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Sample records for beneficial bacterium azospirillum

  1. Azospirillum brasilense, a Beneficial Soil Bacterium: Isolation and Cultivation.

    Science.gov (United States)

    Alexandre, Gladys

    2017-11-09

    Bacteria of the genus Azospirillum comprise 15 species to date, with A. brasilense the best studied species in the genus. Azospirillum are soil bacteria able to promote the growth of plants from 113 species spanning 35 botanical families. These non-pathogenic and beneficial bacteria are ubiquitous in soils and inhabit the roots of diverse plants. These bacteria are microaerophilic, able to fix nitrogen under free-living conditions, motile, and able to navigate in gradients of various chemicals, including oxygen. These physiological traits are used to isolate these soil bacteria from soil and plant root samples, providing isolates that can be used for studying microbial physiology and plant growth promotion. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  2. 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.

  3. Fourier transform infrared spectroscopic study of intact cells of the nitrogen-fixing bacterium Azospirillum brasilense

    Science.gov (United States)

    Kamnev, A. A.; Ristić, M.; Antonyuk, L. P.; Chernyshev, A. V.; Ignatov, V. V.

    1997-06-01

    The data of Fourier transform infrared (FTIR) spectroscopic measurements performed on intact cells of the soil nitrogen-fixing bacterium Azospirillum brasilense grown in a standard medium and under the conditions of an increased metal uptake are compared and discussed. The structural FTIR information obtained is considered together with atomic absorption spectrometry (AAS) data on the content of metal cations in the bacterial cells. Some methodological aspects concerning preparation of bacterial cell samples for FTIR measurements are also discussed.

  4. Partial characterization of nif genes from the bacterium Azospirillum amazonense

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    D.P. Potrich

    2001-09-01

    Full Text Available Azospirillum amazonense revealed genomic organization patterns of the nitrogen fixation genes similar to those of the distantly related species A. brasilense. Our work suggests that A. brasilense nifHDK, nifENX, fixABC operons and nifA and glnB genes may be structurally homologous to the counterpart genes of A. amazonense. This is the first analysis revealing homology between A. brasilense nif genes and the A. amazonense genome. Sequence analysis of PCR amplification products revealed similarities between the amino acid sequences of the highly conserved nifD and glnB genes of A. amazonense and related genes of A. brasilense and other bacteria. However, the A. amazonense non-coding regions (the upstream activator sequence region and the region between the nifH and nifD genes differed from related regions of A. brasilense even in nitrogenase structural genes which are highly conserved among diazotrophic bacteria. The feasibility of the 16S ribosomal RNA gene-based PCR system for specific detection of A. amazonense was shown. Our results indicate that the PCR primers for 16S rDNA defined in this article are highly specific to A. amazonense and can distinguish this species from A. brasilense.

  5. Transcriptome analysis of the rhizosphere bacterium Azospirillum brasilense reveals an extensive auxin response.

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    Van Puyvelde, Sandra; Cloots, Lore; Engelen, Kristof; Das, Frederik; Marchal, Kathleen; Vanderleyden, Jos; Spaepen, Stijn

    2011-05-01

    The rhizosphere bacterium Azospirillum brasilense produces the auxin indole-3-acetic acid (IAA) through the indole-3-pyruvate pathway. As we previously demonstrated that transcription of the indole-3-pyruvate decarboxylase (ipdC) gene is positively regulated by IAA, produced by A. brasilense itself or added exogenously, we performed a microarray analysis to study the overall effects of IAA on the transcriptome of A. brasilense. The transcriptomes of A. brasilense wild-type and the ipdC knockout mutant, both cultured in the absence and presence of exogenously added IAA, were compared.Interfering with the IAA biosynthesis/homeostasis in A. brasilense through inactivation of the ipdC gene or IAA addition results in much broader transcriptional changes than anticipated. Based on the multitude of changes observed by comparing the different transcriptomes, we can conclude that IAA is a signaling molecule in A. brasilense. It appears that the bacterium, when exposed to IAA, adapts itself to the plant rhizosphere, by changing its arsenal of transport proteins and cell surface proteins. A striking example of adaptation to IAA exposure, as happens in the rhizosphere, is the upregulation of a type VI secretion system (T6SS) in the presence of IAA. The T6SS is described as specifically involved in bacterium-eukaryotic host interactions. Additionally, many transcription factors show an altered regulation as well, indicating that the regulatory machinery of the bacterium is changing.

  6. FTIR and Raman spectroscopic studies of selenium nanoparticles synthesised by the bacterium Azospirillum thiophilum

    Science.gov (United States)

    Tugarova, Anna V.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Kamnev, Alexander A.

    2018-03-01

    Vibrational (Fourier transform infrared (FTIR) and Raman) spectroscopic techniques can provide unique molecular-level information on the structural and compositional characteristics of complicated biological objects. Thus, their applications in microbiology and related fields are steadily increasing. In this communication, biogenic selenium nanoparticles (Se NPs) were obtained via selenite (SeO32-) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250 nm; their zeta potential was measured to be minus 18.5 mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500 cm-1 down to 150 cm-1) showed a single very strong band with a maximum at 250 cm-1 which, in line with its increased width (ca. 30 cm-1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs.

  7. Spectroscopic characterization of cell membranes and their constituents of the plant-associated soil bacterium Azospirillum brasilense

    Science.gov (United States)

    Kamnev, A. A.; Antonyuk, L. P.; Matora, L. Yu.; Serebrennikova, O. B.; Sumaroka, M. V.; Colina, M.; Renou-Gonnord, M.-F.; Ignatov, V. V.

    1999-05-01

    Structural and compositional features of bacterial membranes and some of their isolated constituents (cell surface lipopolysaccharide, phospholipids) of the plant-growth-promoting diazotrophic rhizobacterium Azospirillum brasilense (wild-type strain Sp245) were characterized using Fourier transform infrared (FTIR) spectroscopy and some other techniques. FTIR spectra of the cell membranes were shown to comprise the main vibration modes of the relevant lipopolysaccharide and protein components which are believed to be involved in associative plant-bacterium interactions, as well as of phospholipid constituents. The role and functions of metal cations in the structural organization and physicochemical properties of bacterial cell membranes are also discussed considering their accumulation in the membranes from the culture medium.

  8. Fourier transform Raman spectroscopic characterisation of cells of the plant-associated soil bacterium Azospirillum brasilense Sp7

    Science.gov (United States)

    Kamnev, A. A.; Tarantilis, P. A.; Antonyuk, L. P.; Bespalova, L. A.; Polissiou, M. G.; Colina, M.; Gardiner, P. H. E.; Ignatov, V. V.

    2001-05-01

    Structural and compositional features of bacterial cell samples and of lipopolysaccharide-protein complex isolated from the cell surface of the plant-growth-promoting rhizobacterium Azospirillum brasilense (wild-type strain Sp7) were characterised using Fourier transform (FT) Raman spectroscopy. The structural spectroscopic information obtained is analysed and considered together with analytical data on the content of metal cations (Co 2+, Cu 2+ and Zn 2+) in the bacterial cells grown in a standard medium as well as in the presence of each of the cations (0.2 mM). The latter, being taken up by bacterial cells from the culture medium in significant amounts, were shown to induce certain metabolic changes in the bacterium revealed in FT-Raman spectra, which is discussed from the viewpoint of bacterial response to environmental stresses.

  9. Tryptophan, thiamine and indole-3-acetic acid exchange between Chlorella sorokiniana and the plant growth-promoting bacterium Azospirillum brasilense.

    Science.gov (United States)

    Palacios, Oskar A; Gomez-Anduro, Gracia; Bashan, Yoav; de-Bashan, Luz E

    2016-06-01

    During synthetic mutualistic interactions between the microalga Chlorella sorokiniana and the plant growth-promoting bacterium (PGPB) Azospirillum brasilense, mutual exchange of resources involved in producing and releasing the phytohormone indole-3-acetic acid (IAA) by the bacterium, using tryptophan and thiamine released by the microalga, were measured. Although increased activities of tryptophan synthase in C. sorokiniana and indole pyruvate decarboxylase (IPDC) in A. brasilense were observed, we could not detect tryptophan or IAA in the culture medium when both organisms were co-immobilized. This indicates that no extra tryptophan or IAA is produced, apart from the quantities required to sustain the interaction. Over-expression of the ipdC gene occurs at different incubation times: after 48 h, when A. brasilense was immobilized alone and grown in exudates of C. sorokiniana and at 96 h, when A. brasilense was co-immobilized with the microalga. When A. brasilense was cultured in exudates of C. sorokiniana, increased expression of the ipdC gene, corresponding increase in activity of IPDC encoded by the ipdC gene, and increase in IAA production were measured during the first 48 h of incubation. IAA production and release by A. brasilense was found only when tryptophan and thiamine were present in a synthetic growth medium (SGM). The absence of thiamine in SGM yielded no detectable IAA. In summary, this study demonstrates that C. sorokiniana can exude sufficient tryptophan and thiamine to allow IAA production by a PGPB during their interaction. Thiamine is essential for IAA production by A. brasilense and these three metabolites are part of a communication between the two microorganisms. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. (Methyl)ammonium Transport in the Nitrogen-Fixing Bacterium Azospirillum brasilense

    Science.gov (United States)

    Van Dommelen, Anne; Keijers, Veerle; Vanderleyden, Jos; de Zamaroczy, Miklos

    1998-01-01

    An ammonium transporter of Azospirillum brasilense was characterized. In contrast to most previously reported putative prokaryotic NH4+ transporter genes, A. brasilense amtB is not part of an operon with glnB or glnZ which, in A. brasilense, encode nitrogen regulatory proteins PII and PZ, respectively. Sequence analysis predicts the presence of 12 transmembrane domains in the deduced AmtB protein and classifies AmtB as an integral membrane protein. Nitrogen regulates the transcription of the amtB gene in A. brasilense by the Ntr system. amtB is the first gene identified in A. brasilense whose expression is regulated by NtrC. The observation that ammonium uptake is still possible in mutants lacking the AmtB protein suggests the presence of a second NH4+ transport mechanism. Growth of amtB mutants at low ammonium concentrations is reduced compared to that of the wild type. This suggests that AmtB has a role in scavenging ammonium at low concentrations. PMID:9573149

  11. Phenotypical and molecular responses of Arabidopsis thaliana roots as a result of inoculation with the auxin-producing bacterium Azospirillum brasilense.

    Science.gov (United States)

    Spaepen, Stijn; Bossuyt, Stijn; Engelen, Kristof; Marchal, Kathleen; Vanderleyden, Jos

    2014-02-01

    The auxin-producing bacterium Azospirillum brasilense Sp245 can promote the growth of several plant species. The model plant Arabidopsis thaliana was chosen as host plant to gain an insight into the molecular mechanisms that govern this interaction. The determination of differential gene expression in Arabidopsis roots after inoculation with either A. brasilense wild-type or an auxin biosynthesis mutant was achieved by microarray analysis. Arabidopsis thaliana inoculation with A. brasilense wild-type increases the number of lateral roots and root hairs, and elevates the internal auxin concentration in the plant. The A. thaliana root transcriptome undergoes extensive changes on A. brasilense inoculation, and the effects are more pronounced at later time points. The wild-type bacterial strain induces changes in hormone- and defense-related genes, as well as in plant cell wall-related genes. The A. brasilense mutant, however, does not elicit these transcriptional changes to the same extent. There are qualitative and quantitative differences between A. thaliana responses to the wild-type A. brasilense strain and the auxin biosynthesis mutant strain, based on both phenotypic and transcriptomic data. This illustrates the major role played by auxin in the Azospirillum-Arabidopsis interaction, and possibly also in other bacterium-plant interactions. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  12. Increased Growth of the Microalga Chlorella vulgaris when Coimmobilized and Cocultured in Alginate Beads with the Plant-Growth-Promoting Bacterium Azospirillum brasilense†

    Science.gov (United States)

    Gonzalez, Luz E.; Bashan, Yoav

    2000-01-01

    Coimmobilization of the freshwater microalga Chlorella vulgaris and the plant-growth-promoting bacterium Azospirillum brasilense in small alginate beads resulted in a significantly increased growth of the microalga. Dry and fresh weight, total number of cells, size of the microalgal clusters (colonies) within the bead, number of microalgal cells per cluster, and the levels of microalgal pigments significantly increased. Light microscopy revealed that both microorganisms colonized the same cavities inside the beads, though the microalgae tended to concentrate in the more aerated periphery while the bacteria colonized the entire bead. The effect of indole-3-acetic acid addition to microalgal culture prior to immobilization of microorganisms in alginate beads partially imitated the effect of A. brasilense. We propose that coimmobilization of microalgae and plant-growth-promoting bacteria is an effective means of increasing microalgal populations within confined environments. PMID:10742237

  13. Physiological, structural and molecular traits activated in strawberry plants after inoculation with the plant growth-promoting bacterium Azospirillum brasilense REC3.

    Science.gov (United States)

    Guerrero-Molina, M F; Lovaisa, N C; Salazar, S M; Martínez-Zamora, M G; Díaz-Ricci, J C; Pedraza, R O

    2015-05-01

    The plant growth-promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum-colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root-inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post-inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plants. Other early responses activated by REC3 (at 24 hpi) were a decline of lipid peroxidation and up-regulation of strawberry genes involved in defence (FaPR1), bacterial recognition (FaFLS2) and H₂O₂ depuration (FaCAT and FaAPXc). The last may explain the apparent absence of oxidative burst in leaves after bacterial inoculation. Also, REC3 inoculation induced delayed structural responses such as callose deposition and cell wall fortification (at 72 hpi). Results showed that A. brasilense REC3 is capable of exerting beneficial effects on strawberry plants, reinforcing their physiological and cellular characteristics, which in turns contribute to improve plant performance. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. Fourier transform infrared spectroscopic characterisation of heavy metal-induced metabolic changes in the plant-associated soil bacterium Azospirillum brasilense Sp7

    Science.gov (United States)

    Kamnev, A. A.; Antonyuk, L. P.; Tugarova, A. V.; Tarantilis, P. A.; Polissiou, M. G.; Gardiner, P. H. E.

    2002-06-01

    Structural and compositional features of whole cells of the plant-growth-promoting rhizobacterium Azospirillum brasilense Sp7 under standard and heavy metal-stressed conditions are analysed using Fourier transform infrared (FTIR) spectroscopy and compared with the FT-Raman spectroscopic data obtained previously [J. Mol. Struct. 563-564 (2001) 199]. The structural spectroscopic information is considered together with inductively coupled plasma-mass spectrometric (ICP-MS) analytical data on the content of the heavy metal cations (Co2+, Cu2+ and Zn2+) in the bacterial cells. As a bacterial response to heavy metal stress, all the three metals, being taken up by bacterial cells from the culture medium (0.2 mM) in significant amounts (ca. 0.12, 0.48 and 4.2 mg per gram of dry biomass for Co, Cu and Zn, respectively), are shown to induce essential metabolic changes in the bacterium revealed in the spectra, including the accumulation of polyester compounds in bacterial cells and their enhanced hydration affecting certain IR vibrational modes of functional groups involved.

  15. Toxicidade de herbicidas utilizados na cultura da cana-de-açúcar à bactéria diazotrófica Azospirillum brasilense Toxicity of herbicides applied on sugarcane to the diazotrophic bacterium Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    S.O Procópio

    2011-01-01

    Full Text Available Objetivou-se neste trabalho identificar herbicidas utilizados na cultura da cana-de-açúcar que não alteram o crescimento ou a capacidade de fixação biológica de nitrogênio (FBN da bactéria diazotrófica Azospirillum brasi lense. Dezoito herbicidas - paraquat, ametryn, amicarbazone, diuron, metribuzin, [hexazinone + diuron], [hexazinone + clomazone], clomazone, isoxaflutole, sulfentrazone, oxyfluorfen, imazapic, imazapyr, [trifloxysulfuron-sodium + ametryn], S-metolachlor, glyphosate, MSMA e 2,4-D - foram testados em suas doses comerciais quanto ao impacto sobre o crescimento da bactéria em meio líquido DIGs. As variáveis capacidade de suporte de crescimento (carrying capacity do meio de cultura, duração da fase lag e tempo de geração de A. brasilense foram calculadas a partir de dados de densidade ótica obtidos, em intervalos regulares, durante a incubação de culturas por 55 h. O impacto dos herbicidas na atividade da nitrogenase de A. brasilense foi avaliado em meio semissólido NFb, sem N, pela técnica da atividade de redução do acetileno (ARA. Os efeitos dos herbicidas sobre as variáveis de crescimento e ARA foram comparados ao controle pelo teste de Dunnett. Paraquat, oxyfluorfen, [trifloxysulfuron-sodium + ametryn] e glyphosate reduziram a capacidade do meio DIGs em suportar o crescimento de A. brasilense. Esse efeito foi associado ao aumento da duração da fase lag e do tempo de geração para [trifloxysulfuron-sodium + ametryn] e ao aumento no tempo de geração para glyphosate. MSMA, paraquat e amicarbazone reduzem a FBN in vitro de A. brasilense, porém essa redução é mais severa na presença do paraquat. Os demais herbicidas não alteram o crescimento e a FBN de A. brasilense.The objective of this work was to identify the herbicides applied on sugarcane that do not affect the growth nor the process of biological nitrogen fixation (BNF of the diazotrophic bacterium Azospirillum brasilense. Commercial doses of

  16. Azospirillum IV

    International Nuclear Information System (INIS)

    Klingmuller, W.

    1988-01-01

    This book's contents include: Advances in the genetics of Azospirillum brasilense Sp7: Use of Tn5 mutagenesis for gene mapping and identification; Characterization of DNA segments adjacent to the nifHDK genes of Azospirillum brasilense by Sp7 Tn5 site-directed mutagenesis; Selection at the chemostat of Azospirillum brasilense Cd N 2 -fixing at high O 2 pressure. Root hair deformation induced on maize and medicago by an Azospirillum transconjugant containing a Rhizobium meliloti nodulation region. Azospirilla are bacteria that live in association with the roots of many grain crops. Since these bacteria bind molecular nitrogen from the air and excrete plant growth substances, interest has focussed on their potential to increase crop yields

  17. Azospirillum IV

    Energy Technology Data Exchange (ETDEWEB)

    Klingmuller, W.

    1988-01-01

    This book's contents include: Advances in the genetics of Azospirillum brasilense Sp7: Use of Tn5 mutagenesis for gene mapping and identification; Characterization of DNA segments adjacent to the nifHDK genes of Azospirillum brasilense by Sp7 Tn5 site-directed mutagenesis; Selection at the chemostat of Azospirillum brasilense Cd N/sub 2/-fixing at high O/sub 2/ pressure. Root hair deformation induced on maize and medicago by an Azospirillum transconjugant containing a Rhizobium meliloti nodulation region. Azospirilla are bacteria that live in association with the roots of many grain crops. Since these bacteria bind molecular nitrogen from the air and excrete plant growth substances, interest has focussed on their potential to increase crop yields.

  18. Augmenting Iron Accumulation in Cassava by the Beneficial Soil Bacterium Bacillus subtilis (GBO3

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    Monica A Freitas

    2015-08-01

    Full Text Available Cassava (Manihot esculenta, a major staple food in the developing world, provides a basic carbohydrate diet for over half a billion people living in the tropics. Despite the iron abundance in most soils, cassava provides insufficient iron for humans as the edible roots contain 3-12 times less iron than other traditional food crops such as wheat, maize, and rice. With the recent identification that the beneficial soil bacterium Bacillus subtilis (strain GB03 activates iron acquisition machinery to increase metal ion assimilation in Arabidopsis, the question arises as to whether this plant-growth promoting rhizobacterium (PGPR also augments iron assimilation to increase endogenous iron levels in cassava. Biochemical analyses reveal that shoot-propagated cassava with GB03-inoculation exhibit elevated iron accumulation after 140 days of plant growth as determined by X-ray microanalysis and total foliar iron analysis. Growth promotion and increased photosynthetic efficiency were also observed for greenhouse-grown plants with GB03-exposure. These results demonstrate the potential of microbes to increase iron accumulation in an important agricultural crop and is consistent with idea that microbial signaling can regulate plant photosynthesis.

  19. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects.

    Science.gov (United States)

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Milanowski, Janusz

    2016-06-02

    a biocontrol agent permits the decrease of pesticide doses, being a healthy and environmental-friendly procedure. The application of the preparations of this bacterium efficiently protects the stored pome, stone and citrus fruits against invasion of moulds. P. agglomerans strains associated with both rhizosphere and plant tissues (as endophytes) efficiently promote the growth of many plants, including rice and wheat, which are the staple food for the majority of mankind. The promotion mechanisms are diverse and include fixation of atmospheric nitrogen, production of phytohormones, as well as degradation of phytate and phosphate solubilizing which makes the soil phosphorus available for plants. Accordingly, P. agglomerans is regarded as an ideal candidate for an environmental-friendly bioinoculant replacing chemical fertilizers. It has been documented that the Pantoea strains show biodegradation activity on various chemical pollutants of soil and water, including petroleum hydrocarbons and toxic metals. P. agglomerans prevents the penetration of harmful industrial contaminants into deeper parts of soil by biofilm formation, and has an ability to produce hydrogen from waste. Thus, this bacterium appears as a valuable bioremediator which, in some cases, may be acquired as a cheap form of energy. In conclusion, in spite of the proven pathologic role of P. agglomerans in causing occupational diseases of allergic and/or immunotoxic background and accidental infections, the beneficial traits of this species, and of related species of Pantoea genus, are of great value for potential use in many areas of biotechnology. Hence, any restrictions on the use of these organisms and their products should be declined, providing safety precautions at work with the Pantoea biopreparations are maintained.

  20. Pantoea agglomerans : a mysterious bacterium of evil and good. Part IV. Beneficial effects

    Directory of Open Access Journals (Sweden)

    Jacek Dutkiewicz

    2016-06-01

    plant resistance. Its use as a biocontrol agent permits the decrease of pesticide doses, being a healthy and environmental-friendly procedure. The application of the preparations of this bacterium efficiently protects the stored pome, stone and citrus fruits against invasion of moulds. P. agglomerans strains associated with both rhizosphere and plant tissues (as endophytes efficiently promote the growth of many plants, including rice and wheat, which are the staple food for the majority of mankind. The promotion mechanisms are diverse and include fixation of atmospheric nitrogen, production of phytohormones, as well as degradation of phytate and phosphate solubilizing which makes the soil phosphorus available for plants. Accordingly, P. agglomerans is regarded as an ideal candidate for an environmental-friendly bioinoculant replacing chemical fertilizers. It has been documented that the Pantoea strains show biodegradation activity on various chemical pollutants of soil and water, including petroleum hydrocarbons and toxic metals. P. agglomerans prevents the penetration of harmful industrial contaminants into deeper parts of soil by biofilm formation, and has an ability to produce hydrogen from waste. Thus, this bacterium appears as a valuable bioremediator which, in some cases, may be acquired as a cheap form of energy. In conclusion, in spite of the proven pathologic role of P. agglomerans in causing occupational diseases of allergic and/or immunotoxic background and accidental infections, the beneficial traits of this species, and of related species of Pantoea genus, are of great value for potential use in many areas of biotechnology. Hence, any restrictions on the use of these organisms and their products should be declined, providing safety precautions at work with the Pantoea biopreparations are maintained.

  1. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects

    Directory of Open Access Journals (Sweden)

    Jacek Dutkiewicz

    2016-06-01

    production, competition mechanisms or induction of plant resistance. Its use as a biocontrol agent permits the decrease of pesticide doses, being a healthy and environmental-friendly procedure. The application of the preparations of this bacterium efficiently protects the stored pome, stone and citrus fruits against invasion of moulds. [i]P. agglomerans[/i] strains associated with both rhizosphere and plant tissues (as endophytes efficiently promote the growth of many plants, including rice and wheat, which are the staple food for the majority of mankind. The promotion mechanisms are diverse and include fixation of atmospheric nitrogen, production of phytohormones, as well as degradation of phytate and phosphate solubilizing which makes the soil phosphorus available for plants. Accordingly, [i]P. agglomerans[/i] is regarded as an ideal candidate for an environmental-friendly bioinoculant replacing chemical fertilizers. It has been documented that the [i]Pantoea[/i] strains show biodegradation activity on various chemical pollutants of soil and water, including petroleum hydrocarbons and toxic metals. [i]P. agglomerans[/i] prevents the penetration of harmful industrial contaminants into deeper parts of soil by biofilm formation, and has an ability to produce hydrogen from waste. Thus, this bacterium appears as a valuable bioremediator which, in some cases, may be acquired as a cheap form of energy. In conclusion, in spite of the proven pathologic role of [i]P. agglomerans[/i] in causing occupational diseases of allergic and/or immunotoxic background and accidental infections, the beneficial traits of this species, and of related species of [i]Pantoea [/i]genus, are of great value for potential use in many areas of biotechnology. Hence, any restrictions on the use of these organisms and their products should be declined, providing safety precautions at work with the [i]Pantoea[/i] biopreparations are maintained.

  2. Elemental composition of strawberry plants inoculated with the plant growth-promoting bacterium Azospirillum brasilense REC3, assessed with scanning electron microscopy and energy dispersive X-ray analysis.

    Science.gov (United States)

    Guerrero-Molina, M F; Lovaisa, N C; Salazar, S M; Díaz-Ricci, J C; Pedraza, R O

    2014-07-01

    The elemental composition of strawberry plants (Fragaria ananassa cv. Macarena) inoculated with the plant growth-promoting bacterium Azospirillum brasilense REC3, and non-inoculated controls, was studied using scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) analysis. This allowed simultaneous semi-quantification of different elements in a small, solid sample. Plants were inoculated and grown hydroponically in 50% or 100% Hoagland solution, corresponding to limited or optimum nutrient medium, respectively. Bacteria-inoculated plants increased the growth index 45% and 80% compared to controls when grown in 100% and 50% Hoagland solution, respectively. Thus, inoculation with A. brasilense REC3 in a nutrient-limited medium had the strongest effect in terms of increasing both shoot and root biomass and growth index, as already described for Azospirillum inoculated into nutrient-poor soils. SEM-EDS spectra and maps showed the elemental composition and relative distribution of nutrients in strawberry tissues. Leaves contained C, O, N, Na, P, K, Ca and Cu, while roots also had Si and Cl. The organic fraction (C, O and N) accounted for over 96.3% of the total chemical composition; of the mineral fraction, Na had higher accumulation in both leaves and roots. Azospirillum-inoculated and control plants had similar elemental quantities; however, in bacteria-inoculated roots, P was significantly increased (34.33%), which constitutes a major benefit for plant nutrition, while Cu content decreased (35.16%). © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  3. [Insertional mutation in the AZOBR_p60120 gene is accompanied by defects in the synthesis of lipopolysaccharide and calcofluor-binding polysaccharides in the bacterium Azospirillum brasilense Sp245].

    Science.gov (United States)

    Katsy, E I; Prilipov, A G

    2015-03-01

    In the bacterium Azospirillum brasilense Sp245, extracellular calcofluor-binding polysaccharides (Cal+ phenotype) and two types of lipopolysaccharides, LPSI and LPSII, were previously identified. These lipopolysaccharides share the same repeating O-polysaccharide unit but have different antigenic structures and different charges of their O-polysaccharides and/or core oligosaccharides. Several dozens of predicted genes involved in the biosynthesis of polysaccharides have been localized in the AZOBR_p6 plasmid of strain Sp245 (GenBank accession no. HE577333). In the present work, it was demonstrated that an artificial transposon Omegon-Km had inserted into the central region of the AZOBR_p60120 gene in the A. brasilense Sp245 LPSI- Cal- KM252 mutant. In A. brasilense strain Sp245, this plasmid gene encodes a putative glycosyltransferase containing conserved domains characteristic of the enzymes participating in the synthesis of O-polysaccharides and capsular polysaccharides (accession no. YP004987664). In mutant KM252, a respective predicted protein is expected to be completely inactivated. As a result of the analysis of the EcoRI fragment of the AZOBR_p6 plasmid, encompassing the AZOBR_p60120 gene and a number of other loci, novel data on the structure of AZOBR_p6 were obtained: an approximately 5-kb gap (GenBank accession no. KM189439) was closed in the nucleotide sequence of this plasmid.

  4. Soil components mitigate the antimicrobial effects of silver nanoparticles towards a beneficial soil bacterium, Pseudomonas chlororaphis O6

    Energy Technology Data Exchange (ETDEWEB)

    Calder, Alyssa J. [Department of Biological Engineering, Utah State University, Logan, UT 84322 (United States); Dimkpa, Christian O. [Department of Biological Engineering, Utah State University, Logan, UT 84322 (United States); Department of Biology, Utah State University, Logan, UT 84322 (United States); McLean, Joan E. [Utah Water Research Laboratory, Utah State University, Logan, UT 84322 (United States); Britt, David W. [Department of Biological Engineering, Utah State University, Logan, UT 84322 (United States); Johnson, William [Geology and Geophysics, University of Utah, Salt Lake City, UT 84112 (United States); Anderson, Anne J., E-mail: anne.anderson@usu.edu [Department of Biology, Utah State University, Logan, UT 84322 (United States)

    2012-07-01

    Silver nanoparticles (Ag NPs) are widely used for their antimicrobial activity and consequently the particles will become environmental contaminants. This study evaluated in sand and soil matrices the toxicity of 10 nm spherical Ag NPs (1 and 3 mg Ag/L) toward a beneficial soil bacterium, Pseudomonas chlororaphis O6. In sand, both NP doses resulted in loss in bacterial culturability whereas in a loam soil, no cell death was observed. Amendments of sand with clays (30% v/v kaolinite or bentonite) did not protect the bacterium when challenged with Ag NPs. However, culturability of the bacterium was maintained when the Ag NP-amended sand was mixed with soil pore water or humic acid. Imaging by atomic force microscopy revealed aggregation of single nanoparticles in water, and their embedding into background material when suspended in pore water and humic acids. Zeta potential measurements supported aggregation and surface charge modifications with pore water and humic acids. Measurement of soluble Ag in the microcosms and geochemical modeling to deduce the free ion concentration revealed bacterial culturability was governed by the predicted free Ag ion concentrations. Our study confirmed the importance of Ag NPs as a source of ions and illustrated that processes accounting for protection in soil against Ag NPs involved distinct NP- and ion-effects. Processes affecting NP bioactivity involved surface charge changes due to sorption of Ca{sup 2+} from the pore water leading to agglomeration and coating of the NPs with humic acid and other organic materials. Removal of bioactive ions included the formation of soluble Ag complexes with dissolved organic carbon and precipitation of Ag ions with chloride in pore water. We conclude that mitigation of toxicity of Ag NPs in soils towards a soil bacterium resides in several interactions that differentially involve protection from the Ag NPs or the ions they produce. - Highlights: Black-Right-Pointing-Pointer Silver nanoparticles

  5. Soil components mitigate the antimicrobial effects of silver nanoparticles towards a beneficial soil bacterium, Pseudomonas chlororaphis O6

    International Nuclear Information System (INIS)

    Calder, Alyssa J.; Dimkpa, Christian O.; McLean, Joan E.; Britt, David W.; Johnson, William; Anderson, Anne J.

    2012-01-01

    Silver nanoparticles (Ag NPs) are widely used for their antimicrobial activity and consequently the particles will become environmental contaminants. This study evaluated in sand and soil matrices the toxicity of 10 nm spherical Ag NPs (1 and 3 mg Ag/L) toward a beneficial soil bacterium, Pseudomonas chlororaphis O6. In sand, both NP doses resulted in loss in bacterial culturability whereas in a loam soil, no cell death was observed. Amendments of sand with clays (30% v/v kaolinite or bentonite) did not protect the bacterium when challenged with Ag NPs. However, culturability of the bacterium was maintained when the Ag NP-amended sand was mixed with soil pore water or humic acid. Imaging by atomic force microscopy revealed aggregation of single nanoparticles in water, and their embedding into background material when suspended in pore water and humic acids. Zeta potential measurements supported aggregation and surface charge modifications with pore water and humic acids. Measurement of soluble Ag in the microcosms and geochemical modeling to deduce the free ion concentration revealed bacterial culturability was governed by the predicted free Ag ion concentrations. Our study confirmed the importance of Ag NPs as a source of ions and illustrated that processes accounting for protection in soil against Ag NPs involved distinct NP- and ion-effects. Processes affecting NP bioactivity involved surface charge changes due to sorption of Ca 2+ from the pore water leading to agglomeration and coating of the NPs with humic acid and other organic materials. Removal of bioactive ions included the formation of soluble Ag complexes with dissolved organic carbon and precipitation of Ag ions with chloride in pore water. We conclude that mitigation of toxicity of Ag NPs in soils towards a soil bacterium resides in several interactions that differentially involve protection from the Ag NPs or the ions they produce. - Highlights: ► Silver nanoparticles (Ag NPs) are widely used for

  6. [Mutants of bacterium Azospirillum brasilense Sp245 with Omegon insertion in mmsB or fabG genes of lipid metabolism are defective in motility and flagellation].

    Science.gov (United States)

    Kovtunov, E A; Shelud'ko, A V; Chernyshova, M P; Petrova, L P; Katsy, E I

    2013-11-01

    Bacteria Azospirillum brasilense have mixed flagellation: in addition to the polar flagellum, numerous lateral flagella are formed in their cells on medium with increased density. Flagella determine the active swimming and swarming capacities of azospirilla. Using A. brasilense Sp245 as an example, we showed that the Omegon-Km artificial transposon insertion into the chromosomal gene for 3-hydroxyisobutyrate dehydrogenase (mmsB) was concurrent with the appearance of significant defects in the formation of polar flagella and with the paralysis of lateral flagella. The Sp245 mutant with the Omegon insertion into the plasmid AZOBR_p1-borne gene for 3-oxoacyl-[acyl-carrier protein]-reductase (fabG) showed the complete loss of flagella and the swarming capacity, as well as significant defects in polar flagellar assembly (though some cells are still motile in liquid medium). The viability of the A. brasilense Sp245 mutants with the Omegon insertion into the mmsB or fabG gene was not reduced. No considerable differences in the fatty acid composition of whole cell lipid extracts were found for the A. brasilense Sp245 strain and its mmsB and fabG mutants.

  7. Role of ethylene and related gene expression in the interaction between strawberry plants and the plant growth-promoting bacterium Azospirillum brasilense.

    Science.gov (United States)

    Elías, J M; Guerrero-Molina, M F; Martínez-Zamora, M G; Díaz-Ricci, J C; Pedraza, R O

    2018-05-01

    Induced systemic resistance (ISR) is one of the indirect mechanisms of growth promotion exerted by plant growth-promoting bacteria, and can be mediated by ethylene (ET). We assessed ET production and the expression of related genes in the Azospirillum-strawberry plant interaction. Ethylene production was evaluated by gas chromatography in plants inoculated or not with A. brasilense REC3. Also, plants were treated with AgNO 3 , an inhibitor of ET biosynthesis; with 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor of ET biosynthesis; and with indole acetic acid (IAA). Plant dry biomass and the growth index were determined to assess the growth-promoting effect of A. brasilense REC3 in strawberry plants. Quantitative real time PCR (qRT-PCR) was performed to analyse relative expression of the genes Faetr1, Faers1 and Faein4, which encode ET receptors; Factr1 and Faein2, involved in the ET signalling pathway; Faacs1 encoding ACC synthase; Faaco1 encoding ACC oxidase; and Faaux1 and Faami1 for IAA synthesis enzymes. Results showed that ET acts as a rapid and transient signal in the first 12 h post-treatment. A. brasilense REC3-inoculated plants had a significantly higher growth index compared to control plants. Modulation of the genes Faetr1, Faers1, Faein4, Factr1, Faein2 and Faaco1 indicated activation of ET synthesis and signalling pathways. The up-regulation of Faaux1 and Faami1 involved in IAA synthesis suggested that inoculation with A. brasilense REC3 induces production of this auxin, modulating ET signalling. Ethylene production and up-regulation of genes associated with ET signalling in strawberry plants inoculated with A. brasilense REC3 support the priming activation characteristic of ISR. This type of resistance and the activation of systemic acquired resistance previously observed in this interaction indicate that both are present in strawberry plants, could act synergistically and increase protection against pathogens. © 2018 German Society

  8. SEED INOCULATION WITH Azospirillum brasilense, ASSOCIATED WITH THE USE OF BIOREGULATORS IN MAIZE

    Directory of Open Access Journals (Sweden)

    ALESSANDRO DE LUCCA E BRACCINI

    2012-01-01

    Full Text Available The inoculation of seeds with the bacterium Azospirillum has been carried out in maize culture and other grasses. The application of growth bio-regulators is another technology whose results in maize culture have yet to become more widespread. Current study evaluates the agronomic effectiveness of seed inoculation with Azospirillum brasilense in maize, associated with the use of the growth regulator Stimulate ®. Triple hybrid maize CD 304 underwent the following treatments: 1 - control without nitrogen and without Azospirillum brasilense; 2 - Treatment without nitrogen but with Azospirillum brasilense; 3 - Treatment without nitrogen but with Azospirillum brasilense + Stimulate ®; 4 - Treatment with 50% of nitrogen dose recommended for maize culture; 5 - Treatment with 50% of nitrogen dose and inoculation with Azospirillum brasilense; 6 - Same as 5 but with Stimulate ®; 7 - Total N recommended; 8 - Total N recommended + Azospirillum brasilense ; 9 - Total N recommended + Azospirillum brasilense + Stimulate ®. The inoculation of maize seeds with Azospirillum brasilense increases plant height and grain yield when compared with rates in control. The use of 50% of N dose in sowing, associated with the inoculation of maize seeds with Azospirillum brasilense at 200 mL ha-1 (mixed to the seeds and associated with Stimulate ® (in foliar application, is viable.

  9. Transcriptional patterns in both host and bacterium underlie a daily rhythm of anatomical and metabolic change in a beneficial symbiosis.

    Science.gov (United States)

    Wier, Andrew M; Nyholm, Spencer V; Mandel, Mark J; Massengo-Tiassé, R Prisca; Schaefer, Amy L; Koroleva, Irina; Splinter-Bondurant, Sandra; Brown, Bartley; Manzella, Liliana; Snir, Einat; Almabrazi, Hakeem; Scheetz, Todd E; Bonaldo, Maria de Fatima; Casavant, Thomas L; Soares, M Bento; Cronan, John E; Reed, Jennifer L; Ruby, Edward G; McFall-Ngai, Margaret J

    2010-02-02

    Mechanisms for controlling symbiont populations are critical for maintaining the associations that exist between a host and its microbial partners. We describe here the transcriptional, metabolic, and ultrastructural characteristics of a diel rhythm that occurs in the symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri. The rhythm is driven by the host's expulsion from its light-emitting organ of most of the symbiont population each day at dawn. The transcriptomes of both the host epithelium that supports the symbionts and the symbiont population itself were characterized and compared at four times over this daily cycle. The greatest fluctuation in gene expression of both partners occurred as the day began. Most notable was an up-regulation in the host of >50 cytoskeleton-related genes just before dawn and their subsequent down-regulation within 6 h. Examination of the epithelium by TEM revealed a corresponding restructuring, characterized by effacement and blebbing of its apical surface. After the dawn expulsion, the epithelium reestablished its polarity, and the residual symbionts began growing, repopulating the light organ. Analysis of the symbiont transcriptome suggested that the bacteria respond to the effacement by up-regulating genes associated with anaerobic respiration of glycerol; supporting this finding, lipid analysis of the symbionts' membranes indicated a direct incorporation of host-derived fatty acids. After 12 h, the metabolic signature of the symbiont population shifted to one characteristic of chitin fermentation, which continued until the following dawn. Thus, the persistent maintenance of the squid-vibrio symbiosis is tied to a dynamic diel rhythm that involves both partners.

  10. Mitigation of salt stress in white clover (Trifolium repens) by Azospirillum brasilense and its inoculation effect.

    Science.gov (United States)

    Khalid, Muhammad; Bilal, Muhammad; Hassani, Danial; Iqbal, Hafiz M N; Wang, Hang; Huang, Danfeng

    2017-12-01

    Salinity is one of the increasingly serious environmental problems worldwide for cultivating agricultural crops. The present study was aimed to ascertain the potential of beneficial soil bacterium Azospirillum brasilense to alleviate saline stress in Trifolium repens. Experimental plants (white clover) were grown from seeds and inoculated with or without A. brasilense bacterial strain supplemented with 0, 40, 80, or 120 mM NaCl into soil. The growth attributes including, shoot heights, root lengths, fresh and dry weights, leaf area and chlorophyll content were significantly enhanced in T. repens plants grown in A. brasilense inoculated soil than un-inoculated controls, particularly under elevated salinity conditions (40, 80 and 120 mM NaCl). Malondialdehyde content of leaf was recorded to be declined under saline conditions. Moreover, the K + /Na + ratio was also improved in bacterium-inoculated plants, since A. brasilense significantly reduced the root and shoot Na + level under high salty environment. Results revealed that soil inoculation with A. brasilense could significantly promote T. repens growth under both non-saline and saline environments, and this study might be extended to other vegetables and crops for the germination and growth enhancement.

  11. Azospirillum brasilense and Azospirillum lipoferum Hydrolyze Conjugates of GA20 and Metabolize the Resultant Aglycones to GA1 in Seedlings of Rice Dwarf Mutants1

    Science.gov (United States)

    Cassán, Fabricio; Bottini, Rubén; Schneider, Gernot; Piccoli, Patricia

    2001-01-01

    Azospirillum species are plant growth-promotive bacteria whose beneficial effects have been postulated to be partially due to production of phytohormones, including gibberellins (GAs). In this work, Azospirillum brasilense strain Cd and Azospirillum lipoferum strain USA 5b promoted sheath elongation growth of two single gene GA-deficient dwarf rice (Oryza sativa) mutants, dy and dx, when the inoculated seedlings were supplied with [17,17-2H2]GA20-glucosyl ester or [17,17- 2H2]GA20-glucosyl ether. Results of capillary gas chromatography-mass spectrometry analysis show that this growth was due primarily to release of the aglycone [17,17-2H2]GA20 and its subsequent 3β-hydroxylation to [17,17-2H2]GA1 by the microorganism for the dy mutant, and by both the rice plant and microorganism for the dx mutant. PMID:11299384

  12. Effect of Azospirillum brasilense inoculation on urease activity in soil and gamma-sterilized soil

    International Nuclear Information System (INIS)

    Perotti, E.B.R.; Pidello, A.

    1999-01-01

    Azospirillum spp. is considered a PGPR (plant growth promoting rhyzobacteria) bacterium, besides this interest, there is little information about its effects on other functional microbial groups or on soil enzymes. In this paper, the impact that Azospirillum brasilense 7001 inoculation has on urease activity expression in a Typic Argiudoll was studied. Evolution of urease activity of soil and of gamma irradiation (25 KGy) sterilized soil, and the inoculated strain survival were tested. The relation between soil urease activity and soil NH 4 +-N was also determined. In γ-sterilized soil, urease activity of inoculated soil increased with time, showing significant differences with regard to the control soil without inoculum at day 15. In non-sterile soil, urease activity decreased during the studied period in all treatments; in inoculated soil, it showed higher or lower values than the control depending on sampling time. Azospirillum survival was important and different according to soil condition conditions. The negative relation between NH 4 +-N concentration and soil urease activity (r 2 = 0.62) was observed in inoculated soil. The role of the addition of autoclaved inoculum in the urease activity expression is discussed. The research proves that in both studied situations Azospirillum modified soil urease activity, and that the competition with native microorganisms and soil NH 4 +-N may affect this bacterium capacity. (author)

  13. Evaluation of reference genes for gene expression analysis using quantitative RT-PCR in Azospirillum brasilense.

    Science.gov (United States)

    McMillan, Mary; Pereg, Lily

    2014-01-01

    Azospirillum brasilense is a nitrogen fixing bacterium that has been shown to have various beneficial effects on plant growth and yield. Under normal conditions A. brasilense exists in a motile flagellated form, which, under starvation or stress conditions, can undergo differentiation into an encapsulated, cyst-like form. Quantitative RT-PCR can be used to analyse changes in gene expression during this differentiation process. The accuracy of quantification of mRNA levels by qRT-PCR relies on the normalisation of data against stably expressed reference genes. No suitable set of reference genes has yet been described for A. brasilense. Here we evaluated the expression of ten candidate reference genes (16S rRNA, gapB, glyA, gyrA, proC, pykA, recA, recF, rpoD, and tpiA) in wild-type and mutant A. brasilense strains under different culture conditions, including conditions that induce differentiation. Analysis with the software programs BestKeeper, NormFinder and GeNorm indicated that gyrA, glyA and recA are the most stably expressed reference genes in A. brasilense. The results also suggested that the use of two reference genes (gyrA and glyA) is sufficient for effective normalisation of qRT-PCR data.

  14. Evaluation of reference genes for gene expression analysis using quantitative RT-PCR in Azospirillum brasilense.

    Directory of Open Access Journals (Sweden)

    Mary McMillan

    Full Text Available Azospirillum brasilense is a nitrogen fixing bacterium that has been shown to have various beneficial effects on plant growth and yield. Under normal conditions A. brasilense exists in a motile flagellated form, which, under starvation or stress conditions, can undergo differentiation into an encapsulated, cyst-like form. Quantitative RT-PCR can be used to analyse changes in gene expression during this differentiation process. The accuracy of quantification of mRNA levels by qRT-PCR relies on the normalisation of data against stably expressed reference genes. No suitable set of reference genes has yet been described for A. brasilense. Here we evaluated the expression of ten candidate reference genes (16S rRNA, gapB, glyA, gyrA, proC, pykA, recA, recF, rpoD, and tpiA in wild-type and mutant A. brasilense strains under different culture conditions, including conditions that induce differentiation. Analysis with the software programs BestKeeper, NormFinder and GeNorm indicated that gyrA, glyA and recA are the most stably expressed reference genes in A. brasilense. The results also suggested that the use of two reference genes (gyrA and glyA is sufficient for effective normalisation of qRT-PCR data.

  15. Economic analysis of corn inoculated with Azospirillum brasilense associated with nitrogen sources and doses

    Directory of Open Access Journals (Sweden)

    Fernando Shintate Galindo

    2017-08-01

    Full Text Available Azospirillum brasilense is a bacterium known for its biological nitrogen fixation (BNF in corn crops. However, there is a lack of comprehensive research defining how much mineral N should be applied to maximize the efficiency of BNF and attain high, economically sustainable yields. Moreover, it would be interesting to investigate whether adding urea with NBPT urease inhibitor might increase BNF in grasses. Therefore, the aim of this study was to determine the effect of inoculation with Azospirillum brasilense associated with N sources and doses in a Cerrado biome soil by evaluating the grain yield of irrigated corn in economic terms. The experiment was conducted in Selvíria, MS, Brazil under a no-till system on a Latossolo Vermelho distrófico (Oxisol. The experiment was set up as a randomized block design with four replications in a 2 × 5 × 2 factorial arrangement consisting of two sources of N (urea and urea with NBPT urease enzyme inhibitor and five N doses applied as top-dressing (0, 50, 100, 150, and 200 kg ha-1, with and without the inoculation of seeds with A. brasilense. Inoculation with Azospirillum brasilense makes corn growth much more profitable, irrespective of the dose and source of N. Addition of 200 kg ha-1 N in the form of conventional urea coupled with inoculation with Azospirillum brasilense increases grain yield; however, the highest economic return is obtained with N applied at 100 kg ha-1 with conventional urea and inoculation.

  16. STUDY OF AZOSPIRILLUM LECTINS INFLUENCE ON HYDROGEN PEROXIDE PRODUCTION IN WHEAT-ROOTS

    Directory of Open Access Journals (Sweden)

    Alen’kina S.A.

    2009-12-01

    Full Text Available It was found that two cell-surface lectins isolated from the nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 and from its mutant defective in lectin activity, A. brasilense Sp7.2.3 can stimulate rapid formation of hydrogen peroxide, associated with an increase in the activities of oxalate oxidase and peroxidase in the roots of wheat seedlings. The most advantageous and most rapidly induced pathway of hydrogen peroxide formation was the oxidation of oxalic acid by oxalate oxidase because in this case, a 10-min treatment of the roots with the lectins at 10 µg ml-1 was sufficient. The data from this study attest that the Azospirillum lectins can act as inducers of adaptation processes in the roots of wheat seedlings.

  17. Mutational analysis of GlnB residues critical for NifA activation in Azospirillum brasilense.

    Science.gov (United States)

    Inaba, Juliana; Thornton, Jeremy; Huergo, Luciano Fernandes; Monteiro, Rose Adele; Klassen, Giseli; Pedrosa, Fábio de Oliveira; Merrick, Mike; de Souza, Emanuel Maltempi

    2015-02-01

    PII proteins are signal transduction that sense cellular nitrogen status and relay this signals to other targets. Azospirillum brasilense is a nitrogen fixing bacterium, which associates with grasses and cereals promoting beneficial effects on plant growth and crop yields. A. brasilense contains two PII encoding genes, named glnB and glnZ. In this paper, glnB was mutagenised in order to identify amino acid residues involved in GlnB signaling. Two variants were obtained by random mutagenesis, GlnBL13P and GlnBV100A and a site directed mutant, GlnBY51F, was obtained. Their ability to complement nitrogenase activity of glnB mutant strains of A. brasilense were determined. The variant proteins were also overexpressed in Escherichia coli, purified and characterized biochemically. None of the GlnB variant forms was able to restore nitrogenase activity in glnB mutant strains of A. brasilense LFH3 and 7628. The purified GlnBY51F and GlnBL13P proteins could not be uridylylated by GlnD, whereas GlnBV100A was uridylylated but at only 20% of the rate for wild type GlnB. Biochemical and computational analyses suggest that residue Leu13, located in the α helix 1 of GlnB, is important to maintain GlnB trimeric structure and function. The substitution V100A led to a lower affinity for ATP binding. Together the results suggest that NifA activation requires uridylylated GlnB bound to ATP. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Azospirillum brasilense ameliorates the response of Arabidopsis thaliana to drought mainly via enhancement of ABA levels.

    Science.gov (United States)

    Cohen, Ana C; Bottini, Rubén; Pontin, Mariela; Berli, Federico J; Moreno, Daniela; Boccanlandro, Hernán; Travaglia, Claudia N; Piccoli, Patricia N

    2015-01-01

    Production of phytohormones is one of the main mechanisms to explain the beneficial effects of plant growth-promoting rhizobacteria (PGPR) such as Azospirillum sp. The PGPRs induce plant growth and development, and reduce stress susceptibility. However, little is known regarding the stress-related phytohormone abscisic acid (ABA) produced by bacteria. We investigated the effects of Azospirillum brasilense Sp 245 strain on Arabidopsis thaliana Col-0 and aba2-1 mutant plants, evaluating the morphophysiological and biochemical responses when watered and in drought. We used an in vitro-grown system to study changes in the root volume and architecture after inoculation with Azospirillum in Arabidopsis wild-type Col-0 and on the mutant aba2-1, during early growth. To examine Arabidopsis development and reproductive success as affected by the bacteria, ABA and drought, a pot experiment using Arabidopsis Col-0 plants was also carried out. Azospirillum brasilense augmented plant biomass, altered root architecture by increasing lateral roots number, stimulated photosynthetic and photoprotective pigments and retarded water loss in correlation with incremented ABA levels. As well, inoculation improved plants seed yield, plants survival, proline levels and relative leaf water content; it also decreased stomatal conductance, malondialdehyde and relative soil water content in plants submitted to drought. Arabidopsis inoculation with A. brasilense improved plants performance, especially in drought. © 2014 Scandinavian Plant Physiology Society.

  19. Increased acidification in the rhizosphere of cactus seedlings induced by Azospirillum brasilense

    Science.gov (United States)

    Carrillo, Angel; Li, Ching; Bashan, Yoav

    2002-08-01

    Acidification of the rhizosphere of cactus seedlings (giant cardon, Pachycereus pringlei) after inoculation with the plant growth-promoting bacterium Azospirillum brasilense Cd, in the presence or absence of ammonium and nitrate, was studied to understand how to increase growth of cardon seedlings in poor desert soils. While ammonium enhanced rhizosphere and liquid culture acidification, inoculation with the bacteria enhanced it further. On the other hand, nitrate increased pH of the rhizosphere, but combined with the bacterial inoculation, increase in pH was significantly smaller. Bacterial inoculation with ammonium enhanced plant growth.

  20. Hydrogen oxidation in Azospirillum brasilense

    Energy Technology Data Exchange (ETDEWEB)

    Tibelius, K.

    1984-01-01

    Hydrogen oxidation by Azospirillum brasilense Sp7 was studied in N/sub 2/-fixing and NH/sub 4//sup +/-grown batch cultures. The K/sub m/ for H/sub 2/ of O/sub 2/-dependent H/sup 3/H oxidation in whole cells was 9 uM. The rates of H/sup 3/H and H/sub 2/ oxidation were very similar, indicating that the initial H/sub 2/ activation step in the overall H/sub 2/ oxidation reaction was not rate-limiting and that H/sup 3/H oxidation was a valid measure of H/sub 2/-oxidation activity. Hydrogen-oxidation activity was inhibited irreversibly by air. In N-free cultures the O/sub 2/ optima for O/sub 2/-dependent H/sub 2/ oxidation, ranging from 0.5-1.25% O/sub 2/ depending on the phase of growth, were significantly higher than those of C/sub 2/H/sub 2/ reduction, 0.15-0.35%, suggesting that the H/sub 2/-oxidation system may have a limited ability to aid in the protection of nitrogenase against inactivation by O/sub 2/. Oxygen-dependent H/sub 2/ oxidation was inhibited by NO/sub 2//sup +/, NO, CO, and C/sub 2/H/sub 2/ with apparent K/sub 1/ values of 20, 0.4, 28, and 88 uM, respectively. Hydrogen-oxidation activity was 50 to 100 times higher in denitrifying cultures when the terminal electron acceptor for growth was N/sub 2/O rather than NO/sub 3//sup -/, possibly due to the irreversible inhibition of hydrogenase by NO/sub 2//sup -/ and NO in NO/sub 3//sup -/-grown cultures.

  1. Intercropping Urochloa brizantha and sorghum inoculated with Azospirillum brasilense for silage

    Directory of Open Access Journals (Sweden)

    Allan Hisashi Nakao

    Full Text Available ABSTRACT Livestock performance in the Brazilian Cerrado has been limited by the low availability of good quality fodder, especially during periods of low rainfall. The aim of this study was to evaluate growth and dry matter production in two cultivars of sorghum, inoculated or not with diazotrophic bacteria, and as a monocrop or intercropped with palisade grass under a system of crop-livestock integration. The experiments were carried out in the field in the Cerrado region during the autumn-winter period of 2015 and 2016, on the experimental farm of the Faculty of Engineering at Ilha Solteira, UNESP, in Selvíria, in the State of Mato Groso do Sul, Brazil (MS. A randomised complete block experimental design was used in a 2 x 2 x 2 factorial scheme with four replications. The treatments corresponded to two agricultural years (2015 and 2016; the cultivation of dual-purpose grain sorghum, alone or intercropped with palisade grass; with or without inoculation of the sorghum seeds with the bacterium Azospirillum brasilense. The dry matter production of the plant components and plant growth were evaluated for the preparation of silage. Inoculation of sorghum seeds with the bacterium Azospirillum brasilense increases the production of plant dry matter for silage, irrespective of the cultivar or intercrop. Dual-purpose grain sorghum intercropped with palisade grass is a viable agronomic system for producing plant matter for silage during the autumn season.

  2. Network Analysis of Plasmidomes: The Azospirillum brasilense Sp245 Case

    Science.gov (United States)

    Fondi, Marco

    2014-01-01

    Azospirillum brasilense is a nitrogen-fixing bacterium living in association with plant roots. The genome of the strain Sp245, isolated in Brazil from wheat roots, consists of one chromosome and six plasmids. In this work, the A. brasilense Sp245 plasmids were analyzed in order to shed some light on the evolutionary pathways they followed over time. To this purpose, a similarity network approach was applied in order to identify the evolutionary relationships among all the A. brasilense plasmids encoded proteins; in this context a computational pipeline specifically devoted to the analysis and the visualization of the network-like evolutionary relationships among different plasmids molecules was developed. This information was supplemented with a detailed (in silico) functional characterization of both the connected (i.e., sharing homology with other sequences in the dataset) and the unconnected (i.e., not sharing homology) components of the network. Furthermore, the most likely source organism for each of the genes encoded by A. brasilense plasmids was checked, allowing the identification of possible trends of gene loss/gain in this microorganism. Data obtained provided a detailed description of the evolutionary landscape of the plasmids of A. brasilense Sp245, suggesting some of the molecular mechanisms responsible for the present-day structure of these molecules. PMID:25610702

  3. Azospirillum spp. from native forage grasses in Brazilian Pantanal floodplain: biodiversity and plant growth promotion potential.

    Science.gov (United States)

    Souza, Mayara S T; de Baura, Valter A; Santos, Sandra A; Fernandes-Júnior, Paulo Ivan; Reis Junior, Fábio B; Marques, Maria Rita; Paggi, Gecele Matos; da Silva Brasil, Marivaine

    2017-04-01

    A sustainable alternative to improve yield and the nutritive value of forage is the use of plant growth-promoting bacteria (PGPB) that release nutrients, synthesize plant hormones and protect against phytopathogens (among other mechanisms). Azospirillum genus is considered an important PGPB, due to the beneficial effects observed when inoculated in several plants. The aim of this study was to evaluate the diversity of new Azospirillum isolates and select bacteria according to the plant growth promotion ability in three forage species from the Brazilian Pantanal floodplain: Axonopus purpusii, Hymenachne amplexicaulis and Mesosetum chaseae. The identification of bacterial isolates was performed using specific primers for Azospirillum in PCR reactions and partial sequencing of the 16S rRNA and nifH genes. The isolates were evaluated in vitro considering biological nitrogen fixation (BNF) and indole-3-acetic acid (IAA) production. Based on the results of BNF and IAA, selected isolates and two reference strains were tested by inoculation. At 31 days after planting the plant height, shoot dry matter, shoot protein content and root volume were evaluated. All isolates were able to fix nitrogen and produce IAA, with values ranging from 25.86 to 51.26 mg N mL -1 and 107-1038 µmol L -1 , respectively. The inoculation of H. amplexicaulis and A. purpusii increased root volume and shoot dry matter. There were positive effects of Azospirillum inoculation on Mesosetum chaseae regarding plant height, shoot dry matter and root volume. Isolates MAY1, MAY3 and MAY12 were considered promising for subsequent inoculation studies in field conditions.

  4. 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

  5. Co2 + interaction with Azospirillum brasilense Sp7 cells: a 57Co emission Mössbauer spectroscopic study

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Biró, Borbála; Kovács, Krisztina; Homonnay, Zoltán; Kuzmann, Ernő; Vértes, Attila

    2012-03-01

    Preliminary 57Co emission Mössbauer spectroscopic data were obtained for the soil bacterium Azospirillum brasilense Sp7 ( T = 80 K) in frozen 57Co2 + -containing suspensions and in their dried residues. The Mössbauer parameters were compared with those for A. brasilense strain Sp245 differing from strain Sp7 by ecological behaviour. Live cells of both strains showed metabolic transformations of 57Co2 + within an hour. Differences in the parameters observed for the two strains under similar conditions suggest dissimilarities in their metabolic response to Co2 + .

  6. Co{sup 2 + } interaction with Azospirillum brasilense Sp7 cells: a {sup 57}Co emission Moessbauer spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, Alexander A.; Tugarova, Anna V. [Russian Academy of Sciences, Institute of Biochemistry and Physiology of Plants and Microorganisms (Russian Federation); Biro, Borbala [Hungarian Academy of Sciences, Research Institute for Soil Science and Agricultural Chemistry (Hungary); Kovacs, Krisztina, E-mail: kkriszti@chem.elte.hu; Homonnay, Zoltan; Kuzmann, Erno; Vertes, Attila [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

    2012-03-15

    Preliminary {sup 57}Co emission Moessbauer spectroscopic data were obtained for the soil bacterium Azospirillum brasilense Sp7 (T = 80 K) in frozen {sup 57}Co{sup 2 + }-containing suspensions and in their dried residues. The Moessbauer parameters were compared with those for A. brasilense strain Sp245 differing from strain Sp7 by ecological behaviour. Live cells of both strains showed metabolic transformations of {sup 57}Co{sup 2 + } within an hour. Differences in the parameters observed for the two strains under similar conditions suggest dissimilarities in their metabolic response to Co{sup 2 + }.

  7. Doses and application methods of Azospirillum brasilense in irrigated upland rice

    Directory of Open Access Journals (Sweden)

    Nayara F. S. Garcia

    Full Text Available ABSTRACT The study was carried out in Selvíria-MS, in the 2011/12 and 2012/13 agricultural years, aiming to evaluate the efficiency of Azospirillum brasilense in nitrogen fixation in upland rice, as a function of doses and application methods of the inoculant containing this diazotrophic bacterium. The experimental design was randomized blocks, arranged in a 4 x 4 factorial scheme, with 4 doses of inoculant (control without inoculation, 100, 200 and 300 mL of the commercial product ha-1 and 4 application methods (seed inoculation, application in the sowing furrow, soil spraying after sowing, and foliar spraying at the beginning of plant tillering, with 4 replicates. During the experiment, the agronomic characteristics, production components and yield of the rice crop were evaluated. It was concluded that the inoculant containing Azospirillum brasilense promotes increase (19% in the yield of upland rice under sprinkler irrigation when used at the dose of 200 mL ha-1, regardless of the application methods.

  8. Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense.

    Science.gov (United States)

    Fibach-Paldi, Sharon; Burdman, Saul; Okon, Yaacov

    2012-01-01

    Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utilization of polybetahydroxyalkanoate polymers are important for the shelf life of the bacteria in production of inoculants, products containing bacterial cells in a suitable carrier for agricultural use. Azospirillum brasilense is able to fix nitrogen, but despite some controversy, as judging from most systems evaluated so far, contribution of fixed nitrogen by this bacterium does not seem to play a major role in plant growth promotion. In this review, we focus on recent advances in the understanding of physiological properties of A. brasilense that are important for rhizosphere performance and successful interactions with plant roots. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  9. [Biosynthesis of gold nanoparticles by Azospirillum brasilense].

    Science.gov (United States)

    Kupriashina, M A; Vetchinkina, E P; Burov, A M; Ponomareva, E G; Nikitina, V E

    2014-01-01

    Plant-associated nitrogen-fixing soil bacteria Azospirillum brasilense were shown to reduce the gold of chloroauric acid to elemental gold, resulting in formation of gold nanoparicles. Extracellular phenoloxidizing enzymes (laccases and Mn peroxidases) were shown to participate in reduction of Au+3 (HAuCl4) to Au(0). Transmission electron microscopy revealed accumulation of colloidal gold nanoparticles of diverse shape in the culture liquid of A. brasilense strains Sp245 and Sp7. The size of the electron-dense nanospheres was 5 to 50 nm, and the size of nanoprisms varied from 5 to 300 nm. The tentative mechanism responsible for formation of gold nanoparticles is discussed.

  10. Labeled Azospirillum brasilense wild type and excretion-ammonium strains in association with barley roots.

    Science.gov (United States)

    Santos, Adrian Richard Schenberger; Etto, Rafael Mazer; Furmam, Rafaela Wiegand; Freitas, Denis Leandro de; Santos, Karina Freire d'Eça Nogueira; Souza, Emanuel Maltempi de; Pedrosa, Fábio de Oliveira; Ayub, Ricardo Antônio; Steffens, Maria Berenice Reynaud; Galvão, Carolina Weigert

    2017-09-01

    Soil bacteria colonization in plants is a complex process, which involves interaction between many bacterial characters and plant responses. In this work, we labeled Azospirillum brasilense FP2 (wild type) and HM053 (excretion-ammonium) strains by insertion of the reporter gene gusA-kanamycin into the dinitrogenase reductase coding gene, nifH, and evaluated bacteria colonization in barley (Hordeum vulgare). In addition, we determined inoculation effect based on growth promotion parameters. We report an uncommon endophytic behavior of A. brasilense Sp7 derivative inside the root hair cells of barley and highlight the promising use of A. brasilense HM053 as plant growth-promoting bacterium. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Denitrification-derived nitric oxide modulates biofilm formation in Azospirillum brasilense.

    Science.gov (United States)

    Arruebarrena Di Palma, Andrés; Pereyra, Cintia M; Moreno Ramirez, Lizbeth; Xiqui Vázquez, María L; Baca, Beatriz E; Pereyra, María A; Lamattina, Lorenzo; Creus, Cecilia M

    2013-01-01

    Azospirillum brasilense is a rhizobacterium that provides beneficial effects on plants when they colonize roots. The formation of complex bacterial communities known as biofilms begins with the interaction of planktonic cells with surfaces in response to appropriate signals. Nitric oxide (NO) is a signaling molecule implicated in numerous processes in bacteria, including biofilm formation or dispersion, depending on genera and lifestyle. Azospirillum brasilense Sp245 produces NO by denitrification having a role in root growth promotion. We analyzed the role of endogenously produced NO on biofilm formation in A. brasilense Sp245 and in a periplasmic nitrate reductase mutant (napA::Tn5; Faj164) affected in NO production. Cells were statically grown in media with nitrate or ammonium as nitrogen sources and examined for biofilm formation using crystal violet and by confocal laser microscopy. Both strains formed biofilms, but the mutant produced less than half compared with the wild type in nitrate medium showing impaired nitrite production in this condition. NO measurements in biofilm confirmed lower values in the mutant strain. The addition of a NO donor showed that NO influences biofilm formation in a dose-dependent manner and reverses the mutant phenotype, indicating that Nap positively regulates the formation of biofilm in A. brasilense Sp245. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  12. Biological response of Azospirillum spp. to different types of stress

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Sangoquiza Caiza

    2018-01-01

    Full Text Available Azospirillum is one of the most studied free-living rhizobacteria currently of great agricultural interest because of its ability to bind biological nitrogen and produce phytohormones. The present research aimed at the biological response of Azospirillum spp. facing different types of stress. For this purpose, the micro and macro morphological characterization of Azospirillum spp. And its biological response to stress temperature, pH, salinity. The results revealed that the isolates (C2, C3 and C4 of Azospirillum spp. Grow in greater abundance at temperatures between 28-38 °C and pH between 7-8. The C2 and C3 isolates showed good growth up to 3.5 % (m / v NaCl, whereas the C4 strain was less tolerant. These results have biotechnological applicability and are of great importance when defining and controlling the mass production conditions of Azospirillum spp. for future formulations as biofertilizer in several crops of interest in Ecuador.

  13. Co2 +  interaction with Azospirillum brasilense Sp7 cells: a 57Co emission Mössbauer spectroscopic study

    International Nuclear Information System (INIS)

    Kamnev, Alexander A.; Tugarova, Anna V.; Biró, Borbála; Kovács, Krisztina; Homonnay, Zoltán; Kuzmann, Ernő; Vértes, Attila

    2012-01-01

    Preliminary 57 Co emission Mössbauer spectroscopic data were obtained for the soil bacterium Azospirillum brasilense Sp7 (T = 80 K) in frozen 57 Co 2 +  -containing suspensions and in their dried residues. The Mössbauer parameters were compared with those for A. brasilense strain Sp245 differing from strain Sp7 by ecological behaviour. Live cells of both strains showed metabolic transformations of 57 Co 2 +  within an hour. Differences in the parameters observed for the two strains under similar conditions suggest dissimilarities in their metabolic response to Co 2 +  .

  14. Pemacuan Pertumbuhan Melon (Cucumis melo L. dengan Cendawan Mikoriza Arbuskula dan Bakteri Azospirillum sp.

    Directory of Open Access Journals (Sweden)

    Lady Diana Tetelepta

    2016-10-01

    Full Text Available ABSTRACTMelon (Cucumis melo L. is a high economic value horticultural crop that is cultivated in some regions of Indonesia under fertilization management. Application of inorganic fertilizer continuously can reduce soil microbial abundance. One of the soil microbial that promote plant growth is arbuscular mycorrhizal fungi (AMF and Azospirillum sp. The aim of this study was to analysed the effect of AMF and Azospirillum sp. in promoting growth and production of melon. The experiment was carried out in a greenhouse and was arranged in a completely randomized design with five replicates. Five treatments tested were: control, fertilized with NPK, inoculated with AMF, inoculated with Azospirillum sp., inoculated with AMF + Azospirillum sp. The results showed that the effect of AMF on root growth and shoot growth were similar to NPK fertilizer. Azospirillum sp. increased root growth. On the other side, the effect of Azospirillum sp. on shoot growth was similar to NPK fertilizer. However, AMF and Azospirillum sp. inoculation solely increased plant height, fruit weight, fruit diameter, flavor and length of fruit storage. Meanwhile, combination of AMF and Azospirillum sp. increased plant height, root growth, shoot growth, fruit weight, fruit diameter, flavor and length of fruit storage. This study revealed that application of AMF and Azospirillum sp. in melon cultivation was more effective and efficient than NPK fertilizer.Keywords: arbuscular mycorrhizal fungi, Azospirillum sp., Cucumis melo L.

  15. Polymers selection for a liquid inoculant of Azospirillum brasilense ...

    African Journals Online (AJOL)

    In this study, we used a method of accelerated degradation to select a polymer and a concentration to maintain cell stability of a liquid inoculant based on the strain C16 Azospirillum brasilense. A screening at 45°C was made to compare the protectant effect of five polymers on the viability of the strain (p/v): carrageenan ...

  16. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: I. Autotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the microalgae-growth promoting bacterium Azospirillum brasilense on accumulation of total carbohydrates and starch in two species of Chlorella (Chlorella vulgaris and Chlorella sorokiniana), when the bacterium and each microalga were jointly immobilized in alginate beads was studied under autotrophic conditions for 144 h in synthetic medium. The interaction of the bacterium with the microalgae enhanced accumulation of total carbohydrate and starch. Cells of Chlorella accumulated the highest amounts of carbohydrate after incubation for 24h. Yet, this did not coincide with the highest affinity and volumetric productivity measured in these cultures. However, after incubation for 72 h, mainly in jointly immobilized treatments of both microalgae species, the cultures reached their highest total carbohydrate content (mainly as starch) and also the highest affinity and volumetric productivity. These results demonstrate the potential of A. brasilense to affect carbohydrates and starch accumulation in Chlorella spp. when both microorganisms are co-cultured, which can be an important tool for applications of microalgae. Copyright © 2012. Published by Elsevier Inc.

  17. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: II. Heterotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the bacterium Azospirillum brasilense jointly immobilized with Chlorella vulgaris or C. sorokiniana in alginate beads on total carbohydrates and starch was studied under dark and heterotrophic conditions for 144 h in synthetic growth medium supplemented with either d-glucose or Na-acetate as carbon sources. In all treatments, enhanced total carbohydrates and starch content per culture and per cell was obtained after 24h; only jointly immobilized C. vulgaris growing on d-glucose significantly increased total carbohydrates and starch content after 96 h. Enhanced accumulation of carbohydrate and starch under jointly immobilized conditions was variable with time of sampling and substrate used. Similar results occurred when the microalgae was immobilized alone. In both microalgae growing on either carbon sources, the bacterium promoted accumulation of carbohydrates and starch; when the microalgae were immobilized alone, they used the carbon sources for cell multiplication. In jointly immobilized conditions with Chlorella spp., affinity to carbon source and volumetric productivity and yield were higher than when Chlorella spp. were immobilized alone; however, the growth rate was higher in microalgae immobilized alone. This study demonstrates that under heterotrophic conditions, A. brasilense promotes the accumulation of carbohydrates in two strains Chlorella spp. under certain time-substrate combinations, producing mainly starch. As such, this bacterium is a biological factor that can change the composition of compounds in microalgae in dark, heterotrophic conditions. Copyright © 2012. Published by Elsevier Inc.

  18. Pertumbuhan Padi Varietas Ciherang Setelah Diinokulasi dengan Azospirillum Mutan Multifungsi

    Directory of Open Access Journals (Sweden)

    Edy Listanto

    2016-08-01

    Full Text Available Modern agriculture is very closely related to the application of fertilizer to induce plants grow. The application of bio-fertilizers is expected to reduce the negative impact of chemical fertilizers. The purpose of this study was to determine the effect of multi-functional Azospirillum N2 fixation, P solubility and IAA production on the growth of Ciherang rice in pot experiment in greenhouse BB Biogen. The experiment treatment were 3 types of inoculation (non-inoculation, inoculation using wildtype Aj Bandung 6.4.1.2 and the mutant isolate of AJM 3.7.1.14 , and 4 levels of fertilizer application (non-fertilization, a quarter dose, a half dose, and the real dose of fertilization on rice in lowland. The Azospirillum isolates were used wildtype isolate Aj Bandung 6.4.1.2 and mutant isolate AJM 3.7.1.14 that was isolated and mutated using ethyl methanesulfonate (EMS in BB Biogen. Seeds of Ciherang rice were inoculated using Azospirillum at cell density 106 cell/ml in different seedling tray. After 14 days, the seedlings were transferred to planting pots which consist of 3 plants per pot. Parameters observed were plant height, number of tillers, number of panicles per hill, wet and dry weight of panicles per hill, weight of 100 seeds, N and P content of the stover. The results showed that both wild-Azospirillum and mutant inoculum had no effect on the vegetative growth of Ciherang, but showed significant effect on the number of panicle per hill, grain weight per hill and dry weight of seeds per panicle. The use of Azospirillum and N fertilizer combination affected the growth and rice yields, also reduced chemical fertilizer application.

  19. The role of the antimicrobial compound 2,4-diacetylphloroglucinol in the impact of biocontrol Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators.

    Science.gov (United States)

    Couillerot, Olivier; Combes-Meynet, Emeline; Pothier, Joël F; Bellvert, Floriant; Challita, Elita; Poirier, Marie-Andrée; Rohr, René; Comte, Gilles; Moënne-Loccoz, Yvan; Prigent-Combaret, Claire

    2011-06-01

    Pseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (Phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. Here, the effects of synthetic Phl and Phl(+) Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators were investigated. Most A. brasilense strains were moderately sensitive to Phl. In vitro, Phl induced accumulation of carotenoids and poly-β-hydroxybutyrate-like granules, cytoplasmic membrane damage and growth inhibition in A. brasilense Cd. Experiments with P. fluorescens F113 and a Phl(-) mutant indicated that Phl production ability contributed to in vitro growth inhibition of A. brasilense Cd and Sp245. Under gnotobiotic conditions, each of the three strains, P. fluorescens F113 and A. brasilense Cd and Sp245, stimulated wheat growth. Co-inoculation of A. brasilense Sp245 and Pseudomonas resulted in the same level of phytostimulation as in single inoculations, whereas it abolished phytostimulation when A. brasilense Cd was used. Pseudomonas Phl production ability resulted in lower Azospirillum cell numbers per root system (based on colony counts) and restricted microscale root colonization of neighbouring Azospirillum cells (based on confocal microscopy), regardless of the A. brasilense strain used. Therefore, this work establishes that Phl(+) pseudomonads have the potential to interfere with A. brasilense phytostimulators on roots and with their plant growth promotion capacity.

  20. 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.

  1. Nitric oxide metabolism and indole acetic acid biosynthesis cross-talk in Azospirillum brasilense SM.

    Science.gov (United States)

    Koul, Vatsala; Tripathi, Chandrakant; Adholeya, Alok; Kochar, Mandira

    2015-04-01

    Production of nitric oxide (NO) and the presence of NO metabolism genes, nitrous oxide reductase (nosZ), nitrous oxide reductase regulator (nosR) and nitric oxide reductase (norB) were identified in the plant-associated bacterium (PAB) Azospirillum brasilense SM. NO presence was confirmed in all overexpressing strains, while improvement in the plant growth response of these strains was mediated by increased NO and indole-3-acetic acid (IAA) levels in the strains. Electron microscopy showed random distribution to biofilm, with surface colonization of pleiomorphic Azospirilla. Quantitative IAA estimation highlighted a crucial role of nosR and norBC in regulating IAA biosynthesis. The NO quencher and donor reduced/blocked IAA biosynthesis by all strains, indicating their common regulatory role in IAA biosynthesis. Tryptophan (Trp) and l-Arginine (Arg) showed higher expression of NO genes tested, while in the case of ipdC, only Trp and IAA increased expression, while Arg had no significant effect. The highest nosR expression in SMnosR in the presence of IAA and Trp, along with its 2-fold IAA level, confirmed the relationship of nosR overexpression with Trp in increasing IAA. These results indicate a strong correlation between IAA and NO in A. brasilense SM and suggest the existence of cross-talk or shared signaling mechanisms in these two growth regulators. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  2. Survey the Effect of Mycorrhiza and Azospirillum of Wheat Cultivars Resistance in Yellow Rust

    Directory of Open Access Journals (Sweden)

    M. Jiriaie

    2017-01-01

    Full Text Available Introduction: Wheat is one of the major agricultural crops with respect to human nutrition. It is cultivated over a wide range of environments, because of wide adaptation to diverse environmental conditions. In Iran, 6.2 million hectares are under wheat cultivation, of which 33% is irrigated and 67% is rain-fed, the irrigated wheat growing areas (2 million hectares are located mostly in southern, central and east of Iran Production of crops is under the influence of plant genetic structure, environmental conditions and their interactions. Biotic and abiotic stresses are considered to lower production. Among the biotic stress, the fungal disease is the main factor limiting production of crop plants in hot and humid regions. Stripe rust was not a serious economic concern to the wheat industry for most of the 1990’s due to the use of resistant varieties. However, by 2003 it had developed into a significant issue, particularly as new path types evolved. Even in the dry years of 2003 and 2004, stripe rust cost growers significant income. Provide country's need for wheat as a strategic product, meanwhile, production is free from chemical fungicide is a high but achievable goal. So in order to achieve fertilizer and fungicide resources that in addition to having no adverse effects on consumers and the environment, has been economically able to provide nutrition need of crop plant, is very important. Materials and Methods: With this approach, to survey the effect of Mycorrhiza and Azospirillum in resistance to yellow rust in wheat cultivars, an experiment was conducted at the research station of the Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on a randomized complete block design with three replications. The treatments include of Mycorrhiza fungi in three levels (without application of Mycorrhiza strain and using strain Glomus intraradices and Glomus mosseae, Azospirillum lipoferum bacterium in two

  3. Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium Azospirillum spp.

    Science.gov (United States)

    Rodriguez, Hilda; Gonzalez, Tania; Goire, Isabel; Bashan, Yoav

    2004-11-01

    In vitro gluconic acid formation and phosphate solubilization from sparingly soluble phosphorus sources by two strains of the plant growth-promoting bacteria A. brasilense (Cd and 8-I) and one strain of A. lipoferum JA4 were studied. Strains of A. brasilense were capable of producing gluconic acid when grown in sparingly soluble calcium phosphate medium when their usual fructose carbon source is amended with glucose. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. To a greater extent, gluconic acid production and pH reduction were observed for A. lipoferum JA4. For the three strains, clearing halos were detected on solid medium plates with calcium phosphate. This is the first report of in vitro gluconic acid production and direct phosphate solubilization by A. brasilense and the first report of P solubilization by A. lipoferum. This adds to the very broad spectrum of plant growth-promoting abilities of this genus.

  4. Inoculation of maize with Azospirillum brasilense in the seed furrow

    Directory of Open Access Journals (Sweden)

    Tâmara Prado de Morais

    2016-06-01

    Full Text Available ABSTRACT Several studies addressing the inoculation of cereals with diazotrophic microorganisms can be found in the literature. However, in many experiments, investigators have overlooked the feasibility of applying these microorganisms to the furrow together with the seed, and the effect of bacterial concentration on phytostimulation. The aim of this work was to evaluate the effect of doses of an inoculant based on Azospirillum brasilense, applied to the seed furrow when planting maize, combined with different doses of nitrogen fertiliser. The experiment was carried out in the field, in soil of the cerrado region of Brazil. An experimental design of randomised blocks in bands was adopted, comprising nitrogen (40, 100, 200 and 300 kg ha-1 and doses of an A. brasilense-based liquid inoculant applied to the seed furrow (0, 100, 200, 300 and 400 mL ha-1. The dose of 200 mL ha-1Azospirillum was noteworthy for grain production. This is the first report of the effective application of Azospirillum in the seed furrow when planting maize in the cerrado region of Brazil.

  5. Phytohormones and induction of plant-stress tolerance and defense genes by seed and foliar inoculation with Azospirillum brasilense cells and metabolites promote maize growth.

    Science.gov (United States)

    Fukami, Josiane; Ollero, Francisco Javier; Megías, Manuel; Hungria, Mariangela

    2017-12-01

    Azospirillum spp. are plant-growth-promoting bacteria used worldwide as inoculants for a variety of crops. Among the beneficial mechanisms associated with Azospirillum inoculation, emphasis has been given to the biological nitrogen fixation process and to the synthesis of phytohormones. In Brazil, the application of inoculants containing A. brasilense strains Ab-V5 and Ab-V6 to cereals is exponentially growing and in this study we investigated the effects of maize inoculation with these two strains applied on seeds or by leaf spray at the V2.5 stage growth-a strategy to relieve incompatibility with pesticides used for seed treatment. We also investigate the effects of spraying the metabolites of these two strains at V2.5. Maize growth was promoted by the inoculation of bacteria and their metabolites. When applied via foliar spray, although A. brasilense survival on leaves was confirmed by confocal microscopy and cell recovery, few cells were detected after 24 h, indicating that the effects of bacterial leaf spray might also be related to their metabolites. The major molecules detected in the supernatants of both strains were indole-3-acetic acid, indole-3-ethanol, indole-3-lactic acid and salicylic acid. RT-PCR of genes related to oxidative stress (APX1, APX2, CAT1, SOD2, SOD4) and plant defense (pathogenesis-related PR1, prp2 and prp4) was evaluated on maize leaves and roots. Differences were observed according to the gene, plant tissue, strain and method of application, but, in general, inoculation with Azospirillum resulted in up-regulation of oxidative stress genes in leaves and down-regulation in roots; contrarily, in general, PR genes were down-regulated in leaves and up-regulated in roots. Emphasis should be given to the application of metabolites, especially of Ab-V5 + Ab-V6 that in general resulted in the highest up-regulation of oxidative-stress and PR genes both in leaves and in roots. We hypothesize that the benefits of inoculation of Azospirillum on

  6. Screening on Gibberellic Acid Producing Activity of Azospirillum Isolates

    International Nuclear Information System (INIS)

    Shun Lai Ei; Khin Mya Lwin; Myo Myint

    2010-12-01

    Six strains of Azopirillum spp were isolated from rice, sugarcane, corn, maize, sunflower and pepper roots and screened the gibberellic acid productivity. Only three strains of Azospirillum species showed the activity and were indentified by cultural, biochemical and drug sensitivity patterns. Among them,one strain isolated from rice root can produce microbial gibberellic acid. It showed greenish yellow colour in chromatogram under UV absorption. This screening method was studied from 1 to 14 days incubation. Qualitative measurement of GA productivity was determined by thin layer chromatography.

  7. Compatibility of Azospirillum brasilense and Pseudomonas fluorescens in growth promotion of groundnut ( Arachis hypogea L.).

    Science.gov (United States)

    Prasad, Andhare A; Babu, Subramanian

    2017-01-01

    We attempted to study the compatibility among plant beneficial bacteria in the culture level by growing them near in the nutrient agar plates. Among all the bacteria tested, Rhizobium was found to inhibit the growth of other bacteria. From the compatible group of PGPR, we have selected one biofertilizer (Azospirillum brasilense strain TNAU) and one biocontrol agent (Pseudomonas fluorescens strain PF1) for further studies in the pot culture. We have also developed a bioformulation which is talc powder based, for individual bacteria and mixed culture. This formulation was used as seed treatment, soil application, seedling root dip and foliar spray in groundnut crop in vitro germination conditions. A. brasilense was found to enhance the tap root growth and P. fluorescens, the lateral root growth. The other growth parameters like shoot growth, number of leaves were enhanced by the combination of both of the bacteria than their individual formulations. Among the method of application tested in our study, soil application was found to be the best in yielding better results of plant growth promotion.

  8. Compatibility of Azospirillum brasilense and Pseudomonas fluorescens in growth promotion of groundnut ( Arachis hypogea L.

    Directory of Open Access Journals (Sweden)

    ANDHARE A. PRASAD

    Full Text Available ABSTRACT We attempted to study the compatibility among plant beneficial bacteria in the culture level by growing them near in the nutrient agar plates. Among all the bacteria tested, Rhizobium was found to inhibit the growth of other bacteria. From the compatible group of PGPR, we have selected one biofertilizer (Azospirillum brasilense strain TNAU and one biocontrol agent (Pseudomonas fluorescens strain PF1 for further studies in the pot culture. We have also developed a bioformulation which is talc powder based, for individual bacteria and mixed culture. This formulation was used as seed treatment, soil application, seedling root dip and foliar spray in groundnut crop in vitro germination conditions. A. brasilense was found to enhance the tap root growth and P. fluorescens, the lateral root growth. The other growth parameters like shoot growth, number of leaves were enhanced by the combination of both of the bacteria than their individual formulations. Among the method of application tested in our study, soil application was found to be the best in yielding better results of plant growth promotion.

  9. Aislamiento e identificación de cepas de Azospirillum sp. en pasto guinea (Panicum maximum Jacq. del Valle del Cesar Isolation and identification of Azospirillum sp. in Guinea grass (Panicum maximum Jacq. of the Valle del Cesar

    Directory of Open Access Journals (Sweden)

    Diana M Cárdenas

    2010-09-01

    differences, which indicates that this bacterium can maintain its population under stress conditions by different physiological mechanisms. From these samples 16 isolations were obtained belonging to the Azospirillum genus in which their acetylene-reduction activity was evaluated as indicator of biological nitrogen fixation and their capacity in the production of indolic compounds as plant growth promoters. The strains SRGM2, SRGM3 and SRGM4, obtained from rhizospheric soil samples of Guinea grass of the Experimental Station Motilonia of Corpoica, Agustín Codazzi municipality, Cesar department, were selected. These isolations were molecularly characterized by the gen 16S rRNA and according to the BLAST analysis in the GenBank database and showed 93% similarity with A. lipoferum (SRGM2 and SRGM3 and 94% with A. brasilense (SRGM4.

  10. Metabolic adaptations of Azospirillum brasilense to oxygen stress by cell-to-cell clumping and flocculation.

    Science.gov (United States)

    Bible, Amber N; Khalsa-Moyers, Gurusahai K; Mukherjee, Tanmoy; Green, Calvin S; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B; Alexandre, Gladys

    2015-12-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Characterization of two trpE genes encoding anthranilate synthase α-subunit in Azospirillum brasilense

    International Nuclear Information System (INIS)

    Ge Shimei; Xie Baoen; Chen Sanfeng

    2006-01-01

    The previous report from our laboratory has recently identified a new trpE gene (termed trpE 2 ) which exists independently in Azospirillum brasilense Yu62. In this study, amplification of trpE(G) (termed trpE 1 (G) here) confirmed that there are two copies of trpE gene, one trpE being fused into trpG while the other trpE existed independently. This is First report to suggest that two copies of the trpE gene exist in this bacterium. Comparison of the nucleotide sequence demonstrated that putative leader peptide, terminator, and anti-terminator were found upstream of trpE 1 (G) while these sequence features did not exist in front of trpE 2 . The β-galactosidase activity of an A. brasilense strain carrying a trpE 2 -lacZ fusion remained constant at different tryptophan concentrations, but the β-galactosidase activity of the same strain carrying a trpE 1 (G)-lacZ fusion decreased as the tryptophan concentration increased. These data suggest that the expression of trpE 1 (G) is regulated at the transcriptional level by attenuation while trpE 2 is constantly expressed. The anthranilate synthase assays with trpE 1 (G) - and trpE 2 - mutants demonstrated that TrpE 1 (G) fusion protein is feedback inhibited by tryptophan while TrpE 2 protein is not. We also found that both trpE 1 (G) and trpE 2 gene products were involved in IAA synthesis

  12. Change in the Content of Salicylic Acid and in the Activities of Phenylalanine Ammonia-Lyase and Catalase in Wheat Seedling Roots Under the Effect of Azospirillum Lectins

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    Alen'kina S.A.

    2012-05-01

    Full Text Available We investigated the time course of changes in the endogenous content of salicylic acid, the ratio between the acid's free and bound forms, and changes in the activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the effect of the lectins of two strains of the associative nitrogen-fixing bacterium Azospirillum: A. brasilense Sp7 and its mutant defective in lectin activity, A. brasilense Sp7.2.3. Differences in plant response to the action of the lectins from these two strains were established. On the basis of the obtained data, a model was proposed for lectin-assisted induction of resistance, according to which the lectin effect on the roots of seedlings results in accumulation of free salicylic acid, which inhibits catalase activity, ultimately leading to accumulation of hydrogen peroxide and to formation of induced resistance.

  13. Accumulation of fatty acids in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoAcarboxylase, temperature, and co-immobilization with Azospirillum brasilense [corrected].

    Science.gov (United States)

    Leyva, Luis A; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  14. Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase, temperature, and co-immobilization with Azospirillum brasilense

    Science.gov (United States)

    Leyva, Luis A.; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E.

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  15. Study of the rhizobacterium Azospirillum brasilense Sp245 using Mössbauer spectroscopy with a high velocity resolution: Implication for the analysis of ferritin-like iron cores

    Science.gov (United States)

    Alenkina, I. V.; Oshtrakh, M. I.; Tugarova, A. V.; Biró, B.; Semionkin, V. A.; Kamnev, A. A.

    2014-09-01

    The results of a comparative study of two samples of the rhizobacterium Azospirillum brasilense (strain Sp245) prepared in different conditions and of human liver ferritin using Mössbauer spectroscopy with a high velocity resolution demonstrated the presence of ferritin-like iron (i.e. iron similar to that found in ferritin-like proteins) in the bacterium. Mössbauer spectra of these samples were fitted in two ways: as a rough approximation using a one quadrupole doublet fit (the homogeneous iron core model) and using a superposition of quadrupole doublets (the heterogeneous iron core model). Both results demonstrated differences in the Mössbauer parameters for mammalian ferritin and for bacterial ferritin-like iron. Moreover, some differences in the Mössbauer parameters were observed between the two samples of A. brasilense Sp245 related to the differences in their preparation conditions.

  16. Application of the Indirect Immunoperoxidase Stain Technique to the Flagella of Azospirillum brasilense

    Science.gov (United States)

    Hall, Patrick G.; Krieg, Noel R.

    1984-01-01

    An indirect immunoperoxidase stain was used to demonstrate by electron microscopy that an antigenic difference exists between the polar flagellum and the lateral flagella of Azospirillum brasilense ATCC 29145. Images PMID:16346482

  17. Enhanced activity of ADP glucose pyrophosphorylase and formation of starch induced by Azospirillum brasilense in Chlorella vulgaris.

    Science.gov (United States)

    Choix, Francisco J; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E

    2014-05-10

    ADP-glucose pyrophosphorylase (AGPase) regulates starch biosynthesis in higher plants and microalgae. This study measured the effect of the bacterium Azospirillum brasilense on AGPase activity in the freshwater microalga Chlorella vulgaris and formation of starch. This was done by immobilizing both microorganisms in alginate beads, either replete with or deprived of nitrogen or phosphorus and all under heterotrophic conditions, using d-glucose or Na-acetate as the carbon source. AGPase activity during the first 72h of incubation was higher in C. vulgaris when immobilized with A. brasilense. This happened simultaneously with higher starch accumulation and higher carbon uptake by the microalgae. Either carbon source had similar effects on enzyme activity and starch accumulation. Starvation either by N or P had the same pattern on AGPase activity and starch accumulation. Under replete conditions, the population of C. vulgaris immobilized alone was higher than when immobilized together, but under starvation conditions A. brasilense induced a larger population of C. vulgaris. In summary, adding A. brasilense enhanced AGPase activity, starch formation, and mitigation of stress in C. vulgaris. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Inoculation with Bacillus subtilis and Azospirillum brasilense produces abscisic acid that reduces IRT1-mediated cadmium uptake of roots.

    Science.gov (United States)

    Xu, Qianru; Pan, Wei; Zhang, Ranran; Lu, Qi; Xue, Wanlei; Wu, Cainan; Song, Bixiu; Du, Shaoting

    2018-05-08

    Cadmium (Cd) contamination of agricultural soils represents a serious risk to crop safety. A new strategy using abscisic acid (ABA)-generating bacteria, Bacillus subtilis or Azospirillum brasilense, was developed to reduce the Cd accumulation in plants grown in Cd-contaminated soil. Inoculation with either bacterium resulted in a pronounced increase in the ABA level in wild-type Arabidopsis Col-0 plants, accompanied by a decrease in Cd levels in plant tissues, which mitigated the Cd toxicity. As a consequence, the growth of plants exposed to Cd was improved. Nevertheless, B. subtilis and A. brasilense inoculation had little effect on Cd levels and toxicity in the ABA-insensitive mutant snrk 2.2/2.3, indicating that the action of ABA is required for these bacteria to reduce Cd accumulation in plants. Furthermore, inoculation with either B. subtilis or A. brasilense down-regulated the expression of IRT1 (IRON-REGULATED TRANSPORTER 1) in the roots of wild-type plants and had little effect on Cd levels in the IRT1-knockout mutants irt1-1 and irt1-2. In summary, we conclude that B. subtilis and A. brasilense can reduce Cd levels in plants via an IRT1-dependent ABA-mediated mechanism.

  19. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense

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    C.Y. Nishikawa

    2012-02-01

    Full Text Available Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ54 co-factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL. A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH4Cl but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription.

  20. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, C.Y.; Araújo, L.M.; Kadowaki, M.A.S.; Monteiro, R.A.; Steffens, M.B.R.; Pedrosa, F.O.; Souza, E.M.; Chubatsu, L.S. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil)

    2012-01-27

    Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ{sup 54} factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH{sub 4}Cl) but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription.

  1. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense.

    Science.gov (United States)

    Nishikawa, C Y; Araújo, L M; Kadowaki, M A S; Monteiro, R A; Steffens, M B R; Pedrosa, F O; Souza, E M; Chubatsu, L S

    2012-02-01

    Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ(54) co-factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH(4)Cl) but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription.

  2. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense

    International Nuclear Information System (INIS)

    Nishikawa, C.Y.; Araújo, L.M.; Kadowaki, M.A.S.; Monteiro, R.A.; Steffens, M.B.R.; Pedrosa, F.O.; Souza, E.M.; Chubatsu, L.S.

    2012-01-01

    Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ 54 factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH 4 Cl) but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription

  3. Accessing inoculation methods of maize and wheat with Azospirillum brasilense.

    Science.gov (United States)

    Fukami, Josiane; Nogueira, Marco Antonio; Araujo, Ricardo Silva; Hungria, Mariangela

    2016-03-01

    The utilization of inoculants containing Azospirillum is becoming more popular due to increasing reports of expressive gains in grain yields. However, incompatibility with pesticides used in seed treatments represents a main limitation for a successful inoculation. Therefore, in this study we searched for alternatives methods for seed inoculation of maize and wheat, aiming to avoid the direct contact of bacteria with pesticides. Different doses of inoculants containing Azospirillum brasilense were employed to perform inoculation in-furrow, via soil spray at sowing and via leaf spray after seedlings had emerged, in comparison to seed inoculation. Experiments were conducted first under greenhouse controlled conditions and then confirmed in the field at different locations in Brazil. In the greenhouse, most parameters measured responded positively to the largest inoculant dose used in foliar sprays, but benefits could also be observed from both in-furrow and soil spray inoculation. However, our results present evidence that field inoculation with plant-growth promoting bacteria must consider inoculant doses, and point to the need of fine adjustments to avoid crossing the threshold of growth stimulation and inhibition. All inoculation techniques increased the abundance of diazotrophic bacteria in plant tissues, and foliar spray improved colonization of leaves, while soil inoculations favored root and rhizosphere colonization. In field experiments, inoculation with A. brasilense allowed for a 25 % reduction in the need for N fertilizers. Our results have identified alternative methods of inoculation that were as effective as the standard seed inoculation that may represent an important strategy to avoid the incompatibility between inoculant bacteria and pesticides employed for seed treatment.

  4. Bacteriophage Prevalence in the Genus Azospirillum and Analysis of the First Genome Sequence of an Azospirillum brasilense Integrative Phage▿

    Science.gov (United States)

    Boyer, Mickaël; Haurat, Jacqueline; Samain, Sylvie; Segurens, Béatrice; Gavory, Frédérick; González, Víctor; Mavingui, Patrick; Rohr, René; Bally, René; Wisniewski-Dyé, Florence

    2008-01-01

    The prevalence of bacteriophages was investigated in 24 strains of four species of plant growth-promoting rhizobacteria belonging to the genus Azospirillum. Upon induction by mitomycin C, the release of phage particles was observed in 11 strains from three species. Transmission electron microscopy revealed two distinct sizes of particles, depending on the identity of the Azospirillum species, typical of the Siphoviridae family. Pulsed-field gel electrophoresis and hybridization experiments carried out on phage-encapsidated DNAs revealed that all phages isolated from A. lipoferum and A. doebereinerae strains had a size of about 10 kb whereas all phages isolated from A. brasilense strains displayed genome sizes ranging from 62 to 65 kb. Strong DNA hybridizing signals were shown for most phages hosted by the same species whereas no homology was found between phages harbored by different species. Moreover, the complete sequence of the A. brasilense Cd bacteriophage (ΦAb-Cd) genome was determined as a double-stranded DNA circular molecule of 62,337 pb that encodes 95 predicted proteins. Only 14 of the predicted proteins could be assigned functions, some of which were involved in DNA processing, phage morphogenesis, and bacterial lysis. In addition, the ΦAb-Cd complete genome was mapped as a prophage on a 570-kb replicon of strain A. brasilense Cd, and a region of 27.3 kb of ΦAb-Cd was found to be duplicated on the 130-kb pRhico plasmid previously sequenced from A. brasilense Sp7, the parental strain of A. brasilense Cd. PMID:18065619

  5. Bacteriophage prevalence in the genus Azospirillum and analysis of the first genome sequence of an Azospirillum brasilense integrative phage.

    Science.gov (United States)

    Boyer, Mickaël; Haurat, Jacqueline; Samain, Sylvie; Segurens, Béatrice; Gavory, Frédérick; González, Víctor; Mavingui, Patrick; Rohr, René; Bally, René; Wisniewski-Dyé, Florence

    2008-02-01

    The prevalence of bacteriophages was investigated in 24 strains of four species of plant growth-promoting rhizobacteria belonging to the genus Azospirillum. Upon induction by mitomycin C, the release of phage particles was observed in 11 strains from three species. Transmission electron microscopy revealed two distinct sizes of particles, depending on the identity of the Azospirillum species, typical of the Siphoviridae family. Pulsed-field gel electrophoresis and hybridization experiments carried out on phage-encapsidated DNAs revealed that all phages isolated from A. lipoferum and A. doebereinerae strains had a size of about 10 kb whereas all phages isolated from A. brasilense strains displayed genome sizes ranging from 62 to 65 kb. Strong DNA hybridizing signals were shown for most phages hosted by the same species whereas no homology was found between phages harbored by different species. Moreover, the complete sequence of the A. brasilense Cd bacteriophage (phiAb-Cd) genome was determined as a double-stranded DNA circular molecule of 62,337 pb that encodes 95 predicted proteins. Only 14 of the predicted proteins could be assigned functions, some of which were involved in DNA processing, phage morphogenesis, and bacterial lysis. In addition, the phiAb-Cd complete genome was mapped as a prophage on a 570-kb replicon of strain A. brasilense Cd, and a region of 27.3 kb of phiAb-Cd was found to be duplicated on the 130-kb pRhico plasmid previously sequenced from A. brasilense Sp7, the parental strain of A. brasilense Cd.

  6. Genome Sequence of Azospirillum brasilense CBG497 and Comparative Analyses of Azospirillum Core and Accessory Genomes provide Insight into Niche Adaptation

    Science.gov (United States)

    Wisniewski-Dyé, Florence; Lozano, Luis; Acosta-Cruz, Erika; Borland, Stéphanie; Drogue, Benoît; Prigent-Combaret, Claire; Rouy, Zoé; Barbe, Valérie; Mendoza Herrera, Alberto; González, Victor; Mavingui, Patrick

    2012-01-01

    Bacteria of the genus Azospirillum colonize roots of important cereals and grasses, and promote plant growth by several mechanisms, notably phytohormone synthesis. The genomes of several Azospirillum strains belonging to different species, isolated from various host plants and locations, were recently sequenced and published. In this study, an additional genome of an A. brasilense strain, isolated from maize grown on an alkaline soil in the northeast of Mexico, strain CBG497, was obtained. Comparative genomic analyses were performed on this new genome and three other genomes (A. brasilense Sp245, A. lipoferum 4B and Azospirillum sp. B510). The Azospirillum core genome was established and consists of 2,328 proteins, representing between 30% to 38% of the total encoded proteins within a genome. It is mainly chromosomally-encoded and contains 74% of genes of ancestral origin shared with some aquatic relatives. The non-ancestral part of the core genome is enriched in genes involved in signal transduction, in transport and in metabolism of carbohydrates and amino-acids, and in surface properties features linked to adaptation in fluctuating environments, such as soil and rhizosphere. Many genes involved in colonization of plant roots, plant-growth promotion (such as those involved in phytohormone biosynthesis), and properties involved in rhizosphere adaptation (such as catabolism of phenolic compounds, uptake of iron) are restricted to a particular strain and/or species, strongly suggesting niche-specific adaptation. PMID:24705077

  7. Genome Sequence of Azospirillum brasilense CBG497 and Comparative Analyses of Azospirillum Core and Accessory Genomes provide Insight into Niche Adaptation

    Directory of Open Access Journals (Sweden)

    Victor González

    2012-09-01

    Full Text Available Bacteria of the genus Azospirillum colonize roots of important cereals and grasses, and promote plant growth by several mechanisms, notably phytohormone synthesis. The genomes of several Azospirillum strains belonging to different species, isolated from various host plants and locations, were recently sequenced and published. In this study, an additional genome of an A. brasilense strain, isolated from maize grown on an alkaline soil in the northeast of Mexico, strain CBG497, was obtained. Comparative genomic analyses were performed on this new genome and three other genomes (A. brasilense Sp245, A. lipoferum 4B and Azospirillum sp. B510. The Azospirillum core genome was established and consists of 2,328 proteins, representing between 30% to 38% of the total encoded proteins within a genome. It is mainly chromosomally-encoded and contains 74% of genes of ancestral origin shared with some aquatic relatives. The non-ancestral part of the core genome is enriched in genes involved in signal transduction, in transport and in metabolism of carbohydrates and amino-acids, and in surface properties features linked to adaptation in fluctuating environments, such as soil and rhizosphere. Many genes involved in colonization of plant roots, plant-growth promotion (such as those involved in phytohormone biosynthesis, and properties involved in rhizosphere adaptation (such as catabolism of phenolic compounds, uptake of iron are restricted to a particular strain and/or species, strongly suggesting niche-specific adaptation.

  8. Bacterium oxidizing carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kistner, A

    1953-01-01

    Present-day knowledge of the microbiological oxidation of carbon monoxide is based on doubtful observations and imperfect experimental procedures. By making use of shake cultures in contact with gas mixtures containing high concentrations of CO and by employing liquid enrichment media with a low content of organic matter and solid media of the same composition with not more than 1.2% agar, it proved possible to isolate a co-oxidizing bacterium of the genus hydrogenomonas from sewage sludge. For the first time irrefutable proof has been given of the oxidation of carbon monoxide by a pure culture of a bacterium, both in growing cultures and in resting cell suspensions. 12 references.

  9. Irrigated wheat subjected to inoculation with Azospirillum brasilense and nitrogen doses as top-dressing

    Directory of Open Access Journals (Sweden)

    Cleiton J. Alves

    Full Text Available ABSTRACT The use of Azospirillum brasilense in the wheat crop still presents contradictory results; thus, it is necessary to identify ideal conditions to obtain satisfactory results. The objective of this study was to investigate the interaction between Azospirillum brasilense and nitrogen doses in a wheat cultivar, conducted with irrigation in the Cerrado region of Mato Grosso do Sul. The experimental design was randomized blocks with a 4 x 2 factorial scheme, four nitrogen doses (0, 40, 80 and 120 kg ha-1 applied as top-dressing, associated or not with inoculation of wheat seeds with Azospirillum brasilense. The results show that there was no interaction between N and inoculation. The isolated effect of Azospirillum brasilense promotes an increase in plant height and number of grains per spike. Nitrogen doses promotes significant increases in leaf N content, plant height, number of grains per spike, number of spikes per square meter and grain yield. The conditions under which the experiment was conducted favored the development of the crop, not interfering with grain yield due the inoculation with Azospirillum brasilense.

  10. Electrostatic beneficiation of coal

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, M.K.; Tennal, K.B.; Lindquist, D.

    1994-10-01

    Dry physical beneficiation of coal has many advantages over wet cleaning methods and post combustion flue gas cleanup processes. The dry beneficiation process is economically competitive and environmentally safe and has the potential of making vast amounts of US coal reserves available for energy generation. While the potential of the electrostatic beneficiation has been studied for many years in laboratories and in pilot plants, a successful full scale electrostatic coal cleaning plant has not been commercially realized yet. In this paper the authors review some of the technical problems that are encountered in this method and suggest possible solutions that may lead toward its full utilization in cleaning coal.

  11. Beneficial Insects: Beetles

    OpenAIRE

    Hodgson, Erin W.; Patterson, Ron

    2007-01-01

    There are many beneficial beetles in Utah besides lady beetles or ladybugs. Beetles can significantly reduce common insect and weed problems and in some cases eliminate the need for chemical control. Examples of beneficial beetles include: ground beetles, rove beetles, tiger beetles and tortoise beetles. Many of these beetles are native to Utah, while others have been purposely introduced to help control damage from exotic insect and weed pests.

  12. Directed mutagenesis affects recombination in Azospirillum brasilense nif genes

    Directory of Open Access Journals (Sweden)

    C.P. Nunes

    2000-12-01

    Full Text Available In order to improve the gene transfer/mutagenesis system for Azospirillum brasilense, gene-cartridge mutagenesis was used to replace the nifD gene with the Tn5 kanamycin resistance gene. The construct was transferred to A. brasilense by electrotransformation. Of the 12 colonies isolated using the suicide plasmid pSUP202 as vector, only four did not show vector integration into the chromosome. Nevertheless, all 12 colonies were deficient in acetylene reduction, indicating an Nif- phenotype. Four Nif- mutants were analyzed by Southern blot, using six different probes spanning the nif and Km r genes and the plasmid vector. Apparently, several recombination events occurred in the mutant genomes, probably caused mainly by gene disruption owing to the mutagenesis technique used: resistance gene-cartridge mutagenesis combined with electrotransformation.Com o objetivo de melhorar os sistemas de transferência gênica e mutagênese para Azospirillum brasilense, a técnica de mutagênese através do uso de um gene marcador ("gene-cartridge mutagenesis" foi utilizada para substituir a região genômica de A. brasilense correspondente ao gene nifD por um segmento de DNA do transposon Tn5 contendo o gene que confere resistência ao antibiótico canamicina. A construção foi transferida para a linhagem de A. brasilense por eletrotransformação. Doze colônias transformantes foram isoladas com o plasmídeo suicida pSUP202 servindo como vetor. Dessas, somente quatro não possuíam o vetor integrado no cromossomo da bactéria. Independentemente da integração ou não do vetor, as 12 colônias foram deficientes na redução do gás acetileno, evidenciando o fenótipo Nif -. Quatro mutantes Nif - foram analisados através da técnica de Southern blot, utilizando-se seis diferentes fragmentos contendo genes nif, de resistência à canamicina e do vetor como sondas. Os resultados sugerem a ocorrência de eventos recombinacionais variados no genoma dos mutantes. A

  13. Plant root transcriptome profiling reveals a strain-dependent response during Azospirillum-rice cooperation

    Directory of Open Access Journals (Sweden)

    Benoît eDrogue

    2014-11-01

    Full Text Available Cooperation involving Plant Growth-Promoting Rhizobacteria results in improvements of plant growth and health. While pathogenic and symbiotic interactions are known to induce transcriptional changes for genes related to plant defence and development, little is known about the impact of phytostimulating rhizobacteria on plant gene expression. This study aims at identifying genes significantly regulated in rice roots upon Azospirillum inoculation, considering possible favored interaction between a strain and its original host cultivar. Genome-wide analyses of Oryza sativa japonica cultivars Cigalon and Nipponbare were performed, by using microarrays, seven days post inoculation with A. lipoferum 4B (isolated from Cigalon or Azospirillum sp. B510 (isolated from Nipponbare and compared to the respective non-inoculated condition. A total of 7,384 genes were significantly regulated, which represent about 16 % of total rice genes. A set of 34 genes is regulated by both Azospirillum strains in both cultivars, including a gene orthologous to PR10 of Brachypodium, and these could represent plant markers of Azospirillum-rice interactions. The results highlight a strain-dependent response of rice, with 83 % of the differentially expressed genes being classified as combination-specific. Whatever the combination, most of the differentially expressed genes are involved in primary metabolism, transport, regulation of transcription and protein fate. When considering genes involved in response to stress and plant defence, it appears that strain B510, a strain displaying endophytic properties, leads to the repression of a wider set of genes than strain 4B. Individual genotypic variations could be the most important driving force of rice roots gene expression upon Azospirillum inoculation. Strain-dependent transcriptional changes observed for genes related to auxin and ethylene signalling highlight the complexity of hormone signalling networks in the Azospirillum

  14. Vescicular-arbuscular mycorrhiza and Azospirillum brasilense rhizocoenosis in pearlmillet in a semi-arid soil

    International Nuclear Information System (INIS)

    Tilak, K.V.B.R.; Sachdev, M.S.; Sachdev, Pamila

    2007-01-01

    A field experiment was conducted in an alluvial sandy loam soil using Pearlmillet as the test crop to study the effect of Vescicular-Arbuscular Mycorrhiza (VAM) and Azospirillum with phosphorus on yield and other parameters. Dual inoculation gave a significant increase in Azospirillum and VAM infection in root over the control plants, and resulted in significant increase in grain yield. Combined inoculation alongwith N and P application showed maximum P uptake. Nitrogen fixation increased with plant growth with dually inoculated N and P treatment, The effect was more pronounced in the presence of phosphrous indicating that P is required for nitrogen fixation. (author)

  15. Carotenoid production and phenotypic variation in Azospirillum brasilense.

    Science.gov (United States)

    Brenholtz, Gal Reem; Tamir-Ariel, Dafna; Okon, Yaacov; Burdman, Saul

    2017-06-01

    We assessed the occurrence of phenotypic variation in Azospirillum brasilense strains Sp7, Cd, Sp245, Az39 and phv2 during growth in rich media, screening for variants altered in colony pigmentation or extracellular polysaccharide (EPS) production. Previous studies showed that EPS-overproducing variants of Sp7 appear frequently following starvation or growth in minimal medium. In contrast, no such variants were detected during growth in rich media in the tested strains except for few variants of phv2. Regarding alteration in colony pigmentation (from pink to white in strain Cd and from white to pink in the others), strain Sp7 showed a relatively high frequency of variation (0.009-0.026%). Strain Cd showed a lower frequency of alteration in pigmentation (0-0.008%), and this type of variation was not detected in the other strains. In A. brasilense, carotenoid synthesis is controlled by two RpoE sigma factors and their cognate ChrR anti-sigma factors, the latter acting as negative regulators of carotenoid synthesis. Here, all tested (n = 28) pink variants of Sp7 carried mutations in one of the anti-sigma factor genes, chrR1. Our findings indicate that, in A. brasilense, phenotypic variation is strain- and environment-dependent and support the central role of ChrR1 in regulation of carotenoid production. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  16. Energy Taxis Is the Dominant Behavior in Azospirillum brasilense

    Science.gov (United States)

    Alexandre, Gladys; Greer, Suzanne E.; Zhulin, Igor B.

    2000-01-01

    Energy taxis encompasses aerotaxis, phototaxis, redox taxis, taxis to alternative electron acceptors, and chemotaxis to oxidizable substrates. The signal for this type of behavior is originated within the electron transport system. Energy taxis was demonstrated, as a part of an overall behavior, in several microbial species, but it did not appear as the dominant determinant in any of them. In this study, we show that most behavioral responses proceed through this mechanism in the alpha-proteobacterium Azospirillum brasilense. First, chemotaxis to most chemoeffectors typical of the azospirilla habitat was found to be metabolism dependent and required a functional electron transport system. Second, other energy-related responses, such as aerotaxis, redox taxis, and taxis to alternative electron acceptors, were found in A. brasilense. Finally, a mutant lacking a cytochrome c oxidase of the cbb3 type was affected in chemotaxis, redox taxis, and aerotaxis. Altogether, the results indicate that behavioral responses to most stimuli in A. brasilense are triggered by changes in the electron transport system. PMID:11029423

  17. Beneficial reuse '97

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    The annual Beneficial Reuse Conference was conducted in Knoxville, Tennessee from August 5-7, 1997. Now in its fifth year, this conference has become the national forum for discussing the beneficial reuse and recycle of contaminated buildings, equipment and resources, and the fabrication of useful products from such resources. As in the past, the primary goal of Beneficial Reuse ''97 was to provide a forum for the practitioners of pollution prevention, decontamination and decommissioning, waste minimization, reindustrialization, asset management, privatization and recycling to share their successes and failures, as well as their innovative strategies and operational experiences with the assembled group of stakeholders. Separate abstracts have been indexed into the database for contributions to this conference proceedings

  18. Results in the application of biofertilizers using Azospirillum and Mycorrhiza, in associations of horticultural crops under semi-greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Dania Bárbara Núñez Sosa

    2013-01-01

    Full Text Available The current research was carried out in the greenhouse “La Condesa”, which belongs to the Empresa de Cultivos Varios “Lenin”, in Jovellanos, Matanzas province. Its main objective was to evaluate the effect of the application of biofertilizer (Azospirillum sp and Micorrizas in combinations of crops (lettuce and radish, or beet and radish. The research included four different treatments: witness, Micorrizas, Azospirillum, Azospirillum +Micorrizas. We used an at random block design. Data were processed after evaluating yields components by using the statistical software called Statgraphics, version 5.0. The research showed a positive response to the application of biofertilizers, resulting in a considerable increase of profits.

  19. FTIR spectroscopic study of biofilms formed by the rhizobacterium Azospirillum brasilense Sp245 and its mutant Azospirillum brasilense Sp245.1610

    Science.gov (United States)

    Tugarova, Anna V.; Scheludko, Andrei V.; Dyatlova, Yulia A.; Filip'echeva, Yulia A.; Kamnev, Alexander A.

    2017-07-01

    Biofilms are spatially and metabolically structured communities of microorganisms, representing a mode of their existence which is ubiquitous in nature, with cells localised within an extracellular biopolymeric matrix, attached to each other, at an interface. For plant-growth-promoting rhizobacteria (PGPR), the formation of biofilms is of special importance due to their primary localisation at the surface of plant root systems. In this work, FTIR spectroscopy was used, for the first time for bacteria of the genus Azospirillum, to comparatively study 6-day-mature biofilms formed on the surface of ZnSe discs by the rhizobacterium Azospirillum brasilense Sp245 and its mutant A. brasilense Sp245.1610. The mutant strain, having an Omegon Km insertion in the gene of lipid metabolism fabG1 on the plasmid AZOBR_p1, as compared to the wild-type strain Sp245 (see http://dx.doi.org/10.1134/S1022795413110112)

  20. Revealing strategies of quorum sensing in Azospirillum brasilense strains Ab-V5 and Ab-V6.

    Science.gov (United States)

    Fukami, Josiane; Abrantes, Julia Laura Fernandes; Del Cerro, Pablo; Nogueira, Marco Antonio; Ollero, Francisco Javier; Megías, Manuel; Hungria, Mariangela

    2018-01-01

    Azospirillum brasilense is an important plant-growth promoting bacterium (PGPB) that requires several critical steps for root colonization, including biofilm and exopolysaccharide (EPS) synthesis and cell motility. In several bacteria these mechanisms are mediated by quorum sensing (QS) systems that regulate the expression of specific genes mediated by the autoinducers N-acyl-homoserine lactones (AHLs). We investigated QS mechanisms in strains Ab-V5 and Ab-V6 of A. brasilense, which are broadly used in commercial inoculants in Brazil. Neither of these strains carries a luxI gene, but there are several luxR solos that might perceive AHL molecules. By adding external AHLs we verified that biofilm and EPS production and cell motility (swimming and swarming) were regulated via QS in Ab-V5, but not in Ab-V6. Differences were observed not only between strains, but also in the specificity of LuxR-type receptors to AHL molecules. However, Ab-V6 was outstanding in indole acetic acid (IAA) synthesis and this molecule might mimic AHL signals. We also applied the quorum quenching (QQ) strategy, obtaining transconjugants of Ab-V5 and Ab-V6 carrying a plasmid with acyl-homoserine lactonase. When maize (Zea mays L.) was inoculated with the wild-type and transconjugant strains, plant growth was decreased with the transconjugant of Ab-V5-confirming the importance of an AHL-mediated QS system-but did not affect plant growth promotion by Ab-V6.

  1. Influence of Azospirillum spp. on the nitrogen supply of a gramineous host

    NARCIS (Netherlands)

    Christiansen - Weniger, C.

    1991-01-01

    The main objectives of this study were to identify factors that control the behaviour of Azospirillum in the rhizosphere of a gramineous plant in order to be able to optimize the association between the bacteria and the host plants in terms of nitrogen supply to the

  2. Maize growth in response to Azospirillum brasilense, Rhizobium tropici, molybdenum and nitrogen

    Directory of Open Access Journals (Sweden)

    Angelita A. C. Picazevicz

    Full Text Available ABSTRACT The objective of this research was to evaluate the effect of Azospirillum brasilense, Rhizobium tropici, nitrogen (N and molybdenum (Mo fertilization on maize growth. The experiment was carried out in a greenhouse from October to November 2015, in a completely randomized design, in 2 x 2 x 2 x 5 factorial scheme, with 5 replicates, corresponding to the absence and presence of Azospirillum brasilense, Rhizobium tropici, N (30 kg ha-1 and five Mo doses (0, 7.5, 15.0, 22.5 and 30.0 g ha-1. The analyzed variables were: plant height, basal stem diameter, dry biomass of shoots, roots, total and N accumulated in the shoots. There was double or triple interaction between N fertilization, Azospirillum brasilense and Rhizobium tropici for the evaluated variables. However, isolated and/or combined effect of Mo was not observed. Seed inoculation with Azospirillum brasilense as well as their co-inoculation with Rhizobium tropici in the absence of N fertilization was efficient to increase plant growth. Soil N fertilization at sowing was less efficient in promoting plant growth than when it was combined with seed inoculation with Rhizobium tropici.

  3. Beneficial bread without preservatives

    OpenAIRE

    Denkova, Zapryana; Denkova, Rositsa

    2014-01-01

    Besides their inherent nutritional value functional foods contain substances that have beneficial impact on the functioning of organs and systems in the human body and reduce the risk of disease. Bread and bakery goods are basic foods in the diet of contemporary people. Preservatives are added to the composition of foods in order to ensure their microbiological safety, but these substances affect directly the balance of microflora in the tract. A great problem is mold and bacterial spoilage (...

  4. Study of Beneficial Levels and Effect of Azotobacter spp. and Azospirillium spp.

    Directory of Open Access Journals (Sweden)

    A Ostadi Jaafari

    2012-10-01

    Full Text Available In order to evaluate the effects of beneficial free living bacteria (Azotobacter chroococcum and Azospirillum brasilense compared to different nitrogen fertilizer levels on yield and yield components of barley (Hordeum vulgare cv Reyhan a field experiment was conducted at Research Station College of Agriculture, Ferdowsi University of Mashhad in 2007-2008. The experiment was arranged in a randomized complete block design with three replications. Fertilizer treatments were biological fertilizer (combine of Azotobacter and Azospirillum and six nitrogen fertilizer levels (0, 20, 40, 60, 80 and 100 kg/ha. The plant characteristics were studied in terms of leaf area index, crop growth rate, total dry weight, shoot and root dry matter per plant and seed yield. The results showed that the effect of different nitrogen fertilizer levels imposed a significant effect on all plant characteristics. The difference between biological fertilizers, 60 and 80kg nitrogen fertilizer levels in shoot dry weight were not significant. Additionally, in root dry weight and root/shoot ratio there were significant difference between biological fertilizer and all nitrogen fertilizer levels. There was no significant difference between biological fertilizer, 80 and 100 kg nitrogen fertilizer levels in terms of seed yield. There was no significant difference among biological fertilizer, 40, 60 and 80kg nitrogen fertilizer levels in leaf area index at three finally samples. It seems that, in this experiment biological fertilizer could be provide plant nitrogen requirements the same as 40-80kg nitrogen per hectare.

  5. Carotenoid Biosynthetic Pathways Are Regulated by a Network of Multiple Cascades of Alternative Sigma Factors in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Rai, Ashutosh Kumar; Dubey, Ashutosh Prakash; Kumar, Santosh; Dutta, Debashis; Mishra, Mukti Nath; Singh, Bhupendra Narain; Tripathi, Anil Kumar

    2016-11-01

    Carotenoids constitute an important component of the defense system against photooxidative stress in bacteria. In Azospirillum brasilense Sp7, a nonphotosynthetic rhizobacterium, carotenoid synthesis is controlled by a pair of extracytoplasmic function sigma factors (RpoEs) and their cognate zinc-binding anti-sigma factors (ChrRs). Its genome harbors two copies of the gene encoding geranylgeranyl pyrophosphate synthase (CrtE), the first critical step in the carotenoid biosynthetic pathway in bacteria. Inactivation of each of two crtE paralogs found in A. brasilense caused reduction in carotenoid content, suggesting their involvement in carotenoid synthesis. However, the effect of crtE1 deletion was more pronounced than that of crtE2 deletion. Out of the five paralogs of rpoH in A. brasilense, overexpression of rpoH1 and rpoH2 enhanced carotenoid synthesis. Promoters of crtE2 and rpoH2 were found to be dependent on RpoH2 and RpoE1, respectively. Using a two-plasmid system in Escherichia coli, we have shown that the crtE2 gene of A. brasilense Sp7 is regulated by two cascades of sigma factors: one consisting of RpoE1and RpoH2 and the other consisting of RpoE2 and RpoH1. In addition, expression of crtE1 was upregulated indirectly by RpoE1 and RpoE2. This study shows, for the first time in any carotenoid-producing bacterium, that the regulation of carotenoid biosynthetic pathway involves a network of multiple cascades of alternative sigma factors. Carotenoids play a very important role in coping with photooxidative stress in prokaryotes and eukaryotes. Although extracytoplasmic function (ECF) sigma factors are known to directly regulate the expression of carotenoid biosynthetic genes in bacteria, regulation of carotenoid biosynthesis by one or multiple cascades of sigma factors had not been reported. This study provides the first evidence of the involvement of multiple cascades of sigma factors in the regulation of carotenoid synthesis in any bacterium by showing the

  6. Beneficial use of isotopes

    International Nuclear Information System (INIS)

    Bertel, E.; Stevens, G.H.

    1998-01-01

    The paper gives an outlook on the main isotopes currently used for beneficial applications, provides an overview on geographic distribution of isotope production capabilities and identifies the main suppliers world-wide. It analyses trends in different countries and regions, including the refurbishment and/or replacement of ageing facilities and the implementation of new capabilities. Issues related to adequate supply of isotopes and potential under or over capacity of production for some key products are discussed. The evolution of the isotope production sector is analysed. Issues such as lowering of governmental support to production facilities, emergence of international co-operation and agreements on production capabilities, and developments in non-OECD/NEA countries are addressed. The paper offers some concluding remarks on the importance of maintaining and enhancing beneficial uses of isotopes, the role of government policies, the need for co-operation between countries and between the private and public sectors. The paper addresses the role of international cooperation in making efficient use of existing isotope production capacity and investigates ways for reducing the need for investment in additional capacity. (author)

  7. Accumulation of intra-cellular polyphosphate in Chlorella vulgaris cells is related to indole-3-acetic acid produced by Azospirillum brasilense.

    Science.gov (United States)

    Meza, Beatriz; de-Bashan, Luz E; Hernandez, Juan-Pablo; Bashan, Yoav

    2015-06-01

    Accumulation of intra-cellular phosphate, as polyphosphate, was measured when the microalga Chlorella vulgaris was immobilized in alginate with either of two wild-type strains of the microalgae growth-promoting bacterium Azospirillum brasilense or their corresponding IAA-attenuated mutants. Wild type strains of A. brasilense induced higher amounts of intra-cellular phosphate in Chlorella than their respective mutants. Calculations comparing intra-cellular phosphate accumulation by culture or net accumulation by the cell and the amount of IAA that was produced by each of these strains revealed that higher IAA was linked to higher accumulations of intra-cellular phosphate. Application of four levels of exogenous IAA reported for A. brasilense and their IAA-attenuated mutants to cultures of C. vulgaris enhanced accumulation of intra-cellular phosphate; the higher the content of IAA per culture or per single cell, the higher was the amount of accumulated phosphate. When an IAA-attenuated mutant was complemented with exogenous IAA, accumulation of intra-cellular phosphate at the culture level was even higher than phosphate accumulation with the respective wild type strains. When calculating the net accumulation of intra-cellular phosphate in the complementation experiment, net intra-cellular phosphate induced by the IAA-attenuated mutant was completely restored and was similar to the wild strains. We propose that IAA produced by A. brasilense is linked to polyphosphate accumulation in C. vulgaris. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  8. 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.

  9. A SAM-dependent methyltransferase cotranscribed with arsenate reductase alters resistance to peptidyl transferase center-binding antibiotics in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Singh, Sudhir; Singh, Chhaya; Tripathi, Anil Kumar

    2014-05-01

    The genome of Azospirillum brasilense harbors a gene encoding S-adenosylmethionine-dependent methyltransferase, which is located downstream of an arsenate reductase gene. Both genes are cotranscribed and translationally coupled. When they were cloned and expressed individually in an arsenate-sensitive strain of Escherichia coli, arsenate reductase conferred tolerance to arsenate; however, methyltransferase failed to do so. Sequence analysis revealed that methyltransferase was more closely related to a PrmB-type N5-glutamine methyltransferase than to the arsenate detoxifying methyltransferase ArsM. Insertional inactivation of prmB gene in A. brasilense resulted in an increased sensitivity to chloramphenicol and resistance to tiamulin and clindamycin, which are known to bind at the peptidyl transferase center (PTC) in the ribosome. These observations suggested that the inability of prmB:km mutant to methylate L3 protein might alter hydrophobicity in the antibiotic-binding pocket of the PTC, which might affect the binding of chloramphenicol, clindamycin, and tiamulin differentially. This is the first report showing the role of PrmB-type N5-glutamine methyltransferases in conferring resistance to tiamulin and clindamycin in any bacterium.

  10. RpoH2 sigma factor controls the photooxidative stress response in a non-photosynthetic rhizobacterium, Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kumar, Santosh; Rai, Ashutosh Kumar; Mishra, Mukti Nath; Shukla, Mansi; Singh, Pradhyumna Kumar; Tripathi, Anil Kumar

    2012-12-01

    Bacteria belonging to the Alphaproteobacteria normally harbour multiple copies of the heat shock sigma factor (known as σ(32), σ(H) or RpoH). Azospirillum brasilense, a non-photosynthetic rhizobacterium, harbours five copies of rpoH genes, one of which is an rpoH2 homologue. The genes around the rpoH2 locus in A. brasilense show synteny with that found in rhizobia. The rpoH2 of A. brasilense was able to complement the temperature-sensitive phenotype of the Escherichia coli rpoH mutant. Inactivation of rpoH2 in A. brasilense results in increased sensitivity to methylene blue and to triphenyl tetrazolium chloride (TTC). Exposure of A. brasilense to TTC and the singlet oxygen-generating agent methylene blue induced several-fold higher expression of rpoH2. Comparison of the proteome of A. brasilense with its rpoH2 deletion mutant and with an A. brasilense strain overexpressing rpoH2 revealed chaperone GroEL, elongation factors (Ef-Tu and EF-G), peptidyl prolyl isomerase, and peptide methionine sulfoxide reductase as the major proteins whose expression was controlled by RpoH2. Here, we show that the RpoH2 sigma factor-controlled photooxidative stress response in A. brasilense is similar to that in the photosynthetic bacterium Rhodobacter sphaeroides, but that RpoH2 is not involved in the detoxification of methylglyoxal in A. brasilense.

  11. In Azospirillum brasilense, mutations in flmA or flmB genes affect polar flagellum assembly, surface polysaccharides, and attachment to maize roots.

    Science.gov (United States)

    Rossi, Fernando Ariel; Medeot, Daniela Beatriz; Liaudat, Juan Pablo; Pistorio, Mariano; Jofré, Edgardo

    2016-09-01

    Azospirillum brasilense is a soil bacterium capable of promoting plant growth. Several surface components were previously reported to be involved in the attachment of A. brasilense to root plants. Among these components are the exopolysaccharide (EPS), lipopolysaccharide (LPS) and the polar flagellum. Flagellin from polar flagellum is glycosylated and it was suggested that genes involved in such a posttranslational modification are the same ones involved in the biosynthesis of sugars present in the O-antigen of the LPS. In this work, we report on the characterization of two homologs present in A. brasilense Cd, to the well characterized flagellin modification genes, flmA and flmB, from Aeromonas caviae. We show that mutations in either flmA or flmB genes of A. brasilense resulted in non-motile cells due to alterations in the polar flagellum assembly. Moreover, these mutations also affected the capability of A. brasilense cells to adsorb to maize roots and to produce LPS and EPS. By generating a mutant containing the polar flagellum affected in their rotation, we show the importance of the bacterial motility for the early colonization of maize roots. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. Growth of Quailbush in Acidic, Metalliferous Desert Mine Tailings: Effect of Azospirillum brasilense Sp6 on Biomass Production and Rhizosphere Community Structure

    Science.gov (United States)

    de-Bashan, Luz E.; Hernandez, Juan-Pablo; Nelson, Karis N.; Bashan, Yoav

    2010-01-01

    Mine tailing deposits in semiarid and arid environments frequently remain devoid of vegetation due to the toxicity of the substrate and the absence of a diverse soil microbial community capable of supporting seed germination and plant growth. The contribution of the plant growth promoting bacterium (PGPB) Azospirillum brasilense Sp6 to the growth of quailbush in compost-amended, moderately acidic, high-metal content mine tailings using an irrigation-based reclamation strategy was examined along with its influence on the rhizosphere bacterial community. Sp6 inoculation resulted in a significant (2.2-fold) increase in plant biomass production. The data suggest that the inoculum successfully colonized the root surface and persisted throughout the 60-day experiment in both the rhizosphere, as demonstrated by excision and sequencing of the appropriate denaturing gradient gel electrophoresis (DGGE) band, and the rhizoplane, as indicated by fluorescent in situ hybridization of root surfaces. Changes in rhizosphere community structure in response to Sp6 inoculation were evaluated after 15, 30, and 60 days using DGGE analysis of 16S rRNA polymerase chain reaction amplicons. A comparison of DGGE profiles using canonical correspondence analysis revealed a significant treatment effect (Sp6-inoculated vs. uninoculated plants vs. unplanted) on bacterial community structure at 15, 30, and 60 days (p<0.05). These data indicate that in an extremely stressed environment such as acid mine tailings, an inoculated plant growth promoting bacterium not only can persist and stimulate plant growth but also can directly or indirectly influence rhizobacterial community development. PMID:20632001

  13. [Identification of Azospirillum genus bacteria isolated from the spring wheat root zone].

    Science.gov (United States)

    Kopylov, Ie P; Spyrydonov, V H; Patyka, V P

    2009-01-01

    Bacteria with high N2-fixing activity were isolated from the root zone of spring wheat grown on leach chernozem and soddy podzolic soil in Ukrainian marshy woodlands. They were characterized by phenotypic signs and investigated with the help of molecular-genetic methods. On the basis of diagnostic signs the investigated strains were referred to Azospirillum brasilense from Azospirillum genus. Their 3'- and 5'-thermal 16S RNA hypervariable sites with length from 373 to 395 nucleotides were amplified and sequenced. The comparative analysis of results confirmed the 100% identity of 16S RNA sequences from investigated bacteria with the same sequences of A. brasilense from Gene Bank database. Thus the results of sequence analysis agree with results obtained during the investigation of phenotypic signs.

  14. Azospirillum Inoculation Alters Nitrate Reductase Activity and Nitrogen Uptake in Wheat Plant Under Water Deficit Conditions

    OpenAIRE

    N. Aliasgharzad, N. Aliasgharzad; Heydaryan, Zahra; Sarikhani, M.R

    2014-01-01

    Water deficit stress usually diminishes nitrogen uptake by plants. There are evidences that some nitrogen fixing bacteria can alleviate this stress by supplying nitrogen and improving its metabolism in plants. Four Azospirillum strains, A. lipoferum AC45-II, A. brasilense AC46-I, A. irakense AC49-VII and A. irakense AC51-VI were tested for nitrate reductase activity (NRA). In a pot culture experiment using a sandy loam soil, wheat plants (Triticum aestivum L. cv. Sardari) were inoculated with...

  15. Beneficial uses of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fox, M.R.

    1991-10-01

    An overall decline in technical literacy within the American public has come at a time when technological advances are accelerating in the United States and around the world. This had led to a large communication gulf between the general public and the technologists. Nowhere is this more evident then with the topic of radiation. Regrettably, too few people know about sources of radiation, the pervasiveness, amounts, and variabilities, and do not have a true understanding of the environment in which we live. Nor do many people know that radiation has been used in beneficial ways for decades around the world. While the general public does not know of the scientific applications to which radiation has been deployed, it nevertheless had benefited tremendously from these efforts. Thanks to the well know properties of radiation, scientific ingenuity has found many uses of radiation in chemical and agricultural research, biomedical research, in the diagnoses and treatment of hundreds of types of diseases, in industrial applications, food irradiation, and many others. This paper provides a sample of the types of uses to which radiation has been used to help advance the betterment of humankind.

  16. Beneficiation of lunar ilmenite

    Science.gov (United States)

    Ruiz, Joaquin

    1991-01-01

    One of the most important commodities lacking in the moon is free oxygen which is required for life and used extensively for propellent. Free oxygen, however, can be obtained by liberating it from the oxides and silicates that form the lunar rocks and regolith. Ilmenite (FeTiO3) is considered one of the leading candidates for production of oxygen because it can be reduced with a reasonable amount of energy and it is an abundant mineral in the lunar regolith and many mare basalts. In order to obtain oxygen from ilmenite, a method must be developed to beneficiate ilmenite from lunar material. Two possible techniques are electrostatic or magnetic methods. Both methods have complications because lunar ilmenite completely lacks Fe(3+). Magnetic methods were tested on eucrite meteorites, which are a good chemical simulant for low Ti mare basalts. The ilmenite yields in the experiments were always very low and the eucrite had to be crushed to xxxx. These data suggest that magnetic separation of ilmenite from fine grain lunar basalts would not be cost effective. Presently, experiments are being performed with electrostatic separators, and lunar regolith is being waited for so that simulants do not have to be employed.

  17. Beneficial uses of radiation

    International Nuclear Information System (INIS)

    Fox, M.R.

    1991-10-01

    An overall decline in technical literacy within the American public has come at a time when technological advances are accelerating in the United States and around the world. This had led to a large communication gulf between the general public and the technologists. Nowhere is this more evident then with the topic of radiation. Regrettably, too few people know about sources of radiation, the pervasiveness, amounts, and variabilities, and do not have a true understanding of the environment in which we live. Nor do many people know that radiation has been used in beneficial ways for decades around the world. While the general public does not know of the scientific applications to which radiation has been deployed, it nevertheless had benefited tremendously from these efforts. Thanks to the well know properties of radiation, scientific ingenuity has found many uses of radiation in chemical and agricultural research, biomedical research, in the diagnoses and treatment of hundreds of types of diseases, in industrial applications, food irradiation, and many others. This paper provides a sample of the types of uses to which radiation has been used to help advance the betterment of humankind

  18. Beneficial Properties of Probiotics

    Science.gov (United States)

    Shi, Lye Huey; Balakrishnan, Kunasundari; Thiagarajah, Kokila; Mohd Ismail, Nor Ismaliza; Yin, Ooi Shao

    2016-01-01

    Probiotics are live microorganisms that can be found in fermented foods and cultured milk, and are widely used for the preparation of infant food. They are well-known as “health friendly bacteria”, which exhibit various health beneficial properties such as prevention of bowel diseases, improving the immune system, for lactose intolerance and intestinal microbial balance, exhibiting antihypercholesterolemic and antihypertensive effects, alleviation of postmenopausal disorders, and reducing traveller’s diarrhoea. Recent studies have also been focused on their uses in treating skin and oral diseases. In addition to that, modulation of the gut-brain by probiotics has been suggested as a novel therapeutic solution for anxiety and depression. Thus, this review discusses on the current probiotics-based products in Malaysia, criteria for selection of probiotics, and evidences obtained from past studies on how probiotics have been used in preventing intestinal disorders via improving the immune system, acting as an antihypercholesterolemic factor, improving oral and dermal health, and performing as anti-anxiety and anti-depressive agents. PMID:27688852

  19. Characterization and effect of Azotobacter, Azospirillum and Pseudomonas associated with Ipomoea Batatas of Colombian Caribbean

    Directory of Open Access Journals (Sweden)

    Jazmín Vanessa Pérez-Pazos

    2017-07-01

    Full Text Available The use of plant growth promoting Rhizobacteria (PGPR is an alternative to replace chemical fertilizers for the cultivation of agricultural crops. The aim of this research was to search, selection and characterization of PGPR from the genus Azotobacter, Azospirillum and Pseudomonas natives from sweet potato (Ipomoea batatas plants and rhizosphere of representative production regions of the Colombian Caribbean. Selected isolates were identified by molecular methods and they were screened in vitro for activities related to plant growth such as phosphate solubilization, indole production and acetylene reduction. The strains were tested in the greenhouse on plants of Ipomoea batatas produced in vitro. The height, root length, dry mass of the shot and root were evaluated. Associated with sweet potato crop us finded strains identificated as Azotobacter vinelandii, Azotobacter chroococcum, Azospirillum lipoferum, Azospirillum brasilense and Pseudomonas denitrificans. The strains were able to solubilize phosphate, synthesize indole-3-acetic acid (IAA and reduce acetylene. The inoculation of bacteria selected increased growth parameters such as root length, height, dry weight root and shoot in plants of sweet potato in greenhouse. Those results catalog to the isolated obtained as possible microorganisms with potential as biofertilizers in sweet potato.

  20. Seed inoculation with Azospirillum brasilense and N fertilization of corn in the Cerrado biome

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pereira de Vasconcelos

    Full Text Available ABSTRACT There is a great interest to reduce doses and increase efficiency of inputs in agriculture. One alternative to lower doses of N fertilizers in corn is seed inoculation with diazotrophic bacteria, which can fix atmospheric N in soil. This study aimed to evaluate the effect of N doses-in the absence and presence of Azospirillum brasilense-on plant nutritional status at different growth stages and on seed yield of corn. The experiment was conducted during the 2011/2012 production season on a typical cerrado soil in Uberlândia, Triângulo Mineiro. The experimental design was randomized blocks with six repetitions. The treatments consisted of five N doses and the absence or presence of Azospirillum brasilense (100 mL ha-1 as a seed inoculant. A commercial product with minimum concentration of 2x108 CFU mL-1 100 mL ha-1 was used. Inoculation with Azospirillum brasilense did not significantly affect corn macronutrient content and yield, except for foliar calcium and potassium at 200 kg N ha-1 at the V8 stage. Corn yield increased with N doses up to 150 kg N ha-1.

  1. Cellular responses during morphological transformation in Azospirillum brasilense and Its flcA knockout mutant.

    Directory of Open Access Journals (Sweden)

    Xingsheng Hou

    Full Text Available FlcA is a response regulator controlling flocculation and the morphological transformation of Azospirillum cells from vegetative to cyst-like forms. To understand the cellular responses of Azospirillum to conditions that cause morphological transformation, proteins differentially expressed under flocculation conditions in A. brasilense Sp7 and its flcA knockout mutant were investigated. Comparison of 2-DE protein profiles of wild-type (Sp7 and a flcA deletion mutant (Sp7-flcAΔ revealed a total of 33 differentially expressed 2-DE gel spots, with 22 of these spots confidently separated to allow protein identification. Analysis of these spots by liquid chromatography-tandem mass spectrometry (LC-MS/MS and MASCOT database searching identified 48 proteins (≥10% emPAI in each spot. The functional characteristics of these proteins included carbon metabolism (beta-ketothiolase and citrate synthase, nitrogen metabolism (Glutamine synthetase and nitric oxide synthase, stress tolerance (superoxide dismutase, Alkyl hydroperoxidase and ATP-dependent Clp protease proteolytic subunit and morphological transformation (transducer coupling protein. The observed differences between Sp7 wild-type and flcA- strains enhance our understanding of the morphological transformation process and help to explain previous phenotypical observations. This work is a step forward in connecting the Azospirillum phenome and genome.

  2. [Determination of Azospirillum Brasilense Cells With Bacteriophages via Electrooptical Analysis of Microbial Suspensions].

    Science.gov (United States)

    Gulii, O I; Karavayeva, O A; Pavlii, S A; Sokolov, O I; Bunin, V D; Ignatov, O V

    2015-01-01

    The dependence-of changes in the electrooptical properties of Azospirillum brasilense cell suspension Sp7 during interaction with bacteriophage ΦAb-Sp7 on the number and time of interactions was studied. Incubation of cells with bacteriophage significantly changed the electrooptical signal within one minute. The selective effect of bacteriophage ΦAb on 18 strains of bacteria of the genus Azospirillum was studied: A. amazonense Ami4, A. brasilense Sp7, Cd, Sp107, Sp245, Jm6B2, Brl4, KR77, S17, S27, SR55, SR75, A. halopraeferans Au4, A. irakense KBC1, K A3, A. lipoferum Sp59b, SR65 and RG20a. We determined the limit of reliable determination of microbial cells infected with bacteriophage: - 10(4) cells/mL. The presence of foreign cell cultures of E. coli B-878 and E. coli XL-1 did not complicate the detection of A brasilense Sp7 cells with the use of bacteriophage ΦAb-Sp7. The results demonstrated that bacteriophage (ΦAb-Sp7 can be used for the detection of Azospirillum microbial cells via t electrooptical analysis of cell suspensions.

  3. Cellular responses during morphological transformation in Azospirillum brasilense and Its flcA knockout mutant.

    Science.gov (United States)

    Hou, Xingsheng; McMillan, Mary; Coumans, Joëlle V F; Poljak, Anne; Raftery, Mark J; Pereg, Lily

    2014-01-01

    FlcA is a response regulator controlling flocculation and the morphological transformation of Azospirillum cells from vegetative to cyst-like forms. To understand the cellular responses of Azospirillum to conditions that cause morphological transformation, proteins differentially expressed under flocculation conditions in A. brasilense Sp7 and its flcA knockout mutant were investigated. Comparison of 2-DE protein profiles of wild-type (Sp7) and a flcA deletion mutant (Sp7-flcAΔ) revealed a total of 33 differentially expressed 2-DE gel spots, with 22 of these spots confidently separated to allow protein identification. Analysis of these spots by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and MASCOT database searching identified 48 proteins (≥10% emPAI in each spot). The functional characteristics of these proteins included carbon metabolism (beta-ketothiolase and citrate synthase), nitrogen metabolism (Glutamine synthetase and nitric oxide synthase), stress tolerance (superoxide dismutase, Alkyl hydroperoxidase and ATP-dependent Clp protease proteolytic subunit) and morphological transformation (transducer coupling protein). The observed differences between Sp7 wild-type and flcA- strains enhance our understanding of the morphological transformation process and help to explain previous phenotypical observations. This work is a step forward in connecting the Azospirillum phenome and genome.

  4. Biofertilization with Azospirillum brasilense improves in vitro culture of Handroanthus ochraceus, a forestry, ornamental and medicinal plant.

    Science.gov (United States)

    Llorente, Berta E; Alasia, María A; Larraburu, Ezequiel E

    2016-01-25

    Biofertilization with plant growth-promoting rhizobacteria is a potential alternative to plant productivity. Here, in vitro propagation of Handroanthus ochraceus (yellow lapacho), a forest crop with high economic and environmental value, was developed using the Azospirillum brasilense strains Cd and Az39 during rhizogenesis. Epicotiles of in vitro plantlets were multiplied in Woody Plant Medium (WPM). For rooting, elongated shoots were transferred to auxin-free Murashige-Skoog medium with Gamborg's vitamins and WPM, both at half salt concentration (½MSG and ½WPM), and inoculated with Cd or Az39 at the base of each shoot. Anatomical studies were performed using leaves cleared and stained with safranin for optical microscopy and leaves and roots metalized with gold-palladium for scanning electron microscopy (SEM). In ½WPM auxin-free medium, A. brasilense Cd inoculation produced 55% of rooting, increased root fresh and dry weight (45% and 77%, respectively), and led to lower stomata size and density with similar proportion of open and closed stomata. Both strains selectively increased the size or density of glandular trichomes in ½MSG. Moreover, bacteria were detected on the root surface by SEM. In conclusion, the difference in H. ochraceus response to A. brasilense inoculation depends on the strain and the plant culture media. Cd strain enhanced rooting in auxin-free ½WPM and produced plantlets with features similar to those expected in ex vitro plants. This work presents an innovative in vitro approach using beneficial plant-microorganism interaction as an ecologically compatible strategy in plant biotechnology. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Relative efficiency of Azotobacter and Azospirillum on yield and P utilization by wheat (Triticum Aestivum) with various N levels

    International Nuclear Information System (INIS)

    Aishwath, O.P.; Dravid, M.S.; Yadav, B.R.

    2002-01-01

    Efficiency of 32 P labelled single superphosphate along with N levels (0, 60, 80 and 120 kg/ha) and biofertilizers (Azotobacter and Azospirillum) was studied on wheat in Typic ustifluvent (saline phase) soil. Average grain and straw yield, total P uptake, per cent P derived by crop from applied phosphorus and its utilization in grain and straw increased either with Azospirillum or Azotobacter inoculation. However, the magnitude of increase in these attributes was of higher extent in presence of Azotobacter as compared to Azospirillum. The yield, uptake and utilization of P increased with increasing levels of N. Per cent Pdff was higher with all levels of N over control, whereas, it was at par with their successive levels. Interaction effect between levels of nitrogen and biofertilizers were also positive and significant at all levels of N with respect to yield and uptake of P, while per cent Pdff and its utilization by wheat was more pronounced at 60 and 80 kg N ha -1 in the presence of Azotobacter. Azospirillum was more effective at 60 kg of N than the other levels. Generally, Azotobacter performed better than the Azospirillum with respect to all parameters. (author)

  6. Reorganization of Azospirillum brasilense cell membrane is mediated by lipid composition adjustment to maintain optimal fluidity during water deficit.

    Science.gov (United States)

    Cesari, A B; Paulucci, N S; Biasutti, M A; Reguera, Y B; Gallarato, L A; Kilmurray, C; Dardanelli, M S

    2016-01-01

    We study the Azospirillum brasilense tolerance to water deficit and the dynamics of adaptive process at the level of the membrane. Azospirillum brasilense was exposed to polyethylene glycol (PEG) growth and PEG shock. Tolerance, phospholipids and fatty acid (FA) composition and membrane fluidity were determined. Azospirillum brasilense was able to grow in the presence of PEG; however, its viability was reduced. Cells grown with PEG showed membrane fluidity similar to those grown without, the lipid composition was modified, increasing phosphatidylcholine and decreasing phosphatidylethanolamine amounts. The unsaturation FAs degree was reduced. The dynamics of the adaptive response revealed a decrease in fluidity 20 min after the addition of PEG, indicating that the PEG has a fluidizing effect on the hydrophobic region of the cell membrane. Fluidity returned to initial values after 60 min of PEG exposure. Azospirillum brasilense is able to perceive osmotic changes by changing the membrane fluidity. This effect is offset by changes in the composition of membrane phospholipid and FA, contributing to the homeostasis of membrane fluidity under water deficit. This knowledge can be used to develop new Azospirillum brasilense formulations showing an adapted membrane to water deficit. © 2015 The Society for Applied Microbiology.

  7. Changes in Nutrient Content of Root and Grain of Wheat Cultivars Inoculated by Azospirillum and Mycorrhiza

    Directory of Open Access Journals (Sweden)

    M. Jiriaie

    2016-02-01

    Full Text Available Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources that are both economically able to provide the nutritional needs of the crop plants and have no adverse effects on the consumers and the environment. Materials and Methods: With this approach, an experiment was conducted in the research station of Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on randomized complete blocks design with three replications. The treatments including Mycorrhizal fungi in three levels (i.e. no use of strain; use of Glomus intraradices strain; and use of Glomus mosseae strain, bacteria Azospirillum lipoferum in two-levels (i.e. non-inoculated and inoculated and wheat cultivars in three levels (i.e. Chamran; Dena; and Behrang. The measured parameters include the concentration of macronutrients (i.e. nitrogen, phosphorus and potassium and some micronutrients (i.e. zinc, iron and manganese in two part seed and the root of wheat. Results and Discussion: Surveying the elements content in the root and the grain indicated a significant and positive effect of the use the Azospirillum and Mycorrhiza to improve the concentration of the elements in wheat cultivars. However, the simultaneous use of these microorganisms led to an increase of the effects of their application on their assessed traits.Finally the highest concentration of N (2.21 present, P (0.50 present and Fe (33.88 mg.kg-1 were observed in the grain; the highest concentration of K (0.93 present and 0.54 present and Mn (43.11 and 23.63 mg.kg-1 were observed in the grain and root, respectively. Moreover, the highest concentration of Zn in the root (19.70 mg.kg-1 was obtained from inoculation of C.V Dena seeds with

  8. Cellulose decomposition and associated nitrogen fixation by mixed cultures of Cellulomonas gelida and Azospirillum species or Bacillus macerans

    Energy Technology Data Exchange (ETDEWEB)

    Halsall, D.M.; Gibson, A.H.

    1985-10-01

    Mixed cultures of Cellulomonas gelida plus Azospirillum lipoferum or Azospirillum brasilense and C. gelida plus Bacillus macerans were shown to degrade cellulose and straw and to utilize the energy-yielding products to fix atmospheric nitrogen. This cooperative process was followed over 30 days in sand-based cultures in which the breakdown of 20% of the cellulose and 28 to 30% of the straw resulted in the fixation of 12 to 14.6 mg of N per g of cellulose and 17 to 19 mg of N per g of straw consumed. Cellulomonas species have certain advantages over aerobic cellulose-degrading fungi in being able to degrade cellulose at oxygen concentrations as low as 1% O/sub 2/ (vol/vol) which would allow a close association between cellulose-degrading and microaerobic diazotrophic microorganisms. Cultures inoculated with initially different proportions of A. brasilense and C. gelida all reached a stable ratio of approximately 1 Azospirillum/3 Cellulomonas cells.

  9. Structural and functional peculiarities of the lipopolysaccharide of Azospirillum brasilense SR55, isolated from the roots of Triticum durum.

    Science.gov (United States)

    Boyko, Alevtina S; Konnova, Svetlana A; Fedonenko, Yulia P; Zdorovenko, Evelina L; Smol'kina, Olga N; Kachala, Vadim V; Ignatov, Vladimir V

    2011-10-20

    Azospirillum brasilense SR55, isolated from the rhizosphere of Triticum durum, was classified as serogroup II on the basis of serological tests. Such serogroup affiliation is uncharacteristic of wheat-associated Azospirillum species. The lipid A of A. brasilense SR55 lipopolysaccharide contained 3-hydroxytetradecanoic, 3-hydroxyhexadecanoic, hexadecanoic and octadecenoic fatty acids. The structure of the lipopolysaccharide's O polysaccharide was established, with the branched octasaccharide repeating unit being represented by l-rhamnose, l-3-O-Me-rhamnose, d-galactose and d-glucuronic acid. The SR55 lipopolysaccharide induced deformations of wheat root hairs. The lipopolysaccharide was not involved in bacterial cell aggregation, but its use to pretreat wheat roots was conducive to cell adsorption. This study shows that Azospirillum bacteria can utilise their own lipopolysaccharide as a carbon source, which may give them an advantage in competitive natural environments. Copyright © 2011 Elsevier GmbH. All rights reserved.

  10. Technical and economic viability of co-inoculation with Azospirillum brasilense in soybean cultivars in the Cerrado

    Directory of Open Access Journals (Sweden)

    Fernando S. Galindo

    Full Text Available ABSTRACT Biological nitrogen fixation (BNF efficiency can be increased by co-inoculation with bradyrhizobia and Azospirillum brasilense, allowing even greater uptake of water and nutrients, leading to higher yields. Thus, this study aimed to evaluate the technical and economic viability of soybean in the Cerrado, according to the cultivars and co-inoculation with Azospirillum brasilense. The experiment was conducted in Selvíria, MS, in no-tillage system, in Oxisol, arranged in a randomized block design in a 2 x 2 factorial scheme with two cultivars (‘Potência’ and ‘Valiosa’, with and without co-inoculation with Azospirillum brasilense in the seed. Co-inoculation with A. brasilense increases grain yield in the cultivars ‘Potência’ and ‘Valiosa’, being economically viable. However, using the cultivar ‘Potência’ co-inoculated led to the highest profitability.

  11. Exo- and surface proteomes of the probiotic bacterium Lactobacillus acidophilus NCFM

    DEFF Research Database (Denmark)

    Celebioglu, Hasan Ufuk; Svensson, Birte

    2017-01-01

    Lactobacillus acidophilus NCFM is a well-known probiotic bacterium extensively studied for its beneficial health effects. Exoproteome (proteins exported into culture medium) and surface proteome (proteins attached to S-layer) of this probiotic were identified by using 2DE followed by MALDI TOF MS...

  12. Improvement of endophytic Azospirillum colonization by co-inoculation with Cellulomonas Uda ATCC 491

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Mehdipour Moghaddam

    2014-04-01

    Full Text Available Introduction: Most of the plant growth promoting rhizobacteria (PGPR such as Azopirillum if accompanied with strong cellulase producing bacteria such as Cellulomonas, their colonization may be increased and their host plants growth improved. Materials and methods: Six endophytic Azospirilla which isolated from three rice and three wheat cultivars and also one strain from commercial biofertilizer (Green Biotech Co., identified by biochemical tests and 16S rDNA analysis and were studied on the basis of cellulase, pectinase and auxin production and also their chemotaxis toward rice and wheat cultivars exudates was investigated. Two cellulase positive (A5 and A6 and two negative (A2 and A3 strains were selected and their interaction with C. uda ATCC 491 on auxin production and colonization on roots were compared. Results: This study showed that none of the strains had pectinase activity, but the strain isolated from rice had more Carboxy methyl cellulase (CMCase activity. Selected isolates and C. uda ATCC 491 showed chemotaxis toward roots exudates. In most of the isolates, rate of auxin production increased by coculture with C. uda ATCC 491. Also, it was determined that C. uda ATCC 491 promoted the colonization of Azospirillum without or with cellulase activity on rice and wheat roots, respectively. Discussion and conclusion: Co-inoculation Azospirillum with C. uda ATCC 491 improves plant root system due to stimulation or additive effect of auxin production and cellulase activity, followed by more uptakes of water and minerals by roots. Also, it raises the number of colonization niches for useful bacteria such as Azospirillum and finally quantitative and qualitative plant parameters.

  13. Lactococcus lactis - a diploid bacterium

    DEFF Research Database (Denmark)

    Michelsen, Ole; Hansen, Flemming G.; Jensen, Peter Ruhdal

    the next division. Thus, the regions of the chromosome that are the last to be replicated are haploid even in fast-growing bacteria. In contrast to this general rule for bacteria, we found that Lactococcus lactis, a bacterium which has been exploited for thousands of years for the production of fermented...... milk products, is born with two complete non-replicating chromosomes. L. lactis therefore remain diploid throughout its entire life cycle....

  14. [Isolation and purification of Mn-peroxidase from Azospirillum brasilense Sp245].

    Science.gov (United States)

    Kupriashina, M A; Selivanov, N Iu; Nikitina, V E

    2012-01-01

    Homogenous Mn-peroxidase of a 26-fold purity grade was isolated from a culture of Azospirillum brasilense Sp245 cultivated on a medium containing 0.1 mM pyrocatechol. The molecular weight of the enzyme is 43 kD as revealed by electrophoresis in SDS-PAAG. It was shown that the use of pyrocatechol and 2,2'-azino-bis(3-ethylbenzotiazoline-6-sulfonate) at concentrations of 0.1 and I mM as inductors increased the Mn-peroxidase activity by a factor of 3.

  15. Beneficial Use of Dredged Material

    Science.gov (United States)

    An important goal of managing dredged material is to ensure that the material is used or disposed of in an environmentally sound manner.Most of this dredged material could be used in a beneficial manner instead.

  16. The evaluation of IAA-production ability in indigenous Azospirillum isolates and their growth promoting effects on sweet corn

    Directory of Open Access Journals (Sweden)

    mahdi arab

    2009-06-01

    Full Text Available It has been years that Azospirillum is known to promote plant growth. Phytohormone (especially Auxin production has the most important role in increasing the yield of inoculated plants. According to this, 60 strains of this genus were isolated, identified, and purified. This ability was evaluated in both qualitative and quantitative assays using colorimetric method and the effects of superior isolate on sweet corn were measured. Results revealed that the abundance and probability of the bacteria isolation is low and 17%. About 31.2% and 100% of Azospirillum strains were capable of producing IAA in qualitative and quantitative methods respectively. In greenhouse experiment, bacteria treatments had significant effects on corn fresh weight, total dry weight, root dry weight and total nitrogen and phosphorus content of the plant. This was considered to be as the result of more lateral root formation which enhances nutrition uptake. In conclusion, the green house results in respect to in vitro achievements show that fortunately it can be claimed that bacteria of the genus Azospirillum can be used widely for not only strategic gramineous plants like: corn, wheat, barely etc. but also for other useful plants. Key words: Azospirillum, Auxin, qualitative and quantitative methods, sweet corn.

  17. Residual phosphate fertilization and Azospirillum brasilense in the common bean in succession to maize intercropped with Marandu grass

    Directory of Open Access Journals (Sweden)

    Lourdes Dickmann

    Full Text Available ABSTRACT One of the alternatives for achieving sustainable agriculture and a reduction in production costs, especially with phosphate fertilisers, is to inoculate seeds with bacteria of the genus Azospirillum. The aim of this study therefore, was to evaluate residual phosphate fertilisation and Azospirillum brasilense, together with the contribution of straw from maize intercropped with Marandu grass, on leaf nutritional content, yield components and winter bean yield. The experiment was carried out on the Teaching and Research Farm, of the School of Engineering at UNESP, located in Selvíria in the State of Mato Grosso do Sul, in a typic clayey dystrophic Red Latosol. The experimental design was of randomised blocks with four replications in a 5 x 2 factorial scheme. The treatments consisted of beans sown on straw from maize intercropped with Marandu grass on areas that had received five levels of P2O5 in the form of MAP, applied during an initial cultivation of black oats (0, 30, 60, 120 and 240 kg ha-1, both with and without inoculation of the oat and maize which preceded the beans with Azospirillum brasilense. Leaf nutrient content, leaf chlorophyll index (ICF, yield components and bean productivity were all evaluated. Inoculation with Azospirillum brasilense of the black oat and maize seeds improved the nutritional status of the plants, but had a negative effect on grain yield. Fertilisation of the oat crop with phosphorus had a positive residual effect on the beans, with increases in yield components and grain yield.

  18. Penggunaan Azospirillum pada Tanah Masam dengan Aluminium Tinggi Terhadap Produksi dan Serapan Nitrogen Rumput Setaria splendida dan Chloris gayana

    Directory of Open Access Journals (Sweden)

    P.D.M.H. Karti

    2005-04-01

    Full Text Available High content of Al on the soil maybe harmful (toxic for plant. Red and yellow podzolic soil was marginal land that characterized by high Al content. Azospirillum is free living N fixing bacteria that can be associated with grass. This research was conducted to find the best yield of grass planted on the soil inoculated with Azospirillum. The research consisted of some steps; 1 soil sampling 2 laboratory research: bacterial isolation, isolate selection, standardized of population, content of IAA 3 pod experiment. Pod experiment in the glass house was designed in completely randomized design, that consisted of six treatments. The variables observed were dry mass production of shoot and root, nitrogen content of shoot and root, and nitrogen absorption. Four best isolates chosen were; SM Setaria, OBIS/BD, PO2 and PM2. Azospirillum isolates enhanced shoot and root production, nitrogen content and N total absorption of tolerance one (S. splendida. The susceptible (C. gayana, Azospirillum significantly enhanced shoot and root nitrogen content, but did not affect the growth, production and N total absorption. Root growth that was inhibited by Al toxicity, decreased the symbiotic capability of nitrogen fixing bacteria. PM2 isolate showed the best effect on production and quality of S. splendida as well as on C. gayana. This isolate will be used for future research. PM2 produces 6.4 ppm Indole Acetic Acid that promoted root growth.

  19. KARAKTERISASI SIFAT-SIFAT BIOKIMIA EKSTRAK KASAR LIPASE EKSTRASELULER BAKTERI Azospirillum sp.PRD1

    Directory of Open Access Journals (Sweden)

    Santi Nur Handayani

    2011-11-01

    Full Text Available Enzim lipase mempunyai peranan penting dalam katalis berbagai reaksi industri satu diantaranya pembuatan flavor melalui reaksi esterifikasi. Lipase adalah biokatalis yang berperan besar dalam aplikasi bioteknologi, seperti dalam sintesis biopolimer, biodiesel, produksi obat, dan produksi flavor. Peningkatan penggunaan lipase untuk industri mendorong dilakukan penelitian untuk mendapatkan sumber-sumber lipase baru. Sumber lipase yang potensial salah satunya adalah bakteri Azospirillum sp.PRD1 dari isolat lokal Laboratorium Mikrobiologi, Fakultas Biologi Universitas Jenderal Soedirman. Tujuan penelitian adalah untuk mendapatkan ekstrak kasar lipase dan menentukan karakteristik sifat-sifat biokimiawinya. Metode yang digunakan antara lain peremajaan bakteri Azospirillum sp.PRD1, dan produksi inokulum, penentuan waktu produksi optimum dan fase pertumbuhan bakteri, ekstraksi dan produksi ekstrak kasar lipase dan penentuan karakteristik sifat-sifat biokimiawinya. Hasil penelitian diperoleh ekstrak kasar lipase dari inokulum berumur 7 jam dan medium produksi dengan induser minyak zaitun yang diinkubasi selama 3 jam memiliki aktivitas spesifik 7,0547 Unit/mg. Lipase ekstrak kasar optimum pada pH 7, suhu 40 oC dan waktu inkubasi selama 25 menit. Lipase merupakan metaloenzim dengan kofaktor Zn2+ , Mn2+, Hg2+, Ca2+, Co2+ and Mg2+.

  20. Insights into the 1.59-Mbp largest plasmid of Azospirillum brasilense CBG497.

    Science.gov (United States)

    Acosta-Cruz, Erika; Wisniewski-Dyé, Florence; Rouy, Zoé; Barbe, Valérie; Valdés, María; Mavingui, Patrick

    2012-09-01

    The plant growth-promoting proteobacterium Azospirillum brasilense enhances growth of many economically important crops, such as wheat, maize, and rice. The sequencing and annotation of the 1.59-Mbp replicon of A. brasilense CBG497, a strain isolated from a maize rhizosphere grown on an alkaline soil in the northeast of Mexico, revealed a GC content of 68.7 % and the presence of 1,430 potential protein-encoding genes, 1,147 of them classified into clusters of orthologous groups categories, and 16 tRNA genes representing 11 tRNA species. The presence of sixty-two genes representatives of the minimal gene set and chromid core genes suggests its importance in bacterial survival. The phaAB → G operon, reported as involved in the bacterial adaptation to alkaline pH in the presence of K(+), was also found on this replicon and detected in several Azospirillum strains. Phylogenetic analysis suggests that it was laterally acquired. We were not able to show its inference on the adaptation to basic pH, giving a hint about the presence of an alternative system for adaptation to alkaline pH.

  1. Reduction of selenite by Azospirillum brasilense with the formation of selenium nanoparticles.

    Science.gov (United States)

    Tugarova, Anna V; Vetchinkina, Elena P; Loshchinina, Ekaterina A; Burov, Andrei M; Nikitina, Valentina E; Kamnev, Alexander A

    2014-10-01

    The ability to reduce selenite (SeO(3)(2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO(3)(2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO(3)(2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures.

  2. 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.

  3. The ipdC, hisC1 and hisC2 genes involved in indole-3-acetic production used as alternative phylogenetic markers in Azospirillum brasilense.

    Science.gov (United States)

    Jijón-Moreno, Saúl; Marcos-Jiménez, Cynthia; Pedraza, Raúl O; Ramírez-Mata, Alberto; de Salamone, I García; Fernández-Scavino, Ana; Vásquez-Hernández, Claudia A; Soto-Urzúa, Lucia; Baca, Beatriz E

    2015-06-01

    Plant growth-promoting bacteria of the genus Azospirillum are present in the rhizosphere and as endophytes of many crops. In this research we studied 40 Azospirillum strains isolated from different plants and geographic regions. They were first characterized by 16S rDNA restriction analysis, and their phylogenetic position was established by sequencing the genes 16S rDNA, ipdC, hisC1, and hisC2. The latter three genes are involved in the indole-3-pyruvic acid (IPyA) biosynthesis pathway of indole-3-acetic acid (IAA). Furthermore, the suitability of the 16S-23S rDNA intergenic spacer sequence (IGS) for the differentiation of closely related Azospirillum taxa and development of PCR protocols allows for specific detection of strains. The IGS-RFLP analysis enabled intraspecies differentiation, particularly of Azospirillum brasilense and Azospirillum lipoferum strains. Results demonstrated that the ipdC, hisC1, and hisC2 genes are highly conserved in all the assessed A. brasilense isolates, suggesting that these genes can be used as an alternative phylogenetic marker. In addition, IAA production determined by HPLC ranged from 0.17 to 98.2 μg mg(-1) protein. Southern hybridization with the A. brasilense ipdC gene probe did not show, a hybridization signal with A. lipoferum, Azospirillum amazonense, Azospirillum halopreferans and Azospirillum irakense genomic DNA. This suggests that these species produce IAA by other pathways. Because IAA is mainly synthesized via the IPyA pathway in A. brasilense strains, a species that is used worldwide in agriculture, the identification of ipdC, hisC1, and hisC2 genes by PCR may be suitable for selecting exploitable strains.

  4. Ore microscopy applied to beneficiation

    International Nuclear Information System (INIS)

    Hagni, R.D.

    1978-01-01

    Ore microscopy can be an important adjunct to beneficiation, because it can be used not only to predict mill problems of undeveloped ore deposits but to identify the causes for the loss of minerals in the products of operating mines and mills. Mineral distribution among various mill products can be determined by examining polished sections prepared from samples obtained from each step of the beneficiation process. The degree of liberation of each mineral can be quantitatively determined for each mill product by counting locked vs. free particles. For many beneficiation problems, the preparation of a few polished sections of carefully selected mill products can yield useful information, which the mill dressing engineer can effectively use to alleviate those problems

  5. Molecular identification of phosphate solubilizing bacterium ...

    African Journals Online (AJOL)

    A phosphate solubilizing bacterium was isolated from the rhizosphere soil of upland rice and identified by 16S rRNA gene sequencing. The gene sequence showed 99% homology with Alcaligenes faecalis. Based on the gene sequence homology, it was identified as A. faecalis. Interaction effect of this bacterium on growth ...

  6. Crecimiento de Azospirillum brasilense en presencia de disacáridos: sacarosa y lactosa

    OpenAIRE

    Yudyt Díaz-Saez; Manuel Díaz-de los Ríos; Mario Alberto-Casas; Arianna Nuñez-Caraballo; Marlene Martínez-Mora

    2013-01-01

    La obtención de biopolímeros a partir de fermentaciones bacterianas requiere de la selección adecuada de las condiciones del proceso. Se evaluó el crecimiento de la cepa Azospirillum brasilense 8-INICA en medio líquido suplementado con disacáridos. Las mediciones se realizaron a las 23 h de incubación con la determinación de la densidad óptica, la concentración de azúcares reductores y concentración de carbohidratos totales, así como la determinación del pH del sobrenadante. Se confirmó el má...

  7. Preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens and their use for bacterial detection.

    Science.gov (United States)

    Dykman, Lev A; Staroverov, Sergei A; Guliy, Olga I; Ignatov, Oleg V; Fomin, Alexander S; Vidyasheva, Irina V; Karavaeva, Olga A; Bunin, Viktor D; Burygin, Gennady L

    2012-01-01

    This article reports the first preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens by using a combinatorial phage library of sheep antibodies. The prepared phage antibodies were used for the first time for lipopolysaccharide and flagellin detection by dot assay, electro-optical analysis of cell suspensions, and transmission electron microscopy. Interaction of A. brasilense Sp245 with antilipopolysaccharide and antiflagellin phage-displayed miniantibodies caused the magnitude of the electro-optical signal to change considerably. The electro-optical results were in good agreement with the electron microscopic data. This is the first reported possibility of employing phage-displayed miniantibodies in bacterial detection aided by electro-optical analysis of cell suspensions.

  8. [Biofilm Formation by the Nonflagellated flhB1 Mutant of Azospirillum brasilense Sp245].

    Science.gov (United States)

    Shelud'ko, A V; Filip'echeva, Yu A; Shumiliva, E M; Khlebtsov, B N; Burov, A M; Petrova, L P; Katsy, E I

    2015-01-01

    Azospirillum brasilense Sp245 with mixed flagellation are able to form biofilms on various surfaces. A nonflagellated mutant of this strain with inactivated chromosomal copy of the flhB gene (flhB1) was shown to exhibit specific traits at the later stages of biofilm formation on a hydrophilic (glass) surface. Mature biofilms of the flhB1::Omegon-Km mutant Sp245.1063 were considerably thinner than those of the parent strain Sp245. The biofilms of the mutant were more susceptible to the forces of hydrodynamic shear. A. brasilense Sp245 cells in biofilms were not found to possess lateral flagella. Cells with polar flagella were, however, revealed by atomic force microscopy of mature native biofilms of strain Sp245. Preservation of a polar flagellum (probably nonmotile) on the cells of A. brasilense Sp245 may enhance the biofilm stability.

  9. Structure of the polysaccharides from the lipopolysaccharide of Azospirillum brasilense Jm125A2.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2015-10-30

    Two polysaccharides were obtained by mild acid degradation of the lipopolysaccharide of associative nitrogen-fixing bacteria Azospirillum brasilense Jm125A2 isolated from the rhizosphere of a pearl millet. The following structures of the polysaccharides were established by sugar and methylation analyses, Smith degradation, and (1)H and (13)C NMR spectroscopy: [Formula: see text] Structure 1 has been reported earlier for a polysaccharide from A. brasilense S17 (Fedonenko YP, Konnova ON, Zdorovenko EL, Konnova SA, Zatonsky GV, Shaskov AS, Ignatov VV, Knirel YA. Carbohydr Res 2008;343:810-6), whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Plant Cell Protolytic Enzymes Activity under Exposure to Lectins of Endophytic and Epiphytic Azospirillum Strains

    Directory of Open Access Journals (Sweden)

    S.A. Alen’kina

    2016-05-01

    Full Text Available We studied the ability of lectins isolated from the surface of the two strains of nitrogen-fixing soil bacteria of the genus Azospirillum, A. brasilense Sp7 (epiphytic and A. brasilense Sp245 (endophytic, to show have a regulating effect on the activity of pectinolytic enzymes in the roots of wheat seedlings. Research results showed that the lectins under study can cause the induction of the activity of polygalacturonase, pectinesterase, pectatlyase from the plant cell wall, thereby ensuring the bacteria penetration in the plant tissues, as well as the induction of plants responses which, being combined with growth-stimulating effect of bacteria, contributes to the formation of plants stability and productivity.

  11. [Factors inducing transition from growth to dormancy in rhizobacteria Azospirillum brasilense].

    Science.gov (United States)

    Kushneruk, M A; Tugarova, A V; Il'chukova, A V; Slavkina, E A; Starichkova, N I; Bogatyrev, V A; Antoniuk, L P

    2013-01-01

    The factors suppressing division of the cells of the rhizobacterium Azospirillum brasilense and inducing their transition to a dormant state were analyzed. These included the presence of hexylresorcinol or heavy metals (Cu and Co) in the medium, oxygen stress, and transfer of the cells into the physiological saline or phosphate buffer solution. The results were used to develop a protocol for obtaining of uncultured cells of A. brasilense Sp245, a natural symbiont of wheat. The cells lost their ability to grow on synthetic agar medium, but could revert to growth when incubated in freshly prepared liquid medium. Needle-shaped crystals differing from struvite, which has been previously reported for this strain, were found in the dormant culture of A. brasilense Sp245.

  12. INFLUÊNCIA DO THIDIAZURON E DA INOCULAÇÃO COM Azospirillum brasilense NO CRESCIMENTO E PRODUTIVIDADE DO ARROZ DE TERRAS ALTAS / INFLUENCE OF THIDIAZURON AND INOCULATION WITH Azospirillum brasilense IN THE GROWTH AND PRODUCTIVITY OF HIGHLAND RICE

    Directory of Open Access Journals (Sweden)

    L. M. Garé

    2017-12-01

    Full Text Available A inoculação com bactérias do gênero Azospirillum pode contribuir com o fornecimento de nitrogênio (N e com o crescimento das plantas, pois esses microrganismos são também promotores de crescimento. Por outro lado a aplicação nas doses e épocas adequadas do regulador vegetal de efeito citocinínico thidiazuron (TDZ pode vir a beneficiar a produtividade de grãos. Dessa maneira, o objetivo do trabalho foi avaliar o efeito de doses de TDZ sobre a produtividade do arroz, na presença e ausência da inoculação foliar com Azospirillum brasilense. Foi utilizada a cultivar ANa 5015, no delineamento experimental de blocos casualizados em esquema fatorial 4 x 2, sendo quatro doses de TDZ (0,0; 0,5; 1,0 e 1,5g ha-1 aplicadas por ocasião do perfilhamento, 30 DAE, e da aplicação de Azospirillum brasilense (presença ou ausência em dose fixa aos 20 DAE. Verificou-se que a cultivar ANa 5015 não se mostrou responsiva para a inoculação foliar com Azospirillum brasilense na dose de 200 mL ha-1. Para as doses de TDZ aplicadas via foliar, houve uma variação significativa na altura de plantas, cuja dose de 0,41 g ha-1 resultou na altura máxima de 1,11 m. Não houve efeito das doses de TDZ na produtividade, massa de 100 grãos, número de panículas por m², grãos por panícula e massa hectolítrica.

  13. Mutants with Enhanced Nitrogenase Activity in Hydroponic Azospirillum brasilense-Wheat Associations

    Science.gov (United States)

    Pereg Gerk, Lily; Gilchrist, Kate; Kennedy, Ivan R.

    2000-01-01

    The effect of a mutation affecting flocculation, differentiation into cyst-like forms, and root colonization on nitrogenase expression by Azospirillum brasilense is described. The gene flcA of strain Sp7 restored these phenotypes in spontaneous mutants of both strains Sp7 and Sp245. Employing both constitutive pLA-lacZ and nifH-lacZ reporter fusions expressed in situ, the colony morphology, colonization pattern, and potential for nitrogenase activity of spontaneous mutants and flcA Tn5-induced mutants were established. The results of this study show that the ability of Sp7 and Sp245 mutant strains to remain in a vegetative form improved their ability to express nitrogenase activity in association with wheat in a hydroponic system. Restoring the cyst formation and colonization pattern to the spontaneous mutant Sp7-S reduced nitrogenase activity rates in association with plants to that of the wild-type Sp7. Although Tn5-induced flcA mutants showed higher potentials for nitrogenase expression than Sp7, their potentials were lower than that of Sp7-S, indicating that other factors in this strain contribute to its exceptional nitrogenase activity rates on plants. The lack of lateral flagella is not one of these factors, as Sp7-PM23, a spontaneous mutant impaired in swarming and lateral-flagellum production but not in flocculation, showed wild-type nitrogenase activity and expression. The results also suggest factors of importance in evolving an effective symbiosis between Azospirillum and wheat, such as increasing the availability of microaerobic niches along the root, increased supply of carbon sources by the plant, and the retention of the bacterial cells in vegetative form for faster metabolism. PMID:10788397

  14. 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.

  15. Next-Generation Beneficial Microbes: The Case of Akkermansia muciniphila

    Directory of Open Access Journals (Sweden)

    Patrice D. Cani

    2017-09-01

    Full Text Available Metabolic disorders associated with obesity and cardiometabolic disorders are worldwide epidemic. Among the different environmental factors, the gut microbiota is now considered as a key player interfering with energy metabolism and host susceptibility to several non-communicable diseases. Among the next-generation beneficial microbes that have been identified, Akkermansia muciniphila is a promising candidate. Indeed, A. muciniphila is inversely associated with obesity, diabetes, cardiometabolic diseases and low-grade inflammation. Besides the numerous correlations observed, a large body of evidence has demonstrated the causal beneficial impact of this bacterium in a variety of preclinical models. Translating these exciting observations to human would be the next logic step and it now appears that several obstacles that would prevent the use of A. muciniphila administration in humans have been overcome. Moreover, several lines of evidence indicate that pasteurization of A. muciniphila not only increases its stability but more importantly increases its efficacy. This strongly positions A. muciniphila in the forefront of next-generation candidates for developing novel food or pharma supplements with beneficial effects. Finally, a specific protein present on the outer membrane of A. muciniphila, termed Amuc_1100, could be strong candidate for future drug development. In conclusion, as plants and its related knowledge, known as pharmacognosy, have been the source for designing drugs over the last century, we propose that microbes and microbiomegnosy, or knowledge of our gut microbiome, can become a novel source of future therapies.

  16. Antioxidants keep the potentially probiotic but highly oxygen-sensitive human gut bacterium Faecalibacterium prausnitzii alive at ambient air

    NARCIS (Netherlands)

    Khan, M. Tanweer; van Dijl, Jan Maarten; Harmsen, Hermie J M

    2014-01-01

    The beneficial human gut microbe Faecalibacterium prausnitzii is a 'probiotic of the future' since it produces high amounts of butyrate and anti-inflammatory compounds. However, this bacterium is highly oxygen-senstive, making it notoriously difficult to cultivate and preserve. This has so far

  17. Phosphorus uptake of an arbuscular mycorrhizal fungus is not effected by the biocontrol bacterium ¤Burkholderia cepacia¤

    DEFF Research Database (Denmark)

    Ravnskov, S.; Larsen, J.; Jakobsen, I.

    2002-01-01

    The biocontrol bacterium Burkholderia cepacia is known to suppress a broad range of root pathogenic fungi, while its impact on other beneficial non-target organisms such as arbuscular mycorrhizal (AM) fungi is unknown. Direct interactions between five B. cepacia strains and the AM fungus, Glomus ...

  18. [INFLUENCE OF AZOSPIRILLUM BRASILENSE 10/1 ON ASSOCIATIVE NITROGEN FIXATION AND INTRAVARIETAL POLYMORPHISM OF SPRING TRITICALE].

    Science.gov (United States)

    Patika, V P; Nadkernichna, O V; Shahovnina, O O

    2015-01-01

    It is shown, that the perspective Ukrainian sorts of spring triticale characterizes by considerable polymorphism by associative N2-fixing ability in root zone of plants. Application of active strain Azospirillum brasilense 10/1 promotes the decline of variability of this sign within the limits of sort, increase potential nitrogen activity is on the average in 3,2-4,7 times and also distributing normalizations in the selections of the inoculated plants.

  19. 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.

  20. 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.

  1. 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.

  2. Comparison of two Cellulomonas strains and their interaction with Azospirillum brasilense in degradation of wheat straw and associated nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    Halsall, D.M.; Gibson, A.H.

    1986-04-01

    A mutant strain of Cellulomonas sp. CS1-17 was compared with Cellulomonas gelida 2480 as the cellulolytic component of a mixed culture which was responsible for the breakdown of wheat straw to support asymbiotic nitrogen fixation by Azospirillum brasilense Sp7 (ATCC 29145). Cellulomonas sp. strain CS1-17 was more efficient than was C. gelida in cellulose breakdown at lower oxygen concentrations and, in mixed culture with A. brasilense, it supported higher nitrogenase activity(C/sub 2/H/sub 2/ reduction) and nitrogen fixation with straw as the carbon source. Based on gravimetric determinations of straw breakdown and total N determinations, the efficiency of nitrogen fixation was 72 and 63 mg of N per g of straw utilized for the mixtures containing Cellulomonas sp. and C. gelida, respectively. Both Cellulomonas spp. and Azospirillum spp. exhibited a wide range of pH tolerance. When introduced into sterilized soil, the Cellulomonas sp.-Azospirillum brasilense association was more effective in nitrogen fixation at a pH of 7.0 than at the native soil pH (5.6). This was also true of the indigenous diazotrophic microflora of this soil. The potential implications of this work to the field situation are discussed. 16 references.

  3. Improvement of Canola (Brassica napus L.) Inoculated with Rhizobium, Azospirillum and/or Mycorrhizal Fungi Under Salinity Stress

    International Nuclear Information System (INIS)

    El-Ghandour, I. A.; Galal, Y.G; Ebraheem, Rabab M.M.; Yousef, Khayria A.

    2004-01-01

    Bio fertilization technology was applied for improving canola plant growth and nutrient acquisition in sandy saline soil ,as a biological mean used to develop plant growth and nutrient uptake under salinity stress. Canola was cultivated in pots packed at rate of 7 kg saline sandy soil pot -1 , and inoculated with Rhizobium leguminosarum biovar viceae, Azospirillum brasilense strain no. 40 and arbuscular mycorrhizal fungi either solely or in combinations of them. Nitrogen fertilizer was added in form ( 15 NH 4 ) 2 SO 4 with 5% 15 N atom excess at rate of 0.99 g N pot -1 . Maximum dry matter accumulation induced by composite inoculation (Rh + Azo + AM). Na concentrations were frequently affected by Rhizobium and /or mycorrhizae while K was affected by Azospirillum and /or mycorrhizae. Azospirillum enhanced Ca uptake whereas Mg content was responded well to composite inoculants of Rh + Azo + AM. Dual inoculation with Rh + Azo resulted in the highest values of N uptake by plant. Similar effect was noticed with P uptake when dual inoculums of Azo + AM were applied. Data of 15 N isotope showed that the highest portion and value of N 2 -fixed was recorded with composite inoculums followed by dual inoculations. On the other hand, the infection with AM fungi gave the highest proportion of N derived from fertilizer as compared to other inoculants or uninoculated control. In the same trend, the fertilizer use efficiency (FUE%) was enhanced by AM infection. Dual inoculums of Rh + Azo induced highest content of proline in leaves. (Authors)

  4. The Effects of Carboxin-thiram on Associative Relationships between Azospirillum Species and Wheat (Chamran Cultivar

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    F. rejali

    2017-03-01

    Full Text Available Introduction: Biofertilizers have been identified as alternative to chemical fertilizers to increase soil fertility and crop production in sustainable farming systems. One of the most useful kind of biofertilizers include plant growth promoting rhizobacteria (PGPR. Azospirillum is an associative rhizobacteria which can be very useful for plants such as wheat. It can help plant by fixing nitrogen through biological way, causing root development, plant strength improvement in primary phases, causing germination percent increment, improving plant tolerance in stress situations (drought, salinity, soil compaction and pathogens, secreting plant promoting hormones like cytokinin, Oxin and finally yield increment will be observable. Modern agriculture largely relies on the extensive application of agrochemicals, including inorganic fertilizers and pesticides. Although pesticides are important, their effects on nontarget organisms are of great concern because this poses a risk to the entire ecological system. The fungicides may also adversely affect the soil microflora, especially the types of microorganisms that can applied to seeds as bacterial inoculants. Considering useful effects of plant growth promoting rhizobacteria especially Azospirillum on Wheat, this study was done in order to survey interaction effects between fungicide and available biofertilizers in Iran market. Materials and Methods: Effect of carboxin tiram in 2 levels (applied, non-applied as fungicide, on efficacy of wheat plant (Chamran Cultivar and final crop yields under association conditions with 5 Azospirillum species (A.brasilense, A.lipoferum, A.halopraeferense, A.irakense, A.sp using powdery and liquid formulation were studied in a greenhouse test for four months in Soil and Water Research Institute.At first some properties of used soil, including soil texture, pH, EC,organic carbon and available soil K, P, Fe, Zn, Mn and Cu were measured by laboratory methods.Nutrient Broth

  5. Coal beneficiation by gas agglomeration

    Science.gov (United States)

    Wheelock, Thomas D.; Meiyu, Shen

    2003-10-14

    Coal beneficiation is achieved by suspending coal fines in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates of the fines adhered by the gas bubbles. The agglomerates are separated, recovered and resuspended in water. Thereafter, the pressure on the suspension is increased above atmospheric to deagglomerate, since the gas bubbles are then re-dissolved in the water. During the deagglomeration step, the mineral matter is dispersed, and when the pressure is released, the coal portion of the deagglomerated gas-saturated water mixture reagglomerates, with the small bubbles now coming out of the solution. The reagglomerate can then be separated to provide purified coal fines without the mineral matter.

  6. Is vitamin C supplementation beneficial?

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens; Poulsen, Henrik Enghusen

    2010-01-01

    of the benefit:harm ratio of antioxidant supplements. We have examined the literature on vitamin C intervention with the intention of drawing a conclusion on its possible beneficial or deleterious effect on health and the result is discouraging. One of several important issues is that vitamin C uptake is tightly...... controlled, resulting in a wide-ranging bioavailability depending on the current vitamin C status. Lack of proper selection criteria dominates the currently available literature. Thus, while supplementation with vitamin C is likely to be without effect for the majority of the Western population due...... to saturation through their normal diet, there could be a large subpopulation with a potential health problem that remains uninvestigated. The present review discusses the relevance of the available literature on vitamin C supplementation and proposes guidelines for future randomised intervention trials....

  7. [A STUDY OF THE ISOLATED BACTERIOPHAGE ΦAB-SP7 ADSORPTION ON THE CELL SURFACE OF THE AZOSPIRILLUM BRASILENSE SP7].

    Science.gov (United States)

    Guliy, O I; Karavaeva, O A; Velikov, V A; Sokolov, O I; Pavily, S A; Larionova, O S; Burov, A M; Ignatov, O V

    2016-01-01

    The bacteriophage ΦAb-Sp7 was isolated from the cells of the Azospirillum brasilense Sp7. The morphology, size of the gram-negative colonies, and range of lytic activity against other strains and species of the genus Azospirillum was tested. The isolated phage DNA was examined using electrophoretic and restriction analysis, and the size of the genome were established. The electron microscopy. resuIts show that the phage (capsid) has a strand-like form. The electron microscopy study of the bacteriophage ΦAb-Sp7 adsorption on the A. brasilense Sp7 bacterial surface was performed.

  8. Growth and yield of corn hybrids in response to association with Azospirillum brasilense and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Deniele Marini

    2015-02-01

    Full Text Available There is a growing interest in optimizing the positive effects of the association between Azospirillum bacteria and corn crop in order to reduce the use of nitrogen fertilizers. This study aimed to evaluate the inoculation efficiency of an A. brasilense-based commercial product in association with different rates of nitrogen fertilization in two corn genotypes. The experiment was arranged in a 2 x 2 x 5 factorial randomized block design, with four replications. The treatments consisted of two corn hybrids (30F53 and CD386; with and without inoculation with a commercial product based on A. brasilense and five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1. The variables plant height, basal stem diameter, leaf area, shoot dry matter, leaf nitrogen content, length and diameter of the cob, weight of 100 grains and grain yield were evaluated. Inoculation with A. brasilense provided increases of 11 and 12% in leaf area and shoot dry matter, respectively. There were differences in the response of the corn hybrids for most variables and the increase in nitrogen supply provided increments in the growth and yield of corn.

  9. Purification and binding analysis of the nitrogen fixation regulatory NifA protein from Azospirillum brasilense

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    L.M.P. Passaglia

    1998-11-01

    Full Text Available NifA protein activates transcription of nitrogen fixation operons by the alternative sigma54 holoenzyme form of RNA polymerase. This protein binds to a well-defined upstream activator sequence (UAS located at the -200/-100 position of nif promoters with the consensus motif TGT-N10-ACA. NifA of Azospirillum brasilense was purified in the form of a glutathione-S-transferase (GST-NifA fusion protein and proteolytic release of GST yielded inactive and partially soluble NifA. However, the purified NifA was able to induce the production of specific anti-A. brasilense NifA-antiserum that recognized NifA from A. brasilense but not from K. pneumoniae. Both GST-NifA and NifA expressed from the E. coli tac promoter are able to activate transcription from the nifHDK promoter but only in an A. brasilense background. In order to investigate the mechanism that regulates NifA binding capacity we have used E. coli total protein extracts expressing A. brasilense nifA in mobility shift assays. DNA fragments carrying the two overlapping, wild-type or mutated UAS motifs present in the nifH promoter region revealed a retarded band of related size. These data show that the binding activity present in the C-terminal domain of A. brasilense NifA protein is still functional even in the presence of oxygen.

  10. Tiller density and tillering on Brachiaria brizantha cv. Marandu pastures inoculated with Azospirillum brasilense

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    B.C. Pedreira

    Full Text Available ABSTRACT The objective of this study is to verify the population density and the dynamics of tillering in the Marandu palisade grass sward subjected to nitrogen (N fertilization strategies, characterized by the N supply via urea or bacterial inoculant (Azospirillum brasilense. The treatments comprised of four nitrogen fertilization strategies: (A Without fertilization, (B 80 kg N/ha, (C inoculant (A. brasilense, and (D 80 kg N/ha + inoculant, distributed in a randomized complete block design, with three replications. The nitrogen supply strategies were evaluated during six periods: October, November, and December (2012 as well as January, March, and April (2013. The nitrogen dose or inoculant had no effect on the tiller appearance rate (TAR, tiller mortality rate (TMR, tiller survival rate (TSR, or tiller population density (TPD. However, these variables were influenced by the season. The TAR and TSR were higher at the beginning of the experimental period (October and lower towards the end of the period (March-April, whereas, TMR and TPD exhibited the opposite behavior, with lower values in October and higher from January onward. Neither the nitrogen nor the inoculant influenced the population dynamics of the tillers in Marandu palisade grass.

  11. Co-inoculation of Azospirillum brasilense and Herbaspirillum seropedicae in maize

    Directory of Open Access Journals (Sweden)

    Janaína Dartora

    2016-06-01

    Full Text Available ABSTRACT Bacteria from the genera Azospirillum and Herbaspirillum have been associated with increments in maize yield. The aim of this study was to evaluate the maize yield and nutritional content in response to inoculation with A. brasilense and H. seropediceae in association with nitrogen (N fertilization. The experimental design was randomized blocks in a 4 x 5 factorial scheme, with four replicates. The treatments consisted of seed inoculation (control without N and inoculation, A. brasilense strain - AbV5, H. seropediceae strain - SMR1 and co-inoculation AbV5 + SMR1 and N doses (0, 40, 80, 120 and 160 kg ha-1. The following variables were evaluated: ear insertion height, ear length, ear diameter, number of rows per ear, number of grains per row, ear weight, yield and NPK contents in leaves and grains. There was no interaction between the factors studied. Co-inoculation with the strains promoted increments of 12% in leaf P content, compared with control, and N fertilization promoted increase in yield and leaf P content up to the maximum dose studied.

  12. Electro-optical study of the exposure of Azospirillum brasilense carbohydrate epitopes.

    Science.gov (United States)

    Guliy, Olga I; Matora, Larisa Yu; Dykman, Lev A; Staroverov, Sergey A; Burygin, Gennady L; Bunin, Viktor D; Burov, Andrei M; Ignatov, Oleg V

    2015-01-01

    The exposure of Azospirillum brasilense carbohydrate epitopes was investigated by electro-optical analysis of bacterial cell suspensions. To study changes in the electro-optical (EO) properties of the suspensions, we used antibodies generated to the complete lipopolysaccharide of A. brasilense type strain Sp7 and also antibodies to the smooth and rough O polysaccharides of Sp7. After 18 hr of culture growth, the EO signal of the suspension treated with antibodies to smooth O polysaccharide was approximately 20% lower than that of the suspension treated with antibodies to complete lipopolysaccharide (control). After 72 hr of culture growth, the strongest EO signal was observed for the cells treated with antibodies to rough O polysaccharide (approximately 46% greater than the control), whereas for the cells treated with antibodies to smooth O polysaccharide, it was much lower (approximately 23% of the control). These data were confirmed by electron microscopy. The results of the study may have importance for the rapid evaluation of changes in lipopolysaccharide form in microbial biotechnology, when the antigenic composition of the bacterial surface requires close control.

  13. Components of corn crop yield under inoculation with Azospirillum brasilense using integrated crop-livestock system

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    Marcos da Silva Brum

    2016-09-01

    Full Text Available The objective of this study was to evaluate the agronomic characteristics of corn seed inoculated with Azospirillum brasilense, grown on black oat and ryegrass straw, and managed under different grazing strategies and doses of nitrogen. The experiment was conducted in Santa Maria, Rio Grande do Sul State, Brazil, during two agricultural seasons (2012/2013 and 2013/2014 in a randomized, complete block design with three replications. In the winter period, black oat and ryegrass straw were managed at different grazing heights by sheep (0.30, 0.20, 0.10 m, conventional grazing, and no grazing with three doses of nitrogen (0, 50, and 100 kg ha-1, with or without inoculation by A. brasilense. We used the hybrid Pioneer (P1630H® in 2012 and the hybrid Agroeste (AS 1551® in 2013. The height of corn plants was greater when they were grown on black oat and ryegrass straw, and the absence of grazing favored productivity. Under drought conditions, the application of nitrogen to the pasture favored corn development, increasing plant height, ear height, and stem diameter. Inoculation with A. brasilense had a positive effect on the characteristics of yield and productivity of corn, independent of growing season and hybrid used.

  14. A hybrid two-component system protein from Azospirillum brasilense Sp7 was involved in chemotaxis.

    Science.gov (United States)

    Cui, Yanhua; Tu, Ran; Wu, Lixian; Hong, Yuanyuan; Chen, Sanfeng

    2011-09-20

    We here report the sequence and functional analysis of org35 of Azospirillum brasilense Sp7, which was originally identified to be able to interact with NifA in yeast-two-hybrid system. The org35 encodes a hybrid two-component system protein, including N-terminal PAS domains, a histidine kinase (HPK) domain and a response regulator (RR) domain in C-terminal. To determine the function of the Org35, a deletion-insertion mutant in PAS domain [named Sp7353] and a complemental strain Sp7353C were constructed. The mutant had reduced chemotaxis ability compared to that of wild-type, and the complemental strain was similar to the wild-type strain. These data suggested that the A. brasilense org35 played a key role in chemotaxis. Variants containing different domains of the org35 were expressed, and the functions of these domains were studied in vitro. Phosphorylation assays in vitro demonstrated that the HPK domain of Org35 possessed the autokinase activity and that the phosphorylated HPK was able to transfer phosphate groups to the RR domain. The result indicated Org35 was a phosphorylation-communicating protein. Copyright © 2010 Elsevier GmbH. All rights reserved.

  15. Nitrogen translocation in wheat inoculated with Azospirillum and fertilized with nitrogen

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    RODRIGUES OSMAR

    2000-01-01

    Full Text Available The productivity and the translocation of assimilates and nitrogen (N were compared after inoculation of wheat (Triticum aestivum L., cv. BR-23 seeds with two strains of Azospirillum brasilense (strains 245 and JA 04 under field conditions. The inoculation of wheat seeds was done with a peat inoculant at sowing time. Plant material for evaluations were collected at anthesis and maturity. No differences in grain yield and in the translocation of assimilates resulting from inoculation were detected. Differences were observed in relation to N rates (0, 15, and 60 kg ha-1. N content in the grain increased significantly in the bacteria-inoculated treatments in which N was not added. This increase in N content in the grain with inoculation was probably due to higher N uptake after anthesis without any significant contribution on the grain yield. Such increment was of 8.4 kg ha-1 of N representing 66% more N than in no inoculated treatment. Regardless of the inoculation and the rate of N applied, it was observed that about 70% of the N accumulated at anthesis was translocated from vegetative parts to the grain.

  16. Rhizobial Inoculation, Alone or Coinoculated with Azospirillum brasilense, Promotes Growth of Wetland Rice

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    Leandro Hahn

    Full Text Available ABSTRACT Rhizobia and associative bacteria promote growth in rice plants (Oryza sativa L. through a series of mechanisms, but most studies on inoculation have been performed based on inoculation with these bacteria in a separate or singular manner. The objective of this study was to assess the efficiency of single/isolated inoculation and inoculation combined with symbiotic rhizobia from forage legume and with Azospirillum brasilense on promoting growth and the root colonization process in wetland rice. Two rhizobia among four isolates from a greenhouse and a laboratory experiment were selected that efficiently promoted seed germination and rice plant growth in a sterilized substrate and in soil. The two most efficient isolates (UFRGS Vp16 and UFRGS Lc348 were inoculated alone or in combination with a commercial product containing A. brasilense in two field experiments using two wetland rice cultivars over two growing seasons. In the field experiments, these isolates coinoculated with A. brasilense promoted larger increases in the agronomic variables of wetland rice compared to the control without inoculation. Confocal laser microscopy confirmed the presence of inoculated bacteria tagged with gfp (UFRGS Vp16, UFRGS Lc348, and A. brasilense colonizing the root surface of the rice seedlings, mainly in the root hairs and lateral roots.

  17. [Detection of putative polysaccharide biosynthesis genes in Azospirillum brasilense strains from serogroups I and II].

    Science.gov (United States)

    Petrova, L P; Prilipov, A G; Katsy, E I

    2017-01-01

    It is known that in Azospirillum brasilense strains Sp245 and SR75 included in serogroup I, the repeat units of their O-polysaccharides consist of five residues of D-rhamnose, and in strain SR15, of four; and the heteropolymeric O-polysaccharide of A. brasilense type strain Sp7 from serogroup II contains not less than five types of repeat units. In the present work, a complex of nondegenerate primers to the genes of A. brasilense Sp245 plasmids AZOBR_p6, AZOBR_p3, and AZOBR_p2, which encode putative enzymes for the biosynthesis of core oligosaccharide and O-polysaccharide of lipopolysaccharide, capsular polysaccharides, and exopolysaccharides, was proposed. By using the designed primers, products of the expected sizes were synthesized in polymerase chain reactions on genomic DNA of A. brasilense Sp245, SR75, SR15, and Sp7 in 36, 29, 23, and 12 cases, respectively. As a result of sequencing of a number of amplicons, a high (86–99%) level of identity of the corresponding putative polysaccharide biosynthesis genes in three A. brasilense strains from serogroup I was detected. In a blotting-hybridization reaction with the biotin-labeled DNA of the A. brasilense gene AZOBR_p60122 coding for putative permease of the ABC transporter of polysaccharides, localization of the homologous gene in ~120-MDa plasmids of the bacteria A. brasilense SR15 and SR75 was revealed.

  18. Expressed sequence tags related to nitrogen metabolism in maize inoculated with Azospirillum brasilense.

    Science.gov (United States)

    Pereira-Defilippi, L; Pereira, E M; Silva, F M; Moro, G V

    2017-05-31

    The relative quantitative real-time expression of two expressed sequence tags (ESTs) codifying for key enzymes in nitrogen metabolism in maize, nitrate reductase (ZmNR), and glutamine synthetase (ZmGln1-3) was performed for genotypes inoculated with Azospirillum brasilense. Two commercial single-cross hybrids (AG7098 and 2B707) and two experimental synthetic varieties (V2 and V4) were raised under controlled greenhouse conditions, in six treatment groups corresponding to different forms of inoculation and different levels of nitrogen application by top-dressing. The genotypes presented distinct responses to inoculation with A. brasilense. Increases in the expression of ZmNR were observed for the hybrids, while V4 only displayed a greater level of expression when the plants received nitrogenous fertilization by top-dressing and there was no inoculation. The expression of the ZmGln1-3EST was induced by A. brasilense in the hybrids and the variety V4. In contrast, the variety V2 did not respond to inoculation.

  19. Plant yield and nitrogen content of a digitgrass in response to azospirillum inoculation

    Energy Technology Data Exchange (ETDEWEB)

    Schank, S.C.; Weier, K.L.; MacRae, I.C.

    1981-02-01

    Two Australian soils, a vertisol (pH 6.8, 0.299% N) and a sandy yellow podzol (pH 6.2, 0.042% N), were used with digitgrass, Digitaria sp. X46-2 (PI 421785), in a growth room experiment. Comparisons were made between plants inoculated with live and autoclaved bacterial suspensions of Australian and Brazilian isolates of Azospirillum brasilense. Seedlings were inoculated on days 10 and 35. Acetylene-reducing activity was measured five times during the experiment. Dry matter yields of the digitgrass on the podzol (low N) inoculated with liver bacteria were 23% higher than those of the controls. On the vertisol (high N), yield increases from inoculation with live bacteria were 8.5%. The higher-yielding plants had significantly lower precent nitrogen, but when total nitrogen of the tops was calculated, the inoculated plants had a higher total N than did the controls (P = 0.04). Acetylene-reducing activity was variable in the experiment, ranging from 0.5 to 11.9 mu mol of C2H2 core -1 day -1. Live bacterial treatment induced a proliferation of roots, possible earlier maturity, higher percent dry matter, and a higher total N in the tops. (Refs. 21).

  20. AZOSPIRILLUM BRASILENSE VIA FOLIAR E DOSES DE NITROGÊNIO EM COBERTURA NA CULTURA DO TRIGO NA REGIÃO DE ITAPEVA-SP / SPRAYING WITH AZOSPIRILLUM ON WHEAT LEAF AND NITROGEN COVERAGE RATES IN ITAPEVA-SP

    Directory of Open Access Journals (Sweden)

    J. P. Ferreira

    2017-06-01

    Full Text Available A utilização de bactérias diazotróficas na agricultura, especialmente em gramíneas, tem por finalidade incrementar a produção e produtividade aliando com menor dose ou supressão das fontes nitrogenadas aplicadas para fertilização do solo. Diante disso, o trabalho objetivou avaliar a viabilidade da inoculação de Azospirillum brasilense via foliar com doses de nitrogênio em cobertura na produção e produtividade do trigo. O experimento foi implantado na Fazenda Bom Viver, Bairro dos Prestes em Itapeva-SP, na safra de 2016, sendo realizado em plantio direto (SPC em área de sucessão soja e milho safrinha. Os tratamentos foram em esquema fatorial 2x4 em blocos ao acaso (DBC sendo aplicado a formulação liquida de Azospirillum brasiliense (AbV5 com 2x108 células viáveis mL-1 na dose de 0,5 L.ha-1 via foliar e sem aplicação e posterior adubação nitrogenada com 0; 30; 60 e 90 kg.ha-1 em cobertura. Tanto a aplicação foliar de Azospirillum como a cobertura de N, foram aplicadas após 30 dias da semeadura (30 DAS. A variedade de trigo utilizada no plantio foi o Sinuelo, com manejo adotado pelo proprietário da área com aplicação de regulador de crescimento. Foram realizadas as avaliações a campo das plantas, medindo-se: a altura das plantas; espigas por metro linear; número de grãos por espiguetas; peso hectolítro; massa de mil grãos e produtividade. Pelos resultados obtidos, houve maior altura de plantas com o aumento das doses de nitrogênio em cobertura. A inoculação de Azospirillum brasiliense via foliar não mostrou interação entre as doses de nitrogênio em cobertura, não havendo estatisticamente incremento nos componentes de produtividade do trigo.

  1. N-acyl-homoserine lactone-mediated quorum-sensing in Azospirillum: an exception rather than a rule.

    Science.gov (United States)

    Vial, Ludovic; Cuny, Caroline; Gluchoff-Fiasson, Katia; Comte, Gilles; Oger, Phil M; Faure, Denis; Dessaux, Yves; Bally, René; Wisniewski-Dyé, Florence

    2006-11-01

    Forty Azospirillum strains were tested for their ability to synthesize N-acyl-homoserine lactones (AHLs). AHL production was detected for four strains belonging to the lipoferum species and isolated from a rice rhizosphere. AHL molecules were structurally identified for two strains: Azospirillum lipoferum TVV3 produces 3O,C(8)-HSL (N-3-oxo-octanoyl-homoserine-lactone), C(8)-HSL (N-3-octanoyl-homoserine-lactone), 3O,C(10)-HSL (N-3-oxo-decanoyl-homoserine-lactone), 3OH,C(10)-HSL (N-3-hydroxy-decanoyl-homoserine-lactone) and C(10)-HSL (N-3-decanoyl-homoserine-lactone), whereas A. lipoferum B518 produced 3O,C(6)-HSL (N-3-oxo-hexanoyl-homoserine-lactone), C(6)-HSL (N-3-hexanoyl-homoserine-lactone), 3O,C(8)-HSL, 3OH,C(8)-HSL and C(8)-HSL. Genes involved in AHL production were characterized for A. lipoferum TVV3 by generating a genomic library and complementing an AHL-deficient strain with sensor capabilities. Those genes, designated alpI and alpR, were found to belong to the luxI and luxR families, respectively. When cloned in a suitable heterologous host, alpI and alpR could direct the synthesis of the five cognate AHLs present in A. lipoferum TVV3. These two adjacent genes were found to be located on a 85 kb plasmid. Southern hybridization experiments with probes alpI/R indicated that genes involved in AHL production in the three other AHL-producing strains were not closely related to alpI and alpR. This study demonstrates that AHL-based quorum-sensing is not widespread among the genus Azospirillum and could be found only in some A. lipoferum strains.

  2. Identification of an O-linked repetitive glycan chain of the polar flagellum flagellin of Azospirillum brasilense Sp7.

    Science.gov (United States)

    Belyakov, Alexei Ye; Burygin, Gennady L; Arbatsky, Nikolai P; Shashkov, Alexander S; Selivanov, Nikolai Yu; Matora, Larisa Yu; Knirel, Yuriy A; Shchyogolev, Sergei Yu

    2012-11-01

    This is the first report to have identified an O-linked repetitive glycan in bacterial flagellin, a structural protein of the flagellum. Studies by sugar analysis, Smith degradation, (1)H and (13)C NMR spectroscopy, and mass spectrometry showed that the glycan chains of the polar flagellum flagellin of the plant-growth-promoting rhizobacterium Azospirillum brasilense Sp7 are represented by a polysaccharide with a molecular mass of 7.7 kDa, which has a branched tetrasaccharide repeating unit of the following structure: Copyright © 2012. Published by Elsevier Ltd.

  3. Chemical synthesis of the tetrasaccharide repeating unit of the O-polysaccharide isolated from Azospirillum brasilense SR80.

    Science.gov (United States)

    Sarkar, Vikramjit; Mukhopadhyay, Balaram

    2015-04-10

    A linear strategy has been developed for the synthesis of the tetrasaccharide repeating unit of the O-polysaccharide from Azospirillum brasilense SR80. Stepwise glycosylation of the rationally protected thioglycoside donors activated by NIS in the presence of La(OTf)3 furnished the target tetrasaccharide. The glycosylation reactions resulted in the formation of the desired linkage with absolute stereoselectivity and afforded the required derivatives in good to excellent yields. The phthalimido group has been used as the precursor of the desired acetamido group to meet the requirement of 1,2-trans glycosidic linkage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2013-10-18

    Lipopolysaccharide was obtained by phenol-water extraction from dried bacterial cells of Azospirillum brasilense type strain Sp7. Mild acid hydrolysis of the lipopolysaccharide followed by GPC on Sephadex G-50 resulted in a polysaccharide mixture, which was studied by composition and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy. The following polysaccharide structures were established, where italics indicate a non-stoichiometric (∼40%) 2-O-methylation of l-rhamnose. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Identificação de genes de Azospirillum amazonense diferencialmente expressos em resposta à disponibilidade de nitrogênio

    OpenAIRE

    Fernando Hayashi Sant Anna

    2007-01-01

    Bactérias do gênero Azospirillum possuem a capacidade de promover o crescimento vegetal através de mecanismos que não estão claramente elucidados. Contudo, essa característica é muito estudada, tendo em vista a possibilidade de utilizar esses microrganismos na agricultura em detrimento do uso indiscriminado de fertilizantes industriais, que poluem o meio ambiente. O solo é um ambiente altamente variável quanto à disponibilidade de nutrientes e quanto a fatores físico-químicos, por isso, bacté...

  6. Convergent synthesis of a tetrasaccharide repeating unit of the O-specific polysaccharide from the cell wall lipopolysaccharide of Azospirillum brasilense strain Sp7

    Directory of Open Access Journals (Sweden)

    Pintu Kumar Mandal

    2014-01-01

    Full Text Available A straightforward convergent synthesis has been carried out for the tetrasaccharide repeating unit of the O-specific cell wall lipopolysaccharide of the strain Sp7 of Azospirillum brasilense. The target tetrasaccharide has been synthesized from suitably protected monosaccharide intermediates in 42% overall yield in seven steps by using a [2 + 2] block glycosylation approach.

  7. Zymomonas mobilis: a bacterium for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Baratti, J.C.; Bu' Lock, J.D.

    1986-01-01

    Zymomonas mobilis is a facultative anaerobic gram negative bacterium first isolated in tropical countries from alcoholic beverages like the African palm wine, the Mexican pulque and also as a contaminant of cider (cider sickness) or beer in the European countries. It is one of the few facultative anaerobic bacteria degrading glucose by the Entner-Doudoroff pathway usually found in strictly aerobic microorganisms. Some work was devoted to this bacterium in the 50s and 60s and was reviewed by Swings and De Ley in their classical paper published in 1977. During the 70s there was very little work on the bacterium until 1979 and the first report by the Australian group of P.L. Rogers on the great potentialities of Z. mobilis for ethanol production. At that time the petroleum crisis had led the developed countries to search for alternative fuel from renewable resources. The Australian group clearly demonstrated the advantages of the bacterium compared to the yeasts traditionally used for the alcoholic fermentation. As a result, there was a considerable burst in the Zymomonas literature which started from nearly zero in the late 70s to attain 70 papers published in the field in 1984. In this article, papers published from 1982 to 1986 are reviewed.

  8. Microflora of urogenital tract in pregnancy with asymptomatic bacterium

    International Nuclear Information System (INIS)

    Abdullaeva, R.A.

    2006-01-01

    The article contains results of research interrelationship from colonization of vagina and urinary tract diseases. E.coli one of the main factors in development asymptomatic bacterium. Presented high effects of penicillin medicaments and nitrofurans in treatment of asymptomatic bacterium

  9. Engineering a wild fast-growing Mycoplasma bacterium to generate ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-01-12

    Jan 12, 2018 ... The CCPP bacterium causes sick animals to experience severe symptoms ... because antibiotic treatment does not eliminate the responsible bacterium. ... To develop a fast growing CCPP vaccine for cheaper production and ...

  10. In vitro propagation of fraser photinia using Azospirillum-mediated root development.

    Science.gov (United States)

    Llorente, Berta E; Larraburu, Ezequiel E

    2013-01-01

    Fraser photinia (Photinia × fraseri Dress.) is a woody plant of high ornamental value. The traditional propagation system for photinia is by rooting apical cuttings using highly concentrated auxin treatments. However, photinia micropropagation is an effective alternative to traditional in vivo propagation which is affected by the seasonal supply of cuttings, the long time required to obtain new plants, and the difficulties in rooting some clones.A protocol for in vitro propagation of fraser photinia using the plant growth-promoting ability of some rhizobacteria is described here. Bacterial inoculation is a new tool in micropropagation protocols that improves plant development in in vitro culture. Shoots culture on a medium containing MS macro- and microelements, Gamborg's vitamins (BM), N (6)-benzyladenine (BA, 11.1 μM), and gibberellic acid (1.3 μM) produce well-established explants. Proliferation on BM medium supplemented with 4.4 μM BA results in four times the number of shoots per initial shoot that develops monthly. Consequently, there is a continuous supply of plant material since shoot production is independent of season. Azospirillum brasilense inoculation, after 49.2 μM indole-3-butyric acid pulse treatment, stimulates early rooting of photinia shoots and produces significant increase in root fresh and dry weights, root surface area, and shoot fresh and dry weights in comparison with controls. Furthermore, inoculated in vitro photinia plants show anatomical and morphological changes that might lead to better adaptation in ex vitro conditions after transplanting, compared with the control plants.

  11. Chemical soil attributes after wheat cropping under nitrogen fertilization and inoculation with Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    Fernando Shintate Galindo

    2017-05-01

    Full Text Available Azospirillum brasilense plays an important role in biological nitrogen fixation (BNF in grasses. However, further studies are needed to define how much mineral N can be applied while simultaneously maintaining BNF contribution and maximizing crop yield and to determine the impact of these practices on soil fertility. Thus, we aimed to investigate the effect of inoculation with A. brasilense, in conjunction with varying N doses and sources in a Cerrado soil, on soil chemical attributes after two years of irrigated wheat production. The experiment was initiated in Selvíria - MS under no-tillage production in an Oxisol in 2014 and 2015. The experimental design was a randomized block design with four replications, and treatments were arranged in a 2 x 5 x 2 factorial arrangement as follows: two N sources (urea and Super N - urea with inhibitor of the enzyme urease NBPT (N - (n-butyl thiophosphoric triamide, five N rates (0, 50, 100, 150 and 200 kg ha-1, and with or without seed inoculation with A. brasilense. The increase in N rates did not influence the chemical soil attributes. Super N acidified the soil more compared to urea. A. brasilense inoculation reduced the effect of soil acidification in intensive irrigated wheat cultivation; however, the base extraction was higher, resulting in a lower soil CEC after cultivation with inoculation. Therefore, the cultivation of wheat inoculated with A. brasilense was not harmful to soil fertility because it did not reduce the base saturation and organic matter content (P, K, Ca, Mg, and S.

  12. Azospirillum brasilense Chemotaxis Depends on Two Signaling Pathways Regulating Distinct Motility Parameters.

    Science.gov (United States)

    Mukherjee, Tanmoy; Kumar, Dhivya; Burriss, Nathan; Xie, Zhihong; Alexandre, Gladys

    2016-06-15

    The genomes of most motile bacteria encode two or more chemotaxis (Che) systems, but their functions have been characterized in only a few model systems. Azospirillum brasilense is a motile soil alphaproteobacterium able to colonize the rhizosphere of cereals. In response to an attractant, motile A. brasilense cells transiently increase swimming speed and suppress reversals. The Che1 chemotaxis pathway was previously shown to regulate changes in the swimming speed, but it has a minor role in chemotaxis and root surface colonization. Here, we show that a second chemotaxis system, named Che4, regulates the probability of swimming reversals and is the major signaling pathway for chemotaxis and wheat root surface colonization. Experimental evidence indicates that Che1 and Che4 are functionally linked to coordinate changes in the swimming motility pattern in response to attractants. The effect of Che1 on swimming speed is shown to enhance the aerotactic response of A. brasilense in gradients, likely providing the cells with a competitive advantage in the rhizosphere. Together, the results illustrate a novel mechanism by which motile bacteria utilize two chemotaxis pathways regulating distinct motility parameters to alter movement in gradients and enhance the chemotactic advantage. Chemotaxis provides motile bacteria with a competitive advantage in the colonization of diverse niches and is a function enriched in rhizosphere bacterial communities, with most species possessing at least two chemotaxis systems. Here, we identify the mechanism by which cells may derive a significant chemotactic advantage using two chemotaxis pathways that ultimately regulate distinct motility parameters. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. Hydrogenase activity in Azospirillum brasilense is inhibited by nitrite, nitric oxide, carbon monoxide, and acetylene

    Energy Technology Data Exchange (ETDEWEB)

    Tibelius, K.H.; Knowles, R.

    1984-10-01

    Nitrite, NO, CO, and C/sub 2/H/sub 2/ inhibited O/sub 2/-dependent H/sub 2/ uptake (H/sup 3/H oxidation) in denitrifying Azospirillum brasilense Sp7 grown anaerobically on N/sub 2/O or NO/sub 3//sup -/. The apparent K/sub i/ values for inhibition of O/sub 2/-dependent H/sub 2/ uptake were 20 ..mu..M for NO/sub 2//sup -/, 0.4 ..mu..M for NO, 28 ..mu..M for CO, and 88 ..mu..M for C/sub 2/H/sub 2/. These inhibitors also affected methylene blue-dependent H/sub 2/ uptake, presumably by acting directly on the hydrogenase. Nitrite and NO inhibited H/sub 2/ uptake irreversibly, whereas inhibition due to CO was easily reversed by repeatedly evacuating and backfilling with N/sub 2/. The C/sub 2/H/sub 2/ inhibition was not readily reversed, partly due to difficulty in removing the last traces of this gas from solution. The NO/sub 2//sup -/ inhibition of malate-dependent respiration was readily reversed by repeatedly washing the cells, in contrast to the effect of NO/sub 2//sup -/ on H/sub 2/-dependent respiration. These results suggest that the low hydrogenase activities observed in NO/sub 3//sup -/-grown cultures of A. brasilense may be due to the irreversible inhibition of hydrogenase by NO/sub 2//sup -/ and NO produced by NO/sub 3//sup -/ reduction.

  14. CRECIMIENTO DE Cedrela odorata L. BIOFERTILIZADA CON Rhizophagus intraradices y Azospirillum brasilense EN VIVERO

    Directory of Open Access Journals (Sweden)

    Juan F. Aguirre-Medina

    2014-01-01

    Full Text Available Cedrela odorata L. es una especie que se distingue por la calidad de su madera. El cedro esta - blecido en campo debe adaptarse a cambios en disponibilidad de recursos; la sobrevivivencia es mayor cuando el sistema radical se asocia con microorganismos que mejoran la nutrición y crecimiento. El objetivo del presente trabajo fue evaluar el efecto de Rhizophagus intraradi - ces y Azospirillum brasilense sobre el crecimiento de C. odorata y la capacidad de absorción de nitrógeno (N y fósforo (P. Las semillas de cedro se sembraron en macetas de acuerdo con los siguientes trata - mientos: testigo, fertilización 15 N -15 P -15 K , R. intraradices , A. brasilense , R. intraradices + A. brasilense , y R. intraradices + A. brasilense + fertilización 15 N -15 P -15 K . Las variables morfológicas y fisiológicas de rendimiento y la colonización radical se registraron cada 28 días, y los contenidos de N y P, al final del experimento (140 días. En general, R. intraradices promovió mayor crecimiento vegetal ( P ≤ 0.05 de los componentes morfológicos y fisiológicos del rendimiento. La altura máxima (97 cm se registró en las plantas con R. intraradices + A. brasilense + fertilización 15 N -15 P -15 K , representando 40 % más altura que el testigo. El N y P incrementaron con la inoculación de los microorganismos solos y combinados.

  15. COMPARATIVE EVALUATION OF CONVENTIONAL VERSUS RAPID METHODS FOR AMPLIFIABLE GENOMIC DNA ISOLATION OF CULTURED Azospirillum sp. JG3

    Directory of Open Access Journals (Sweden)

    Stalis Norma Ethica

    2013-12-01

    Full Text Available As an initial attempt to reveal genetic information of Azospirillum sp. JG3 strain, which is still absence despite of the strains' ability in producing valued enzymes, two groups of conventional methods: lysis-enzyme and column-kit; and two rapid methods: thermal disruption and intact colony were evaluated. The aim is to determine the most practical method for obtaining high-grade PCR product using degenerate primers as part of routine-basis protocols for studying the molecular genetics of the Azospirillal bacteria. The evaluation includes the assessment of electrophoresis gel visualization, pellet appearance, preparation time, and PCR result of extracted genomic DNA from each method. Our results confirmed that the conventional methods were more superior to the rapid methods in generating genomic DNA isolates visible on electrophoresis gel. However, modification made in the previously developed DNA isolation protocol giving the simplest and most rapid method of all methods used in this study for extracting PCR-amplifiable DNA of Azospirillum sp. JG3. Intact bacterial cells (intact colony loaded on electrophoresis gel could present genomic DNA band, but could not be completely amplified by PCR without thermal treatment. It can also be inferred from our result that the 3 to 5-min heating in dH2O step is critical for the pre-treatment of colony PCR of Azospirillal cells.

  16. Effects of Azospirillum lipoferum on seedling characteristics derived from sunflower (Helianthus annus L. seed water deficit conditions

    Directory of Open Access Journals (Sweden)

    H. Hadi

    2016-05-01

    Full Text Available Seedling characteristics of different sunflower (Helianthus annus L. cultivars under drought stress and inoculation with the Azospirillum lipoferum in a spilt-factorial layout based on randomized complete block design with three replications were evaluated. Treatments included dehydration stress (seed produced on maternal plants which irrigated after 60 (desirable irrigation, 120 (medium stress, 180 mm (severe stress evaporation from evaporation pan class A, different sunflower cultivars (Lakomka, Master, Favorite, Soor and Armavirosky and inoculation with bacteria (Azospirillum lipoferum and control. Bacteria allocated in the main plots and seeds which derived from dehydration stress conditions and different cultivars were allocated in sub plots as a factorial layout. Results showed that the time of seedling emergence, seedling vigor index, leaf petiole, stem and seedling dry weight were increased 14, 44, 30, 31, 22 and 27 percent by inoculating with bacteria, respectively. The percent of Seedling emergence of seeds derived from medium stress 48 percent was more than optimal irrigation conditions. Final appearance, speed of emergence, emergence index, dry weight and stamina seedling resulting from severe stress conditions were decreased compared with optimal irrigation. Seedling emergence of seeds derived from medium stress which inoculated with bacteria increased by 9 percent. Emergence speed index, appearance, stamina and seedling dry weights of seeds which inoculated with bacteria increased at medium and sever water stress. With consideration of the effect of dehydration stress on germination and seedling emergence, seed inoculation with bacteria improved seedling emergence and seedling vigor of seeds derived from dehydration stress conditions.

  17. Metabolic profiling of two maize (Zea mays L.) inbred lines inoculated with the nitrogen fixing plant-interacting bacteria Herbaspirillum seropedicae and Azospirillum brasilense

    Science.gov (United States)

    Brusamarello-Santos, Liziane Cristina; Gilard, Françoise; Brulé, Lenaïg; Quilleré, Isabelle; Gourion, Benjamin; Ratet, Pascal; Maltempi de Souza, Emanuel; Lea, Peter J.; Hirel, Bertrand

    2017-01-01

    Maize roots can be colonized by free-living atmospheric nitrogen (N2)-fixing bacteria (diazotrophs). However, the agronomic potential of non-symbiotic N2-fixation in such an economically important species as maize, has still not been fully exploited. A preliminary approach to improve our understanding of the mechanisms controlling the establishment of such N2-fixing associations has been developed, using two maize inbred lines exhibiting different physiological characteristics. The bacterial-plant interaction has been characterized by means of a metabolomic approach. Two established model strains of Nif+ diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense and their Nif- couterparts defficient in nitrogenase activity, were used to evaluate the impact of the bacterial inoculation and of N2 fixation on the root and leaf metabolic profiles. The two N2-fixing bacteria have been used to inoculate two genetically distant maize lines (FV252 and FV2), already characterized for their contrasting physiological properties. Using a well-controlled gnotobiotic experimental system that allows inoculation of maize plants with the two diazotrophs in a N-free medium, we demonstrated that both maize lines were efficiently colonized by the two bacterial species. We also showed that in the early stages of plant development, both bacterial strains were able to reduce acetylene, suggesting that they contain functional nitrogenase activity and are able to efficiently fix atmospheric N2 (Fix+). The metabolomic approach allowed the identification of metabolites in the two maize lines that were representative of the N2 fixing plant-bacterial interaction, these included mannitol and to a lesser extend trehalose and isocitrate. Whilst other metabolites such as asparagine, although only exhibiting a small increase in maize roots following bacterial infection, were specific for the two Fix+ bacterial strains, in comparison to their Fix- counterparts. Moreover, a number

  18. Metabolic profiling of two maize (Zea mays L. inbred lines inoculated with the nitrogen fixing plant-interacting bacteria Herbaspirillum seropedicae and Azospirillum brasilense.

    Directory of Open Access Journals (Sweden)

    Liziane Cristina Brusamarello-Santos

    Full Text Available Maize roots can be colonized by free-living atmospheric nitrogen (N2-fixing bacteria (diazotrophs. However, the agronomic potential of non-symbiotic N2-fixation in such an economically important species as maize, has still not been fully exploited. A preliminary approach to improve our understanding of the mechanisms controlling the establishment of such N2-fixing associations has been developed, using two maize inbred lines exhibiting different physiological characteristics. The bacterial-plant interaction has been characterized by means of a metabolomic approach. Two established model strains of Nif+ diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense and their Nif- couterparts defficient in nitrogenase activity, were used to evaluate the impact of the bacterial inoculation and of N2 fixation on the root and leaf metabolic profiles. The two N2-fixing bacteria have been used to inoculate two genetically distant maize lines (FV252 and FV2, already characterized for their contrasting physiological properties. Using a well-controlled gnotobiotic experimental system that allows inoculation of maize plants with the two diazotrophs in a N-free medium, we demonstrated that both maize lines were efficiently colonized by the two bacterial species. We also showed that in the early stages of plant development, both bacterial strains were able to reduce acetylene, suggesting that they contain functional nitrogenase activity and are able to efficiently fix atmospheric N2 (Fix+. The metabolomic approach allowed the identification of metabolites in the two maize lines that were representative of the N2 fixing plant-bacterial interaction, these included mannitol and to a lesser extend trehalose and isocitrate. Whilst other metabolites such as asparagine, although only exhibiting a small increase in maize roots following bacterial infection, were specific for the two Fix+ bacterial strains, in comparison to their Fix- counterparts

  19. Metabolic profiling of two maize (Zea mays L.) inbred lines inoculated with the nitrogen fixing plant-interacting bacteria Herbaspirillum seropedicae and Azospirillum brasilense.

    Science.gov (United States)

    Brusamarello-Santos, Liziane Cristina; Gilard, Françoise; Brulé, Lenaïg; Quilleré, Isabelle; Gourion, Benjamin; Ratet, Pascal; Maltempi de Souza, Emanuel; Lea, Peter J; Hirel, Bertrand

    2017-01-01

    Maize roots can be colonized by free-living atmospheric nitrogen (N2)-fixing bacteria (diazotrophs). However, the agronomic potential of non-symbiotic N2-fixation in such an economically important species as maize, has still not been fully exploited. A preliminary approach to improve our understanding of the mechanisms controlling the establishment of such N2-fixing associations has been developed, using two maize inbred lines exhibiting different physiological characteristics. The bacterial-plant interaction has been characterized by means of a metabolomic approach. Two established model strains of Nif+ diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense and their Nif- couterparts defficient in nitrogenase activity, were used to evaluate the impact of the bacterial inoculation and of N2 fixation on the root and leaf metabolic profiles. The two N2-fixing bacteria have been used to inoculate two genetically distant maize lines (FV252 and FV2), already characterized for their contrasting physiological properties. Using a well-controlled gnotobiotic experimental system that allows inoculation of maize plants with the two diazotrophs in a N-free medium, we demonstrated that both maize lines were efficiently colonized by the two bacterial species. We also showed that in the early stages of plant development, both bacterial strains were able to reduce acetylene, suggesting that they contain functional nitrogenase activity and are able to efficiently fix atmospheric N2 (Fix+). The metabolomic approach allowed the identification of metabolites in the two maize lines that were representative of the N2 fixing plant-bacterial interaction, these included mannitol and to a lesser extend trehalose and isocitrate. Whilst other metabolites such as asparagine, although only exhibiting a small increase in maize roots following bacterial infection, were specific for the two Fix+ bacterial strains, in comparison to their Fix- counterparts. Moreover, a number

  20. (AJST) THE BENEFICIATION OF MUMBWA PHOSPHATE DEPOSIT ...

    African Journals Online (AJOL)

    minerals, heavy media separation using Bromoform and subsequently flotation were applied in the beneficiation tests. ... of pegmatite bodies with high grade P2O5 were discovered by MINEX ..... presence of negatively charged ions such as.

  1. Federal Standard: Beneficial Use of Dredged Material

    Science.gov (United States)

    The purpose of this document is to provide national guidance that explains the role of the Federal Standard in implementing beneficial uses of dredged material from U.S. Army Corps of Engineers’ new and maintenance navigation projects.

  2. Phosphate enhances levan production in the endophytic bacterium Gluconacetobacter diazotrophicus Pal5

    Science.gov (United States)

    Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki

    2014-01-01

    Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production. PMID:24717418

  3. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

    Directory of Open Access Journals (Sweden)

    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.

  4. Structural studies of the polysaccharides from the lipopolysaccharides of Azospirillum brasilense Sp246 and SpBr14.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Grinev, Vyacheslav S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2014-10-29

    Lipopolysaccharides from closely related Azospirillum brasilense strains, Sp246 and SpBr14, were obtained by phenol-water extraction. Mild acid hydrolysis of the lipopolysaccharides followed by GPC on Sephadex G-50 resulted in polysaccharide mixtures. On the basis of sugar and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy data, it was concluded that both bacteria possess the same two distinct polysaccharides having structures 1 and 2: [structure: see text]. Structure 1 has been reported earlier for a polysaccharide of A. brasilense 54 [Fedonenko et al., 2011] whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Effect of Azospirillum brasilense and Burkholderia unamae Bacteria on Maize Photosynthetic Activity Evaluated Using the Photoacoustic Technique

    Science.gov (United States)

    Gordillo-Delgado, F.; Marín, E.; Calderón, A.

    2016-09-01

    In this work, the photosynthetic process of maize plants ( Zea mays), which were grown using seeds inoculated with plant growth promoting bacteria Azospirillum brasilense and Burkholderia unamae, was monitored. Photothermal and photobaric signals obtained by a time-resolved photoacoustic measurement configuration were used for measuring the oxygen evolution rate in situ. A frequency-resolved configuration of the method was utilized to determine the oxygen diffusion coefficient and the thermal diffusivity of the maize leaves. The latter parameters, which can be used as indicators of the photosynthetic activity of maize, are found to vary according to the plant-microbe interaction. Treatment with plant growth promoting bacteria induced a decrease in the oxygen diffusion coefficient of about 20 %.

  6. Mössbauer spectroscopic study of 57Fe metabolic transformations in the rhizobacterium Azospirillum brasilense Sp245

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Kovács, Krisztina; Biró, Borbála; Homonnay, Zoltán; Kuzmann, Ernő

    2014-04-01

    Preliminary 57Fe transmission Mössbauer spectroscopic data were obtained for the first time for live cells of the plant-growth-promoting rhizobacterium Azospirillum brasilense (wild-type strain Sp245) grown aerobically with 57FeIII-nitrilotriacetate (NTA) complex as a sole source of iron. The results obtained have shown that live cells actively reduce part of the assimilated iron(III) to iron(II), the latter amounting up to 33 % of total cellular iron after 18 h of growth, and 48 % after additional 3 days of storage of the dense wet cell suspension in nutrient-free saline solution in air at room temperature (measured at 80 K). The cellular iron(II) was found to be represented by two quadrupole doublets of different high-spin forms, while the parameters of the cellular iron(III) were close to those typical for bacterioferritins.

  7. [Effect of Azospirillum lectins on the Activity of Proteolytic Enzymes and Their Inhibitors in Wheat Seedling Roots].

    Science.gov (United States)

    Alen'kina, S A; Nikitina, V E

    2015-01-01

    The lectins of associative nitrogen-fixing strains Azospirillum brasilense Sp7 and Sp245 were shown to exerte a multidirectional effect on the activity of acidic (pH 3.5), neutral (6.8), and alkaline (pH 7.8) proteinases. The lectin of the epiphytic A. brasilense Sp7 decreased proteolytic activity at all pH values, whereas the lectin of the endophytic A. brasilense Sp245 activated neutral and alkaline proteinases, while not affecting the alkaline ones. Experiments with protease inhibitors made it possible to conclude that the lectins of the studied A. brasilense strains alter the ratio between the activities of different protease types in germinating seeds. The activity of trypsin inhibitors in wheat seedling roots was found to increase in the presence of the lectins. Our results indicate a broader spectrum of effects of azospirilla lectins on the host plant organism.

  8. Nodulation of legumes, nitrogenase activity of roots and occurrence of nitrogen-fixing Azospirillum spp. In representative soils of central Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Sylvester-Bradley, R; De Oliverira, L A; De Podesta Filho, J A; John, T V

    1980-12-01

    Leguminosae do not predominate in the Brazilian Amazon rain forest, although they are among the five best represented families. Plant roots from various soils were examined for the presence of nodules, acetylene-reducing activity and N/sub 2/-fixing Azospirillum spp. Abundant nodulation was found in black earth (''terra preta dos indios'') and in one case on sandy soil under campinarana vegetation along a tributary of the upper Rio Negro. In sandy latosol some nodules occurred in secondary forest and fewer in primary forest. Legumes in disturbed clayey or sandy latosol showed more frequent nodulation. Primary forest on alluvial (''varzea'') soil, and in Bahia coastal rain forest on sandy latosol and Erythrina glauca used for shading cacao plantations were abundantly nodulated. Acetylene reduction assays showed no, or very little, nitrogenase activity of roots from primary or secondary forest on clayey latosol near Manaus. Nodulated roots from secondary forest on sandy latosol showed acetylene-reducing activity. High rates of acetylene reduction were observed in nodulated roots of primary forest on alluvial ''varzea'' soil. Root samples showed ethylene absorption in controls without acetylene which might interfere with the results of acetylene reduction tests. The incidence of Azospirillum was also higher in black earth than the other soils examined, and in soils with higher pH. The hypothesis that Azospirillum is associated with Trema micantha roots was refuted. Roots and soils collected under cultivated grasses showed a higher incidence of Azospirillum when fertilized with phosphorus and lime. Results indicate that nitrogen fixation did occur in association with roots in some soils, but not with roots of primary or secondary forest on clayey latosol in the vicinity of Manaus, which is the most common soil in Central Amazonia. The possible reasons for this are discussed.

  9. Identification and Isolation of Genes Involved in Poly(β-Hydroxybutyrate) Biosynthesis in Azospirillum brasilense and Characterization of a phbC Mutant

    OpenAIRE

    Kadouri, Daniel; Burdman, Saul; Jurkevitch, Edouard; Okon, Yaacov

    2002-01-01

    Like many other prokaryotes, rhizobacteria of the genus Azospirillum produce high levels of poly(β-hydroxybutyrate) (PHB) under suboptimal growth conditions. Utilization of PHB by bacteria under stress has been proposed as a mechanism that favors their compatible establishment in competitive environments, thus showing great potential for the improvement of bacterial inoculants for plants and soils. The three genes that are considered to be essential in the PHB biosynthetic pathway, phbA (β-ke...

  10. Enzyme Production and Nitrogen Fixation by Free, Immobilized and Coimmobilized Inoculants of Trichoderma harzianum and Azospirillum brasilense and Their Possible Role in Growth Promotion of Tomato

    Directory of Open Access Journals (Sweden)

    Momein H. El-Katatny

    2010-01-01

    Full Text Available A plant growth-promoting rhizobacterium (Azospirillum brasilense strain Az and a biocontrol fungus (Trichoderma harzianum strain T24 have been evaluated for their individual and combined production of hydrolytic enzymes, nitrogen fixation and their possible role in growth promotion of tomato seedlings. The studied organisms were inoculated as free or calcium alginate-encapsulated cells. All freshly prepared macrobeads showed high encapsulation capacity (EC/% of inocula compared with dry macrobeads. Results of enzyme production did not exhibit consistent pattern of the effect of encapsulation process on enzyme production. Beads entrapping bacterial and/or fungal cells were used successfully in 3 repeated cycles in the presence of fresh sterile culture medium in each growth cycle. Enzyme production by immobilized bacterial and/or fungal cells increased as the growth cycles were repeated. Co-culturing of A. brasilense with T. harzianum (free or immobilized in semisolid nitrogen deficient medium (N-free medium enabled A. brasilense to fix nitrogen on pectin, chitin and carboxymethyl cellulose. The activity of nitrogen fixation by A. brasilense in the case of single and combined cultures with Trichoderma (using dry encapsulated beads into the sterile soil increased with the addition of carbon source. Most of inoculations with free or alginate macrobead formulations of T. harzianum and/or A. brasilense showed significant increase in the growth parameters of tomato seedlings. The root system grew more profusely in the case of all seeds treated with A. brasilense. The growth parameters of Az/T24-treated seeds using dry coimmobilized macrobeads were higher than those of the untreated control. Moreover, the effect was improved significantly in soil enriched with different C sources. Enhanced tomato seedling growth after the co-inoculation could be due to the synergistic effect of both Trichoderma and Azospirillum. Finally, co-inoculation with Azospirillum

  11. Frequent beneficial mutations during single-colony serial transfer of Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Kathleen E Stevens

    2011-08-01

    Full Text Available The appearance of new mutations within a population provides the raw material for evolution. The consistent decline in fitness observed in classical mutation accumulation studies has provided support for the long-held view that deleterious mutations are more common than beneficial mutations. Here we present results of a study using a mutation accumulation design with the bacterium Streptococcus pneumoniae in which the fitness of the derived populations increased. This rise in fitness was associated specifically with adaptation to survival during brief stationary phase periods between single-colony population bottlenecks. To understand better the population dynamics behind this unanticipated adaptation, we developed a maximum likelihood model describing the processes of mutation and stationary-phase selection in the context of frequent population bottlenecks. Using this model, we estimate that the rate of beneficial mutations may be as high as 4.8×10(-4 events per genome for each time interval corresponding to the pneumococcal generation time. This rate is several orders of magnitude higher than earlier estimates of beneficial mutation rates in bacteria but supports recent results obtained through the propagation of small populations of Escherichia coli. Our findings indicate that beneficial mutations may be relatively frequent in bacteria and suggest that in S. pneumoniae, which develops natural competence for transformation, a steady supply of such mutations may be available for sampling by recombination.

  12. Assessment of SCAR markers to design real-time PCR primers for rhizosphere quantification of Azospirillum brasilense phytostimulatory inoculants of maize.

    Science.gov (United States)

    Couillerot, O; Poirier, M-A; Prigent-Combaret, C; Mavingui, P; Caballero-Mellado, J; Moënne-Loccoz, Y

    2010-08-01

    To assess the applicability of sequence characterized amplified region (SCAR) markers obtained from BOX, ERIC and RAPD fragments to design primers for real-time PCR quantification of the phytostimulatory maize inoculants Azospirillum brasilense UAP-154 and CFN-535 in the rhizosphere. Primers were designed based on strain-specific SCAR markers and were screened for successful amplification of target strain and absence of cross-reaction with other Azospirillum strains. The specificity of primers thus selected was verified under real-time PCR conditions using genomic DNA from strain collection and DNA from rhizosphere samples. The detection limit was 60 fg DNA with pure cultures and 4 x 10(3) (for UAP-154) and 4 x 10(4) CFU g(-1) (for CFN-535) in the maize rhizosphere. Inoculant quantification was effective from 10(4) to 10(8) CFU g(-1) soil. BOX-based SCAR markers were useful to find primers for strain-specific real-time PCR quantification of each A. brasilense inoculant in the maize rhizosphere. Effective root colonization is a prerequisite for successful Azospirillum phytostimulation, but cultivation-independent monitoring methods were lacking. The real-time PCR methods developed here will help understand the effect of environmental conditions on root colonization and phytostimulation by A. brasilense UAP-154 and CFN-535.

  13. Interspecific cooperation: enhanced growth, attachment and strain-specific distribution in biofilms through Azospirillum brasilense-Pseudomonas protegens co-cultivation.

    Science.gov (United States)

    Pagnussat, Luciana A; Salcedo, Florencia; Maroniche, Guillermo; Keel, Christoph; Valverde, Claudio; Creus, Cecilia M

    2016-10-01

    Plant-growth-promoting bacteria belonging to Azospirillum and Pseudomonas genera are major inhabitants of the rhizosphere. Both are increasingly commercialized as crops inoculants. Interspecific interaction in the rhizosphere is critical for inoculants aptness. The objective of this work was to evaluate Azospirillum and Pseudomonas interaction in mixed biofilms by co-cultivation of the model strains Azospirillum brasilense Sp245 and Pseudomonas protegens CHA0. The results revealed enhanced growth of both strains when co-cultured in static conditions. Moreover, Sp245 biofilm formed in plastic surfaces was increased 2-fold in the presence of CHA0. Confocal microscopy revealed highly structured mixed biofilms showing Sp245 mainly on the bottom and CHA0 towards the biofilm surface. In addition, A. brasilense biofilm was thicker and denser when co-cultured with P. protegens. In a colony-colony interaction assay, Sp245 changed nearby CHA0 producing small colony phenotype, which accounts for a diffusible metabolite mediator; though CHA0 spent medium did not affect Sp245 colony phenotype. Altogether, these results point to a cooperative interaction between A. brasilense Sp245 and P. protegens CHA0 in which both strains increase their static growth and produce structured mixed biofilms with a strain-specific distribution. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. [Prebiotics: concept, properties and beneficial effects].

    Science.gov (United States)

    Corzo, N; Alonso, J L; Azpiroz, F; Calvo, M A; Cirici, M; Leis, R; Lombó, F; Mateos-Aparicio, I; Plou, F J; Ruas-Madiedo, P; Rúperez, P; Redondo-Cuenca, A; Sanz, M L; Clemente, A

    2015-02-07

    Prebiotics are non-digestible food ingredients (oligosaccharides) that reach the colon and are used as substrate by microorganisms producing energy, metabolites and micronutrients used for the host; in addition they also stimulate the selective growth of certain beneficial species (mainly bifidobacteria and lactobacilli) in the intestinal microbiota. In this article, a multidisciplinary approach to understand the concept of prebiotic carbohydrates, their properties and beneficial effects in humans has been carried out. Definitions of prebiotics, reported by relevant international organizations and researchers, are described. A comprehensive description of accepted prebiotics having strong scientific evidence of their beneficial properties in humans (inulin-type fructans, FOS, GOS, lactulose and human milk oligosaccharides) is reported. Emerging prebiotics and those which are in the early stages of study have also included in this study. Taken into account that the chemical structure greatly influences carbohydrates prebiotic properties, the analytical techniques used for their analysis and characterization are discussed. In vitro and in vivo models used to evaluate the gastrointestinal digestion, absorption resistance and fermentability in the colon of prebiotics as well as major criteria to design robust intervention trials in humans are described. Finally, a comprehensive summary of the beneficial effects of prebiotics for health at systemic and intestinal levels is reported. The research effort on prebiotics has been intensive in last decades and has demonstrated that a multidisciplinary approach is necessary in order to claim their health benefits. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  15. Rare beneficial mutations can halt Muller's ratchet

    Science.gov (United States)

    Balick, Daniel; Goyal, Sidhartha; Jerison, Elizabeth; Neher, Richard; Shraiman, Boris; Desai, Michael

    2012-02-01

    In viral, bacterial, and other asexual populations, the vast majority of non-neutral mutations are deleterious. This motivates the application of models without beneficial mutations. Here we show that the presence of surprisingly few compensatory mutations halts fitness decay in these models. Production of deleterious mutations is balanced by purifying selection, stabilizing the fitness distribution. However, stochastic vanishing of fitness classes can lead to slow fitness decay (i.e. Muller's ratchet). For weakly deleterious mutations, production overwhelms purification, rapidly decreasing population fitness. We show that when beneficial mutations are introduced, a stable steady state emerges in the form of a dynamic mutation-selection balance. We argue this state is generic for all mutation rates and population sizes, and is reached as an end state as genomes become saturated by either beneficial or deleterious mutations. Assuming all mutations have the same magnitude selective effect, we calculate the fraction of beneficial mutations necessary to maintain the dynamic balance. This may explain the unexpected maintenance of asexual genomes, as in mitochondria, in the presence of selection. This will affect in the statistics of genetic diversity in these populations.

  16. Fluidized bed dry dense medium coal beneficiation

    CSIR Research Space (South Africa)

    North, Brian C

    2017-10-01

    Full Text Available medium beneficiation using a fluidized bed was investigated. Bed materials of sand, magnetite and ilmenite were used in a laboratory sized cylindrical fluidized bed. The materials were individually tested, as were mixes of sand and heavy minerals. Coal...

  17. Agrobacterium tumefaciens is a diazotrophic bacterium

    International Nuclear Information System (INIS)

    Kanvinde, L.; Sastry, G.R.K.

    1990-01-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grown on nitrogen-free medium, reduce acetylene to ethylene, and incorporate 15 N supplied as 15 N 2 . As with most other well-characterized diazotrophic bacteria, the presence of NH 4 + in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship

  18. Agrobacterium tumefaciens is a diazotrophic bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Kanvinde, L.; Sastry, G.R.K. (Univ. of Leeds (England))

    1990-07-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grown on nitrogen-free medium, reduce acetylene to ethylene, and incorporate {sup 15}N supplied as {sup 15}N{sub 2}. As with most other well-characterized diazotrophic bacteria, the presence of NH{sub 4}{sup +} in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship.

  19. The chemical formula of a magnetotactic bacterium.

    Science.gov (United States)

    Naresh, Mohit; Das, Sayoni; Mishra, Prashant; Mittal, Aditya

    2012-05-01

    Elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. Treatment of microbial cells explicitly as a "chemical" species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. Application of mass and energy balances on living cells has proved to be useful in modeling of bioengineering systems, particularly in deriving optimized media compositions for growing microorganisms to maximize yields of desired bio-derived products by regulating intra-cellular metabolic networks. In this work, application of elemental mass balance during growth of Magnetospirillum gryphiswaldense in bioreactors has resulted in the discovery of the chemical formula of the magnetotactic bacterium. By developing a stoichiometric equation characterizing the formation of a magnetotactic bacterial cell, coupled with rigorous experimental measurements and robust calculations, we report the elemental formula of M. gryphiswaldense cell as CH(2.06)O(0.13)N(0.28)Fe(1.74×10(-3)). Remarkably, we find that iron metabolism during growth of this magnetotactic bacterium is much more correlated individually with carbon and nitrogen, compared to carbon and nitrogen with each other, indicating that iron serves more as a nutrient during bacterial growth rather than just a mineral. Magnetotactic bacteria have not only invoked some interest in the field of astrobiology for the last two decades, but are also prokaryotes having the unique ability of synthesizing membrane bound intracellular organelles. Our findings on these unique prokaryotes are a strong addition to the limited repertoire, of elemental compositions of living cells, aimed at exploring the chemical logic of life. Copyright © 2011 Wiley Periodicals, Inc.

  20. Desempenho agronômico a campo de híbridos de milho inoculados com Azospirillum

    Directory of Open Access Journals (Sweden)

    Patricia Dörr de Quadros

    2014-04-01

    Full Text Available O uso de inoculantes na cultura do milho tem sido cada vez mais valorizado, em vista dos benefícios que pode trazer à cultura, como a fixação biológica do nitrogênio e o aumento da quantidade de raízes. Isto pode melhorar a absorção de água e nutrientes pela planta, contribuindo para o desenvolvimento do milho, principalmente em períodos de seca. Este estudo foi desenvolvido com o objetivo de avaliar, em condições de campo, as características agronômicas e o rendimento de grãos de híbridos de milho, inoculados, ou não, com uma mistura de três espécies de Azospirillum (A. brasilense, A. lipoferum, A. oryzae. Foram avaliados o teor relativo de clorofila nas folhas, a altura de planta, a senescência foliar, os componentes de rendimento de grãos, o teor de N, a matéria seca da parte aérea das plantas e o número mais provável de bactérias diazotróficas na rizosfera das plantas. A inoculação manteve o teor de clorofila significativamente maior até o estádio R3 das plantas, para os três híbridos testados, aumentou o rendimento da matéria seca da parte aérea, dos híbridos AS 1575 e SHS 5050, o peso de 1000 grãos, para o híbrido P32R48 e altura, para o AS 1575. Houve interação entre os genótipos de milho e as bactérias inoculadas, visto que, cada híbrido testado respondeu de forma diferente à inoculação. A inoculação de Azospirillum em milho demonstrou estimular o desenvolvimento das plantas no período vegetativo, aumentando a probabilidade de obter-se um estande de plantas uniforme, maior resistência ao estresse e maior concentração de clorofila nas folhas.

  1. Beneficial properties of probiotic yeast Saccharomyces boulardii

    OpenAIRE

    Tomičić Zorica M.; Čolović Radmilo R.; Čabarkapa Ivana S.; Vukmirović Đuro M.; Đuragić Olivera M.; Tomičić Ružica M.

    2016-01-01

    Saccharomyces boulardii is unique probiotic and biotherapeutic yeast, known to survive in gastric acidity and it is not adversely affected or inhibited by antibiotics or does not alter or adversely affect the normal microbiota. S. boulardii has been utilized worldwide as a probiotic supplement to support gastrointestinal health. The multiple mechanisms of action of S. boulardii and its properties may explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases th...

  2. The chemotaxis-like Che1 pathway has an indirect role in adhesive cell properties of Azospirillum brasilense.

    Science.gov (United States)

    Siuti, Piro; Green, Calvin; Edwards, Amanda Nicole; Doktycz, Mitchel J; Alexandre, Gladys

    2011-10-01

    The Azospirillum brasilense chemotaxis-like Che1 signal transduction pathway was recently shown to modulate changes in adhesive cell surface properties that, in turn, affect cell-to-cell aggregation and flocculation behaviors rather than flagellar-mediated chemotaxis. Attachment to surfaces and root colonization may be functions related to flocculation. Here, the conditions under which A. brasilense wild-type Sp7 and che1 mutant strains attach to abiotic and biotic surfaces were examined using in vitro attachment and biofilm assays combined with atomic force microscopy and confocal microscopy. The nitrogen source available for growth is found to be a major modulator of surface attachment by A. brasilense and could be promoted in vitro by lectins, suggesting that it depends on interaction with surface-exposed residues within the extracellular matrix of cells. However, Che1-dependent signaling is shown to contribute indirectly to surface attachment, indicating that distinct mechanisms are likely underlying flocculation and attachment to surfaces in A. brasilense. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Structure and thermodynamics of effector molecule binding to the nitrogen signal transduction PII protein GlnZ from Azospirillum brasilense.

    Science.gov (United States)

    Truan, Daphné; Bjelić, Saša; Li, Xiao-Dan; Winkler, Fritz K

    2014-07-29

    The trimeric PII signal transduction proteins regulate the function of a variety of target proteins predominantly involved in nitrogen metabolism. ATP, ADP and 2-oxoglutarate (2-OG) are key effector molecules influencing PII binding to targets. Studies of PII proteins have established that the 20-residue T-loop plays a central role in effector sensing and target binding. However, the specific effects of effector binding on T-loop conformation have remained poorly documented. We present eight crystal structures of the Azospirillum brasilense PII protein GlnZ, six of which are cocrystallized and liganded with ADP or ATP. We find that interaction with the diphosphate moiety of bound ADP constrains the N-terminal part of the T-loop in a characteristic way that is maintained in ADP-promoted complexes with target proteins. In contrast, the interactions with the triphosphate moiety in ATP complexes are much more variable and no single predominant interaction mode is apparent except for the ternary MgATP/2-OG complex. These conclusions can be extended to most investigated PII proteins of the GlnB/GlnK subfamily. Unlike reported for other PII proteins, microcalorimetry reveals no cooperativity between the three binding sites of GlnZ trimers for any of the three effectors under carefully controlled experimental conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Bacteriophytochrome controls carotenoid-independent response to photodynamic stress in a non-photosynthetic rhizobacterium, Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kumar, Santosh; Kateriya, Suneel; Singh, Vijay Shankar; Tanwar, Meenakshi; Agarwal, Shweta; Singh, Hina; Khurana, Jitendra Paul; Amla, Devinder Vijay; Tripathi, Anil Kumar

    2012-01-01

    Ever since the discovery of the role of bacteriophytochrome (BphP) in inducing carotenoid synthesis in Deinococcus radiodurans in response to light the role of BphPs in other non-photosynthetic bacteria is not clear yet. Azospirillum brasilense, a non-photosynthetic rhizobacterium, harbours a pair of BphPs out of which AbBphP1 is a homolog of AtBphP1 of Agrobacterium tumefaciens. By overexpression, purification, biochemical and spectral characterization we have shown that AbBphP1 is a photochromic bacteriophytochrome. Phenotypic study of the ΔAbBphP1 mutant showed that it is required for the survival of A. brasilense on minimal medium under red light. The mutant also showed reduced chemotaxis towards dicarboxylates and increased sensitivity to the photooxidative stress. Unlike D. radiodurans, AbBphP1 was not involved in controlling carotenoid synthesis. Proteome analysis of the ΔAbBphP1 indicated that AbBphP1 is involved in inducing a cellular response that enables A. brasilense in regenerating proteins that might be damaged due to photodynamic stress.

  5. cDNA-AFLP analysis of differential gene expression related to cell chemotactic and encystment of Azospirillum brasilense.

    Science.gov (United States)

    Li, Huamin; Cui, Yanhua; Wu, Lixian; Tu, Ran; Chen, Sanfeng

    2011-12-20

    Our previous study indicated org35 was involved in chemotaxis and interacted with nitrogen fixation transcriptional activator NifA via PAS domain. In order to reveal the role of org35 in nitrogen regulation, the downstream target genes of org35 were identified. We here report differentially expressed genes in org35 mutants comparing with wild type Sp7 by means of cDNA-AFLP. Four up-regulated transcript-derived fragments (TDFs) homologues of chemotaxis transduction proteins were found, including CheW, methyl-accepting chemotaxis protein and response regulator CheY-like receiver. Three distinct TDFs (AB46, AB58 and AB63) were similar to PHB de-polymerase C-terminus, cell shape-determining protein and flagellin domain protein. And 11 TDFs showed similarities with signal transduction proteins, including homologous protein of the nitrogen regulation protein NtrY and nitrate/nitrite response regulator protein NarL. These data suggested that the Azospirillum brasilense org35 was a multi-effecter and involved in chemotaxis, cyst development and regulation of nitrogen fixation. Copyright © 2010 Elsevier GmbH. All rights reserved.

  6. Beneficial effects of cytokine induced hyperlipidemia.

    Science.gov (United States)

    Feingold, K R; Hardardóttir, I; Grunfeld, C

    1998-01-01

    Infection, inflammation and trauma induce marked changes in the plasma levels of a wide variety of proteins (acute phase response), and these changes are mediated by cytokines. The acute phase response is thought to be beneficial to the host. The host's response to injury also results in dramatic alterations in lipid metabolism and circulating lipoprotein levels which are mediated by cytokines. A large number of cytokines including TNF, the interleukins, and the interferons increase serum triglyceride levels. This rapid increase (1-2 h) is predominantly due to an increase in hepatic VLDL secretion while the late increase may be due to a variety of factors including increased hepatic production of VLDL or delayed clearance secondary to a decrease in lipoprotein lipase activity and/or apolipoprotein E levels on VLDL. In animals other than primates, cytokines also increase serum cholesterol levels, most likely by increasing hepatic cholesterol. Cytokines increase hepatic cholesterol synthesis by stimulating HMG CoA reductase gene expression and decrease hepatic cholesterol catabolism by inhibiting cholesterol 7 alpha-hydroxylase, the key enzyme in bile acid synthesis. Injury and/or cytokines also decrease HDL cholesterol levels and induce alterations in the composition of HDL. The content of SAA and apolipoprotein J increase, apolipoprotein A1 may decrease, and the cholesterol ester content decreases while free cholesterol increases. Additionally, key proteins involved in HDL metabolism are altered by cytokines; LCAT activity, hepatic lipase activity, and CETP levels decrease. These changes in lipid and lipoprotein metabolism may be beneficial in a number of ways including: lipoproteins competing with viruses for cellular receptors, apolipoproteins neutralizing viruses, lipoproteins binding and targeting parasites for destruction, apolipoproteins lysing parasites, redistribution of nutrients to cells involved in the immune response and/or tissue repair, and

  7. Fernald scrap metal recycling and beneficial reuse

    International Nuclear Information System (INIS)

    Motl, G.P.; Burns, D.D.

    1993-10-01

    The Fernald site, formerly the Feed Materials Production Facility, produced uranium metal products to meet defense production requirements for the Department of Energy from 1953 to 1989. In this report is is described how the Fernald scrap metal project has demonstrated that contractor capabilities can be used successfully to recycle large quantities of Department of Energy scrap metal. The project has proven that the open-quotes beneficial reuseclose quotes concept makes excellent economic sense when a market for recycled products can be identified. Topics covered in this report include the scrap metal pile history, the procurement strategy, scrap metal processing, and a discussion of lessons learned

  8. Genome-wide identification of microRNA and siRNA responsive to endophytic beneficial diazotrophic bacteria in maize.

    Science.gov (United States)

    Thiebaut, Flávia; Rojas, Cristian A; Grativol, Clícia; Motta, Mariana Romeiro; Vieira, Tauan; Regulski, Michael; Martienssen, Robert A; Farinelli, Laurent; Hemerly, Adriana S; Ferreira, Paulo C G

    2014-09-06

    Small RNA (sRNA) has been described as a regulator of gene expression. In order to understand the role of maize sRNA (Zea mays-hybrid UENF 506-8) during association with endophytic nitrogen-fixing bacteria, we analyzed the sRNA regulated by its association with two diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense. Deep sequencing analysis was done with RNA extracted from plants inoculated with H. seropedicae, allowing the identification of miRNA and siRNA. A total of 25 conserved miRNA families and 15 novel miRNAs were identified. A dynamic regulation in response to inoculation was also observed. A hypothetical model involving copper-miRNA is proposed, emphasizing the fact that the up-regulation of miR397, miR398, miR408 and miR528, which is followed by inhibition of their targets, can facilitate association with diazotrophic bacteria. Similar expression patterns were observed in samples inoculated with A. brasilense. Moreover, novel miRNA and siRNA were classified in the Transposable Elements (TE) database, and an enrichment of siRNA aligned with TE was observed in the inoculated samples. In addition, an increase in 24-nt siRNA mapping to genes was observed, which was correlated with an increase in methylation of the coding regions and a subsequent reduction in transcription. Our results show that maize has RNA-based silencing mechanisms that can trigger specific responses when plants interact with beneficial endophytic diazotrophic bacteria. Our findings suggest important roles for sRNA regulation in maize, and probably in other plants, during association with diazotrophic bacteria, emphasizing the up-regulation of Cu-miRNA.

  9. Ethanologenic potential of the bacterium Bacillus cereus NB-19 in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-01

    Dec 1, 2009 ... Ethanologenic bacterium was cultivated in a suspension of sugarcane ... bagasse is very useful for obtaining yields of the different products including cell mass and ethanol as ... the resources for the green fuel generation.

  10. Beneficial utilization of nuclear waste products

    International Nuclear Information System (INIS)

    Dix, G.P.

    1975-01-01

    A sufficient supply of isotopes exists to conduct demonstrational experiments in the 1975-1980 time frame to stimulate a market for waste products. A large potential market exists for a number of waste products, measured in terms of billions of dollars. Actinide by-products can become a feed stock for producing other energy producing isotopes by neutron irradiation whose value may exceed that of the fission products. Commercial reprocessors will not invest in the extraction and separation of isotopes from the waste stream until a proven market has evolved. Economic studies must be performed to establish the trade-offs between the beneficial use or disposal of wastes. Fundamental to these studies are process economics, safety analyses applications studies, and market analyses, both domestic and foreign. Regardless of the degree of beneficial utilization of wastes, some residual material from wastes not utilized and spent by-products after utilization will have to undergo ultimate disposal. Isotopic waste products have the potential for solving a number of societal and national security problems and represent a unique source of energy and materials

  11. SRS stainless steel beneficial reuse program

    Energy Technology Data Exchange (ETDEWEB)

    Boettinger, W.L.

    1997-02-01

    The US Department of Energy`s (DOE) Savannah River Site (SRS) has thousands of tons of stainless steel radioactive scrap metal (RSNI). Much of the metal is volumetrically contaminated. There is no {open_quotes}de minimis{close_quotes} free release level for volumetric material, and therefore no way to recycle the metal into the normal commercial market. If declared waste, the metal would qualify as low level radioactive waste (LLW) and ultimately be dispositioned through shallow land buried at a cost of millions of dollars. The metal however could be recycled in a {open_quotes}controlled release{close_quote} manner, in the form of containers to hold other types of radioactive waste. This form of recycle is generally referred to as {open_quotes}Beneficial Reuse{close_quotes}. Beneficial reuse reduces the amount of disposal space needed and reduces the need for virgin containers which would themselves become contaminated. Stainless steel is particularly suited for long term storage because of its resistance to corrosion. To assess the practicality of stainless steel RSM recycle the SRS Benficial Reuse Program began a demonstration in 1994, funded by the DOE Office of Science and Technology. This paper discusses the experiences gained in this program.

  12. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  13. Residual effect of nitrogen fertilization and Azospirillum brasilense inoculation in the maize cultureEfeito residual da adubação nitrogenada e inoculação de Azospirillum brasilense na cultura do milho

    Directory of Open Access Journals (Sweden)

    Jackson Huzar Novakowiski

    2011-12-01

    Full Text Available The diazotrophic bacteria Azospirillum brasilense is an organism able to fix nitrogen of atmosphere and produce plant hormones. Nevertheless, there is lack of information with regard to use in field conditions, especially in production systems that have presence of animals in a determined year period. The objective of paper was to evaluate the association of the nitrogen residual effect of fertilization in pasture winter and the inoculation with A. brasilense in the maize culture. Were carried two experiments in Guarapuava (PR in season 2008/09 with randomized block design with split plots in three replication. The main parcel consisted of application 5 levels of N (0, 75, 150, 225 e 300 kg ha-1 in pasture of black oat and ryegrass occupied by bovines and 4 treatments in the maize (T1 = control; T2 = inoculation of A. brasilense; T3 = 75 kg ha-1 of N; T4 = 150 kg ha-1 of N. Were evaluated: plants population, ears per plant, productivity, mass thousand grains, damage grains, row per ear and grains per row. There was residual effect of nitrogen applied in the pasture on maize culture. The mass thousand grains and the number of rows per ear of maize presented quadratic response for increase of nitrogen level in the pasture. The inoculation of A. brasilense provided higher productivity than control same with increase the nitrogen level applied in the pasture, with quadratic response in the experiment 1 and linear in the experiment 2.A bactéria diazotrófica Azospirillum brasilense é um organismo capaz de fixar nitrogênio da atmosfera e produzir hormônios vegetais. No entanto, há carência de informações a respeito de seu uso em condições de campo, sobretudo em sistemas de produção que tem a presença de animais em um determinado período do ano. O objetivo do trabalho foi avaliar a associação do efeito residual da adubação nitrogenada na pastagem de inverno e a inoculação de A. brasilense na cultura do milho. Foram conduzidos dois

  14. Antioxidants keep the potentially probiotic but highly oxygen-sensitive human gut bacterium Faecalibacterium prausnitzii alive at ambient air.

    Directory of Open Access Journals (Sweden)

    M Tanweer Khan

    Full Text Available The beneficial human gut microbe Faecalibacterium prausnitzii is a 'probiotic of the future' since it produces high amounts of butyrate and anti-inflammatory compounds. However, this bacterium is highly oxygen-senstive, making it notoriously difficult to cultivate and preserve. This has so far precluded its clinical application in the treatment of patients with inflammatory bowel diseases. The present studies were therefore aimed at developing a strategy to keep F. prausnitzii alive at ambient air. Our previous research showed that F. prausnitzii can survive in moderately oxygenized environments like the gut mucosa by transfer of electrons to oxygen. For this purpose, the bacterium exploits extracellular antioxidants, such as riboflavin and cysteine, that are abundantly present in the gut. We therefore tested to what extent these antioxidants can sustain the viability of F. prausnitzii at ambient air. The present results show that cysteine can facilitate the survival of F. prausnitzii upon exposure to air, and that this effect is significantly enhanced the by addition of riboflavin and the cryoprotectant inulin. The highly oxygen-sensitive gut bacterium F. prausnitzii can be kept alive at ambient air for 24 h when formulated with the antioxidants cysteine and riboflavin plus the cryoprotectant inulin. Improved formulations were obtained by addition of the bulking agents corn starch and wheat bran. Our present findings pave the way towards the biomedical exploitation of F. prausnitzii in redox-based therapeutics for treatment of dysbiosis-related inflammatory disorders of the human gut.

  15. [Beneficial effects of chocolate on cardiovascular health].

    Science.gov (United States)

    Gómez-Juaristi, M; González-Torres, L; Bravo, L; Vaquero, M P; Bastida, S; Sánchez-Muniz, F J

    2011-01-01

    Since ancient times, numerous health beneficial effects have been attributed to chocolate, closing up its consumption to a therapeutic use. The present study reviews some relevant studies about chocolate (and its bioactive compounds) on some cardiovascular risk factors and stresses the need of future studies. The consumption of cocoa/ chocolate (i) increases plasma antioxidant capacity, (ii) diminishes platelet function and inflammation, and (iii) decreases diastolic and systolic arterial pressures. Data currently available indicate that daily consumption of cocoa-rich chocolate (rich in polyphenols) may at least partially lower cardiovascular disease risk. Further studies are required in order to establish the bioavailability and mechanisms of action of bioactive compounds in chocolate. The study of the interaction of chocolate and its components with candidate genes will also supply necessary information regarding the individuals best suited to benefit from a potential cardiovascular disease treatment with chocolate.

  16. Electrostatic Separator for Beneficiation of Lunar Soil

    Science.gov (United States)

    Quinn, Jacqueline; Arens, Ellen; Trigwell, Steve; Captain, James

    2010-01-01

    A charge separator has been constructed for use in a lunar environment that will allow for separation of minerals from lunar soil. In the present experiments, whole lunar dust as received was used. The approach taken here was that beneficiation of ores into an industrial feedstock grade may be more efficient. Refinement or enrichment of specific minerals in the soil before it is chemically processed may be more desirable as it would reduce the size and energy requirements necessary to produce the virgin material, and it may significantly reduce the process complexity. The principle is that minerals of different composition and work function will charge differently when tribocharged against different materials, and hence be separated in an electric field.

  17. Beneficial properties of probiotic yeast Saccharomyces boulardii

    Directory of Open Access Journals (Sweden)

    Tomičić Zorica M.

    2016-01-01

    Full Text Available Saccharomyces boulardii is unique probiotic and biotherapeutic yeast, known to survive in gastric acidity and it is not adversely affected or inhibited by antibiotics or does not alter or adversely affect the normal microbiota. S. boulardii has been utilized worldwide as a probiotic supplement to support gastrointestinal health. The multiple mechanisms of action of S. boulardii and its properties may explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases that have been confirmed by clinical trials. Caution should be taken in patients with risk factors for adverse events. Its potential application in various dairy foods could offer an alternative probiotic product to people suffering from antibiotic-associated diarrhea. This review discusses the evidence for efficacy and safety of S. boulardii as a probiotic for the prevention and therapy of gastrointestinal disorders in humans.

  18. Produced Water Management and Beneficial Use

    International Nuclear Information System (INIS)

    Brown, Terry; Frost, Carol; Hayes, Thomas; Heath, Leo; Johnson, Drew; Lopez, David; Saffer, Demian; Urynowicz, Michael; Wheaton, John; Zoback, Mark

    2007-01-01

    Large quantities of water are associated with the production of coalbed methane (CBM) in the Powder River Basin (PRB) of Wyoming. The chemistry of co-produced water often makes it unsuitable for subsequent uses such as irrigated agriculture. However, co-produced waters have substantial potential for a variety of beneficial uses. Achieving this potential requires the development of appropriate water management strategies. There are several unique characteristics of co-produced water that make development of such management strategies a challenge. The production of CBM water follows an inverse pattern compared to traditional wells. CBM wells need to maintain low reservoir pressures to promote gas production. This need renders the reinjection of co-produced waters counterproductive. The unique water chemistry of co-produced water can reduce soil permeability, making surface disposal difficult. Unlike traditional petroleum operations where co-produced water is an undesirable by-product, co-produced water in the PRB often is potable, making it a highly valued resource in arid western states. This research project developed and evaluated a number of water management options potentially available to CBM operators. These options, which focus on cost-effective and environmentally-sound practices, fall into five topic areas: Minimization of Produced Water, Surface Disposal, Beneficial Use, Disposal by Injection and Water Treatment. The research project was managed by the Colorado Energy Research Institute (CERI) at the Colorado School of Mines (CSM) and involved personnel located at CERI, CSM, Stanford University, Pennsylvania State University, the University of Wyoming, the Argonne National Laboratory, the Gas Technology Institute, the Montana Bureau of Mining and Geology and PVES Inc., a private firm

  19. Produced Water Management and Beneficial Use

    Energy Technology Data Exchange (ETDEWEB)

    Terry Brown; Carol Frost; Thomas Hayes; Leo Heath; Drew Johnson; David Lopez; Demian Saffer; Michael Urynowicz; John Wheaton; Mark Zoback

    2007-10-31

    Large quantities of water are associated with the production of coalbed methane (CBM) in the Powder River Basin (PRB) of Wyoming. The chemistry of co-produced water often makes it unsuitable for subsequent uses such as irrigated agriculture. However, co-produced waters have substantial potential for a variety of beneficial uses. Achieving this potential requires the development of appropriate water management strategies. There are several unique characteristics of co-produced water that make development of such management strategies a challenge. The production of CBM water follows an inverse pattern compared to traditional wells. CBM wells need to maintain low reservoir pressures to promote gas production. This need renders the reinjection of co-produced waters counterproductive. The unique water chemistry of co-produced water can reduce soil permeability, making surface disposal difficult. Unlike traditional petroleum operations where co-produced water is an undesirable by-product, co-produced water in the PRB often is potable, making it a highly valued resource in arid western states. This research project developed and evaluated a number of water management options potentially available to CBM operators. These options, which focus on cost-effective and environmentally-sound practices, fall into five topic areas: Minimization of Produced Water, Surface Disposal, Beneficial Use, Disposal by Injection and Water Treatment. The research project was managed by the Colorado Energy Research Institute (CERI) at the Colorado School of Mines (CSM) and involved personnel located at CERI, CSM, Stanford University, Pennsylvania State University, the University of Wyoming, the Argonne National Laboratory, the Gas Technology Institute, the Montana Bureau of Mining and Geology and PVES Inc., a private firm.

  20. Involvement of indole-3-acetic acid produced by Azospirillum brasilense in accumulating intracellular ammonium in Chlorella vulgaris.

    Science.gov (United States)

    Meza, Beatriz; de-Bashan, Luz E; Bashan, Yoav

    2015-01-01

    Accumulation of intracellular ammonium and activities of the enzymes glutamine synthetase (GS) and glutamate dehydrogenase (GDH) were measured when the microalgae Chlorella vulgaris was immobilized in alginate with either of two wild type strains of Azospirillum brasilense or their corresponding indole-3-acetic acid (IAA)-attenuated mutants. After 48 h of immobilization, both wild types induced higher levels of intracellular ammonium in the microalgae than their respective mutants; the more IAA produced, the higher the intracellular ammonium accumulated. Accumulation of intracellular ammonium in the cells of C. vulgaris followed application of four levels of exogenous IAA reported for A. brasilense and its IAA-attenuated mutants, which had a similar pattern for the first 24 h. This effect was transient and disappeared after 48 h of incubation. Immobilization of C. vulgaris with any bacteria strain induced higher GS activity. The bacterial strains also had GS activity, comparable to the activity detected in C. vulgaris, but weaker than when immobilized with the bacteria. When net activity was calculated, the wild type always induced higher GS activity than IAA-attenuated mutants. GDH activity in most microalgae/bacteria interactions resembled GS activity. When complementing IAA-attenuated mutants with exogenous IAA, GS activity in co-immobilized cultures matched those of the wild type A. brasilense immobilized with the microalga. Similarity occurred when the net GS activity was measured, and was higher with greater quantities of exogenous IAA. It is proposed that IAA produced by A. brasilense is involved in ammonium uptake and later assimilation by C. vulgaris. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  1. Effect of seed inoculation with Azospirillum brasilense and nitrogen fertilization rates on maize plant yield and silage quality

    Directory of Open Access Journals (Sweden)

    Fernando Reimann Skonieski

    Full Text Available ABSTRACT The objective of this study was to determine the effect of Azospirillum brasilense inoculation and different nitrogen (N rates applied as topdressing on the productivity of a maize crop and the nutritional value of maize silage. Two experiments were conducted in the 2012/2013 and 2013/2014 harvests. Treatments were distributed in a randomized block design in a factorial arrangement, which consisted of two maize hybrids (AS 1572 and Defender coupled with nitrogen rates (0, 60, 120, 240, and 480 kg ha-1, inoculated or uninoculated with A. brasilense. Inoculated seeds were treated with the A. brasilense strains Ab-V5 and Ab-V6. Inoculation with A. brasilense showed interaction with the hybrids, agricultural years, and nitrogen rates for the maize plant yield. In the 2012/2013 agricultural year, inoculation increased the AS 1572 hybrid silage yield by 6.16% and, in the 2013/2014 harvest, A. brasilense inoculation produced an increase of 16.15% for the Defender hybrid. Nitrogen fertilization applied at 0, 60, and 120 kg ha-1 N benefited the plants inoculated with A. brasilense. The statistical equations revealed that N rates between 0 and 184 kg ha-1 in A. brasilense inoculated plants raised the plant productivity for silage when compared with the control plants. Regarding the nutritional value of the silage, inoculation with A. brasilense increased the ether extract levels and total digestible nutrients and reduced the amount of acid detergent fiber. For all this, positive results with inoculation for silage yield are dependent on nitrogen fertilization rate. Inoculation with A. brasilense can promote changes in the maize silage quality, but with obtained results it is not possible to definitely conclude upon nutritive value of maize silage.

  2. The Azospirillum brasilense Che1 chemotaxis pathway controls swimming velocity, which affects transient cell-to-cell clumping.

    Science.gov (United States)

    Bible, Amber; Russell, Matthew H; Alexandre, Gladys

    2012-07-01

    The Che1 chemotaxis-like pathway of Azospirillum brasilense contributes to chemotaxis and aerotaxis, and it has also been found to contribute to regulating changes in cell surface adhesive properties that affect the propensity of cells to clump and to flocculate. The exact contribution of Che1 to the control of chemotaxis and flocculation in A. brasilense remains poorly understood. Here, we show that Che1 affects reversible cell-to-cell clumping, a cellular behavior in which motile cells transiently interact by adhering to one another at their nonflagellated poles before swimming apart. Clumping precedes and is required for flocculation, and both processes appear to be independently regulated. The phenotypes of a ΔaerC receptor mutant and of mutant strains lacking cheA1, cheY1, cheB1, or cheR1 (alone or in combination) or with che1 deleted show that Che1 directly mediates changes in the flagellar swimming velocity and that this behavior directly modulates the transient nature of clumping. Our results also suggest that an additional receptor(s) and signaling pathway(s) are implicated in mediating other Che1-independent changes in clumping identified in the present study. Transient clumping precedes the transition to stable clump formation, which involves the production of specific extracellular polysaccharides (EPS); however, production of these clumping-specific EPS is not directly controlled by Che1 activity. Che1-dependent clumping may antagonize motility and prevent chemotaxis, thereby maintaining cells in a metabolically favorable niche.

  3. Nano titania aided clustering and adhesion of beneficial bacteria to plant roots to enhance crop growth and stress management

    Science.gov (United States)

    Palmqvist, N. G. M.; Bejai, S.; Meijer, J.; Seisenbaeva, G. A.; Kessler, V. G.

    2015-05-01

    A novel use of Titania nanoparticles as agents in the nano interface interaction between a beneficial plant growth promoting bacterium (Bacillus amyloliquefaciens UCMB5113) and oilseed rape plants (Brassica napus) for protection against the fungal pathogen Alternaria brassicae is presented. Two different TiO2 nanoparticle material were produced by the Sol-Gel approach, one using the patented Captigel method and the other one applying TiBALDH precursor. The particles were characterized by transmission electron microscopy, thermogravimetric analysis, X-ray diffraction, dynamic light scattering and nano particle tracking analysis. Scanning electron microscopy showed that the bacterium was living in clusters on the roots and the combined energy-dispersive X-ray spectroscopy analysis revealed that titanium was present in these cluster formations. Confocal laser scanning microscopy further demonstrated an increased bacterial colonization of Arabidopsis thaliana roots and a semi-quantitative microscopic assay confirmed an increased bacterial adhesion to the roots. An increased amount of adhered bacteria was further confirmed by quantitative fluorescence measurements. The degree of infection by the fungus was measured and quantified by real-time-qPCR. Results showed that Titania nanoparticles increased adhesion of beneficial bacteria on to the roots of oilseed rape and protected the plants against infection.

  4. Effects of Azospirillum brasilense with genetically modified auxin biosynthesis gene ipdC upon the diversity of the indigenous microbiota of the wheat rhizosphere.

    Science.gov (United States)

    Baudoin, Ezékiel; Lerner, Anat; Mirza, M Sajjad; El Zemrany, Hamdy; Prigent-Combaret, Claire; Jurkevich, Edouard; Spaepen, Stijn; Vanderleyden, Jos; Nazaret, Sylvie; Okon, Yaacov; Moënne-Loccoz, Yvan

    2010-04-01

    The phytostimulatory properties of Azospirillum inoculants, which entail production of the phytohormone indole-3-acetic acid (IAA), can be enhanced by genetic means. However, it is not known whether this could affect their interactions with indigenous soil microbes. Here, wheat seeds were inoculated with the wild-type strain Azospirillum brasilense Sp245 or one of three genetically modified (GM) derivatives and grown for one month. The GM derivatives contained a plasmid vector harboring the indole-3-pyruvate/phenylpyruvate decarboxylase gene ipdC (IAA production) controlled either by the constitutive promoter PnptII or the root exudate-responsive promoter PsbpA, or by an empty vector (GM control). All inoculants displayed equal rhizosphere population densities. Only inoculation with either ipdC construct increased shoot biomass compared with the non-inoculated control. At one month after inoculation, automated ribosomal intergenic spacer analysis (ARISA) revealed that the effect of the PsbpA construct on bacterial community structure differed from that of the GM control, which was confirmed by 16S rDNA-based denaturing gradient gel electrophoresis (DGGE). The fungal community was sensitive to inoculation with the PsbpA construct and especially the GM control, based on ARISA data. Overall, fungal and bacterial communities displayed distinct responses to inoculation of GM A. brasilense phytostimulators, whose effects could differ from those of the wild-type.

  5. Sequencing and promoter analysis of the nifENXorf3orf5fdxAnifQ operon from Azospirillum brasilense Sp7

    Directory of Open Access Journals (Sweden)

    Potrich D.P.

    2001-01-01

    Full Text Available A 40-kb DNA region containing the major cluster of nif genes has been isolated from the Azospirillum brasilense Sp7 genome. In this region three nif operons have been identified: nifHDKorf1Y, nifENXorf3orf5fdxAnifQ and orf2nifUSVorf4. The operons containing nifENX and nifUSV genes are separated from the structural nifHDKorf1Y operon by about 5 kb and 10 kb, respectively. The present study shows the sequence analysis of the 6045-bp DNA region containing the nifENX genes. The deduced amino acid sequences from the open reading frames were compared to the nif gene products of other diazotrophic bacteria and indicate the presence of seven ORFs, all reading in the same direction as that of the nifHDKorf1Y operon. Consensus sigma54 and NifA-binding sites are present only in the promoter region upstream of the nifE gene. This promoter is activated by NifA protein and is approximately two-times less active than the nifH promoter, as indicated by the ß-galactosidase assays. This result suggests the differential expression of the nif genes and their respective products in Azospirillum.

  6. Polyhydroxyalcanoates of strains of Azospirillum spp. isolated of roots of Lycopersicon esculentum Mill. “tomato” and Oryza sativa L. “rice” in Lambayeque

    Directory of Open Access Journals (Sweden)

    Katty Baca

    2010-12-01

    Full Text Available In this work was determined the concentration of polyhydroxyalkanoates (PHAs of Azospirillum strains isolated from roots of Lycopersicon esculentum Mill "tomato" and Oryza sativa L. "rice" as an alternative to accumulation of petroleum-based plastics. Previously disinfected root were plated in Nfb semisolid medium where nitrogen-fixing bacteria were recognized by a whitish film on the surface and turn from green to blue. The genus Azospirillum was identified in Congo red agar medium, obtained 96 isolates of A. lipoferum and A. brasilense on tomato and rice. Batch fermentation was performed with broth Azotobacter modified feeding a saturated solution of malic acid every 12 hours and were stained with Sudan Black B. Strains were selected with the greatest number of PHAs granules (in tomato, 18 of A. lipoferum and 2 of A. brasilense; in rice, 10 of A. lipoferum and 10 of A. brasilense and quantified the biomass and PHAs. PHAs concentration reached 0.661 gL-1 in A. lipoferum KM(T-73 and 0.738 gL-1 in A. brasilense KM(T-19, both isolated from tomato. Strains of A. lipoferum and A. brasilense isolated from tomato reached a higher concentration of biomass and PHAs against the strains of rice.

  7. The cyclic-di-GMP diguanylate cyclase CdgA has a role in biofilm formation and exopolysaccharide production in Azospirillum brasilense.

    Science.gov (United States)

    Ramírez-Mata, Alberto; López-Lara, Lilia I; Xiqui-Vázquez, Ma Luisa; Jijón-Moreno, Saúl; Romero-Osorio, Angelica; Baca, Beatriz E

    2016-04-01

    In bacteria, proteins containing GGDEF domains are involved in production of the second messenger c-di-GMP. Here we report that the cdgA gene encoding diguanylate cyclase A (CdgA) is involved in biofilm formation and exopolysaccharide (EPS) production in Azospirillum brasilense Sp7. Biofilm quantification using crystal violet staining revealed that inactivation of cdgA decreased biofilm formation. In addition, confocal laser scanning microscopy analysis of green-fluorescent protein-labeled bacteria showed that, during static growth, the biofilms had differential levels of development: bacteria harboring a cdgA mutation exhibited biofilms with considerably reduced thickness compared with those of the wild-type Sp7 strain. Moreover, DNA-specific staining and treatment with DNase I, and epifluorescence studies demonstrated that extracellular DNA and EPS are components of the biofilm matrix in Azospirillum. After expression and purification of the CdgA protein, diguanylate cyclase activity was detected. The enzymatic activity of CdgA-producing cyclic c-di-GMP was determined using GTP as a substrate and flavin adenine dinucleotide (FAD(+)) and Mg(2)(+) as cofactors. Together, our results revealed that A. brasilense possesses a functional c-di-GMP biosynthesis pathway. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  8. Eficiência da inoculação de Azospirillum brasilense associado com enraizador no crescimento e na produção de alface

    Directory of Open Access Journals (Sweden)

    Antonio Anicete de Lima

    2017-06-01

    Full Text Available Objetivou-se avaliar o efeito da inoculação de Azospirillum brasilense (AzBr com e sem enraizador, no crescimento, produção de biomassa e resistência a pragas da alface, cultivar Lucy Brown. O experimento foi conduzido em casa de vegetação em recipientes plásticos com capacidade de 8,0 L no espaçamento 40 x 20 cm. O delineamento experimental foi de blocos casualizados em esquema fatorial (2x3+1, sendo o primeiro fator Azospirillum com e sem enraizador de crescimento e o segundo doses de nitrogênio em cobertura, 0%, 50% e 100% da recomendação de adubação e uma testemunha com adubação convencional, com quatro repetições. Em doses médias de 50% de N em cobertura, tanto o AzBr, quanto a associação AzBr mais enraizador, apresentaram um incremento significativo na massa fresca da parte aérea e de raízes de 19,36% e 23,66%, respectivamente, em relação a dose máxima de N e a testemunha. A massa seca da parte aérea não diferiu significativamente nos diferentes tratamentos, embora tenha mostrado um pequeno aumento com as doses crescente de N. A massa seca de raízes diminuiu 29,24% no tratamento com 100% de N, quando comparado ao tratamento sem cobertura nitrogenada mais AzBr. O estande final de plantas foi significativamente maior no tratamento no qual N não foi aplicado em cobertura, destacando-se a inoculação com AzBr, média de 96,98% de plantas estabelecidas, contra 51,56% na testemunha convencional, observando-se que até a dose média de N, houve uma maior tolerância das plantas aos sintomas de minas foliares e as viroses do Grupo Tospovirus.Azospirillum brasilense inoculation efficiency associated with rooting growth and production of lettuceAbstract: In the survey evaluated the effect of Azospirillum brasilense (AzBr inoculated with and without rooting, on growth, biomass production and lettuce pest resistance, cultivar Lucy Brown. The experiment was conducted in a greenhouse in plastic bags with 8.0 L capacity in

  9. Beneficial and adverse effects of chemopreventive agents

    International Nuclear Information System (INIS)

    Lee, Byung Mu; Park, Kwang-Kyun

    2003-01-01

    The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents

  10. Nanoscale particles in technological processes of beneficiation

    Directory of Open Access Journals (Sweden)

    Sergey I. Popel

    2014-04-01

    Full Text Available Background: Cavitation is a rather common and important effect in the processes of destruction of nano- and microscale particles in natural and technological processes. A possible cavitation disintegration of polymineral nano- and microparticles, which are placed into a liquid, as a result of the interaction of the particles with collapsed cavitation bubbles is considered. The emphasis is put on the cavitation processes on the interface between liquid and fine solid particles, which is suitable for the description of the real situations.Results: The results are illustrated for the minerals that are most abundant in gold ore. The bubbles are generated by shock loading of the liquid heated to the boiling temperature. Possibilities of cavitation separation of nano- and microscale monomineral fractions from polymineral nano- and microparticles and of the use of cavitation for beneficiation are demonstrated.Conclusion: The cavitation disintegration mechanism is important because the availability of high-grade deposits in the process of mining and production of noble metals is decreasing. This demands for an enhancement of the efficiency in developing low-grade deposits and in reprocessing ore dumps and tailings, which contain a certain amount of noble metals in the form of finely disseminated fractions. The cavitation processes occuring on the interface between liquid and fine solid particles are occasionally more effective than the bulk cavitation processes that were considered earlier.

  11. The beneficial effect of yoga in diabetes.

    Science.gov (United States)

    Malhotra, Varun; Singh, Savita; Tandon, Om Prakash; Sharma, Suman Bala

    2005-12-01

    Twenty NIDDM subjects (mild to moderate diabetics) in the age group of 30-60 years were selected from the out patient clinic of G.T.B. hospital. They were on a 40 days yoga asana regime under the supervision of a yoga expert. 13 specific Yoga asanas Surya Namaskar, Trikonasana, Tadasana, Sukhasana, Padmasana, Bhastrika Pranayama, Pashimottanasana, Ardhmatsyendrasana, Pawanmuktasana, Bhujangasana, Vajrasana, Dhanurasana and Shavasana are beneficial for diabetes mellitus. Serum insulin, plasma fasting and one hour postprandial blood glucose levels and anthropometric parameters were measured before and after yoga asanas. The results indicate that there was significant decrease in fasting glucose levels from basal 208.3 +/- 20.0 to 171.7 +/- 19.5 mg/dl and one hour postprandial blood glucose levels decreased from 295.3 +/- 22.0 to 269.7 +/- 19.9 mg/dl. The exact mechanism as to how these postures and controlled breathing interact with somatoendocrine mechanism affecting insulin kinetics was worked out. A significant decrease in waist-hip ratio and changes in insulin levels were also observed, suggesting a positive effect of yoga asanas on glucose utilisation and fat redistribution in NIDDM. Yoga asanas may be used as an adjunct with diet and drugs in the management of Type 2 diabetes.

  12. Clinical supervision, is it mutually beneficial

    International Nuclear Information System (INIS)

    Adams, E.J.

    2000-01-01

    Full text: Clinical education in Nuclear Medicine is essential for student learning as it enables them to develop knowledge and competence and put theory into practice. While the benefit to the student is clear, the clinical education experience should be mutually beneficial. The role of the clinical supervisor involves teaching, role modelling, management and assessment. It could be assumed that the Supervisor would find the teaching role leading to increased knowledge; role modelling leading to increased reflection which improves practice; management skills being enhanced and assessment improving critical evaluation skills. The aim of this study was to assess the perceived benefits of taking on the role of a clinical supervisor. Clinical Supervisors participating in the Nuclear Medicine program were surveyed. Questions were grouped into three main categories - professional, interpersonal and communication. A Likert scale was used to assess perceived level of benefit and open-ended questions were included to obtain additional understanding of Supervisors' perceptions. Results from the survey indicate that 64% of supervisors felt an increase in work satisfaction by taking students, 68% agreed their level of performance was improved and 61% agreed that it deepened their understanding of Nuclear Medicine. It is concluded that respondents perceived a positive benefit to areas within the role of Clinical Supervisor. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  13. Beneficial and adverse effects of chemopreventive agents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Mu; Park, Kwang-Kyun

    2003-03-01

    The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents.

  14. Beneficial effects of antioxidative lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hisako Nakagawa

    2017-01-01

    Full Text Available Oxidative stress is caused by exposure to reactive oxygen intermediates. The oxidative damage of cell components such as proteins, lipids, and nucleic acids one of the important factors associated with diabetes mellitus, cancers and cardiovascular diseases. This occurs as a result of imbalance between the generations of oxygen derived radicals and the organism’s antioxidant potential. The amount of oxidative damage increases as an organism ages and is postulated to be a major causal factor of senescence. To date, many studies have focused on food sources, nutrients, and components that exert antioxidant activity in worms, flies, mice, and humans. Probiotics, live microorganisms that when administered in adequate amounts provide many beneficial effects on the human health, have been attracting growing interest for their health-promoting effects, and have often been administered in fermented milk products. In particular, lactic acid bacteria (LAB are known to conferre physiologic benefits. Many studies have indicated the antioxidative activity of LAB. Here we review that the effects of lactic acid bacteria to respond to oxidative stress, is connected to oxidative-stress related disease and aging.

  15. FACEBOOK AND WHATSAPP: BENEFICIAL OR HARMFUL?

    Directory of Open Access Journals (Sweden)

    Sankalp Raj

    2015-04-01

    Full Text Available New innovations and advances in science and technology in the present day have made considerable and significant changes in the lifestyle of people all around the globe. Communication from one part of the world to another is possible at the hit of a button . Social networking is being rampantly used everywhere and by everybody, be it youngsters or the older generation. Facebook and Whatsapp are the most commonly used means of communication in social networking at present. Smart phones functioning as minicomp uters with fast internet connectivity in the pockets of today’s technosavy generation have made them create and spend most of their time interacting with people in a virtual world. There is an urgent need to understand the dynamics of social media and its effects on the lifestyle of people. Studies documenting the same have been very few. This study was conducted to understand the benefits and harms towards health and academics of MBBS students. This cross - sectional study on 147 MBBS students revealed inter esting findings and opinions of the students. Effects of Facebook and What Sapp on productivity and sleep disturbances due to it were the significant findings of the study. Facebook and Whatsapp can be considered both beneficial and harmful and it solely d epends on how it is being put to use

  16. Extreme Ionizing-Radiation-Resistant Bacterium

    Science.gov (United States)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2013-01-01

    potential for transfer, and subsequent proliferation, on another solar body such as Mars and Europa. These organisms are more likely to escape planetary protection assays, which only take into account presence of spores. Hence, presences of extreme radiation-resistant Deinococcus in the cleanroom facility where spacecraft are assembled pose a serious risk for integrity of life-detection missions. The microorganism described herein was isolated from the surfaces of the cleanroom facility in which the Phoenix Lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. This bacterium exhibits very low 16SrRNA similarity with any other environmental isolate reported to date. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Deinococcus and represents a novel species. The name Deinococcus phoenicis was proposed after the Phoenix spacecraft, which was undergoing assembly, testing, and launch operations in the spacecraft assembly facility at the time of isolation. D. phoenicis cells exhibited higher resistance to ionizing radiation (cobalt-60; 14 kGy) than the cells of the D. radiodurans (5 kGy). Thus, it is in the best interest of NASA to thoroughly characterize this organism, which will further assess in determining the potential for forward contamination. Upon the completion of genetic and physiological characteristics of D. phoenicis, it will be added to a planetary protection database to be able to further model and predict the probability of forward contamination.

  17. Beneficiation-hydroretort processing of US oil shales: Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    None

    1989-01-01

    This report has been divided into three volumes. Volume I describes the MRI beneficiation work. In addition, Volume I presents the results of joint beneficiation-hydroretorting studies and provides an economic analysis of the combined beneficiation-hydroretorting approach for processing Eastern oil shales. Volume II presents detailed results of hydroretorting tests made by HYCRUDE/IGT on raw and beneficiated oil shales prepared by MRI. Volume III comprises detailed engineering design drawings and supporting data developed by the Roberts and Schaefer Company, Engineers and Contractors, Salt Lake City, Utah, in support of the capital and operating costs for a conceptual beneficiation plant processing an Alabama oil shale.

  18. Realocação de nitrogênio e de biomassa para os grãos, em trigo submetido a inoculação de Azospirillum Reallocation of nitrogen and biomass to the seeds in wheat inoculated with Azospirillum bacteria

    Directory of Open Access Journals (Sweden)

    AGOSTINHO DIRCEU DIDONET

    2000-02-01

    Full Text Available Estudou-se, em condições de campo, o efeito de inoculante turfoso em pó contendo bactérias do gênero Azospirillum no rendimento de grãos e na remobilização de N e de biomassa para os grãos de trigo (Triticum aestivum L., cultivar Embrapa 16. Usaram-se como inoculantes, a estirpe de Azospirillum brasilense 245 e o isolado 10 de Azospirillum lipoferum. Em cada tratamento de inoculação, e também sem inoculação, aplicaram-se diferentes doses de N em diferentes estádios de desenvolvimento das plantas, distribuídos em blocos ao acaso com parcelas subdivididas. Na antese e na maturação fisiológica, avaliaram-se o acúmulo de massa seca e N total nas diferentes partes da planta. Na colheita, além do rendimento de grãos, avaliaram-se também o índice de colheita para biomassa e para N, os principais componentes do rendimento e o teor de N total de grãos. Os resultados ainda preliminares evidenciaram que, mesmo não havendo efeito da inoculação no rendimento de grãos, houve um melhor alocamento de N e de biomassa para os grãos, resultando em maior massa de mil grãos e em menor quantidade de N restante na palha das plantas na maturação fisiológica. Esses efeitos resultaram de um menor número de espigas m-2, provavelmente devido à morte de afilhos, fator que determinou maior disponibilidade de N e de biomassa às espigas e grãos restantes.The effect of inoculating wheat (Triticum aestivum L. seeds, cultivar Embrapa 16, with powder peat inoculant containing Azospirillum bacteria on yield and remobilization of nitrogen and biomass was studied under field conditions. The strain of Azospirillum brasilense 245 and the isolate 10 of Azospirillum lipoferum were used as inoculants. Different rates of nitrogen were applied at varying stages of plant growth for each inoculated and non-inoculated treatment, distributed in blocks at random with split plots. The accumulation of dry matter and total nitrogen in plant parts was evaluated

  19. Responses of a soil bacterium, Pseudomonas chlororaphis O6 to commercial metal oxide nanoparticles compared with responses to metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Dimkpa, Christian O., E-mail: cdimkpa@usu.edu [Department of Biological Engineering, Utah State University, Logan, UT 84322 (United States); Calder, Alyssa; Britt, David W. [Department of Biological Engineering, Utah State University, Logan, UT 84322 (United States); McLean, Joan E. [Utah Water Research Laboratory, Utah State University, Logan, UT 84322 (United States); Anderson, Anne J. [Department of Biology, Utah State University, Logan, UT 84322 (United States)

    2011-07-15

    The toxicity of commercially-available CuO and ZnO nanoparticles (NPs) to pathogenic bacteria was compared for a beneficial rhizosphere isolate, Pseudomonas chlororaphis O6. The NPs aggregated, released ions to different extents under the conditions used for bacterial exposure, and associated with bacterial cell surface. Bacterial surface charge was neutralized by NPs, dependent on pH. The CuO NPs were more toxic than the ZnO NPs. The negative surface charge on colloids of extracellular polymeric substances (EPS) was reduced by Cu ions but not by CuO NPs; the EPS protected cells from CuO NPs-toxicity. CuO NPs-toxicity was eliminated by a Cu ion chelator, suggesting that ion release was involved. Neither NPs released alkaline phosphatase from the cells' periplasm, indicating minimal outer membrane damage. Accumulation of intracellular reactive oxygen species was correlated with CuO NPs lethality. Environmental deposition of NPs could create niches for ion release, with impacts on susceptible soil microbes. - Highlights: > Toxicity of metallic nanoparticles (NPs) was evaluated in a beneficial bacterium, Pseudomonas chlororaphis O6 (PcO6). > Aggregated commercial CuO and ZnO NPs released Cu and Zn ions and changed bacterial surface charge, depending on pH. > The NPs were toxic to PcO6 through NP-specific, but also ion release mechanisms. > Reactive oxygen species were produced by CuO NP and Cu ion at lethal concentrations, but bacterial EPS protected against Cu. > The periplasmic marker, alkaline phosphate, activity was increased by the NPs and ions. - Aggregated CuO and ZnO nanoparticles release ions and cause different toxicities in a beneficial soil bacterium.

  20. Responses of a soil bacterium, Pseudomonas chlororaphis O6 to commercial metal oxide nanoparticles compared with responses to metal ions

    International Nuclear Information System (INIS)

    Dimkpa, Christian O.; Calder, Alyssa; Britt, David W.; McLean, Joan E.; Anderson, Anne J.

    2011-01-01

    The toxicity of commercially-available CuO and ZnO nanoparticles (NPs) to pathogenic bacteria was compared for a beneficial rhizosphere isolate, Pseudomonas chlororaphis O6. The NPs aggregated, released ions to different extents under the conditions used for bacterial exposure, and associated with bacterial cell surface. Bacterial surface charge was neutralized by NPs, dependent on pH. The CuO NPs were more toxic than the ZnO NPs. The negative surface charge on colloids of extracellular polymeric substances (EPS) was reduced by Cu ions but not by CuO NPs; the EPS protected cells from CuO NPs-toxicity. CuO NPs-toxicity was eliminated by a Cu ion chelator, suggesting that ion release was involved. Neither NPs released alkaline phosphatase from the cells' periplasm, indicating minimal outer membrane damage. Accumulation of intracellular reactive oxygen species was correlated with CuO NPs lethality. Environmental deposition of NPs could create niches for ion release, with impacts on susceptible soil microbes. - Highlights: → Toxicity of metallic nanoparticles (NPs) was evaluated in a beneficial bacterium, Pseudomonas chlororaphis O6 (PcO6). → Aggregated commercial CuO and ZnO NPs released Cu and Zn ions and changed bacterial surface charge, depending on pH. → The NPs were toxic to PcO6 through NP-specific, but also ion release mechanisms. → Reactive oxygen species were produced by CuO NP and Cu ion at lethal concentrations, but bacterial EPS protected against Cu. → The periplasmic marker, alkaline phosphate, activity was increased by the NPs and ions. - Aggregated CuO and ZnO nanoparticles release ions and cause different toxicities in a beneficial soil bacterium.

  1. Beneficial Reuse of San Ardo Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Robert A. Liske

    2006-07-31

    This DOE funded study was performed to evaluate the potential for treatment and beneficial reuse of produced water from the San Ardo oilfield in Monterey County, CA. The potential benefits of a successful full-scale implementation of this project include improvements in oil production efficiency and additional recoverable oil reserves as well as the addition of a new reclaimed water resource. The overall project was conducted in two Phases. Phase I identified and evaluated potential end uses for the treated produced water, established treated water quality objectives, reviewed regulations related to treatment, transport, storage and use of the treated produced water, and investigated various water treatment technology options. Phase II involved the construction and operation of a small-scale water treatment pilot facility to evaluate the process's performance on produced water from the San Ardo oilfield. Cost estimates for a potential full-scale facility were also developed. Potential end uses identified for the treated water include (1) agricultural use near the oilfield, (2) use by Monterey County Water Resources Agency (MCWRA) for the Salinas Valley Water Project or Castroville Seawater Intrusion Project, (3) industrial or power plant use in King City, and (4) use for wetlands creation in the Salinas Basin. All of these uses were found to have major obstacles that prevent full-scale implementation. An additional option for potential reuse of the treated produced water was subsequently identified. That option involves using the treated produced water to recharge groundwater in the vicinity of the oil field. The recharge option may avoid the limitations that the other reuse options face. The water treatment pilot process utilized: (1) warm precipitation softening to remove hardness and silica, (2) evaporative cooling to meet downstream temperature limitations and facilitate removal of ammonia, and (3) reverse osmosis (RO) for removal of dissolved salts, boron

  2. Distinct Domains of CheA Confer Unique Functions in Chemotaxis and Cell Length in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Gullett, Jessica M; Bible, Amber; Alexandre, Gladys

    2017-07-01

    Chemotaxis is the movement of cells in response to gradients of diverse chemical cues. Motile bacteria utilize a conserved chemotaxis signal transduction system to bias their motility and navigate through a gradient. A central regulator of chemotaxis is the histidine kinase CheA. This cytoplasmic protein interacts with membrane-bound receptors, which assemble into large polar arrays, to propagate the signal. In the alphaproteobacterium Azospirillum brasilense , Che1 controls transient increases in swimming speed during chemotaxis, but it also biases the cell length at division. However, the exact underlying molecular mechanisms for Che1-dependent control of multiple cellular behaviors are not known. Here, we identify specific domains of the CheA1 histidine kinase implicated in modulating each of these functions. We show that CheA1 is produced in two isoforms: a membrane-anchored isoform produced as a fusion with a conserved seven-transmembrane domain of unknown function (TMX) at the N terminus and a soluble isoform similar to prototypical CheA. Site-directed and deletion mutagenesis combined with behavioral assays confirm the role of CheA1 in chemotaxis and implicate the TMX domain in mediating changes in cell length. Fluorescence microscopy further reveals that the membrane-anchored isoform is distributed around the cell surface while the soluble isoform localizes at the cell poles. Together, the data provide a mechanism for the role of Che1 in controlling multiple unrelated cellular behaviors via acquisition of a new domain in CheA1 and production of distinct functional isoforms. IMPORTANCE Chemotaxis provides a significant competitive advantage to bacteria in the environment, and this function has been transferred laterally multiple times, with evidence of functional divergence in different genomic contexts. The molecular principles that underlie functional diversification of chemotaxis in various genomic contexts are unknown. Here, we provide a molecular

  3. Effect of Nitrogen and Zinc Sulphate Fertilizers and Azotobacter and Azospirillum Biofertilizer on Yield and Growth Traits of Rapeseed (Brassica napus L.

    Directory of Open Access Journals (Sweden)

    N. Jafari

    2013-06-01

    Full Text Available In order to study the effects of simultaneous application of nitrogen (N and ZnSO4 fertilizers and biofertilizer (Azotobacter and Azospirillum on grain yield and growth traits of rapeseed, Hyola308 cultivar, a field experiment, with split plot factorial layout based on randomized complete blocks design with three replications, was conducted at Research Field of Faculty of Agriculture, University of Guilan, Rasht, Iran, during 2007-2008 growing season. Nitrogen fertilizer at four levels (0, 50, 100 and 150 kg/ha were the main plot and ZnSO4 fertilizer at two levels (0 and 50 kg/ha and biofertilizer at two levels (with and without biofertilizer were arranged in sub-plots. Results showed that maximum and minimum leaf area indices at flowering stage (average of 1.29 and 0.95, respectively were obtained in 150 kg/ha N+ZnSO4+ biofertilizer and in 50 kg/ha N+ no ZnSO4+ no biofertilizer treatments. Maximum and minimum crop growth rates at flowering stage (average of 5.89 and 3.19 g/m2.GDD, respectively were obtained in 150 kg/ha N+ZnSO4+ biofertilizer and control treatments. Maximum and minimum grain yields (2568, 2468 and 543 kg/ha, respectively were obtained in 150 kg/ha N+ with/without ZnSO4+ biofertilizer and control (no fertilizer treatments. Maximum and minimum oil yields (42.8 and 37.3%, respectively were measured in 0 kg/ha N+ZnSO4+ biofertilizer and 150 kg/ha N+ no ZnSO4+ no biofertilizer treatments. Since there was no significant difference between 150 and 100 kg/ha N+ZnSO4+ biofertilizer treatments in terms of impact on canola grain yield and growth traits, it seems that application of biofertilizer (Azotobacter and Azospirillum, without any reduction in yield, increased grain production and oil content and saved 50 kg/ha of N fertilizer. Biofertilizer (Azotobacter and Azospirillum, along with zinc and sulfur, produced phytohormones, and N fertilizer increased dry matter accumulation and leaf area index (by increasing carbohydrate conversion

  4. Maize Inoculation with Azospirillum brasilense Ab-V5 Cells Enriched with Exopolysaccharides and Polyhydroxybutyrate Results in High Productivity under Low N Fertilizer Input

    Science.gov (United States)

    Oliveira, André L. M.; Santos, Odair J. A. P.; Marcelino, Paulo R. F.; Milani, Karina M. L.; Zuluaga, Mónica Y. A.; Zucareli, Claudemir; Gonçalves, Leandro S. A.

    2017-01-01

    Although Azospirillum strains used in commercial inoculant formulations presents diazotrophic activity, it has been reported that their ability to produce phytohormones plays a pivotal role in plant growth-promotion, leading to a general recommendation of its use in association with regular N-fertilizer doses. In addition, a high variability in the effectiveness of Azospirillum inoculants is still reported under field conditions, contributing to the adoption of the inoculation technology as an additional management practice rather than its use as an alternative practice to the use of chemical inputs in agriculture. To investigate whether the content of stress-resistance biopolymers would improve the viability and performance of Azospirillum inoculants when used as substitute of N-fertilizers, biomass of A. brasilense strain Ab-V5 enriched in exopolysaccharides (EPS) and polyhydroxybutirate (PHB) was produced using a new culture medium developed by factorial mixture design, and the effectiveness of resulting inoculants was evaluated under field conditions. The culture medium formulation extended the log phase of A. brasilense cultures, which presented higher cell counts and increased EPS and PHB contents than observed in the cultures grown in the OAB medium used as control. An inoculation trial with maize conducted under greenhouse conditions and using the biopolymers-enriched Ab-V5 cells demonstrated the importance of EPS and PHB to the long term bacterial viability in soil and to the effectiveness of inoculation. The effectiveness of liquid and peat inoculants prepared with Ab-V5 cells enriched with EPS and PHB was also evaluated under field conditions, using maize as target crop along different seasons, with the inoculants applied directly over seeds or at topdressing under limiting levels of N-fertilization. No additive effect on yield resulted from inoculation under high N fertilizer input, while inoculated plants grown under 80% reduction in N fertilizer

  5. Maize Inoculation with Azospirillum brasilense Ab-V5 Cells Enriched with Exopolysaccharides and Polyhydroxybutyrate Results in High Productivity under Low N Fertilizer Input

    Directory of Open Access Journals (Sweden)

    André L. M. Oliveira

    2017-09-01

    Full Text Available Although Azospirillum strains used in commercial inoculant formulations presents diazotrophic activity, it has been reported that their ability to produce phytohormones plays a pivotal role in plant growth-promotion, leading to a general recommendation of its use in association with regular N-fertilizer doses. In addition, a high variability in the effectiveness of Azospirillum inoculants is still reported under field conditions, contributing to the adoption of the inoculation technology as an additional management practice rather than its use as an alternative practice to the use of chemical inputs in agriculture. To investigate whether the content of stress-resistance biopolymers would improve the viability and performance of Azospirillum inoculants when used as substitute of N-fertilizers, biomass of A. brasilense strain Ab-V5 enriched in exopolysaccharides (EPS and polyhydroxybutirate (PHB was produced using a new culture medium developed by factorial mixture design, and the effectiveness of resulting inoculants was evaluated under field conditions. The culture medium formulation extended the log phase of A. brasilense cultures, which presented higher cell counts and increased EPS and PHB contents than observed in the cultures grown in the OAB medium used as control. An inoculation trial with maize conducted under greenhouse conditions and using the biopolymers-enriched Ab-V5 cells demonstrated the importance of EPS and PHB to the long term bacterial viability in soil and to the effectiveness of inoculation. The effectiveness of liquid and peat inoculants prepared with Ab-V5 cells enriched with EPS and PHB was also evaluated under field conditions, using maize as target crop along different seasons, with the inoculants applied directly over seeds or at topdressing under limiting levels of N-fertilization. No additive effect on yield resulted from inoculation under high N fertilizer input, while inoculated plants grown under 80% reduction in

  6. Antagonistic bioactivity of an endophytic bacterium isolated from ...

    African Journals Online (AJOL)

    Antagonistic bioactivity of an endophytic bacterium isolated from Epimedium brevicornu Maxim. R He, G Wang, X Liu, C Zhang, F Lin. Abstract. Endophytic bacteria are one of the most potential biological control agents in plant disease protection. The aim of this work was to evaluate the antimicrobial activities of a strain of ...

  7. The physiology of the filamentous bacterium Microthrix parvicella

    NARCIS (Netherlands)

    Slijkhuis, H.

    1983-01-01

    A study has been made of the physiology of Microthrix parvicella. This filamentous bacterium often causes poor settleability of activated sludge in oxidation ditches supplied with domestic sewage. The organism was found to utilize only long chain fatty acids (preferably in

  8. The Bacterium That Got Infected by a Cow! - Horizontal Gene

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 1. The Bacterium That Got Infected by a Cow! - Horizontal Gene Transfer and Evolution. Saurabh Dhawan Tomás John Ryan. General Article Volume 12 Issue 1 January 2007 pp 49-59 ...

  9. Monitoring of a novel bacterium, Lactobacillus thermotolerans , in ...

    African Journals Online (AJOL)

    Abstract. We successfully established fluorescence in situ hybridization (FISH) method for specific detection and enumeration of a novel bacterium, Lactobacillus thermotolerans, in chicken feces. The specific FISH probes were designed based on the L. thermotolerans 16S rRNA gene sequences, and these sequences were ...

  10. methoxyethanol by a new bacterium isolate Pseudomonas sp. Strain

    African Journals Online (AJOL)

    Michael Horsfall

    A 2-methoxyethanol degrading bacterium was isolated from anaerobic sludge of a municipal sewage from ... Stoichiometrically, the strain utilized one mole of oxygen per one mole of 2-methoxyethanol instead of ... physiological and biochemical characterization of the .... observed with acetate and the intact resting cells.

  11. Non-obligate predatory bacterium burkholderia casidaeand uses thereof

    OpenAIRE

    1998-01-01

    A novel predator bacterium Burkholderia casidae is disclosed. The invention is directed to the isolation and use of Burkholderia casidae to control microbial diseases of plants. The genetic, biochemical and physiological characteristics of Burkholderia casidae are described. Biocontrol compositions comprising Burkholderia casidae, and antimicrobial compounds and antimicrobial preparations prepared from Burkholderia casidae are also disclosed, as are methods for accomplishing all of the forego...

  12. Non-obligate predatory bacterium Burkholderia casidae and uses thereof

    OpenAIRE

    2001-01-01

    A novel predator bacterium Burkholderia casidae is disclosed. The invention is directed to the isolation and use of Burkholderia casidae to control microbial diseases of plants. The genetic, biochemical and physiological characteristics of Burkholderia casidae are described. Biocontrol compositions comprising Burkholderia casidae, and antimicrobial compounds and antimicrobial preparations prepared from Burkholderia casidae are also disclosed, as are methods for accomplishing all of the forego...

  13. Detecção de Azospirillum amazonense em raízes e rizosfera de orchidaceae e de outras famílias vegetais

    Directory of Open Access Journals (Sweden)

    A. Lange

    2002-06-01

    Full Text Available Azospirillum amazonense é uma bactéria fixadora de N2 atmosférico de ampla ocorrência, principalmente em associações radiculares com gramíneas e palmeiras. Para verificar sua presença em outras espécies vegetais, ainda não estudadas, e a eficiência de meios para sua detecção, foram testados os meios Fam e LGI para contagens em solo rizosférico ou em culturas de enriquecimento com solo rizosférico, ecto e endorrizosfera. A. amazonense foi detectada no solo rizosférico, ecto e endorrizosfera de várias espécies de monocotiledôneas, incluindo Orchidaceae e dicotiledôneas, sendo o meio Fam mais eficiente para sua detecção

  14. Assessment of N2 fixing efficiency of Beijerinckia indica and Azospirillum brasilense in Sorghum (Sorghum bicolor (L.) moench) using 15N tracer

    International Nuclear Information System (INIS)

    Kanimoli, S.; Marimuthu, P.; Arulmozhiselvan, K.

    2010-01-01

    For studying the benefits of inoculation of N 2 fixing diazotrophs in the root zone of sorghum crop, a pot culture was conducted on neutral red sandy loam soil with sorghum cv. CO26, using 15 N tracer. At the end of 45 days duration after sowing, Beijerinckia indica inoculation contributed 56.9 per cent N derived from N 2 fixation, out of total N concentration in whole drymatter of sorghum plant. It proved to be the efficient N 2 fixer by contributing N from N 2 fixation to the tune of 17.6 Kg -1 . Accumulation of N derived from N 2 fixation from B. indica was primarily in leaf blade (50.0%) followed by stem (31.8%), leaf sheath (14.0%) and root (4.2%). Inoculation of Azospirillum brasllense accelerated uptake of N from soil and fertilizer N sources compared to B. indica and hence registered low N fixation. (author)

  15. A CheR/CheB fusion protein is involved in cyst cell development and chemotaxis in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Wu, Lixian; Cui, Yanhua; Hong, Yuanyuan; Chen, Sanfeng

    2011-12-20

    We here report the sequence and functional analysis of cstB of Azospirillum brasilense Sp7. The predicted cstB contains C-terminal two PAS domains and N-terminal part which has similarity with CheB-CheR fusion protein. cstB mutants had reduced swarming ability compared to that of A. brasilense wild-type strain, implying that cstB was involved in chemotaxis in A. brasilense. A microscopic analysis revealed that cstB mutants developed mature cyst cells more quickly than wild type, indicating that cstB is involved in cyst formation. cstB mutants were affected in colony morphology and the production of exopolysaccharides (EPS) which are essential for A. brasilense cells to differentiate into cyst-like forms. These observations suggested that cstB was a multi-effector involved in cyst development and chemotaxis in A. brasilense. Copyright © 2010 Elsevier GmbH. All rights reserved.

  16. Polihidroxialcanoatos de cepas de Azospirillum spp. aisladas de raíces de Lycopersicon esculentum Mill. “tomate” y Oryza sativa L. “arroz” en Lambayeque

    Directory of Open Access Journals (Sweden)

    Katty Baca

    2010-01-01

    Full Text Available En este trabajo se determinó la concentración de polihidroxialcanoatos (PH As de cepas de Azospirillum aisladas de raíces de Lycopersicon esculentum Mill. “tomate” y Oryza sativa L. “arroz”, como una alternativa ante la acumulación de plásticos derivados del petróleo. R aíces previamente desinfectadas se sembraron en medio Nfb se misólido, donde las bacterias fijadoras de nitrógeno se reconocieron por una película blanquecina bajo la superficie y el viraje del indicador al azul. El género Azospirillum se identificó en medio rojo de Congo, obteniéndose 96 cepas de A. lipoferum y A. brasilense en tomate y arroz. Se realizó una fermentación discontinua con caldo Azotobacter modificado, alimentando con una solución saturada de ácido málico cada 12 horas y se realizaron tinciones con Sudán Negro B. Se seleccionaron las cepas con mayor nú mero de gránulos de PHAs (en tomate , 18 de A. lipoferum y 2 de A. brasilense y en arroz, 10 de A. lipoferum y 10 de A. brasilense y se cuantificó la biomasa y PHAs. La concentración de PHAs alcanzó 0 . 661 gL - 1 en A. lipoferum KM(T - 73 y 0 . 738 gL - 1 en A. br asilense KM(T - 19. Las cepas de A. lipoferum y A. brasilense aisladas de tomate alcanzaron una mayor concentración de biomasa y PHAs frente a las cepas aisladas de arroz.

  17. Restrição do 16S-23S DNAr intergênico para avaliação da diversidade de Azospirillum amazonense isolado de Brachiaria spp. Restriction of 16S-23S intergenic rDNA for diversity evaluation of Azospirillum amazonense isolated from different Brachiaria spp.

    Directory of Open Access Journals (Sweden)

    Fábio Bueno dos Reis Junior

    2006-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a diversidade intra-específica de isolados de Azospirillum amazonense e estabelecer a possível influência de diferentes espécies de Brachiaria ssp. e diferentes condições edafoclimáticas. A caracterização da diversidade desses isolados foi conduzida, utilizando-se a análise de restrição da região intergênica 16S-23S DNAr. As estirpes estudadas separaram-se em dois grupos, definidos a 56% de similaridade. As espécies de Brachiaria ssp. influenciaram a diversidade de estirpes. A maioria dos isolados oriundos de B. decumbens e B. brizantha está inserida no primeiro grupo, enquanto os oriundos de B. humidicola concentram-se no segundo grupo.The aim of this work was to study the intra-specific diversity of Azospirillum amazonense isolates and to establish possible influences of different Brachiaria spp. and edaphoclimatic conditions. The characterization of the diversity among the isolates of A. amazonense studied was conducted using restriction analysis of the 16S-23S rDNA intergenic spacer region. The evaluated strains were separated in two groups, defined at 56% of similarity. Brachiaria spp. showed effects on strain diversity. Most part of the isolates from B. decumbens and B. brizantha are inserted in the first group, while B. humidicola isolates concentrate in the second group.

  18. Beneficial and Deleterious Bacterial - Host Interactions in Chronic Wound Pathophysiology

    Science.gov (United States)

    2015-04-02

    treatment with P. acnes that had been incubated in PBS.70 This study suggests that glycerol fermentation and the production of compounds, like...SE, Wolcott RD, Zischkau AM. Identification of yeast in chronic wounds using new pathogen-detection technologies. J Wound Care. 2009;18(3):103–104...University. 2008;11(3):111–116. 70. Shu M, Wang Y, Yu J, et al. Fermentation of Propionibacterium acnes, a commensal bacterium in the human skin

  19. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion.

    Directory of Open Access Journals (Sweden)

    Solimabi Wahidullah

    Full Text Available As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl with salicylic acid (3-8 were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9-12, metabolites produced by the bacterium include antimicrobial indole (13 and β-carbolines, norharman (14, harman (15 and methyl derivative (16, which are beneficial to the host and the environment.

  20. Biosorption of heavy metals by a marine bacterium

    International Nuclear Information System (INIS)

    Iyer, Anita; Mody, Kalpana; Jha, Bhavanath

    2005-01-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here

  1. Biosorption of heavy metals by a marine bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Anita [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India); Mody, Kalpana [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)]. E-mail: khmody@csmcri.org; Jha, Bhavanath [Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat (India)

    2005-03-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here.

  2. Growth of a Strictly Anaerobic Bacterium on Furfural (2-Furaldehyde)

    OpenAIRE

    Brune, Gerhard; Schoberth, Siegfried M.; Sahm, Hermann

    1983-01-01

    A strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. Furfural is one of the major components of this condensate. This furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. Acetic acid was the major fermentation product. This organism could also use ethanol, lactate, pyruvate, or fumarate and c...

  3. Antibacterial marine bacterium deter luminous vibriosis in shrimp larvae

    OpenAIRE

    Abraham, T.J.

    2004-01-01

    Inhibitory activity of a marine pigmented bacterium - Alteromonas sp. - isolated from Penaeus monodon Fabricius larva against pathogenic and environmental isolates of Vibrio harveyi was studied. All the isolates were inhibited to varying degrees by Alteromonas sp. in vitro. The antibacterial substance produced by the Alteromonas sp. was soluble in organic solvent and closely bound to the external surface of bacterial cells. The antibacterial Alteromonas sp., when allowed to colonize on shrimp...

  4. Initiation of chromosomal replication in predatory bacterium Bdellovibrio bacteriovorus

    Directory of Open Access Journals (Sweden)

    Lukasz Makowski

    2016-11-01

    Full Text Available Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase and replicating cells (the intracellular-growth phase. The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box (5’-NN(A/TTCCACA-3’. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus. We compared the architecture of the DnaA–oriC complexes (orisomes in homologous (oriC and DnaA from B. bacteriovorus and heterologous (BdoriC and DnaA from prey, E. coli or P. aeruginosa systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium.

  5. A novel radio-tolerant astaxanthin-producing bacterium reveals a new astaxanthin derivative: astaxanthin dirhamnoside.

    Science.gov (United States)

    Asker, Dalal; Awad, Tarek S; Beppu, Teruhiko; Ueda, Kenji

    2012-01-01

    Astaxanthin is a red ketocarotenoid that exhibits extraordinary health-promoting activities such as antioxidant, anti-inflammatory, antitumor, and immune booster. The recent discovery of the beneficial roles of astaxanthin against many degenerative diseases such as cancers, heart diseases, and exercise-induced fatigue has raised its market demand as a nutraceutical and medicinal ingredient in aquaculture, food, and pharmaceutical industries. To satisfy the growing demand for this high-value nutraceuticals ingredient and consumer interest in natural products, many research efforts are being made to discover novel microbial producers with effective biotechnological production of astaxanthin. Using a rapid screening method based on 16S rRNA gene, and effective HPLC-Diodearray-MS methods for carotenoids analysis, we succeeded to isolate a unique astaxanthin-producing bacterium (strain TDMA-17(T)) that belongs to the family Sphingomonadaceae (Asker et al., Appl Microbiol Biotechnol 77: 383-392, 2007). In this chapter, we provide a detailed description of effective HPLC-Diodearray-MS methods for rapid analysis and identification of the carotenoids produced by strain TDMA-17(T). We also describe the methods of isolation and identification for a novel bacterial carotenoid (astaxanthin derivative), a major carotenoid that is produced by strain TDMA-17(T). Finally, we describe the polyphasic taxonomic analysis of strain TDMA-17(T) and the description of a novel species belonging to genus Sphingomonas.

  6. MODELING OF MIXED CHEMOSTAT CULTURES OF AN AEROBIC BACTERIUM, COMAMONAS-TESTOSTERONI, AND AN ANAEROBIC BACTERIUM, VEILLONELLA-ALCALESCENS - COMPARISON WITH EXPERIMENTAL-DATA

    NARCIS (Netherlands)

    GERRITSE, J; SCHUT, F; GOTTSCHAL, JC

    A mathematical model of mixed chemostat cultures of the obligately aerobic bacterium Comamonas testosteroni and the anaerobic bacterium Veillonella alcalescens grown under dual limitation Of L-lactate and oxygen was constructed. The model was based on Michaelis-Menten-type kinetics for the

  7. Salt-inducible promoter derivable from a lactic acid bacterium, and its use in a lactic acid bacterium for production of a desired protein

    NARCIS (Netherlands)

    Sanders, Jan Willem; Kok, Jan; Venema, Gerard; Ledeboer, Adrianus Marinus

    1998-01-01

    The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a

  8. Beneficial effect of Curcumin in Letrozole induced polycystic ovary syndrome

    Directory of Open Access Journals (Sweden)

    P. Sushma Reddy

    2016-04-01

    Conclusion: Curcumin showed beneficial effects in Letrozole induced PCOS in female Wistar rats. Its effect was comparable to that of Clomiphene citrate, most widely used treatment for ovulation induction in PCOS condition.

  9. Pharmacological and other beneficial effects of anti- nutritional ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... Key words: Pharmacological, beneficial effects, anti-nutritional factors, plants. INTRODUCTION ...... Rankin SM, DeWhalley CV, Hoult S, Jessup W, Willins GM, Collard J, .... saponins from alfalfa on weeds and wheat. Bot. Bull ...

  10. Recycled industrial and construction waste for mutual beneficial use.

    Science.gov (United States)

    2016-08-01

    Instead of going to landfills, certain waste materials from industry and building construction can be recycled in transportation infrastructure projects, such as roadway paving. The beneficial use of waste materials in the construction of transportat...

  11. Chitin utilization by the insect-transmitted bacterium Xylella fastidiosa.

    Science.gov (United States)

    Killiny, Nabil; Prado, Simone S; Almeida, Rodrigo P P

    2010-09-01

    Xylella fastidiosa is an insect-borne bacterium that colonizes xylem vessels of a large number of host plants, including several crops of economic importance. Chitin is a polysaccharide present in the cuticle of leafhopper vectors of X. fastidiosa and may serve as a carbon source for this bacterium. Biological assays showed that X. fastidiosa reached larger populations in the presence of chitin. Additionally, chitin induced phenotypic changes in this bacterium, notably increasing adhesiveness. Quantitative PCR assays indicated transcriptional changes in the presence of chitin, and an enzymatic assay demonstrated chitinolytic activity by X. fastidiosa. An ortholog of the chitinase A gene (chiA) was identified in the X. fastidiosa genome. The in silico analysis revealed that the open reading frame of chiA encodes a protein of 351 amino acids with an estimated molecular mass of 40 kDa. chiA is in a locus that consists of genes implicated in polysaccharide degradation. Moreover, this locus was also found in the genomes of closely related bacteria in the genus Xanthomonas, which are plant but not insect associated. X. fastidiosa degraded chitin when grown on a solid chitin-yeast extract-agar medium and grew in liquid medium with chitin as the sole carbon source; ChiA was also determined to be secreted. The gene encoding ChiA was cloned into Escherichia coli, and endochitinase activity was detected in the transformant, showing that the gene is functional and involved in chitin degradation. The results suggest that X. fastidiosa may use its vectors' foregut surface as a carbon source. In addition, chitin may trigger X. fastidiosa's gene regulation and biofilm formation within vectors. Further work is necessary to characterize the role of chitin and its utilization in X. fastidiosa.

  12. Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense.

    Science.gov (United States)

    Loehr, Johannes; Pfeiffer, Daniel; Schüler, Dirk; Fischer, Thomas M

    2016-04-21

    Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film. The successful guidance of the bacteria depends on the right balance between motility and the magnetic moment of the magnetosome chain.

  13. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  14. Characterizing the host and symbiont proteomes in the association between the Bobtail squid, Euprymna scolopes, and the bacterium, Vibrio fischeri.

    Directory of Open Access Journals (Sweden)

    Tyler R Schleicher

    Full Text Available The beneficial symbiosis between the Hawaiian bobtail squid, Euprymna scolopes, and the bioluminescent bacterium, Vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. Colonization of the squid light organ by V. fischeri begins a lifelong association with a regulated daily rhythm. Each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial cells. We analyzed the host and symbiont proteomes of adult squid exudate and surrounding light organ epithelial tissue using 1D- and 2D-polyacrylamide gel electrophoresis and multidimensional protein identification technology (MudPIT in an effort to understand the contribution of both partners to the maintenance of this association. These proteomic analyses putatively identified 1581 unique proteins, 870 proteins originating from the symbiont and 711 from the host. Identified host proteins indicate a role of the innate immune system and reactive oxygen species (ROS in regulating the symbiosis. Symbiont proteins detected enhance our understanding of the role of quorum sensing, two-component signaling, motility, and detoxification of ROS and reactive nitrogen species (RNS inside the light organ. This study offers the first proteomic analysis of the symbiotic microenvironment of the adult light organ and provides the identification of proteins important to the regulation of this beneficial association.

  15. Aislamiento e identificación de cepas de Azospirillum sp. y evaluación de su capacidad para suplir las necesidades de nitrógeno en el cultivo de maíz (Zea mays) semihidroponico con dos sustratos diferentes bajo invernadero. Quito, Cayambe, Ecuador 2011.

    OpenAIRE

    Reyes Campaña, Alex Ramiro

    2011-01-01

    The corn, (Zea mays) L. is a basic crop in ecuadorian agriculture, which is why the search for environmentally friendly nitrogen fertilization of low cost doesn’t cease to be important. One of these options is the use of bio-fertilizers, for which the nitrogen fixing bacteria Azospirillum sp. can be used. The objective of this work is to isolate and identify Azospirillum sp. stumps, and evaluate its capacity to provide the nitrogen’s needs in the semi-hydroponic crop, , (Zea mays) L. withi...

  16. EFECT OF THE INOCULATION OF Rhodococcus fascians AND Azospirillum halopraeferens IN GERMINATION OF PALO FIERRO (Olneya tesota A. Gray UNDER GREENHOUSE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Edgar Omar Rueda Puente

    2017-05-01

    Full Text Available The growth-promoting bacteria in plants (BGPB are a group of different species of bacteria can increase plant growth and productivity. Which can benefit plants through their own bacterial metabolism (phosphate solubilizing, producing hormones or fixing nitrogen. At present, desertification is a growing phenomenon worldwide, afforestation is one of the common solutions to combat this problem. Trees for reforestation are initially grown in greenhouses or nurseries. Among numerous reforestation practices, there is an alternative that inoculation with PGPB. Is a forest species that is endemic Olneya tesota Sonoran Desert, which is in danger of extinction. The objective was to evaluate the effect of bacteria growth promoter in plants with Rhodococcuis fascians and Azospirillum halopraeferens on germination and emergence of Ironwood under four salt concentrations (0, 0.25, 0.5 and 0.75 M NaCl under greenhouse conditions. Were obtained ironwood seeds in the region of Santa Ana, Sonora. Under greenhouse conditions was evaluated emergence percentage, germination rate, height, plant root length, fresh and dry weight of plant, number of bacterial cells attached to the root system, fresh and dry weight of the root. The results indicate that the germination percentage and other variables evaluated decreased as salinity increases. However, these changed positively to inoculation with bacteria R. fascians and A. halopraeferens.

  17. Characterization of Cell Surface and EPS Remodeling of Azospirillum brasilense Chemotaxis-like 1 Signal Transduction Pathway mutants by Atomic Force Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Billings, Amanda N [ORNL; Siuti, Piro [ORNL; Bible, Amber [University of Tennessee, Knoxville (UTK); Alexandre, Gladys [University of Tennessee, Knoxville (UTK); Retterer, Scott T [ORNL; Doktycz, Mitchel John [ORNL; Morrell-Falvey, Jennifer L [ORNL

    2011-01-01

    To compete in complex microbial communities, bacteria must quickly sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the modulation of multiple cellular responses, including motility, EPS production, and cell-to-cell interactions. Recently, the Che1 chemotaxis-like pathway from Azospirillum brasilense was shown to modulate flocculation. In A. brasilense, cell surface properties, including EPS production, are thought to play a direct role in promoting flocculation. Using atomic force microscopy (AFM), we have detected distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains that are absent in the wild type strain. Whereas the wild type strain produces a smooth mucosal extracellular matrix, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition and lectin-binding assays suggest that the composition of EPS components in the extracellular matrix differs between the cheA1 and cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that mutations in the Che1 pathway that result in increased flocculation are correlated with distinctive changes in the extracellular matrix structure produced by the mutants, including likely changes in the EPS structure and/or composition.

  18. Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense

    International Nuclear Information System (INIS)

    Sotomaior, P.; Araújo, L.M.; Nishikawa, C.Y.; Huergo, L.F.; Monteiro, R.A.; Pedrosa, F.O.; Chubatsu, L.S.; Souza, E.M.

    2012-01-01

    Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate

  19. [Genome Rearrangements in Azospirillum brasilense Sp7 with the Involvement of the Plasmid pRhico and the Prophage phiAb-Cd].

    Science.gov (United States)

    Katsy, E I; Petrova, L P

    2015-12-01

    Alphaproteobacteria of the species Azospirillum brasilense have a multicomponent genome that undergoes frequent spontaneous rearrangements, yielding changes in the plasmid profiles of strains. Specifically, variants (Cd, Sp7.K2, Sp7.1, Sp7.4, Sp7.8, etc.) of the type strainA. brasilense Sp7 that had lost a 115-MDa plasmid were previously selected. In many of them, the molecular weight of a 90-MDa plasmid (p90 or pRhico), which is a kind of "depot" for glycopolymer biosynthesis genes, increased. In this study, a collection of primers was designed to the plasmid pRhico and to the DNA of prophage phiAb-Cd integrated in it. The use ofthese primers in polymerase chain reactions allowed the detection of the probable excision of phiAb-Cd phage from the DNA of A. brasilense variants Sp7.4 and Sp7.8 and other alterations of the pRhico structure in A. brasilense strains Cd, Sp7.K2, and Sp7.8. The developed primers and PCR conditions may be recoin mended for primary analysis of spontaneous plasmid rearrangements in A. brasilense Sp7 and related strains.

  20. Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense.

    Science.gov (United States)

    Sotomaior, P; Araújo, L M; Nishikawa, C Y; Huergo, L F; Monteiro, R A; Pedrosa, F O; Chubatsu, L S; Souza, E M

    2012-12-01

    Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.

  1. The ntrB and ntrC Genes Are Involved in the Regulation of Poly-3-Hydroxybutyrate Biosynthesis by Ammonia in Azospirillum brasilense Sp7

    Science.gov (United States)

    Sun, Jun; Peng, Xuan; Van Impe, Jan; Vanderleyden, Jos

    2000-01-01

    Azospirillum brasilense Sp7 and its ntrA (rpoN), ntrBC, and ntrC mutants have been evaluated for their capabilities of poly-3-hydroxybutyrate (PHB) accumulation in media with high and low ammonia concentrations. It was observed that the ntrBC and ntrC mutants can produce PHB in both low- and high-C/N-ratio media, while no significant PHB production was observed for the wild type or the ntrA mutant in low-C/N-ratio media. Further investigation by fermentation analysis indicated that the ntrBC and ntrC mutants were able to grow and accumulate PHB simultaneously in the presence of a high concentration of ammonia in the medium, while little PHB was produced in the wild type and ntrA (rpoN) mutant during active growth phase. These results provide the first genetic evidence that the ntrB and ntrC genes are involved in the regulation of PHB synthesis by ammonia in A. brasilense Sp7. PMID:10618211

  2. Early plant growth and biochemical responses induced by Azospirillum brasilense Sp245 lipopolysaccharides in wheat (Triticum aestivum L.) seedlings are attenuated by procyanidin B2.

    Science.gov (United States)

    Vallejo-Ochoa, Juan; López-Marmolejo, Mariel; Hernández-Esquivel, Alma Alejandra; Méndez-Gómez, Manuel; Suárez-Soria, Laura Nicolasa; Castro-Mercado, Elda; García-Pineda, Ernesto

    2018-03-01

    This study analyzes the effects of procyanidin B2 on early wheat plant growth and plant biochemical responses promoted by lipopolysaccharides (LPS) derived from the rhizobacteria Azospirillum brasilense Sp245. Measurements of leaf, root length, fresh weight, and dry weight showed in vitro plant growth stimulation 4 days after treatment with A. brasilense as well as LPS. Superoxide anion (O 2 ·- ) and hydrogen peroxide (H 2 O 2 ) levels increased in seedling roots treated with LPS (100 μg mL -1 ). The chlorophyll content in leaf decreased while the starch content increased 24 h after treatment in seedling roots. The LPS treatment induced a high increase in total peroxidase (POX) (EC 1.11.1.7) activity and ionically bound cell wall POX content in roots, when compared to respective controls. Early plant growth and biochemical responses observed in wheat seedlings treated with LPS were inhibited by the addition of procyanidin B2 (5 μg mL -1 ), a B type proanthocyanidin (PAC), plant-derived polyphenolic compound with binding properties of LPS. All results suggest first that the ionically bound cell wall POX enzymes could be a molecular target of A. brasilense LPS, and second that the recognition or association of LPS by plant cells is required to activate plant responses. This last event could play a critical role during plant growth regulation by A. brasilense LPS.

  3. Development of alginate-based aggregate inoculants of Methylobacterium sp. and Azospirillum brasilense tested under in vitro conditions to promote plant growth.

    Science.gov (United States)

    Joe, M M; Saravanan, V S; Islam, M R; Sa, T

    2014-02-01

    To develop co-aggregated bacterial inoculant comprising of Methylobacterium oryzae CBMB20/Methylobacterium suomiense CBMB120 strains with Azospirillum brasilense (CW903) strain and testing their efficiency as inoculants for plant growth promotion (PGP). Biofilm formation and co-aggregation efficiency was studied between A. brasilense CW903 and methylobacterial strains M. oryzae CBMB20 and M. suomiense CBMB120. Survival and release of these co-aggregated bacterial strains entrapped in alginate beads were assessed. PGP attributes of the co-aggregated bacterial inoculant were tested in tomato plants under water-stressed conditions. Results suggest that the biofilm formation efficiency of the CBMB20 and CBMB120 strains increased by 15 and 34%, respectively, when co-cultivated with CW903. Co-aggregation with CW903 enhanced the survivability of CBMB20 strain in alginate beads. Water stress index score showed least stress index in plants inoculated with CW903 and CBMB20 strains maintained as a co-aggregated inoculant. This study reports the development of co-aggregated cell inoculants containing M. oryzae CBMB20 and A. brasilense CW903 strains conferred better shelf life and stress abatement in inoculated tomato plants. These findings could be extended to other PGP bacterial species to develop multigeneric bioinoculants with multiple benefits for various crops. © 2013 The Society for Applied Microbiology.

  4. Influence of tryptophan and indole-3-acetic acid on starch accumulation in the synthetic mutualistic Chlorella sorokiniana-Azospirillum brasilense system under heterotrophic conditions.

    Science.gov (United States)

    Palacios, Oskar A; Choix, Francisco J; Bashan, Yoav; de-Bashan, Luz E

    2016-06-01

    This study measured the relations between tryptophan production, the phytohormone indole-3-acetic acid (IAA) and the metabolism and accumulation of starch during synthetic mutualism between the microalgae Chlorella sorokiniana and the microalgae growth-promoting bacteria Azospirillum brasilense, created by co-immobilization in alginate beads. Experiments used two wild-type A. brasilense strains (Cd and Sp6) and an IAA-attenuated mutant (SpM7918) grown under nitrogen-replete and nitrogen-starved conditions tested under dark, heterotrophic and aerobic growth conditions. Under all incubating conditions, C. sorokiniana, but not A. brasilense, produced tryptophan. A significant correlation between IAA-production by A. brasilense and starch accumulation in C. sorokiniana was found, since the IAA-attenuated mutant was not producing increased starch levels. The highest ADP-glucose pyrophosphorylase (AGPase) activity, starch content and glucose uptake were found during the interaction of A. brasilense wild type strains with the microalgae. When the microalgae were grown alone, they produced only small amounts of starch. Supplementation with synthetic IAA to C. sorokiniana grown alone enhanced the above parameters, but only transiently. Activity of α-amylase decreased under nitrogen-replete conditions, but increased under nitrogen-starved conditions. In summary, this study demonstrated that, during synthetic mutualism, the exchange of tryptophan and IAA between the partners is a mechanism that governs several changes in starch metabolism of C. sorokiniana, yielding an increase in starch content. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  5. Regulation of expression and biochemical characterization of a beta-class carbonic anhydrase from the plant growth-promoting rhizobacterium, Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kaur, Simarjot; Mishra, Mukti Nath; Tripathi, Anil K

    2009-10-01

    Carbonic anhydrase (CA; [EC 4.2.1.1]) is a ubiquitous enzyme catalysing the reversible hydration of CO(2) to bicarbonate, a reaction that supports various biochemical and physiological functions. Genome analysis of Azospirillum brasilense, a nonphotosynthetic, nitrogen-fixing, rhizobacterium, revealed an ORF with homology to beta-class carbonic anhydrases (CAs). Biochemical characteristics of the beta-class CA of A. brasilense, analysed after cloning the gene (designated as bca), overexpressing in Escherichia coli and purifying the protein by affinity purification, revealed that the native recombinant enzyme is a homotetramer, inhibited by the known CA inhibitors. CA activity in A. brasilense cell extracts, reverse transcriptase (RT)-PCR and Western blot analyses showed that bca was constitutively expressed under aerobic conditions. Lower beta-galactosidase activity in A. brasilense cells harbouring bca promoter: lacZ fusion during the stationary phase or during growth on 3% CO(2) enriched air or at acidic pH indicated that the transcription of bca was downregulated by the stationary phase, elevated CO(2) levels and acidic pH conditions. These observations were also supported by RT-PCR analysis. Thus, beta-CA in A. brasilense seems to be required for scavenging CO(2) from the ambient air and the requirement of CO(2) hydration seems to be higher for the cultures growing exponentially at neutral to alkaline pH.

  6. Characterization of cell surface and extracellular matrix remodeling of Azospirillum brasilense chemotaxis-like 1 signal transduction pathway mutants by atomic force microscopy.

    Science.gov (United States)

    Edwards, Amanda Nicole; Siuti, Piro; Bible, Amber N; Alexandre, Gladys; Retterer, Scott T; Doktycz, Mitchel J; Morrell-Falvey, Jennifer L

    2011-01-01

    To compete in complex microbial communities, bacteria must sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the regulation of multiple behaviors in response to changes in the environment, including motility patterns, exopolysaccharide production, and cell-to-cell interactions. In Azospirillum brasilense, cell surface properties, including exopolysaccharide production, are thought to play a direct role in promoting flocculation. Recently, the Che1 chemotaxis-like pathway from A. brasilense was shown to modulate flocculation, suggesting an associated modulation of cell surface properties. Using atomic force microscopy, distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains were detected. Whereas the wild-type strain produces a smooth mucosal extracellular matrix after 24 h, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition, lectin-binding assays, and comparison of lipopolysaccharides profiles suggest that the extracellular matrix differs between the cheA1 and the cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that disruption of the Che1 pathway is correlated with distinctive changes in the extracellular matrix, which likely result from changes in surface polysaccharides structure and/or composition. FEMS Microbiology Letters © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. No claim to original US government works.

  7. Enhanced performance of the microalga Chlorella sorokiniana remotely induced by the plant growth-promoting bacteria Azospirillum brasilense and Bacillus pumilus

    Science.gov (United States)

    Amavizca, Edgar; Bashan, Yoav; Ryu, Choong-Min; Farag, Mohamed A.; Bebout, Brad M.; de-Bashan, Luz E.

    2017-01-01

    Remote effects (occurring without physical contact) of two plant growth-promoting bacteria (PGPB) Azospirillum brasilense Cd and Bacilus pumilus ES4 on growth of the green microalga Chlorella sorokiniana UTEX 2714 were studied. The two PGPB remotely enhanced the growth of the microalga, up to six-fold, and its cell volume by about three-fold. In addition to phenotypic changes, both bacteria remotely induced increases in the amounts of total lipids, total carbohydrates, and chlorophyll a in the cells of the microalga, indicating an alteration of the microalga’s physiology. The two bacteria produced large amounts of volatile compounds, including CO2, and the known plant growth-promoting volatile 2,3-butanediol and acetoin. Several other volatiles having biological functions in other organisms, as well as numerous volatile compounds with undefined biological roles, were detected. Together, these bacteria-derived volatiles can positively affect growth and metabolic parameters in green microalgae without physical attachment of the bacteria to the microalgae. This is a new paradigm on how PGPB promote growth of microalgae which may serve to improve performance of Chlorella spp. for biotechnological applications. PMID:28145473

  8. Characterization of cell surface and extracellular matrix remodeling of Azospirillum brasilense chemotaxis-like 1 signal transduction pathway mutants by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Doktycz, Mitchel John [ORNL; Morrell-Falvey, Jennifer L [ORNL

    2011-01-01

    To compete in complex microbial communities, bacteria must sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the regulation of multiple behaviors in response to changes in the environment, including motility patterns, exopolysaccharide production, and cell-to-cell interactions. In Azospirillum brasilense, cell surface properties, including exopolysaccharide production, are thought to play a direct role in promoting flocculation. Recently, the Che1 chemotaxis-like pathway from A. brasilense was shown to modulate flocculation, suggesting an associated modulation of cell surface properties. Using atomic force microscopy, distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains were detected. Whereas the wild-type strain produces a smooth mucosal extracellular matrix after 24 h, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition, lectin-binding assays, and comparison of lipopolysaccharides profiles suggest that the extracellular matrix differs between the cheA1 and the cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that disruption of the Che1 pathway is correlated with distinctive changes in the extracellular matrix, which likely result from changes in surface polysaccharides structure and/or composition.

  9. Positive effect of reduced aeration rate on growth and stereospecificity of DL-malic acid consumption by Azospirillum brasilense: improving the shelf life of a liquid inoculant formulation.

    Science.gov (United States)

    Carrasco-Espinosa, Karen; García-Cabrera, Ramsés I; Bedoya-López, Andrea; Trujillo-Roldán, Mauricio A; Valdez-Cruz, Norma A

    2015-02-10

    Azospirillum brasilense has significance as a growth promoter in plants of commercial interest. Two industrial native strains (Start and Calf), used as a part of an inoculant formulation in Mexico during the last 15 years, were incubated in laboratory-scale pneumatic bioreactors at different aeration rates. In both strains, the positive effect of decreased aeration was observed. At the lowest (0.1 vvm, air volume/liquid volume×minute), the highest biomass were obtained for Calf (7.8 × 10(10)CFU/ml), and Start (2.9 × 10(9)CFU/ml). These were higher in one magnitude order compared to cultures carried out at 0.5 vvm, and two compared to those at 1.0 vvm. At lower aeration, both stereoisomeric forms of malic acid were consumed, but at higher aeration, just L-malate was consumed. A reduction in aeration allows an increase of the shelf life and the microorganism saved higher concentrations of polyhydroxybutyrate. The selected fermentation conditions are closely related to those prevalent in large-scale bioreactors and offer the possibility of achieving high biomass titles with high shelf life at a reduced costs, due to the complete use of a carbon source at low aeration of a low cost raw material as DL-malic acid mixture in comparison with the L-malic acid stereoisomer. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense

    Energy Technology Data Exchange (ETDEWEB)

    Sotomaior, P.; Araújo, L.M.; Nishikawa, C.Y.; Huergo, L.F.; Monteiro, R.A.; Pedrosa, F.O.; Chubatsu, L.S.; Souza, E.M. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil)

    2012-09-21

    Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.

  11. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  12. Evolutionary transitions between beneficial and phytopathogenic Rhodococcus challenge disease management.

    Science.gov (United States)

    Savory, Elizabeth A; Fuller, Skylar L; Weisberg, Alexandra J; Thomas, William J; Gordon, Michael I; Stevens, Danielle M; Creason, Allison L; Belcher, Michael S; Serdani, Maryna; Wiseman, Michele S; Grünwald, Niklaus J; Putnam, Melodie L; Chang, Jeff H

    2017-12-12

    Understanding how bacteria affect plant health is crucial for developing sustainable crop production systems. We coupled ecological sampling and genome sequencing to characterize the population genetic history of Rhodococcus and the distribution patterns of virulence plasmids in isolates from nurseries. Analysis of chromosome sequences shows that plants host multiple lineages of Rhodococcus , and suggested that these bacteria are transmitted due to independent introductions, reservoir populations, and point source outbreaks. We demonstrate that isolates lacking virulence genes promote beneficial plant growth, and that the acquisition of a virulence plasmid is sufficient to transition beneficial symbionts to phytopathogens. This evolutionary transition, along with the distribution patterns of plasmids, reveals the impact of horizontal gene transfer in rapidly generating new pathogenic lineages and provides an alternative explanation for pathogen transmission patterns. Results also uncovered a misdiagnosed epidemic that implicated beneficial Rhodococcus bacteria as pathogens of pistachio. The misdiagnosis perpetuated the unnecessary removal of trees and exacerbated economic losses.

  13. Beneficial reuse of US DOE Radioactive scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Motl, G.P.

    1995-01-19

    The US Department of Energy (DOE) has more than 2.5 million tons of radioactive scrap metal (RSM) that is either in inventory or expected to be generated over the next 25 years as major facilities within the weapons complex are decommissioned. Since much of this metal cannot be decontaminated easily, past practice has been to either retain this material in inventory or ship it to DOE disposal sites for burial. In an attempt to conserve natural resources and to avoid burial of this material at DOE disposal sites, options are now being explored to ``beneficially reuse`` this material. Under the beneficial reuse concept, RSM that cannot be decontaminated and free released is used in applications where the inherent contamination is not a detriment to its end use. This paper describes initiatives currently in progress in the United States that support the DOE beneficial reuse concept.

  14. Beneficial reuse of US DOE Radioactive scrap metal

    International Nuclear Information System (INIS)

    Motl, G.P.

    1995-01-01

    The US Department of Energy (DOE) has more than 2.5 million tons of radioactive scrap metal (RSM) that is either in inventory or expected to be generated over the next 25 years as major facilities within the weapons complex are decommissioned. Since much of this metal cannot be decontaminated easily, past practice has been to either retain this material in inventory or ship it to DOE disposal sites for burial. In an attempt to conserve natural resources and to avoid burial of this material at DOE disposal sites, options are now being explored to ''beneficially reuse'' this material. Under the beneficial reuse concept, RSM that cannot be decontaminated and free released is used in applications where the inherent contamination is not a detriment to its end use. This paper describes initiatives currently in progress in the United States that support the DOE beneficial reuse concept

  15. Combustion characterization of beneficiated coal-based fuels

    Energy Technology Data Exchange (ETDEWEB)

    Chow, O.K.; Levasseur, A.A.

    1995-11-01

    The Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy is sponsoring the development of advanced coal-cleaning technologies aimed at expanding the use of the nation`s vast coal reserves in an environmentally and economically acceptable manner. Because of the lack of practical experience with deeply beneficiated coal-based fuels, PETC has contracted Combustion Engineering, Inc. to perform a multi-year project on `Combustion Characterization of Beneficiated Coal-Based Fuels.` The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of Beneficiated Coal-Based Fuels (BCs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs.

  16. Bioaugmentation with endophytic bacterium E6S homologous to Achromobacter piechaudii enhances metal rhizoaccumulation in host Sedum plumbizincicola

    Directory of Open Access Journals (Sweden)

    Ying eMa

    2016-02-01

    Full Text Available Application of hyperaccumulator–endophyte symbiotic systems is a potential approach to improve phytoremediation efficiency, since some beneficial endophytic bacteria are able to detoxify heavy metals, alter metal solubility in soil and facilitate plant growth. The objective of this study was to isolate multi-metal resistant and plant beneficial endophytic bacteria and to evaluate their role in enhancing plant growth and metal accumulation/translocation. The metal resistant endophytic bacterial strain E6S was isolated from stems of the Zn/Cd hyperaccumulator plant Sedum plumbizincicola growing in metalliferous mine soils using Dworkin and Foster salts minimal agar medium with 1-aminocyclopropane-1-carboxylate (ACC as the sole nitrogen source, and identified as homologous to Achromobacter piechaudii based on morphological and biochemical characteristics, partial 16S rDNA sequence and phylogenetic analysis. Strain E6S showed high level of resistance to various metals (Cd, Zn and Pb. Besides utilizing ACC, strain E6S exhibited plant beneficial traits, such as solubilization of phosphate and production of indole-3-acetic acid. Inoculation with E6S significantly increased the bioavailability of Cd, Zn and Pb in soil. In addition, bacterial cells bound considerable amounts of metal ions in the following order: Zn ˃ Cd ˃ Pb. Inoculation of E6S significantly stimulated plant biomass, uptake and bioaccumulation of Cd, Zn and Pb. However, E6S greatly reduced the root to shoot translocation of Cd and Zn, indicating that bacterial inoculation assisted the host plant to uptake and store heavy metals in its root system. Inoculation with the endophytic bacterium E6S homologous to A. piechaudii can improve phytostabilization of metalliferous soils due to its effective ability to enhance in situ metal rhizoaccumulation in plants.

  17. Competitive Interactions in Mixed-Species Biofilms Containing the Marine Bacterium Pseudoalteromonas tunicata

    Science.gov (United States)

    Rao, Dhana; Webb, Jeremy S.; Kjelleberg, Staffan

    2005-01-01

    Pseudoalteromonas tunicata is a biofilm-forming marine bacterium that is often found in association with the surface of eukaryotic organisms. It produces a range of extracellular inhibitory compounds, including an antibacterial protein (AlpP) thought to be beneficial for P. tunicata during competition for space and nutrients on surfaces. As part of our studies on the interactions between P. tunicata and the epiphytic bacterial community on the marine plant Ulva lactuca, we investigated the hypothesis that P. tunicata is a superior competitor compared with other bacteria isolated from the plant. A number of U. lactuca bacterial isolates were (i) identified by 16S rRNA gene sequencing, (ii) characterized for the production of or sensitivity to extracellular antibacterial proteins, and (iii) labeled with a fluorescent color tag (either the red fluorescent protein DsRed or green fluorescent protein). We then grew single- and mixed-species bacterial biofilms containing P. tunicata in glass flow cell reactors. In pure culture, all the marine isolates formed biofilms containing microcolony structures within 72 h. However, in mixed-species biofilms, P. tunicata removed the competing strain unless its competitor was relatively insensitive to AlpP (Pseudoalteromonas gracilis) or produced strong inhibitory activity against P. tunicata (Roseobacter gallaeciensis). Moreover, biofilm studies conducted with an AlpP− mutant of P. tunicata indicated that the mutant was less competitive when it was introduced into preestablished biofilms, suggesting that AlpP has a role during competitive biofilm formation. When single-species biofilms were allowed to form microcolonies before the introduction of a competitor, these microcolonies coexisted with P. tunicata for extended periods of time before they were removed. Two marine bacteria (R. gallaeciensis and P. tunicata) were superior competitors in this study. Our data suggest that this dominance can be attributed to the ability of

  18. Do dorsal raphe 5-HT neurons encode "beneficialness"?

    Science.gov (United States)

    Luo, Minmin; Li, Yi; Zhong, Weixin

    2016-11-01

    The neurotransmitter serotonin (5-hydroxytryptamine; 5-HT) affects numerous behavioral and physiological processes. Drugs that alter 5-HT signaling treat several major psychiatric disorders and may lead to widespread abuse. The dorsal raphe nucleus (DRN) in the midbrain provides a majority of 5-HT for the forebrain. The importance of 5-HT signaling propels the search for a general theoretical framework under which the diverse functions of the DRN 5-HT neurons can be interpreted and additional therapeutic solutions may be developed. However, experimental data so far support several seeming irreconcilable theories, suggesting that 5-HT neurons mediate behavioral inhibition, aversive processing, or reward signaling. Here, we review recent progresses and propose that DRN 5-HT neurons encode "beneficialness" - how beneficial the current environmental context represents for an individual. Specifically, we speculate that the activity of these neurons reflects the possible net benefit of the current context as determined by p·R-C, in which p indicates reward probability, R the reward value, and C the cost. Through the widespread projections of these neurons to the forebrain, the beneficialness signal may reconfigure neural circuits to bias perception, boost positive emotions, and switch behavioral choices. The "beneficialness" hypothesis can explain many conflicting observations, and at the same time raises new questions. We suggest additional experiments that will help elucidate the exact computational functions of the DRN 5-HT neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Factitious foods to reduce production costs of beneficial insects

    Science.gov (United States)

    This article reports the use of factitious foods such as Tenebrio molitor pupa, E. kuehniella eggs, Ephestia eggs, and or Artemia franciscana eggs for the rearing of beneficial insect such as Podisus maculiventris, spined soldier bug and several ladybird predators belonging to the Coccinellidae fam...

  20. Beneficial Insects and Insect Pollinators on Milkweed in South Georgia

    Science.gov (United States)

    Insect pollinators are essential for the reproduction of more than two-thirds of the world’s crops, and beneficial insects play an important role in managing pest insects in agricultural farmscapes. These insects depend on nectar for their survival in these farmscapes. The flowers of tropical milkwe...

  1. Acceptance for Beneficial Use Pumping Instrumentation and Control Skid ''M''

    International Nuclear Information System (INIS)

    KOCH, M.R.

    2000-01-01

    This document is a Final Acceptance for Beneficial Use (ABU) for the readiness of Pumping Instrumentation and Control (PIC) skid ''M''. All the testing and documentation for PIC skid ''M'' is completed and the skid is ready for use in the field for pumping of tank U-102

  2. When are enhanced relationship tax compliance programs mutually beneficial?

    NARCIS (Netherlands)

    De Simone, L.; Sansing, R.; Seidman, J.K.

    2013-01-01

    This study investigates the circumstances under which “enhanced relationship” tax-compliance programs are mutually beneficial to taxpayers and tax authorities, as well as how these benefits are shared. We develop a model of taxpayer and tax authority behavior inside and outside of an enhanced

  3. Research Priorities for Robust and Beneficial Artificial Intelligence

    OpenAIRE

    Russell, Stuart; Dewey, Daniel; Tegmark, Max

    2015-01-01

    Success in the quest for artificial intelligence has the potential to bring unprecedented benefits to humanity, and it is therefore worthwhile to investigate how to maximize these benefits while avoiding potential pitfalls. This article gives numerous examples (which should by no means be construed as an exhaustive list) of such worthwhile research aimed at ensuring that AI remains robust and beneficial.

  4. Nebivolol might be Beneficial in Osteoporosis Treatment: A Hypothesis

    African Journals Online (AJOL)

    There are some studies conducted in humans and animal models which have shown that NO is an important regulator of bone metabolism. However, oxidative stress and antioxidant systems may play important roles in the pathogenesis of osteoporosis. In this paper, we hypothesized that nebivolol may have beneficial ...

  5. THE BENEFICIAL EFFECTS OF SPORT ON ANXIETY AND DEPRESSION

    Directory of Open Access Journals (Sweden)

    Francesco Perrotta

    2010-08-01

    Full Text Available It is well established that exercise increases energy levels and mood state. At least 20 published studies, indicate a link between physical activity and signs of prosperity. There is much medical evidence showing the beneficial effects of exercise on cardiovascular disease, obesity and diabetes. Currently there is growing interest to see ifphysical activity can also improve symptoms of mental illness

  6. The non-target impact of spinosyns on beneficial arthropods.

    Science.gov (United States)

    Biondi, Antonio; Mommaerts, Veerle; Smagghe, Guy; Viñuela, Elisa; Zappalà, Lucia; Desneux, Nicolas

    2012-12-01

    Spinosyn-based products, mostly spinosad, have been widely recommended by extension specialists and agribusiness companies; consequently, they have been used to control various pests in many different cropping systems. Following the worldwide adoption of spinosad-based products for integrated and organic farming, an increasing number of ecotoxicological studies have been published in the past 10 years. These studies are primarily related to the risk assessment of spinosad towards beneficial arthropods. This review takes into account recent data with the aim of (i) highlighting potentially adverse effects of spinosyns on beneficial arthropods (and hence on ecosystem services that they provide in agroecosystems), (ii) clarifying the range of methods used to address spinosyn side effects on biocontrol agents and pollinators in order to provide new insights for the development of more accurate bioassays, (iii) identifying pitfalls when analysing laboratory results to assess field risks and (iv) gaining increasing knowledge on side effects when using spinosad for integrated pest management (IPM) programmes and organic farming. For the first time, a thorough review of possible risks of spinosad and novel spinosyns (such as spinetoram) to beneficial arthropods (notably natural enemies and pollinators) is provided. The acute lethal effect and multiple sublethal effects have been identified in almost all arthropod groups studied. This review will help to optimise the future use of spinosad and new spinosyns in IPM programmes and for organic farming, notably by preventing the possible side effects of spinosyns on beneficial arthropods. Copyright © 2012 Society of Chemical Industry.

  7. A review on the beneficial aspects of food processing.

    NARCIS (Netherlands)

    Boekel, van M.A.J.S.; Fogliano, V.; Pellegrini, N.; Stanton, C.; Scholz, G.; Lalljie, S.P.D.; Somoza, V.; Knorr, D.; Rao Jasti, P.; Eisenbrand, G.

    2010-01-01

    The manuscript reviews beneficial aspects of food processing with main focus on cooking/heat treatment, including other food-processing techniques (e.g. fermentation). Benefits of thermal processing include inactivation of food-borne pathogens, natural toxins or other detrimental constituents,

  8. Hydrogen production by co-cultures of Lactobacillus and a photosynthetic bacterium, Rhodobacter sphaeroides RV

    Energy Technology Data Exchange (ETDEWEB)

    Asada, Yasuo; Ishimi, Katsuhiro [Department of General Education, College of Science and Technology, Nihon University, Narashinodai, Chiba 274-8501 (Japan); Tokumoto, Masaru; Aihara, Yasuyuki; Oku, Masayo; Kohno, Hideki [Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Izumi-cho, Chiba 275-8575 (Japan); Wakayama, Tatsuki; Miyake, Jun [Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, Nakoji, Amagasaki, Hyogo 661-0974 (Japan); Tomiyama, Masamitsu [Genetic Diversity Department, National Institute of Agrobiological Science, Tsukuba, Ibaraki 305-8602 (Japan)

    2006-09-15

    Hydrogen production with glucose by using co-immobilized cultures of a lactic acid bacterium, Lactobacillus delbrueckii NBRC13953, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. Glucose was converted to hydrogen gas in a yield of 7.1mol of hydrogen per mole of glucose at a maximum under illuminated conditions. (author)

  9. Isolation and characterization of Caldicellulosiruptor lactoaceticus sp. nov., an extremely thermophilic, cellulolytic, anaerobic bacterium

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Mathrani, Indra M.; Ahring, Birgitte Kiær

    1995-01-01

    An anaerobic, extremely thermophilic, cellulolytic, non-spore-forming bacterium, strain 6A, was isolated from an alkaline hot spring in Hverageroi, Iceland. The bacterium was non-motile, rod-shaped (1.5-3.5 x 0.7 mu m) and occurred singly, in pairs or in chains and stained gram-negative. The growth...

  10. Dense populations of a giant sulfur bacterium in Namibian shelf sediments

    DEFF Research Database (Denmark)

    Schulz, HN; Brinkhoff, T.; Ferdelman, TG

    1999-01-01

    A previously unknown giant sulfur bacterium is abundant in sediments underlying the oxygen minimum zone of the Benguela Current upwelling system. The bacterium has a spherical cell that exceeds by up to 100-fold the biovolume of the largest known prokaryotes. On the basis of 16S ribosomal DNA...

  11. Genome analysis of the anaerobic thermohalophilic bacterium Halothermothrix orenii.

    Directory of Open Access Journals (Sweden)

    Konstantinos Mavromatis

    Full Text Available Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  12. Genome analysis of the Anerobic Thermohalophilic bacterium Halothermothrix orenii

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Ivanova, Natalia; Anderson, Iain; Lykidis, Athanasios; Hooper, Sean D.; Sun, Hui; Kunin, Victor; Lapidus, Alla; Hugenholtz, Philip; Patel, Bharat; Kyrpides, Nikos C.

    2008-11-03

    Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  13. Growth of a Strictly Anaerobic Bacterium on Furfural (2-Furaldehyde)

    Science.gov (United States)

    Brune, Gerhard; Schoberth, Siegfried M.; Sahm, Hermann

    1983-01-01

    A strictly anaerobic bacterium was isolated from a continuous fermentor culture which converted the organic constituents of sulfite evaporator condensate to methane and carbon dioxide. Furfural is one of the major components of this condensate. This furfural isolate could degrade furfural as the sole source of carbon and energy in a defined mineral-vitamin-sulfate medium. Acetic acid was the major fermentation product. This organism could also use ethanol, lactate, pyruvate, or fumarate and contained cytochrome c3 and desulfoviridin. Except for furfural degradation, the characteristics of the furfural isolate were remarkably similar to those of the sulfate reducer Desulfovibrio gigas. The furfural isolate has been tentatively identified as Desulfovibrio sp. strain F-1. Images PMID:16346423

  14. A bacterium that degrades and assimilates poly(ethylene terephthalate).

    Science.gov (United States)

    Yoshida, Shosuke; Hiraga, Kazumi; Takehana, Toshihiko; Taniguchi, Ikuo; Yamaji, Hironao; Maeda, Yasuhito; Toyohara, Kiyotsuna; Miyamoto, Kenji; Kimura, Yoshiharu; Oda, Kohei

    2016-03-11

    Poly(ethylene terephthalate) (PET) is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern. Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy. By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source. When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol. Copyright © 2016, American Association for the Advancement of Science.

  15. The O-antigen structure of bacterium Comamonas aquatica CJG.

    Science.gov (United States)

    Wang, Xiqian; Kondakova, Anna N; Zhu, Yutong; Knirel, Yuriy A; Han, Aidong

    2017-11-01

    Genus Comamonas is a group of bacteria that are able to degrade a variety of environmental waste. Comamonas aquatica CJG (C. aquatica) in this genus is able to absorb low-density lipoprotein but not high-density lipoprotein of human serum. Using 1 H and 13 C NMR spectroscopy, we found that the O-polysaccharide (O-antigen) of this bacterium is comprised of a disaccharide repeat (O-unit) of d-glucose and 2-O-acetyl-l-rhamnose, which is shared by Serratia marcescens O6. The O-antigen gene cluster of C. aquatica, which is located between coaX and tnp4 genes, contains rhamnose synthesis genes, glycosyl and acetyl transferase genes, and ATP-binding cassette transporter genes, and therefore is consistent with the O-antigen structure determined here.

  16. Complete genome sequence of the photoautotrophic and bacteriochlorophyll e-synthesizing green sulfur bacterium Chlorobaculum limnaeum DSM 1677T

    DEFF Research Database (Denmark)

    Tank, Marcus; Liu, Zhenfeng; Frigaard, Niels-Ulrik

    2017-01-01

    Chlorobaculum limnaeum DSM 1677T is a mesophilic, brown-colored, chlorophototrophic green sulfur bacterium that produces bacteriochlorophyll e and the carotenoid isorenieratene as major pigments. This bacterium serves as a model organism in molecular research on photosynthesis, sulfur metabolism...

  17. Acceptance for Beneficial Use Pumping Instrumentation and Control Skid N

    International Nuclear Information System (INIS)

    KOCH, M.R.

    2000-01-01

    This is a final Acceptance for Beneficial Use (ABU) for Pumping and Instrumentation Control (PIC) skid ''N''. PIC skid ''N'' is ready for pumping tank U-109. All the testing and documentation has been completed as required on the AE3U checklist. This AE3U covers only the readiness of the PIC skid ''N''. Other U-farm preparations including dilution tank fabrication, portable exhauster readiness, leak detection, valve pit preparation, and the Operation Control Station readiness are not part of this ABU. PIC skid ''N'' is a new skid fabricated and tested at Site Fabrication Services. The skid controls the jet pump and monitors various instruments associated with the pumping operation. This monitoring includes leak detection along the waste transfer route and flammable gases in the pump pit. This Acceptance for Beneficial Use documents that Pumping Instrumentation and Control (PIC) skid ''N'' is ready for field use. This document does not cover the field installation or operational testing

  18. Energy Drink Consumption: Beneficial and Adverse Health Effects.

    Science.gov (United States)

    Alsunni, Ahmed Abdulrahman

    2015-10-01

    Consumption of energy drinks has been increasing dramatically in the last two decades, particularly amongst adolescents and young adults. Energy drinks are aggressively marketed with the claim that these products give an energy boost to improve physical and cognitive performance. However, studies supporting these claims are limited. In fact, several adverse health effects have been related to energy drink; this has raised the question of whether these beverages are safe. This review was carried out to identify and discuss the published articles that examined the beneficial and adverse health effects related to energy drink. It is concluded that although energy drink may have beneficial effects on physical performance, these products also have possible detrimental health consequences. Marketing of energy drinks should be limited or forbidden until independent research confirms their safety, particularly among adolescents.

  19. Role and functions of beneficial microorganisms in sustainable aquaculture.

    Science.gov (United States)

    Zhou, Qunlan; Li, Kangmin; Jun, Xie; Bo, Liu

    2009-08-01

    This paper aims to review the development of scientific concepts of microecology and ecology of microbes and the role and functions of beneficial microorganisms in aquaculture and mariculture. Beneficial microorganisms play a great role in natural and man-made aquatic ecosystems based on the co-evolution theory in living biosphere on earth. Their functions are to adjust algal population in water bodies so as to avoid unwanted algal bloom; to speed up decomposition of organic matter and to reduce CODmn, NH3-N and NO2-N in water and sediments so as to improve water quality; to suppress fish/shrimp diseases and water-borne pathogens; to enhance immune system of cultured aquatic animals and to produce bioactive compounds such as vitamins, hormones and enzymes that stimulate growth, thus to decrease the FCR of feed.

  20. FTIR spectroscopic studies of selenite reduction by cells of the rhizobacterium Azospirillum brasilense Sp7 and the formation of selenium nanoparticles

    Science.gov (United States)

    Kamnev, Alexander A.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Tugarova, Anna V.

    2017-07-01

    Microbially driven reduction of selenium oxyanions to elementary selenium, often in the form of nanoparticles (NPs), is widespread in nature. A diversity of possible applications of such biogenic NPs, including those in nanobiotechnology, as well as the specificity of methodologies and mechanisms of their formation via ;green synthesis; are very attractive features justifying further studies of the processes of selenium oxyanion bioreduction and the resulting Se0 nanostructures. In this study, live biomass of the rhizobacterium Azospirillum brasilense Sp7 (harvested after the logarithmic growth phase and washed from culture medium components) was used to obtain extracellular Se NPs relatively homogeneous in size (with average diameters within 50-100 nm) in the process of selenite reduction. Both the control cultures of A. brasilense Sp7 and those incubated with SeO32- (producing Se NPs), as well as the resulting separated Se NPs were studied using Fourier transform infrared (FTIR) spectroscopy in the transmission mode (measured as dried layers on a ZnSe disc), in addition to transmission electron microscopy (TEM), to compare metabolic changes in cells and the bioorganic layers associated with the Se NPs. In the control culture (stored for 24 h in physiological saline), FTIR spectroscopic signs of poly-3-hydroxybutyrate (a 'reserve' biopolyester) were observed as a response to the lack of nutrients (trophic stress), whereas they were virtually absent in cells incubated for 24 h in physiological saline with 10 mM SeO32- (toxicity stress). FTIR spectra of Se NPs separated from bacterial cells showed bands typical of proteins, polysaccharides and lipids associated with the particles (in line with their TEM images showing a thin layer over the NPs), in addition to strong carboxylate bands, which evidently stabilise the NP structure and morphology.

  1. Adubação nitrogenada associada à inoculação com Azospirillum brasilense e Herbaspirillum seropedicae na cultura do milho

    Directory of Open Access Journals (Sweden)

    Janaína Dartora

    2013-10-01

    Full Text Available Bactérias dos gêneros Azospirillum e Herbaspirillum são fixadoras de nitrogênio (N atmosférico e consideradas promotoras do crescimento vegetal. Desta forma, desenvolveu-se o presente trabalho com o objetivo de avaliar o desenvolvimento e a produtividade do milho em resposta à inoculação de A. brasilense e H. seropedicae associada à adubação nitrogenada. O experimento foi conduzido em delineamento experimental de blocos ao acaso em esquema fatorial 4 x 5, com quatro repetições. Os tratamentos foram constituídos da inoculação de sementes (testemunha, estirpe de A. brasilense - Ab-V5, estirpe de H. seropedicae - SmR1 e combinação Ab-V5 + SmR1 e doses de N (0, 40, 80, 120 e 160 kg ha-1 de N. Foram avaliados: diâmetro basal do colmo, altura de planta, matéria seca de parte aérea e área foliar, nas fases vegetativa e reprodutiva, e produtividade. A adubação nitrogenada favoreceu o desenvolvimento da cultura até a máxima dose estudada. A inoculação combinada das estirpes proporcionou incrementos de 12% na matéria seca de parte aérea e 7% na produtividade em relação à testemunha indicando benefícios da combinação de bactérias diazotróficas que interagem de forma diferenciada com a planta.

  2. Chromosomal flhB1 gene of the alphaproteobacterium Azospirillum brasilense Sp245 is essential for correct assembly of both constitutive polar flagellum and inducible lateral flagella.

    Science.gov (United States)

    Filip'echeva, Yulia; Shelud'ko, Andrei; Prilipov, Alexei; Telesheva, Elizaveta; Mokeev, Dmitry; Burov, Andrei; Petrova, Lilia; Katsy, Elena

    2018-03-01

    Azospirillum brasilense has the ability of swimming and swarming motility owing to the work of a constitutive polar flagellum and inducible lateral flagella, respectively. The interplay between these flagellar systems is poorly understood. One of the key elements of the flagellar export apparatus is the protein FlhB. Two predicted flhB genes are present in the genome of A. brasilense Sp245 (accession nos. HE577327-HE577333). Experimental evidence obtained here indicates that the chromosomal coding sequence (CDS) AZOBR_150177 (flhB1) of Sp245 is essential for the production of both types of flagella. In an flhB1:: Omegon-Km mutant, Sp245.1063, defects in polar and lateral flagellar assembly and motility were complemented by expressing the wild-type flhB1 gene from plasmid pRK415. It was found that Sp245.1063 lost the capacity for slight but statistically significant decrease in mean cell length in response to transfer from solid to liquid media, and vice versa; in the complemented mutant, this capacity was restored. It was also shown that after the acquisition of the pRK415-harbored downstream CDS AZOBR_150176, cells of Sp245 and Sp245.1063 ceased to elongate on solid media. These initial data suggest that the AZOBR_150176-encoded putative multisensory hybrid sensor histidine kinase-response regulator, in concert with FlhB1, plays a role in morphological response of azospirilla to changes in the hardness of a milieu.

  3. Evidence for ferritin as dominant iron-bearing species in the rhizobacterium Azospirillum brasilense Sp7 provided by low-temperature/in-field Mössbauer spectroscopy.

    Science.gov (United States)

    Kovács, Krisztina; Kamnev, Alexander A; Pechoušek, Jiří; Tugarova, Anna V; Kuzmann, Ernő; Machala, Libor; Zbořil, Radek; Homonnay, Zoltán; Lázár, Károly

    2016-02-01

    For the ubiquitous diazotrophic rhizobacterium Azospirillum brasilense, which has been attracting the attention of researchers worldwide for the last 35 years owing to its significant agrobiotechnological and phytostimulating potential, the data on iron acquisition and its chemical speciation in cells are scarce. In this work, for the first time for azospirilla, low-temperature (at 80 K, 5 K, as well as at 2 K without and with an external magnetic field of 5 T) transmission Mössbauer spectroscopic studies were performed for lyophilised biomass of A. brasilense (wild-type strain Sp7 grown with (57)Fe(III) nitrilotriacetate complex as the sole source of iron) to enable quantitative chemical speciation analysis of the intracellular iron. In the Mössbauer spectrum at 80 K, a broadened quadrupole doublet of high-spin iron(III) was observed with a few percent of a high-spin iron(II) contribution. In the spectrum measured at 5 K, a dominant magnetically split component appeared with the parameters typical of ferritin species from other bacteria, together with a quadrupole doublet of a superparamagnetic iron(III) component and a similarly small contribution from the high-spin iron(II) component. The Mössbauer spectra recorded at 2 K (with or without a 5 T external field) confirmed the assignment of ferritin species. About 20% of total Fe in the dry cells of A. brasilense strain Sp7 were present in iron(III) forms superparamagnetic at both 5 and 2 K, i.e. either different from ferritin cores or as ferritin components with very small particle sizes.

  4. Dual RNA-seq transcriptional analysis of wheat roots colonized by Azospirillum brasilense reveals up-regulation of nutrient acquisition and cell cycle genes.

    Science.gov (United States)

    Camilios-Neto, Doumit; Bonato, Paloma; Wassem, Roseli; Tadra-Sfeir, Michelle Z; Brusamarello-Santos, Liziane C C; Valdameri, Glaucio; Donatti, Lucélia; Faoro, Helisson; Weiss, Vinicius A; Chubatsu, Leda S; Pedrosa, Fábio O; Souza, Emanuel M

    2014-05-16

    The rapid growth of the world's population demands an increase in food production that no longer can be reached by increasing amounts of nitrogenous fertilizers. Plant growth promoting bacteria (PGPB) might be an alternative to increase nitrogenous use efficiency (NUE) in important crops such wheat. Azospirillum brasilense is one of the most promising PGPB and wheat roots colonized by A. brasilense is a good model to investigate the molecular basis of plant-PGPB interaction including improvement in plant-NUE promoted by PGPB. We performed a dual RNA-Seq transcriptional profiling of wheat roots colonized by A. brasilense strain FP2. cDNA libraries from biological replicates of colonized and non-inoculated wheat roots were sequenced and mapped to wheat and A. brasilense reference sequences. The unmapped reads were assembled de novo. Overall, we identified 23,215 wheat expressed ESTs and 702 A. brasilense expressed transcripts. Bacterial colonization caused changes in the expression of 776 wheat ESTs belonging to various functional categories, ranging from transport activity to biological regulation as well as defense mechanism, production of phytohormones and phytochemicals. In addition, genes encoding proteins related to bacterial chemotaxi, biofilm formation and nitrogen fixation were highly expressed in the sub-set of A. brasilense expressed genes. PGPB colonization enhanced the expression of plant genes related to nutrient up-take, nitrogen assimilation, DNA replication and regulation of cell division, which is consistent with a higher proportion of colonized root cells in the S-phase. Our data support the use of PGPB as an alternative to improve nutrient acquisition in important crops such as wheat, enhancing plant productivity and sustainability.

  5. PRODUTIVIDADE DO TRIGO IRRIGADO SUBMETIDO À APLICAÇÃO DE NITROGÊNIO E À INOCULAÇÃO COM AZOSPIRILLUM BRASILENSE

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Marques Paula Nunes

    2015-02-01

    Full Text Available Inocular sementes de trigo com Azospirillum brasilense pode ser benéfico à cultura do trigo, bem como reduzir a necessidade de aplicação de N. No entanto, são escassos trabalhos que mensurem o benefício dessa prática no trigo irrigado com expectativa de alta produtividade e demanda de N. Objetivou-se com este trabalho avaliar a produtividade e o conteúdo de N na planta do trigo irrigado, submetido a doses de N, com ou sem a inoculação com A. brasilense. Foram conduzidos dois experimentos em 2011 e repetidos em 2012. Em cada ano de cultivo, instalou-se um experimento na área considerada de baixa disponibilidade de N no solo (cultivo em sucessão ao milho e outro na com alta disponibilidade (cultivo em sucessão à soja ou cenoura. Os tratamentos consistiram de cinco doses de N e da inoculação ou não com A. brasilense. As doses de N testadas foram 20, 60, 100, 140 e 180 kg ha-1 na área com baixa disponibilidade de N e 20, 50, 80, 110 e 140 kg ha-1 na com alta disponibilidade. O teor de N na folha índice foi aumentado pela inoculação com A. brasilense. Entretanto, o N absorvido não foi influenciado pela inoculação da bactéria. As doses de N aumentaram a produtividade do trigo e esse aumento foi mais evidente no cultivo na área com baixa disponibilidade de N no solo.

  6. Expression of alkyl hydroperoxide reductase is regulated negatively by OxyR1 and positively by RpoE2 sigma factor in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Singh, Sudhir; Dwivedi, Susheel Kumar; Singh, Vijay Shankar; Tripathi, Anil Kumar

    2016-10-01

    OxyR proteins are LysR-type transcriptional regulators, which play an important role in responding to oxidative stress in bacteria. Azospirillum brasilense Sp7 harbours two copies of OxyR. The inactivation of the oxyR1, the gene organized divergently to ahpC in A. brasilense Sp7, led to an increased tolerance to alkyl hydroperoxides, which was corroborated by an increase in alkyl hydroperoxide reductase (AhpC) activity, enhanced expression of ahpC :lacZ fusion and increased synthesis of AhpC protein in the oxyR1::km mutant. The upstream region of ahpC promoter harboured a putative OxyR binding site, T-N11-A. Mutation of T, A or both in the T-N11-Amotif caused derepression of ahpC in A. brasilense suggesting that T-N11-A might be the binding site for a negative regulator. Retardation of the electrophoretic mobility of the T-N11-A motif harbouring oxyR1-ahpC intergenic DNA by recombinant OxyR1, under reducing as well as oxidizing conditions, indicated that OxyR1 acts as a negative regulator of ahpC in A. brasilense. Sequence of the promoter of ahpC, predicted on the basis of transcriptional start site, and an enhanced expression of ahpC:lacZ fusion in chrR2::km mutant background suggested that ahpC promoter was RpoE2 dependent. Thus, this study shows that in A. brasilense Sp7, ahpC expression is regulated negatively by OxyR1 but is regulated positively by RpoE2, an oxidative-stress-responsive sigma factor. It also shows that OxyR1 regulates the expression RpoE1, which is known to play an important role during photooxidative stress in A. brasilense.

  7. A constitutively expressed pair of rpoE2-chrR2 in Azospirillum brasilense Sp7 is required for survival under antibiotic and oxidative stress.

    Science.gov (United States)

    Gupta, Namrata; Kumar, Santosh; Mishra, Mukti Nath; Tripathi, Anil Kumar

    2013-02-01

    Extracytoplasmic function (ECF) sigma factors (σ(E)) are known to bring about changes in gene expression to enable bacteria to adapt to different stresses. The Azospirillum brasilense Sp245 genome harbours nine genes encoding σ(E), of which two are adjacent to the genes encoding ChrR-type zinc-binding anti-sigma (ZAS) factors. We describe here the role and regulation of a new pair of rpoE-chrR, which was found in the genome of A. brasilense Sp7 in addition to the previously described rpoE-chrR pair (designated rpoE1-chrR1). The rpoE2-chrR2 pair is also cotranscribed, and their products show protein-protein interaction. The -10 and -35 promoter elements of rpoE2-chrR2 and rpoE1-chrR1 were similar but not identical. Unlike the promoter of rpoE1-chrR1, the rpoE2-chrR2 promoter was neither autoregulated nor induced by oxidative stress. Inactivation of chrR2 or overexpression of rpoE2 in A. brasilense Sp7 resulted in an overproduction of carotenoids. It also conferred resistance to oxidative stresses and antibiotics. By controlling the synthesis of carotenoids, initiation and elongation of translation, protein folding and purine biosynthesis, RpoE2 seems to play a crucial role in preventing and repairing the cellular damage caused by oxidative stress. Lack of autoregulation and constitutive expression of rpoE2-chrR2 suggest that RpoE2-ChrR2 may provide a rapid mechanism to cope with oxidative stress, wherein singlet oxygen ((1)O(2))-mediated dissociation of the RpoE2-ChrR2 complex might release RpoE2 to drive the expression of its target genes.

  8. Gene encoding gamma-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Kaur, Simarjot; Mishra, Mukti N; Tripathi, Anil K

    2010-07-04

    Carbonic anhydrase (CA) is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (gamma-CAs) are widespread in prokaryotes but their physiological roles remain elusive. At present, only gamma-CA of Methanosarcina thermophila (Cam) has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one beta-CA and two gamma-CAs. One of the putative gamma-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-gamma-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1). Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a gamma-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized gamma-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration.

  9. An extracytoplasmic function sigma factor cotranscribed with its cognate anti-sigma factor confers tolerance to NaCl, ethanol and methylene blue in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Mishra, Mukti Nath; Kumar, Santosh; Gupta, Namrata; Kaur, Simarjot; Gupta, Ankush; Tripathi, Anil K

    2011-04-01

    Azospirillum brasilense, a plant-growth-promoting rhizobacterium, is exposed to changes in its abiotic environment, including fluctuations in temperature, salinity, osmolarity, oxygen concentration and nutrient concentration, in the rhizosphere and in the soil. Since extra-cytoplasmic function (ECF) sigma factors play an important role in stress adaptation, we analysed the role of ECF sigma factor (also known as RpoE or σ(E)) in abiotic stress tolerance in A. brasilense. An in-frame rpoE deletion mutant of A. brasilense Sp7 was carotenoidless and slow-growing, and was sensitive to salt, ethanol and methylene blue stress. Expression of rpoE in the rpoE deletion mutant complemented the defects in growth, carotenoid biosynthesis and sensitivity to different stresses. Based on data from reverse transcriptase-PCR, a two-hybrid assay and a pull-down assay, we present evidence that rpoE is cotranscribed with chrR and the proteins synthesized from these two overlapping genes interact with each other. Identification of the transcription start site by 5' rapid amplification of cDNA ends showed that the rpoE-chrR operon was transcribed by two promoters. The proximal promoter was less active than the distal promoter, whose consensus sequence was characteristic of RpoE-dependent promoters found in alphaproteobacteria. Whereas the proximal promoter was RpoE-independent and constitutively expressed, the distal promoter was RpoE-dependent and strongly induced in response to stationary phase and elevated levels of ethanol, salt, heat and methylene blue. This study shows the involvement of RpoE in controlling carotenoid synthesis as well as in tolerance to some abiotic stresses in A. brasilense, which might be critical in the adaptation, survival and proliferation of this rhizobacterium in the soil and rhizosphere under stressful conditions.

  10. Beneficial and Harmful Agile Practices for Product Quality

    OpenAIRE

    Theobald, Sven; Diebold, Philipp

    2017-01-01

    There is the widespread belief that Agile neglects the product quality. This lack of understanding how Agile processes assure the quality of the product prevents especially companies from regulated domains from an adoption of Agile. This work aims to identify which Agile Practices contribute towards product quality. Hence, data from a survey study is analyzed to identify Ag-ile Practices which are beneficial or harmful for the quality of the product. From 49 practices that were used in the su...

  11. Health effects of predatory beneficial mites and wasps in greenhouses

    DEFF Research Database (Denmark)

    Bælum, Jesper; Enkegaard, Annie; Doekes, Gert

    A three-year study of 579 greenhouse workers in 31 firms investigated the effect of four different beneficial arthropods. It was shown that the thrips mite Amblyseeius cucumeris and the spider mite predator Phytoseiulus persimilis may cause allergy measured by blood tests as well as eye and nose...... symptoms. No effect was seen by the predator wasp Aphidius colemani nor the predator mite Hypoaspis miles and no effect on lung diseases were seen....

  12. The beneficiation of mumbwa phosphate deposit by various ...

    African Journals Online (AJOL)

    The chemical composition of the ore averages 22.7 % P2O5 with the other constituents being 22.8% SiO2, 19.0% CaO, 7.0% Fe2O3, 4.0 % Al2O3 and 0.2% MgO. Beneficiation studies were performed to investigate methods of concentrating the phosphate values. Preliminary investigations involved detailed identification of ...

  13. Impacts of Rotation Schemes on Ground-Dwelling Beneficial Arthropods.

    Science.gov (United States)

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2016-10-01

    Crop rotation alters agroecosystem diversity temporally, and increasing the number of crops in rotation schemes can increase crop yields and reduce reliance on pesticides. We hypothesized that increasing the number of crops in annual rotation schemes would positively affect ground-dwelling beneficial arthropod communities. During 2012 and 2013, pitfall traps were used to measure activity-density and diversity of ground-dwelling communities within three previously established, long-term crop rotation studies located in Wisconsin and Illinois. Rotation schemes sampled included continuous corn, a 2-yr annual rotation of corn and soybean, and a 3-yr annual rotation of corn, soybean, and wheat. Insects captured were identified to family, and non-insect arthropods were identified to class, order, or family, depending upon the taxa. Beneficial arthropods captured included natural enemies, granivores, and detritivores. The beneficial community from continuous corn plots was significantly more diverse compared with the community in the 2-yr rotation, whereas the community in the 3-yr rotation did not differ from either rotation scheme. The activity-density of the total community and any individual taxa did not differ among rotation schemes in either corn or soybean. Crop species within all three rotation schemes were annual crops, and are associated with agricultural practices that make infield habitat subject to anthropogenic disturbances and temporally unstable. Habitat instability and disturbance can limit the effectiveness and retention of beneficial arthropods, including natural enemies, granivores, and detritivores. Increasing non-crop and perennial species within landscapes in conjunction with more diverse rotation schemes may increase the effect of biological control of pests by natural enemies. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Dredged Material Management Categories for Tracking Beneficial Use

    Science.gov (United States)

    2015-06-01

    NDC) compiles the project level information and prepares statistics at the Corps-wide level. The NDC maintains information on type of dredge plant ...project level information and prepares statistics at the Corps-wide level. The NDC maintains information on type of dredge plant , volume of sediments...the volume of sediment used for a beneficial purpose. In addition, regulations associated with both the Marine Protection Research and Sanctuaries

  15. Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

    Science.gov (United States)

    Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

    2011-02-01

    High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

  16. Beneficial reuse of a national resource from the nuclear enterprise

    International Nuclear Information System (INIS)

    Large, D.

    1993-01-01

    The purpose of this paper is to describe a vital national resource existing within and being generated by the US nuclear enterprise and current and planned technologies and techniques for its beneficial use. Several million tons of radioactively contaminated metals, considered scrap and waste, have been identified at the many commercial and federal sites involved in the nuclear enterprise. Both the public and private sectors have several concerns regarding the disposition of existing inventories and potential generation of contaminated scrap metals. In the past, good metal has been buried as waste. The time has come and is long overdue for that practice to cease. In the late eighties, the US Department of Energy's (DOE's) Oak Ridge office pioneered the move to involve private industry in dealing with the contaminated scrap metal under its purview. Consequently, the Scientific Ecology Group, Inc. (SEG) emerged as the leader in processing contaminated metal for beneficial reuse. To use and advance the technologies and techniques for disposal of radioactively contaminated metals, SEG has built and operates in Oak Ridge, Tennessee, a metal processing facility (MPF). This MPF is used to process radioactively contaminated metals, rid them of most of the contamination, and form them into customized shield blocks and other beneficial-use items. Significant volume reduction for scrap metals (estimated to be in excess of 20 to 1) is achieved with metal-melting services

  17. 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

  18. Characterization of the radioresistance in the radioresistant bacterium deinococcus radiodurans

    International Nuclear Information System (INIS)

    Kong Xiangrong; Du Zeji

    1999-01-01

    The radioresistance of wild type Deinococcus radiodurans KD8301 and the factors affecting the radioresistance were investigated. KH3111 which was a DNA repair mutant of KD8301 (Zeji Du, 1998) was used to be compared with KD8301. Deinococcus radiodurans was discovered by Anderson et al (1956) in X-ray sterilized canned meat that was found to have undergone spoilage. this bacterium and other species of this genus share extreme resistance to ionizing radiation and other agents that damage DNA. Wild type KD8301 and its sensitive mutant KH3111 were irradiated with 60 Co γ-ray at the dose range 0.5 ∼ 10 kGy. Dose-survival fraction curves were made and the radio resistances were determined by LD 99 . The relative contents of DNA in cells were measured by Fluorescence Spectrophotometry (Freedman and Bruce, 1971). The results indicated that wild type KD8301 possesses more radioresistant than its mutant KH3111, LD99 were 9.5 kGy and 2.4 kGy respectively. KD8301 grown at exponential phase showed a decreased resistance to radiation, and the LD99 was 5.1 kGy. No differences of DNA/protein in cells were found between the exponential phase and the stationary phase. The results could be concluded that wild type KD8301 possesses remarkable radioresistance, but this ability was decreased or disappeared after mutation (in KH3111). None DNA relative content other than the growth stages were determinant factors of radioresistance in Deinococcus radiodurans. This results were different from other report (Dickie N et al, 1990). The cellular mechanisms might be the deference's of the bacterium cell morphology between the exponential phase and the stationary phase. Recently, the mutation site of KH3111 which was mutated chemically from wild type KD8301 was identified (Zeji Du, 1998). One base pair changed in the novel gene pprA which was isolated from KD8301 genomic DNA. This point mutation was confirmed to be responsible for the sensitivity of KH3111 to γ-ray and other DNA

  19. Electromicrobiology of Dissimilatory Sulfur Reducing Bacterium Desulfuromonas acetexigens

    KAUST Repository

    Bin Bandar, Khaled

    2014-12-01

    Bioelectrochmical systems (BES) are engineered electrochemical devices that harness hidden chemical energy of the wastewater in to the form of electricity or hydrogen. Unique microbial communities enrich in these systems for oxidation of organic matter as well as transfer of resulted electron to anode, known them as “electricigens” communities. Exploring novel electricigenesis microbial communities in the nature and understanding their electromicrobiology is one the important aspect for BES systems scale up. Herein, we report first time the electricigenesis property of an anaerobic, fresh water sediment, sulfur reducing bacterium Desulfuromona acetexigens. The electrochemical behavior of D. acetexigens biofilms grown on graphite-rod electrodes in batch-fed mode under an applied potential was investigated with traditional electroanalytical tools, and correlate the electron transfer from biofilms to electrode with a model electricigen Geobacter sulfurreducens electrochemical behavior. Research findings suggest that D. acetexigens has the ability to use electrode as electron acceptor in BES systems through establishing the direct contact with anode by expressing the membrane bound redox proteins, but not due to the secretion of soluble redox mediators. Preliminary results revealed that D. acetexigens express three distinct redox proteins in their membranes for turnover of the electrons from biofilm to electrode, and the 4 whole electricigenesis process observed to be unique in the D. acetexigens compared to that of well-studied model organism G. sulfurreducens.

  20. Yersinia ruckeri sp. nov., the redmouth (RM) bacterium

    Science.gov (United States)

    Ewing, W.H.; Ross, A.J.; Brenner, Don J.; Fanning, G. R.

    1978-01-01

    Cultures of the redmouth (RM) bacterium, one of the etiological agents of redmouth disease in rainbow trout (Salmo gairdneri) and certain other fishes, were characterized by means of their biochemical reactions, by deoxyribonucleic acid (DNA) hybridization, and by determination of guanine-plus-cytosine (G+C) ratios in DNA. The DNA relatedness studies confirmed the fact that the RM bacteria are members of the family Enterobacteriaceae and that they comprise a single species that is not closely related to any other species of Enterobacteriaceae. They are about 30% related to species of both Serratia and Yersinia. A comparison of the biochemical reactions of RM bacteria and serratiae indicated that there are many differences between these organisms and that biochemically the RM bacteria are most closely related to yersiniae. The G+C ratios of RM bacteria were approximated to be between 47.5 and 48.5% These values are similar to those of yersiniae but markedly different from those of serratiae. On the basis of their biochemical reactions and their G+C ratios, the RM bacteria are considered to be a new species of Yersinia, for which the name Yersinia ruckeri is proposed. Strain 2396-61 (= ATCC 29473) is designated the type strain of the species.

  1. Beneficial Insect Borders Provide Northern Bobwhite Brood Habitat

    Science.gov (United States)

    Moorman, Christopher E.; Plush, Charles J.; Orr, David B.; Reberg-Horton, Chris

    2013-01-01

    Strips of fallow vegetation along cropland borders are an effective strategy for providing brood habitat for declining populations of upland game birds (Order: Galliformes), including northern bobwhite (Colinus virginianus), but fallow borders lack nectar-producing vegetation needed to sustain many beneficial insect populations (e.g., crop pest predators, parasitoids, and pollinator species). Planted borders that contain mixes of prairie flowers and grasses are designed to harbor more diverse arthropod communities, but the relative value of these borders as brood habitat is unknown. We used groups of six human-imprinted northern bobwhite chicks as a bioassay for comparing four different border treatments (planted native grass and prairie flowers, planted prairie flowers only, fallow vegetation, or mowed vegetation) as northern bobwhite brood habitat from June-August 2009 and 2010. All field border treatments were established around nine organic crop fields. Groups of chicks were led through borders for 30-min foraging trials and immediately euthanized, and eaten arthropods in crops and gizzards were measured to calculate a foraging rate for each border treatment. We estimated arthropod prey availability within each border treatment using a modified blower-vac to sample arthropods at the vegetation strata where chicks foraged. Foraging rate did not differ among border treatments in 2009 or 2010. Total arthropod prey densities calculated from blower-vac samples did not differ among border treatments in 2009 or 2010. Our results showed plant communities established to attract beneficial insects should maximize the biodiversity potential of field border establishment by providing habitat for beneficial insects and young upland game birds. PMID:24376759

  2. Trimethylamine and trimethylamine N-oxide are supplementary energy sources for a marine heterotrophic bacterium: implications for marine carbon and nitrogen cycling.

    Science.gov (United States)

    Lidbury, Ian D E A; Murrell, J Colin; Chen, Yin

    2015-03-01

    Bacteria of the marine Roseobacter clade are characterised by their ability to utilise a wide range of organic and inorganic compounds to support growth. Trimethylamine (TMA) and trimethylamine N-oxide (TMAO) are methylated amines (MA) and form part of the dissolved organic nitrogen pool, the second largest source of nitrogen after N2 gas, in the oceans. We investigated if the marine heterotrophic bacterium, Ruegeria pomeroyi DSS-3, could utilise TMA and TMAO as a supplementary energy source and whether this trait had any beneficial effect on growth. In R. pomeroyi, catabolism of TMA and TMAO resulted in the production of intracellular ATP which in turn helped to enhance growth rate and growth yield as well as enhancing cell survival during prolonged energy starvation. Furthermore, the simultaneous use of two different exogenous energy sources led to a greater enhancement of chemoorganoheterotrophic growth. The use of TMA and TMAO primarily as an energy source resulted in the remineralisation of nitrogen in the form of ammonium, which could cross feed into another bacterium. This study provides greater insight into the microbial metabolism of MAs in the marine environment and how it may affect both nutrient flow within marine surface waters and the flux of these climatically important compounds into the atmosphere.

  3. ANALYSIS OF WEB MINING APPLICATIONS AND BENEFICIAL AREAS

    Directory of Open Access Journals (Sweden)

    Khaleel Ahmad

    2011-10-01

    Full Text Available The main purpose of this paper is to study the process of Web mining techniques, features, application ( e-commerce and e-business and its beneficial areas. Web mining has become more popular and its widely used in varies application areas (such as business intelligent system, e-commerce and e-business. The e-commerce or e-business results are bettered by the application of the mining techniques such as data mining and text mining, among all the mining techniques web mining is better.

  4. Status of the Beneficial Uses Shipping System cask (BUSS)

    International Nuclear Information System (INIS)

    Yoshimura, H.R.; Eakes, R.G.; Bronowski, D.R.

    1994-01-01

    The Beneficial Uses Shipping System cask is a Type B packaging developed by Sandia National Laboratories for the U.S. Department of Energy. The cask is designed to transport special form radioactive source capsules (cesium chloride and strontium fluoride) produced by the Department of Energy's Hanford Waste Encapsulation and Storage Facility. This paper describes the cask system and the analyses performed to predict the response of the cask in impact, puncture, and fire accident conditions as specified in the regulations. The cask prototype has been fabricated and Certificates of Compliance have been obtained

  5. [Coffee can be beneficial for patients with liver diseases].

    Science.gov (United States)

    Kjærgaard, Maria; Thiele, Maja; Krag, Aleksander

    2014-10-20

    Coffee is one of the most commonly consumed beverages in the world. Consequently, it is important to consider the impact of coffee on health and disease. A daily intake of at least three cups of coffee is likely to have beneficial health effects, especially in patients at risk of liver diseases. Coffee has been associated with decreased liver inflammation, prevention of cirrhosis, reduced steatosis and lower incidence of hepatocellular carcinoma. It is not yet possible to make clear recommendations, but coffee can likely be included as part of a healthy diet for patients with liver diseases.

  6. Ethics as a beneficial Trojan horse in a technological society.

    Science.gov (United States)

    Queraltó, Ramón

    2013-03-01

    This article explores the transformation of ethics in a globalizing technological society. After describing some basic features of this society, particularly the primacy it gives to a special type of technical rationality, three specific influences on traditional ethics are examined: (1) a change concerning the notion of value, (2) the decreasing relevance of the concept of axiological hierarchy, and (3) the new internal architecture of ethics as a net of values. These three characteristics suggest a new pragmatic understanding of ethics. From a pragmatic perspective, the process of introducing ethical values into contemporary society can be regarded as a beneficial Trojan horse, a metaphor that will be developed further.

  7. Interactions between Pteris vittata L. genotypes and a polycyclic aromatic hydrocarbon (PAH)-degrading bacterium (Alcaligenes sp.) in arsenic uptake and PAH-dissipation.

    Science.gov (United States)

    Sun, Lu; Zhu, Ganghui; Liao, Xiaoyong; Yan, Xiulan

    2017-11-01

    The effects of two Pteris vittata L. accessions and a polycyclic aromatic hydrocarbon (PAH)-degrading bacterium (Alcaligenes sp.) on arsenic (As) uptake and phenanthrene dissipation were studied. The Alcaligenes sp. survived in the rhizosphere and improved soil As bioavailability with co-exposure. However, bacterial inoculation altered Pteris vittata L. stress tolerance, and substantially affected the As distribution in the rhizosphere of the two P. vittata accessions. Bacterial inoculation was beneficial to protect the Guangxi accession against the toxic effects, and significantly increased plant As and phenanthrene removal ratios by 27.8% and 2.89%, respectively. In contrast, As removal was reduced by 29.8% in the Hunan accession, when compared with corresponding non-inoculated treatments. We conclude that plant genotype selection is critically important for successful microorganism-assisted phytoremediation of soil co-contaminated with As and PAHs, and appropriate genotype selection may enhance remediation efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Characterization of a Neochlamydia-like Bacterium Associated with Epitheliocystis in Cultured Artic Char Salvelinus alpinus

    Science.gov (United States)

    Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic char (Salvelinus alpinus). To characterize a bacterium associated with epitheliocystis in cultured char, gills were sampled for histopathologic examination, conventional...

  9. Echinicola shivajiensis sp. nov., a novel bacterium of the family "Cyclobacteriaceae" isolated from brackish water pond

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; Tryambak, B.K.; AnilKumar, P.

    Strain AK12 sup(T), an orange pigmented Gramnegative, rod shaped, non-motile bacterium, was isolated fromamud sample collected froma brackishwater pond at Rampur of West Bengal, India. The strain was positive for oxidase, catalase and phosphatase...

  10. Reclassification of Clostridium proteoclasticum as Butyrivibrio proteoclasticus comb. nov., a butyrate-producing ruminal bacterium

    Czech Academy of Sciences Publication Activity Database

    Moon, C. D.; Pacheco, D. M.; Kelly, W. J.; Leahy, S. C.; Li, D.; Kopečný, Jan; Attwood, G. T.

    2008-01-01

    Roč. 58, - (2008), s. 2041-2045 ISSN 1466-5026 Institutional research plan: CEZ:AV0Z50450515 Keywords : Butyrivibrio * ruminal bacterium Subject RIV: EE - Microbiology, Virology Impact factor: 2.222, year: 2008

  11. Septicemia caused by the gram-negative bacterium CDC IV c-2 in an immunocompromised human.

    OpenAIRE

    Dan, M; Berger, S A; Aderka, D; Levo, Y

    1986-01-01

    A 37-year-old man with plasma cell leukemia developed nonfatal septicemia caused by the gram-negative bacterium CDC IV c-2. Recovery followed appropriate treatment with antibiotics. The biochemical features of this organism are reviewed.

  12. Carbohydrate utilization patterns for the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus reveal broad growth substrate preferences

    NARCIS (Netherlands)

    Vanfossen, A.L.; Verhaart, M.R.A.; Kengen, S.W.M.; Kelly, R.M.

    2009-01-01

    Co-utilization of hexoses and pentoses derived from lignocellulose is an attractive trait in microorganisms considered for consolidated biomass processing to biofuels. This issue was examined for the H2-producing, extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus growing on

  13. 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.

  14. Non-alcoholic Fatty Liver Disease: Beneficial Effects of Flavonoids.

    Science.gov (United States)

    Akhlaghi, Masoumeh

    2016-10-01

    Non-alcoholic fatty liver disease (NAFLD) has been known as the hepatic feature of metabolic syndrome. Extra fat depots, especially in visceral areas, develop insulin resistance as a result of mild oxidation and inflammation. Insulin resistance induces lipolysis and releases free fatty acids into the circulation, where they are transported to the liver. In the liver, free fatty acids are converted to triglycerides and accumulate, causing simple steatosis that, if left untreated, can lead to steatohepatitis, and subsequently liver necrosis and cirrhosis.Flavonoids, a group of plant compounds with incredible biological characteristics, have shown advantages in pathological conditions. Beneficial effects of flavonoids against NAFLD and its related disorders have been observed in both animal and human studies. Various mechanisms have been found for their protection. Flavonoids prevent hepatosteatosis by increasing fatty acid oxidation in the liver. They can also reduce caloric intake and decrease body weight and fat deposition in visceral tissues. Flavonoids are unique antioxidants that exert their beneficial effects through inhibition of nuclear factor κB, thereby attenuating release of inflammatory cytokines, which are triggers of insulin resistance. Finally, flavonoids have shown to increase adiponectin, improve insulin sensitivity and glucose tolerance, correct dyslipidemia, and reduce blood pressure in patients with NAFLD. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Beneficial uses program. Progress report, period ending June 30, 1977

    International Nuclear Information System (INIS)

    1977-12-01

    The Beneficial Uses Program is a comprehensive program aimed at developing necessary technologies for cost/beneficial uses of existing and future surplus radioactive materials. The major portion of the work at Sandia has been concentrated in two subprograms: the Waste Resources Utilization Program and the Separation Technology and Source Development Program. Mutagenicity testing of sludge by the Ames method was initiated this quarter. Rats were procured and maintained on phenobarbital to enduce liver enzymes used in the preparation of the S-9 fraction for the Ames tests. Initial tests in the absence of S-9 metabolic activation did not show raw and digested sludges to be mutagenic. Settling studies using centrifugation techniques have confirmed that radiation treatment causes a significant increase in prompt settlability, while at longer times, the improvement is insignificant compared to the effectiveness of polymer-conditioning agents. The use of gamma irradiation to improve the settlability of sewage sludge will have limited application. The conveyor system for the dried sludge irradiation pilot plant was received from Gough Econ, Staffordshire, England. Both esophageal-fistulated and intact steers were fitted with fecal collection bags and used in grazing experiments. Supplementation with dried irradiated primary sewage solids improved not only the protein status of the steers, but also exerted measurable and important effects on the composition of forage selectively grazed

  16. Identifying Beneficial Qualities of Trichoderma parareesei for Plants

    Science.gov (United States)

    Rubio, M. Belén; Quijada, Narciso M.; Pérez, Esclaudys; Domínguez, Sara; Hermosa, Rosa

    2014-01-01

    Trichoderma parareesei and Trichoderma reesei (teleomorph Hypocrea jecorina) produce cellulases and xylanases of industrial interest. Here, the anamorphic strain T6 (formerly T. reesei) has been identified as T. parareesei, showing biocontrol potential against fungal and oomycete phytopathogens and enhanced hyphal growth in the presence of tomato exudates or plant cell wall polymers in in vitro assays. A Trichoderma microarray was used to examine the transcriptomic changes in T6 at 20 h of interaction with tomato plants. Out of a total 34,138 Trichoderma probe sets deposited on the microarray, 250 showed a significant change of at least 2-fold in expression in the presence of tomato plants, with most of them being downregulated. T. parareesei T6 exerted beneficial effects on tomato plants in terms of seedling lateral root development, and in adult plants it improved defense against Botrytis cinerea and growth promotion under salt stress. Time course expression patterns (0 to 6 days) observed for defense-related genes suggest that T6 was able to prime defense responses in the tomato plants against biotic and abiotic stresses. Such responses undulated, with a maximum upregulation of the jasmonic acid (JA)/ethylene (ET)-related LOX1 and EIN2 genes and the salt tolerance SOS1 gene at 24 h and that of the salicylic acid (SA)-related PR-1 gene at 48 h after T6 inoculation. Our study demonstrates that the T. parareesei T6-tomato interaction is beneficial to both partners. PMID:24413597

  17. Perlecan and the Blood-Brain Barrier: Beneficial Proteolysis?

    Directory of Open Access Journals (Sweden)

    Jill eRoberts

    2012-08-01

    Full Text Available The cerebral microvasculature is important for maintaining brain homeostasis. This is achieved via the blood-brain barrier (BBB, composed of endothelial cells with specialized tight junctions, astrocytes and a basement membrane. Prominent components of the basement membrane extracellular matrix (ECM include fibronectin, laminin, collagen IV and perlecan, all of which regulate cellular processes via signal transduction through various cell membrane bound ECM receptors. Expression and proteolysis of these ECM components can be rapidly altered during pathological states of the central nervous system. In particular, proteolysis of perlecan, a heparan sulfate proteoglycan, occurs within hours following ischemia induced by experimental stroke. Proteolysis of ECM components following stroke results in the degradation of the basement membrane and further disruption of the BBB. While it is clear that such proteolysis has negative consequences for the BBB, we propose that it also may lead to generation of ECM protein fragments, including the C-terminal domain V (DV of perlecan, that potentially have a positive influence on other aspects of CNS health. Indeed, perlecan DV has been shown to be persistently generated after stroke and beneficial as a neuroprotective molecule and promoter of post-stroke brain repair. This mini-review will discuss beneficial roles of perlecan protein fragment generation within the brain during stroke.

  18. Characterization and Beneficiation Studies of a Low Grade Bauxite Ore

    Science.gov (United States)

    Rao, D. S.; Das, B.

    2014-10-01

    A low grade bauxite sample of central India was thoroughly characterized with the help of stereomicroscope, reflected light microscope and electron microscope using QEMSCAN. A few hand picked samples were collected from different places of the mine and were subjected to geochemical characterization studies. The geochemical studies indicated that most of the samples contain high silica and low alumina, except a few which are high grade. Mineralogically the samples consist of bauxite (gibbsite and boehmite), ferruginous mineral phases (goethite and hematite), clay and silicate (quartz), and titanium bearing minerals like rutile and ilmenite. Majority of the gibbsite, boehmite and gibbsitic oolites contain clay, quartz and iron and titanium mineral phases within the sample as inclusions. The sample on an average contains 39.1 % Al2O3 and 12.3 % SiO2, and 20.08 % of Fe2O3. Beneficiation techniques like size classification, sorting, scrubbing, hydrocyclone and magnetic separation were employed to reduce the silica content suitable for Bayer process. The studies indicated that, 50 % by weight with 41 % Al2O3 containing less than 5 % SiO2 could be achieved. The finer sized sample after physical beneficiation still contains high silica due to complex mineralogical associations.

  19. Complete genome of Martelella sp. AD-3, a moderately halophilic polycyclic aromatic hydrocarbons-degrading bacterium.

    Science.gov (United States)

    Cui, Changzheng; Li, Zhijie; Qian, Jiangchao; Shi, Jie; Huang, Ling; Tang, Hongzhi; Chen, Xin; Lin, Kuangfei; Xu, Ping; Liu, Yongdi

    2016-05-10

    Martelella sp. strain AD-3, a moderate halophilic bacterium, was isolated from a petroleum-contaminated soil with high salinity in China. Here, we report the complete genome of strain AD-3, which contains one circular chromosome and two circular plasmids. An array of genes related to metabolism of polycyclic aromatic hydrocarbons and halophilic mechanism in this bacterium was identified by the whole genome analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Endohyphal bacterium enhances production of indole-3-acetic acid by a foliar fungal endophyte.

    Directory of Open Access Journals (Sweden)

    Michele T Hoffman

    Full Text Available Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA, often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales, but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales. Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions.

  1. Coberturas vegetais, doses de nitrogênio e inoculação de sementes com Azospirillum brasilense em arroz de terras altas no sistema plantio direto

    Directory of Open Access Journals (Sweden)

    Douglas de Castilho Gitti

    2012-01-01

    Full Text Available O arroz é importante fonte de energia e proteínas para a população mundial, principalmente na Ásia e Oceania. No Brasil, juntamente com o feijão, constitui a base da alimentação. Tecnologias sustentáveis que reduzam custos da produção e aumentem a produtividade do arroz podem garantir seu suprimento em períodos de alta demanda. O objetivo deste trabalho foi avaliar diferentes coberturas vegetais antecessoras (milheto [Pennisetum americanum], crotalária [Crotalaria juncea], guandu [Cajanus cajan], braquiária [Brachiaria ruziziensis], milheto + crotalária e milheto + guandu, doses de nitrogênio (N em cobertura (0, 40, 80 e 120 kg ha-1 e o efeito da inoculação de sementes com Azospirillum brasilense no arroz de terras altas em sistema plantio direto no desenvolvimento e na produtividade. Utilizou-se o delineamento experimental em blocos casualizados em esquema fatorial 6x4x2 com quatro repetições. O estudo foi desenvolvido em um Latossolo Vermelho, em Selvíria, Estado do Mato Grosso do Sul, Brasil, em 2011/2012. O cultivo do guandu antecedendo o arroz proporcionou maior produtividade do arroz somente em comparação a B. ruziziensi. A produtividade do arroz em função das doses de N em cobertura se ajustou a uma função quadrática. Não houve influência da inoculação de sementes com A. brasilense sobre a produtividade do arroz, porém houve interação entre a inoculação e as coberturas vegetais sobre o teor de N foliar, número de panículas por m², matéria seca de plantas de arroz e a massa de cem grãos.

  2. Efecto de la temperatura y el pH en la producción de biomasa de Azospirillum brasilense C16 aislada de pasto guinea

    Directory of Open Access Journals (Sweden)

    F Romero-Perdomo

    Full Text Available El objetivo del estudio fue evaluar el efecto de la temperatura y el pH en la viabilidad celular de la cepa Azospirillum brasilense C16. Se estudiaron cinco temperaturas (entre 28 y 36°C y cinco pH (de 4,5 a 8,5. El efecto de la temperatura se evaluó mediante la medición del crecimiento radial (mm de la cepa, sobre un papel de filtro en medio batata. En el caso del pH se utilizó un fermentador de tanque agitado -con una configuración tipo Rushton- para cuantificar la velocidad de crecimiento, la producción de biomasa y el tiempo de duplicación de la cepa; las condiciones de fermentación fueron: 400 rpm, 1 Lpm y 30°C, durante 24 horas. El pH y la temperatura influyeron significativamente (p < 0,05 en la producción de A. brasilense C16. La temperatura de 30°C fue la más favorable para que se multiplicara la cepa, con 23,21 mm de crecimiento radial; mientras que la mayor o igual a 34°C inhibió su crecimiento. Los mejores resultados se obtuvieron con un pH de 6,8, con diferencias significativas (p < 0,05 respecto al resto. Con esta condición se obtuvieron los valores más altos de velocidad de crecimiento (1,79 h-1 y producción de biomasa (8,65 log10 UFC mL-1, y el valor más bajo del tiempo de duplicación (1,09 h-1. Estos resultados poseen aplicabilidad biotecnológica, y son de gran importancia en el momento de definir y controlar las condiciones de producción masiva de biomasa de A. brasilense C16 para futuras formulaciones como biofertilizante en diversos cultivos de interés en Colombia.

  3. Chemical composition and deoxynivalenol in wheat of Central- Southern Paraná: nitrogen fertilization in top dressing associated with Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    Thiago Montagner Souza

    2014-02-01

    Full Text Available The impact of agricultural management practices on the quality of grain was evaluated in wheat (Triticum aestivum L. BRS Tangará from the South Central region of Paraná State (Ponta Grossa in the crop years of 2010 and 2011. The field trial was carried out in succession with soybean (2010 and corn (2011. The treatments included inoculation of seeds with Azospirillum brasilense and increasing levels of nitrogen application in top dressing (0, 30, 60, 90 and 120 kg ha-1. The experimental design was in randomized block, factorial 2 x 5 (inoculation x N levels, with four replications. The parameters evaluated were water activity, moisture, protein, and grain contamination by deoxynivalenol (DON. The data were subjected to analysis of variance, comparison of means by Tukey’s test (p<0.05 and regression for nitrogen levels. The inoculation of seeds with A. brasilense increased the protein content in grain in 2010 (+1.6%; 16.9 g 100g-1 and 2011 (+1.7%, 15.7 g 100g-1, independently of the nitrogen level (p<0.01. Levels of nitrogen in 2010 presented a positive linear response with protein content, increasing by 14.2% using non-inoculated seeds (p<0.01, R2=0.955 and 14.4% for those inoculated with A. brasilense (p<0.01, R2=0.906. However, in 2011 a quadratic response was observed between nitrogen levels and protein content (p<0.01, R2=0.99, with stabilization or reduction in protein content using high levels of nitrogen (?120 kg ha-1. The contamination by DON was greater using high levels of nitrogen (3574 ?g kg-1, 120 kg ha-1; non-inoculated seeds in 2011, with a quadratic response between nitrogen levels and contamination of grains (p<0.05, R2=0.772. Furthermore, 37.5% of the samples presented contamination by DON higher than the maximum tolerated limit established by Brazilian legislation (2000 ?g kg-1; whole-wheat grain. The data demonstrates that proper management of nitrogen enhances intrinsic effects arising from plant breeding.

  4. Regulation of a Glycerol-Induced Quinoprotein Alcohol Dehydrogenase by σ54 and a LuxR-Type Regulator in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Singh, Vijay Shankar; Dubey, Ashutosh Prakash; Gupta, Ankush; Singh, Sudhir; Singh, Bhupendra Narain; Tripathi, Anil Kumar

    2017-07-01

    Azospirillum brasilense Sp7 uses glycerol as a carbon source for growth and nitrogen fixation. When grown in medium containing glycerol as a source of carbon, it upregulates the expression of a protein which was identified as quinoprotein alcohol dehydrogenase (ExaA). Inactivation of exaA adversely affects the growth of A. brasilense on glycerol. A determination of the transcription start site of exaA revealed an RpoN-dependent -12/-24 promoter consensus. The expression of an exaA :: lacZ fusion was induced maximally by glycerol and was dependent on σ 54 Bioinformatic analysis of the sequence flanking the -12/-24 promoter revealed a 17-bp sequence motif with a dyad symmetry of 6 nucleotides upstream of the promoter, the disruption of which caused a drastic reduction in promoter activity. The electrophoretic mobility of a DNA fragment containing the 17-bp sequence motif was retarded by purified EraR, a LuxR-type transcription regulator that is transcribed divergently from exaA EraR also showed a positive interaction with RpoN in two-hybrid and pulldown assays. IMPORTANCE Quinoprotein alcohol dehydrogenase (ExaA) plays an important role in the catabolism of alcohols in bacteria. Although exaA expression is thought to be regulated by a two-component system consisting of EraS and EraR, the mechanism of regulation was not known. This study shows the details of the regulation of expression of the exaA gene in A. brasilense We have shown here that exaA of A. brasilense is maximally induced by glycerol and harbors a σ 54 -dependent promoter. The response regulator EraR binds to an inverted repeat located upstream of the exaA promoter. This study shows that a LuxR-type response regulator (EraR) binds upstream of the exaA gene and physically interacts with σ 54 The unique feature of this regulation is that EraR is a LuxR-type transcription regulator that lacks the GAFTGA motif, a characteristic feature of the enhancer binding proteins that are known to interact with σ 54

  5. Gene encoding γ-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7

    Science.gov (United States)

    2010-01-01

    Background Carbonic anhydrase (CA) is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (γ-CAs) are widespread in prokaryotes but their physiological roles remain elusive. At present, only γ-CA of Methanosarcina thermophila (Cam) has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one β-CA and two γ-CAs. Results One of the putative γ-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-γ-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1). Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. Conclusions This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a γ-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized γ-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration. PMID:20598158

  6. Cross-talk between cognate and noncognate RpoE sigma factors and Zn(2+)-binding anti-sigma factors regulates photooxidative stress response in Azospirillum brasilense.

    Science.gov (United States)

    Gupta, Namrata; Gupta, Ankush; Kumar, Santosh; Mishra, Rajeev; Singh, Chhaya; Tripathi, Anil Kumar

    2014-01-01

    Azospirillum brasilense harbors two redox-sensitive Zinc-binding anti-sigma (ZAS) factors (ChrR1 and ChrR2), which negatively regulate the activity of their cognate extra-cytoplasmic function (ECF) σ factors (RpoE1 and RpoE2) by occluding their binding to the core enzyme. Both pairs of RpoE-ChrR control responses to photooxidative stress. The aim of this study was to investigate whether the two RpoE-ChrR pairs cross-talk while responding to the stress. In silico analysis showed a high sequence similarity between ChrR1 and ChrR2 proteins, but differences in redox sensitivity. Using in silico and in vitro methods of protein-protein interaction, we have shown that both ChrR1 and ChrR2 proteins physically bind to their noncognate RpoE proteins. Restoration of the phenotypes of chrR1::Tn5 and chrR2::Km mutants related to carotenoid biosynthesis and photooxidative stress tolerance by expressing chrR1 or chrR2 provided in vivo evidence for the cross-talk. In addition, up- or down-regulation of several identical proteins by expressing chrR1 or chrR2 in the chrR1::Tn5 mutant provided another in vivo evidence for the cross-talk. Although multiple redox-sensitive ZAS anti-σ factors occur in some Gram-positive bacteria, no cross-talk is reported among them. We report here, for the first time, that the two ZAS anti-σ factors of A. brasilense also interact with their noncognate σ factors and affect gene expression. The two redox-sensitive ZAS anti-σ factors in A. brasilense may interact with their cognate as well as noncognate ECF σ factors to play an important role in redox homeostasis by facilitating recovery from the oxidative stress.

  7. Optogenetic Manipulation of Cyclic Di-GMP (c-di-GMP) Levels Reveals the Role of c-di-GMP in Regulating Aerotaxis Receptor Activity in Azospirillum brasilense.

    Science.gov (United States)

    O'Neal, Lindsey; Ryu, Min-Hyung; Gomelsky, Mark; Alexandre, Gladys

    2017-09-15

    Bacterial chemotaxis receptors provide the sensory inputs that inform the direction of navigation in changing environments. Recently, we described the bacterial second messenger cyclic di-GMP (c-di-GMP) as a novel regulator of a subclass of chemotaxis receptors. In Azospirillum brasilense , c-di-GMP binds to a chemotaxis receptor, Tlp1, and modulates its signaling function during aerotaxis. Here, we further characterize the role of c-di-GMP in aerotaxis using a novel dichromatic optogenetic system engineered for manipulating intracellular c-di-GMP levels in real time. This system comprises a red/near-infrared-light-regulated diguanylate cyclase and a blue-light-regulated c-di-GMP phosphodiesterase. It allows the generation of transient changes in intracellular c-di-GMP concentrations within seconds of irradiation with appropriate light, which is compatible with the time scale of chemotaxis signaling. We provide experimental evidence that binding of c-di-GMP to the Tlp1 receptor activates its signaling function during aerotaxis, which supports the role of transient changes in c-di-GMP levels as a means of adjusting the response of A. brasilense to oxygen gradients. We also show that intracellular c-di-GMP levels in A. brasilense change with carbon metabolism. Our data support a model whereby c-di-GMP functions to imprint chemotaxis receptors with a record of recent metabolic experience, to adjust their contribution to the signaling output, thus allowing the cells to continually fine-tune chemotaxis sensory perception to their metabolic state. IMPORTANCE Motile bacteria use chemotaxis to change swimming direction in response to changes in environmental conditions. Chemotaxis receptors sense environmental signals and relay sensory information to the chemotaxis machinery, which ultimately controls the swimming pattern of cells. In bacteria studied to date, differential methylation has been known as a mechanism to control the activity of chemotaxis receptors and

  8. Gene encoding γ-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7

    Directory of Open Access Journals (Sweden)

    Mishra Mukti N

    2010-07-01

    Full Text Available Abstract Background Carbonic anhydrase (CA is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (γ-CAs are widespread in prokaryotes but their physiological roles remain elusive. At present, only γ-CA of Methanosarcina thermophila (Cam has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one β-CA and two γ-CAs. Results One of the putative γ-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-γ-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1. Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. Conclusions This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a γ-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized γ-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration.

  9. Luciferase inactivation in the luminous marine bacterium Vibrio harveyi.

    Science.gov (United States)

    Reeve, C A; Baldwin, T O

    1981-06-01

    Luciferase was rapidly inactivated in stationary-phase cultures of the wild type of the luminous marine bacterium Vibrio harveyi, but was stable in stationary-phase cultures of mutants of V. harveyi that are nonluminous without exogenous aldehyde, termed the aldehyde-deficient mutants. The inactivation in the wild type was halted by cell lysis and was slowed or stopped by O2 deprivation or by addition of KCN and NaF or of chloramphenicol. If KCN and NaF or chloramphenicol were added to a culture before the onset of luciferase inactivation, then luciferase inactivation did not occur. However, if these inhibitors were added after the onset of luciferase inactivation, then luciferase inactivation continued for about 2 to 3 h before the inactivation process stopped. The onset of luciferase inactivation in early stationary-phase cultures of wild-type cell coincided with a slight drop in the intracellular adenosine 5'-triphosphate (ATP) level from a relatively constant log-phase value of 20 pmol of ATP per microgram of soluble cell protein. Addition of KCN and NaF to a culture shortly after this drop in ATP caused a rapid decrease in the ATP level to about 4 pmol of ATP per microgram whereas chloramphenicol added at this same time caused a transient increase in ATP level to about 25 pmol/microgram. The aldehyde-deficient mutant (M17) showed a relatively constant log-phase ATP level identical with that of the wild-type cells, but rather than decreasing in early stationary phase, the ATP level increased to a value twice that in log-phase cells. We suggest that the inactivation of luciferase is dependent on the synthesis of some factor which is produced during stationary phase and is itself unstable, and whose synthesis is blocked by chloramphenicol or cyanide plus fluoride.

  10. Spices: the savory and beneficial science of pungency.

    Science.gov (United States)

    Nilius, Bernd; Appendino, Giovanni

    2013-01-01

    Spicy food does not only provide an important hedonic input in daily life, but has also been anedoctically associated to beneficial effects on our health. In this context, the discovery of chemesthetic trigeminal receptors and their spicy ligands has provided the mechanistic basis and the pharmacological means to investigate this enticing possibility. This review discusses in molecular terms the connection between the neurophysiology of pungent spices and the "systemic" effects associated to their trigeminality. It commences with a cultural and historical overview on the Western fascination for spices, and, after analysing in detail the mechanisms underlying the trigeminality of food, the main dietary players from the transient receptor potential (TRP) family of cation channels are introduced, also discussing the "alien" distribution of taste receptors outside the oro-pharingeal cavity. The modulation of TRPV1 and TRPA1 by spices is next described, discussing how spicy sensations can be turned into hedonic pungency, and analyzing the mechanistic bases for the health benefits that have been associated to the consumption of spices. These include, in addition to a beneficial modulation of gastro-intestinal and cardio-vascular function, slimming, the optimization of skeletal muscle performance, the reduction of chronic inflammation, and the prevention of metabolic syndrome and diabetes. We conclude by reviewing the role of electrophilic spice constituents on cancer prevention in the light of their action on pro-inflammatory and pro-cancerogenic nuclear factors like NFκB, and on their interaction with the electrophile sensor protein Keap1 and the ensuing Nrf2-mediated transcriptional activity. Spicy compounds have a complex polypharmacology, and just like any other bioactive agent, show a balance of beneficial and bad actions. However, at least for moderate consumption, the balance seems definitely in favour of the positive side, suggesting that a spicy diet, a caveman

  11. Beneficial Effects of Corn Silk on Metabolic Syndrome.

    Science.gov (United States)

    Wang, Bing; Xiao, Tiegang; Ruan, Jun; Liu, Wensheng

    2017-01-01

    Metabolic syndrome (MS) is a very common medical problem worldwide. It includes obesity, hypertension, hyperglycemia, and abnormal levels of triglycerides and high-density lipoprotein cholesterol. It is closely associated with insulin resistance and may lead to diabetes mellitus, liver diseases, or cardiovascular diseases. Corn silk (CS), a traditional Chinese medicine, has been reported to have multiple beneficial effects, including hypotensive, anti-diabetic, and hypolipidemic properties. This suggests that corn silk could be used to treat or prevent metabolic syndrome. In this review, we will discuss the potential role of corn silk in different components of metabolic syndrome. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Beneficial and harmful roles of bacteria from the Clostridium genus.

    Science.gov (United States)

    Samul, Dorota; Worsztynowicz, Paulina; Leja, Katarzyna; Grajek, Włodzimierz

    2013-01-01

    Bacteria of the Clostridium genus are often described only as a biological threat and a foe of mankind. However, many of them have positive properties and thanks to them they may be used in many industry branches (e.g., in solvents and alcohol production, in medicine, and also in esthetic cosmetology). During the last 10 years interest in application of C. botulinum and C. tetani in medicine significantly increased. Currently, the structure and biochemical properties of neurotoxins produced by these bacterial species, as well as possibilities of application of such toxins as botulinum as a therapeutic factor in humans, are being intensely researched. The main aim of this article is to demonstrate that bacteria from Clostridium spp. are not only pathogens and the enemy of humanity but they also have many important beneficial properties which make them usable among many chemical, medical, and cosmetic applications.

  13. Beneficiation studies of Bajaur manganese ore by different processing techniques

    International Nuclear Information System (INIS)

    Riaz, M.; Khan, F.U.; Yamin, A.; Bilquees, R.; Muhammad, N.

    2010-01-01

    The manganese ore of Bajaur Agency of Pakistan was subjected to flotation, heavy medium separation, gravity concentration and magnetic separation techniques for beneficiation. The original composition of the manganese ore was 45.56% Mn , 4% Fe/sub 2/O/sub 3/, 40% SiO/sub 2/. The Mn content was raised to a maximum 48.76 % in the concentrate with the recovery of 67.78 % through flotation technique. Other techniques rendered marginal increase in Mn concentration against the theoretical possibility of substantial enrichment by rejecting the 20 % gangue minerals. The separation of manganese minerals from associated gangue was difficult, due to mineralogical complexity of the ore, extreme fineness of the particle size, texture and minerals intergrowth. High Mn/Fe ratio, phosphorus, and silica contents were within tolerable limits for utilisation of the ore in ferro-manganese production. (author)

  14. Electricity sector restructuring in India: an environmentally beneficial policy?

    International Nuclear Information System (INIS)

    Perkins, Richard

    2005-01-01

    It has been suggested that reforms to the electricity sector in developing countries encouraging the entry of independent power producers (IPPs) are likely to result in environmental improvements similar to those recently made in a number of developed economies. The present paper evaluates this claim by examining the experience of the Indian power sector. It finds that recent investments by IPPs have reduced the pollution-intensity of electricity generation in the country. Yet they have not brought the significant gains seen in countries such as the UK, nor are they likely to in the foreseeable future. This is largely a product of the nature and context of electricity sector reform in India which is less favourable to environmentally beneficial outcomes. Accordingly, the paper concludes by suggesting that the environmental benefits of restructuring are not automatic, but depend on the existence of an enabling structural, institutional and regulatory framework

  15. Beneficial effects of minocycline on cuprizone induced cortical demyelination.

    Science.gov (United States)

    Skripuletz, Thomas; Miller, Elvira; Moharregh-Khiabani, Darius; Blank, Alexander; Pul, Refik; Gudi, Viktoria; Trebst, Corinna; Stangel, Martin

    2010-09-01

    In this study, we investigated the potential of minocycline to influence cuprizone induced demyelination in the grey and white matter. To induce demyelination C57BL/6 mice were fed with cuprizone for up to 6 weeks and were analysed at different timepoints (week 0, 4, 5, 6). Mice treated with minocycline had less demyelination of the cortex and corpus callosum compared with sham treated animals. In the cortex decreased numbers of activated and proliferating microglia were found after 6 weeks of cuprizone feeding, while there were no significant effects for microglial infiltration of the corpus callosum. In addition to the beneficial effects on demyelination, minocycline prevented from motor coordination disturbance as shown in the beam walking test. For astrogliosis and the numbers of OPC and oligodendrocytes no treatment effects were found. In summary, minocycline treatment diminished the course of demyelination in the grey and white matter and prevented disturbances in motor coordination.

  16. Beneficially reusing LLRW the Savannah River Site Stainless Steel Program

    International Nuclear Information System (INIS)

    Boettinger, W.L.

    1993-01-01

    With 68 radioactively contaminated excess Process Water Heat Exchangers the Savannah River Site launched its program to turn potential LLRW metal liabilities into assets. Each Heat Exchanger contains approximately 100 tons of 304 Stainless Steel and could be disposed as LLRW by land burial. Instead the 7000 tons of metal will be recycled into LLRW, HLW, and TRU waste containers thereby eliminating the need for near term land disposal and also eliminating the need to add more clean metal to the waste stream. Aspects of the partnership between DOE and Private Industry necessary to accomplish this new mission are described. A life cycle cost analysis associated with past practices of using carbon steel containers to indefinitely store material (contributing to the creation of today's legacy waste problems) is presented. The avoided cost calculations needed to support the economics of the ''Indifference'' decision process in assessing the Beneficial Reuse option relative to the Burial option are described

  17. Glutamine Supplementation in Sick Children: Is It Beneficial?

    Directory of Open Access Journals (Sweden)

    Elise Mok

    2011-01-01

    Full Text Available The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evidence is available on the benefits of Gln supplementation in pediatric patients. This includes premature infants, infants with gastrointestinal disease, children with Crohn's disease, short bowel syndrome, malnutrition/diarrhea, cancer, severe burns/trauma, Duchenne muscular dystrophy, sickle cell anemia, cystic fibrosis, and type 1 diabetes. Moreover, methodological issues have been noted in some studies. Further mechanistic data is needed along with large randomized controlled trials in select populations of sick children, who may eventually benefit from supplemental Gln.

  18. Resolving the controversy over beneficial effects of ionizing radiation

    International Nuclear Information System (INIS)

    Cuttler, J.M.

    1999-01-01

    In spite of the extensive research carried out during the past century, intense controversy continues over the health effects of low-level radiation. This controversy is largely due to political, social and economic issues among scientists and analysts in a variety of disciplines. These issues cloud objectivity and strengthen paradigms. Over the past ten years, in 14 universities and two research institutes, Japanese scientists have conducted exceptional research which clearly demonstrates beneficial effects of low-level radiation and cancer cures following therapy with low doses of radiation. Assessment, replication and extension of this work in North America could lead to greater appreciation of its significance. Cancer patients would demand such treatments, leading to universal acceptance of these bio-positive effects and reducing public fear of nuclear technology. (author)

  19. Acceptance for Beneficial Use Pumping Instrumentation and Control Skid L

    International Nuclear Information System (INIS)

    KOCH, M.R.

    1999-01-01

    This is a final Acceptance for Beneficial Use (ABU) for Pumping and Instrumentation Control (PIC) skid ''L''. PIC skid ''L'' is ready for pumping tank U-105. All the testing and documentation has been completed as required on the ABU checklist. This ABU covers only the readiness of the PIC skid ''L''. Other U-farm preparations including dilution tank fabrication, portable exhauster readiness, leak detection, valve pit preparation, and the Operation Control Station readiness are not part of this ABU. PIC skid ''L'' is a new skid fabricated and tested at Site Fabrication Services. The skid controls the jet pump and monitors various instruments associated with the pumping operation. This monitoring includes leak detection along the waste transfer route and flammable gases in the pump pit

  20. Beneficiation studies of an uranium siliceous - phosphate ore

    International Nuclear Information System (INIS)

    Bruno, J.B.; Santos, A.T.; Santos Benedetto, J. dos

    1980-01-01

    The consolidation of the beneficiation studies of a low-grade uranium siliceous - phosphate ore (11% P 2 O 5 ) from Itataia region in the Northeast of Brazil, owned by Empresas Nucleares Brasileiras S.A. - NUCLEBRAS, are presented. Laboratory studies using froth flotation technique and applying statistical methods for data evaluation were made. Pilot plant tests in a 120 Kg/h scale were conducted as a consequence of the bench scale tests. The developed process using tall-oil as collector and starch as depressant gave a total yield of 80% for the P 2 O 5 and 71% the U 3 O 8 , for a 33% P 2 O 5 phosphate concentrate. (Author) [pt

  1. Is a strong sense of self-efficacy always beneficial?

    Directory of Open Access Journals (Sweden)

    Thomas VERHAEREN

    2012-01-01

    Full Text Available The concept of self-efficacy, introduced by Albert Bandura, has received a lot of attention in psychological research. This comes as no surprise, as it encompasses a person's beliefs about his or her capabilities to successfully do what is necessary for desired goals, which is a central mechanism in human agency. The concept has been linked to many outcomes (e.g. motivation and performance, almost exclusively yielding positive results. Recently, however, arguments have risen that a strong sense of selfefficacy may not always be as beneficial as presumed until now. In this article, I review the core of the positive literature on self-efficacy and highlight studies that question and oppose the dominance of these positive self-efficacy associations. Implications for future research, emphasizing the need of a different research approach, are mentioned.

  2. Beneficial uses program. Progress report, Period ending September 30, 1976

    International Nuclear Information System (INIS)

    1976-11-01

    Progress is reported in the development of a technology to utilize 137 Cs, a nuclear power plant by-product, as a γ source for the treatment of sewage sludge for use as a fertilizer or animal feed supplement. Results are reported from studies on the radiosensitivity of Escherichia coli and Salmonella in sewage sludge; the effects of ammonia on the survival of viruses in sludges; heat inactivation rates for bacteria in sludges; the combined effects of heat and radiation on odor from sludge; and the cost advantages of irradiation over heat treatment of sewage sludge. Animal studies demonstrated the nutritional advantages of the addition of sludge to animal feeds and plant studies demonstrated the beneficial effects on plant growth of the use of sludge as fertilizer

  3. Beneficiation and extraction of nonterrestrial materials, part 2

    Science.gov (United States)

    Agosto, William N.

    A review of options for processing extraterrestrial materials was dominated by industrial materials scientist who tried to identify which processes utilizing space materials could be implemented in the near term. The most practical process seem to us to be the extraction of lunar oxygen and the extraction of metals and ceramics from the residues of the reduction process. The growth of space activity will be accompanied by increased demand for liquid oxygen for each round trip to the Moon. The oxygen and the intermediary product water will be needed for the life support at the base. The reduced metals and ceramics may be considered byproducts or may develop into primary products. Some of the same processes would be directly applicable to recovery of products from asteroids. We also discussed other processes for directly utilizing asteroid metals. Some of the topics covered include beneficiation and oxygen extraction methods, metallurgy, and extraterrestrial cement.

  4. Technology for beneficiation of non-coking coals

    Energy Technology Data Exchange (ETDEWEB)

    Bose, S.K.

    1987-04-01

    This article outlines the need for efficient non-coking coal beneficiation plants in India to cope with mass production from opencast coal mines. The existing use of magnetite in heavy medium separation processes is expensive and not very efficient in respect to removing shales from opencast lump coals. Instead a new technique is proposed using a ROMJIG washing plant developed in the Federal Republic of Germany. This provides a very efficient, low cost washing system for the coals and allows the continued integration with the coal blending plants. This simplified technology allows for flexible working hours to meet demand and will allow new developments to continue including fuel slurry pipelines, automated testing of coals and new pulverized boiler fuels.

  5. ASSESSING OF HERBIVOROUS AND BENEFICIAL INSECTS ON SWITCHGRASS IN UKRAINE.

    Science.gov (United States)

    Stefanovska, T; Kucherovska, S; Pisdlisnyuk, V

    2014-01-01

    A perennial switchgrass, (Panicum virgatum L.), (C4) that is native to North America has good potential for biomass production because of its wide geographic distribution and adaptability to diverse environmental conditions. Insects can significantly impact the yield and quality of biofuel crops. If switchgrass are to be grown on marginally arable land or in monoculture, it are likely to be plagued with herbivore pests and plant diseases at a rate that exceeds what would be expected if the plants were not stressed in this manner. This biofuel crop has been under evaluation for commercial growing in Ukraine for eight years. However, insect diversity and the potential impact of pests on biomass production of this feedstock have not been accessed yet. The objective of our study, started in 2011, is a survey of switch grass insects by trophic groups and determine species that have pest status at two sites in the Central part of Ukraine (Kiev and Poltava regions). In Poltava site we investigated the effect of nine varieties of switchgrass (lowland and upland) to insects' diversity. We assessed changes over time in the densities of major insects' trophic groups, identifying potential pests and natural enemies. Obtained results indicates that different life stages of herbivorous insects from Hymenoptera, Homoptera, Diptera and Coleoptera orders were present on switchgrass during the growing season. Our study results suggests that choice of variety has an impact on trophic groups' structure and number of insects from different orders on swicthgrass. Herbivores and beneficial insects were the only groups that showed significant differences across sampling dates. The highest population of herbivores insects we recorded on 'Alamo' variety for studied years, although herbivore diversity tended to increase on 'Shelter', 'Alamo' and 'Cave-in-Rock' during 2012 and 2013. 'Dacotah', 'Nebraska', 'Sunburst', 'Forestburg' and 'Carthage' showed the highest level of beneficial insects

  6. Beneficial Effects of Green Tea Catechins on Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Monira Pervin

    2018-05-01

    Full Text Available Tea is one of the most consumed beverages in the world. Green tea, black tea, and oolong tea are made from the same plant Camellia sinensis (L. O. Kuntze. Among them, green tea has been the most extensively studied for beneficial effects on diseases including cancer, obesity, diabetes, and inflammatory and neurodegenerative diseases. Several human observational and intervention studies have found beneficial effects of tea consumption on neurodegenerative impairment, such as cognitive dysfunction and memory loss. These studies supported the basis of tea’s preventive effects of Parkinson’s disease, but few studies have revealed such effects on Alzheimer’s disease. In contrast, several human studies have not reported these favorable effects with regard to tea. This discrepancy may be due to incomplete adjustment of confounding factors, including the method of quantifying consumption, beverage temperature, cigarette smoking, alcohol consumption, and differences in genetic and environmental factors, such as race, sex, age, and lifestyle. Thus, more rigorous human studies are required to understand the neuroprotective effect of tea. A number of laboratory experiments demonstrated the benefits of green tea and green tea catechins (GTCs, such as epigallocatechin gallate (EGCG, and proposed action mechanisms. The targets of GTCs include the abnormal accumulation of fibrous proteins, such as Aβ and α-synuclein, inflammation, elevated expression of pro-apoptotic proteins, and oxidative stress, which are associated with neuronal cell dysfunction and death in the cerebral cortex. Computational molecular docking analysis revealed how EGCG can prevent the accumulation of fibrous proteins. These findings suggest that GTCs have the potential to be used in the prevention and treatment of neurodegenerative diseases and could be useful for the development of new drugs.

  7. [Changes in Cell Surface Properties and Biofilm Formation Efficiency in Azospirillum brasilense Sp245 Mutants in the Putative Genes of Lipid Metabolism mmsB1 and fabG1].

    Science.gov (United States)

    Shumilova, E; Shelud'ko, A V; Filip'echeva, Yu A; Evstigneeva, S S; Ponomareva, E G; Petrova, L P; Katsy, E I

    2016-01-01

    The previously obtained insertion mutants ofAzospirillum brasilense Sp245 in the genes mmsBl and fabG1 (strains SK039 and Sp245.1610, respectively) were characterized by impaired flagellation and motility. The putative products of expression of these genes are 3-hydroxyisobutyrate dehydrogenase and 3-oxoacyl-[acyl-carrier protein] reductase, respectively. In the present work, A. brasilense- Sp245 strains SK039 and Sp245.1610 were found to have differences in the content of 3-hydroxyhexadecanoic, hexadecanoic, 3-hydroxytetradecanoic, hexadecenoic, octadecenoic, and nonadecanoic acids in their lipopolysaccharide prepa- rations, as well as in cell hydrophobicity and hemagglutination activity and dynamics of cell aggregation, in biomass amount, and in the relative content of lipopolysaccharide antigens in mature biofilms formed on hydrophilic or hydrophobic surfaces.

  8. Coberturas vegetais, doses de nitrogênio e inoculação de sementes com Azospirillum brasilense em arroz de terras altas no sistema plantio direto Cover crops, nitrogen rates and seeds inoculation with Azospirillum brasilense in upland rice under no-tillage

    Directory of Open Access Journals (Sweden)

    Douglas de Castilho Gitti

    2013-01-01

    Full Text Available O arroz é importante fonte de energia e proteínas para a população mundial, principalmente na Ásia e Oceania. No Brasil, juntamente com o feijão, constitui a base da alimentação. Tecnologias sustentáveis que reduzam custos da produção e aumentem a produtividade do arroz podem garantir seu suprimento em períodos de alta demanda. O objetivo deste trabalho foi avaliar diferentes coberturas vegetais antecessoras (milheto [Pennisetum americanum], crotalária [Crotalaria juncea], guandu [Cajanus cajan], braquiária [Brachiaria ruziziensis], milheto + crotalária e milheto + guandu, doses de nitrogênio (N em cobertura (0, 40, 80 e 120 kg ha-1 e o efeito da inoculação de sementes com Azospirillum brasilense no arroz de terras altas em sistema plantio direto no desenvolvimento e na produtividade. Utilizou-se o delineamento experimental em blocos casualizados em esquema fatorial 6x4x2 com quatro repetições. O estudo foi desenvolvido em um Latossolo Vermelho, em Selvíria, Estado do Mato Grosso do Sul, Brasil, em 2011/2012. O cultivo do guandu antecedendo o arroz proporcionou maior produtividade do arroz somente em comparação a B. ruziziensi. A produtividade do arroz em função das doses de N em cobertura se ajustou a uma função quadrática. Não houve influência da inoculação de sementes com A. brasilense sobre a produtividade do arroz, porém houve interação entre a inoculação e as coberturas vegetais sobre o teor de N foliar, número de panículas por m², matéria seca de plantas de arroz e a massa de cem grãos.Rice is an important source of energy and protein for the world population, mainly in Asia and Oceania. In Brazil, together with common beans, it is the population's basic food. Sustainable technologies that reduce rice production costs and increase productivity can warrant its supply on period of high demand. The objective of this study was to evaluate different preceding cover crops (millet [Pennisetum americanum

  9. Identificação de isolados de Azospirillum amazonense associados a Brachiaria spp., em diferentes épocas e condições de cultivo e produção de fitormônio pela bactéria Identification of Azospirillum amazonense isolates associated to Brachiaria spp. at different stages and growth conditions, and bacterial plant hormone production

    Directory of Open Access Journals (Sweden)

    F. B. Reis Junior

    2004-02-01

    Full Text Available Existem evidências de que pastagens formadas por algumas espécies do gênero Brachiaria poderiam beneficiar-se com o processo de fixação biológica do nitrogênio atmosférico (FBN, garantindo a estas pastagens maior longevidade. Dentre as bactérias diazotróficas encontradas em associação com estas gramíneas forrageiras, destaca-se a espécie Azospirillum amazonense. Neste trabalho, objetivou-se verificar a influência da espécie de Brachiaria, manejo da pastagem e sazonalidade sobre as populações de A. amazonense associadas às raízes destas plantas. Diferentes pastagens (B. humidicola, B. decumbens e B. brizantha foram introduzidas em regiões do ecossistema Cerrado e de Mata Atlântica. Foram avaliados dois sistemas de manejo com diferentes taxas de lotação, e as coletas foram realizadas em diferentes épocas do ano. As populações de A. amazonense foram quantificadas e a identidade dos isolados confirmada, assim como sua capacidade de produção de fitormônios tipo AIA (ácido 3-indol acético em meio de cultivo. Isolados de A. amazonense foram obtidos a partir de amostras de raízes das três espécies de Brachiaria avaliadas. Estimativas das populações desta bactéria variaram de 10³-10(7 células g-1 de raízes. Em amostras do ecossistema Cerrado, a época de coleta apresentou efeito significativo sobre a população destas bactérias. Os dados da região de Mata Atlântica mostraram que plantas de Brachiaria de diferentes espécies e pastagens sob diferentes taxas de lotação podem apresentar números populacionais distintos associados às suas raízes. A técnica de análise de restrição do DNA ribossomal amplificado (ARDRA confirmou a identidade de todos os isolados avaliados. Estes isolados foram capazes de produzir fitormônios tipo AIA.There is evidence that pastures formed by some species of the genus Brachiaria could be benefited by the biological nitrogen fixation process (BNF, which would give these

  10. Coberturas vegetais, doses de nitrogênio e inoculação de sementes com Azospirillum brasilense em arroz de terras altas no sistema plantio direto Cover crops, nitrogen rates and seeds inoculation with Azospirillum brasilense in upland rice under no-tillage

    Directory of Open Access Journals (Sweden)

    Douglas de Castilho Gitti

    2012-01-01

    Full Text Available O arroz é importante fonte de energia e proteínas para a população mundial, principalmente na Ásia e Oceania. No Brasil, juntamente com o feijão, constitui a base da alimentação. Tecnologias sustentáveis que reduzam custos da produção e aumentem a produtividade do arroz podem garantir seu suprimento em períodos de alta demanda. O objetivo deste trabalho foi avaliar diferentes coberturas vegetais antecessoras (milheto [Pennisetum americanum], crotalária [Crotalaria juncea], guandu [Cajanus cajan], braquiária [Brachiaria ruziziensis], milheto + crotalária e milheto + guandu, doses de nitrogênio (N em cobertura (0, 40, 80 e 120 kg ha-1 e o efeito da inoculação de sementes com Azospirillum brasilense no arroz de terras altas em sistema plantio direto no desenvolvimento e na produtividade. Utilizou-se o delineamento experimental em blocos casualizados em esquema fatorial 6x4x2 com quatro repetições. O estudo foi desenvolvido em um Latossolo Vermelho, em Selvíria, Estado do Mato Grosso do Sul, Brasil, em 2011/2012. O cultivo do guandu antecedendo o arroz proporcionou maior produtividade do arroz somente em comparação a B. ruziziensi. A produtividade do arroz em função das doses de N em cobertura se ajustou a uma função quadrática. Não houve influência da inoculação de sementes com A. brasilense sobre a produtividade do arroz, porém houve interação entre a inoculação e as coberturas vegetais sobre o teor de N foliar, número de panículas por m², matéria seca de plantas de arroz e a massa de cem grãos.Rice is an important source of energy and protein for the world population, mainly in Asia and Oceania. In Brazil, together with common beans, it is the population's basic food. Sustainable technologies that reduce rice production costs and increase productivity can warrant its supply on period of high demand. The objective of this study was to evaluate different preceding cover crops (millet [Pennisetum americanum

  11. A Genetic System for the Thermophilic Acetogenic Bacterium Thermoanaerobacter kivui.

    Science.gov (United States)

    Basen, Mirko; Geiger, Irina; Henke, Laura; Müller, Volker

    2018-02-01

    Thermoanaerobacter kivui is one of the very few thermophilic acetogenic microorganisms. It grows optimally at 66°C on sugars but also lithotrophically with H 2 + CO 2 or with CO, producing acetate as the major product. While a genome-derived model of acetogenesis has been developed, only a few physiological or biochemical experiments regarding the function of important enzymes in carbon and energy metabolism have been carried out. To address this issue, we developed a method for targeted markerless gene deletions and for integration of genes into the genome of T. kivui The strain naturally took up plasmid DNA in the exponential growth phase, with a transformation frequency of up to 3.9 × 10 -6 A nonreplicating plasmid and selection with 5-fluoroorotate was used to delete the gene encoding the orotate phosphoribosyltransferase ( pyrE ), resulting in a Δ pyrE uracil-auxotrophic strain, TKV002. Reintroduction of pyrE on a plasmid or insertion of pyrE into different loci within the genome restored growth without uracil. We subsequently studied fructose metabolism in T. kivui The gene fruK (TKV_c23150) encoding 1-phosphofructosekinase (1-PFK) was deleted, using pyrE as a selective marker via two single homologous recombination events. The resulting Δ fruK strain, TKV003, did not grow on fructose; however, growth on glucose (or on mannose) was unaffected. The combination of pyrE as a selective marker and the natural competence of the strain for DNA uptake will be the basis for future studies on CO 2 reduction and energy conservation and their regulation in this thermophilic acetogenic bacterium. IMPORTANCE Acetogenic bacteria are currently the focus of research toward biotechnological applications due to their potential for de novo synthesis of carbon compounds such as acetate, butyrate, or ethanol from H 2 + CO 2 or from synthesis gas. Based on available genome sequences and on biochemical experiments, acetogens differ in their energy metabolism. Thus, there is an

  12. Ecological enrichment in agroecosystems: Utilizing wildflowers to promote beneficial arthropod communities

    Science.gov (United States)

    Beneficial arthropods which provide important ecosystems services have come under threat as a result of intensive agricultural practices and landscape simplification. Engineering diverse heterogeneous agricultural landscapes to provide optimal resources for beneficial arthropods may recover and enha...

  13. Antibacterial Property of a Coral-Associated Bacterium Pseudoalteromonas luteoviolacea Against Shrimp Pathogenic Vibrio harveyi (In Vitro Study)

    OpenAIRE

    OCKY KARNA RADJASA; TORBEN MARTENS; HANS-PETER GROSSART; AGUS SABDONO; MEINHARD SIMON; TONNY BACHTIAR

    2005-01-01

    A coral-associated bacterium was successfully screened for secondary metabolites production based on PCR amplification of the nonribosomal peptide synthetase gene and was identified as closely related to Pseudoalteromonas luteoviolacea based on its 16S rDNA. The bacterium was found to inhibit the growth of shrimp pathogenic bacterium tested, Vibrio harveyi. To characterize the inhibiting metabolite, a 279 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved s...

  14. 17 CFR 229.403 - (Item 403) Security ownership of certain beneficial owners and management.

    Science.gov (United States)

    2010-04-01

    ... of certain beneficial owners and management. 229.403 Section 229.403 Commodity and Securities... Management and Certain Security Holders § 229.403 (Item 403) Security ownership of certain beneficial owners and management. (a) Security ownership of certain beneficial owners. Furnish the following information...

  15. Beneficial effects of the Mediterranean diet on metabolic syndrome.

    Science.gov (United States)

    Grosso, Giuseppe; Mistretta, Antonio; Marventano, Stefano; Purrello, Agata; Vitaglione, Paola; Calabrese, Giorgio; Drago, Filippo; Galvano, Fabio

    2014-01-01

    The metabolic syndrome (MetS) represents a cluster of medical disorders, such as hyperglycemia, dyslipidemia, hypertension, and abdominal obesity that, when occurring together, increase the risk of developing cardiovascular disease. The role of food and nutrients in the aetiology of chronic diseases has become clearer over the last 15 years. In this review we collected evidence on the beneficial impact of the Mediterranean diet on MetS by analyzing epidemiological reports documenting its prevalence in subjects who have adopted this dietary pattern. We also explored the role of the individual components of the diet on the specific aspects characterizing the MetS (i.e. metabolic indices, body weight and blood pressure). There is ample evidence showing that subjects adherent to the Mediterranean diet have lower prevalence and incidence rates of MetS than non-adherent. Moreover, it has been widely documented that specific components of this dietary pattern play a role in the prevention of several morbid conditions related to the MetS.

  16. Beneficial Effects of Temperate Forage Legumes that Contain Condensed Tannins

    Directory of Open Access Journals (Sweden)

    Jennifer W. MacAdam

    2015-07-01

    Full Text Available The two temperate forage legumes containing condensed tannins (CT that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT and sainfoin (Onobrychis viciifolia Scop.; SF. Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kg−1 dry matter (DM, while SF contains 30 to 80 g·CT·kg−1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb. Dumort. forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity.

  17. Stainless Steel RSM Beneficial Reuse technical feasibility to business reality

    International Nuclear Information System (INIS)

    Boettinger, W.L.; Mishra, G.

    1997-08-01

    The Stainless Steel Beneficial Reuse Program began in 1994 as a demonstration funded by the DOE Office of Science and Technology. The purpose was to assess the practicality of stainless steel radioactive scrap metal (RSM) recycle. Technical feasibility has been demonstrated through the production of a number of products made from recycled RSM. A solid business foundation is yet to be achieved. However, a business environment is beginning to develop as multiple markets and applications for RSM are surfacing around the Complex. The criteria for a successful business reality includes: - affordable programs, - a continuing production base from which to expand, - real products needs, -adequate RSM supply, and - a multi-year program This program currently sponsored by SRS and DOE-ORO to fabricate Defense Waste Processing Facility (DWPF) canisters from RSM provides an activity that satisfies these criteria. The program status is discussed. A comparison of the cost of DWPF canisters fabricated from recycled RSM and virgin metal is presented. The comparison is a function of several factors: disposal costs, the fabrication cost of virgin metal canisters, the fabrication cost of recycled RSM canisters, free release decontamination costs, and the cost to accumulate the RSM. These variables are analyzed and the relationship established to show the break-even point for various values of each parameter

  18. Beneficial uses program. Progress report, period ending 31 December 1975

    International Nuclear Information System (INIS)

    1976-02-01

    Progress is reported on studies designed to develop the necessary technologies for cost-beneficial uses of existing and future surplus radioactive materials. The purpose of the Waste Resources Utilization Program is to develop a technology to utilize cesium-137, a nuclear power plant by-product, to modify sewage sludge for safe application as a fertilizer or as an animal feed supplement. A major portion of the effort this quarter was directed toward establishment of thermoradiation treatment levels for elimination of pathogenic organisms in sludge. Three groups of pathogenic microorganisms are being studied: viruses, bacteria, and parasites. Other areas of study included physical-chemical properties of thermoradiation treated sewage sludge such as ''settling'' and ''filterability'' and pilot plant design for a plant to thermoradiate up to 75 kiloliters of sludge per day. In the Separation Technology and Source Development Program previous work has demonstrated the feasibility of applying the Sandia Solidification Process to the recovery of radiocesium from high-level liquid wastes. The influence of various parameters on 137 Cs source intensities was explored. A multiple ceramic 137 Cs source package was found to be essentially the same from a radiation process viewpoint as a single 137 Cs source. The tolerable impurity levels in the ceramic sources, in terms of perturbation of the gamma flux, are relatively high (a few percent)

  19. Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review

    Directory of Open Access Journals (Sweden)

    Meerza Abdul Razak

    2017-01-01

    Full Text Available Glycine is most important and simple, nonessential amino acid in humans, animals, and many mammals. Generally, glycine is synthesized from choline, serine, hydroxyproline, and threonine through interorgan metabolism in which kidneys and liver are the primarily involved. Generally in common feeding conditions, glycine is not sufficiently synthesized in humans, animals, and birds. Glycine acts as precursor for several key metabolites of low molecular weight such as creatine, glutathione, haem, purines, and porphyrins. Glycine is very effective in improving the health and supports the growth and well-being of humans and animals. There are overwhelming reports supporting the role of supplementary glycine in prevention of many diseases and disorders including cancer. Dietary supplementation of proper dose of glycine is effectual in treating metabolic disorders in patients with cardiovascular diseases, several inflammatory diseases, obesity, cancers, and diabetes. Glycine also has the property to enhance the quality of sleep and neurological functions. In this review we will focus on the metabolism of glycine in humans and animals and the recent findings and advances about the beneficial effects and protection of glycine in different disease states.

  20. Can vineyard biodiversity be beneficial for viticulture and tourism?

    Science.gov (United States)

    Hervé, Morgane; Kratschmer, Sophie; Gregorich, Claudia; Silvia, Winter; Montembault, David; Zaller, Johann G.; Guernion, Muriel; Jung, Vincent; Schuette, Rebekka; Paredes, Daniel; Guzman Diaz, Gema; Cabezas Luque, Jose Manuel; Hoble, Adela; Popescu, Daniela; Burel, Françoise; Cluzeau, Daniel; Bergmann, Holger; Potthoff, Martin; Nicolai, Annegret

    2017-04-01

    The European research BiodivERsA project VineDivers aims to link ecosystem services and vine production, in an integrative approach that considers both landscape structure and cultural practices (cover-crops versus bare soils), in vineyards of Austria, France, Romania and Spain. Such services studied are (i) provisioning and regulation services by soil biota and pollinators, and (ii) landscape cultural services. In this study, we want to know if landscape beneficial for biodiversity providing ecosystem services at a plot scale also have an aesthetical value. An interdisciplinary approach was chosen to include both ecological and sociological data. First, we analyzed the influence of soil management practices and landscape complexity on soil biota, inter-row flora and bees. Second, we implemented a questionnaire based on photographs about biodiversity perception and visual aesthetic evaluation. Our results highlighted the effect of landscape complexity and soil management intensity on biodiversity and their ecological and cultural ecosystem services. This allows us to discuss the global importance of biodiversity for a wine-producing region. Further analysis within the VineDivers project will focus on an assessment of the biodiversity importance for local viticulture economy.

  1. Beneficial effects of Psidium guajava leaf extract on diabetic myocardium.

    Science.gov (United States)

    Soman, Sowmya; Rajamanickam, Chellam; Rauf, Arun A; Indira, Madambath

    2013-01-01

    Non enzymatic glycosylation (glycation) between reducing sugar and protein results in the formation of advanced glycation end products (AGEs), which is believed to play an important role in diabetes associated cardiovascular complications. Thus agents that inhibit the formation of AGEs are believed to have therapeutic potential against diabetic complications. In the present study we evaluated the antiglycative potential of ethyl acetate fraction of Psidium guajava leaves (PGEt) by administering the extract into streptozotocin induced diabetic rats. Daily administration of the extract for a period of one month significantly decreased the blood glucose, glycated hemoglobin and fructosamine levels in a dose dependent manner. Evaluation of the toxicity markers like SGOT and SGPT revealed the non toxic nature of the extract. Apart from this we evaluated the presence of cardiac isoform of liver alpha 2 macroglobulin, which is a major protein associated with earlier stages of cardiac hypertrophy. SDS-PAGE analysis showed that the level of this protein decreased significantly in extract treated groups compared to diabetic control. These findings support that the administration of PGEt extract may be beneficial for preventing cardiovascular complications associated with diabetes. Copyright © 2011 Elsevier GmbH. All rights reserved.

  2. THE BENEFICIAL EFFECT OF BILINGUALISM IN VISUAL MEDIA

    Directory of Open Access Journals (Sweden)

    Aliva Rosdiana

    2017-04-01

    Full Text Available Bilingualism is a phenomenon that affects people throughout the world. People use bilingualism in particular situations in society such as in education, job, mass media, etc. People who speak bilingualism means that they get second language learning. Radio, televison, and YouTube are important vehicles of mass communication. Mass communication differs from the studies of other forms of communication, such as interpersonal communication, in that it focuses on a single source transmitting information to a large group of receivers. The study of bilingualism in visual media is chiefly concerned with how the content of visual media persuades or otherwise affects either behavior, attitude, opinion, or emotion of the person or people receiving the information. The beneficial effect is the development of bilingualism. Watching video affects children‘s acquisition of their native language and hasten language shift to the majority language. By watching the video, it also enrich our knowledge to particular vocabularies based on particular topics. The Internet makes it possible to have conversations across countries and continents. Individuals have multiple identities and belong to other speakers of their heritage language. So, the linguistic competence will develop as a by-product of the interest. In addition, it brings people closer.

  3. Characterisation of Bone Beneficial Components from Australian Wallaby Bone

    Science.gov (United States)

    Lao, Weiguo; Jin, Xingliang; Tan, Yi; Xiao, Linda; Padula, Matthew P.; Bishop, David P.; Reedy, Brian; Ong, Madeleine; Kamal, Mohammad A.; Qu, Xianqin

    2016-01-01

    Background: Osteoporosis is a condition in which the bones become brittle, increasing the risk of fractures. Complementary medicines have traditionally used animal bones for managing bone disorders, such as osteoporosis. This study aimed to discover new natural products for these types of conditions by determining mineral and protein content of bone extracts derived from the Australian wallaby. Methods: Inductively coupled plasma-mass spectrometry and Fourier transform infrared spectroscopic analysis were used for mineral tests, proteome analysis was using LC/MS/MS and the effects of wallaby bone extracts (WBE)s on calcium deposition and alkaline phosphatase activity were evaluated in osteogenic cells derived from adipose tissue-derived stem cells (ADSCs). Results: Concentrations of calcium and phosphorus were 26.21% and 14.72% in WBE respectively. Additionally, minerals found were wide in variety and high in concentration, while heavy metal concentrations of aluminium, iron, zinc and other elements were at safe levels for human consumption. Proteome analysis showed that extracts contained high amounts of bone remodelling proteins, such as osteomodulin, osteopontin and osteoglycin. Furthermore, in vitro evaluation of WBEs showed increased deposition of calcium in osteoblasts with enhanced alkaline phosphatase activity in differentiated adipose-derived stem cells. Conclusion: Our results demonstrate that wallaby bone extracts possess proteins and minerals beneficial for bone metabolism. WBEs may therefore be used for developing natural products for conditions such as osteoporosis and further investigation to understand biomolecular mechanism by which WBEs prevent osteoporosis is warranted. PMID:28930133

  4. Can misfolded proteins be beneficial? The HAMLET case.

    Science.gov (United States)

    Pettersson-Kastberg, Jenny; Aits, Sonja; Gustafsson, Lotta; Mossberg, Anki; Storm, Petter; Trulsson, Maria; Persson, Filip; Mok, K Hun; Svanborg, Catharina

    2009-01-01

    By changing the three-dimensional structure, a protein can attain new functions, distinct from those of the native protein. Amyloid-forming proteins are one example, in which conformational change may lead to fibril formation and, in many cases, neurodegenerative disease. We have proposed that partial unfolding provides a mechanism to generate new and useful functional variants from a given polypeptide chain. Here we present HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) as an example where partial unfolding and the incorporation of cofactor create a complex with new, beneficial properties. Native alpha-lactalbumin functions as a substrate specifier in lactose synthesis, but when partially unfolded the protein binds oleic acid and forms the tumoricidal HAMLET complex. When the properties of HAMLET were first described they were surprising, as protein folding intermediates and especially amyloid-forming protein intermediates had been regarded as toxic conformations, but since then structural studies have supported functional diversity arising from a change in fold. The properties of HAMLET suggest a mechanism of structure-function variation, which might help the limited number of human protein genes to generate sufficient structural diversity to meet the diverse functional demands of complex organisms.

  5. Review of produced water recycle and beneficial reuse

    Energy Technology Data Exchange (ETDEWEB)

    Hum, F.; Tsang, P. [Calgary Univ., AB (Canada). Tomographic Imaging and Porous Media Laboratory; Harding, T. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering; Kantzas, A. [Calgary Univ., AB (Canada). Tomographic Imaging and Porous Media Laboratory]|[Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering

    2006-11-15

    Fresh water scarcity and increasing water demands are concerns facing jurisdictions around the world. A number of water management initiatives involving produced water recycling and reuse in Alberta and Canada will have a significant impact on sustainable development in Alberta. Produced water must first be treated to meet water quality requirements and regulatory guidelines for specific applications. This paper presented a comprehensive technical and economic review of commercially available water treatment technologies and discussed technical challenges in recycling produced water for steam generation and for commercial use. It provided an introduction to fresh water allocations and oil, gas and water production volumes in Alberta. In addition to research and development activities, the paper identified guidelines from Alberta Environment and the Energy and Utilities Board. Benefits of treated produced water were discussed. Desalination technologies include both distillation processes and membrane processes. The paper provided cost estimates based on a literature view and discussed the potential water treatment for south-east Alberta. The paper also offered a number of recommendations for further research. It was concluded that treating and recycling produced water for agriculture, irrigation, commercial and domestic uses are at early stages of research and development and that regulatory guidelines on water quality, health and safety for specific industries, ownership and transfer of produced water need to be developed in order to facilitate beneficial reuse of produced water. 57 refs., 7 tabs., 14 figs.

  6. EFECTO DE LA INOCULACIÓN DE Azospirillum halopraeferens Y Bacillus amyloliquefaciens EN LA GERMINACIÓN DE Prosopis chilensis

    Directory of Open Access Journals (Sweden)

    J.A. Villegas-Espinoza

    2009-07-01

    Full Text Available Las Bacterias Promotoras de Crecimiento de Plantas (BPCP, son microorganismos fijadores de nitrógeno atmosférico y a su vez producen hormonas que aprovechan las plantas para llevar a cabo su desarrollo. Es importante la utilización de microorganismos benéficos para reducir la fertilización química. La investigación científica ha incrementado la busqueda y aislamiento de BPCP de regiones especificas como son las zonas áridas, ya que estos microorganismos estan adaptados a ambientes extremos. La especie Prosopis chilensis esta siendo utilizada para reforestación de escuelas, parques y también como ornato; para reproducir esta planta se esta utilizando fertilizantes químicos que son dañinos al medio ambiente. El objetivo de la presente investigación, consistió en analizar el efecto promotor de las bacterias promotoras del crecimiento vegetal Bacillus amyloliquefaciens y Azospirillum halopraeferens en la germinación y emergencia del mezquite chileno (P. chilensis bajo cuatro concentraciones salinas (0, 0.25, 0.5 y 0.75 M de NaCl. Se obtuvieron semillas de mezquite chileno de la región de Santa Ana, Sonora, México. Bajo condiciones de laboratorio se evaluó el porcentaje de germinación, tasa de germinación, altura, longitud radicular de plántula, peso fresco de plántula número de células bacterianas adheridas al sistema radicular. Bajo condiciones de invernadero, las variables evaluadas fueron porcentaje de emergencia, tasa de emergencia, altura y longitud radicular, peso fresco y seco de planta, peso fresco y seco de raíz, número de células bacterianas adheridas al sistema radicular. Los resultados indican que, bajo condiciones in vitro, el porcentaje y tasa de germinación disminuyó conforme la salinidad se incrementa. Sin embargo, estas variables fueron afectadas positivamente por A. halopraeferens y B. amyloliquefaciens en comparación del tratamiento

  7. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Mun Su [University of Florida, Gainesville; Moritz, Brelan E. [University of Florida, Gainesville; Xie, Gary [Los Alamos National Laboratory (LANL); Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Chertkov, Olga [Los Alamos National Laboratory (LANL); Brettin, Thomas S [ORNL; Han, Cliff [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Patel, Milind [University of Florida, Gainesville; Ou, Mark [University of Florida, Gainesville; Harbrucker, Roberta [University of Florida, Gainesville; Ingram, Lonnie O. [University of Florida; Shanmugam, Keelnathan T. [University of Florida

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer- ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this spo- rogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attrac- tive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi- cellulose. This bacterium is also considered as a potential probiotic. Complete genome se- quence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  8. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Gary [Los Alamos National Laboratory (LANL); Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Chertkov, Olga [Los Alamos National Laboratory (LANL); Land, Miriam L [ORNL

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 C and pH 5.0 and fer-ments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemi-cellulose. This bacterium is also considered as a potential probiotic. Complete genome squence of a representative strain, B. coagulans strain 36D1, is presented and discussed.

  9. Moritella viscosa, a pathogenic bacterium affecting the fillet quality in fish

    DEFF Research Database (Denmark)

    Ingerslev, Hans-Christian; Nielsen, Michael Engelbrecht

    2011-01-01

    Moritella viscosa is a bacterium belonging to the family Moritellaceae and was formerly known as Vibrio viscosus. The name ‘viscosa’ originates from the slimy nature of the bacterium. M. viscosa is considered to be the main causative agent of the phenomenon ‘winter ulcer’ or ‘cold-water ulcer......’ which affects various fish species in seawater during cold periods (Lunder et al. 1995). The bacterium is mainly a problem for farmed salmonid species, such as Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss), but has also been isolated from other fish species, including Atlantic...... market price because of a quality downgrade caused by textural changes in the fillet....

  10. Complete Genome Sequence of a thermotolerant sporogenic lactic acid bacterium, Bacillus coagulans strain 36D1

    Science.gov (United States)

    Rhee, Mun Su; Moritz, Brélan E.; Xie, Gary; Glavina del Rio, T.; Dalin, E.; Tice, H.; Bruce, D.; Goodwin, L.; Chertkov, O.; Brettin, T.; Han, C.; Detter, C.; Pitluck, S.; Land, Miriam L.; Patel, Milind; Ou, Mark; Harbrucker, Roberta; Ingram, Lonnie O.; Shanmugam, K. T.

    2011-01-01

    Bacillus coagulans is a ubiquitous soil bacterium that grows at 50-55 °C and pH 5.0 and ferments various sugars that constitute plant biomass to L (+)-lactic acid. The ability of this sporogenic lactic acid bacterium to grow at 50-55 °C and pH 5.0 makes this organism an attractive microbial biocatalyst for production of optically pure lactic acid at industrial scale not only from glucose derived from cellulose but also from xylose, a major constituent of hemicellulose. This bacterium is also considered as a potential probiotic. Complete genome sequence of a representative strain, B. coagulans strain 36D1, is presented and discussed. PMID:22675583

  11. Studies on the pathogenic bacterium of ulcer disease in Epinephelus awoara

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Studies were conducted to determine the cause of the acute mortality of cage-cultured Epinephelus awoara in the Tong'an Bay of Xiamen, China during the summer of 2002. Predominant bacteria strain TS-628 was isolated from the diseased grouper. The virulence test confirmed that TS-628 was the pathogenic bacterium. Biochemical characteristics of the isolates were determined using the automatic bacterial identification system and standard tube tests. To further confirm the identification, a 1 121 bp 16S rRNA gene sequence of the isolate was amplified by PCR, which had been deposited into Genbank (accession number: AY747308). According to the biochemical characteristics and by comparing the 16S rRNA gene homology of the isolate, the pathogenic bacterium was identified as Vibrio harveyi. Drug sensitivity tests showed that this pathogenic bacterium was sensitive to 16 antibacterials, especially to chloramphenicol and actinospectacin, but completely resistant to antibacterials likes vancomycin, penicillin, lincomycin, and so on.

  12. Halomonas maura is a physiologically versatile bacterium of both ecological and biotechnological interest.

    Science.gov (United States)

    Llamas, Inmaculada; del Moral, Ana; Martínez-Checa, Fernando; Arco, Yolanda; Arias, Soledad; Quesada, Emilia

    2006-01-01

    Halomonas maura is a bacterium of great metabolic versatility. We summarise in this work some of the properties that make it a very interesting microorganism both from an ecological and biotechnological point of view. It plays an active role in the nitrogen cycle, is capable of anaerobic respiration in the presence of nitrate and has recently been identified as a diazotrophic bacterium. Of equal interest is mauran, the exopolysaccharide produced by H. maura, which contributes to the formation of biofilms and thus affords the bacterium advantages in the colonisation of its saline niches. Mauran is highly viscous, shows thixotropic and pseudoplastic behaviour, has the capacity to capture heavy metals and exerts a certain immunomodulator effect in medicine. All these attributes have prompted us to make further investigations into its molecular characteristics. To date we have described 15 open reading frames (ORF's) related to exopolysaccharide production, nitrogen fixation and nitrate reductase activity among others.

  13. A review of zinc oxide mineral beneficiation using flotation method.

    Science.gov (United States)

    Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

    2014-04-01

    In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Beneficial role of conflict in radioactive waste management programs

    International Nuclear Information System (INIS)

    Payne, B.A.; Williams, R.G.

    1985-01-01

    Of the technical, political, and social problems associated with radioactive waste management, least is known about the latter two. Lay persons tend to generalize negative attitudes about other nuclear activity to radioactive waste management. Thus, conflict appears inevitable between the general public, citizen action groups, and decision-makers on radioactive waste management. The basis of conflict, we believe, can be found in the value orientation of certain groups and in differing perceptions of risk. Research on similar controversial issues reveals that conflict may be beneficial in the long run by contributing to the public's participation level and understanding of the issues, and to the decision-makers' appreciation of the lay perspective. The paper is in three parts. First, we review the sources of conflict over radioactive waste management issues. The negative attitudes and fears of the public toward different types of projects involving radioactivity, value conflicts, and differential perceptions of risk are cited as sources. Next we discuss the consequences of conflict in terms of sociological theory. Finally, we discuss how conflict can be directed and managed to produce an informed decision-making process. When the public is sensitized to an issue, when prevailing attitudes on the issue are negative, and when perceived risks are high - all of which are characteristic of waste management issues - specific steps should be taken to establish a legitimate process of communication and interaction between the public and the sponsor agency. When conflict is recognized as inevitable, the goal of a communications program is no longer to avoid it. It is to use the increased awareness to increase knowledge about waste management issues and public participation in decisions so that the final solution is acceptable at some level to all parties

  15. Helicobacter pylori eradication in complicated peptic ulcer: Beneficial in most?

    Directory of Open Access Journals (Sweden)

    Subair Mohsina

    2016-01-01

    Full Text Available Helicobacter pylori eradication therapy has a role in minimizing the complications of peptic ulcer disease, namely, bleeding, perforation, and obstruction. However, the precise role of H. pylori eradication therapy in the complicated ulcers remains inconclusive, especially in perforation and gastric outlet obstruction. The prevalence of H. pylori in peptic ulcer bleeding patients has been widely underestimated owing to the differences in diagnostic tests and patient characteristics, and hence, it is recommended that an initial negative test should be followed up by a delayed repeat testing to rule out false negativity. It is well established now that eradication of H. pylori in patients with bleeding ulcers reduces rebleeding and ulcer recurrence. Multiple studies have attributed high recurrence rates of duodenal ulcer following simple closure to a high prevalence of H. pylori infection. Eradication therapy decreases the recurrence rate of perforated ulcers, thus justifying the role of H. pylori eradication therapy following the primary surgical management of perforated ulcers. The role of H. pylori in duodenal ulcer with gastric outlet obstruction is yet to be evaluated clearly. There are some reports of resolution of gastric outlet obstruction following therapy for H. pylori, obviating the need for surgery. Clarithromycin-containing regimens are recommended as first-line in areas of low resistance, whereas bismuth-containing quadruple therapy is the first-line empirical treatment in areas of high clarithromycin resistance. Treatment of H. pylori is beneficial in most of the patients with complicated peptic ulcer disease, especially in reducing recurrence of ulcer with or without complications.

  16. Music is Beneficial for Awake Craniotomy Patients: A Qualitative Study.

    Science.gov (United States)

    Jadavji-Mithani, Radhika; Venkatraghavan, Lashmi; Bernstein, Mark

    2015-01-01

    Patients undergoing awake craniotomy may experience high levels of stress. Minimizing anxiety benefits patients and surgeons. Music has many therapeutic effects in altering human mood and emotion. Tonality of music as conveyed by composition in major or minor keys can have an impact on patients' emotions and thoughts. Assessing the effects of listening to major and minor key musical pieces on patients undergoing awake craniotiomy could help in the design of interventions to alleviate anxiety, stress and tension. Twenty-nine patients who were undergoing awake craniotomy were recruited and randomly assigned into two groups: Group 1 subjects listened to major key music and Group 2 listened to minor key compositions. Subjects completed a demographics questionnaire, a pre- and post-operative Beck Anxiety Inventory (BAI) and a semi-structured open-ended interview. RESULTS were analyzed using modified thematic analysis through open and axial coding. Overall, patients enjoyed the music regardless of the key distinctions and stated they benefitted from listening to the music. No adverse reactions to the music were found. Subjects remarked that the music made them feel more at ease and less anxious before, during and after their procedure. Patients preferred either major key or minor key music but not a combination of both. Those who preferred major key pieces said it was on the basis of tonality while the individuals who selected minor key pieces stated that tempo of the music was the primary factor. Overall, listening to music selections was beneficial for the patients. Future work should further investigate the effects of audio interventions in awake surgery through narrative means.

  17. The role of ecological infrastructure on beneficial arthropods in vineyards

    Energy Technology Data Exchange (ETDEWEB)

    Franin, K.; Barić, B.; Kuštera, G.

    2016-11-01

    Weeds and non-cultivated plants have a great impact on abundance and diversity of beneficial arthropods in agriculture. The main aim of this work was to study the influence of the ecological infrastructure (meadows and weedy margins) on the arthropod composition in vineyard surrounding landscape. Research was carried out from May to October during three years. Sampling took place in the ecological infrastructure of three differently managed vineyards (organic, integrated and extensive). Three zones were chosen in each vineyard (3 m, 10 m, and 30 m from the edge of the vineyard). Samples were taken using a standardised sweep net method. In total, we captured 6032 spiders and 1309 insects belonging to 4 orders and 10 families. Arthropod fauna was numerically dominated by Aranea (82.1%); among insects, Coleoptera was the most abundant taxonomic group (10.6%); Neuroptera showed the lowest value (0.88%). Significant differences were found between sites and zones. Organic vineyard showed the highest abundance of arthropods (92.41% were spiders) and in the integrated vineyard there was a 23% of insects. Both the highest abundance of arthropods and the highest Shannon Index value (2.46) was found 3 m away from the edge of the vineyard. Results showed that spiders were the dominant arthropods and ladybugs the dominant insects. Weedy strips near the edge of the vineyard contained a high number of insects and spiders. Our results support the importance of weedy margins in enhancing the population of arthropods as well as in biodiversity promotion. Well-managed field margins could play important role in biological control of vineyard pests. (Author)

  18. The role of ecological infrastructure on beneficial arthropods in vineyards

    Directory of Open Access Journals (Sweden)

    Gabrijela Kuštera

    2016-03-01

    Full Text Available Weeds and non-cultivated plants have a great impact on abundance and diversity of beneficial arthropods in agriculture. The main aim of this work was to study the influence of the ecological infrastructure (meadows and weedy margins on the arthropod composition in vineyard surrounding landscape. Research was carried out from May to October during three years. Sampling took place in the ecological infrastructure of three differently managed vineyards (organic, integrated and extensive. Three zones were chosen in each vineyard (3 m, 10 m, and 30 m from the edge of the vineyard. Samples were taken using a standardised sweep net method. In total, we captured 6032 spiders and 1309 insects belonging to 4 orders and 10 families. Arthropod fauna was numerically dominated by Aranea (82.1%; among insects, Coleoptera was the most abundant taxonomic group (10.6%; Neuroptera showed the lowest value (0.88%. Significant differences were found between sites and zones. Organic vineyard showed the highest abundance of arthropods (92.41% were spiders and in the integrated vineyard there was a 23% of insects. Both the highest abundance of arthropods and the highest Shannon Index value (2.46 was found 3 m away from the edge of the vineyard. Results showed that spiders were the dominant arthropods and ladybugs the dominant insects. Weedy strips near the edge of the vineyard contained a high number of insects and spiders. Our results support the importance of weedy margins in enhancing the population of arthropods as well as in biodiversity promotion. Well-managed field margins could play important role in biological control of vineyard pests.

  19. Toxicity of fruit fly baits to beneficial insects in citrus

    Directory of Open Access Journals (Sweden)

    J.P. Michaud

    2003-03-01

    Full Text Available Two fruit fly baits, Nu-Lure®/malathion and GF-120 (Spinosad® were evaluated in the laboratory for non-target impacts on beneficial insects. Nu-Lure/malathion proved attractive and toxic to adults and larvae of the coccinellid species, Curinus coeruleus Mulsant, Cycloneda sanguinea L. and Harmonia axyridis Pallas, a lacewing species, Chrysoperla rufilabris Burmeister. The coccinellids Olla v-nigrum Mulsant, Scymnus sp. and nymphs of the insidious flower bug, Orius insidiosus (Say did not succumb to Nu-Lure baits, even in no-choice situations. Nu-Lure was also attractive and lethal to adults of two aphidophagous flies; Leucopis sp. and the syrphid fly Pseudodorus clavatus (F.. Both Nu-Lure and GF-120 caused significant mortality to the parasitoid wasps, Aphytis melinus De Bach and Lysiphlebus testaceipes Cresson, within 24 h of exposure. However, GF-120 caused no significant mortality to any coccinellid in either choice or no-choice situations, despite considerable consumption of baits. Adults of P. clavatus tended to avoid GF-120, although mortality was significant in no-choice tests. Although larvae and adults of the lacewing C. rufilabris consumed GF-120, mortality was delayed; adults died 48 -96 h post-exposure and those exposed as larvae died two weeks later in the pupal stage. The Nu-Lure bait did not appear palatable to any of the insects, but the high concentration of malathion (195,000 ppm caused rapid mortality to susceptible insects. Nu-Lure bait without malathion also caused significant mortality to flies and lacewings in cage trials. Although GF-120 bait appeared more benign overall, further research efforts are warranted to increase its selectivity for target fly species and reduce its attractiveness to parasitoids and lacewings. I conclude that the Florida "fly free zone" protocol in its current form is not compatible with an IPM approach to commercial citrus production.

  20. 3-Tesla MRI: Beneficial visualization of the meniscofemoral ligaments?

    Science.gov (United States)

    Ebrecht, Johanna; Krasny, Andrej; Hartmann, Dinah Maria; Rückbeil, Marcia Viviane; Ritz, Thomas; Prescher, Andreas

    2017-10-01

    Recent investigations have confirmed an important stabilizing and protective function of the meniscofemoral ligaments (MFLs) to the knee joint and suggest a clinical relevance. Concerning their incidences, however, there have been discrepancies between data acquired from cadaveric studies and MRI data using 0.3- to 1.5-Tesla field strengths probably due to lower resolution. This study aims to investigate whether imaging with 3-Tesla magnetic resonance imaging (3-T MRI) is beneficial in gaining information regarding the ligaments' incidence, length, width and anatomic variation. 3-T MRI images of 448 patients (224 males, 224 females, with, respectively, 32 patients of each sex in the age groups: 0-20, 21-30, 31-40, 41-50, 51-60, 61-70, >70years) were retrospectively reviewed. The influence of the parameters 'sex' and 'age' was determined. Whereas 71% of the patients had at least one MFL, 22% had an anterior MFL (aMFL), 53% had a posterior MFL (pMFL) and five percent had coexisting ligaments. The pMFLs were more likely to be present in female patients (P<0.05) but if so, they were longer in the males (P<0.05). The pMFL was categorized according to its insertion on the medial femoral condyle. 3-T MRI enables an excellent illustration of the anatomic variations of pMFLs. By modifying an anatomic classification for radiological use we measured lengths and widths of the MFLs without any difficulties. Despite its increased resolution, 3-T MRI lends no diagnostic benefit in visualizing the course of the aMFL or filigree coexisting ligaments as compared to MRI at lower field strengths. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Description of a bacterium associated with redmouth disease of rainbow trout (Salmo gairdneri)

    Science.gov (United States)

    Ross, A.J.; Rucker, R.R.; Ewing, W.H.

    1966-01-01

    A description was given of a gram-negative, peritrichously flagellated, fermentative bacterium that was isolated on numerous occasions from kidney tissues of rainbow trout (Salmo gairdneri) afflicted with redmouth disease. Although the bacteria apparently were members of the family Enterobacteriaceae, it was impossible to determine their taxonomic position within the family with certainty. Hence it was recommended that their taxonomic position remain sub judice for the present. As a temporary designation RM bacterium was used. Redmouth disease was transmitted from infected to normal fish through the medium of water.

  2. From Genome to Function: Systematic Analysis of the Soil Bacterium Bacillus Subtilis

    Science.gov (United States)

    Crawshaw, Samuel G.; Wipat, Anil

    2001-01-01

    Bacillus subtilis is a sporulating Gram-positive bacterium that lives primarily in the soil and associated water sources. Whilst this bacterium has been studied extensively in the laboratory, relatively few studies have been undertaken to study its activity in natural environments. The publication of the B. subtilis genome sequence and subsequent systematic functional analysis programme have provided an opportunity to develop tools for analysing the role and expression of Bacillus genes in situ. In this paper we discuss analytical approaches that are being developed to relate genes to function in environments such as the rhizosphere. PMID:18628943

  3. Influence of commercial inactivated yeast derivatives on the survival of probiotic bacterium Lactobacillus rhamnosus HN001 in an acidic environment.

    Science.gov (United States)

    Toh, Mingzhan; Liu, Shao Quan

    2017-12-01

    This study evaluated the influence of three inactivated yeast derivatives (IYDs) used in wine production, namely OptiRed ® , OptiWhite ® and Noblesse ® , on the viability of the probiotic strain Lactobacillus rhamnosus HN001 in an acidic environment. Addition of the IYDs at 3 g/L significantly enhanced the survival of the probiotic bacteria by 2.75-4.05 log cycles after 10-h exposure in a pH 3.0 buffer. Acid stress assay with IYD components obtained after centrifugation and filtration revealed that water-soluble compounds were responsible for improving the acid tolerance of L. rhamnosus HN001 for all three preparations. Differences in protective effect amongst the IYDs on L. rhamnosus HN001 were observed when permeates and retentates of the water-soluble extracts, obtained through ultrafiltration with a 2 kDa membrane, were assayed against the lactic acid bacterium. Chemical analysis of the water-soluble components suggests that low molecular weight polysaccharides, specific free amino acids and/or antioxidants in the 2 kDa permeates could have contributed to the enhanced survival of L. rhamnosus HN001 during acid stress. The contrast amongst the 2 kDa retentates' viability enhancing property may have been attributed to the differences in size and structure of the higher molecular weight carbohydrates and proteins, as the survival of the probiotic did not relate to the concentration of these compounds. These results suggests that oenological IYDs could potentially be applied to probiotic foods for enhancing the acid tolerance of the beneficial microorganisms, and consequently prolonging the shelf life of these products.

  4. Genome Sequence of Lactobacillus delbrueckii subsp. lactis CNRZ327, a Dairy Bacterium with Anti-Inflammatory Properties.

    Science.gov (United States)

    El Kafsi, Hela; Binesse, Johan; Loux, Valentin; Buratti, Julien; Boudebbouze, Samira; Dervyn, Rozenn; Hammani, Amal; Maguin, Emmanuelle; van de Guchte, Maarten

    2014-07-17

    Lactobacillus delbrueckii subsp. lactis CNRZ327 is a dairy bacterium with anti-inflammatory properties both in vitro and in vivo. Here, we report the genome sequence of this bacterium, which appears to contain no less than 215 insertion sequence (IS) elements, an exceptionally high number regarding the small genome size of the strain. Copyright © 2014 El Kafsi et al.

  5. Intestinimonas butyriciproducens gen. nov., sp. nov., a novel butyrate-producing bacterium from the mouse intestine

    NARCIS (Netherlands)

    Kläring, K.; Hanske, L.; Bui, T.P.N.; Charrier, C.; Blaut, M.; Haller, D.; Plugge, C.M.; Clavel, T.

    2013-01-01

    Whilst creating a bacterial collection of strains from the mouse intestine, we isolated a Gram-negative, spore-forming, non-motile and strictly anaerobic rod-shaped bacterium from the caecal content of a TNFdeltaARE mouse. The isolate, referred to as strain SRB-521-5-IT, was originally cultured on a

  6. Draft Genome Sequence of Desulfuromonas acetexigens Strain 2873, a Novel Anode-Respiring Bacterium

    KAUST Repository

    Katuri, Krishna

    2017-03-03

    Here, we report the draft genome sequence of Desulfuromonas acetexigens strain 2873, which was originally isolated from digester sludge from a sewage treatment plant in Germany. This bacterium is capable of anode respiration with high electrochemical activity in microbial electrochemical systems. The draft genome contains 3,376 predicted protein-coding genes and putative multiheme c-type cytochromes.

  7. Design of semi industrial radium separator by a new bacterium MGF-48

    International Nuclear Information System (INIS)

    Ghafourian, H.; Emami, M.R.; Farazmand, A.

    1998-01-01

    Following of a research work which has been recently published in AEOI scientific Bulletin no. 14, a semi industrial bioreactor has been designed for separation of radium using a new bacterium MGF-48. This bioreactor could be utilized for a high rate separation of radium in semi industrial scale. (author)

  8. Complete genome sequence of the bioleaching bacterium Leptospirillum sp. group II strain CF-1.

    Science.gov (United States)

    Ferrer, Alonso; Bunk, Boyke; Spröer, Cathrin; Biedendieck, Rebekka; Valdés, Natalia; Jahn, Martina; Jahn, Dieter; Orellana, Omar; Levicán, Gloria

    2016-03-20

    We describe the complete genome sequence of Leptospirillum sp. group II strain CF-1, an acidophilic bioleaching bacterium isolated from an acid mine drainage (AMD). This work provides data to gain insights about adaptive response of Leptospirillum spp. to the extreme conditions of bioleaching environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Thermaerobacter litoralis sp. nov., a strictly aerobic and thermophilic bacterium isolated from a coastal hydrothermal field

    DEFF Research Database (Denmark)

    Tanaka, Reiji; Kawaichi, Satoshi; Nishimura, Hiroshi

    2006-01-01

    A novel thermophilic bacterium, strain KW1T, was isolated from a coastal hydrothermal field on the Satsuma Peninsula, Kagoshima Prefecture, Japan. The variably Gram-stained cells were motile rods with flagella, did not form spores and proliferated at 52-78°C (optimum, 70°C), pH 5-8 (optimum, pH 7...

  10. Flavobacterium nitratireducens sp. nov., an amylolytic bacterium of the family Flavobacteriaceae isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Nupur; Bhumika, V.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-negative, rod-shaped, non-motile bacterium, designated strain N1 sup(T), was isolated from a marine water sample collected from the sea shore, Bay of Bengal, Visakhapatnam, India. The strain was positive for starch hydrolysis, nitrate...

  11. Marinobacter nitratireducens sp. nov., a halophilic and lipolytic bacterium isolated from coastal surface sea water

    Digital Repository Service at National Institute of Oceanography (India)

    Bhumika, V.; Ravinder, K.; Korpole, S.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-stain-negative, rod-shaped, motile bacterium, designated strain AK21T , was isolated from coastal surface sea water at Visakhapatnam, India. The strain was positive for oxidase, catalase, lipase, L-proline arylamidase...

  12. Aliidiomarina haloalkalitolerans sp. nov., a marine bacterium isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; Nupur; AnilKumar, P.

    A novel Gram-negative, rod shaped, motile, non-sporing strictly aerobic bacterium, designated strain AK5 sup(T), was isolated from a sea water sample collected near Visakhapatnam coast, Bay of Bengal, India. Colonies on marine agar were circular, 3...

  13. Draft Genome Sequence of Advenella kashmirensis Strain W13003, a Polycyclic Aromatic Hydrocarbon-Degrading Bacterium

    Science.gov (United States)

    Jin, Decai; Zhou, Lisha; Wu, Liang; An, Wei; Zhao, Lin

    2014-01-01

    Advenella kashmirensis strain W13003 is a polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from PAH-contaminated marine sediments. Here, we report the 4.8-Mb draft genome sequence of this strain, which will provide insights into the diversity of A. kashmirensis and the mechanism of PAH degradation in the marine environment. PMID:24482505

  14. Draft Genome Sequence of Desulfuromonas acetexigens Strain 2873, a Novel Anode-Respiring Bacterium

    KAUST Repository

    Katuri, Krishna; Albertsen, Mads; Saikaly, Pascal

    2017-01-01

    Here, we report the draft genome sequence of Desulfuromonas acetexigens strain 2873, which was originally isolated from digester sludge from a sewage treatment plant in Germany. This bacterium is capable of anode respiration with high electrochemical activity in microbial electrochemical systems. The draft genome contains 3,376 predicted protein-coding genes and putative multiheme c-type cytochromes.

  15. Draft Genome Sequence of Lactobacillus paracasei DmW181, a Bacterium Isolated from Wild Drosophila

    OpenAIRE

    Hammer, Austin J.; Walters, Amber; Carroll, Courtney; Newell, Peter D.; Chaston, John M.

    2017-01-01

    ABSTRACT The draft genome sequence of Lactobacillus paracasei DmW181, an anaerobic bacterium isolate from wild Drosophila flies, is reported here. Strain DmW181 possesses genes for sialic acid and mannose metabolism. The assembled genome is 3,201,429?bp, with 3,454 predicted genes.

  16. Draft Genome Sequence of Lactobacillus paracasei DmW181, a Bacterium Isolated from Wild Drosophila.

    Science.gov (United States)

    Hammer, Austin J; Walters, Amber; Carroll, Courtney; Newell, Peter D; Chaston, John M

    2017-07-06

    The draft genome sequence of Lactobacillus paracasei DmW181, an anaerobic bacterium isolate from wild Drosophila flies, is reported here. Strain DmW181 possesses genes for sialic acid and mannose metabolism. The assembled genome is 3,201,429 bp, with 3,454 predicted genes. Copyright © 2017 Hammer et al.

  17. Whole-Genome Sequence of the Purple Photosynthetic Bacterium Rhodovulum sulfidophilum Strain W4

    OpenAIRE

    Masuda, Shinji; Hori, Koichi; Maruyama, Fumito; Ren, Shukun; Sugimoto, Saori; Yamamoto, Nozomi; Mori, Hiroshi; Yamada, Takuji; Sato, Shusei; Tabata, Satoshi; Ohta, Hiroyuki; Kurokawa, Ken

    2013-01-01

    We report the draft genome sequence of the purple photosynthetic bacterium Rhodovulum sulfidophilum. The photosynthesis gene cluster comprises two segments?a unique feature among photosynthesis gene clusters of purple bacteria. The genome information will be useful for further analysis of bacterial photosynthesis.

  18. 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

  19. Draft Genome Sequence of Pontibacter sp. nov. BAB1700, a Halotolerant, Industrially Important Bacterium

    Science.gov (United States)

    Joshi, M. N.; Sharma, A. C.; Pandya, R. V.; Patel, R. P.; Saiyed, Z. M.; Saxena, A. K.

    2012-01-01

    Pontibacter sp. nov. BAB1700 is a halotolerant, Gram-negative, rod-shaped, pink-pigmented, menaquinone-7-producing bacterium isolated from sediments of a drilling well. The draft genome sequence of the strain, consisting of one chromosome of 4.5 Mb, revealed vital gene clusters involved in vitamin biosynthesis and resistance against various metals and antibiotics. PMID:23105068

  20. The 2015 Nobel Prize in Physiology or Medicine: A Soil Bacterium ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 4. The 2015 Nobel Prize in Physiology or Medicine: A Soil Bacterium and a Chinese Herb Steal the Show. Pundi N Rangarajan. General Article Volume 21 Issue 4 April 2016 pp 315-326 ...

  1. Isolation and Structure Elucidation of a Novel Yellow Pigment from the Marine Bacterium Pseudoalteromonas tunicata

    Directory of Open Access Journals (Sweden)

    N. Kumar

    2005-10-01

    Full Text Available The marine environment is a major source for many novel natural compounds. A new yellow pigment has been isolated from the marine bacterium P. tunicata and identified as a new member of the tambjamine class of compounds. The structural identification was achieved by a combination of 1D and 2D-NMR spectroscopy and high resolution mass spectrometry data.

  2. Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

    Science.gov (United States)

    A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

  3. Oceanospirillum nioense sp. nov., a marine bacterium isolated from sediment sample of Palk bay, India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.K.; Bhumika, V.; Thomas, M.; AnilKumar, P.; Srinivas, T.N.R.

    A novel Gram-negative, spiral shaped, motile bacterium, designated strain NIO-S6T, was isolated from a sediment sample collected from Offshore Rameswaram, Tamilnadu, India. Strain NIO-S6 sup(T) was found to be positive for oxidase, DNase and lysine...

  4. 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)

  5. Removal of zinc from aqueous solution by metal resistant symbiotic bacterium Mesorhizobium amorphae

    DEFF Research Database (Denmark)

    Hao, Xiuli; Mohamad, Osama Abdalla; Xie, Pin

    2014-01-01

    Biosorption of zinc by living biomasses of metal resistant symbiotic bacterium Mesorhizobium amorphae CCNWGS0123 was investigated under optimal conditions at pH 5.0, initial metal concentrations of 100 mg L-1, and a dose of 1.0 g L-1. M. amorphae exhibited an efficient removal of Zn2+ from aqueous...

  6. Two-dimensional gel-based alkaline proteome of the probiotic bacterium Lactobacillus acidophilus NCFM

    DEFF Research Database (Denmark)

    Majumder, Avishek; Cai, Liyang; Ejby, Morten

    2012-01-01

    Lactobacillus acidophilus NCFM (NCFM) is a well‐documented probiotic bacterium isolated from human gut. Detailed 2D gel‐based NCFM proteomics addressed the so‐called alkaline range, i.e., pH 6–11. Proteins were identified in 150 of the 202 spots picked from the Coomassie Brilliant Blue stained 2D...

  7. Pantoea agglomerans: a marvelous bacterium of evil and good.Part I. Deleterious effects: Dust-borne endotoxins and allergens - focus on cotton dust.

    Science.gov (United States)

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Milanowski, Janusz

    2015-01-01

    The ubiquitous Gram-negative bacterium Pantoea agglomerans (synonyms: Enterobacter agglomerans, Erwinia herbicola) is known both as an epiphytic microbe developing on the surface of plants and as an endophytic organism living inside the plants. The bacterium occurs also abundantly in plant and animal products, in the body of arthropods and other animals, in water, soil, dust and air, and occasionally in humans. From the human viewpoint, the role of this organism is ambiguous, both deleterious and beneficial: on one side it causes disorders in people exposed to inhalation of organic dusts and diseases of crops, and on the other side it produces substances effective in the treatment of cancer and other diseases of humans and animals, suppresses the development of various plant pathogens, promotes plant growth, and appears as a potentially efficient biofertilizer and bioremediator. P. agglomerans was identified as a predominant bacterium on cotton plant grown all over the world, usually as an epiphyte, rarely as pathogen. It is particularly numerous on cotton bract after senescence. During processing of cotton in mills, bacteria and their products are released with cotton dust into air and are inhaled by workers, causing respiratory and general disorders, usually defined as byssinosis. The most adverse substance is endotoxin, a heteropolymer macromolecule present in the outermost part of the cell wall, consisting of lipopolysaccharide (LPS) as a major constituent, phospholipids and protein. The numerous experiments carried out in last quarter of XXth century on laboratory animals and human volunteers supported a convincing evidence that the inhaled endotoxin produced by P. agglomerans causes numerous pathologic effects similar to those elicited by cotton dust, such as influx of free lung cells into airways and activation of alveolar macrophages which secrete mediators (prostaglandins, platelet-activating factor, interleukin-1, tumor necrosis factor) that cause

  8. Pantoea agglomerans: a marvelous bacterium of evil and good.Part I. Deleterious effects: Dust-borne endotoxins and allergens – focus on cotton dust

    Directory of Open Access Journals (Sweden)

    Jacek Dutkiewicz

    2015-12-01

    Full Text Available The ubiquitous Gram-negative bacterium Pantoea agglomerans (synonyms: Enterobacter agglomerans, Erwinia herbicola is known both as an epiphytic microbe developing on the surface of plants and as an endophytic organism living inside the plants. The bacterium occurs also abundantly in plant and animal products, in the body of arthropods and other animals, in water, soil, dust and air, and occasionally in humans. From the human viewpoint, the role of this organism is ambiguous, both deleterious and beneficial: on one side it causes disorders in people exposed to inhalation of organic dusts and diseases of crops, and on the other side it produces substances effective in the treatment of cancer and other diseases of humans and animals, suppresses the development of various plant pathogens, promotes plant growth, and appears as a potentially efficient biofertilizer and bioremediator. P. agglomerans was identified as a predominant bacterium on cotton plant grown all over the world, usually as an epiphyte, rarely as pathogen. It is particularly numerous on cotton bract after senescence. During processing of cotton in mills, bacteria and their products are released with cotton dust into air and are inhaled by workers, causing respiratory and general disorders, usually defined as byssinosis. The most adverse substance is endotoxin, a heteropolymer macromolecule present in the outermost part of the cell wall, consisting of lipopolysaccharide (LPS as a major constituent, phospholipids and protein. The numerous experiments carried out in last quarter of XXth century on laboratory animals and human volunteers supported a convincing evidence that the inhaled endotoxin produced by P. agglomerans causes numerous pathologic effects similar to those elicited by cotton dust, such as influx of free lung cells into airways and activation of alveolar macrophages which secrete mediators (prostaglandins, platelet-activating factor, interleukin-1, tumor necrosis factor

  9. Pantoea agglomerans : a marvelous bacterium of evil and good. Part I. Deleterious effects: Dust-borne endotoxins and allergens – focus on cotton dust

    Directory of Open Access Journals (Sweden)

    Jacek Dutkiewicz

    2015-12-01

    Full Text Available The ubiquitous Gram-negative bacterium Pantoea agglomerans (synonyms: Enterobacter agglomerans , Erwinia herbicola is known both as an epiphytic microbe developing on the surface of plants and as an endophytic organism living inside the plants. The bacterium occurs also abundantly in plant and animal products, in the body of arthropods and other animals, in water, soil, dust and air, and occasionally in humans. From the human viewpoint, the role of this organism is ambiguous, both deleterious and beneficial: on one side it causes disorders in people exposed to inhalation of organic dusts and diseases of crops, and on the other side it produces substances effective in the treatment of cancer and other diseases of humans and animals, suppresses the development of various plant pathogens, promotes plant growth, and appears as a potentially efficient biofertilizer and bioremediator. P. agglomerans was identified as a predominant bacterium on cotton plant grown all over the world, usually as an epiphyte, rarely as pathogen. It is particularly numerous on cotton bract after senescence. During processing of cotton in mills, bacteria and their products are released with cotton dust into air and are inhaled by workers, causing respiratory and general disorders, usually defined as byssinosis. The most adverse substance is endotoxin, a heteropolymer macromolecule present in the outermost part of the cell wall, consisting of lipopolysaccharide (LPS as a major constituent, phospholipids and protein. The numerous experiments carried out in last quarter of XXth century on laboratory animals and human volunteers supported a convincing evidence that the inhaled endotoxin produced by P. agglomerans causes numerous pathologic effects similar to those elicited by cotton dust, such as influx of free lung cells into airways and activation of alveolar macrophages which secrete mediators (prostaglandins, platelet-activating factor, interleukin-1, tumor necrosis factor

  10. New recombinant bacterium comprises a heterologous gene encoding glycerol dehydrogenase and/or an up-regulated native gene encoding glycerol dehydrogenase, useful for producing ethanol

    DEFF Research Database (Denmark)

    2010-01-01

    dehydrogenase encoding region of the bacterium, or is inserted into a phosphotransacetylase encoding region of the bacterium, or is inserted into an acetate kinase encoding region of the bacterium. It is operably linked to an inducible, a regulated or a constitutive promoter. The up-regulated glycerol......TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation (claimed): Producing recombinant bacterium having enhanced ethanol production characteristics when cultivated in growth medium comprising glycerol comprises: (a) transforming a parental bacterium by (i) the insertion of a heterologous gene encoding...... glycerol dehydrogenase; and/or (ii) up-regulating a native gene encoding glycerol dehydrogenase; and (b) obtaining the recombinant bacterium. Preferred Bacterium: In the recombinant bacterium above, the inserted heterologous gene and/or the up-regulated native gene is encoding a glycerol dehydrogenase...

  11. Purposes of double taxation treaties and interpretation of beneficial owner concept in Ukraine

    OpenAIRE

    Pavlo Selezen

    2017-01-01

    The term ‟beneficial owner” has been interpreted by Ukrainian courts concerning the application of double taxation treaties’ provisions since the adoption of the Tax Code of Ukraine in 2010. Changing nature of the beneficial owner concept, its importance as an instrument for treaty shopping counteraction and the necessity of its proper interpretation in the Ukrainian reality are the main factors that have a strong impact on the development of court practice concerning beneficial ownership....

  12. Enrichment and physiological characterization of an anaerobic ammonium-oxidizing bacterium ‘ Candidatus Brocadia sapporoensis’

    KAUST Repository

    Narita, Yuko; Zhang, Lei; Kimura, Zen-ichiro; Ali, Muhammad; Fujii, Takao; Okabe, Satoshi

    2017-01-01

    Anaerobic ammonium-oxidation (anammox) is recognized as an important microbial process in the global nitrogen cycle and wastewater treatment. In this study, we successfully enriched a novel anammox bacterium affiliated with the genus ‘Candidatus Brocadia’ with high purity (>90%) in a membrane bioreactor (MBR). The enriched bacterium was distantly related to the hitherto characterized ‘Ca. Brocadia fulgida’ and ‘Ca. Brocadia sinica’ with 96% and 93% of 16S ribosomal RNA gene sequence identity, respectively. The bacterium exhibited the common structural features of anammox bacteria and the production of hydrazine in the presence of hydroxylamine under anoxic conditions. The temperature range of anammox activity was 20 − 45°C with a maximum activity at 37°C. The maximum specific growth rate (μmax) was determined to be 0.0082h−1 at 37°C, corresponding to a doubling time of 3.5 days. The half-saturation constant (KS) for nitrite was 5±2.5μM. The anammox activity was inhibited by nitrite with 11.6mM representing the 50% inhibitory concentration (IC50) but no significant inhibition was observed in the presence of formate and acetate. The major respiratory quinone was identified to be menaquinone-7 (MK-7). Comparative genome analysis revealed that the anammox bacterium enriched in present study shared nearly half of genes with ‘Ca. Brocadia sinica’ and ‘Ca. Brocadia fulgida’. The bacterium enriched in this study showed all known physiological characteristics of anammox bacteria and can be distinguished from the close relatives by its rRNA gene sequences. Therefore, we proposed the name ‘Ca. Brocadia sapporoensis’ sp. nov.

  13. Isolation, identification, and biocontrol of antagonistic bacterium against Botrytis cinerea after tomato harvest

    Directory of Open Access Journals (Sweden)

    Jun-Feng Shi

    Full Text Available ABSTRACT Tomato is one of the most important vegetables in the world. Decay after harvest is a major issue in the development of tomato industry. Currently, the most effective method for controlling decay after harvest is storage of tomato at low temperature combined with usage of chemical bactericide; however, long-term usage of chemical bactericide not only causes pathogen resistance but also is harmful for human health and environment. Biocontrol method for the management of disease after tomato harvest has great practical significance. In this study, antagonistic bacterium B-6-1 strain was isolated from the surface of tomato and identified as Enterobacter cowanii based on morphological characteristics and physiological and biochemical features combined with sequence analysis of 16SrDNA and ropB gene and construction of dendrogram. Effects of different concentrations of antagonistic bacterium E. cowanii suspension on antifungal activity after tomato harvest were analyzed by mycelium growth rate method. Results revealed that antifungal activity was also enhanced with increasing concentrations of antagonistic bacterium; inhibitory rates of 1 × 105 colony-forming units (cfu/mL antagonistic bacterial solution on Fusarium verticillioides, Alternaria tenuissima, and Botrytis cinerea were 46.31%, 67.48%, and 75.67%, respectively. By using in vivo inoculation method, it was further confirmed that antagonistic bacterium could effectively inhibit the occurrence of B. cinerae after tomato harvest, biocontrol effect of 1 × 109 cfu/mL zymotic fluid reached up to 95.24%, and antagonistic bacterium E. cowanii has biocontrol potential against B. cinerea after harvest of fruits and vegetables.

  14. Enrichment and physiological characterization of an anaerobic ammonium-oxidizing bacterium ‘ Candidatus Brocadia sapporoensis’

    KAUST Repository

    Narita, Yuko

    2017-08-18

    Anaerobic ammonium-oxidation (anammox) is recognized as an important microbial process in the global nitrogen cycle and wastewater treatment. In this study, we successfully enriched a novel anammox bacterium affiliated with the genus ‘Candidatus Brocadia’ with high purity (>90%) in a membrane bioreactor (MBR). The enriched bacterium was distantly related to the hitherto characterized ‘Ca. Brocadia fulgida’ and ‘Ca. Brocadia sinica’ with 96% and 93% of 16S ribosomal RNA gene sequence identity, respectively. The bacterium exhibited the common structural features of anammox bacteria and the production of hydrazine in the presence of hydroxylamine under anoxic conditions. The temperature range of anammox activity was 20 − 45°C with a maximum activity at 37°C. The maximum specific growth rate (μmax) was determined to be 0.0082h−1 at 37°C, corresponding to a doubling time of 3.5 days. The half-saturation constant (KS) for nitrite was 5±2.5μM. The anammox activity was inhibited by nitrite with 11.6mM representing the 50% inhibitory concentration (IC50) but no significant inhibition was observed in the presence of formate and acetate. The major respiratory quinone was identified to be menaquinone-7 (MK-7). Comparative genome analysis revealed that the anammox bacterium enriched in present study shared nearly half of genes with ‘Ca. Brocadia sinica’ and ‘Ca. Brocadia fulgida’. The bacterium enriched in this study showed all known physiological characteristics of anammox bacteria and can be distinguished from the close relatives by its rRNA gene sequences. Therefore, we proposed the name ‘Ca. Brocadia sapporoensis’ sp. nov.

  15. Draft genome of an Aerophobetes bacterium reveals a facultative lifestyle in deep-sea anaerobic sediments

    KAUST Repository

    Wang, Yong

    2016-07-01

    Aerophobetes (or CD12) is a recently defined bacterial phylum, of which the metabolic processes and ecological importance remain unclear. In the present study, we obtained the draft genome of an Aerophobetes bacterium TCS1 from saline sediment near the Thuwal cold seep in the Red Sea using a genome binning method. Analysis of 16S rRNA genes of TCS1 and close relatives revealed wide distribution of Aerophobetes in deep-sea sediments. Phylogenetic relationships showed affinity between Aerophobetes TCS1 and some thermophilic bacterial phyla. The genome of TCS1 (at least 1.27 Mbp) contains a full set of genes encoding core metabolic pathways, including glycolysis and pyruvate fermentation to produce acetyl-CoA and acetate. The identification of cross-membrane sugar transporter genes further indicates its potential ability to consume carbohydrates preserved in the sediment under the microbial mat. Aerophobetes bacterium TCS1 therefore probably carried out saccharolytic and fermentative metabolism. The genes responsible for autotrophic synthesis of acetyl-CoA via the Wood–Ljungdahl pathway were also found in the genome. Phylogenetic study of the essential genes for the Wood–Ljungdahl pathway implied relative independence of Aerophobetes bacterium from the known acetogens and methanogens. Compared with genomes of acetogenic bacteria, Aerophobetes bacterium TCS1 genome lacks the genes involved in nitrogen metabolism, sulfur metabolism, signal transduction and cell motility. The metabolic activities of TCS1 might depend on geochemical conditions such as supplies of CO2, hydrogen and sugars, and therefore the TCS1 might be a facultative bacterium in anaerobic saline sediments near cold seeps. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg.

  16. INOCULACIÓN AL SUELO CON Pseudomonas fluorescens, Azospirillum oryzae, Bacillus subtilis Y MICROORGANISMOS DE MONTAÑA (MM Y SU EFECTO SOBRE UN SISTEMA DE ROTACIÓN SOYA-TOMATE BAJO CONDICIONES DE INVERNADERO

    Directory of Open Access Journals (Sweden)

    Leida Castro Barquero

    2015-01-01

    Full Text Available Se evaluó un sistema de rotación soya- tomate, con incorporación de biomasa verde y aplicación de inóculos microbianos individuales y en mezcla sobre el crecimiento de las plantas y propiedades edáficas; para ello se evaluaron en invernadero por 24 meses los siguientes 9 trata - mientos: solo tomate (T; rotación tomate-soya (TS; rotación tomate-soya con inoculaciones individuales de Azospirillum oryzae (A; de Pseudomonas fluorescens (P; de Bacillus sub - tilis (B; de microorganismos de montaña (MM; y las inoculaciones en mezcla de B. subtilis y P. fluorescens (BP; de B. subtilis, P. fluorescens y A. oryzae ( BPA; d e B. subtilis , P. fluorescens , Azospirillum sp. y MM (BPAMM. Se evalua - ron las variables físicas: densidad aparente y de partículas; conductividad hidráulica; poros totales; estabilidad de agregados; resistencia a la penetración (RP; las variables químicas: pH; conductividad eléctrica; contenido de N y C; relación C/N; contenido de nutrientes en suelos y foliares; las variables biológicas: respiración de suelos, unidades formadoras de colonias de hongos, bacterias y actinomicetos y el peso fres - co y seco foliar. Las variables físicas no fueron afectadas por los tratamientos, con excepción de RP, que fue mayor en el tratamiento T. Las varia - bles biológicas y químicas fueron sensibles a los tratamientos, con valores significativamente más altos en presencia de MM. Destaca el incremento del P en solución de suelo en tratamientos a los que se adicionó MM: pasó de 6 a 20 mg.l -1 ; esta condición se reflejó además en la cantidad de P en el tejido foliar al final del ensayo. Se determi - nó que el pH, CE y la respiración del suelo fueron afectados por la interacción entre los tratamientos aplicados y el tiempo transcurrido; los mayores valores se obtuvieron al final del ensayo y en los tratamientos con MM.

  17. Inoculación al suelo con Pseudomonas fluorescens, Azospirillum oryzae, Bacillus subtilis y microorganismos de montaña (mm y su efecto sobre un sistema de rotación soya-tomate bajo condiciones de invernadero

    Directory of Open Access Journals (Sweden)

    Leida Castro Barquero

    2015-11-01

    Full Text Available Se evaluó un sistema de rotación soyatomate, con incorporación de biomasa verde y aplicación de inóculos microbianos individuales y en mezcla sobre el crecimiento de las plantas y propiedades edáficas; para ello se evaluaron en invernadero por 24 meses los siguientes 9 tratamientos: solo tomate (T; rotación tomate-soya (TS; rotación tomate-soya con inoculaciones individuales de Azospirillum oryzae (A; de Pseudomonas fluorescens (P; de Bacillus subtilis (B; de microorganismos de montaña (MM; y las inoculaciones en mezcla de B. subtilis y P. fluorescens (BP; de B. subtilis, P. fluorescens y A. oryzae (BPA; de B. subtilis, P. fluorescens, Azospirillum sp. y MM (BPAMM. Se evaluaron las variables físicas: densidad aparente y de partículas; conductividad hidráulica; poros totales; estabilidad de agregados; resistencia a la penetración (RP; las variables químicas: pH; conductividad eléctrica; contenido de N y C; relación C/N; contenido de nutrientes en suelos y foliares; las variables biológicas: respiración de suelos, unidades formadoras de colonias de hongos, bacterias y actinomicetos y el peso fresco y seco foliar. Las variables físicas no fueron afectadas por los tratamientos, con excepción de RP, que fue mayor en el tratamiento T. Las variables biológicas y químicas fueron sensibles a los tratamientos, con valores significativamente más altos en presencia de MM. Destaca el incremento del P en solución de suelo en tratamientos a los que se adicionó MM: pasó de 6 a 20 mg.l-1; esta condición se reflejó además en la cantidad de P en el tejido foliar al final del ensayo. Se determinó que el pH, CE y la respiración del suelo fueron afectados por la interacción entre los tratamientos aplicados y el tiempo transcurrido; los mayores valores se obtuvieron al final del ensayo y en los tratamientos con MM.

  18. Development of a Low Input and sustainable Switchgrass Feedstock Production System Utilizing Beneficial Bacterial Endophytes

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Chuansheng [IALR; Nowak, Jerzy [VPISU; Seiler, John [VPISU

    2014-10-24

    Switchgrass represents a promising feedstock crop for US energy sustainability. However, its broad utilization for bioenergy requires improvements of biomass yields and stress tolerance. In this DOE funded project, we have been working on harnessing beneficial bacterial endophytes to enhance switchgrass performance and to develop a low input feedstock production system for marginal lands that do not compete with the production of food crops. We have demonstrated that one of most promising plant growth-promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize roots and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, greenhouse, as well as field conditions. Furthermore, PsJN bacterization improved growth and development of switchgrass seedlings, significantly stimulated plant root and shoot growth, and tiller number in the field, and enhanced biomass accumulation on both poor (p<0.001) and rich (p<0.05) soils, with more effective stimulation of plant growth in low fertility soil. Plant physiology measurements showed that PsJN inoculated Alamo had consistently lower transpiration, lower stomatal conductance, and higher water use efficiency in greenhouse conditions. These physiological changes may significantly contribute to the recorded growth enhancement. PsJN inoculation rapidly results in an increase in photosynthetic rates which contributes to the advanced growth and development. Some evidence suggests that this initial growth advantage decreases with time when resources are not limited such as in greenhouse studies. Additionally, better drought resistance and drought hardening were observed in PsJN inoculated switchgrass. Using the DOE-funded switchgrass EST microarray, in a collaboration with the Genomics Core Facility at the Noble Foundation, we have determined gene expression profile changes in both responsive switchgrass cv. Alamo and non-responsive cv. Cave-in-Rock (CR) following Ps

  19. 75 FR 11207 - Policy Statement on Obtaining and Retaining Beneficial Ownership Information for Anti-Money...

    Science.gov (United States)

    2010-03-10

    ... Retaining Beneficial Ownership Information for Anti-Money Laundering Purposes AGENCY: Securities and...-money laundering purposes. DATES: Effective Date: March 5, 2010. FOR FURTHER INFORMATION CONTACT... retaining beneficial ownership information for anti-money laundering purposes. This guidance is being issued...

  20. 17 CFR 270.3c-2 - Definition of beneficial ownership in small business investment companies.

    Science.gov (United States)

    2010-04-01

    ... 1940 § 270.3c-2 Definition of beneficial ownership in small business investment companies. For the... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definition of beneficial ownership in small business investment companies. 270.3c-2 Section 270.3c-2 Commodity and Securities...

  1. Beneficial and Detrimental Effects of UV on Aquatic Organisms: Implications of Spectral Variation

    NARCIS (Netherlands)

    Williamson, C.E.; Neale, P.J.; Grad, G.; Lange, de H.J.; Hargreaves, B.R.

    2001-01-01

    Solar ultraviolet radiation (UVR) may have beneficial as well as detrimental effects on living systems. For example, UV-B radiation (280¿320 nm) is generally damaging, while UV-A radiation (320¿400 nm) may cause damage or stimulate beneficial photorepair of UV-B damage. The nature of both direct and

  2. Fitness effects of beneficial mutations: the mutational landscape model in experimental evolution

    DEFF Research Database (Denmark)

    Betancourt, Andrea J.; Bollback, Jonathan Paul

    2006-01-01

    of beneficial mutations should be roughly exponentially distributed. The prediction appears to be borne out by most of these studies, at least qualitatively. Another study showed that a modified version of the model was able to predict, with reasonable accuracy, which of a ranked set of beneficial alleles...

  3. Effect of Azospirillum brasilense on the harvest and radical development of sugar cane plants, variety C86 - 456, obtained by in vitro culture in normal conditions and under overhumidity of soil

    Directory of Open Access Journals (Sweden)

    Sergio Rodríguez Rodríguez

    2005-01-01

    Full Text Available In order to know the influence of the bacteria Azospirillum brasilense on plants of sugar cane, cultivar C86-456, from tissue culture under normal conditions and flooded soil in a Vertisol from El Valle del Cauto, an experiment was carried out using an at random blocks design. The main crop variables (pol in cane, t. caña.ha-1 and t. pol.ha-1 at the twelve months of age were taken, as stump of spring of the year and the development reached by the radical system in its more active area to achieve this experiment. The best results in the crop variables and development of the radical system were obtained it the treatments where the bacteria was present, although non significant under both conditions, evidencing that the stress due to excess of water in the soil affects the normal development of the sugar cane in general by modifying the kindness that the rhizospheric microorganism provides. Key words: biofertilizer, radical system, Saccharum, yield

  4. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium.

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

  5. The atherogenic bacterium Porphyromonas gingivalis evades circulating phagocytes by adhering to erythrocytes

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Holmstrup, Palle; Damgaard, Christian

    2011-01-01

    A relationship between periodontitis and coronary heart disease has been investigated intensively. A pathogenic role for the oral bacterium Porphyromonas gingivalis has been suggested for both diseases. We examined whether complement activation by P. gingivalis strain ATCC 33277 allows...... the bacterium to adhere to human red blood cells (RBCs) and thereby evade attack by circulating phagocytes. On incubation with normal human serum, the P. gingivalis strain efficiently fixed complement component 3 (C3). Incubation of bacteria with washed whole blood cells suspended in autologous serum resulted...... in a dose- and time-dependent adherence to RBCs. The adherence required functionally intact complement receptor 1 (CR1; also called CD35) on the RBCs and significantly inhibited the uptake of P. gingivalis by neutrophils and B cells within 1 min of incubation (by 64% and 51%, respectively...

  6. Framing in the Spanish press about the health crisis because of the E. coli bacterium

    Directory of Open Access Journals (Sweden)

    Paloma López Villafranca

    2013-12-01

    Full Text Available This research article analyses  the approach made by press media and other institutional advertising about the E. coli bacterium, most commonly known as cucumber crisis in Spain. While in the rest of Europe this crisis receives the same treatment as A Flu or mad cow disease in this country it is treated as a crisis that affects to the spanish economy and not to the health of the citizen. Economic interests prevail over public health and this is due to official information given. An analysis of contents of the most popular journals in Spain, according to OJD, is made to prove this hypothesis, El Pais, El Mundo and ABC, as well as a study of the main institutional advertising made about E. coli bacterium by official spanish organizations and the media.

  7. Mitigation of membrane biofouling by a quorum quenching bacterium for membrane bioreactors.

    Science.gov (United States)

    Ham, So-Young; Kim, Han-Shin; Cha, Eunji; Park, Jeong-Hoon; Park, Hee-Deung

    2018-06-01

    In this study, a quorum-quenching (QQ) bacterium named HEMM-1 was isolated at a membrane bioreactor (MBR) plant. HEMM-1 has diplococcal morphology and 99% sequence identity to Enterococcus species. The HEMM-1 cell-free supernatant (CFS) showed higher QQ activities than the CFS of other QQ bacteria, mostly by degrading N-acyl homoserine lactones (AHLs) with short acyl chains. Instrumental analyses revealed that HEMM-1 CFS degraded AHLs via lactonase activity. Under static, flow, and shear conditions, the HEMM-1 CFS was effective in reducing bacterial and activated-sludge biofilms formed on membrane surfaces. In conclusion, the HEMM-1 isolate is a QQ bacterium applicable to the control of biofouling in MBRs via inhibition of biofilm formation on membrane surfaces. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Single-bacterium nanomechanics in biomedicine: unravelling the dynamics of bacterial cells

    International Nuclear Information System (INIS)

    Aguayo, S; Bozec, L; Donos, N; Spratt, D

    2015-01-01

    The use of the atomic force microscope (AFM) in microbiology has progressed significantly throughout the years since its first application as a high-resolution imaging instrument. Modern AFM setups are capable of characterizing the nanomechanical behaviour of bacterial cells at both the cellular and molecular levels, where elastic properties and adhesion forces of single bacterium cells can be examined under different experimental conditions. Considering that bacterial and biofilm-mediated infections continue to challenge the biomedical field, it is important to understand the biophysical events leading towards bacterial adhesion and colonization on both biological and non-biological substrates. The purpose of this review is to present the latest findings concerning the field of single-bacterium nanomechanics, and discuss future trends and applications of nanoindentation and single-cell force spectroscopy techniques in biomedicine. (topical review)

  9. Five new amicoumacins isolated from a marine-derived Bacterium bacillus subtilis

    KAUST Repository

    Li, Yongxin; Xu, Ying; Liu, Lingli; Han, Zhuang; Lai, Pok Yui; Guo, Xiangrong; Zhang, Xixiang; Lin, Wenhan; Qian, Pei-Yuan

    2012-01-01

    Four novel amicoumacins, namely lipoamicoumacins A-D (1-4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature. 2012 by the authors; licensee MDPI.

  10. Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

    KAUST Repository

    Harjes, Janno; Ryu, Tae Woo; Abdelmohsen, Usama Ramadan; Moitinho-Silva, Lucas; Horn, Hannes; Ravasi, Timothy; Hentschel, Ute

    2014-01-01

    The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

  11. Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

    KAUST Repository

    Haroon, Mohamed; Thompson, Luke R.; Stingl, Ulrich

    2016-01-01

    A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column.

  12. Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

    KAUST Repository

    Harjes, Janno

    2014-03-06

    The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

  13. Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

    KAUST Repository

    Haroon, Mohamed

    2016-02-11

    A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column.

  14. Genomic Analysis of Caldithrix abyssi, the Thermophilic Anaerobic Bacterium of the Novel Bacterial Phylum Calditrichaeota

    OpenAIRE

    Kublanov, Ilya V.; Sigalova, Olga M.; Gavrilov, Sergey N.; Lebedinsky, Alexander V.; Rinke, Christian; Kovaleva, Olga; Chernyh, Nikolai A.; Ivanova, Natalia; Daum, Chris; Reddy, T.B.K.; Klenk, Hans-Peter; Spring, Stefan; G?ker, Markus; Reva, Oleg N.; Miroshnichenko, Margarita L.

    2017-01-01

    © 2017 Kublanov, Sigalova, Gavrilov, Lebedinsky, Rinke, Kovaleva, Chernyh, Ivanova, Daum, Reddy, Klenk, Spring, Göker, Reva, Miroshnichenko, Kyrpides, Woyke, Gelfand, Bonch-Osmolovskaya. The genome of Caldithrix abyssi, the first cultivated representative of a phylum-level bacterial lineage, was sequenced within the framework of Genomic Encyclopedia of Bacteria and Archaea (GEBA) project. The genomic analysis revealed mechanisms allowing this anaerobic bacterium to ferment peptides or to impl...

  15. Permanent draft genome of the malachite-green-tolerant bacterium Rhizobium sp. MGL06.

    Science.gov (United States)

    Liu, Yang; Wang, Runping; Zeng, Runying

    2014-12-01

    Rhizobium sp. MGL06, the first Rhizobium isolate from a marine environment, is a malachite-green-tolerant bacterium with a broader salinity tolerance (range: 0.5% to 9%) than other rhizobia. This study sequences and annotates the draft genome sequence of this strain. Genome sequence information provides a basis for analyzing the malachite green tolerance, broad salinity adaptation, nitrogen fixation properties, and taxonomic classification of the isolate. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Five new amicoumacins isolated from a marine-derived Bacterium bacillus subtilis

    KAUST Repository

    Li, Yongxin

    2012-02-03

    Four novel amicoumacins, namely lipoamicoumacins A-D (1-4), and one new bacilosarcin analog (5) were isolated from culture broth of a marine-derived bacterium Bacillus subtilis, together with six known amicoumacins. Their structures were elucidated on the basis of extensive spectroscopic (2D NNR, IR, CD and MS) analysis and in comparison with data in literature. 2012 by the authors; licensee MDPI.

  17. Alteration of the Canine Small-Intestinal Lactic Acid Bacterium Microbiota by Feeding of Potential Probiotics

    OpenAIRE

    Manninen, Titta J. K.; Rinkinen, Minna L.; Beasley, Shea S.; Saris, Per E. J.

    2006-01-01

    Five potentially probiotic canine fecal lactic acid bacterium (LAB) strains, Lactobacillus fermentum LAB8, Lactobacillus salivarius LAB9, Weissella confusa LAB10, Lactobacillus rhamnosus LAB11, and Lactobacillus mucosae LAB12, were fed to five permanently fistulated beagles for 7 days. The survival of the strains and their potential effects on the indigenous intestinal LAB microbiota were monitored for 17 days. Denaturing gradient gel electrophoresis (DGGE) demonstrated that the five fed LAB ...

  18. Comment on "A bacterium that degrades and assimilates poly(ethylene terephthalate)".

    Science.gov (United States)

    Yang, Yu; Yang, Jun; Jiang, Lei

    2016-08-19

    Yoshida et al (Report, 11 March 2016, p. 1196) reported that the bacterium Ideonella sakaiensis 201-F6 can degrade and assimilate poly(ethylene terephthalate) (PET). However, the authors exaggerated degradation efficiency using a low-crystallinity PET and presented no straightforward experiments to verify depolymerization and assimilation of PET. Thus, the authors' conclusions are rather misleading. Copyright © 2016, American Association for the Advancement of Science.

  19. Two New Cholic Acid Derivatives from the Marine Ascidian-Associated Bacterium Hasllibacter halocynthiae

    Directory of Open Access Journals (Sweden)

    Sung Hun Kim

    2012-10-01

    Full Text Available The investigation of secondary metabolites in liquid cultures of a recently discovered marine bacterium, Hasllibacter halocynthiae strain KME 002T, led to the isolation of two new cholic acid derivatives. The structures of these compounds were determined to be 3,3,12-trihydroxy-7-ketocholanic acid (1 and 3,3,12-trihydroxy-7-deoxycholanic acid (2 through HRFABMS and NMR data analyses.

  20. Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium

    OpenAIRE

    Arif, Mohammad; Busot, Grethel Y.; Mann, Rachel; Rodoni, Brendan; Liu, Sanzhen; Stack, James P.

    2016-01-01

    Rathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet reliable detection and diagnostic tools are lacking. To better understand this geographically-isolated plant pathogen, genetic variation as a function of geographic location, host species, and date of...