and metal phytoremediation under DS. These results indicate that these strains could be used as bio-inoculants for the improvement of phytoremediation of metal polluted soils under semiarid conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Effects of the plant growth-promoting bacterium Burkholderia phytofirmans PsJN throughout the life cycle of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    María Josefina Poupin

    Full Text Available Plant growth-promoting rhizobacteria (PGPR induce positive effects in plants, such as increased growth or reduced stress susceptibility. The mechanisms behind PGPR/plant interaction are poorly understood, as most studies have described short-term responses on plants and only a few studies have analyzed plant molecular responses under PGPR colonization. Here, we studied the effects of the PGPR bacterial model Burkholderiaphytofirmans PsJN on the whole life cycle of Arabidopsis thaliana plants. We reported that at different plant developmental points, strain PsJN can be found in the rhizosphere and also colonizing their internal tissues. In early ontogeny, strain PsJN increased several growth parameters and accelerated growth rate of the plants. Also, an Arabidopsis transcriptome analysis revealed that 408 genes showed differential expression in PsJN-inoculated plants; some of these genes are involved in stress response and hormone pathways. Specifically, genes implicated in auxin and gibberellin pathways were induced. Quantitative transcriptional analyses of selected genes in different developmental stages revealed that the beginning of these changes could be evidenced early in development, especially among the down-regulated genes. The inoculation with heat-killed bacteria provoked a more severe transcriptional response in plants, but was not able to induce plant growth-promotion. Later in ontogeny, the growth rates of inoculated plants decreased with respect to the non-inoculated group and, interestingly, the inoculation accelerated the flowering time and the appearance of senescence signs in plants; these modifications correlate with the early up-regulation of flowering control genes. Then, we show that a single inoculation with a PGPR could affect the whole life cycle of a plant, accelerating its growth rate and shortening its vegetative period, both effects relevant for most crops. Thus, these findings provide novel and interesting aspects

  14. Screening of chlorpyrifos degrading bacteria CD7 and its combined application with PGPR JD37

    Directory of Open Access Journals (Sweden)

    Su Cuizhu

    2017-04-01

    Full Text Available We screened a chlorpyrifos degrading bacteria,Burkholderiasp. CD7.Joint with plant growth-promoting rhizobacteria(PGPR JD37 to produce a compositesoil amendment,which could restorethe pesticides polluted soil and promote plant growth.Results showed that CD7 and JD37 (at the volume ratio of 1:1 can promote the growth of plants,and within 25 days degrade about 66.43% chlorpyrifos in the soil.Further research found that under the same conditions of carrier dosage,vermicompost can adsorbed more bacteria than talcum powder;after a month preservation at room temperature,the number of living bacterium still maintained about 4.81×107 CFU/g.Carrier and soil,at the mass ratio of 1:1,could optimally promote plant growth,improve soil enzyme activities and increase the number of microorganisms in soil.

  15. Quantification of Azospirillum brasilense FP2 Bacteria in Wheat Roots by Strain-Specific Quantitative PCR.

    Science.gov (United States)

    Stets, Maria Isabel; Alqueres, Sylvia Maria Campbell; Souza, Emanuel Maltempi; Pedrosa, Fábio de Oliveira; Schmid, Michael; Hartmann, Anton; Cruz, Leonardo Magalhães

    2015-10-01

    Azospirillum is a rhizobacterial genus containing plant growth-promoting species associated with different crops worldwide. Azospirillum brasilense strains exhibit a growth-promoting effect by means of phytohormone production and possibly by N2 fixation. However, one of the most important factors for achieving an increase in crop yield by plant growth-promoting rhizobacteria is the survival of the inoculant in the rhizosphere, which is not always achieved. The objective of this study was to develop quantitative PCR protocols for the strain-specific quantification of A. brasilense FP2. A novel approach was applied to identify strain-specific DNA sequences based on a comparison of the genomic sequences within the same species. The draft genome sequences of A. brasilense FP2 and Sp245 were aligned, and FP2-specific regions were filtered and checked for other possible matches in public databases. Strain-specific regions were then selected to design and evaluate strain-specific primer pairs. The primer pairs AzoR2.1, AzoR2.2, AzoR5.1, AzoR5.2, and AzoR5.3 were specific for the A. brasilense FP2 strain. These primer pairs were used to monitor quantitatively the population of A. brasilense in wheat roots under sterile and nonsterile growth conditions. In addition, coinoculations with other plant growth-promoting bacteria in wheat were performed under nonsterile conditions. The results showed that A. brasilense FP2 inoculated into wheat roots is highly competitive and achieves high cell numbers (∼10(7) CFU/g [fresh weight] of root) in the rhizosphere even under nonsterile conditions and when coinoculated with other rhizobacteria, maintaining the population at rather stable levels for at least up to 13 days after inoculation. The strategy used here can be applied to other organisms whose genome sequences are available. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Studies of microbial development on mycorrhizosphere and ...

    African Journals Online (AJOL)

    Extracts from maize rhizosphere and mycorrhizosphere soil (both sterilized and unsterilized) were studied to assess the compatibility of the arbuscular mycorrhizae (AM) fungus (Glomus mosseae) with certain soil fungi, bacteria and rhizobacteria followed by assessment of the inhibitory effect of the identified rhizobacteria on ...

  17. Updated genome assembly and annotation of Paenibacillus larvae, the agent of American foulbrood disease of honey bees

    Directory of Open Access Journals (Sweden)

    de Graaf Dirk C

    2011-09-01

    Full Text Available Abstract Background As scientists continue to pursue various 'omics-based research, there is a need for high quality data for the most fundamental 'omics of all: genomics. The bacterium Paenibacillus larvae is the causative agent of the honey bee disease American foulbrood. If untreated, it can lead to the demise of an entire hive; the highly social nature of bees also leads to easy disease spread, between both individuals and colonies. Biologists have studied this organism since the early 1900s, and a century later, the molecular mechanism of infection remains elusive. Transcriptomics and proteomics, because of their ability to analyze multiple genes and proteins in a high-throughput manner, may be very helpful to its study. However, the power of these methodologies is severely limited without a complete genome; we undertake to address that deficiency here. Results We used the Illumina GAIIx platform and conventional Sanger sequencing to generate a 182-fold sequence coverage of the P. larvae genome, and assembled the data using ABySS into a total of 388 contigs spanning 4.5 Mbp. Comparative genomics analysis against fully-sequenced soil bacteria P. JDR2 and P. vortex showed that regions of poor conservation may contain putative virulence factors. We used GLIMMER to predict 3568 gene models, and named them based on homology revealed by BLAST searches; proteases, hemolytic factors, toxins, and antibiotic resistance enzymes were identified in this way. Finally, mass spectrometry was used to provide experimental evidence that at least 35% of the genes are expressed at the protein level. Conclusions This update on the genome of P. larvae and annotation represents an immense advancement from what we had previously known about this species. We provide here a reliable resource that can be used to elucidate the mechanism of infection, and by extension, more effective methods to control and cure this widespread honey bee disease.

  18. THE EFFECT OF SOME RHIZOBACTERIAN STRAINS ON SOLUBLE PROTEINS CONTENT IN SOYBEANS (GLYCINE MAX L. MERR.

    Directory of Open Access Journals (Sweden)

    Marius Stefan

    2007-08-01

    Full Text Available Now it is an accepted fact that plant growth-promoting rhizobacteria (PGPR can increase the productivity of several crops. The main objective of the present study was to find if there are any differences in protein content in the seeds of soybean (Glycine max L. MERR.. Using spectrophotometric methods for analyzing the protein contents and electrophoretic methods for qualitative analysis it was observed that no major modifications occur in protein spectrum. Looking at the quantitative side there was a small improvement in protein quantity.

  19. Bacteria from Wheat and Cucurbit Plant Roots Metabolize PAHs and Aromatic Root Exudates: Implications for Rhizodegradation

    DEFF Research Database (Denmark)

    Ely, Cairn S; Smets, Barth F.

    2017-01-01

    The chemical interaction between plants and bacteria in the root zone can lead to soil decontamination. Bacteria which degrade PAHs have been isolated from the rhizospheres of plant species with varied biological traits, however, it is not known what phytochemicals promote contaminant degradation....... One monocot and two dicotyledon plants were grown in PAH-contaminated soil from a manufactured gas plant (MGP) site. A phytotoxicity assay confirmed greater soil decontamination in rhizospheres when compared to bulk soil controls. Bacteria were isolated from plant roots (rhizobacteria) and selected...

  20. Molecular characterization of forest soil based Paenibacillus elgii and optimization of various culture conditions for its improved antimicrobial activity

    Directory of Open Access Journals (Sweden)

    S. N. Kumar

    2015-10-01

    Full Text Available Microorganisms have provided a bounty of bioactive secondary metabolites with very exciting biological activities such as antibacterial, antifungal antiviral, and anticancer, etc. The present study aims at the optimization of culture conditions for improved antimicrobial production of Paenibacillus elgii obtained from Wayanad forest of Western Ghats region of Kerala, India. A bacterial strain isolated from the Western Ghats forest soil of Wayanad, Kerala, India was identified as P. elgii by 16S rRNA gene sequencing. P. elgii recorded significant board spectrum activity against all human and plant pathogenic microorganism tested except Candida albicans. It has been well known that even minor variations in the fermentation medium may impact not only the quantity of desired bioactive metabolites but also the general metabolic profile of the producing microorganisms. Thus, further studies were carried out to assess the impact of medium components on the antimicrobial production of P. elgii and to optimize an ideal fermentation medium to maximize its antimicrobial production. Out of three media [nutrient broth (NA, Luria broth (LB and Trypticase soy broth (TSB] used for fermentation, TSB medium recorded significant activity. Glucose and meat peptone were identified as the best carbon and nitrogen sources, which significantly affected the antibiotic production when supplemented with TSB medium. Next the effect of various fermentation conditions such as temperature, pH, and incubation time on the production of antimicrobial compounds was studied on TSB + glucose + meat peptone and an initial pH of 7 and a temperature of 30°C for 3 days were found to be optimum for maximum antimicrobial production. The results indicate that medium composition in the fermentation media along with cultural parameters plays a vital role in the enhanced production of antimicrobial substances.

  1. Paenibacillus larvae chitin-degrading protein PlCBP49 is a key virulence factor in American Foulbrood of honey bees.

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    Eva Garcia-Gonzalez

    2014-07-01

    Full Text Available Paenibacillus larvae, the etiological agent of the globally occurring epizootic American Foulbrood (AFB of honey bees, causes intestinal infections in honey bee larvae which develop into systemic infections inevitably leading to larval death. Massive brood mortality might eventually lead to collapse of the entire colony. Molecular mechanisms of host-microbe interactions in this system and of differences in virulence between P. larvae genotypes are poorly understood. Recently, it was demonstrated that the degradation of the peritrophic matrix lining the midgut epithelium is a key step in pathogenesis of P. larvae infections. Here, we present the isolation and identification of PlCBP49, a modular, chitin-degrading protein of P. larvae and demonstrate that this enzyme is crucial for the degradation of the larval peritrophic matrix during infection. PlCBP49 contains a module belonging to the auxiliary activity 10 (AA10, formerly CBM33 family of lytic polysaccharide monooxygenases (LPMOs which are able to degrade recalcitrant polysaccharides. Using chitin-affinity purified PlCBP49, we provide evidence that PlCBP49 degrades chitin via a metal ion-dependent, oxidative mechanism, as already described for members of the AA10 family. Using P. larvae mutants lacking PlCBP49 expression, we analyzed in vivo biological functions of PlCBP49. In the absence of PlCBP49 expression, peritrophic matrix degradation was markedly reduced and P. larvae virulence was nearly abolished. This indicated that PlCBP49 is a key virulence factor for the species P. larvae. The identification of the functional role of PlCBP49 in AFB pathogenesis broadens our understanding of this important family of chitin-binding and -degrading proteins, especially in those bacteria that can also act as entomopathogens.

  2. Amino Groups of Chitosan Are Crucial for Binding to a Family 32 Carbohydrate Binding Module of a Chitosanase from Paenibacillus elgii*

    Science.gov (United States)

    Das, Subha Narayan; Wagenknecht, Martin; Nareddy, Pavan Kumar; Bhuvanachandra, Bhoopal; Niddana, Ramana; Balamurugan, Rengarajan; Swamy, Musti J.; Moerschbacher, Bruno M.; Podile, Appa Rao

    2016-01-01

    We report here the role and mechanism of specificity of a family 32 carbohydrate binding module (CBM32) of a glycoside hydrolase family 8 chitosanase from Paenibacillus elgii (PeCsn). Both the activity and mode of action of PeCsn toward soluble chitosan polymers were not different with/without the CBM32 domain of P. elgii (PeCBM32). The decreased activity of PeCsn without PeCBM32 on chitosan powder suggested that PeCBM32 increases the relative concentration of enzyme on the substrate and thereby enhanced enzymatic activity. PeCBM32 specifically bound to polymeric and oligomeric chitosan and showed very weak binding to chitin and cellulose. In isothermal titration calorimetry, the binding stoichiometry of 2 and 1 for glucosamine monosaccharide (GlcN) and disaccharide (GlcN)2, respectively, was indicative of two binding sites in PeCBM32. A three-dimensional model-guided site-directed mutagenesis and the use of defined disaccharides varying in the pattern of acetylation suggested that the amino groups of chitosan and the polar residues Glu-16 and Glu-38 of PeCBM32 play a crucial role for the observed binding. The specificity of CBM32 has been further elucidated by a generated fusion protein PeCBM32-eGFP that binds to the chitosan exposing endophytic infection structures of Puccinia graminis f. sp. tritici. Phylogenetic analysis showed that CBM32s appended to chitosanases are highly conserved across different chitosanase families suggesting their role in chitosan recognition and degradation. We have identified and characterized a chitosan-specific CBM32 useful for in situ staining of chitosans in the fungal cell wall during plant-fungus interaction. PMID:27405759

  3. Whole genome sequencing and analysis of plant growth promoting bacteria isolated from the rhizosphere of plantation crops coconut, cocoa and arecanut.

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    Alka Gupta

    Full Text Available Coconut, cocoa and arecanut are commercial plantation crops that play a vital role in the Indian economy while sustaining the livelihood of more than 10 million Indians. According to 2012 Food and Agricultural organization's report, India is the third largest producer of coconut and it dominates the production of arecanut worldwide. In this study, three Plant Growth Promoting Rhizobacteria (PGPR from coconut (CPCRI-1, cocoa (CPCRI-2 and arecanut (CPCRI-3 characterized for the PGP activities have been sequenced. The draft genome sizes were 4.7 Mb (56% GC, 5.9 Mb (63.6% GC and 5.1 Mb (54.8% GB for CPCRI-1, CPCRI-2, CPCRI-3, respectively. These genomes encoded 4056 (CPCRI-1, 4637 (CPCRI-2 and 4286 (CPCRI-3 protein-coding genes. Phylogenetic analysis revealed that both CPCRI-1 and CPCRI-3 belonged to Enterobacteriaceae family, while, CPCRI-2 was a Pseudomonadaceae family member. Functional annotation of the genes predicted that all three bacteria encoded genes needed for mineral phosphate solubilization, siderophores, acetoin, butanediol, 1-aminocyclopropane-1-carboxylate (ACC deaminase, chitinase, phenazine, 4-hydroxybenzoate, trehalose and quorum sensing molecules supportive of the plant growth promoting traits observed in the course of their isolation and characterization. Additionally, in all the three CPCRI PGPRs, we identified genes involved in synthesis of hydrogen sulfide (H2S, which recently has been proposed to aid plant growth. The PGPRs also carried genes for central carbohydrate metabolism indicating that the bacteria can efficiently utilize the root exudates and other organic materials as energy source. Genes for production of peroxidases, catalases and superoxide dismutases that confer resistance to oxidative stresses in plants were identified. Besides these, genes for heat shock tolerance, cold shock tolerance and glycine-betaine production that enable bacteria to survive abiotic stress were also identified.

  4. Optimal Concentration of Organic Solvents to be Used in the Broth Microdilution Method to Determine the Antimicrobial Activity of Natural Products Against Paenibacillus Larvae

    Directory of Open Access Journals (Sweden)

    Cugnata Noelia Melina

    2017-06-01

    Full Text Available American Foulbrood (AFB is a bacterial disease, caused by Paenibacillus larvae, that affects honeybees (Apis mellifera. Alternative strategies to control AFB are based on the treatment of the beehives with antimicrobial natural substances such as extracts, essential oils and/or pure compounds from plants, honey by-products, bacteria and moulds. The broth microdilution method is currently one of the most widely used methods to determine the minimum inhibitory concentration (MIC of a substance. In this regard, the fact that most natural products, due to their lipophilic nature, must be dissolved in organic solvents or their aqueous mixtures is an issue of major concern because the organic solvent becomes part of the dilution in the incubation medium, and therefore, can interfere with bacterial viability depending on its nature and concentration. A systematic study was carried out to determine by the broth microdilution method the MIC and the maximum non inhibitory concentration (MNIC against P. larvae of the most common organic solvents used to extract or dissolve natural products, i.e. ethanol, methanol, acetonitrile, n-butanol, dimethylsulfoxide, and acidified hydromethanolic solutions. From the MIC and MNIC for each organic solvent, recommended maximum concentrations in contact with P. larvae were established: DMSO 5% (v/v, acetonitrile 7.5% (v/v, ethanol 7.5% (v/v, methanol 12% (v/v, n-butanol 1% (v/v, and methanol-water-acetic acid (1.25:98.71:0.04, v/v/v.

  5. Induction of Systemic Resistance against Insect Herbivores in Plants by Beneficial Soil Microbes

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    Md. Harun-Or Rashid

    2017-10-01

    Full Text Available Soil microorganisms with growth-promoting activities in plants, including rhizobacteria and rhizofungi, can improve plant health in a variety of different ways. These beneficial microbes may confer broad-spectrum resistance to insect herbivores. Here, we provide evidence that beneficial microbes modulate plant defenses against insect herbivores. Beneficial soil microorganisms can regulate hormone signaling including the jasmonic acid, ethylene and salicylic acid pathways, thereby leading to gene expression, biosynthesis of secondary metabolites, plant defensive proteins and different enzymes and volatile compounds, that may induce defenses against leaf-chewing as well as phloem-feeding insects. In this review, we discuss how beneficial microbes trigger induced systemic resistance against insects by promoting plant growth and highlight changes in plant molecular mechanisms and biochemical profiles.

  6. Paenibacillus larvae 16S-23S rDNA intergenic transcribed spacer (ITS) regions: DNA fingerprinting and characterization.

    Science.gov (United States)

    Dingman, Douglas W

    2012-07-01

    Paenibacillus larvae is the causative agent of American foulbrood in honey bee (Apis mellifera) larvae. PCR amplification of the 16S-23S ribosomal DNA (rDNA) intergenic transcribed spacer (ITS) regions, and agarose gel electrophoresis of the amplified DNA, was performed using genomic DNA collected from 134 P. larvae strains isolated in Connecticut, six Northern Regional Research Laboratory stock strains, four strains isolated in Argentina, and one strain isolated in Chile. Following electrophoresis of amplified DNA, all isolates exhibited a common migratory profile (i.e., ITS-PCR fingerprint pattern) of six DNA bands. This profile represented a unique ITS-PCR DNA fingerprint that was useful as a fast, simple, and accurate procedure for identification of P. larvae. Digestion of ITS-PCR amplified DNA, using mung bean nuclease prior to electrophoresis, characterized only three of the six electrophoresis bands as homoduplex DNA and indicating three true ITS regions. These three ITS regions, DNA migratory band sizes of 915, 1010, and 1474 bp, signify a minimum of three types of rrn operons within P. larvae. DNA sequence analysis of ITS region DNA, using P. larvae NRRL B-3553, identified the 3' terminal nucleotides of the 16S rRNA gene, 5' terminal nucleotides of the 23S rRNA gene, and the complete DNA sequences of the 5S rRNA, tRNA(ala), and tRNA(ile) genes. Gene organization within the three rrn operon types was 16S-23S, 16S-tRNA(ala)-23S, and l6S-5S-tRNA(ile)-tRNA(ala)-23S and these operons were named rrnA, rrnF, and rrnG, respectively. The 23S rRNA gene was shown by I-CeuI digestion and pulsed-field gel electrophoresis of genomic DNA to be present as seven copies. This was suggestive of seven rrn operon copies within the P. larvae genome. Investigation of the 16S-23S rDNA regions of this bacterium has aided the development of a diagnostic procedure and has helped genomic mapping investigations via characterization of the ITS regions. Copyright © 2012 Elsevier Inc

  7. Biocontrol and Plant Growth Promotion Characterization of Bacillus Species Isolated from Calendula officinalis Rhizosphere.

    Science.gov (United States)

    Ait Kaki, Asma; Kacem Chaouche, Noreddine; Dehimat, Laid; Milet, Asma; Youcef-Ali, Mounia; Ongena, Marc; Thonart, Philippe

    2013-12-01

    The phenotypic and genotypic diversity of the plant growth promoting Bacillus genus have been widely investigated in the rhizosphere of various agricultural crops. However, to our knowledge this is the first report on the Bacillus species isolated from the rhizosphere of Calendula officinalis. 15 % of the isolated bacteria were screened for their important antifungal activity against Fusarium oxysporum, Botrytis cinerea, Aspergillus niger, Cladosporium cucumerinium and Alternaria alternata. The bacteria identification based on 16S r-RNA and gyrase-A genes analysis, revealed strains closely related to Bacillus amyloliquefaciens, B. velezensis, B. subtilis sub sp spizezenii and Paenibacillus polymyxa species. The electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC MS) analysis showed that most of the Bacillus isolates produced the three lipopeptides families. However, the P. polymyxa (18SRTS) didn't produce any type of lipopeptides. All the tested Bacillus isolates produced cellulase but the protease activity was observed only in the B. amyloliquefaciens species (9SRTS). The Salkowsky colorimetric test showed that the screened bacteria synthesized 6-52 μg/ml of indole 3 acetic acid. These bacteria produced siderophores with more than 10 mm wide orange zones on chromazurol S. The greenhouse experiment using a naturally infested soil with Sclerotonia sclerotiorum showed that the B. amyloliquefaciens (9SRTS) had no significant (P > 0.05) effect on the pre-germination of the chickpea seeds. However, it increased the size of the chickpea plants and reduced the stem rot disease (P Bacillus strains isolated in this work may be further used as bioinoculants to improve the production of C. officinalis and other crop systems.

  8. Arsenic-tolerant plant-growth-promoting bacteria isolated from arsenic-polluted soils in South Korea.

    Science.gov (United States)

    Shagol, Charlotte C; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sundaram, Subbiah; Sa, Tongmin

    2014-01-01

    The Janghang smelter in Chungnam, South Korea started in 1936 was subsequently shutdown in 1989 due to heavy metal (loid) pollution concerns in the vicinity. Thus, there is a need for the soil in the area to be remediated to make it usable again especially for agricultural purposes. The present study was conducted to exploit the potential of arsenic (As)-tolerant bacteria thriving in the vicinity of the smelter-polluted soils to enhance phytoremediation of hazardous As. We studied the genetic and taxonomic diversity of 21 As-tolerant bacteria isolated from soils nearer to and away from the smelter. These isolates belonging to the genera Brevibacterium, Pseudomonas, Microbacterium, Rhodococcus, Rahnella, and Paenibacillus, could tolerate high concentrations of arsenite (As(III)) and arsenate (As(V)) with the minimum inhibitory concentration ranging from 3 to >20 mM for NaAsO2 and 140 to 310 mM NaH2AsO4 · 7H2O, respectively. All isolates exhibited As(V) reduction except Pseudomonas koreensis JS123, which exhibited both oxidation and reduction of As. Moreover, all the 21 isolates produced indole acetic acid (IAA), 13 isolates exhibited 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 12 produced siderophore, 17 solubilized phosphate, and 13 were putative nitrogen fixers under in vitro conditions. Particularly, Rhodococcus aetherivorans JS2210, P. koreensis JS2214, and Pseudomonas sp. JS238 consistently increased root length of maize in the presence of 100 and 200 μM As(V). Possible utilization of these As-tolerant plant-growth-promoting bacteria can be a potential strategy in increasing the efficiency of phytoremediation in As-polluted soils.

  9. Pemberian Macam Konsorsium Bakteri Hasil Isolasi Tumbuhan Pantai pada Kangkung (Ipomoea reptans Poirs.

    Directory of Open Access Journals (Sweden)

    Umul Aiman

    2017-06-01

    Full Text Available Bacteria consortium isolated from coastal plant was used as Plant Growth Promoting Rhizobacteria (PGPR which can improve the growth and yield of plant. The purpose of this research was to understand the effects of various bacteria consortium application on the growth and yield of water spinach. The research was conducted on June-September 2016 in Microbiology Laboratory, Agroindustry Laboratory and Agriculture Land, University of Mercu Buana Yogyakarta. The study used a single factor experiment with 16 treatments and 3 blocks which arranged using completely randomized design (CRD. The treatment was desinged by soaking the water spinach seed on the various PGPR consorcium. All treatments were control (seed soaking on the water or without PGPR, the seed soaking on the various PGPR consorsium including K2, K9, K15, C7, K2K9, K2K15, K2C7, K9K15, K9C7, K15C7, K2K9K15, K2K9C7, K9K15C7, K2K15C7, and K2K9K15C7. The economic weight of water spinach which soaking on K2K9K15C7 consorcium was the best treatments compare to other treatments. Application of single isolate including K2, K9, K15, C7 and rhizobacteria consortium including K2K9, K2K15, K2C7, K9K15, K9C7, K15C7, K2K9K15, K2K9C7, K9K15C7, K2K15C7 can improved the yield of water spinach compare to the treatment without application of rhizobacteria.

  10. Successful field tests of a multi-process phytoremediation system for decontamination of persistent petroleum and organic contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, B.M.; Huang, X.D.; Gurska, Y.; Gerhardt, K.E.; Wang, W.; Lampi, M.A.; Zhang, C.; Khalid, A.; Isherwood, D.; Chang, P.; Wang, H.; Dixon, D.G.; Glick, B.R. [Waterloo Univ., ON (Canada)

    2006-07-01

    A large number of aquatic and terrestrial environments are polluted with various levels of toxicants. Metals, organics and total petroleum hydrocarbons from anthropogenic sources pose a risk to both human health and the health of ecosystems. Although these persistent contaminants are difficult to remediate, several industrial sites throughout North America are being remediated as part of land reclamation and restoration programs. This paper addressed the issue of phytoremediation for removing contaminants from soils. Phytoremediation is considered to be a viable remediation strategy because the increased biomass of plants, relative to the biomass of soil microbes in the absence of plants, allows for higher throughput. Extensive root systems can infiltrate large volumes of soil, thus promoting degradation of contaminants over a wide area. This paper described a newly developed multi-process phytoremediation system with accelerated remediation kinetics to effectively remove polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH) and chlorinated hydrocarbons (CHC) from soils. The system combines land farming/sunlight exposure; inoculation of contaminant degrading bacteria; and, plant growth with plant growth promoting rhizobacteria which mitigates the effects of stress ethylene in plants. The primary factor for success was the interaction between the plant and the plant growth promoting rhizobacteria. Several field tests were conducted following successful greenhouse tests. Results at a TPH contaminated site in Sarnia, Ontario showed that over a 2 year period, 60 to 70 per cent remediation of 15 per cent TPH was achieved. At a site in Turner Valley, Alberta, 35 per cent remediation of 1 per cent recalcitrant TPH was achieved, while a DDT contaminated site near Simcoe, Ontario had nearly 30 per cent of CHC removed in a 3 month period. 34 refs., 2 tabs., 2 figs.

  11. Successful field tests of a multi-process phytoremediation system for decontamination of persistent petroleum and organic contaminants

    International Nuclear Information System (INIS)

    Greenberg, B.M.; Huang, X.D.; Gurska, Y.; Gerhardt, K.E.; Wang, W.; Lampi, M.A.; Zhang, C.; Khalid, A.; Isherwood, D.; Chang, P.; Wang, H.; Dixon, D.G.; Glick, B.R.

    2006-01-01

    A large number of aquatic and terrestrial environments are polluted with various levels of toxicants. Metals, organics and total petroleum hydrocarbons from anthropogenic sources pose a risk to both human health and the health of ecosystems. Although these persistent contaminants are difficult to remediate, several industrial sites throughout North America are being remediated as part of land reclamation and restoration programs. This paper addressed the issue of phytoremediation for removing contaminants from soils. Phytoremediation is considered to be a viable remediation strategy because the increased biomass of plants, relative to the biomass of soil microbes in the absence of plants, allows for higher throughput. Extensive root systems can infiltrate large volumes of soil, thus promoting degradation of contaminants over a wide area. This paper described a newly developed multi-process phytoremediation system with accelerated remediation kinetics to effectively remove polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH) and chlorinated hydrocarbons (CHC) from soils. The system combines land farming/sunlight exposure; inoculation of contaminant degrading bacteria; and, plant growth with plant growth promoting rhizobacteria which mitigates the effects of stress ethylene in plants. The primary factor for success was the interaction between the plant and the plant growth promoting rhizobacteria. Several field tests were conducted following successful greenhouse tests. Results at a TPH contaminated site in Sarnia, Ontario showed that over a 2 year period, 60 to 70 per cent remediation of 15 per cent TPH was achieved. At a site in Turner Valley, Alberta, 35 per cent remediation of 1 per cent recalcitrant TPH was achieved, while a DDT contaminated site near Simcoe, Ontario had nearly 30 per cent of CHC removed in a 3 month period. 34 refs., 2 tabs., 2 figs

  12. Endophytic Bacterium Pseudomonas fluorescens RG11 May Transform Tryptophan to Melatonin and Promote Endogenous Melatonin Levels in the Roots of Four Grape Cultivars.

    Science.gov (United States)

    Ma, Yaner; Jiao, Jian; Fan, Xiucai; Sun, Haisheng; Zhang, Ying; Jiang, Jianfu; Liu, Chonghuai

    2016-01-01

    Endophytes have been verified to synthesize melatonin in vitro and promote abiotic stress-induced production of endogenous melatonin in grape ( Vitis vinifera L.) roots. This study aimed to further characterize the biotransformation of tryptophan to melatonin in the endophytic bacterium Pseudomonas fluorescens RG11 and to investigate its capacity for enhancing endogenous melatonin levels in the roots of different grape cultivars. Using ultra performance liquid chromatography-tandem mass spectrometry combined with 15N double-labeled L -tryptophan as the precursor for melatonin, we detected isotope-labeled 5-hydroxytryptophan, serotonin, N -acetylserotonin, and melatonin, but tryptamine was not detected during the in vitro incubation of P. fluorescens RG11. Furthermore, the production capacity of these four compounds peaked during the exponential growth phase. RG11 colonization increased the endogenous levels of 5-hydroxytryptophan, N -acetylserotonin, and melatonin, but reduced those of tryptamine and serotonin, in the roots of the Red Globe grape cultivar under salt stress conditions. Quantitative real-time PCR revealed that RG11 reduced the transcription of grapevine tryptophan decarboxylase and serotonin N -acetyltransferase genes when compared to the un-inoculated control. These results correlated with decreased reactive oxygen species bursts and cell damage, which were alleviated by RG11 colonization under salt stress conditions. Additionally, RG11 promoted plant growth and enhanced the levels of endogenous melatonin in different grape cultivars. Intraspecific variation in the levels of melatonin precursors was found among four grape cultivars, and the associated root crude extracts appeared to significantly induce RG11 melatonin biosynthesis in vitro . Overall, this study provides useful information that enhances the existing knowledge of a potential melatonin synthesis pathway in rhizobacteria, and it reveals plant-rhizobacterium interactions that affect

  13. A drought resistance-promoting microbiome is selected by root system under desert farming.

    Directory of Open Access Journals (Sweden)

    Ramona Marasco

    Full Text Available BACKGROUND: Traditional agro-systems in arid areas are a bulwark for preserving soil stability and fertility, in the sight of "reverse desertification". Nevertheless, the impact of desert farming practices on the diversity and abundance of the plant associated microbiome is poorly characterized, including its functional role in supporting plant development under drought stress. METHODOLOGY/PRINCIPAL FINDINGS: We assessed the structure of the microbiome associated to the drought-sensitive pepper plant (Capsicum annuum L. cultivated in a traditional Egyptian farm, focusing on microbe contribution to a crucial ecosystem service, i.e. plant growth under water deficit. The root system was dissected by sampling root/soil with a different degree of association to the plant: the endosphere, the rhizosphere and the root surrounding soil that were compared to the uncultivated soil. Bacterial community structure and diversity, determined by using Denaturing Gradient Gel Electrophoresis, differed according to the microhabitat, indicating a selective pressure determined by the plant activity. Similarly, culturable bacteria genera showed different distribution in the three root system fractions. Bacillus spp. (68% of the isolates were mainly recovered from the endosphere, while rhizosphere and the root surrounding soil fractions were dominated by Klebsiella spp. (61% and 44% respectively. Most of the isolates (95% presented in vitro multiple plant growth promoting (PGP activities and stress resistance capabilities, but their distribution was different among the root system fractions analyzed, with enhanced abilities for Bacillus and the rhizobacteria strains. We show that the C. annuum rhizosphere under desert farming enriched populations of PGP bacteria capable of enhancing plant photosynthetic activity and biomass synthesis (up to 40% under drought stress. CONCLUSIONS/SIGNIFICANCE: Crop cultivation provides critical ecosystem services in arid lands with the

  14. Beneficial rhizobacteria

    DEFF Research Database (Denmark)

    Michelsen, Charlotte Frydenlund

    Potatoes are cultivated in Southwest Greenland without the use of pesticides and with limited crop rotation. However, despite the fact that plant-pathogenic fungi are present in the Greenlandic potato soils, no severe disease outbreaks, such as late blight, have been observed. In this PhD project...

  15. Study of qualitative and quantitative yield and some agronomic characteristics of sunflower (Helianthus annus L. in response of seed inoculation with PGPR in various levels of nitrogen fertilizer

    Directory of Open Access Journals (Sweden)

    H. Nazarly

    2016-05-01

    Full Text Available In order to study the qualitative and quantitative yield and some agronomic characteristics of sunflower (Helianthus annus L. in response to seed inoculation with PGPR under various levels of nitrogen fertilizer, a factorial experiment was conducted based on a randomized complete block design with three replications in field experimental University of Mohaghegh Ardabili during growing season of 2009-2010. Factors were nitrogen fertilizer in three levels (0, 80 and 160 kg N ha-1 as urea and seed inoculation with plant growth promoting rhizobacteria in four levels containing, without inoculation (as control, seed inoculation with Azotobacter chroococcum strain 5, Azospirillum lipoferum strain OF, Psedomunas strain 186. Results indicated that nitrogen levels and seed inoculation with Plant Growth Promoting Rhizobacteria (PGPR had significant effects on all of characteristics studied (except grain 1000 weight and stem diameter. Grain yield, plant height, head diameter, seed number per head, , yield and oil percentage, yield and protein percentage increased with increasing of nitrogen fertilizer and application of seed inoculation with PGPR. Response of grain yield wasn't the same for various levels of nitrogen fertilizer and seed inoculation with PGPR. The highest grain yield belonged to application of 160 kg N ha-1 and seed inoculation with Azotobacter. Means comparison showed that treatment compounds N160 × without inoculation with PGPR and N80 × seed inoculation with PGPR Azotobacter had similar grain yields. Thus, it can be suggested that in order to increasing of grain yield seed should be inoculated with Azotobacter bacteria × 80 kg N/ha in conditions of Ardabil region.

  16. Effect of Pseudomonas putida on Growth and Anthocyanin Pigment in Two Poinsettia (Euphorbia pulcherrima Cultivars

    Directory of Open Access Journals (Sweden)

    Ramon Zulueta-Rodriguez

    2014-01-01

    Full Text Available Pseudomonas putida is plant growth promoting rhizobacteria (PGPR that have the capacity to improve growth in plants. The purpose of this study was to determine growth and anthocyanin pigmentation of the bracts in two poinsettia Euphorbia pulcherrima cultivars (Prestige and Sonora Marble using three strains of P. putida, as well as a mixture of the three (MIX. Comparison with the control group indicated for the most part that Prestige grew better than the Sonora Marble cultivars with the PGPR strains. Prestige with the MIX strain grew better compared to control for the number of cyathia (83 versus 70.4, volume of roots (45 versus 35 cm3, number of leaves (78 versus 58, and area of leaf (1,788 versus 1,331 cm2, except for the number of flowers (8.8 versus 11.6. To the naked eye, coloration of plants appeared identical in color compared to the control group. For all plants with P. putida strains, there was less anthocyanin pigment, but biomass was always greater with PGPR strains. Nevertheless, to the naked eye, the coloration of the plants appeared identical in color compared to the control group. This is the first study reporting the positive effects of P. putida rhizobacteria treatments on growth of poinsettia cultivars.

  17. Oxidative and antioxidative responses in the wheat-Azospirillum brasilense interaction.

    Science.gov (United States)

    Méndez-Gómez, Manuel; Castro-Mercado, Elda; Alexandre, Gladys; García-Pineda, Ernesto

    2016-03-01

    Azospirillum is a plant growth-promoting rhizobacteria (PGPR) able to enhance the growth of wheat. The aim of this study was to test the effect of Azospirillum brasilense cell wall components on superoxide (O2·(-)) production in wheat roots and the effect of oxidative stress on A. brasilense viability. We found that inoculation with A. brasilense reduced O2·(-) levels by approx. 30 % in wheat roots. Inoculation of wheat with papain-treated A. brasilense, a Cys protease, notably increased O2·(-) production in all root tissues, as was observed by the nitro blue tetrazolium (NBT) reduction. However, a 24-h treatment with rhizobacteria lipopolysaccharides (50 and 100 μg/mL) alone did not affect the pattern of O2·(-) production. Analysis of the effect of plant cell wall components on A. brasilense oxidative enzyme activity showed no changes in catalase activity but a decrease in superoxide dismutase activity in response to polygalacturonic acid treatment. Furthermore, A. brasilense growth was only affected by high concentrations of H2O2 or paraquat, but not by sodium nitroprusside. Our results suggest that rhizobacterial cell wall components play an important role in controlling plant cell responses and developing tolerance of A. brasilense to oxidative stress produced by the plant.

  18. Diversity of endophytic fungal and bacterial communities in Ilex paraguariensis grown under field conditions.

    Science.gov (United States)

    Pérez, María Laura; Collavino, Mónica Mariana; Sansberro, Pedro Alfonso; Mroginski, Luis Amado; Galdeano, Ernestina

    2016-04-01

    The composition and diversity of the endophytic community associated with yerba mate (Ilex paraguariensis) was investigated using culture-depending methods. Fungi were identified based on their micromorphological characteristics and internal transcribed spacer rDNA sequence analysis; for bacteria 16S rDNA sequence analysis was used. Fungal and bacterial diversity did not show significant differences between organ age. The highest fungal diversity was registered during fall season and the lowest in winter. Bacterial diversity was higher in stems and increased from summer to winter, in contrast with leaves, which decreased. The most frequently isolated fungus was Fusarium, followed by Colletotrichum; they were both present in all the sampling seasons and organ types assayed. Actinobacteria represented 57.5 % of all bacterial isolates. The most dominant bacterial taxa were Curtobacterium and Microbacterium. Other bacteria frequently found were Methylobacterium, Sphingomonas, Herbiconiux and Bacillus. Nitrogen fixation and phosphate solubilization activity, ACC deaminase production and antagonism against plant fungal pathogens were assayed in endophytic bacterial strains. In the case of fungi, strains of Trichoderma, Penicillium and Aspergillus were assayed for antagonism against pathogenic Fusarium sp. All microbial isolates assayed showed at least one growth promoting activity. Strains of Bacillus, Pantoea, Curtobacterium, Methylobacterium, Brevundimonas and Paenibacillus had at least two growth-promoting activities, and Bacillus, Paenibacillus and the three endophytic fungi showed high antagonistic activity against Fusarium sp. In this work we have made a wide study of the culturable endophytic community within yerba mate plants and found that several microbial isolates could be considered as potential inoculants useful for improving yerba mate production.

  19. Isolation, Screening, and Identification of Cellulolytic Bacteria from Natural Reserves in the Subtropical Region of China and Optimization of Cellulase Production by Paenibacillus terrae ME27-1

    Directory of Open Access Journals (Sweden)

    Yan-Ling Liang

    2014-01-01

    Full Text Available From different natural reserves in the subtropical region of China, a total of 245 aerobic bacterial strains were isolated on agar plates containing sugarcane bagasse pulp as the sole carbon source. Of the 245 strains, 22 showed hydrolyzing zones on agar plates containing carboxymethyl cellulose after Congo-red staining. Molecular identification showed that the 22 strains belonged to 10 different genera, with the Burkholderia genus exhibiting the highest strain diversity and accounting for 36.36% of all the 22 strains. Three isolates among the 22 strains showed higher carboxymethyl cellulase (CMCase activity, and isolate ME27-1 exhibited the highest CMCase activity in liquid culture. The strain ME27-1 was identified as Paenibacillus terrae on the basis of 16S rRNA gene sequence analysis as well as physiological and biochemical properties. The optimum pH and temperature for CMCase activity produced by the strain ME27-1 were 5.5 and 50°C, respectively, and the enzyme was stable at a wide pH range of 5.0–9.5. A 12-fold improvement in the CMCase activity (2.08 U/mL of ME27-1 was obtained under optimal conditions for CMCase production. Thus, this study provided further information about the diversity of cellulose-degrading bacteria in the subtropical region of China and found P. terrae ME27-1 to be highly cellulolytic.

  20. Characterization of Pseudomonas chlororaphis from Theobroma cacao L. rhizosphere with antagonistic activity against Phytophthora palmivora (Butler).

    Science.gov (United States)

    Acebo-Guerrero, Y; Hernández-Rodríguez, A; Vandeputte, O; Miguélez-Sierra, Y; Heydrich-Pérez, M; Ye, L; Cornelis, P; Bertin, P; El Jaziri, M

    2015-10-01

    To isolate and characterize rhizobacteria from Theobroma cacao with antagonistic activity against Phytophthora palmivora, the causal agent of the black pod rot, which is one of the most important diseases of T. cacao. Among 127 rhizobacteria isolated from cacao rhizosphere, three isolates (CP07, CP24 and CP30) identified as Pseudomonas chlororaphis, showed in vitro antagonistic activity against P. palmivora. Direct antagonism tested in cacao detached leaves revealed that the isolated rhizobacteria were able to reduce symptom severity upon infection with P. palmivora Mab1, with Ps. chlororaphis CP07 standing out as a potential biocontrol agent. Besides, reduced symptom severity on leaves was also observed in planta where cacao root system was pretreated with the isolated rhizobacteria followed by leaf infection with P. palmivora Mab1. The production of lytic enzymes, siderophores, biosurfactants and HCN, as well as the detection of genes encoding antibiotics, the formation of biofilm, and bacterial motility were also assessed for all three rhizobacterial strains. By using a mutant impaired in viscosin production, derived from CP07, it was found that this particular biosurfactant turned out to be crucial for both motility and biofilm formation, but not for the in vitro antagonism against Phytophthora, although it may contribute to the bioprotection of T. cacao. In the rhizosphere of T. cacao, there are rhizobacteria, such as Ps. chlororaphis, able to protect plants against P. palmivora. This study provides a theoretical basis for the potential use of Ps. chlororaphis CP07 as a biocontrol agent for the protection of cacao plants from P. palmivora infection. © 2015 The Society for Applied Microbiology.

  1. Robust biological nitrogen fixation in a model grass-bacterial association.

    Science.gov (United States)

    Pankievicz, Vânia C S; do Amaral, Fernanda P; Santos, Karina F D N; Agtuca, Beverly; Xu, Youwen; Schueller, Michael J; Arisi, Ana Carolina M; Steffens, Maria B R; de Souza, Emanuel M; Pedrosa, Fábio O; Stacey, Gary; Ferrieri, Richard A

    2015-03-01

    Nitrogen-fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen-13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen-limiting conditions when inoculated with an ammonium-excreting strain of Azospirillum brasilense. (11)C-labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen-starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen-sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  2. Isolation, identification of antagonistic rhizobacterial strains obtained from chickpea (cicer arietinum l.) field and their in-vitro evaluation against fungal root pathogens

    International Nuclear Information System (INIS)

    Shahzaman, S.; Haq, I.U.; Mukhtar, T.; Naeem, M.

    2015-01-01

    Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen. (author)

  3. Population Growth Parameters of Tuta absoluta (Lepidoptera: Gelechiidae) on Tomato Plant Using Organic Substrate and Biofertilizers.

    Science.gov (United States)

    Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M

    2017-01-01

    The tomato leafminer, Tuta absoluta (Meyrick) is a devastating pest associated with tomato. In this study, effects of tomato plants treated with vermicompost (20, 40, and 60%), humic fertilizer (2, 4 and 6 g/kg soil) and plant growth promoting rhizobacteria (Pseudomonas fluorescens and Bacillus subtilis) were investigated on the life table parameters of T. absoluta in a growth chamber at 25 ± 2 °C, 65 ± 5% RH, and 16:8 (L:D) h. Significant differences were found for the total developmental time, fecundity, and oviposition period of T. absoluta on the treatments tested. The net reproductive rate (R0), intrinsic rate of natural increase (rm), finite rate of increase (λ), mean generation time (T), and doubling time (DT) of T. absoluta were significantly different among treatments tested. We found that in all vermicompost, humic fertilizer and plant growth promoting rhizobacteria treatments, values of R0, rm, and λ were lower than control treatment. However, the lowest values of these parameters were obtained on 2 g/kg humic fertilizer and 40% vermicompost. Furthermore, T. absoluta had longest T and DT values on 2 g/kg humic fertilizer treatment. Data obtained showed that the addition of 2 g/kg humic fertilizer and 40% vermicompost to the growing soil reduced T. absoluta populations in tomato cultures. In addition, these levels of fertilizers improved growth parameters of tomato seedlings (plant height, wet weight, and dry weight) compared with other treatments. These results could be useful in improving the sustainable management of the moth. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

  4. Molecular Characterization of the Plant Growth Promoting Bacterium Enterobacter sp. SA187 upon Contact with Arabidopsis thaliana

    KAUST Repository

    Alsharif, Wiam

    2018-05-01

    Salt stress is a severe environmental challenge in agriculture, limiting the quality and productivity of the crops around the globe. Plant growth promoting rhizobacteria (PGPR) is proposed as a friendly solution to overcome those challenges. The desert plant endophytic bacterium, Enterobacter sp. SA187 has shown plant growth promotion and salt stress tolerance beneficial effect on the model plant Arabidopsis thaliana in vitro as well as under the field conditions on different crops. SA187 has a distinguished morphology of yellow colonies (SA187Y) that could be due to carotenoid biosynthesis. However, the bacteria tend to lose the yellow color upon incubation with the plants and the colonies turn to white (SA187W). In comparison to SA187Y, SA187W shows 50% reduction on the beneficial impact on A. thaliana fresh and dry weight of root and shoot system. By counting the CFU/plant, we showed that SA187Y and SA187W both have similar colonization rate in both shoots and roots. Under non-salt conditions, optimal bacterial colonization was observed on day 8 after inocubation, however, under the salt stress condition, the optimal colonization was observed at day 4. Moreover, during the time period of the incubation of the SA187Y with the plants, there was a consistent noticeable loss of the yellow color of the colonies. This change in color is only observed eight days after transfer and the number of white colonies increases with the increase of the incubation time. In addition, SA187W was GFP-tagged by Tn7 transposon system and visualized by confocal laser scanning microscopy. The SA187W-GFP colonies have shown a similar colonization pattern as SA187Y-GFP, bacteria were colonizing the differentiation zone and cell elongation zone in the roots. Finally, the gene expression of the carotenoid biosynthesis pathways genes in SA187Y showed an overall higher gene expression compared to SA187W. In conclusion, the color loss seems to affect the beneficial impact of the bacteria on

  5. Aggregation of the rhizospheric bacterium Azospirillum brasilense in response to oxygen

    Science.gov (United States)

    Abdoun, Hamid; McMillan, Mary; Pereg, Lily

    2016-04-01

    Azospirillum brasilense spp. have ecological, scientific and agricultural importance. As model plant growth promoting rhizobacteria they interact with a large variety of plants, including important food and cash crops. Azospirillum strains are known for their production of plant growth hormones that enhance root systems and for their ability to fix nitrogen. Azospirillum cells transform in response to environmental cues. The production of exopolysaccharides and cell aggregation during cellular transformation are important steps in the attachment of Azospirillum to roots. We investigate signals that induce cellular transformation and aggregation in the Azospirillum and report on the importance of oxygen to the process of aggregation in this rhizospheric bacterium.

  6. Effect of Arthrobacter agilis UMCV2 on germination and growth of Pinus devoniana Lindley

    Directory of Open Access Journals (Sweden)

    Wilber Montejo-Mayo

    2016-03-01

    Full Text Available Soil microorganisms are essential for growth, emergence and development in all plants. In our study we decided to evaluate the effect that A. agilis UMCV2 rhizobacteria had on germination and growth of plants of economic-forest interest as P. devoniana to an age of 65 days. Our results show that the UMCV2 bacteria promoted growth of P. devoniana at this early stage of development, further highlighting that despite the short time of interaction between these two, the bacterium was able to increase the rate of germination, increase the size of shoot and generate a proliferation of lateral roots. The data shows a huge potential for using inoculum both in the greenhouse and in open ground and generate a growth promoting species of interest in both agricultural and forest, thereby reducing production periods depending on the crop.

  7. Comparison of plant growth-promotion with Pseudomonas aeruginosa and Bacillus subtilis in three vegetables Comparação da promoção de crescimento de plantas por Pseudomonas aeruginosa e Bacillus subtilis em três vegetais

    Directory of Open Access Journals (Sweden)

    A.O. Adesemoye

    2008-09-01

    Full Text Available Our objective was to compare some plant growth promoting rhizobacteria (PGPR properties of Bacillus subtilis and Pseudomonas aeruginosa as representatives of their two genera. Solanum lycopersicum L. (tomato, Abelmoschus esculentus (okra, and Amaranthus sp. (African spinach were inoculated with the bacterial cultures. At 60 days after planting, dry biomass for plants treated with B. subtilis and P. aeruginosa increased 31% for tomato, 36% and 29% for okra, and 83% and 40% for African spinach respectively over the non-bacterized control. Considering all the parameters tested, there were similarities but no significant difference at P Nosso objetivo foi comparar as propriedades PGPR (rizobactérias promotoras de crescimento de plantas de Bacillus subtilis e Pseudomonas aeruginosa. Solanum licopersicum (tomate, Asbelmoschus esculentus (ocra e Amaranthus sp (espinafre africano foram inoculados com as culturas bacterianas. Após 60 dias de plantio, a biomassa seca das plantas tratadas com B.subtilis e P. aeruginosa aumentou 31% para o tomate, 36% e 29% para ocra, e 83% e 40% para espinafre africano, respectivamente, em comparação com o controle não inoculado. Considerando os parâmetros testados, o desempenho dos dois microrganismos foi similar, sem diferença estatisticamente significativa (p< 0,05.

  8. Physiological and proteomic analysis of plant growth enhancement by the rhizobacteria Bacillus sp. JS.

    Science.gov (United States)

    Kim, Ji Seong; Lee, Jeong Eun; Nie, Hualin; Lee, Yong Jae; Kim, Sun Tae; Kim, Sun-Hyung

    2018-02-01

    In this study, the effects of the plant growth-promoting rhizobacterium (PGPR), Bacillus sp. JS on the growth of tobacco (Nicotiana tabacum 'Xanthi') and lettuce (Lactuca sativa 'Crispa'), were evaluated by comparing various growth parameters between plants treated with the bacterium and those exposed to water or nutrient broth as control. In both tobacco and lettuce, fresh weight and length of shoots were increased upon exposure to Bacillus sp. JS. To explain the overall de novo expression of plant proteins by bacterial volatiles, two-dimensional gel electrophoresis was performed on samples from PGPR-treated tobacco plants. Our results showed that chlorophyll a/b binding proteins were significantly up-regulated, and total chlorophyll content was also increased. Our findings indicate the potential benefits of using Bacillus sp. JS as a growth-promoting factor in agricultural practice, and highlight the need for further research to explore these benefits.

  9. Plant-Microbe Communication Enhances Auxin Biosynthesis by a Root-Associated Bacterium, Bacillus amyloliquefaciens SQR9.

    Science.gov (United States)

    Liu, Yunpeng; Chen, Lin; Zhang, Nan; Li, Zunfeng; Zhang, Guishan; Xu, Yu; Shen, Qirong; Zhang, Ruifu

    2016-04-01

    Mechanisms by which beneficial rhizobacteria promote plant growth include tryptophan-dependent indole-3-acetic acid (IAA) synthesis. The abundance of tryptophan in the rhizosphere, however, may influence the level of benefit provided by IAA-producing rhizobacteria. This study examined the cucumber-Bacillus amyloliquefaciens SQR9 system and found that SQR9, a bacterium previously shown to enhance the growth of cucumber, increased root secretion of tryptophan by three- to fourfold. Using a split-root system, SQR9 colonization of roots in one chamber not only increased tryptophan secretion from the noninoculated roots but also increased the expression of the cucumber tryptophan transport gene but not the anthranilate synthesis gene in those roots. The increased tryptophan in isolated rhizosphere exudates was sufficient to support increased IAA production by SQR9. Moreover, SQR9 colonization of roots in one chamber in the split-root system resulted in sufficient tryptophan production by the other roots to upregulate SQR9 IAA biosynthesis genes, including a 27-fold increase in the indole-3-acetonitrilase gene yhcX during subsequent colonization of those roots. Deletion of yhcX eliminated SQR9-mediated increases in root surface area, likely by reducing IAA-stimulated lateral root growth. This study demonstrates a chemical dialogue between B. amyloliquefaciens and cucumber in which this communication contributes to bacteria-mediated plant-growth enhancement.

  10. Indigenous Pseudomonas spp. Strains from the Olive (Olea europaea L.) Rhizosphere as Effective Biocontrol Agents against Verticillium dahliae: From the Host Roots to the Bacterial Genomes

    Science.gov (United States)

    Gómez-Lama Cabanás, Carmen; Legarda, Garikoitz; Ruano-Rosa, David; Pizarro-Tobías, Paloma; Valverde-Corredor, Antonio; Niqui, José L.; Triviño, Juan C.; Roca, Amalia; Mercado-Blanco, Jesús

    2018-01-01

    The use of biological control agents (BCA), alone or in combination with other management measures, has gained attention over the past decades, driven by the need to seek for sustainable and eco-friendly alternatives to confront plant pathogens. The rhizosphere of olive (Olea europaea L.) plants is a source of bacteria with potential as biocontrol tools against Verticillium wilt of olive (VWO) caused by Verticillium dahliae Kleb. A collection of bacterial isolates from healthy nursery-produced olive (cultivar Picual, susceptible to VWO) plants was generated based on morphological, biochemical and metabolic characteristics, chemical sensitivities, and on their in vitro antagonistic activity against several olive pathogens. Three strains (PIC25, PIC105, and PICF141) showing high in vitro inhibition ability of pathogens' growth, particularly against V. dahliae, were eventually selected. Their effectiveness against VWO caused by the defoliating pathotype of V. dahliae was also demonstrated, strain PICF141 being the rhizobacteria showing the best performance as BCA. Genotypic and phenotypic traits traditionally associated with plant growth promotion and/or biocontrol abilities were evaluated as well (e.g., phytase, xylanase, catalase, cellulase, chitinase, glucanase activities, and siderophore and HCN production). Multi-locus sequence analyses of conserved genes enabled the identification of these strains as Pseudomonas spp. Strain PICF141 was affiliated to the “Pseudomonas mandelii subgroup,” within the “Pseudomonas fluorescens group,” Pseudomonas lini being the closest species. Strains PIC25 and PIC105 were affiliated to the “Pseudomonas aeruginosa group,” Pseudomonas indica being the closest relative. Moreover, we identified P. indica (PIC105) for the first time as a BCA. Genome sequencing and in silico analyses allowed the identification of traits commonly associated with plant-bacteria interactions. Finally, the root colonization ability of these olive

  11. Evaluation of plant growth promoting activity and heavy metal tolerance of psychrotrophic bacteria associated with maca (Lepidium meyenii Walp. rhizosphere

    Directory of Open Access Journals (Sweden)

    Paola Ortiz-Ojeda

    2017-05-01

    Full Text Available The high Andean plateau of Peru is known to suffer harsh environmental conditions. Acidic soils containing high amount of heavy metals due to mining activities and withstanding very low temperatures affect agricultural activities by diminishing crop quality and yield. In this context, plant growth promoting rhizobacteria (PGPR adapted to low temperatures and tolerant to heavy metals can be considered as an environment-friendly biological alternative for andean crop management. The aim of this work was to select and characterize psychrotrophic PGPR isolated from the rhizosphere of maca (Lepidium meyenii Walp. a traditional andean food crop. A total of 44 psychrotrophic strains isolated from 3 areas located in the Bombon plateu of Junin-Peru were tested for their PGPR characteristics like indole acetic acid (IAA production, phosphate solubilization and for their ability to improve seed germination. In addition, their capacity to grow in the presence of heavy metals like cadmium (Cd, lead (Pb, cobalt (Co and mercury (Hg was tested. Of the total number of strains tested, 12 were positive for IAA production at 22 °C, 8 at 12 °C and 16 at 6 °C. Phosphate solubilization activities were higher at 12 °C and 6 °C than at 22 °C. Red clover plant assays showed that 16 strains were capable to improve seed germination at 22 °C and 4 at 12 °C. Moreover, 11 strains showed tolerance to Cd and Pb at varying concentrations. This study highlight the importance of obtaining PGPRs to be used in high andean plateu crops that are exposed to low temperatures and presence of heavy metals on soil.

  12. Isolation of a potential biocontrol agent Paenibacillus polymyxa NSY50 from vinegar waste compost and its induction of host defense responses against Fusarium wilt of cucumber.

    Science.gov (United States)

    Du, Nanshan; Shi, Lu; Yuan, Yinghui; Sun, Jin; Shu, Sheng; Guo, Shirong

    2017-09-01

    Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (FOC) is one of the major destructive soil-borne diseases infecting cucumber. In this study, we screened 60 target strains isolated from vinegar waste compost, from which 10 antagonistic strains were identified to have the disease suppression capacity of bio-control agents. The 16S rDNA gene demonstrated that the biocontrol agents were Paenibacillus polymyxa (P. polymyxa), Bacillus amyloliquefaciens (B. amyloliquefaciens) and Bacillus licheniformis (B. licheniformis). Based on the results of antagonistic activity experiments and pot experiment, an interesting strain of P. polymyxa (named NSY50) was selected for further research. Morphological, physiological and biochemical characteristics indicated that this strain was positive for protease and cellulase and produced indole acetic acid (22.21±1.27μg mL -1 ) and 1-aminocyclopropane-1-carboxylate deaminase (ACCD). NSY50 can significantly up-regulate the expression level of defense related genes PR1 and PR5 in cucumber roots at the early stages upon challenge with FOC. However, the gene expression levels of a set of defense-related genes, such as the plant nucleotide-binding site (NBS)-leucine-rich repeat (LRR) gene family (e.g., Csa001236, Csa09775, Csa018159), 26kDa phloem protein (Csa001568, Csa003306), glutathione-S-transferase (Csa017734) and phenylalanine ammonia-lyase (Csa002864) were suppressed by pretreatment with NSY50 compared with the single challenge with FOC after nine days of inoculation. Of particular interest was the reduced expression of these genes at disease progression stages, which may be required for F. oxysporum dependent necrotrophic disease development. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Catecholate-siderophore produced by As-resistant bacterium effectively dissolved FeAsO_4 and promoted Pteris vittata growth

    International Nuclear Information System (INIS)

    Liu, Xue; Yang, Guang-Mei; Guan, Dong-Xing; Ghosh, Piyasa; Ma, Lena Q.

    2015-01-01

    The impact of siderophore produced by arsenic-resistant bacterium Pseudomonas PG12 on FeAsO_4 dissolution and plant growth were examined. Arsenic-hyperaccumulator Pteris vittata was grown for 7 d in 0.2-strength Fe-free Hoagland solution containing FeAsO_4 mineral and PG12-siderophore or fungal-siderophore desferrioxamine B (DFOB). Standard siderophore assays indicated that PG12-siderophore was catecholate-type. PG12-siderophore was more effective in promoting FeAsO_4 dissolution, and Fe and As plant uptake than DFOB. Media soluble Fe and As in PG12 treatment were 34.6 and 3.07 μM, 1.6- and 1.4-fold of that in DFOB. Plant Fe content increased from 2.93 to 6.24 g kg"−"1 in the roots and As content increased from 14.3 to 78.5 mg kg"−"1 in the fronds. Besides, P. vittata in PG12 treatment showed 2.6-times greater biomass than DFOB. While P. vittata fronds in PG12 treatment were dominated by AsIII, those in DFOB treatment were dominated by AsV (61–77%). This study showed that siderophore-producing arsenic-resistant rhizobacteria may have potential in enhancing phytoremediation of arsenic-contaminated soils. - Graphical abstract: As-induced root exudate phytate enhanced FeAsO_4 dissolution, and As uptake and plant growth of Pteris vittata. Display Omitted - Highlights: • Arsenic-resistant rhizobacterium Pseudomonas PG12 was from rhizosphere of As-hyperaccumulator Pteris vittata. • PG12 was effective in producing catecholate-type siderophore with high affinity with Fe. • PG12-produced siderophore increased Fe and As uptake and growth in P. vittata. - Siderophores produced by arsenic-resistant bacteria were effective in solubilizing FeAsO_4 mineral and enhancing plant growth of As-hyperaccumulator Pteris vittata.

  14. Use of response surface methodology to evaluate the effect of metal ions (Ca2+, Ni2+, Mn2+, Cu2+) on production of antifungal compounds by Paenibacillus polymyxa.

    Science.gov (United States)

    Raza, Waseem; Hongsheng, Wu; Qirong, Shen

    2010-03-01

    The effects of four metal ions (Ca(2+), Ni(2+), Mn(2+) and Cu(2+)) were evaluated on growth and production of antifungal compounds by Paenibacillus polymyxa SQR-21 and a quadratic predictive model was developed using response surface methodology (RSM). The results revealed, Mn(2+) and Ni(2+) showed most positive synergistic interactive affect on production of antifungal compounds followed by the positive interactive synergistic affect of Cu(2+) and Ni(2+) and then Mn(2+) and Cu(2+). While the interactive effect of Ca(2+) with all other three metals inhibited the production of antifungal compounds. The Mn(2+) (P=0.0384), Ni(2+) (P=0.0004) and Cu(2+) (P=0.0117) significantly affected the production of antifungal compounds while the effect of Ca(2+) (P=0.1851) was less significant. The maximum growth (OD(600)=1.55) was obtained at 500 (0), 125 (0), 100 (-2) and 37.5 (0) microM levels and the maximum size of inhibition zone (31 mm) was measured at 400 (-1), 150 (1), 400 (1) and 25 microM (-1) levels of Ca(2+), Mn(2+), Ni(2+) and Cu(2+), respectively. The RSM model provided an easy and effective way to determine the interactive effect of metal ions on production of antifungal compounds by P. polymyxa SQR-21 so that optimum media recipes can be developed to produce maximum amounts of antifungal compounds under laboratory and commercial fermentation conditions. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  15. The distribution of Paenibacillus larvae spores in adult bees and honey and larval mortality, following the addition of American foulbrood diseased brood or spore-contaminated honey in honey bee (Apis mellifera) colonies.

    Science.gov (United States)

    Lindström, Anders; Korpela, Seppo; Fries, Ingemar

    2008-09-01

    Within colony transmission of Paenibacillus larvae spores was studied by giving spore-contaminated honey comb or comb containing 100 larvae killed by American foulbrood to five experimental colonies respectively. We registered the impact of the two treatments on P. larvae spore loads in adult bees and honey and on larval mortality by culturing for spores in samples of adult bees and honey, respectively, and by measuring larval survival. The results demonstrate a direct effect of treatment on spore levels in adult bees and honey as well as on larval mortality. Colonies treated with dead larvae showed immediate high spore levels in adult bee samples, while the colonies treated with contaminated honey showed a comparable spore load but the effect was delayed until the bees started to utilize the honey at the end of the flight season. During the winter there was a build up of spores in the adult bees, which may increase the risk for infection in spring. The results confirm that contaminated honey can act as an environmental reservoir of P. larvae spores and suggest that less spores may be needed in honey, compared to in diseased brood, to produce clinically diseased colonies. The spore load in adult bee samples was significantly related to larval mortality but the spore load of honey samples was not.

  16. Identification and functional analysis of the S-layer protein SplA of Paenibacillus larvae, the causative agent of American Foulbrood of honey bees.

    Directory of Open Access Journals (Sweden)

    Lena Poppinga

    Full Text Available The gram-positive, spore-forming bacterium Paenibacillus larvae is the etiological agent of American Foulbrood (AFB, a globally occurring, deathly epizootic of honey bee brood. AFB outbreaks are predominantly caused by two genotypes of P. larvae, ERIC I and ERIC II, with P. larvae ERIC II being the more virulent genotype on larval level. Recently, comparative proteome analyses have revealed that P. larvae ERIC II but not ERIC I might harbour a functional S-layer protein, named SplA. We here determine the genomic sequence of splA in both genotypes and demonstrate by in vitro self-assembly studies of recombinant and purified SplA protein in combination with electron-microscopy that SplA is a true S-layer protein self-assembling into a square 2D lattice. The existence of a functional S-layer protein is novel for this bacterial species. For elucidating the biological function of P. larvae SplA, a genetic system for disruption of gene expression in this important honey bee pathogen was developed. Subsequent analyses of in vivo biological functions of SplA were based on comparing a wild-type strain of P. larvae ERIC II with the newly constructed splA-knockout mutant of this strain. Differences in cell and colony morphology suggest that SplA is a shape-determining factor. Marked differences between P. larvae ERIC II wild-type and mutant cells with regard to (i adhesion to primary pupal midgut cells and (ii larval mortality as measured in exposure bioassays corroborate the assumption that the S-layer of P. larvae ERIC II is an important virulence factor. Since SplA is the first functionally proven virulence factor for this species, our data extend the knowledge of the molecular differences between these two genotypes of P. larvae and contribute to explaining the observed differences in virulence. These results present an immense advancement in our understanding of P. larvae pathogenesis.

  17. Bacillus species enhance growth parameters of chickpea (Cicer arietinum L.) in chromium stressed soils.

    Science.gov (United States)

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2010-11-01

    Pollution of the agricultural land by the toxic chromium is a global threat that has accelerated dramatically since the beginning of industrial revolution. Toxic chromium affects both the microbial diversity as well as reduces the growth of the plants. Understanding the effect of the chromium reducing and plant growth promoting rhizobacteria on chickpea crop will be useful. Chromium reducing and plant growth promoting Bacillus species PSB10 significantly improved growth, nodulation, chlorophyll, leghaemoglobin, seed yield and grain protein of chickpea crop grown in the presence of different concentrations of chromium compared to the plants grown in the absence of bio-inoculant. The strain also reduced the uptake of chromium in roots, shoots and grains of chickpea crop compared to plants grown in the absence of bio-inoculant. This study thus suggested that the Bacillus species PSB10 due to its intrinsic abilities of growth promotion and attenuation of the toxic effects of chromium could be exploited for remediation of chromium from chromium contaminated sites. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Differential effects of organic compounds on cucumber damping-off and biocontrol activity of antagonistic bacteria

    DEFF Research Database (Denmark)

    Li, Bin; Ravnskov, Sabine; Guanlin, X.

    2011-01-01

    The influence of the organic compounds tryptic soy broth, cellulose, glucose and chitosan on cucumber damping-off caused by Pythium aphanidermatum and biocontrol efficacy of the biocontrol agents (BCAs) Paenibacillus macerans and P. polymyxa were examined in a seedling emergence bioassay. Results...... showed that the organic compounds differentially affected both pathogen and BCAs. Tryptic soy broth, glucose and chitosan increased Pythium damping-off of cucumber, compared to the control treatment without organic compounds, whereas cellulose had no effect. Both Paenibacillus species had biocontrol...

  19. Desert farming benefits from microbial potential in arid soils and promotes diversity and plant health.

    Directory of Open Access Journals (Sweden)

    Martina Köberl

    Full Text Available BACKGROUND: To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. METHODOLOGY/PRINCIPAL FINDINGS: We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt. Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90, and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37% than in the desert (11%. Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%; disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. CONCLUSIONS/SIGNIFICANCE: After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural

  20. Evaluating the influence of plant growth-promoting rhizobacteria as a bio-fertilizer under different fertility sources

    Science.gov (United States)

    Chemical fertilizers are being extensively used to satisfy the increasing demand for food. However, utilization of chemical fertilizers can be costly and over application for ensuring crop productivity may lead to environmental problems. As a result, interest in using bio-fertilizers to improve soil...

  1. Characterization of the Paenibacillus beijingensis DSM 24997 GtfD and its glucan polymer products representing a new glycoside hydrolase 70 subfamily of 4,6-α-glucanotransferase enzymes.

    Directory of Open Access Journals (Sweden)

    Joana Gangoiti

    Full Text Available Previously we have reported that the Gram-negative bacterium Azotobacter chroococcum NCIMB 8003 uses the 4,6-α-glucanotransferase GtfD to convert maltodextrins and starch into a reuteran-like polymer consisting of (α1→4 glucan chains connected by alternating (α1→4/(α1→6 linkages and (α1→4,6 branching points. This enzyme constituted the single evidence for this reaction and product specificity in the GH70 family, mostly containing glucansucrases encoded by lactic acid bacteria (http://www.CAZy.org. In this work, 4 additional GtfD-like proteins were identified in taxonomically diverse plant-associated bacteria forming a new GH70 subfamily with intermediate characteristics between the evolutionary related GH13 and GH70 families. The GtfD enzyme encoded by Paenibacillus beijingensis DSM 24997 was characterized providing the first example of a reuteran-like polymer synthesizing 4,6-α-glucanotransferase in a Gram-positive bacterium. Whereas the A. chroococcum GtfD activity on amylose resulted in the synthesis of a high molecular polymer, in addition to maltose and other small oligosaccharides, two reuteran-like polymer distributions are produced by P. beijingensis GtfD: a high-molecular mass polymer and a low-molecular mass polymer with an average Mw of 27 MDa and 19 kDa, respectively. Compared to the A. chroooccum GtfD product, both P. beijingensis GtfD polymers contain longer linear (α1→4 sequences in their structure reflecting a preference for transfer of even longer glucan chains by this enzyme. Overall, this study provides new insights into the evolutionary history of GH70 enzymes, and enlarges the diversity of natural enzymes that can be applied for modification of the starch present in food into less and/or more slowly digestible carbohydrate structures.

  2. Avaliação de populações de possíveis rizobactérias em solos sob espécies florestais Evaluation of possible rhizobacteria populations in soils under forest species

    Directory of Open Access Journals (Sweden)

    Rodrigo Matheus Pereira

    2008-10-01

    Full Text Available Embora estudos recentes relatem a utilização de RCPC (Rizobactérias Promotoras de Crescimento de Plantas no Brasil, raríssimos trabalhos avaliam a presença natural dessas espécies bacterianas no solo. O objetivo deste trabalho foi avaliar a ocorrência de RPCP em duas amostras de solo sob diferentes tipos de manejo, através da construção e do seqüenciamento de bibliotecas de DNA metagenômico. Utilizaram-se oligonucleotídeos específicos para amplificação da região hipervariável do espaço intergênico dos genes ribossomais 16S-23S de DNA extraído de diferentes solos, sob Eucalyptus sp. e sob mata. Os fragmentos obtidos foram inseridos em vetor e clonados. As bibliotecas geraram 495 clones, que foram seqüenciados e identificados através de comparações realizadas pelo software Blast. O solo sob Eucalyptus sp. apresentou maior número de RPCP do que sob mata. Os filos Actinobacteria e Proteobacteria eram maiores no solo sob Eucalyptus sp., estando o filo Firmicutes ausente no solo sob mata. Somente oito espécies diferentes de RPCP foram detectadas: Bacillus subtilis, Bacillus megaterium, Bradyrhizobium japonicum, Bradyrhizobium elkanii, Bradyrhizobium sp., Frankia sp., Pseudomonas fluorescens e Pseudomonas gladioli. O trabalho forneceu valiosos dados sobre a presença de RPCP em solos com espécies florestais e sua possível utilização em reflorestamentos, assim como para o melhor conhecimento desses microrganismos nos solos do Brasil.Although new studies describe the use of PGPR (Plant Growth-Promoting Rhizobacteria in Brazil, they rarely evaluate the natural existence of these bacterial species in the soil. The objective of this study was to evaluate PGPR in two samples under different use types, one with native forest and the other with eucalyptus, through construction and sequencing of a metagenomic DNA library. Using specific probes from the internally transcribed region of 16S-23S rRNA genes, fragments of PCR products

  3. PGPRs and nitrogen-fixing legumes: a perfect team for efficient Cd phytoremediation?

    Directory of Open Access Journals (Sweden)

    María Teresa eGómez-Sagasti

    2015-02-01

    Full Text Available Cadmium (Cd is a toxic, biologically non-essential and highly mobile metal that has become an increasingly important environmental hazard to both wildlife and humans. In contrast to conventional remediation technologies, phytoremediation based on rhizobia-legume symbiosis has emerged as an inexpensive decontamination alternative which also revitalize contaminated soils due to the role of legumes in nitrogen cycling. In recent years, there is growing interest in understanding symbiotic rhizobia-legume relationship and its interactions with Cd. The aim of the present review is to provide a comprehensive picture of the main effects of Cd in N2-fixing leguminous plants and the benefits of exploiting this symbiosis together with plant growth promoting rhizobacteria (PGPRs to boost an efficient reclamation of Cd-contaminated soils.

  4. What do health-promoting schools promote?

    DEFF Research Database (Denmark)

    Simovska, Venka

    2012-01-01

    -promotion interventions. Directly or indirectly the articles reiterate the idea that health promotion in schools needs to be linked with the core task of the school – education, and to the values inherent to education, such as inclusion, democracy, participation and influence, critical literacy and action competence......Purpose – The editorial aims to provide a brief overview of the individual contributions to the special issue, and a commentary positioning the contributions within research relating to the health-promoting schools initiative in Europe. Design/methodology/approach – The members of the Schools...... for Health in Europe Research Group were invited to submit their work addressing processes and outcomes in school health promotion to this special issue of Health Education. Additionally, an open call for papers was published on the Health Education web site. Following the traditional double blind peer...

  5. Vertical zonation and seed germination indices of chromium resistant cellulolytic and nitrogen fixing bacteria from a chronically metal exposed land area

    International Nuclear Information System (INIS)

    Aslam, S.; Qazi, J.I.

    2014-01-01

    Twenty eight cellulolytic and 25 nitrogen fixing bacteria were isolated from 20, 40 and 60 cm depths of the chromium contaminated land area. The cellulolytic as well as nitrogen fixing microbial communities in soil profiles were dominated by genus Bacillus. More diverse nitrogen fixing bacterial isolates belonging to different genera Paenibacillus, Corynebacterium and Pseudomonas were observed as compared to cellulolytic bacterial community. Majority of the cellulolytic bacteria were found inhabitants of 20 cm soil layer while 40 cm depth was the preferred zone for the nitrogen fixing bacteria. Screening of the bacterial isolates for chromium resistance showed that isolates designated as ASK15 and ASK16 were able to resist up to 1800 mg/l of chromium while the nitrogen fixing isolates which offered a maximum resistant level up to 1650 mg/l of chromium were ASNt10 and ASNS13. Nitrogen fixing isolates enhanced seed germination by 33% and expressed efficient nitrogenase activity up to 0.80 (C/sub 2/H/sub 2/ nmol/ml/hr). Growth promoting assay proved ASNt10 a potential isolate which produced 90 meu g/ml of indoleacetic acid (IAA). Though cellulolytic isolates did not affect seed germination, a significant influence on root length similar to that of ASNt10 and ASNS13 with nearly 5-fold increase in comparison with uninoculated control was observed. The isolates ASK15, ASK16 were identified as Bacillus cereus while ASNt10 and ASNS13 as Paenibacillus barcinonensis and Bacillus megaterium, respectively. (author)

  6. Dégradation du Xyloglucane par les souches de Paenibacillus polymyxa isolées de la rhizosphère du blé dur sur des sols Algériens

    Directory of Open Access Journals (Sweden)

    Souad Athmani-Guemouri

    2014-06-01

    Full Text Available Les espèces du genre Paenibacillus secrètent une variété d’enzymes extracellulaires parmi lesquelles figurent plusieurs types de β glucanases. Nous avons réalisé un test de dégradation du xyloglucane sur 29 souches isolées par immunopiégeage et identifiées à P. polymyxa par le système API50CHB. Ces souches ont été groupées en séries qui correspondent aux échantillons de sols à partir desquels elles avaient été isolées. Des souches de références et des souches type E. coli ont été intégrées lors de cette étude pour comparer leur activité à celles des souches isolées des sols d’Algérie. Les résultats de cette recherche montrent que toutes les souches de P. polymyxa sont capables de dégrader le xyloglucane, alors que les souches des espèces testées n’ont pas cette activité. Ces résultats semblent suggérer que cette propriété est partagée par tous les P. polymyxa et qu’elle n’est pas liée au sol d’origine de nos souches ni à l’ancienneté de culture du blé de ces sols. Nous avons également montré que la xyloglucanase fait partie du pool d’enzymes inductibles qui ne sont normalement présentes qu’à l’état de traces dans les bactéries, et dont la synthèse est amplifiée considérablement en présence de leur substrat.

  7. [Diversity of Bacillus species inhabiting on the surface and endophyte of lichens collected from Wuyi Mountain].

    Science.gov (United States)

    Ge, Cibin; Liu, Bo; Che, Jianmei; Chen, Meichun; Liu, Guohong; Wei, Jiangchun

    2015-05-04

    The present work reported the isolation, identification and diversity of Bacillus species colonizing on the surface and endophyte in lichens collected from Wuyi Mountain. Nine lichen samples of Evernia, Stereocaulon, Menegazzia and other 6 genera belonging to 7 families were collected from Wuyi mountain nature reserve. The bacillus-like species colonizing on the surface and endophyte in these lichens were isolated and identified by 16S rRNA gene sequence analysis. There was no bacillus-like species isolated from Evernia, Ramalina and Lecarona. A total of 34 bacillus-like bacteria were isolated from another 6 lichen samples. These bacteria were identified as 24 species and were classified into Bacillus, Paenibacillus, Brevibacillus, Lysinibacillus and Viridiibacillus. Paenibacillus and Bacillus are the dominant genera, and accounting for 41. 2% and 35. 3% of all isolated bacteria respectively. Brevibacillus, Lysinibacillus and Viridiibacillu were first reported being isolated from lichens. There were different species and quantity of bacillus colonizing on the surface and endophyte in different lichens. The quantity of bacillus colonizing on the surface of Physcia was more than 3.85 x 10(6) cfu/g and was the largest in the isolated bacteria, while the species of bacillus colonizing on the surface and endophyte in Stereocaulon was the most abundant. Most of the isolated bacteria were colonizing on (in) one lichen genera, but Paenibacillus taichungensis, Paenibacillus odorifer, Brevibacillus agri, Lysinibacillus xylanilyticus was respectively colonizing on (in) 2-3 lichen genera and Bacillus mycoides was colonizing on (in) Menegazzia, Cladonia Physcia, and Stereocaulon. There are species and quantity diversity of bacillus colonizing on (in) lichens.

  8. Biocidal properties of maltose reduced silver nanoparticles against American foulbrood diseases pathogens.

    Science.gov (United States)

    Çulha, Mustafa; Kalay, Şaban; Sevim, Elif; Pinarbaş, Müberra; Baş, Yıldız; Akpinar, Rahşan; Karaoğlu, Şengül Alpay

    2017-12-01

    Bee disease caused by spore-forming Paenibacillus larvae and Paenibacillus alvei is a serious problem for honey production. Thus, there is an ongoing effort to find an effective agent that shows broad biocidal activity with minimal environmental hazard. In this study, the biocidal effect of maltose reduced silver nanoparticles (AgNPs) is evaluated against American foulbrood and European foulbrood pathogens. The results demonstrate that the maltose reduced AgNPs are excellent short and long-term biocides against P. larvae isolates. The long-term effect suggests that the Ag + ions are released from the AgNPs with increasing time in a controlled manner.

  9. A screening method for β-glucan hydrolase employing Trypan Blue-coupled β-glucan agar plate and β-glucan zymography.

    Science.gov (United States)

    Park, Chang-Su; Yang, Hee-Jong; Kim, Dong-Ho; Kang, Dae-Ook; Kim, Min-Soo; Choi, Nack-Shick

    2012-06-01

    A new screening method for β-(1,3-1,6) glucan hydrolase was developed using a pure β-glucan from Aureobaisidum pullulans by zymography and an LB-agar plate. Paenibacillus sp. was screened as a producer a β-glucan hydrolase on the Trypan Blue-coupled β-glucan LB-agar plate and the activity of the enzyme was analyzed by SDS-β-glucan zymography. The β-glucan was not hydrolyzed by Bacillus spp. strains, which exhibit cellulolytic activity on CMC zymography. The gene, obtaining by shotgun cloning and encoding the β-glucan hydrolase of Paenibacillus sp. was sequenced.

  10. Response of Paenibacillus polymyxa to iron: alternations in cellular chemical composition and the production of fusaricidin type antimicrobial compounds

    Directory of Open Access Journals (Sweden)

    Waseem Raza

    2010-10-01

    Full Text Available In this work, growth, cellular chemical composition and production of fusaricidin type antimicrobial compounds by P. polymyxa SQR-21 were compared in tryptone broth supplemented with four concentrations of iron (25, 50, 100 and 200 µM. The data revealed that the growth of P. polymyxa SQR-21 was increased by 3-8% with the increase in concentration of ferric ion (Fe3+. The production of fusaricidin type compounds was increased by 33-49% only up to 50 µM Fe3+ and the highest level of Fe3+ was inhibitory. Increase in the liquid culture Fe3+concentration increased the intracellular protein (2%, intracellular carbohydrate (14%, extracellular protein (7% and polysaccharide contents (18% while the intracellular lipid contents were increased (11% only up to 50 µM Fe3+. In addition, the regulatory effects of Fe3+ were also reflected by the increase in total RNA contents and relative expression of the fusaricidin synthetase gene (FusA by 3-13 and 35-56%, respectively, up to 50 µM Fe3+, after that a continuous decrease was observed.Tipo compostos do fusaricidin do produto das tensões do polymyxa de Paenibacillus que é ativo de encontro a uma variedade larga das bactérias e de fungos gram-positive. O crescimento, a composição química celular e a produção do fusaricidin datilografam compostos antimicrobial pelo P. o polymyxa SQR-21 foi comparado no caldo de carne do tryptone suplementado com as quatro concentrações (25, µM 50, 100 e 200 do ferro. Os dados revelaram que o crescimento do P. o polymyxa foi aumentado por 3-8% com o aumento na concentração do íon férrico (Fe3+ e o tipo produção do fusaricidin dos compostos foi aumentado 33-49% somente até 50 pelo µM Fe3+ quando o nível o mais elevado de Fe3+ era inhibitory. O aumento na concentração de Fe3+ na cultura líquida aumentou a proteína intracellular (2% e os índices de hidrato de carbono (14% e a proteína extracellular (7% e os índices do polysaccharide (18% quando os

  11. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Directory of Open Access Journals (Sweden)

    Yi-Ru Lai

    2016-10-01

    Full Text Available Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

  12. Health Promotion Education

    DEFF Research Database (Denmark)

    Lehn-Christiansen, Sine

    The paper discusses the implications of health promotion in education. The paper is based on my PhD project entitled “Health promotion education seen through a power/knowledge and subjectification perspective” (in prep). The PhD project explores how professional health promotion skills are concei......The paper discusses the implications of health promotion in education. The paper is based on my PhD project entitled “Health promotion education seen through a power/knowledge and subjectification perspective” (in prep). The PhD project explores how professional health promotion skills...

  13. Potencial de rizobactérias no controle de Fusarium solani (Mart. Sacc. em pepino (Cucumis sativum L. Potential of rhizobacteria in the control of Fusarium solani (Mart. Sacc. in cucumber (Cucumis sativum L.

    Directory of Open Access Journals (Sweden)

    I S. de Melo

    1995-08-01

    Full Text Available Rizobactérias, isoladas da rizosfera de diferentes hospedeiros foram selecionadas in vitro quanto ao antagonismo contra Fusarium solam agente causai da podridão radicular. In vitro, foram selecionadas 18 bactérias isoladas da rizosfera de plantas sadias de pepino e, destas, somente três foram eficientes em inibir consideravelmente o crescimento micelial do patógeno. Dois isolados de Bacillus subtilis e dois de Pseudomonas sp., antagônicos a outros fungos fitopatogênicos foram incluidos nos testes, os quais mostraram-se capazes de antagonizar F. solani. Em condições de casa-de-vegetação, B. subtilis, linhagem 0G, controlou totalmente o patógeno em todos os ensaios realizados. Promoção do crescimento de plantas foi verificada pela inoculação com linhagens 0G (B. subtilis, St. Barb. e CBPN (Pseudomonas sp.Rhizobacteria, isolated from the rhizosphere of different hosts were selected in vitro, based on the antagonism against Fusarium solani, agent of root rot. In vitro, 18 bacterias were selected from rhizosphere of healthy plants of cucumber and, from those, only three were efficient in inhibiting the micelial growth of the pathogen. In these tests two isolates of Bacillus subtilis (0G and 5G, and two of Pseudomonas (CBPN and St Barb., antagonistic to some pathogenic fungi, were included. These bolates also inhibited the growth of F solani. The bolate OG of B. subtilis reduced significantly the root rot of cucumber. Beneficial effects were obtained with the bolates St Barb., 0G and CBPN in relation to plant growth.

  14. Perceptions of health promoters about health promotion ...

    African Journals Online (AJOL)

    2013-02-11

    Feb 11, 2013 ... regarding a health promotion programme for families with ... to contribute to high rates of not going to school (ibid. ... sector in order, amongst other objectives, to prevent health ... exercise and mental health promotion must be incorporated ..... (2009:141) identified ignorance and misconception about the.

  15. Health Promotion

    DEFF Research Database (Denmark)

    Povlsen, Lene; Borup, I.

    2015-01-01

    and Adolescent Health Promotion', Salutogenesis - from theory to practice' and Health, Stress and Coping'. More than half of all doctoral theses undertaken at NHV during these years had health promotion as their theme. As a derivative, the Nordic Health Promotion Research Network (NHPRN) was established in 2007......In 1953 when the Nordic School of Public Health was founded, the aim of public health programmes was disease prevention more than health promotion. This was not unusual, since at this time health usually was seen as the opposite of disease and illness. However, with the Ottawa Charter of 1986......, the World Health Organization made a crucial change to view health not as a goal in itself but as the means to a full life. In this way, health promotion became a first priority and fundamental action for the modern society. This insight eventually reached NHV and in 2002 - 50 years after the foundation...

  16. SPORT PROMOTION STRATEGIES

    Directory of Open Access Journals (Sweden)

    Alexandru Lucian MIHAI

    2013-10-01

    Full Text Available In sport marketing, the word promotion covers a range of interrelated activities. All of these activities are designed to attract attention, stimulate the interest and awareness of consumers, and of course, encourage them to purchase a sport product. Promotion is about communicating with and educating consumers. The purpose of a sport promotional strategy is to build brand loyalty and product credibility, develop image, and position the brand. A promotional strategy is similar to a marketing strategy, but the promotional strategy seeks short-term objectives, both direct and indirect. Promotional objectives usually include increased sales, stimulate impulse buying, raise customer traffic, and present and reinforce image. It also provides information about products and services, publicizes new stores or websites, and creates and enhances customer satisfaction.

  17. Algal sludge from Taihu Lake can be utilized to create novel PGPR-containing bio-organic fertilizers.

    Science.gov (United States)

    Zhang, Miao; Li, Rong; Cao, Liangliang; Shi, Juanjuan; Liu, Hongjun; Huang, Yan; Shen, Qirong

    2014-01-01

    Large amounts of refloated algal sludge from Taihu Lake result in secondary environmental pollution due to annual refloatation. This study investigated the possibility to produce bio-organic fertilizer (BIO) using algal sludge as a solid-state fermentation (SSF) medium. Results showed that addition of algal sludge contributed to efficient SFF by a plant growth-promoting rhizobacteria (PGPR) strain SQR9 and improved the nutrient contents in the novel BIO. The optimum water content and initial inoculation size were 45% and 5%, respectively. After 6 days of SSF, the biomass of strain SQR9 was increased to a cell density of more than 5 × 10(7) CFU g(-1). Microcystins were rapidly degraded, and a high germination index value was observed. Plant growth experiments showed that the produced BIO efficiently promoted plant growth. Additional testing showed that the novel SSF process was also suitable for other PGPR strains. This study provides a novel way of high-value utilization of algal sludge from Taihu Lake by producing low-cost but high-quality BIOs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The study on Egr-1 promoter which is radioactive promoter

    International Nuclear Information System (INIS)

    Zhang Chunzhi; Guo Yang; Lv Zhonghong

    2006-01-01

    Radiogenetic therapy is a heated reaseach on oncotherapy. Early growth response gene-1 (Egr-1) gene promoter is a probably means in radiogenetic therapy. The article review studying on Egr-1 gene promoter and constructing regulating gene expressing system by radiation-inducible Egr-1 gene promoter. (authors)

  19. Radiation promotive concept

    International Nuclear Information System (INIS)

    Shebaita, M.K.

    1975-01-01

    The concept of radiation promotion was proposed in this study. The proposal of this concept was dependent upon stimulation in growth weight of survived chicks when fertile eggs were exposed to 60 Co gamma radiation. It was found that female chick (Promotive Sex) responded to this proposal concept rather than the male. Moreover, the dose level of 640 rads was found to be the Promotive Dose. It is important before applying ionizing radiation as a growth promotive to take into consideration whether you want increasing egg or meat production, as meat promotion in layers breed is bound to decrease egg production. (orig.) [de

  20. Promoting Health in Early Childhood Environments: A Health-Promotion Approach

    Science.gov (United States)

    Minniss, Fiona Rowe; Wardrope, Cheryl; Johnston, Donni; Kendall, Elizabeth

    2013-01-01

    This paper investigates the mechanisms by which a health-promotion intervention might influence the health-promoting behaviours of staff members working in early childhood centres. The intervention was an ecological health-promotion initiative that was implemented within four early childhood centres in South-East Queensland, Australia. In-depth,…

  1. Promoting preschool reading

    OpenAIRE

    Istenič, Vesna

    2013-01-01

    The thesis titled Promoting preschool reading consists of a theoretiral and an empirical part. In the theoretical part I wrote about reading, the importance of reading, types of reading, about reading motivation, promoting reading motivation, internal and external motivation, influence of reading motivation on the child's reading activity, reading and familial literacy, the role of adults in promotion reading literacy, reading to a child and promoting reading in pre-school years, where I ...

  2. iTRAQ-based proteomic analysis of LI-F type peptides produced by Paenibacillus polymyxa JSa-9 mode of action against Bacillus cereus.

    Science.gov (United States)

    Han, Jinzhi; Gao, Peng; Zhao, Shengming; Bie, Xiaomei; Lu, Zhaoxin; Zhang, Chong; Lv, Fengxia

    2017-01-06

    LI-F type peptides (AMP-jsa9) produced by Paenibacillus polymyxa JSa-9 are a group of cyclic lipodepsipeptide antibiotics that exhibit a broad antimicrobial spectrum against Gram-positive bacteria and filamentous fungi, especially Bacillus cereus and Fusarium moniliforme. In this study, to better understand the antibacterial mechanism of AMP-jsa9 against B. cereus, the ultrastructure of AMP-jsa9-treated B. cereus cells was observed by both atomic force microscopy and transmission electron microscopy, and quantitative proteomic analysis was performed on proteins extracted from treated and untreated bacterial cells by using isobaric tag for relative and absolute quantitation (iTRAQ) labeling and LC-MS/MS analysis to access differentially expressed proteins. Furthermore, multiple experiments were conducted to validate the results of the proteomic analysis, including determinations of ATP, NAD (+) H, NADP (+) H, reactive oxygen species (ROS), the activities of catalase (CAT) and superoxide dismutase (SOD), and the relative expression of target genes by quantitative real-time PCR. Bacterial cells exposed to AMP-jsa9 showed irregular surfaces with bleb projections and concaves; we hypothesize that AMP-jsa9 penetrated the cell wall and was anchored on the cytoplasmic membrane and that ROS accumulated in the cell membrane after treatment with AMP-jsa9, modulating the bacterial membrane properties and increasing membrane permeability. Consequently, the blebs were formed on the cell wall by the impulsive force of the leakage of intercellular contents. iTRAQ-based proteomic analysis detected a total of 1317 proteins, including 176 differentially expressed proteins (75 upregulated (fold >2) and 101 downregulated (fold AMP-jsa9 action against B. cereus can be summarized as: (i) inhibition of bacterial sporulation, thiamine biosynthesis, energy metabolism, DNA transcription and translation, and cell wall biosynthesis, through direct regulation of protein levels; and (ii

  3. Streamlining Appointment, Promotion, and Tenure Procedures to Promote Early-Career Faculty Success.

    Science.gov (United States)

    Smith, Shannon B; Hollerbach, Ann; Donato, Annemarie Sipkes; Edlund, Barbara J; Atz, Teresa; Kelechi, Teresa J

    2016-01-01

    A critical component of the progression of a successful academic career is being promoted in rank. Early-career faculty are required to have an understanding of appointment, promotion, and tenure (APT) guidelines, but many factors often impede this understanding, thwarting a smooth and planned promotion pathway for professional advancement. This article outlines the steps taken by an APT committee to improve the promotion process from instructor to assistant professor. Six sigma's DMAIC improvement model was selected as the guiding operational framework to remove variation in the promotion process. After faculty handbook revisions were made, several checklists developed, and a process review rubric was implemented; recently promoted faculty were surveyed on satisfaction with the process. Faculty opinions captured in the survey suggest increased transparency in the process and perceived support offered by the APT committee. Positive outcomes include a strengthened faculty support framework, streamlined promotion processes, and improved faculty satisfaction. Changes to the APT processes resulted in an unambiguous and standardized pathway for successful promotion. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Analysis of Bacterial Diversity in Different Heavy Oil Wells of a Reservoir in South Oman with Alkaline pH

    Directory of Open Access Journals (Sweden)

    Biji Shibulal

    2018-01-01

    Full Text Available The identification of potential hydrocarbon utilizing bacteria is an essential requirement in microbial enhanced oil recovery (MEOR. Molecular approaches like proteomic and genomic characterization of the isolates are replacing the traditional method of identification with systemic classification. Genotypic profiling of the isolates includes fingerprint or pattern-based technique and sequence-based technique. Understanding community structure and dynamics is essential for studying diversity profiles and is challenging in the case of microbial analysis. The present study aims to understand the bacterial community composition from different heavy oil contaminated soil samples collected from geographically related oil well areas in Oman and to identify spore-forming hydrocarbon utilizing cultivable bacteria. V4 region of 16S rDNA gene was the target for Ion PGM™. A total of 825081 raw sequences were obtained from Ion torrent from all the 10 soil samples. The species richness and evenness were found to be moderate in all the samples with four main phyla, Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, the most abundant being Firmicutes. Bacillus sp. ubiquitously dominated in all samples followed by Paenibacillus, which was followed by Brevibacillus, Planococcus, and Flavobacterium. Principal Coordinate Analysis (PCoA and UPGMA dendrogram clustered the 10 soil samples into four main groups. Weighted UniFrac significance test determined that there was significant difference in the communities present in soil samples examined. It can be concluded that the microbial community was different in all the 10 soil samples with Bacillus and Paenibacillus sp. as predominating genus. The 16S rDNA sequencing of cultivable spore-forming bacteria identified the hydrocarbon utilizing bacteria as Bacillus and Paenibacillus sp. and the nucleotide sequences were submitted to NCBI GenBank under accession numbers KP119097–KP119115. Bacillus and

  5. Application of a redox gradostat reactor for assessing rhizosphere microorganism activity on lambda-cyhalothrin.

    Science.gov (United States)

    Peacock, T J; Mikell, A T; Moore, M T; Smith, S

    2014-03-01

    Bacterial activity on pesticides can lead to decreased toxicity or persistence in aquatic systems. Rhizosphere activity is difficult to measure in situ. To mimic rhizosphere properties of the soft rush, Juncus effusus, a single-stage gradostat reactor was developed to study cycling of lambda-cyhalothrin by rhizobacteria and the effects of Fe(III) and citrate, both common in wetland soil, on lambda-cyhalothrin degradation. Redox gradient changes, greater than ± 10 mV, were apparent within days 5-15 both in the presence and absence of ferric citrate. Through the production of a redox gradient (p < 0.05) by rhizobacteria and the ability to measure pesticide loss over time (p < 0.05), reactors were useful in expanding knowledge on this active environment.

  6. Promoter2.0: for the recognition of PolII promoter sequences

    DEFF Research Database (Denmark)

    Knudsen, Steen; Knudsen, Steen

    1999-01-01

    transcription start sites. On standardized test setsconsisting of human genomic DNA, the performance of Promoter2.0 compares well with other softwaredeveloped for the same purpose. Availability : Promoter2.0 is available as a Web server at http://www.cbs.dtu.dk/services/promoter/ Contact : steen@cbs.dtu.dk...

  7. Health-promoting schools

    DEFF Research Database (Denmark)

    Kwan, Stella Y L; Petersen, Poul Erik; Pine, Cynthia M

    2005-01-01

    Schools provide an important setting for promoting health, as they reach over 1 billion children worldwide and, through them, the school staff, families and the community as a whole. Health promotion messages can be reinforced throughout the most influential stages of children's lives, enabling...... them to develop lifelong sustainable attitudes and skills. Poor oral health can have a detrimental effect on children's quality of life, their performance at school and their success in later life. This paper examines the global need for promoting oral health through schools. The WHO Global School...... Health Initiative and the potential for setting up oral health programmes in schools using the health-promoting school framework are discussed. The challenges faced in promoting oral health in schools in both developed and developing countries are highlighted. The importance of using a validated...

  8. Proteus mirabilis alleviates zinc toxicity by preventing oxidative stress in maize (Zea mays) plants.

    Science.gov (United States)

    Islam, Faisal; Yasmeen, Tahira; Riaz, Muhammad; Arif, Muhammad Saleem; Ali, Shafaqat; Raza, Syed Hammad

    2014-12-01

    Plant-associated bacteria can have beneficial effects on the growth and health of their host. However, the role of plant growth promoting bacteria (PGPR), under metal stress, has not been widely investigated. The present study investigated the possible mandatory role of plant growth promoting rhizobacteria in protecting plants from zinc (Zn) toxicity. The exposure of maize plants to 50µM zinc inhibited biomass production, decreased chlorophyll, total soluble protein and strongly increased accumulation of Zn in both root and shoot. Similarly, Zn enhanced hydrogen peroxide, electrolyte leakage and lipid peroxidation as indicated by malondaldehyde accumulation. Pre-soaking with novel Zn tolerant bacterial strain Proteus mirabilis (ZK1) isolated zinc (Zn) contaminated soil, alleviated the negative effect of Zn on growth and led to a decrease in oxidative injuries caused by Zn. Furthermore, strain ZK1 significantly enhanced the activities of catalase, guaiacol peroxidase, superoxide dismutase and ascorbic acid but lowered the Proline accumulation in Zn stressed plants. The results suggested that the inoculation of Zea mays plants with P. mirabilis during an earlier growth period could be related to its plant growth promoting activities and avoidance of cumulative damage upon exposure to Zn, thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. What Is a Promotion?

    Science.gov (United States)

    Pergamit, Michael R.; Veum, Jonathan R.

    1999-01-01

    For a sample of young workers, "promotion" involved no change in position or duties; promotion was more likely for males than females and Whites than Blacks or Hispanics. Company training and prior promotions were important predictors. Promotion did not appear to have a direct impact on job satisfaction. (SK)

  10. Promoter2.0: for the recognition of PolII promoter sequences

    DEFF Research Database (Denmark)

    Knudsen, Steen; Knudsen, Steen

    1999-01-01

    Motivation : A new approach to the prediction of eukaryotic PolII promoters from DNA sequence takesadvantage of a combination of elements similar to neural networks and genetic algorithms to recognize a set ofdiscrete subpatterns with variable separation as one pattern: a promoter. The neural...... of optimization, the algorithm was able todiscriminate between vertebrate promoter and non-promoter sequences in a test set with a correlationcoefficient of 0.63. In addition, all five known transcription start sites on the plus strand of the completeadenovirus genome were within 161 bp of 35 predicted...

  11. Site-saturation engineering of lysine 47 in cyclodextrin glycosyltransferase from Paenibacillus macerans to enhance substrate specificity towards maltodextrin for enzymatic synthesis of 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G).

    Science.gov (United States)

    Han, Ruizhi; Liu, Long; Shin, Hyun-dong; Chen, Rachel R; Du, Guocheng; Chen, Jian

    2013-07-01

    In this work, the site-saturation engineering of lysine 47 in cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans was conducted to improve the specificity of CGTase towards maltodextrin, which can be used as a cheap and easily soluble glycosyl donor for the enzymatic synthesis of 2-O-D-glucopyranosyl-L-ascorbic acid (AA-2G) by CGTase. When using maltodextrin as glycosyl donor, four mutants K47F (lysine→ phenylalanine), K47L (lysine→ leucine), K47V (lysine→ valine) and K47W (lysine→ tryptophan) showed higher AA-2G yield as compared with that produced by the wild-type CGTase. The transformation conditions (temperature, pH and the mass ratio of L-ascorbic acid to maltodextrin) were optimized and the highest titer of AA-2G produced by the mutant K47L could reach 1.97 g/l, which was 64.2% higher than that (1.20 g/l) produced by the wild-type CGTase. The reaction kinetics analysis confirmed the enhan