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

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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.

Cellular polymorphism and nitrogenase activity of Azotobacter nigricans During Kerosene removal

International Nuclear Information System (INIS)

Garcia-Esquivel, G.; Rodriguez-Casasola, T.; Ferrera-Cerrato, R.; Rodriguez-Vazquez, R.; Calva-Calva, G.; Esparza-Garcia, F.

2009-01-01

It has been reported that certain plants grow in soils contaminated with hydrocarbons developing nitrogen-fixing bacteria. for example in the rhizosphere of beams plants grown in soil contaminated with kerosene it was found the presence of Azotobacter which removed kerosene and produced polymorphic cells when they grew in nitrogen free cultures. (Author)

Differential accumulation of nif structural gene mRNA in Azotobacter vinelandii.

Science.gov (United States)

Hamilton, Trinity L; Jacobson, Marty; Ludwig, Marcus; Boyd, Eric S; Bryant, Donald A; Dean, Dennis R; Peters, John W

2011-09-01

Northern analysis was employed to investigate mRNA produced by mutant strains of Azotobacter vinelandii with defined deletions in the nif structural genes and in the intergenic noncoding regions. The results indicate that intergenic RNA secondary structures effect the differential accumulation of transcripts, supporting the high Fe protein-to-MoFe protein ratio required for optimal diazotrophic growth.

Energy supply for dinitrogen fixation by Azotobacter vinelandii and by bacteroids of Rhizobium leguminosarum

NARCIS (Netherlands)

Laane, N.C.M.

1980-01-01

The central issue of this thesis is how obligate aerobes, such as Rhizobium leguminosarum bacteroids and Azotobacter vinelandii, generate and regulate the energy supply (in the form of ATP and reducing equivalents) for nitrogenase.
In an effective

Influence of N-15 labelled urea and azotobacter on corn yield and nitrogen budget as affected by organic matter

Energy Technology Data Exchange (ETDEWEB)

Soliman, S M; Abdelmonem, M A [Soil and Water Dept., Atomic Energy Authority, Cairo, (Egypt)

1995-10-01

As sandy soils of Egypt are poor in their chemical and physical properties, their fertilization with chemical or biological fertilizer is essential. The reported greenhouse experiment was conducted, using sandy soil of Egypt to evaluate the impact of urea fertilizer, applied alone combined with nitrification inhibitors (DCD) or (N-serve) on (corn yield and N-losses) as compared with inoculation with azotobacter under organic matter treatment as soil amendment. Total dry matter was recorded, while N-uptake by corn, and N-recovery due to inoculation with azotobacter was determined using N-15 dilution technique. Data obtained indicated that, application of DCD or N-serve with urea increased corn dry matter weight as well N-15 recovery. Significant increase in N-recovery was obtained due to nitrification inhibitor application and azotobacter inoculation. N-15 losses were reduced due to application of DCD and N-serve from 45% and respectively. Use of bio fertilizers and nitrification inhibitors could play an important role in corn production in sandy soil, as well as decrease the losses of applied N-fertilizers. fig., 3 tabs.

Influence of N-15 labelled urea and azotobacter on corn yield and nitrogen budget as affected by organic matter

International Nuclear Information System (INIS)

Soliman, S.M.; Abdelmonem, M.A.

1995-01-01

As sandy soils of Egypt are poor in their chemical and physical properties, their fertilization with chemical or biological fertilizer is essential. The reported greenhouse experiment was conducted, using sandy soil of Egypt to evaluate the impact of urea fertilizer, applied alone combined with nitrification inhibitors (DCD) or (N-serve) on (corn yield and N-losses) as compared with inoculation with azotobacter under organic matter treatment as soil amendment. Total dry matter was recorded, while N-uptake by corn, and N-recovery due to inoculation with azotobacter was determined using N-15 dilution technique. Data obtained indicated that, application of DCD or N-serve with urea increased corn dry matter weight as well N-15 recovery. Significant increase in N-recovery was obtained due to nitrification inhibitor application and azotobacter inoculation. N-15 losses were reduced due to application of DCD and N-serve from 45% and respectively. Use of bio fertilizers and nitrification inhibitors could play an important role in corn production in sandy soil, as well as decrease the losses of applied N-fertilizers. fig., 3 tabs

Interaction of technetium and molybdenum in nitrogenase inhibition in Azotobacter chroococcum

International Nuclear Information System (INIS)

Vandecasteele, C.M.; Henrot, J.; Van Hove, C.; Myttenaere, C.; Cogneau, M.

1986-01-01

Azotobacter chroococcum cultures were grown with and without Tc, using 99 Mo and sup(95m)Tc as Mo and Tc tracers. Tc does inhibit nitrogenase and Mo accumulation, but does not affect the Mo content of nitrogenase MoFe protein and seems to have less affinity for this than for protein compounds in general. Hence the inhibition is unlikely to be due to substitution of Mo by Tc. (UK)

EFFECT OF HEAVY METAL IONS ON THE NUMBER AND ACTIVITY OF Azotobacter AND MELANINSYNTHESIZING MICROMYCETES

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Malynovska I. M.

2017-06-01

Full Text Available The aim of the work was to determine the possibility of using the number and activity of Azotobacter cells and melanin-synthesizing micromycetes as indicators of gray forest soils of different types (fallow, extensive and intensive agrosoil pollution with heavy metal ions. For this purpose, there were used laboratory-analytical, microbiological and statistical methods. As a result of research of increasing doses of heavy metals (zinc + lead influence on the number of microorganisms in the gray forest soils it was found that the number and activity of Azotobacter and the number and part of melanin-synthesizing micromycetes in their total number may be fit into indicators of pollution with heavy metals. Azotobacter cells activity index may be considered indicative at contamination levels of 5-100 of maximum permissible concentration in the absence of vegetation, at contamination levels of 10–100 – for soils with phytocenosis. The number and proportion of melaninsynthesizing micromycetes in total guantity may serve as diagnostic sign of gray forest soils pollution with high doses of heavy metals, but only for the period of contamination up to 2 years. It was shown that nature of the effect of heavy metals on the number of microorganisms of indicative groups depended on the presence of plants in the monitoring system, on doses of heavy metals, on the term of contamination and on the type of soil usage.

Batch culture of Azotobacter vinelandii under oxygen limitation conditionS

Energy Technology Data Exchange (ETDEWEB)

Camacho Rubio, F.; Martinez Nieto, L.; Fernandez Serrano, M.; Jimenez Moleon, M.C. [Departamento de Ingenieria Quimica, Universidad de Granada, Granada (Spain)

1996-12-01

The batch culture of Azotobacter vinealandii on glucose under nitrogen-fixing conditions, seeking oxygen limitation conditions, has been studied in order to use it as a Biological Test System for the experimental study of oxygen transfer enhancement methods in aerobic fermenters. overall kinetic parameters for exponential growth and for linear growth (under oxygen limitation) have been determined. It was noted an appreciable influence of the oxygen transfer rate on glucose and oxygen uptake, which seems to be due to alginate production, excreted as a nitrogenase protection mechanisms. (Author) 12 refs.

Study the concentration of macroelements in forage mays (Zea mays L. (SC 704 as effected by inoculation with mycorrhizal fungi and Azotobacter chroococcum under different levels of nitrogen

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M. Amirabadi

2016-05-01

Full Text Available Nitrogen and phosphorus are two necessary macronutrients for plant growth and yield. These two elements now will be added to soil by chemical fertilizers. This research has been carried out based on randomized completely block design with three replications at Markazi Provience Agricultural Research Station, Iran, during growing season of 2004-2005 to evaluate the effects of Azotobacter chroococcum and Mycorrhiza (Glomus intraradices as biofertilizers and urea as chemical fertilizers on concentrations of N, P, K, Na, Ca and crude protein (% in corn (Zea mays L. shoot tissues and dry matter of corn. Azotobacter chroococcum used as two levels (inoculated and uninoculated, mycorrhiza (Glomus intraradices in two levels (inoculated and uninoculated and urea in four levels (0, 75, 150 and 300 kg.ha-1. Results showed that Azotobacter chroococcum affected significantly all studied criteria except of K shoot concentration, but mycorrhizan (Glomus intraradices only had a increasing significantly effect on N, K, Na and Crude protein. The interaction between Azotobacter chroococcum and Mycorrhiza (Glomus intraradices had the most increasing effect on dry matter, N, Na and Crude protein. Therefore, based on our results it can be concluded that in order to prevent polluting the agricultural soil, environmental and other water supplies from nitrogen chemical fertilizers, application of Azotobacter chroococcum or combined with mycorrhizal fungi with 150 kg.ha-1 Urea is recommended.

Poly(3-Hydroxybutyrate) Synthesis Genes in Azotobacter sp. Strain FA8

OpenAIRE

Pettinari, M. Julia; Vázquez, Gustavo J.; Silberschmidt, Daniel; Rehm, Bernd; Steinbüchel, Alexander; Méndez, Beatriz S.

2001-01-01

Genes responsible for the synthesis of poly(3-hydroxybutyrate) (PHB) in Azotobacter sp. FA8 were cloned and analyzed. A PHB polymerase gene (phbC) was found downstream from genes coding for β-ketothiolase (phbA) and acetoacetyl-coenzyme A reductase (phbB). A PHB synthase mutant was obtained by gene inactivation and used for genetic studies. The phbC gene from this strain was introduced into Ralstonia eutropha PHB-4 (phbC-negative mutant), and the recombinant accumulated PHB when either glucos...

Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils

NARCIS (Netherlands)

Jiménez Avella, Diego; Montaña, José Salvador; Martínez, María Mercedes

With the purpose of isolating and characterizing free nitrogen fixing bacteria (FNFB) of the genus Azotobacter, soil samples were collected randomly from different vegetable organic cultures with neutral pH in different zones of Boyacá-Colombia. Isolations were done in selective free nitrogen

The Effect of Inoculation with Azotobacter and Nitrogen Levels on Grain and Corn Yield Components at Simultaneous Cropping System with Legumes

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mohammad mirzakhani

2017-09-01

Full Text Available Introduction: Corn has been regarded as one of the important crops from the view point of both human and animal feeding resource. Intercropping defined as cultivation of two or more species together. The advantages of intercropping can be included: efficient use of water and sunlight, exchange of nutrients, weed competition reduction, reduction of pathogens and the increase of soil fertility. Research shows that intercropping combinations of legume–grass will increase forage quality. Because, grasses Grains have a lot of carbohydrates and legumes are rich in protein and vitamins. This study was conducted to evaluate the effect of inoculation with azotobacter and nitrogen levels on grain and corn yield components at simultaneous cropping system with legumes under the weather conditions of Markazi province. Materials and methods: This study was carried out at agricultural research field of Payame Noor University, Arak Branch during 2011. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Methods of plant nutrition (M0= inoculation with azotobacter, M1= inoculation with azotobacter + 37/5 Kg ha-1 of rare nitrogen with foliar application method, M2= inoculation with azotobacter + 150 Kg ha-1 of rare nitrogen mix with soil and simultaneous cropping treatment of legumes, [S1= corn + alfalfa (Medicago sativa L., S2= corn + bitter vetch (Lathyrus sativus L., S3= corn + mung bean (Vigna radiata L., S4= corn + chickpea (Cicer arientinum L., S5= corn + vetch (Vicia ervillia L. ] were assigned in plots. Each sub plot consisted of 4 rows, 6 m long with 60 cm between rows space and 20 cm between plants on the rows and S.C Apex hybrid was used. In this study characteristics such as: plant height, earing height, the number of grains per m-2, the number of rows per ear, the number of grains per row, surface of ear leaf, grain yield of corn, 1000 grain weight, harvest index of corn, nitrogen use

Crystallization and preliminary crystallographic data of the PAS domain of the NifL protein from Azotobacter vinelandii.

NARCIS (Netherlands)

Hefti, M.H.; Hendle, J.; Enroth, C.; Vervoort, J.J.M.; Tucker, P.A.

2001-01-01

The Azotobacter vinelandii NifL protein is a redox-sensing flavoprotein which inhibits the activity of the nitrogen-specific transcriptional activator NifA. The N-terminal PAS domain has been overexpressed in Escherichia coli and crystallized by the hanging-drop vapour-diffusion method. The crystal

Physical and genetic map of the major nif gene cluster from Azotobacter vinelandii.

OpenAIRE

Jacobson, M R; Brigle, K E; Bennett, L T; Setterquist, R A; Wilson, M S; Cash, V L; Beynon, J; Newton, W E; Dean, D R

1989-01-01

Determination of a 28,793-base-pair DNA sequence of a region from the Azotobacter vinelandii genome that includes and flanks the nitrogenase structural gene region was completed. This information was used to revise the previously proposed organization of the major nif cluster. The major nif cluster from A. vinelandii encodes 15 nif-specific genes whose products bear significant structural identity to the corresponding nif-specific gene products from Klebsiella pneumoniae. These genes include ...

Production of polyhydroxybutyrate and alginate from glycerol by Azotobacter vinelandii under nitrogen-free conditions

OpenAIRE

Yoneyama, Fuminori; Yamamoto, Mayumi; Hashimoto, Wataru; Murata, Kousaku

2015-01-01

Glycerol is an interesting feedstock for biomaterials such as biofuels and bioplastics because of its abundance as a by-product during biodiesel production. Here we demonstrate glycerol metabolism in the nitrogen-fixing species Azotobacter vinelandii through metabolomics and nitrogen-free bacterial production of biopolymers, such as poly-d-3-hydroxybutyrate (PHB) and alginate, from glycerol. Glycerol-3-phosphate was accumulated in A. vinelandii cells grown on glycerol to the exponential phase...

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

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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.

PRODUCTION AND RECOVERY OF POLY-Β-HYDROXYBUTYRATE FROM WHEY DEGRADATION BY AZOTOBACTER

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A. Khanafari , A. Akhavan Sepahei, M. Mogharab

2006-07-01

Full Text Available Three strains of Azotobacter chroococcum were studied to produce poly-β hydroxybutyrate as a inclusion body by whey degradation. Optimum degradation whey results were obtained when using whey broth as a fermentation medium without extra salt, temperature at 35 °C and pH 7 (P<0.05. Lambda max for whey broth medium was determined probably about 400 nm. The effect of different nitrogenous rich compounds (NH4NO3, Bactopeptone, Casein, Yeast extract, Meat extract, Protease peptone and Tryptone on whey degradation showed that incorporation of nitrogenous compounds into the medium did not increase whey degradation by Azotobacter chroococcum 1723 (P<0.05. But poly-β hydroxyl-butyrate production was increased in presence Meat extract up to 75% of the cell dry weight after 48h. The addition of nitrogenous sourced (except ammonium nitrate had a positive effect on poly-β hydroxyl-butyrate production as it peaked in the presence of Meat extract and 4.43 g/L was accumulated in comparison to 0.5g at diazotrophically growing cells. Increasing the O2 values resulted by shaking at 122 rpm in decreased poly-β hydroxyl-butyrate yield form 4.43 to 0.04 g/L. The results show that this medium supports the growth of strain 1735 and also that this waste could be utilized as a carbon and nitrogen source. Production of poly-β hydroxyl-butyrate by using whey as a medium looks promising, since the use of inexpensive feed-stocks for poly-β hydroxyl-butyrate is essential if bioplastics are to become competitive products.

Comparative toxicity of heavy metal ions for some microorganisms. [Rhodotorula; Hansenula anormala; T. utilis; Serratia; Azotobacter; Pseudomonas; Escherichia coli; yeasts

Energy Technology Data Exchange (ETDEWEB)

Avakyan, Z A

1967-01-01

Polarographic study of Pb/sup 2 +/, Cd/sup 2 +/, Co/sup 2 +/, and Ni/sup 2 +/ concentration in different media has shown that at pH 6.0, Pb/sup 2 +/ is always precipitated by phosphates and cannot be determined polarographically. Cd, Co and Ni content is somewhat lower than that found in water solutions. The effect of Ag, Hg, Co, Ni, Pb, and Cd ions on the growth of 3 strains of Rhodotorula, Hansenula anomala and T. utilis, 6 strains of Serratia, 6 strains of Azotobacter, 12 strains of Pseudomonas and 2 strains of E. coli was studied. According to their toxicity for the microoganisms tested, heavy metals should be arranged in the following order: Ag>Hg>Cogreater than or equal toNi>Cd. Yeasts are the least sensitive to the action of heavy metals, cf. come serratia, Pseudomonas, Azotobacter and E. coli.

EFFECT OF HEAVY METAL IONS ON THE NUMBER AND ACTIVITY OF Azotobacter AND MELANINSYNTHESIZING MICROMYCETES

OpenAIRE

Malynovska I. M.

2017-01-01

The aim of the work was to determine the possibility of using the number and activity of Azotobacter cells and melanin-synthesizing micromycetes as indicators of gray forest soils of different types (fallow, extensive and intensive agrosoil) pollution with heavy metal ions. For this purpose, there were used laboratory-analytical, microbiological and statistical methods. As a result of research of increasing doses of heavy metals (zinc + lead) influence on the number of microorganisms in the g...

Effects of macro nutrient concentration on biological N2 fixation by Azotobacter vinelandii ATCC 12837

International Nuclear Information System (INIS)

Liew Pauline Woan Ying; Nazalan Najimudin; Jong Bor Chyan; Latiffah Noordin; Khairuddin Abdul Rahim; Amir Hamzah Ahmad Ghazali

2010-01-01

The dynamic changes of biological N 2 fixation by Azotobacter vinelandii ATCC 12837 under the influence of various macro nutrients, specifically phosphorus (P) and potassium (K), was investigated. In this attempt, Oryza sativa L. var. MR 219 was used as the model plant. Results obtained showed changes in the biological N 2 fixation activities with different macro nutrient(s) manipulations. The research activity enables optimisation of macro nutrients concentration for optimal/ enhanced biological N 2 fixation by A. vinelandii ATCC 12837. (author)

Influence of l-amino acids on aggregation and biofilm formation in Azotobacter chroococcum and Trichoderma viride.

Science.gov (United States)

Velmourougane, K; Prasanna, R

2017-10-01

The effects of l-amino acids on growth and biofilm formation in Azotobacter chroococcum (Az) and Trichoderma viride (Tv) as single (Az, Tv) and staggered inoculated cultures (Az-Tv, Tv-Az) were investigated. A preliminary study using a set of 20 l-amino acids, identified 6 amino acids (l-Glu, l-Gln, l-His, l-Ser, l-Thr and l-Trp) which significantly enhanced growth and biofilm formation. Supplementation of these amino acids at different concentrations revealed that 40 mmol l -1 was most effective. l-Glu and l-Gln favoured planktonic growth in both single and in staggered inoculated cultures, while l-Trp and l-Thr, enhanced aggregation and biofilm formation. Addition of l-Glu or l-Gln increased carbohydrate content and planktonic population. Principal component analysis revealed the significant role of proteins in growth and biofilm formation, particularly with supplementation of l-Trp, l-Thr and l-Ser. Azotobacter was found to function better as biofilm under staggered inoculated culture with Trichoderma. The results illustrate that amino acids play crucial roles in microbial biofilm formation, by influencing growth, aggregation and carbohydrates synthesized. The differential and specific roles of amino acids on biofilm formation are of significance for agriculturally important micro-organisms that grow as biofilms, colonize and benefit the plants more effectively. © 2017 The Society for Applied Microbiology.

EFECTO DE AGROQUÍMICOS PELETIZADOS EN SEMILLAS DE ALGODÓN SOBRE EL BIOFERTILIZANTE MONIBAC® CON BASE EN Azotobacter chroococcum EFEITO DE AGROQUÍMICOS PELETIZADOS EM SEMENTES DE ALGODÃO SOBRE 0 BIOLFERTILIZANTE MONIBAC® CONTENDO Azotobacter chroococcum EFFECT OF AGROCHEMICALS IN COTTON SEED PELLETS ON MONIBAC® BIOFERTILISER BASED ON Azotobacter chroococcum

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DIEGO RIVERA

2011-12-01

Full Text Available En la presente investigación, se analizó la influencia in vitro de los plaguicidas peletizados simultáneamente con el fungicida (principios activos: carboxin: 5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3 carboxamide y tiram: tetramethylthioperoxydicarbonic diamide y un insecticida (principio activo: malatión: S-1,2-Bis(ethoxycarbonylethyl-0,0 imethylthiophosphate en las semillas de algodón sobre la viabilidad del biofertilizante Monibac®-Corpoica con base en Azotobacter chroococcum AC1, cuando fueron aplicados conjuntamente en bandejas experimentales. Se analizó la práctica de recubrir las semillas con los agroquímicos como posible causa de descenso poblacional de la bacteria bajo este modelo de aplicación. Los resultados obtenidos por el Test de Duncan (pNo presente trabalho foi analisado a influencia in vitro dos plaguicidas peletizados simultáneamente com os fungicidas carboxin (5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-Z carboxamide e tiram (tetramethylthioperoxydicarbonic diamide alem do inseticida malation (S-1,2 Bis(ethoxycarbonylethyl-0,0 imethylthiophosphate nas sementes de algodÃo sobre a viabilidade do biofertilizante Monibac - Corpoica contendo Azotobacter chroococcum, estirpe AC1, quando foram aplicados conjuntamente em bandejas experimentais. Foi analisado a pratica de recobrimento das sementes com os agroquímicos como possível causa da diminuição populacional das bacterias submetidas a este modelo de aplicação. Os resultados obtidos pelo teste Duncan (pIn this study, we analyzed the influence of pesticides in vitro pellet simultaneously with the fungicide (active ingredient: carboxin: 5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-Z carboxamide and tiram: tetramethylthioperoxydicarbonic diamide and an insecticide (active ingredient: Malathion: S-1,2-Bis (ethoxycarbonyl ethyl-0, O-dimethylthiophosphate in cotton seeds on the viability of biofertiliser Monibac® -based Corpoica Azotobacter chroococcum ACT, when

Evaluación de la estabilidad de Trichoderma sp. y Azotobacter sp. conservados por diferentes métodos

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Yvonne Sarmiento Rangel

2013-01-01

Full Text Available Título en ingles: Evaluation of the stability of Trichoderma sp. and Azotobacter sp.  preserved by different methods Resumen En el Laboratorio de Microbiología Aplicada de la Universidad Francisco de Paula Santander (Cúcuta, Colombia constantemente ingresan al Banco de Cepas, cultivos microbianos de interés biotecnológico, especialmente del sector agrícola, los cuales son utilizados en las actividades de docencia e investigación.  Por esta razón, existe el interés de mantener viables a través del tiempo estos cultivos microbianos, para lo cual se realizó en esta investigación, la evaluación de la estabilidad de los aislados de Trichoderma sp. y Azotobacter sp., utilizando  las técnicas de conservación  en viales con solución salina estéril (0,85% NaCl en refrigeración (4°C y temperatura ambiente (30°C, suelo estéril en refrigeración (4°C, comparados con la metodología de repiques sucesivos como tratamiento control.  Los resultados no mostraron diferencias significativas según el Test de Duncan (P≤0,05 en  la tasa de supervivencia microbiana entre los métodos de conservación. Sin embargo, se observó en las técnicas de viales con solución salina  estéril y suelo estéril mantenidos en refrigeración, mayor estabilidad en la concentración celular durante los cuatros meses de evaluación, sin registrar contaminación en los cultivos.  Así mismo, se registró un óptimo crecimiento macroscópico de los cultivos microbianos y sus características microscópicas se mantuvieron estables en estos dos métodos de conservación.  Por esta razón, se seleccionaron como técnicas de conservación de estos microorganismos, teniendo en cuenta además, ventajas como la facilidad de la técnica, disponibilidad de equipos, materiales y personal con los que se cuenta en el laboratorio.  Palabras clave: banco de cepas, conservación de microorganismos, viabilidad celular, Trichoderma sp., Azotobacter sp. Abstract In the

Investigation on Strain Development of Azotobacter chroococcum through Chemical Mutagenesis for Indole Acetic Acid Production

International Nuclear Information System (INIS)

Ye Lin Win; Myo Myint Han; Myo Myint

2010-12-01

Two wild strains of Azotobacter chroococcum were mutagenized by various concentration of NTG (.005% , .0075% and .01%) for 1 hour. The IAA producing activity of 12 effective mutagenized strains were quantitatively measured by UV spectroscopic method. Mutagenized strains M1 and M2 from W1, and M8 and M9 from W2 were selected. Their IAA productivities were 300.498, 216.290, 238.436 and 190.856 ppm, respectively. M1and M9 were higher IAA productivity with greater quality. In germination, M1, M8 and M9 can promote the plant growth compare with commercial IAA.

Determinación del potencial promotor del crecimiento vegetal de Azotobacter spp. aislados de la rizósfera de malezas en cultivos de maíz (Zea mays L.

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Luis H. León

2015-01-01

Full Text Available Los fertilizantes químicos representan entre 20% y 30% de los costos de producción de un cultivo, utilizados correctamente incrementan la productividad y rentabilidad; sin embargo, cada año aumenta la cantidad de fertilizantes por aplicar, debido a la deficiencia de adsorción en el suelo y absorción por la planta. Siendo el maíz el tercer cultivo de importancia en Perú, con un impacto significativo en la actividad económica y social, en el 2014, solo el 40% del maíz ofertado correspondió a la producción nacional. En busca de alternativas para disminuir el uso de fertilizantes químicos se realizan investigaciones con denominadas rizobacterias promotoras del crecimiento vegetal (PGPR, por sus siglas en ingles. Se identificaron 37 malezas en cultivos de maíz procedentes de campos agrícolas de los distritos de Monsefú y Reque, Región Lambayeque, siendo dicotiledóneas predominantes con 68 % con respecto a monocotiledóneas con 32%. Las bacterias se aislaron de la rizósfera de malezas, obteniendo 305 cultivos puros de bacterias, de los cuales 133 cultivos puros (43,7% se identificaron como Azotobacter spp., investigándose su reacción bioquímica en reducción de nitratos, utilización de sacarosa, glucosa, maltosa, manitol, ramnosa, glicerol y sorbitol, identificándose A. vinelandii (58%, A. paspali (13%, A. armeniacus (8%, A. nigricans (8% y en 13 cultivos no se identificó la especie. Con los cultivos Azotobacter spp. se cuantificó hasta 36,03 ppm de nitrógeno fijado como amonio; 60,75 ppm de ácido indol acético y 6,06 ppm de fósforo solubilizado, se determinó actividad antagónica contra Fusarium verticillioides, proteolítica y quitinolítica y. El 20% de Azotobacter spp. no afectó la emergencia de maíz amarillo duro hibrido simple AGRI- 144, el 33 % la afectó positivamente y el 47% la afectó negativamente. A su vez, ningún Azotobacter spp. afectó la sobrevivencia. Demostrándose el potencial promotor del

Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils

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Diego Javier Jiménez

2011-09-01

Full Text Available With the purpose of isolating and characterizing free nitrogen fixing bacteria (FNFB of the genus Azotobacter, soil samples were collected randomly from different vegetable organic cultures with neutral pH in different zones of Boyacá-Colombia. Isolations were done in selective free nitrogen Ashby-Sucrose agar obtaining a recovery of 40%. Twenty four isolates were evaluated for colony and cellular morphology, pigment production and metabolic activities. Molecular characterization was carried out using amplified ribosomal DNA restriction analysis (ARDRA. After digestion of 16S rDNA Y1-Y3 PCR products (1487pb with AluI, HpaII and RsaI endonucleases, a polymorphism of 16% was obtained. Cluster analysis showed three main groups based on DNA fingerprints. Comparison between ribotypes generated by isolates and in silico restriction of 16S rDNA partial sequences with same restriction enzymes was done with Gen Workbench v.2.2.4 software. Nevertheless, Y1-Y2 PCR products were analysed using BLASTn. Isolate C5T from tomato (Lycopersicon esculentum grown soils presented the same in silico restriction patterns with A. chroococcum (AY353708 and 99% of similarity with the same sequence. Isolate C5CO from cauliflower (Brassica oleracea var. botrytis grown soils showed black pigmentation in Ashby-Benzoate agar and high similarity (91% with A. nigricans (AB175651 sequence. In this work we demonstrated the utility of molecular techniques and bioinformatics tools as a support to conventional techniques in characterization of the genus Azotobacter from vegetable-grown soils.

Alginate Biosynthesis in Azotobacter vinelandii: Overview of Molecular Mechanisms in Connection with the Oxygen Availability

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Ivette Pacheco-Leyva

2016-01-01

Full Text Available The Gram-negative bacterium Azotobacter vinelandii can synthetize the biopolymer alginate that has material properties appropriate for plenty of applications in industry as well as in medicine. In order to settle the foundation for improving alginate production without compromising its quality, a better understanding of the polymer biosynthesis and the mechanism of regulation during fermentation processes is necessary. This knowledge is crucial for the development of novel production strategies. Here, we highlight the key aspects of alginate biosynthesis that can lead to producing an alginate with specific material properties with particular focus on the role of oxygen availability linked with the molecular mechanisms involved in the alginate production.

Mutant Forms of the Azotobacter vinelandii Transcriptional Activator NifA Resistant to Inhibition by the NifL Regulatory Protein

OpenAIRE

Reyes-Ramirez, Francisca; Little, Richard; Dixon, Ray

2002-01-01

The Azotobacter vinelandii σ54-dependent transcriptional activator protein NifA is regulated by the NifL protein in response to redox, carbon, and nitrogen status. Under conditions inappropriate for nitrogen fixation, NifL inhibits transcription activation by NifA through the formation of the NifL-NifA protein complex. NifL inhibits the ATPase activity of the central AAA+ domain of NifA required to drive open complex formation by σ54-RNA polymerase and may also inhibit the activator-polymeras...

Transcriptional Profiling of Nitrogen Fixation in Azotobacter vinelandii▿†

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Hamilton, Trinity L.; Ludwig, Marcus; Dixon, Ray; Boyd, Eric S.; Dos Santos, Patricia C.; Setubal, João C.; Bryant, Donald A.; Dean, Dennis R.; Peters, John W.

2011-01-01

Most biological nitrogen (N2) fixation results from the activity of a molybdenum-dependent nitrogenase, a complex iron-sulfur enzyme found associated with a diversity of bacteria and some methanogenic archaea. Azotobacter vinelandii, an obligate aerobe, fixes nitrogen via the oxygen-sensitive Mo nitrogenase but is also able to fix nitrogen through the activities of genetically distinct alternative forms of nitrogenase designated the Vnf and Anf systems when Mo is limiting. The Vnf system appears to replace Mo with V, and the Anf system is thought to contain Fe as the only transition metal within the respective active site metallocofactors. Prior genetic analyses suggest that a number of nif-encoded components are involved in the Vnf and Anf systems. Genome-wide transcription profiling of A. vinelandiicultured under nitrogen-fixing conditions under various metal amendments (e.g., Mo or V) revealed the discrete complement of genes associated with each nitrogenase system and the extent of cross talk between the systems. In addition, changes in transcript levels of genes not directly involved in N2fixation provided insight into the integration of central metabolic processes and the oxygen-sensitive process of N2fixation in this obligate aerobe. The results underscored significant differences between Mo-dependent and Mo-independent diazotrophic growth that highlight the significant advantages of diazotrophic growth in the presence of Mo. PMID:21724999

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

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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

Screening of Azotobacter isolates for PGP properties and antifungal activity

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Bjelić Dragana Đ.

2015-01-01

Full Text Available Аmong 50 bacterial isolates obtained from maize rhizospherе, 13 isolates belonged to the genus Azotobacter. Isolates were biochemically characterized and estimated for pH and halo tolerance ability and antibiotic resistance. According to characterization, the six representative isolates were selected and further screened in vitro for plant growth promoting properties: production of indole-3-acetic acid (IAA, siderophores, hydrogen cyanide (HCN, exopolysaccharides, phosphate solubilization and antifungal activity (vs. Helminthosporium sp., Macrophomina sp., Fusarium sp.. Beside HCN production, PGP properties were detected for all isolates except Azt7. All isolates produced IAA in the medium without L-tryptophan and the amount of produced IAA increased with concentration of precursor in medium. The highest amount of IAA was produced by isolates Azt4 (37.69 and 45.86 μg ml-1 and Azt5 (29.44 and 50.38 μg ml-1 in the medium with addition of L-tryptophan (2.5 and 5 mM. The isolates showed the highest antifungal activity against Helminthosporium sp. and the smallest antagonistic effect on Macrophomina sp. Radial Growth Inhibition (RGI obtained by the confrontation of isolates with tested phytopathogenic fungi, ranged from 10 to 48%. [Projekat Ministarstva nauke Republike Srbije, br. TR 31073

Influencia de la materia orgánica y Azotobacter nigricans en un cultivo de Stevia rebaudiana B

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Daniel Borda-Molina

2011-12-01

Full Text Available Influence of organic matter and Azotobacter nigricans on a Stevia rebaudiana B. plantation Stevia rebaudiana is a plant thataccumulates a non-caloric sweetener compound known as stevioside. This crop is traditionally fertilized with chemicals that areharmful for the ecosystem, forcing to find organic alternatives to mitigate this damage. Objective. To study the effect of organic matterand an Azotobacter nigricans-based bio-fertilizer on a Stevia rebaudiana plantation grown in acidic soil in the Department of Meta,Colombia. Materials and methods. Five treatments were established: T1 and T2 with the application of home organic waste compostat concentrations of 15 and 30 ton ha-1. T3 and T4 with the same compost concentrations and inoculating the A. nigricans bio-fertilizer.T5 contained the bio-fertilizer alone. The control consisted of the application of the Bokashi compost under the usual conditions ofcultivation. Plant growth was assessed by biomass increase measured as dry weight, production, and leaf area. The physicochemicalanalysis of soil included: percentage of organic carbon, water content, and pH. Results. The inoculation of the bio-fertilizer produced an increase in the rate of mineralization of compost, reaching a final 4.85% of OC between 90 and 180 days after inoculation. There were significant (p< 0.05 differences between biomass production with T2 (1,538 kg ha-1 and the control (477 kg ha-1. Regarding the soluble solid content, T1, T3 and T4 showed the highest °Brix values (12.4, 12.35 and 12.15, respectively. Conclusions. The concentration of 30 ton ha-1 produced the highest biomass production and the application of the biofertilizer showed a positive correlation with compost mineralization and glucoside synthesis.

Site-directed mutagenesis of Azotobacter vinelandii ferredoxin I: [Fe-S] cluster-driven protein rearrangement

International Nuclear Information System (INIS)

Martin, A.E.; Burgess, B.K.; Stout, C.D.; Cash, V.L.; Dean, D.R.; Jensen, G.M.; Stephens, P.J.

1990-01-01

Azotobacter vinelandii ferredoxin I is a small protein that contains one [4Fe-4S] cluster and one [3Fe-4S] cluster. Recently the x-ray crystal structure has been redetermined and the fdxA gene, which encodes the protein, has been cloned and sequenced. Here the authors report the site-directed mutation of Cys-20, which is a ligand of the [4Fe-4S] cluster in the native protein, to alanine and the characterization of the protein product by x-ray crystallographic and spectroscopic methods. The data show that the mutant protein again contains one [4Fe-4S] cluster and one [3Fe-4S] cluster. The new [4Fe-4S] cluster obtains its fourth ligand from Cys-24, a free cysteine in the native structure. The formation of this [4Fe-4S] cluster drives rearrangement of the protein structure

Cloning and Expression of Three New Azotobacter vinelandii Genes Closely Related to a Previously Described Gene Family Encoding Mannuronan C-5-Epimerases

OpenAIRE

Svanem, Britt Iren Glærum; Skjåk-Bræk, Gudmund; Ertesvåg, Helga; Valla, Svein

1999-01-01

The cloning and expression of a family of five modular-type mannuronan C-5-epimerase genes from Azotobacter vinelandii (algE1 to -5) has previously been reported. The corresponding proteins catalyze the Ca2+-dependent polymer-level epimerization of β-d-mannuronic acid to α-l-guluronic acid (G) in the commercially important polysaccharide alginate. Here we report the identification of three additional structurally similar genes, designated algE6, algE7, and algY. All three genes were sequenced...

Manipulation and Characterization of Alginate Exo polysaccharides produced by Azotobacter Vinelandii

International Nuclear Information System (INIS)

El-Bialy, H.A.

2011-01-01

Exo polysaccharides (EPS) have been found in a wide range of applications in food industry and in the biomedical field. In the present study, the effect of nutritional factors (carbon and nitrogen sources) and gamma irradiations on alginate production by Azotobacter vinelandii was investigated. To understand the direct and indirect relations among these variables, a two way factorial design experiment was set up. At low concentration of carbon source (≤ 20 g/l), the alginate yield was influenced by the type of nitrogen substrate and C/N ratio, whereas the role of these factors on alginate production was minimized at high concentration of carbon source (> 20 g/l). Batch fermentation of alginate exo polysaccharides was manipulated by maintaining the ph value of the cultures at 7 along the incubation period and reducing the agitation speed to 100 rpm after 24 h at the time of inoculation. This process succeeded to increase the alginate yield exponentially with time by 50%. Exposing A. vinelandii cells to gamma irradiation at dose level 0.5 kGy decreased their activity to synthesis alginate by 44%. The produced alginate was characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) and differential scanning calorimeter (DSC).

[Formation and function of the bean-rhizobium symbiosis in soy plants upon introduction of strains of Azotobacter and Bacillus species].

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Mel'nikova, N N; Bulavenko, L V; Kurdish, I K; Titova, L V; Kots', S Ia

2002-01-01

The effects of bacteria belonging to the genera Azotobacter and Bacillus in a mixed culture with Bradyrhizobium japonicum strains on formation and function of the legume-rhizobium symbiosis of soybean plants were studied. The data showed that the bacterial compositions B. japonicum 634b + B. subtilis 5, B. japonicum 634b + A. chroococcum 20, and B. japonicum 10k + A. vinelandii 56 with a cell ratio of 1:0.1 increased the number and weight of root nodules as well as the height and weight of the aboveground plant parts in almost all the cases by 22-105% compared with the control variants. These binary microbial cultures may be used for development of combined bacterial preparations for soybean.

Caracterización de cepas nativas de Azotobacter spp. y su efecto en el desarrollo de Lycopersicon esculentum Mill. “tomate” en Lambayeque

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Cynthia Escobar

2011-01-01

Full Text Available El objetivo de la presente investigación fue caracterizar y determinar el efecto de cepas nativas de Azotobacter spp. en el desarrollo vegetativo de Lycopersicon esculentum Mill. “tomate”, como una alternativa al uso indiscriminado de fertilizantes químicos. Se tomaron muestras de raíces y suelo rizosférico de hortalizas con las que se realizaron diluciones (10-4 en caldo Ashby-Sacarosa y se incubaron a 30 ºC hasta observar un color amarillo, turbidez y película superficial. El género Azotobacter se identificó en agar mineral sin nitrógeno y Ashby-Benzoato, obteniéndose 96 cepas con una producción de 7.10 a 57.99 mgL-1 de ácido indolacético, 0.13 a 1.64 mgL-1 de nitrógeno fijado como amonio y hasta 1.61 % de eficiencia en la solubilización de roca fosfórica de Bayóvar. Se obtuvo una suspensión celular (108 de cada una de las cuatro cepas con los mayores valores y se inocularon independientemente y en consorcio, así como una combinación con 50 % de urea-100 % de roca fosfórica, en la rizósfera de tomate cv. Río Grande, en un diseño experimental completamente aleatorio. Todas las cepas nativas incrementaron la altura, volumen radicular, materia seca total, parte aérea y radicular frente al testigo absoluto.

Gnotobiotic cultures of rice plants up to ear stage in the absence of combined nitrogen source but in the presence of free living nitrogen fixing bacteria Azotobacter vinelandii and Rhodopseudomonas capsulata

International Nuclear Information System (INIS)

Maudinas, B.; Chemardin, M.; Yovanovitch, E.; Gadal, P.

1981-01-01

An all glass tight growth chamber, entirely sterilizable, has been constructed to carry out axenic and gnotobiotic cultures of rice plants (Oryza sativa L.). When grown in liquid medium and in the absence of combined nitrogen but in the presence of the diazotrophs Azotobacter vinelandii and Rhodopseudomonas capsulata, rice plants exhibited a complete biological cycle from germination up to ear stage, during a period of time similiar to the one encountered in French paddy soil of Camargue. In one experiment, mannitol was given to rice culture medium together with Azotobacter vinelandii and Rhodopseudomonas capsulata. In another experiment, mannitol was not given together with Rhodopseudomonas, and still positive nitrogen gain was obtained, although it was less than culture with mannitol. When 15 N labeled cells of Rhodopseudomonas were added in rice culture medium, 15 N was partly transferred to rice plant. Among the nitrogen substances excreted from the bacteria in the rhizosphere medium, large organic molecules were shown to be the most abundant in our experimental conditions. Moreover, the concentration of free ammonia or aminoacids present in the rice rhizosphere were always compatible with a bacterial nitrogenase activity. (orig.)

Physiology and biochemistry of polysaccharide production by Azotobacter vinelandii and Pseudomonas aeruginosa

Energy Technology Data Exchange (ETDEWEB)

Annison, G.

1985-01-01

The extracellular production and the composition of the acetylated alginates of Azotobacter vinelandii and Pseudomonas aeruginosa were investigated. A reverse-phase HPLC method to determine D-mannuronate/L-guluronate (M/G) ratios in alginates was developed. Comparison between the HPLC procedure and a /sup 1/H-NMR method was made. Growth and alginate production by A. vinelandii in batch and continuous culture were studied. Polysaccharide production was favored in batch culture by reduced aeration rates by by intermediate aeration rates in continuous culture. The partitioning of Ca/sup 45/ in solution and associated with alginates during the growth cycle of A. vinelandii was studied. The change in the composition of polysaccharide produced during growth of A. vinelandii was related to the level of free Ca/sup + +/ which fell rapidly during initial stages of incubation. The degree of acetylation of the polyuronate was shown to be variable. Production of alginates with high O-acetate contents was observed in cultures maintained at high growth rates and high Ca/sup + +/ levels. The degree of acetylation of the polyuronate was not related to the level of epimerization in vivo although in vitro studies demonstrated that chemical acetylation of the alginate inhibited epimerization. Alginate production by clinical isolates of Pseudomonas aeruginosa was shown to be unstable and no polyguluronate was isolated from cultures. It was also noted that Ca/sup + +/ played a less important role in the composition of the polysaccharide.

Expression of the Azotobacter vinelandii Poly-β-Hydroxybutyrate Biosynthetic phbBAC Operon Is Driven by Two Overlapping Promoters and Is Dependent on the Transcriptional Activator PhbR

OpenAIRE

Peralta-Gil, Martín; Segura, Daniel; Guzmán, Josefina; Servín-González, Luis; Espín, Guadalupe

2002-01-01

The Azotobacter vinelandii phbBAC genes encode the enzymes for poly-β-hydroxybutyrate (PHB) synthesis. The phbR gene, which is located upstream of and in the opposite direction of phbBAC, encodes PhbR, a transcriptional activator which is a member of the AraC family of activators. Here we report that a mutation in phbR reduced PHB accumulation and transcription of a phbB-lacZ fusion. We also report that phbB is transcribed from two overlapping promoters, pB1 and pB2. The region corresponding ...

Effects of Chemical Components on the Growth of Azotobacter vinelandii Mutant and PHB Production

International Nuclear Information System (INIS)

Nur Izzah Mohd Razak; Safiyyah Zainuddin; Ying, P.L.W.; Chyan, J.B.; Elly Ellyna Rashid

2016-01-01

Polyhydroxy butyrate (PHB) is a non-toxic biodegradable polymer produced by some bacteria and can be applied in medical, pharmacology and food industry. Eight types of chemical components acting as supplements were added to culture medium as nutrient pulses. The growth of bacteria was monitored by recording the absorbance value at 600 nm for every 24 hours of cultivation. PHB was extracted using chloroform. Reading at 235 nm was recorded to determine the PHB concentration. By observing the dry cell weight, we observed the addition of sucrose increased the biomass of Azotobacter vinelandii mutant from 1.5 mg/ mL to 5.6 mg/ mL and 8.4 mg/ mL after 3, 4 and 7 days of cultivation, respectively. The highest PHB concentration of 859.27 μg/ mL was obtained after seven days of cultivation in the medium which was supplied with urea sequentially, With sucrose, the PHB concentration increased from 25.45 μg/ ml to 99.59 μg/ ml and 655.56 μg/ ml after 3, 4 and 7 days of cultivation, respectively. The PHB concentrations obtained with sucrose-pulses were the second highest after urea. As a conclusion, sucrose and urea are the two major factors in the growth and PHB production by A. vinelandii mutant. (author)

Production of polyhydroxybutyrate and alginate from glycerol by Azotobacter vinelandii under nitrogen-free conditions.

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Yoneyama, Fuminori; Yamamoto, Mayumi; Hashimoto, Wataru; Murata, Kousaku

2015-01-01

Glycerol is an interesting feedstock for biomaterials such as biofuels and bioplastics because of its abundance as a by-product during biodiesel production. Here we demonstrate glycerol metabolism in the nitrogen-fixing species Azotobacter vinelandii through metabolomics and nitrogen-free bacterial production of biopolymers, such as poly-d-3-hydroxybutyrate (PHB) and alginate, from glycerol. Glycerol-3-phosphate was accumulated in A. vinelandii cells grown on glycerol to the exponential phase, and its level drastically decreased in the cells grown to the stationary growth phase. A. vinelandii also overexpressed the glycerol-3-phosphate dehydrogenase gene when it was grown on glycerol. These results indicate that glycerol was first converted to glycerol-3-phosphate by glycerol kinase. Other molecules with industrial interests, such as lactic acid and amino acids including γ-aminobutyric acid, have also been accumulated in the bacterial cells grown on glycerol. Transmission electron microscopy revealed that glycerol-grown A. vinelandii stored PHB within the cells. The PHB production level reached 33% per dry cell weight in nitrogen-free glycerol medium. When grown on glycerol, alginate-overproducing mutants generated through chemical mutagenesis produced 2-fold the amount of alginate from glycerol than the parental wild-type strain. To the best of our knowledge, this is the first report on bacterial production of biopolymers from glycerol without addition of any nitrogen source.

ACCUMULATION OF POLYHYDROXYALKANOIC ACIDS BY AZOTOBACTER CHROOCOCCUM MAL-201 FROM ORGANIC WASTE

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Soma Pal Saha

2013-08-01

Full Text Available Azotobacter chroococcum MAL-201 (MTCC 3853, a free-living nitrogen-fixing bacterium accumulated intracellular poly(3-hydroxybutyric acid [P(3HB] accounting 69% of cell dry weight (CDW when grown in nitrogrn-free Stockdale medium containing 2% (w/v glucose. It also produced copolymer of poly(3-hydroxybutyrate co-3-hydroxyvalerate [P(3HB-co-3HV] using glucose as primary carbon source and valerate cas cosubstrate. To make the polymer production cost effective four types of waste material of different origin were tested for growth and polymer production. Stockdale medium supplemented with 1% (w/v waste materials failed to yield good growth and polymer accumulation. Two–step cultivation was adopted for better growth and enhanced polymer accumulation. The candy factory waste was most suitable for synthesis of P(3HB accounting 17.8 and 40.58% using single and two-step cultivation conditions respectively. Wastes of domestic and poultry origin produced P(3HB-co-3HV with 3HV content 28.8 and 21.5 mol% respectively in two-step cultivation. Increase concentration of these wastes resulted in further upliftment of 3HV content of polymer with reduced growth and polymer accumulation. However, at optimum incubation the strain MAL-201 cells accumulated P(3HB 48.5% of CDW (at 40h from candy factory waste and P(3HB-co-3HV 24.75 % of CDW with 3HV 34.65 mol % from domestic waste. Intrinsic viscosity, molecular weight and thermal degradation of the polymers accumulated in the cells grown in glucose, glucose with valerate and glucose with waste were compared.

Molecular and bioengineering strategies to improve alginate and polydydroxyalkanoate production by Azotobacter vinelandii

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Espín Guadalupe

2007-02-01

Full Text Available Abstract Several aspects of alginate and PHB synthesis in Azotobacter vinelandii at a molecular level have been elucidated in articles published during the last ten years. It is now clear that alginate and PHB synthesis are under a very complex genetic control. Genetic modification of A. vinelandii has produced a number of very interesting mutants which have particular traits for alginate production. One of these mutants has been shown to produce the alginate with the highest mean molecular mass so far reported. Recent work has also shed light on the factors determining molecular mass distribution; the most important of these being identified as; dissolved oxygen tension and specific growth rate. The use of specific mutants has been very useful for the correct analysis and interpretation of the factors affecting polymerization. Recent scale-up/down work on alginate production has shown that oxygen limitation is crucial for producing alginate of high molecular mass, a condition which is optimized in shake flasks and which can now be reproduced in stirred fermenters. It is clear that the phenotypes of mutants grown on plates are not necessarily reproducible when the strains are tested in lab or bench scale fermenters. In the case of PHB, A. vinelandii has shown itself able to produce relatively large amounts of this polymer of high molecular weight on cheap substrates, even allowing for simple extraction processes. The development of fermentation strategies has also shown promising results in terms of improving productivity. The understanding of the regulatory mechanisms involved in the control of PHB synthesis, and of its metabolic relationships, has increased considerably, making way for new potential strategies for the further improvement of PHB production. Overall, the use of a multidisciplinary approach, integrating molecular and bioengineering aspects is a necessity for optimizing alginate and PHB production in A. vinelandii.

Integrated approach for disease management and growth enhancement of Sesamum indicum L. utilizing Azotobacter chroococcum TRA2 and chemical fertilizer.

Science.gov (United States)

Maheshwari, D K; Dubey, R C; Aeron, Abhinav; Kumar, Bhavesh; Kumar, Sandeep; Tewari, Sakshi; Arora, Naveen Kumar

2012-10-01

Azotobacter chroococcum TRA2, an isolate of wheat rhizosphere displayed plant growth promoting attributes including indole acetic acid, HCN, siderophore production, solubilization of inorganic phosphate and fixation of atmospheric nitrogen. In addition, it showed strong antagonistic effect against Macrophomina phaseolina and Fusarium oxysporum. It also caused degradation and digestion of cell wall components, resulting in hyphal perforations, empty cell (halo) formation, shrinking and lysis of fungal mycelia along with significant degeneration of conidia. Fertilizer adaptive variant strain of A. chroococcum TRA2 was studied with Tn5 induced streptomycin resistant transconjugants of wild type tetracycline-resistant TRA2 (designated TRA2(tetra+strep+)) after different durations. The strain was significantly competent in rhizosphere, as its population increased by 15.29 % in rhizosphere of Sesamum indicum. Seed bacterization with the strain TRA2 resulted in significant increase in vegetative growth parameters and yield of sesame over the non-bacterized seeds. However, application of TRA2 with half dose of fertilizers showed sesame yield almost similar to that obtained by full dose treatment. Moreover, the oil yield increased by 24.20 %, while protein yield increased by 35.92 % in treatment receiving half dose of fertilizer along with TRA2 bacterized seeds, as compared to untreated control.

Gene Deletions Resulting in Increased Nitrogen Release by Azotobacter vinelandii: Application of a Novel Nitrogen Biosensor

Science.gov (United States)

Eberhart, Lauren J.; Ohlert, Janet M.; Knutson, Carolann M.; Plunkett, Mary H.

2015-01-01

Azotobacter vinelandii is a widely studied model diazotrophic (nitrogen-fixing) bacterium and also an obligate aerobe, differentiating it from many other diazotrophs that require environments low in oxygen for the function of the nitrogenase. As a free-living bacterium, A. vinelandii has evolved enzymes and transporters to minimize the loss of fixed nitrogen to the surrounding environment. In this study, we pursued efforts to target specific enzymes and further developed screens to identify individual colonies of A. vinelandii producing elevated levels of extracellular nitrogen. Targeted deletions were done to convert urea into a terminal product by disrupting the urease genes that influence the ability of A. vinelandii to recycle the urea nitrogen within the cell. Construction of a nitrogen biosensor strain was done to rapidly screen several thousand colonies disrupted by transposon insertional mutagenesis to identify strains with increased extracellular nitrogen production. Several disruptions were identified in the ammonium transporter gene amtB that resulted in the production of sufficient levels of extracellular nitrogen to support the growth of the biosensor strain. Further studies substituting the biosensor strain with the green alga Chlorella sorokiniana confirmed that levels of nitrogen produced were sufficient to support the growth of this organism when the medium was supplemented with sufficient sucrose to support the growth of the A. vinelandii in coculture. The nature and quantities of nitrogen released by urease and amtB disruptions were further compared to strains reported in previous efforts that altered the nifLA regulatory system to produce elevated levels of ammonium. These results reveal alternative approaches that can be used in various combinations to yield new strains that might have further application in biofertilizer schemes. PMID:25888177

Azotobacter chroococcum as a potentially useful bacterial biofertilizer for cotton (Gossypium hirsutum): Effect in reducing N fertilization.

Science.gov (United States)

Romero-Perdomo, Felipe; Abril, Jorge; Camelo, Mauricio; Moreno-Galván, Andrés; Pastrana, Iván; Rojas-Tapias, Daniel; Bonilla, Ruth

The aim of this research was to evaluate whether the application of two plant growth-promoting (rhizo)bacteria might reduce nitrogen fertilization doses in cotton. We used strains Azotobacter chroococcum AC1 and AC10 for their proven ability to promote seed germination and cotton growth. These microorganisms were characterized by their plant growth-promoting activities. Then, we conducted a glasshouse study to evaluate the plant growth promoting ability of these strains with reduced doses of urea fertilization in cotton. Results revealed that both strains are capable of fixing nitrogen, solubilizing phosphorus, synthesizing indole compounds and producing hydrolytic enzymes. After 12 weeks, the glasshouse experiment showed that cotton growth was positively influenced due to bacterial inoculation with respect to chemical fertilization. Notably, we observed that microbial inoculation further influenced plant biomass (p<0.05) than nitrogen content. Co-inoculation, interestingly, exhibited a greater beneficial effect on plant growth parameters compared to single inoculation. Moreover, similar results without significant statistical differences were observed among bacterial co-inoculation plus 50% urea and 100% fertilization. These findings suggest that co-inoculation of A. chroococcum strains allow to reduce nitrogen fertilization doses up to 50% on cotton growth. Our results showed that inoculation with AC1 and AC10 represents a viable alternative to improve cotton growth while decreasing the N fertilizer dose and allows to alleviate the environmental deterioration related to N pollution. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Spectroscopic and functional characterization of iron-bound forms of Azotobacter vinelandii (Nif)IscA.

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Mapolelo, Daphne T; Zhang, Bo; Naik, Sunil G; Huynh, Boi Hanh; Johnson, Michael K

2012-10-16

The ability of Azotobacter vinelandii(Nif)IscA to bind Fe has been investigated to assess the role of Fe-bound forms in NIF-specific Fe-S cluster biogenesis. (Nif)IscA is shown to bind one Fe(III) or one Fe(II) per homodimer and the spectroscopic and redox properties of both the Fe(III)- and Fe(II)-bound forms have been characterized using the UV-visible absorption, circular dichroism, and variable-temperature magnetic circular dichroism, electron paramagnetic resonance, Mössbauer and resonance Raman spectroscopies. The results reveal a rhombic intermediate-spin (S = 3/2) Fe(III) center (E/D = 0.33, D = 3.5 ± 1.5 cm(-1)) that is most likely 5-coordinate with two or three cysteinate ligands and a rhombic high spin (S = 2) Fe(II) center (E/D = 0.28, D = 7.6 cm(-1)) with properties similar to reduced rubredoxins or rubredoxin variants with three cysteinate and one or two oxygenic ligands. Iron-bound (Nif)IscA undergoes reversible redox cycling between the Fe(III)/Fe(II) forms with a midpoint potential of +36 ± 15 mV at pH 7.8 (versus NHE). l-Cysteine is effective in mediating release of free Fe(II) from both the Fe(II)- and Fe(III)-bound forms of (Nif)IscA. Fe(III)-bound (Nif)IscA was also shown to be a competent iron source for in vitro NifS-mediated [2Fe-2S] cluster assembly on the N-terminal domain of NifU, but the reaction occurs via cysteine-mediated release of free Fe(II) rather than direct iron transfer. The proposed roles of A-type proteins in storing Fe under aerobic growth conditions and serving as iron donors for cluster assembly on U-type scaffold proteins or maturation of biological [4Fe-4S] centers are discussed in light of these results.

Preparation of Biocomposites using Sawdust and Lignosulfonate with a Culturе Liquid of Levan Producer Azotobacter vinelandii as a Bonding Agent

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Victor V. Revin

2016-02-01

Full Text Available The possibility of preparing molding-bioengineered materials, such as woodchip boards (WCB, from sawdust using technical lignosulfonate (LGS, a wood waste product, and a culture liquid (CL of levan microbial polysaccharide producer by Azotobacter vinelandii D-08 is explored in this article. The parameters of the derived materials are comparable to those of traditional materials made from toxic phenol-formaldehyde resins. The various physical and mechanical characteristics of the materials depend on the quantity of the bonding agent used for the preparation. Adding a culture liquid increases the humidity resistance of the molding materials. Using electron microscopy and X-ray micro-tomography, it is clear that the structure of woodchip boards become more homogeneous without microcracks with the addition of CL. The strength of the best samples prepared was approximately 24 to 29 MPa with a density of 1170 to 1255 kg/m3 and a swell on wetting of 6.7%. During hot pressing, noticeable changes were observed by Fourier transform infrared spectroscopy (FTIR at frequencies typical of LGS sulfonic-acid groups, levan fructose fragments, and skeletal vibrations of a syringal/guaiacyl core in lignin and of C-H groups of hemicelluloses. This indicates the involvement of these functional groups in the process of binding wood particles with hot pressing.

A metodologia de superfície de resposta como ferramenta para a avaliação da produção de alginato e poli-hidroxibutirato pela Azotobacter vinelandii = The response surface methodology as a tool for assessing the production of alginate and polyhydroxybutirate by Azotobacter vinelandii

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Adriana Navarro da Silva

2010-07-01

Full Text Available O alginato é um polissacarídeo normalmente extraído de paredes celulares de algas marrons e utilizado nas indústrias de alimentos, farmacêuticas e biotecnológicas. A produção é concentrada no cultivo de algas marinhas marrons, mas várias bactérias do gênero Pseudomonas e Azotobacter produzem alginato. A estrutura química dos alginatosproduzidos por algas é similar a dos sintetizados pela A. vinelandii. Esta bactéria também produz polímeros intracelulares como o poli-hidroxibutirato (PHB, conhecido como bioplástico. Neste trabalho, estudou-se a produção simultânea do alginato e PHB pela A.vinelandii, utilizando-se sacarose e diferentes parâmetros de fermentação em agitador orbital rotatório. Os valores ótimos para produção destes compostos foram determinados pela MSR. O 1º experimento foi um planejamento fatorial fracionado 26-2. O 2º foi baseado nas variáveis significativas do 1º experimento, resultando em um planejamento fatorial completo 33-0. Verificou-se, do primeiro para o segundo, aumento na produtividade do PHB de 12 para 45 mg g-1 de célula h-1 e do alginato de 100 para 1.600 mg g-1 de célula h-1. Aprodutividade de ambos os compostos foi máxima na temperatura de incubação de 62ºC, no menor tempo de incubação (18h e na concentração de sacarose de 11 g L-1. Em ambos os experimentos, o PHB extraído apresentou pureza de 94%.Alginate is a polysaccharide extracted from cell walls of brown algae and used in the food, pharmaceuticals and biotech industries. Production is concentrated on the cultivation of brown seaweed, but several bacteria of the genus Pseudomonas and Azotobacter producealginate. The chemical structure of alginates produced by algae is similar to those synthesized by A. vinelandii. The bacteria also produce intracellular polymers such as polyhydroxybutyrate (PHB, known as bioplastic. This work studied the simultaneous alginate and PHB production by A. vinelandii using sucrose and

Effects of tungsten and titanium oxide nanoparticles on the diazotrophic growth and metals acquisition by Azotobacter vinelandii under molybdenum limiting condition.

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Allard, Patrick; Darnajoux, Romain; Phalyvong, Karine; Bellenger, Jean-Philippe

2013-02-19

The acquisition of essential metals, such as the metal cofactors (molybdenum (Mo) and iron (Fe)) of the nitrogenase, the enzyme responsible for the reduction of dinitrogen (N(2)) to ammonium, is critical to N(2) fixing bacteria in soil. The release of metal nanoparticles (MNPs) to the environment could be detrimental to N(2) fixing bacteria by introducing a new source of toxic metals and by interfering with the acquisition of essential metals such as Mo. Since Mo has been reported to limit nonsymbiotic N(2) fixation in many ecosystems from tropical to cold temperate, this question is particularly acute in the context of Mo limitation. Using a combination of microbiology and analytical chemistry techniques, we have evaluated the effect of titanium (Ti) and tungsten (W) oxide nanoparticles on the diazotrophic growth and metals acquisition in pure culture of the ubiquitous N(2) fixing bacterium Azotobacter vinelandii under Mo replete and Mo limiting conditions. We report that under our conditions (≤10 mg·L(-1)) TiO(2) NPs have no effects on the diazotrophic growth of A. vinelandii while WO(3) NPs are highly detrimental to the growth especially under Mo limiting conditions. Our results show that the toxicity of WO(3) NPs to A. vinelandii is due to an interference with the catechol-metalophores assisted uptake of Mo.

Modeling and Re-Engineering of Azotobacter vinelandii Alginate Lyase to Enhance Its Catalytic Efficiency for Accelerating Biofilm Degradation.

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Jang, Chul Ho; Piao, Yu Lan; Huang, Xiaoqin; Yoon, Eun Jeong; Park, So Hee; Lee, Kyoung; Zhan, Chang-Guo; Cho, Hoon

2016-01-01

Alginate is known to prevent elimination of Pseudomonas aeruginosa biofilms. Alginate lyase (AlgL) might therefore facilitate treatment of Pseudomonas aeruginosa-infected cystic fibrosis patients. However, the catalytic activity of wild-type AlgL is not sufficiently high. Therefore, molecular modeling and site-directed mutagenesis of AlgL might assist in enzyme engineering for therapeutic development. AlgL, isolated from Azotobacter vinelandii, catalyzes depolymerization of alginate via a β-elimination reaction. AlgL was modeled based on the crystal structure template of Sphingomonas AlgL species A1-III. Based on this computational analysis, AlgL was subjected to site-directed mutagenesis to improve its catalytic activity. The kcat/Km of the K194E mutant showed a nearly 5-fold increase against the acetylated alginate substrate, as compared to the wild-type. Double and triple mutants (K194E/K245D, K245D/K319A, K194E/K245D/E312D, and K194E/K245D/K319A) were also prepared. The most potent mutant was observed to be K194E/K245D/K319A, which has a 10-fold improved kcat value (against acetylated alginate) compared to the wild-type enzyme. The antibiofilm effect of both AlgL forms was identified in combination with piperacillin/tazobactam (PT) and the disruption effect was significantly higher in mutant AlgL combined with PT than wild-type AlgL. However, for both the wild-type and K194E/K245D/K319A mutant, the use of the AlgL enzyme alone did not show significant antibiofilm effect.

Modeling and Re-Engineering of Azotobacter vinelandii Alginate Lyase to Enhance Its Catalytic Efficiency for Accelerating Biofilm Degradation.

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Chul Ho Jang

Full Text Available Alginate is known to prevent elimination of Pseudomonas aeruginosa biofilms. Alginate lyase (AlgL might therefore facilitate treatment of Pseudomonas aeruginosa-infected cystic fibrosis patients. However, the catalytic activity of wild-type AlgL is not sufficiently high. Therefore, molecular modeling and site-directed mutagenesis of AlgL might assist in enzyme engineering for therapeutic development. AlgL, isolated from Azotobacter vinelandii, catalyzes depolymerization of alginate via a β-elimination reaction. AlgL was modeled based on the crystal structure template of Sphingomonas AlgL species A1-III. Based on this computational analysis, AlgL was subjected to site-directed mutagenesis to improve its catalytic activity. The kcat/Km of the K194E mutant showed a nearly 5-fold increase against the acetylated alginate substrate, as compared to the wild-type. Double and triple mutants (K194E/K245D, K245D/K319A, K194E/K245D/E312D, and K194E/K245D/K319A were also prepared. The most potent mutant was observed to be K194E/K245D/K319A, which has a 10-fold improved kcat value (against acetylated alginate compared to the wild-type enzyme. The antibiofilm effect of both AlgL forms was identified in combination with piperacillin/tazobactam (PT and the disruption effect was significantly higher in mutant AlgL combined with PT than wild-type AlgL. However, for both the wild-type and K194E/K245D/K319A mutant, the use of the AlgL enzyme alone did not show significant antibiofilm effect.

Spectroscopic and functional characterization of iron-sulfur cluster-bound forms of Azotobacter vinelandii (Nif)IscA.

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Mapolelo, Daphne T; Zhang, Bo; Naik, Sunil G; Huynh, Boi Hanh; Johnson, Michael K

2012-10-16

The mechanism of [4Fe-4S] cluster assembly on A-type Fe-S cluster assembly proteins, in general, and the specific role of (Nif)IscA in the maturation of nitrogen fixation proteins are currently unknown. To address these questions, in vitro spectroscopic studies (UV-visible absorption/CD, resonance Raman and Mössbauer) have been used to investigate the mechanism of [4Fe-4S] cluster assembly on Azotobacter vinelandii(Nif)IscA, and the ability of (Nif)IscA to accept clusters from NifU and to donate clusters to the apo form of the nitrogenase Fe-protein. The results show that (Nif)IscA can rapidly and reversibly cycle between forms containing one [2Fe-2S](2+) and one [4Fe-4S](2+) cluster per homodimer via DTT-induced two-electron reductive coupling of two [2Fe-2S](2+) clusters and O(2)-induced [4Fe-4S](2+) oxidative cleavage. This unique type of cluster interconversion in response to cellular redox status and oxygen levels is likely to be important for the specific role of A-type proteins in the maturation of [4Fe-4S] cluster-containing proteins under aerobic growth or oxidative stress conditions. Only the [4Fe-4S](2+)-(Nif)IscA was competent for rapid activation of apo-nitrogenase Fe protein under anaerobic conditions. Apo-(Nif)IscA was shown to accept clusters from [4Fe-4S] cluster-bound NifU via rapid intact cluster transfer, indicating a potential role as a cluster carrier for delivery of clusters assembled on NifU. Overall the results support the proposal that A-type proteins can function as carrier proteins for clusters assembled on U-type proteins and suggest that they are likely to supply [2Fe-2S] clusters rather than [4Fe-4S] for the maturation of [4Fe-4S] cluster-containing proteins under aerobic or oxidative stress growth conditions.

Iron environment in ferritin with large amounts of phosphate, from Azotobacter vinelandii and horse spleen, analyzed using Extended X-ray Absorption fine Structure (EXAFS)

International Nuclear Information System (INIS)

Rohrer, J.S.; Islam, Q.T.; Sayes, D.E.; Theil, E.C.; Watt, G.D.

1990-01-01

The iron core of proteins in the ferritin family displays structural variations that includes phosphate content was well as the number and the degree of ordering of the iron atoms. Earlier studies had shown that ferritin iron cores naturally high in phosphate, e.g., Azotobacter vinelandii (AV) ferritin had decreased long-range order. Here, the influence of phosphate on the local structure around iron in ferritin cores is reported, comparing the EXAFS of AV ferritin, reconstituted ferritin and native horse spleen ferritin. In contrast, when the phosphate content was high in AV ferritin and horse spleen ferritin reconstituted with phosphate, the average iron atom had five to six phosphorus neighbors at 3.17 angstrom. Moreover, the number of detectable iron neighbors was lower when phosphate was high or present during reconstitution and the interatomic distance was longer indicating that some phosphate bridges neighboring iron atoms. However, the decrease in the number of detectable iron-iron neighbors compared to HSF and the higher number of Fe-P interactions relative to Fe-Fe interactions suggest that some phosphate ligands were chain termini, or blocked crystal growth, and/or introduced defects which contributed both to the long-range disorder and to altered redox properties previously observed in AV ferritin

Rapid Biosynthesis of AgNPs Using Soil Bacterium Azotobacter vinelandii With Promising Antioxidant and Antibacterial Activities for Biomedical Applications

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Karunakaran, Gopalu; Jagathambal, Matheswaran; Gusev, Alexander; Torres, Juan Antonio Lopez; Kolesnikov, Evgeny; Kuznetsov, Denis

2017-07-01

Silver nanoparticles (AgNPs) are applied in various fields from electronics to biomedical applications as a result of their high surface-to-volume ratio. Even though different approaches are available for synthesis of AgNPs, a nontoxic method for the synthesis has not yet been developed. Thus, this study focused on developing an easy and ecofriendly approach to synthesize AgNPs using Azotobacter vinelandii culture extracts. The biosynthesized nanoparticles were further characterized by ultraviolet-visible (UV-Vis) spectroscopy, x-ray diffraction (XRD), Fourier transform infrared (FTIR), energy-dispersive spectrum, particle size distribution (PSD), and transmission electron microscopy (TEM). UV absorption noticed at 435 nm showed formation of AgNPs. The XRD pattern showed a face-centered cubic structure with broad peaks of 28.2°, 32.6°, 46.6°, 55.2°, 57.9°, and 67.8°. The FTIR confirmed the involvement of various functional groups in the biosynthesis of AgNPs. The PSD and TEM analyses showed spherical, well-distributed nanoparticles with an average size of 20-70 nm. The elemental studies confirmed the existence of pure AgNPs. The bacterial extract containing extracellular enzyme nitrate reductase converted silver nitrate into AgNPs. AgNPs significantly inhibited the growth of pathogenic bacteria such as Streptomyces fradiae (National Collection of Industrial Microorganisms (NCIM) 2419), Staphylococcus aureus (NCIM 2127), Escherichia coli (NCIM 2065), and Serratia marcescens (NCIM 2919). In addition, biosynthesized AgNPs were found to possess strong antioxidant activity. Thus, the results of this study revealed that biosynthesized AgNPs could serve as a lead in the development of nanomedicine.

Ligand size is a major determinant of specificity in periplasmic oxyanion-binding proteins: the 1.2 A resolution crystal structure of Azotobacter vinelandii ModA.

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Lawson, D M; Williams, C E; Mitchenall, L A; Pau, R N

1998-12-15

. Periplasmic receptors constitute a diverse class of binding proteins that differ widely in size, sequence and ligand specificity. Nevertheless, almost all of them display a common beta/alpha folding motif and have similar tertiary structures consisting of two globular domains. The ligand is bound at the bottom of a deep cleft, which lies at the interface between these two domains. The oxyanion-binding proteins are notable in that they can discriminate between very similar ligands. . Azotobacter vinelandii is unusual in that it possesses two periplasmic molybdate-binding proteins. The crystal structure of one of these with bound ligand has been determined at 1.2 A resolution. It superficially resembles the structure of sulphate-binding protein (SBP) from Salmonella typhimurium and uses a similar constellation of hydrogen-bonding interactions to bind its ligand. However, the detailed interactions are distinct from those of SBP and the more closely related molybdate-binding protein of Escherichia coli. . Despite differences in the residues involved in binding, the volumes of the binding pockets in the A. vinelandii and E. coli molybdate-binding proteins are similar and are significantly larger than that of SBP. We conclude that the discrimination between molybdate and sulphate shown by these binding proteins is largely dependent upon small differences in the sizes of these two oxyanions.

Optimization of Medium Components for Cell Biomass and Polyhydroxy Butyric Acid Production by Azotobacter vinelandii Mutant Using Response Surface Methodology

International Nuclear Information System (INIS)

Safiyyah Zainuddin; Nur Izzah Mohd Razak; Ying, P.L.W.; Chyan, J.B.; Elly Ellyna Rashid

2016-01-01

Polyhydroxy butyric acid (PHB) is a biodegradable and food-safe alternative to petroleum-based polymers. Using RSM approach, the interaction of sucrose, urea and K_2HPO_4 were investigated to determine the optimum medium compositions for cell biomass and PHB production by Azotobacter vinelandii mutant. Fifteen medium types were prepared and each contained different amount of sucrose, urea and K_2HPO_4. Analyses of cell biomass and PHB concentration were performed from day-2 until day-4 (3 days). Based on the biomass analysis, Medium 13 achieved the highest cell dry weight of 15.4 mg/ mL on day-3. Medium 13 contained 0.5 g/ L of urea, 0.1 g/ L of K_2HPO_4 and 10 g/ L of sucrose. For PHB production, Medium 11 achieved the highest PHB production on day-3 (3.7 mg/ mL) and dropped to 1.3 mg/ mL on day-4. Sample 11 contained 0.5 g/ L of urea, 0 g/ L of K_2HPO_4 and 20 g/ L of sucrose. Sample 2 (1.0 g/ L urea, 0.05 g/ L K_2HPO_4 and 15 g/ L sucrose) and 6 (1.0 g/ L urea, 0.05 g/ L K_2HPO_4 and 25 g/ L sucrose) showed PHB production of >2.0 mg/ mL on day-3 and persisted to day-4. Sample 3 (0.25 g/ L urea, 0.2 g/ L K_2HPO_4 and 15 g/L sucrose) achieved PHB production of >2.0 mg/mL only on day-4. All the other medium types showed PHB production of lower than 1.5 mg/ mL throughout the experiment. (author)

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

African Journals Online (AJOL)

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

NCBI nr-aa BLAST: CBRC-XTRO-01-0305 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-XTRO-01-0305 ref|ZP_00419399.1| Heavy metal efflux pump CzcA [Azotobacter vine...landii AvOP] gb|EAM04226.1| Heavy metal efflux pump CzcA [Azotobacter vinelandii AvOP] ZP_00419399.1 0.0 77% ...

Glucose uptake in Azotobacter vinelandii occurs through a GluP transporter that is under the control of the CbrA/CbrB and Hfq-Crc systems.

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Quiroz-Rocha, Elva; Moreno, Renata; Hernández-Ortíz, Armando; Fragoso-Jiménez, Juan Carlos; Muriel-Millán, Luis Felipe; Guzmán, Josefina; Espín, Guadalupe; Rojo, Fernando; Núñez, Cinthia

2017-04-12

Azotobacter vinelandii, a strict aerobic, nitrogen fixing bacterium in the Pseudomonadaceae family, exhibits a preferential use of acetate over glucose as a carbon source. In this study, we show that GluP (Avin04150), annotated as an H + -coupled glucose-galactose symporter, is the glucose transporter in A. vinelandii. This protein, which is widely distributed in bacteria and archaea, is uncommon in Pseudomonas species. We found that expression of gluP was under catabolite repression control thorugh the CbrA/CbrB and Crc/Hfq regulatory systems, which were functionally conserved between A. vinelandii and Pseudomonas species. While the histidine kinase CbrA was essential for glucose utilization, over-expression of the Crc protein arrested cell growth when glucose was the sole carbon source. Crc and Hfq proteins from either A. vinelandii or P. putida could form a stable complex with an RNA A-rich Hfq-binding motif present in the leader region of gluP mRNA. Moreover, in P. putida, the gluP A-rich Hfq-binding motif was functional and promoted translational inhibition of a lacZ reporter gene. The fact that gluP is not widely distributed in the Pseudomonas genus but is under control of the CbrA/CbrB and Crc/Hfq systems demonstrates the relevance of these systems in regulating metabolism in the Pseudomonadaceae family.

Growth of Azotobacter vinelandii UWD in Fish Peptone Medium and Simplified Extraction of Poly-β-Hydroxybutyrate

Science.gov (United States)

Page, William J.; Cornish, Anthony

1993-01-01

Azotobacter vinelandii UWD was grown in a fermentor with glucose medium with and without 0.1% fish peptone (FP) in batch and fed-batch cultures for the production of the natural bioplastic poly-β-hydroxybutyrate (PHB). Strain UWD formed PHB five times faster than cell protein during growth in glucose and NH4+, but PHB synthesis stopped when NH4+ was depleted and nitrogen fixation started. When FP was added to the same medium, PHB accumulated 16 times faster than cell protein, which in turn was inhibited by 40%, and PHB synthesis was unaffected by NH4+ depletion. Thus, FP appeared to be used as a nitrogen source by these nitrogen-fixing cells, which permitted enhanced PHB synthesis, but it was not a general growth stimulator. The addition of FP to the medium led to the production of large, pleomorphic, osmotically sensitive cells that demonstrated impaired growth and partial lysis, with the leakage of DNA into the culture fluid, but these cells were still able to synthesize PHB at elevated rates and efficiency. When FP was continuously present in fed-batch culture, the yield in grams of polymer per gram of glucose consumed was calculated to range from 0.43 g/g, characteristic of nongrowing cells, to an unprecedented 0.65 g/g. Separation of an FP-free growth phase from an FP-containing growth phase in fed-batch culture resulted in better growth of these pleomorphic cells and good production of PHB (yield, 0.32 g/g). The fragility of these cells was exploited in a simple procedure for the extraction of high-molecular-weight PHB. The cells were treated with 1 N aqueous NH3 (pH 11.4) at 45°C for 10 min. This treatment removed about 10% of the non-PHB mass from the pellet, of which 60 to 77% was protein. The final product consisted of 94% PHB, 2% protein, and 4% nonprotein residual mass. The polymer molecular weight (1.7 × 106 to 2.0 × 106) and dispersity (1.0 to 1.9) were not significantly affected (P = 0.05) by this treatment. In addition, the NH3 extraction waste

Viability of HEK 293 cells on poly-β-hydroxybutyrate (PHB) biosynthesized from a mutant Azotobacter vinelandii strain. Cast film and electrospun scaffolds.

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Romo-Uribe, Angel; Meneses-Acosta, Angelica; Domínguez-Díaz, Maraolina

2017-12-01

Sterilization, cytotoxicity and cell viability are essential properties defining a material for medical applications and these characteristics were investigated for poly(β-hydroxybutyrate) (PHB) of 230kDa obtained by bacterial synthesis from a mutant strain of Azotobacter vinelandii. Cell viability was investigated for two types of PHB scaffolds, solution cast films and non-woven electrospun fibrous membranes, and the efficiency was compared against a culture dish. The biosynthesized PHB was sterilized by ultraviolet radiation and autoclave, it was found that the thermal properties and intrinsic viscosity remained unchanged indicating that the sterilization methods did not degrade the polymer. Sterilized scaffolds were then seeded with human embryonic kidney 293 (HEK 293) cells to evaluate the cytotoxic response. The cell viability of these cells was evaluated for up to six days, and the results showed that the cell morphology was normal, with no cytotoxic effects. The films and electrospun membranes exhibited over 95% cell viability whereas the viability in culture dishes reached only ca. 90%. The electrospun membrane, however, exhibited significantly higher cell density than the cast film suggesting that the fibrous morphology enables better nutrients transfer. The results indicate that the biosynthesized PHB stands UV and autoclave sterilization methods, it is biocompatible and non-toxic for cell growth of human cell lines. Furthermore, cell culture for up to 18 days showed that 62% and 90% of mass was lost for the film and fibrous electrospun scaffold, respectively. This is a favorable outcome for use in tissue engineering where material degradation, as tissue regenerates, is desirable. Copyright © 2017 Elsevier B.V. All rights reserved.

Mobile sequences in the pyruvate dehydrogenase complex, the E2 component, the catalytic domain and the 2-oxogluturate dehydrogenase complex of Azotobacter vinelandii, as detected by 600 MHz 1H-NMR spectroscopy

International Nuclear Information System (INIS)

Hanemaaijer, R.; Vervoort, J.; Westphal, A.H.; Kok, A. de.; Veeger, C.

1988-01-01

600 MHz 1 H-NMR spectroscopy demonstrates that the pyruvate dehydrogenase complex of Azotobacter vinelandii contains regions of the polypeptide chain with intramolecular mobility. This mobility is located in the E 2 component and can probably be ascribed to alanine-proline-rich regions that link the lipoyl sibdiomains to each other as well as to the E 1 and E 3 binding domain. In the catalytic domain of E 2 which is thought to form a compact, rigid core, also conformational flexibility is observed. It is conceivable that the N-terminal region of the catalytic domain, which contains many alanine residues, is responsible for the observed mobility. In the low-field region of the 1 H-NMR spectrum of E 2 specific resonances are found, which can be ascribed to mobile phenylalanine, histidine and/or tyrosine residues which are located in the E 1 and E 3 binding domain that links the lipoyl domain to the catalytic domain. In the 1 H-NMR spectrum of the intact complex, these resonances cannot be observed, indicating a decreased mobility of the E 1 and E 3 binding domain. (author). 24 refs.; 2 figs

The production, molecular weight and viscosifying power of alginate produced by Azotobacter vinelandii is affected by the carbon source in submerged cultures

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Mauricio A. Trujillo-Roldán

2015-01-01

Full Text Available El alginato es un polímero lineal compuesto por ácidos 1,4 manurónico y su epímero, -L- gulurónico y con frecuencia se extrae de algas marinas, como también de bacterias como Azotobacter y Pseudomonas. En este trabajo, se presenta el impacto de diferentes fuentes de carbono convencionales y no convencionales en el crecimiento de A. vinelandii, producción de alginato, su peso molecular promedio (PMP y su capacidad viscosificante. Todos los experimentos se iniciaron con 20 g/L de azúcares totales, donde la más alta concentración de biomasa se obtuvo utilizando suero de leche hidrolizado y desproteinizado (6.67±0.72 g/L, y jugo de caña de azúcar (6.68±0.45 g/L. Sin embargo, la producción máxima de alginato se logró utilizando sacarosa (5.11±0.37 g/L, así como el más alto rendimiento de alginato y productividad específica. Por otra parte, el mayor PMP de alginato se obtuvo con jugo de caña de azúcar (1203±120 kDa. Además, la capacidad viscosificante más alta se obtuvo utilizando suero de leche desproteinizado e hidrolizado (23.8±2.6 cpsL/galg. Esta información sugiere que es posible manipular la productividad y las características moleculares de alginatos como función de la fuente de carbono utilizada. En conjunto con el conocimiento de los efectos de las condiciones ambientales se lograrían altos rendimientos de biopolímeros de alto valor agregado.

Plant growth promotion rhizobacteria in onion production.

Science.gov (United States)

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

2014-01-01

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

Evaluación de la asociación bacterias fijadoras de nitrógeno - líneas interespecíficas de arroz-nitrógeno, en Typic haplustalf. Ibagué, Colombia Evaluation of the association nitrogen fixing bacterias interspecific - rice lines - nitrogen, in typic haplustalf. Ibagué, Colombia

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Margarita M Vallejo

2008-01-01

Full Text Available El estudio se llevó a cabo en la hacienda Cauchitos, municipio de Ibagué, departamento del Tolima (Norte 4° 23' 51" y Oeste 75° 9' 7", 979 msnm, 24.3°C, bosque seco tropical (bs-T, con el objetivo de evaluar las asociaciones entre bacterias fijadoras de nitrógeno con inóculo y sin él en diez líneas interespecíficas de arroz, con tres dosis de nitrógeno (0%, 50% y 100% de 250 kg/ha-1 y tres repeticiones por tratamiento. La inoculación se realizó con 1 cm³ de unidades formadoras de colonias por 250 g de semilla de cada cultivar. Se aislaron 2.260 bacterias de los géneros Azotobacter spp y Azospirillum spp, se identificaron las especies A. brasilense, A. lipoferum, A. amazonense y del género Azotobacter las especies A. chroococcum, A. vinelandii, A. paspali y A. beijerinckii. Respecto al inóculo no se encontraron diferencias significativas al realizar su aplicación, se determinó que Azotobacter spp y Azospirillum spp fueron géneros típicos de la flora bacteriana en el cultivo del arroz y en condiciones de campo hubo efecto de los tratamientos en la flora bacteriana, y Azotobacter spp fue el predominante en cada uno de los tratamientos.The study was carried out at the Cauchitos farm, Ibague municipality department of Tolima, with bounds: North 4°23'51" and west 75°9'7", 979 ansm, the average temperature is 24,3°C, tropical dry forest (bs-t in the Holdridge classification. The purpose of this study was to evaluate the association between the nitrogen fixation bacteries with and without inoculo in 10 interespecific rice lines with three nitrogen dosis (0, 50 and 100% de 250 kg/ ha-1 and three repetitions. The inoculation was realized with 10(8 former units of colonies per millimeter. 2.260 bacteries of the generums Azotobacter spp y Azospirrillum spp., and identification the species: Azospirillum brasilense, Azospirillum lipoferum, Azospirillum amazonense, were identified and from the genus Azotobacter were identified the

EFECTO DE LA INOCULACIÓN DE azotobacter chroococcum Y glomus intraradices EN EL CRECIMIENTO Y NUTRICIÓN DE PLÁNTULAS DE PAPAYA EN FASE DE VIVERO

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Maricela Constantino

2011-01-01

Full Text Available En el presente estudio se evaluó la etapa y el número de aplicaciones de los biofertilizantes (Azotobacter chroococcum y Glomus intraradices, sobre el crecimiento, biomasa y nutrición de papaya en fase de vivero. También se estudió el efecto de la materia orgánica y su interacción con los biofertilizantes aplicados. Se realizaron 2 experimentos; en el primero se aplicaron 2 inoculaciones, en semillas y después en plántulas, 30 días después de la emergencia. En el segundo se aplicó una inoculación simple en plántulas, 30 días después de la emergencia. Estos experimentos se realizaron utilizando un diseño factorial 5x4 (5 tipos de sustratos x 4 tipos de biofertilizantes. Todos los tratamientos fueron aplicados como inoculantes simples o combinados (A. chroococcum y G. intraradices para un total de 20 tratamientos, con un diseño completamente al azar. La doble inoculación (semilla y plántula promovió un mayor crecimiento y biomasa en el cultivo, en comparación con la inoculación simple (solo en plántulas, cuando se adicionó una dosis intermedia de materia orgánica (25 a 35% y se aplicó G. intraradices como simple inoculante. Sin embargo, la inoculación simple o combinada no modificó el contenido de nutrientes en las plántulas de papaya.

The GacS/A-RsmA Signal Transduction Pathway Controls the Synthesis of Alkylresorcinol Lipids that Replace Membrane Phospholipids during Encystment of Azotobacter vinelandii SW136.

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Yanet Romero

Full Text Available Azotobacter vinelandii is a soil bacterium that undergoes a differentiation process that forms cysts resistant to desiccation. During encystment, a family of alkylresorcinols lipids (ARs are synthesized and become part of the membrane and are also components of the outer layer covering the cyst, where they play a structural role. The synthesis of ARs in A. vinelandii has been shown to occur by the activity of enzymes encoded in the arsABCD operon. The expression of this operon is activated by ArpR, a LysR-type transcriptional regulator whose transcription occurs during encystment and is dependent on the alternative sigma factor RpoS. In this study, we show that the two component response regulator GacA, the small RNA RsmZ1 and the translational repressor protein RsmA, implicated in the control of the synthesis of other cysts components (i.e., alginate and poly-ß-hydroxybutyrate, are also controlling alkylresorcinol synthesis. This control affects the expression of arsABCD and is exerted through the regulation of arpR expression. We show that RsmA negatively regulates arpR expression by binding its mRNA, repressing its translation. GacA in turn, positively regulates arpR expression through the activation of transcription of RsmZ1, that binds RsmA, counteracting its repressor activity. This regulatory cascade is independent of RpoS. We also show evidence suggesting that GacA exerts an additional regulation on arsABCD expression through an ArpR independent route.

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

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Nosheen, A.; Bano, A.

2014-01-01

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

Enhancement of Cotton Stalks Composting with Certain Microbial Inoculations

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Osama Abdel-Twab Seoudi

2013-01-01

Full Text Available Effect of inoculation with Phanerochaete chrysosporium and Azotobacter chrococcum microbes on cotton stalks composting was studied in an attempt to achieve rapid maturity and desirable characteristics of produced compost. Composting process was maintained for 16 weeks under aerobic conditions with proper moisture content and turning piles. The C/N ratio of the mixtures was adjusted to about 30:1 before composting using chicken manure. Temperature evolution and its profile were monitored throughout the composting period. Mineralization rates of organic matter and changes in nitrogen content during composting stages were evaluated. Total plate count of mesophilic and thermophilic bacteria, cellulose decomposers and Azotobacter were determined during composting periods. The treatment of cotton stalks inoculated with both P. chrysosporium and Azotobacter gave the most desirable characteristics of the final product with respect to the narrow C/N ratio, high nitrogen content and high numbers of Azotobacter. The phytotoxicity test of compost extracts was evaluated. The use of P. chrysosporium in composting accelerated markedly decomposition process, so that 16 weeks composting enough to produce a stable and mature compost suitable for use as fertilizer while the fertilizer obtained by composting cotton stalks mixed with chicken manure and inoculated with microorganisms is highest quality Compost.

Functional NifD-K fusion protein in Azotobacter vinelandii is a homodimeric complex equivalent to the native heterotetrameric MoFe protein

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Lahiri, Surobhi; Pulakat, Lakshmi; Gavini, Nara

2005-01-01

The MoFe protein of the complex metalloenzyme nitrogenase folds as a heterotetramer containing two copies each of the homologous α and β subunits, encoded by the nifD and the nifK genes respectively. Recently, the functional expression of a fusion NifD-K protein of nitrogenase was demonstrated in Azotobacter vinelandii, strongly implying that the MoFe protein is flexible as it could accommodate major structural changes, yet remain functional [M.H. Suh, L. Pulakat, N. Gavini, J. Biol. Chem. 278 (2003) 5353-5360]. This finding led us to further explore the type of interaction between the fused MoFe protein units. We aimed to determine whether an interaction exists between the two fusion MoFe proteins to form a homodimer that is equivalent to native heterotetrameric MoFe protein. Using the Bacteriomatch Two-Hybrid System, translationally fused constructs of NifD-K (fusion) with the full-length λCI of the pBT bait vector and also NifD-K (fusion) with the N-terminal α-RNAP of the pTRG target vector were made. To compare the extent of interaction between the fused NifD-K proteins to that of the β-β interactions in the native MoFe protein, we proceeded to generate translationally fused constructs of NifK with the α-RNAP of the pTRG vector and λCI protein of the pBT vector. The strength of the interaction between the proteins in study was determined by measuring the β-galactosidase activity and extent of ampicillin resistance of the colonies expressing these proteins. This analysis demonstrated that direct protein-protein interaction exists between NifD-K fusion proteins, suggesting that they exist as homodimers. As the interaction takes place at the β-interfaces of the NifD-K fusion proteins, we propose that these homodimers of NifD-K fusion protein may function in a similar manner as that of the heterotetrameric native MoFe protein. The observation that the extent of protein-protein interaction between the β-subunits of the native MoFe protein in Bacterio

Selección y caracterización de rizobacterias promotoras de crecimiento vegetal (RPCV asociadas al cultivo de algodón (Gossypium hirsutum

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Andrés Guzmán

2012-01-01

Full Text Available Título en ingles: Selection and characterization of plant growth promoting rhizobacteria (PGPR’s associated with cotton crop (Gossypium hirsutum Resumen: Como parte de las estrategias de una agricultura sostenible, se hace necesario disminuir el uso de fertilizantes nitrogenados de síntesis, mediante la utilización de los biofertilizantes. En particular, los géneros Azotobacter y Azospirillum son utilizados como agentes promotores de crecimiento vegetal debido a su capacidad para fijar nitrógeno atmosférico y producir hormonas de tipo indólico. Por tal razón, en este estudio se aislaron bacterias diazotróficas de los géneros Azotobacter y Azospirillum a partir de la rizósfera de cultivos de algodón en el Espinal (Tolima. Las poblaciones microbianas se caracterizaron fenotípicamente en los medios de cultivo semiespecíficos: Ashby y LG (Azotobacter sp. y NFb, LGI y Batata (Azospirillum sp.. La promoción de crecimiento vegetal se determinó mediante la actividad de la enzima nitrogenasa por medio de la técnica de reducción de acetileno y producción de índoles por el método colorimétrico de Salkowsky. Se obtuvieron 9 aislamientos tentativos de Azotobacter sp. y 4 de Azospirillum sp. Se presentaron diferencias significativas en la prueba de reducción de acetileno con las cepas presuntivas de Azotobacter sp.: NAT 9 (206.43 nmol C2H2 mL-1.h-1, NAT 4, (292.77 nmol C2H2 mL-1.h-1, y NAT 6 (460.60 nmol C2H2 mL-1.h-1 y en la producción de índoles de las cepas NAT 19 (19.87 μg.mL-1 y NAT 13 (20.08 μg.mL-1. Por su eficiencia in vitro en la promoción de crecimiento vegetal se seleccionaron las cepas NAT9, NAT4, NAT6, NAT19 y NAT13 para ser evaluadas como principio activo en futuros inoculantes para el algodón en esta zona del departamento del Tolima. Palabras clave: fijación biológica de nitrógeno; producción de índoles; promoción del crecimiento vegetal;  biofertilizantes. Abstract: As part of strategies for sustainable

Evaluación de la asociación bacterias fijadoras de nitrógeno - líneas interespecíficas de arroz-nitrógeno, en Typic haplustalf. Ibagué, Colombia

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Margarita M Vallejo

2008-01-01

Full Text Available El estudio se llevó a cabo en la hacienda Cauchitos, municipio de Ibagué, departamento del Tolima (Norte 4° 23' 51" y Oeste 75° 9' 7", 979 msnm, 24.3°C, bosque seco tropical (bs-T, con el objetivo de evaluar las asociaciones entre bacterias fijadoras de nitrógeno con inóculo y sin él en diez líneas interespecíficas de arroz, con tres dosis de nitrógeno (0%, 50% y 100% de 250 kg/ha-1 y tres repeticiones por tratamiento. La inoculación se realizó con 1 cm³ de unidades formadoras de colonias por 250 g de semilla de cada cultivar. Se aislaron 2.260 bacterias de los géneros Azotobacter spp y Azospirillum spp, se identificaron las especies A. brasilense, A. lipoferum, A. amazonense y del género Azotobacter las especies A. chroococcum, A. vinelandii, A. paspali y A. beijerinckii. Respecto al inóculo no se encontraron diferencias significativas al realizar su aplicación, se determinó que Azotobacter spp y Azospirillum spp fueron géneros típicos de la flora bacteriana en el cultivo del arroz y en condiciones de campo hubo efecto de los tratamientos en la flora bacteriana, y Azotobacter spp fue el predominante en cada uno de los tratamientos.

Genotypic characterization of Azotobacteria isolated from Argentinean soils and plant-growth-promoting traits of selected strains with prospects for biofertilizer production.

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Rubio, Esteban Julián; Montecchia, Marcela Susana; Tosi, Micaela; Cassán, Fabricio Darío; Perticari, Alejandro; Correa, Olga Susana

2013-01-01

The genetic diversity among 31 putative Azotobacter isolates obtained from agricultural and non-agricultural soils was assessed using rep-PCR genomic fingerprinting and identified to species level by ARDRA and partial 16S rRNA gene sequence analysis. High diversity was found among the isolates, identified as A. chroococcum, A. salinestris, and A. armeniacus. Selected isolates were characterized on the basis of phytohormone biosynthesis, nitrogenase activity, siderophore production, and phosphate solubilization. Indole-3 acetic-acid (IAA), gibberellin (GA3) and zeatin (Z) biosynthesis, nitrogenase activity, and siderophore production were found in all evaluated strains, with variation among them, but no phosphate solubilization was detected. Phytohormones excreted to the culture medium ranged in the following concentrations: 2.2-18.2 μ g IAA mL(-1), 0.3-0.7 μ g GA3 mL(-1), and 0.5-1.2 μ g Z mL(-1). Seed inoculations with further selected Azotobacter strains and treatments with their cell-free cultures increased the number of seminal roots and root hairs in wheat seedlings. This latter effect was mimicked by treatments with IAA-pure solutions, but it was not related to bacterial root colonization. Our survey constitutes a first approach to the knowledge of Azotobacter species inhabiting Argentinean soils in three contrasting geographical regions. Moreover, this phenotypic characterization constitutes an important contribution to the selection of Azotobacter strains for biofertilizer formulations.

Evaluation of the association nitrogen fixing bacterias interspecific – rice lines – nitrogen, in typic haplustalf. Ibagué, Colombia Evaluación de la asociación bacterias fijadoras de nitrógeno – líneas interespecíficas de arroz–nitrógeno, en Typic haplustalf. Ibagué, Colombia

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Bonilla Correa Carmen Rosa

2008-03-01

Full Text Available The study was carried out at the Cauchitos farm, Ibague municipality department of Tolima, with bounds: North 4°23'51"; and west 75°9'7";, 979 ansm, the average temperature is 24,3°C, tropical dry forest (bs–t in the Holdridge classification. The purpose of this study was to evaluate the association between the nitrogen fixation bacteries with and without inoculo in 10 interespecific rice lines with three nitrogen dosis (0, 50 and 100% de 250 kg/ ha^–1 and three repetitions. The inoculation was realized with 10⁸ former units of colonies per millimeter. 2.260 bacteries of the generums Azotobacter spp y Azospirrillum spp., and identification the species: Azospirillum brasilense, Azospirillum lipoferum, Azospirillum amazonense, were identified and from the genus Azotobacter were identified the species: A. choroococcum, A. vinelandii, A. paspali and A. veijerinckii. Weren't found none significative differences after the inoculation. Azotobacter spp and Azospirillum spp. were typical generums of the bacterian flora in the rice plantation and in field conditions were effect of the treatment effects in the bacterian . The Azotobacter spp was the predominant in generum in each one of the treatments.El estudio se llevó a cabo en la hacienda Cauchitos, municipio de Ibagué, departamento del Tolima (Norte 4° 23' 51"; y Oeste 75° 9' 7";, 979 msnm, 24.3°C, bosque seco tropical (bs–T, con el objetivo de evaluar las asociaciones entre bacterias fijadoras de nitrógeno con inóculo y sin él en diez líneas interespecíficas de arroz, con tres dosis de nitrógeno (0%, 50% y 100% de 250 kg/ha^–1 y tres repeticiones por tratamiento. La inoculación se

Non-symbiotic bacterial diazotrophs from of agricultural crops of San Carlos. Córdoba, Colombia

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Cecilia Lara Mantilla

2007-07-01

Full Text Available Diazotrophic Azotobacter sp and Azospirrillum sp bacteria were isolated from the rhizosphere of plantain, (Musa paradisiaca, corn, wheat and fallow areas (uncultivated, but covered by fallen leaves in the San Carlos region (in the Sinú valley in the Córdoba department, Colombia. Microbial populations were identified by biochemical tests; physiological characters were examined using Gram reaction in different mediums: Burk’s, Ashby and Jensen’s (Azotobacter sp and Burk’s, NFB and Congo-red medium (Azospirillum sp. The study was aimed at determining ion ammonium production from Azotobacter sp and Azospirrillum sp isolates; ion ammonium was quantified according to Berthelot’s colorimetric technique (phenol-hypochlorite. This method was modified and standardised in line with using a Perkin-Elmer Lamba 11 UV-Vis spectrometer. As a result of this study, 14 isolates have been shown to be ammonium-producers at concentrations ranging from 0.9 mg/l to 5.2 mg/l; A16PG (5.1545 mg/l and A26M1P (5.1743 mg/l yielded the highest ammonium concentrations for Azotobacter sp and A5M1G (4.6741 mg/l for Azospirrillum sp. Biological N2 fixation (BNF by associative diazotrophic bacteria has contributed towards increasing harvest yield, thereby reducing the need for nitrogenised fertilisers and the emission of greenhouse gases (such as N2O and obtaining economic and environmental benefits for farming.

Qualitative and qualitative characteristics of milk thistle (Silybum marianum L. in response to organic, biological and chemical fertilizers

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R. Yazdani Biuki

2016-04-01

Full Text Available In order to evaluate the effects of organic, biological and chemical fertilizers on yield and yield components of milk thistle (Silybum marianum L., an experiment was conducted at the Research Station of Ferdowsi University of Mashhad based on complete randomized block design with three replications and six treatments during year 2007. Treatments included inoculated seeds with Azotobacter, compost, vermicompost, combination of both Azotobacter and compost treatments, chemical NPK fertilizer and control (without any fertilizer. The traits such as number of branches per plant, plant height, number of inflorescences per plant, inflorescence diameter, number of seeds per capitol, 1000 seed weight, seed yield, biological yield, harvest index, oil percentage, silymarin percentage, silybin percentage, oil yield and silymarin yield were measured. The results showed that application of different types of organic fertilizers had no effect on yield components, but had significant effect on oil percentage of oil, silymarin and silybin of seed. Compost application resulted the highest oil percentage (20.1 compared to other treatments. There was no significant difference between control, chemical fertilizer, compost and Azotobacter treatments on silymarin percentage. In terms of silybin percentage, there was no significant difference between control, compost, Azotobacter and aztobacter+compost treatments. The chemical fertilizer treatment showed the lowest silybin percentage (16.4. There was a positive correlation between plant height and seed yield (r=0.68**. It seems that biofertilizers can consider as a replacement for chemical fertilizers in Milk thistle medicinal plant production.

Assessing the Effect of Organic Compounds, Biofertilizers and Chemical Fertilizers on Morphological Properties,yield and Yield Components of Forage Sorghum (Sorghum bicolor

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A.H Saeidnejad

2012-12-01

Full Text Available Recently, using the source of organic fertilizers and biofertilizers in sustainable crop production is growing. In order to evaluate the effect of organic compounds, biofertilizers and chemical fertilizer on morphological properties, yield and yield components of forage Sorghum (sorghum bicolor a field experiment was conducted in the Research Farm, College of Agriculture, Ferdowsi University of Mashhad in 2008.The treatments were seed inoculation with the combination of Azotobacter chroococcum and Azospirillum brasilense, Compost (15 t/ha, Vermicompost (10 t/ha, seed inoculation with Azotobacter and Azospirillum and compost (10t/ha, seed inoculation with Azotobacter chroococcum and Azospirillum brasilense and Vermicompost (7t/ha, seed inoculation with Pseudomonas flurescence, seed inoculation with Pseudomonas flurescence and Azotobacter chroococcum and Azospirillum brasilense combination, seed inoculation with Pseudomonas flurescence and compost (15t/ha, chemical fertilizer (80 kg/h urea fertilizer and 50 kg/h super phosphate fertilizer and control. Harvesting was performed in 2 cuts in flowering stage. Plant height, number of tiller per plant and SPAD reading was significantly affected by the treatments. Stem diameter was not affected by any treatments. There was a significant difference among all treatments in terms of fresh and dry forage yield. There were no significant differences among all treatments in terms of stem and leaf dry matter. In general, result of this experiment indicated that organic amendments and biofertilizers could be acceptable alternatives for chemical fertilizers.

Genotypic Characterization of Azotobacteria Isolated from Argentinean Soils and Plant-Growth-Promoting Traits of Selected Strains with Prospects for Biofertilizer Production

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Esteban Julián Rubio

2013-01-01

Full Text Available The genetic diversity among 31 putative Azotobacter isolates obtained from agricultural and non-agricultural soils was assessed using rep-PCR genomic fingerprinting and identified to species level by ARDRA and partial 16S rRNA gene sequence analysis. High diversity was found among the isolates, identified as A. chroococcum, A. salinestris, and A. armeniacus. Selected isolates were characterized on the basis of phytohormone biosynthesis, nitrogenase activity, siderophore production, and phosphate solubilization. Indole-3 acetic-acid (IAA, gibberellin (GA3 and zeatin (Z biosynthesis, nitrogenase activity, and siderophore production were found in all evaluated strains, with variation among them, but no phosphate solubilization was detected. Phytohormones excreted to the culture medium ranged in the following concentrations: 2.2–18.2 μg IAA mL−1, 0.3–0.7 μg GA3 mL−1, and 0.5–1.2 μg Z mL−1. Seed inoculations with further selected Azotobacter strains and treatments with their cell-free cultures increased the number of seminal roots and root hairs in wheat seedlings. This latter effect was mimicked by treatments with IAA-pure solutions, but it was not related to bacterial root colonization. Our survey constitutes a first approach to the knowledge of Azotobacter species inhabiting Argentinean soils in three contrasting geographical regions. Moreover, this phenotypic characterization constitutes an important contribution to the selection of Azotobacter strains for biofertilizer formulations.

Response Of Guava Trees (Psidium Guajava To Soil Applications Of Mineral And Organic Fertilisers And Biofertilisers Under Conditions Of Low Fertile Soil

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Shukla Sushil Kumar

2014-12-01

Full Text Available The goal of this study was to assess the influence of different organic fertilisers - vermicompost, mulching, Azotobacter, phosphate solubilising microbes (PSM and Trichoderma harzianum added each year to mineral fertilisers containing NPK and to farmyard manure (FYM on leaf nutrient status, tree growth, fruit yield and quality of guava grown in low fertile soil. The results revealed that vermicompost, bio-fertilisers and organic mulching resulted in yield and fruit quality boosters, as compared to application of NPK and FYM as the only organic fertiliser. Significant differences in plant height, canopy spread and stem girth of guava plants were obtained in combination, where Azotobacter, T. harzianum, PSM and organic mulching were applied. The leaf nutrient contents (N, P, K, Ca, Mg, Fe, Cu, Mn and Zn were within sufficient ranges. Fruit yields and quality were highest in combination, where vermicompost, Azotobacter, T. harzianum, PSM and organic mulching was applied. Fruit quality parameters viz. soluble solid concentration, titratable acidity, total sugars and ascorbic acid showed positive correlation with the available macro- and micronutrients in the soil.

Study of qualitative and quantitative yield and some agronomic characteristics of sunflower (Helianthus annus L. in response of seed inoculation with PGPR in various levels of nitrogen fertilizer

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H. Nazarly

2016-05-01

Full Text Available In order to study the qualitative and quantitative yield and some agronomic characteristics of sunflower (Helianthus annus L. in response to seed inoculation with PGPR under various levels of nitrogen fertilizer, a factorial experiment was conducted based on a randomized complete block design with three replications in field experimental University of Mohaghegh Ardabili during growing season of 2009-2010. Factors were nitrogen fertilizer in three levels (0, 80 and 160 kg N ha-1 as urea and seed inoculation with plant growth promoting rhizobacteria in four levels containing, without inoculation (as control, seed inoculation with Azotobacter chroococcum strain 5, Azospirillum lipoferum strain OF, Psedomunas strain 186. Results indicated that nitrogen levels and seed inoculation with Plant Growth Promoting Rhizobacteria (PGPR had significant effects on all of characteristics studied (except grain 1000 weight and stem diameter. Grain yield, plant height, head diameter, seed number per head, , yield and oil percentage, yield and protein percentage increased with increasing of nitrogen fertilizer and application of seed inoculation with PGPR. Response of grain yield wasn't the same for various levels of nitrogen fertilizer and seed inoculation with PGPR. The highest grain yield belonged to application of 160 kg N ha-1 and seed inoculation with Azotobacter. Means comparison showed that treatment compounds N160 × without inoculation with PGPR and N80 × seed inoculation with PGPR Azotobacter had similar grain yields. Thus, it can be suggested that in order to increasing of grain yield seed should be inoculated with Azotobacter bacteria × 80 kg N/ha in conditions of Ardabil region.

Study of some nitrogen transformation reactions as influenced by the agrochemicals in some soils of north Iraq by using labelled compounds. Part of a coordinated programme on isotopic-tracer-aided studies of agrochemical residue - soil biota interactions

International Nuclear Information System (INIS)

Shali, K.G.

1982-06-01

The effect is described of different pesticides when applied to autoclaved soils to which the mixture of nitrifier, ammonifier, and azotobacter were added and incubated for 90 days. The results are given of the respiration parameter of 14 CO 2 evolved at 30 and 60 days of incubation from soil samples obtained at depths of 15, 30, 45, and 60 cm. Graphs show the survival of mixture of nitrifier, ammonifier, and azotobacter treated with pesticides Benlate, Sevin, and Diptrex at three dose levels. Total bacterial counts as estimated by 14 C-glucose oxidation are also shown

Nitrogen fixed by wheat plants as affected by nitrogen fertilizer levels and Non-symbiotic bacteria

Energy Technology Data Exchange (ETDEWEB)

Soliman, S; Aly, S S.M.; Gadalla, A M [Soils and Water Dept., Atomic Energy Authority, Cairo (Egypt); Abou Seeda, M [Soils and Water Dept., National Res. Centre, Cairo (Egypt)

1995-10-01

Inorganic nitrogen is required for all egyptian soils for wheat. Free living and N 2-fixing microorganisms are able associate closely related with the roots of geraminacae. Pot experiment studies were carried out to examine the response of wheat plants to inoculation with Azospirillum Brasilense and Azotobacter Chroococcum, single or in combination, under various levels of ammonium sulfate interaction between both the inoculants increased straw or grain yield as well as N-uptake by wheat plants with increasing N levels. Results showed that grains of wheat plants derived over 19,24 and 15% of its N content from the atmospheric - N 2 (Ndfa) with application of 25,50 and 75 mg N kg-1 soil in the presence of + Azospirillum + azotobacter. The final amount of N 2-fixers. The highest values of N 2-fixed were observed with mixed inoculants followed by inoculation with Azospirillum and then azotobacter. The recovery of applied ammonium sulfate-N was markedly increased by inoculation with combined inoculants, but less in uninoculated treatments. Seeds inoculated with non-symbiotic fixing bacteria could be saved about 25 kg N without much affecting the grain yield. i fig., 4 tabs.

Nitrogen fixed by wheat plants as affected by nitrogen fertilizer levels and Non-symbiotic bacteria

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Soliman, S.; Aly, S.S.M.; Gadalla, A.M.; Abou Seeda, M.

1995-01-01

Inorganic nitrogen is required for all egyptian soils for wheat. Free living and N 2-fixing microorganisms are able associate closely related with the roots of geraminacae. Pot experiment studies were carried out to examine the response of wheat plants to inoculation with Azospirillum Brasilense and Azotobacter Chroococcum, single or in combination, under various levels of ammonium sulfate interaction between both the inoculants increased straw or grain yield as well as N-uptake by wheat plants with increasing N levels. Results showed that grains of wheat plants derived over 19,24 and 15% of its N content from the atmospheric - N 2 (Ndfa) with application of 25,50 and 75 mg N kg-1 soil in the presence of + Azospirillum + azotobacter. The final amount of N 2-fixers. The highest values of N 2-fixed were observed with mixed inoculants followed by inoculation with Azospirillum and then azotobacter. The recovery of applied ammonium sulfate-N was markedly increased by inoculation with combined inoculants, but less in uninoculated treatments. Seeds inoculated with non-symbiotic fixing bacteria could be saved about 25 kg N without much affecting the grain yield. i fig., 4 tabs

The effect of microbial inocula on the growth of black locust, Siberian elm and silver maple seedlings

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Hajnal-Jafari Timea

2014-01-01

Full Text Available Growth and development of forest plants depend mostly on the soil microbial activity since no mineral or organic fertilizers are applied. Microbial processes can be activated and conditions for plants development improved with the introduction of selected microorganisms in the soil. With the aim of obtaining quality planting material in a shorter period of time, the effects of Azotobacter chroococcum and Streptomyces sp. on the early growth of black locust (Robinia pseudoacacia, Siberian elm (Ulmus pumila and silver-leaf maple (Acer dasycarpum were investigated in this study. Microorganisms were applied individually and in a mixture (1:1. Plant height was measured on the 90th, 120th and 180th day after planting. Plant diameter, as well as the number of actinomycetes and azotobacters was measured at the end of the vegetation period (180 days after planting. Applied microorganisms had a positive effect on the seedling height in all three plant species, with the best effect found in the black locust. Effectiveness of applied microorganisms on seedling diameter was the highest in the silver-leaf maple. The largest number of azotobacters was found in the rhizosphere of black locust. Number of microorganisms from both groups was increased in the inoculated variants. [Projekat Ministarstva nauke Republike Srbije, br. III 43002

Kinetic Studies of Iron Deposition Catalyzed by Recombinant Human Liver Heavy, and Light Ferritins and Azotobacter Vinelandii Bacterioferritin Using O2 and H2O2 as Oxidants

Science.gov (United States)

Bunker, Jared; Lowry, Thomas; Davis, Garrett; Zhang, Bo; Brosnahan, David; Lindsay, Stuart; Costen, Robert; Choi, Sang; Arosio, Paolo; Watt, Gerald D.

2005-01-01

The discrepancy between predicted and measured H2O2 formation during iron deposition with recombinant heavy human liver ferritin (rHF) was attributed to reaction with the iron protein complex [Biochemistry 40 (2001) 10832-10838]. This proposal was examined by stopped-flow kinetic studies and analysis for H2O2 production using (1) rHF, and Azotobacter vinelandii bacterial ferritin (AvBF), each containing 24 identical subunits with ferroxidase centers; (2) site-altered rHF mutants with functional and dysfunctional ferroxidase centers; and (3) rccombinant human liver light ferritin (rLF), containing 110 ferroxidase center. For rHF, nearly identical pseudo-first-order rate constants of 0.18 per second at pH 7.5 were measured for Fe(2+) oxidation by both O2 and H2O2, but for rLF, the rate with O2 was 200-fold slower than that for H2O2 (k-0.22 per second). A Fe(2+)/O2 stoichiometry near 2.4 was measured for rHF and its site altered forms, suggesting formation of H2O2. Direct measurements revealed no H2O2 free in solution 0.5-10 min after all Fe(2+) was oxidized at pH 6.5 or 7.5. These results are consistent with initial H2O2 formation, which rapidly reacts in a secondary reaction with unidentified solution components. Using measured rate constants for rHF, simulations showed that steady-state H2O2 concentrations peaked at 14 pM at approx. 600 ms and decreased to zero at 10-30 s. rLF did not produce measurable H2O2 but apparently conducted the secondary reaction with H2O2. Fe(2+)/O2 values of 4.0 were measured for AvBF. Stopped-flow measurements with AvBF showed that both H2O2 and O2 react at the same rate (k=0.34 per second), that is faster than the reactions with rHF. Simulations suggest that AvBF reduces O2 directly to H2O without intermediate H2O2 formation.

NCBI nr-aa BLAST: CBRC-LAFR-01-0111 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-LAFR-01-0111 ref|ZP_00415494.1| Binding-protein-dependent transport systems in...ner membrane component [Azotobacter vinelandii AvOP] gb|EAM07348.1| Binding-protein-dependent transport systems

Studies on phosphorus utilization as influenced by bacterial seed inoculation and phosphorus fertilization in summer mung (Vigna radiata L. Wilczek)

International Nuclear Information System (INIS)

Kothari, S.K.; Saraf, C.S.

1988-01-01

A greenhouse experiment was conducted with four types of bacterial inoculation (Rhizobium alone; Rhizobium along with Azotobacter chroococcum; Rhizobium along with Azospirillum brasilense and no inoculation) and three levels of phosphorus ( 32 P labelled SSP) application (O, 6.5 ppm and 13.0 ppm P). Inoculation with Rhizobium along with Azotobacter chroococcum was found to be better than Rhizobium alone or Rhizobium along with Azospirillum brasilense in respect of leaf, stem, root and nodule dry weight, phosphorus uptake and utilization efficiency. P application upto 6.5 ppm significantly increased leaf, stem, root and nodule dry weight and phosphorus uptake. Per cent phosphorus derived from fertilizer (per cent pdff) and fertilizer P uptake significantly increased while P utilization efficiency significantly decreased with increasing levels of P application. (author). 12 refs., 2 tables

Effects of Azotobacter and Azospirillum and Levels of Manure on Quantitative and Qualitative Traits of Safflower (Carthamus tinctorius L.

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maryam shahraki

2016-07-01

Full Text Available Introduction The demand for food and agricultural products are increasing in a line of population increasing in the world (Alexandratos, 2003. It is possible to increase the quality and quantity of agricultural products via extending the farms and producing more products (Astaaraei and Koocheki, 1995. Environmental problems caused by synthetic fertilizers and the high levels of producing and introducing such chemicals, have been encouraged the researchers to apply bio-fertilizers for increasing the production in a frame of sustainable agriculture (Rajendran and Devarj, 2004. In this study, the economical yield and agronomy index of Safflower (Carthamus tinctorius L. in manure and bio fertilizers treatments was studied. Materials and method This study was conducted in Agricultural Research Institute, University of Zabol during winter season, 2013. Safflower seeds were planted in sandy loam with pH 8.2. The experimental design was factorial in a frame on randomized completely blocks with three replications. The manure as a first factor had three levels, including no treatment (control, 20 and 30 t.ha-1, while second factor was bio-fertilizer treatment with 4 levels, including no treatment (control, Azosprilium (Azo, Azotobacter (Azt and combined treatment of Azo+Azt. The processed manure and bacteria obtained from local farmers were used in this study. Populations of 108 bacteria were prepared and 24 hours before sowing, seeds were soaked in bacteria. After land preparation, experimental plots were (2.5 × 2 m2 created and treated seeds were planted (40 plants.m-2 manually and plantation was watered immediately. In this study plant height, number of heads in bush, number of seeds per head, seed weight per head, seed weight, grain and biological yield, harvest index, leaf chlorophyll, protein and oil percent were studied. Economical yield and agronomy indices of Safflower were calculated at the end of the season and data were analyzed using SAS

Characterization of Diazotrophs Containing Mo-Independent Nitrogenases, Isolated from Diverse Natural Environments

Science.gov (United States)

Molybdenum-independent nitrogenases were first described in the nitrogen-fixing bacterium Azotobacter vinelandii and have since been described in other diazotrophic bacteria. Previously, we reported the isolation of seven diazotrophs with Molybdenum-independent nitrogenases from aquatic environments...

Efficacy of organic matter and some bio-inoculants for the management of root-knot nematode infesting tomato

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Neha Khan

2015-06-01

Full Text Available Efficiency of an organic matter like Tagetes erecta and bioinoculants Azotobacter chroococcum and Glomus fasciculatum was investigated in tomato cultivar ‘Pusa Ruby’ when inoculated individually as well as concomitantly for the management of the root-knot nematode, Meloidogyne incognita in terms of growth parameters such as plant length, fresh and dry weights, chlorophyll content, per cent pollen fertility and mycorrhization. Greatest reduction in the numbers of second-stage juveniles in soil, number of root-galls, egg-masses and nematode multiplication was recorded with combined application of T. erecta and bio-inoculants A. chroococcum and G. fasciculatum as compared to untreated control and other treatments. Similarly, the greatest improvement in the plant growth and biomass of tomato was noted in the same treatments. However, individual inoculation of these bio-inoculants and organic fertilizers also showed significant enhancement but was less as compared to combined treatment. A. chroococcum was found most effective against disease incidence followed by G. fasciculatum and T. erecta. Parameters like NP and K contents were significantly enhanced in those plants which received combined treatments of organic matter and bio-inoculants. Azotobacter was found more efficacious against nematodes than Glomus fasciculatum. Organic matter also influenced the activity of bio-inoculants, more with the Azotobacter than G. fasciculatum. DOI: http://dx.doi.org/10.3126/ije.v4i2.12643 International Journal of Environment Vol.4(2 2015: 206-220

A metodologia de superfície de resposta como ferramenta para a avaliação da produção de alginato e poli-hidroxibutirato pela Azotobacter vinelandii - doi: 10.4025/actascitechnol.v32i2.1792

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Adriana Navarro da Silva

2010-07-01

Full Text Available O alginato é um polissacarídeo normalmente extraído de paredes celulares de algas marrons e utilizado nas indústrias de alimentos, farmacêuticas e biotecnológicas. A produção é concentrada no cultivo de algas marinhas marrons, mas várias bactérias do gênero Pseudomonas e Azotobacter produzem alginato. A estrutura química dos alginatos produzidos por algas é similar a dos sintetizados pela A. vinelandii. Esta bactéria também produz polímeros intracelulares como o poli-hidroxibutirato (PHB, conhecido como bioplástico. Neste trabalho, estudou-se a produção simultânea do alginato e PHB pela A. vinelandii, utilizando-se sacarose e diferentes parâmetros de fermentação em agitador orbital rotatório. Os valores ótimos para produção destes compostos foram determinados pela MSR. O 1º experimento foi um planejamento fatorial fracionado 26-2. O 2º foi baseado nas variáveis significativas do 1º experimento, resultando em um planejamento fatorial completo 33-0. Verificou-se, do primeiro para o segundo, aumento na produtividade do PHB de 12 para 45 mg g-1 de célula h-1 e do alginato de 100 para 1.600 mg g-1 de célula h-1. A produtividade de ambos os compostos foi máxima na temperatura de incubação de 62ºC, no menor tempo de incubação (18h e na concentração de sacarose de 11 g L-1. Em ambos os experimentos, o PHB extraído apresentou pureza de 94%.

Kinetics of nitrogenase from Azotobacter vinelandii

NARCIS (Netherlands)

Duyvis, M.G.

1997-01-01

Nitrogenase has been the subject of many investigations since the early 1960's. The catalytic mechanism of nitrogenase is unique because it couples the transfer of electrons with the hydrolysis of MgATP. The details of the mechanism are still to be revealed. The work described in this

Effects of Rhamnolipid and Microbial Inoculants on the Vermicomposting of Green Waste with Eisenia fetida.

Science.gov (United States)

Gong, Xiaoqiang; Wei, Le; Yu, Xin; Li, Suyan; Sun, Xiangyang; Wang, Xinyu

2017-01-01

The effects of adding the biosurfactant rhamnolipid, the lignolytic and cellulolytic fungus Phanerochete chrysosporium, and the free-living nitrogen-fixing bacterium Azotobacter chrococcum on vermicomposting of green waste with Eisenia fetida was investigated. The addition of rhamnolipid and/or either microorganism alone or in all combinations significantly increased E. fetida growth rate, the number of E. fetida juveniles and cocoons, the population densities of cellulolytic fungi and Azotobacter bacteria, and cellulase and urease activities in the vermicomposts. The quality of the final vermicompost (in terms of electrical conductivity, nutrient content, C/N ratio, humic acid content, lignin and cellulose contents, and phytotoxicity to germinating seeds) was enhanced by addition of rhamnolipid and/or microorganisms. The physical characteristics of vermicomposts produced with rhamnolipid and/or microorganisms were acceptable for agricultural application. The best quality vermicompost was obtained with the combined addition of P. chrysosporium, A. chrococcum, and rhamnolipid.

Cost effective pilot scale production of biofertilizer using Rhizobium ...

African Journals Online (AJOL)

We standardized the protocol for pilot scale production of Rhizobium and Azotobacter biofertilizer technology using region specific and environmental stress compatible strains isolated from various agro climatic regions of Odisha, India. The cost benefit of biofertilizer production through a cottage industry is also presented.

The Nifl PAS domain: Insight into its structure and function

NARCIS (Netherlands)

Hefti, M.H.

2003-01-01

Azotobacter vinelandii is an aerobic soil-dwelling organism with a wide variety of metabolic capabilities which include the ability to fix atmospheric nitrogen by converting it to ammonia. The biosynthesis of ammonia is controlled by 15 to 20 different nif gene products. The activation

Effect of different fertilizers on the microbial activity and productivity ...

African Journals Online (AJOL)

This study was conducted to evaluate the effect of the application of different rates of mineral nitrogen, well rotten farmyard manure and Klebsiella planticola SL09- based microbial biofertilizer (enteroplantin) on the count of soil microorganisms (total microbial count, counts of Azotobacter, oligonitrophilic bacteria, fungi and ...

Effect of microwave irradiation on alfalfa seeds germination and nitrogenase activity of endophytic diazotrophs in seeds

International Nuclear Information System (INIS)

Zhang Shuqing; Li Jianfeng; Shi Shangli; Huo Pinghui; Zhu Xinqiang; Zhao Wenhan; Tao Rong

2011-01-01

Various microwave powers were used to irradiate alfalfa seeds with various time to study the effect of microwave irradiation on nitrogenase activity of endogenous azotobacter and germination of seeds. Germination rate, germination speed and nitrogenase activity of pure cultures that derived from seed-carried azotobacter were tested. The results indicate that : 800 W, 20 s and 500 W, 40 s are found with highest germination rate on the 1 st day, which is 122% and 88.9% times higher than the control group (P th day is 29.8% and 41.9% times longer than the control group, and more sensitive nitrogenase activity is found on condition of various time than various powers. Short time treatments on condition of the two irradiation powers can increase nitrogenase activity conspicuously, and the treatments that treated more than 32 s make nitrogenase activity lower than the control group, conspicuously. Nitrogenase activity is found 104.9% times higher than the control group on condition of 24 s. (authors)

Increased root exudation of /sup 14/C-compounds by sorghum seedlings inoculated with nitrogen-fixing bacteria

Energy Technology Data Exchange (ETDEWEB)

Lee, K.J. (Institute of Forest Genetics, Suweon (Republic of Korea)); Gaskins, M.H. (Florida Univ., Gainesville (USA). Dept. of Agriculture)

1982-01-01

Organic components leaked from Sorghum bicolor seedlings ('root exudates') were examined by recovering /sup 14/C labelled compounds from root solutions of seedlings inoculated with Azospirillum brasilense, Azotobacter vinelandii or Klebsiella pneumoniae nif-. Up to 3.5% of the total /sup 14/C recovered from shoots, roots, and nutrient solutions was found in the root solutions. Inoculation with Azospirillum and Azotobacter increased the amounts of /sup 14/C and decreased the amounts of carbohydrates in the root solutions. When sucrose was added as a carbon source for the bacteria, the increase of /sup 14/C in the solutions did not occur. Quantities of /sup 14/C found in the root solutions were proportional to amounts of mineral nitrogen supplied to the plants. Bacterial growth also was proportional to nitrogen levels. When sorghum plants were grown in soil and labelled with /sup 14/CO/sub 2/, about 15% of the total /sup 14/C recovered within 48 hours exposure was found in soil leachates.

Increased root exudation of 14C-compounds by sorghum seedlings inoculated with nitrogen-fixing bacteria

International Nuclear Information System (INIS)

Lee, K.J.; Gaskins, M.H.

1982-01-01

Organic components leaked from Sorghum bicolor seedlings ('root exudates') were examined by recovering 14 C labelled compounds from root solutions of seedlings inoculated with Azospirillum brasilense, Azotobacter vinelandii or Klebsiella pneumoniae nif-. Up to 3.5% of the total 14 C recovered from shoots, roots, and nutrient solutions was found in the root solutions. Inoculation with Azospirillum and Azotobacter increased the amounts of 14 C and decreased the amounts of carbohydrates in the root solutions. When sucrose was added as a carbon source for the bacteria, the increase of 14 C in the solutions did not occur. Quantities of 14 C found in the root solutions were proportional to amounts of mineral nitrogen supplied to the plants. Bacterial growth also was proportional to nitrogen levels. When sorghum plants were grown in soil and labelled with 14 CO 2 , about 15% of the total 14 C recovered within 48 hours exposure was found in soil leachates. (orig.)

Surfing the free energy landscape of flavodoxin folding

NARCIS (Netherlands)

Bollen, Y.J.M.

2004-01-01

The research described in this thesis has been carried out to obtain a better understanding of the fundamental rules describing protein folding. Protein folding is the process in which a linear chain of amino acids contracts to a compact state in which it is active. Flavodoxin from Azotobacter

Browse Title Index

African Journals Online (AJOL)

Items 51 - 100 of 117 ... Vol 5, No 2 (2004), Evaluation of three indigenous Multi-purpose tree species for agroforestry purposes on alfisols in South Western Nigeria, Abstract ... Vol 5, No 1 (2004), Growth response of tomato (Lycopersicum esculentum Mill) inoculated with Azotobacter croococcum in an alfisol, Abstract.

Optimising carbon and nitrogen sources for Azotobacter ...

African Journals Online (AJOL)

user

2011-04-11

Apr 11, 2011 ... Edificio Manuel Ancizar, Universidad Nacional de Colombia, Bogotá, D.C., Colombia. ..... 0,04. 0,06. 0,08. 0,10. Run 9 Run 10 Run 13 Run 14. A cetylen e red u ctio n. (n m .... Biological nitrogen fixation in the tropics: Social.

Bio fertilization of Cereal and Legume Crops for Increasing Soil available P Uptake Using Nuclear Technique

International Nuclear Information System (INIS)

Soliman, S.; El-Gandour, E. A.; El Gala, A. M.; Ishac, Y. Z.

2004-01-01

Application of N and P in uncommon sources such as N 2 -fixers and AM fungi considered as an important source to save money and reduce pollution. In this concern, two pot experiments were carried out in sandy soils, to study the role of these neutral organisms in increasing the fertility of sandy soil. Wheat and faba bean were used. Seeds of wheat or faba bean were inoculated with Azotobacter or Rhizobium and planted in soils inoculated with and without AM fungi. A 20 mg P/kg soil in the form of single super phosphate (15.5 % P 2 O 5 ) or rock-P (26.6% P 2 O 5 ) were applied in the first experiment while KH 2 PO 4 was added in the second one. Dry weight, spore number, root infection, total and specific P were also determined. Maximum shoot growth were gained when either, wheat or faba bean inoculated with mycorrhizae and N2-fixers relative to the control. it was reached to 54 and 73%, respectively. Phosphorus uptake for shoots of both wheat and faba bean had been significantly increased upon inoculating with AM and/or Azotobacter or Rhizobium. Addition of fertilizer P help to identify the P uptake from soil or fertilizer. Mycorrhizal plants induced significant increase in Pdff by about 39 and 27% over inoculated with Azotobacter for wheat and Rhizobium for faba bean and it reached to 95 and 79% when inoculated with combined inoculation. This may be due to AM fungi absorb more available P than do nonmycorrhizal roots. FUE was increased from about 5 to 10% for wheat; 6 to 19% for faba bean. It can be concluded that, bio fertilizers can increase crop production and soil fertility. Rock-P might be recommended as a source of P fertilizer to be applied with AM fungi. (Authors)

Integrated systems for biopolymers and bioenergy production from organic waste and by-products: a review of microbial processes.

Science.gov (United States)

Pagliano, Giorgia; Ventorino, Valeria; Panico, Antonio; Pepe, Olimpia

2017-01-01

Recently, issues concerning the sustainable and harmless disposal of organic solid waste have generated interest in microbial biotechnologies aimed at converting waste materials into bioenergy and biomaterials, thus contributing to a reduction in economic dependence on fossil fuels. To valorize biomass, waste materials derived from agriculture, food processing factories, and municipal organic waste can be used to produce biopolymers, such as biohydrogen and biogas, through different microbial processes. In fact, different bacterial strains can synthesize biopolymers to convert waste materials into valuable intracellular (e.g., polyhydroxyalkanoates) and extracellular (e.g., exopolysaccharides) bioproducts, which are useful for biochemical production. In particular, large numbers of bacteria, including Alcaligenes eutrophus , Alcaligenes latus , Azotobacter vinelandii , Azotobacter chroococcum , Azotobacter beijerincki , methylotrophs, Pseudomonas spp., Bacillus spp., Rhizobium spp., Nocardia spp., and recombinant Escherichia coli , have been successfully used to produce polyhydroxyalkanoates on an industrial scale from different types of organic by-products. Therefore, the development of high-performance microbial strains and the use of by-products and waste as substrates could reasonably make the production costs of biodegradable polymers comparable to those required by petrochemical-derived plastics and promote their use. Many studies have reported use of the same organic substrates as alternative energy sources to produce biogas and biohydrogen through anaerobic digestion as well as dark and photofermentation processes under anaerobic conditions. Therefore, concurrently obtaining bioenergy and biopolymers at a reasonable cost through an integrated system is becoming feasible using by-products and waste as organic carbon sources. An overview of the suitable substrates and microbial strains used in low-cost polyhydroxyalkanoates for biohydrogen and biogas

Impact of azadirachtin, an insecticidal allelochemical from neem on soil microflora, enzyme and respiratory activities.

Science.gov (United States)

Gopal, Murali; Gupta, Alka; Arunachalam, V; Magu, S P

2007-11-01

The effect of 10% azadirachtin granules (alcoholic extract of neem seed kernel mixed with China clay) was studied on the population of bacteria, actinomycetes, fungi, Azotobacter and nitrifying bacteria; soil dehydrogenase, phosphatase and respiratory activities on 0, 15th, 30th, 60th and 90th days after application in sandy loam soil collected from the fields. It was observed that baring the Azotobacter sp., azadirachtin at all the doses exerted a suppressive effect on the rest of the microbial communities and enzyme activities in the initial 15 day period. The population of bacteria, actinomycetes besides phosphatase and respiratory activities recovered after 60th day and subsequently increased significantly. The fungi and nitrifiers were most sensitive groups as their numbers were reduced significantly throughout the studies. The two times and five times recommended dose of azadirachtin had very high biocidal effects on the soil microorganisms and its activities. However, analysis of the data by the Shannon Weaver index showed that azadirachtin reduces both the form and functional microbial diversity at all doses.

GenBank blastx search result: AK061948 [KOME

Lifescience Database Archive (English)

Full Text Available droxybutyrate biosynthetic beta-ketothiolase (phbA), and PHB synthase (phbC) genes, complete cds.|BCT BCT 1e-56 +3 ... ...AK061948 001-042-E07 AF267243.2 Azotobacter vinelandii PhbF (phbF), putative phasin protein PhbP (phbP), putative transcription activator PhbR (phb...R), acetoacetyl-CoA reductase (phbB), polyhy

GenBank blastx search result: AK059654 [KOME

Lifescience Database Archive (English)

Full Text Available droxybutyrate biosynthetic beta-ketothiolase (phbA), and PHB synthase (phbC) genes, complete cds.|BCT BCT 3e-82 +1 ... ...AK059654 001-031-C10 AF267243.2 Azotobacter vinelandii PhbF (phbF), putative phasin protein PhbP (phb...P), putative transcription activator PhbR (phbR), acetoacetyl-CoA reductase (phbB), polyhy

Characterization of the Paenibacillus beijingensis DSM 24997 GtfD and its glucan polymer products representing a new glycoside hydrolase 70 subfamily of 4,6-α-glucanotransferase enzymes

NARCIS (Netherlands)

Gangoiti, Joana; Lamothe, Lisa; van Leeuwen, Sander Sebastiaan; Vafiadi, Christina; Dijkhuizen, Lubbert

2017-01-01

Previously we have reported that the Gram-negative bacterium Azotobacter chroococcum NCIMB 8003 uses the 4,6-α-glucanotransferase GtfD to convert maltodextrins and starch into a reuteran-like polymer consisting of (α1→4) glucan chains connected by alternating (α1→4)/(α1→6) linkages and (α1→4,6)

Soil microbial activity under conventional and organic production of bean and maize

Directory of Open Access Journals (Sweden)

Marinković Jelena B.

2016-01-01

Full Text Available The objective of this study was to compare the effects of conventional and organic production system on microbial activity in the soil cultivated with bean and maize crops. The trial in Đurđevo was set up according to the conventional farming system, while organic farming system was used in Futog. Two maize hybrids and two bean cultivars were used in the trial. Soil samples were collected in two periods during 2014 (before sowing, at flowering stage of bean crops, and at 9-11 leaf stage of maize at two depths, at both locations. The following microbiological parameters were tested: the total number of micro­organisms, number of ammonifiers, Azotobacter sp., free nitrogen fixing bacteria, fungi, actinomycetes, and activity of dehydrogenase enzyme. The results showed that the total number of microorganisms, number of free N-fixers and dehydrogenase activity were higher within organic production, while Azotobacter sp. was more abundant in conventional production. Variations in the number of ammonifiers, fungi and actinomycetes in relation to the type of production were not obtained. Significant differences in microbial activity were also obtained between period and depths of sampling.

Biotechnological uses of Azotobacter vinelandii : Current state, limits ...

African Journals Online (AJOL)

African Journal of Biotechnology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 9, No 33 (2010) >. Log in or Register to get access to full text downloads.

The Effectiveness of Biofertilizer on Plant Growth Soyb Ea N “Edam Am E” (Glycin Max)

OpenAIRE

Sudiarti, Diah

2017-01-01

This study aimed at determining the effectiveness of biofertilizer with different concentrations on plant growth of soybean “edamame” (glycin max). Biofertilizer in this study consists of microbial consortia (lactobacillus, pseudomonas, bacillus, saccharomyces, rhizobium, azotobacter, azospirillum, and cellulomonas). The treatment consists of 3 biofertilizer concentrations (25%, 50%, dan 75%), as well as the negative control and positive control (100% chemical fertilizer equivalent 5g/plant)....

Selection of rhizosphere local microbial as bioactive inoculant based on irradiated compost

International Nuclear Information System (INIS)

Dadang Sudrajat; Nana Mulyana; Arief Adhari

2014-01-01

One of the main components of carrier based on irradiation compost for bio organic fertilizer is a potential microbial isolates role in nutrient supply and growth hormone. This research was conducted to obtain microbial isolates from plant root zone (rhizosphere), further isolation and selection in order to obtain potential isolates capable of nitrogen fixation (N 2 ), resulting in growth hormone (Indole Acetic Acid), and phosphate solubilizing. Selected potential isolates used as bioactive microbial inoculants formulation in irradiation compost based. Forty eight (48) rhizosphere samples were collected from different areas of West and Central Java. One hundred sixteen (116) isolates have been characterized for their morphological, cultural, staining and biochemical characteristics. Isolates have been selected for further screening of PGPR traits. Parameters assessed were Indole Acetic Acid (IAA) content analysis with colorimetric methods, dinitrogen fixation using gas chromatography, phosphate solubility test qualitatively (in the media pikovskaya) and quantitative assay of dissolved phosphate (spectrophotometry). Evaluation of the ability of selected isolates on the growth of corn plants were done in pots. The isolates will be used as inoculant consortium base on compost irradiation. The selection obtained eight (8) bacterial isolates identified as Bacillus circulans (3 isolates), Bacillus stearothermophilus (1 isolate), Azotobacter sp (3 isolates), Pseudomonas diminuta (1 isolate). The highest phosphate released (91,21 mg/l) was by BD2 isolate (Bacillus circulan) with a holo zone size (1.32 cm) on Pikovskaya agar medium. Isolate of Pseudomonas diminuta (KACI) was capable to produce the highest IAA hormone (74.34 μg/ml). The highest nitrogen (N 2 ) fixation activity was shown by Azotobacter sp isolates (KDB2) at a rate of 235.05 nmol/hour. The viability test showed that all selected isolates in compost irradiation carrier slightly decreased after 3 months of

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

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Yousefi Sonia

2017-06-01

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

Characterization of diazotrophic bacteria non-symbiotic associated with eucalyptus (eucalyptus sp.) in Codazzi, Cesar (Colombia)

International Nuclear Information System (INIS)

Obando Castellanos, Dolly Melissa; Burgos Zabala, Ludy Beatriz; Rivera Botia, Diego Mauricio; Rubiano Garrido, Maria Fernanda; Divan Baldini, Vera Lucia; Bonilla Buitrago, Ruth Rebeca

2010-01-01

The effect of climatic seasons (rainy and dry) and the stratum sample (rhizospheric soil, roots and leaves) the population of the genera Azotobacter, Beijerinckia, Derxia, Azospirillum, Herbaspirillum, Gluconacetobacter and Burkholderia in soil rhizosphere, roots and leaves of eucalyptus (eucalyptus sp.). It also assesses their ability to produce indoles compounds as plant growth promoters and their acetylene reduction activity as an indicator of biological fixation of nitrogen. The results showed no statistically significant differences in the Duncan test (p ≤ 0.05) in the population with respect to the climate epoch, suggesting that these bacteria are able to tolerate stress conditions by different physiological mechanisms. With respect to the stratum sample isolates attempts of Herbaspirillum sp. and Azospirillum sp. significant differences in rhizospheric soil and roots. we obtained 44 isolates of which were grouped by phenotypic characterization as 14 suspected of Beijerinckia sp., 12 Azotobacter sp., 8 Derxia sp., 4 Herbaspirillum sp., 5 Azospirillum sp., 1 Gluconacetobacter sp. and 1 Burkholderia sp. due to their high potential were selected isolates C27, C26 and C25. These four strains present the best values of efficiency in vitro, exceeding production values of the reference strains used (A. chroococcum (AC1) and a. brasilense (SP7)).

Stage-specific requirement for Isa1 and Isa2 proteins in the mitochondrion of Trypanosoma brucei and heterologous rescue by human and Blastocystis orthologues

Czech Academy of Sciences Publication Activity Database

Long, Shaojun; Changmai, Piya; Tsaousis, A.D.; Skalický, Tomáš; Verner, Zdeněk; Wen, Yan-Zi; Roger, A. J.; Lukeš, Julius

2011-01-01

Roč. 81, č. 6 (2011), 1403-1418 ISSN 0950-382X R&D Projects: GA ČR GA204/09/1667; GA MŠk LC07032; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518 Keywords : IRON-SULFUR CLUSTER * ESCHERICHIA-COLI * ASSEMBLY PROTEIN * SACCHAROMYCES-CEREVISIAE * AZOTOBACTER-VINELANDII * CYSTEINE DESULFURASE * CRYSTAL-STRUCTURE * BINDING ACTIVITY * GENE-CLUSTER Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.010, year: 2011

Microbiological properties of dystric cambisols in region of eastern Serbia depending on exploitation way

OpenAIRE

Rasulić, Nataša; Delić, Dušica; Stajković-Srbinović, Olivera; Jošić, Dragana; Dolovac, Nenad; Kuzmanović, Đorđe

2013-01-01

One of the most represented types of soil in the hilly-mountainous region of Eastern Serbia is the dystric cambisol. Aiming to establish biogenity of such type of soil in Eastern Serbia, representation of the total microflora, fungi, actinomycetes, ammonifiers, azotobacters and oligonitrofills has been examined as well as dehydrogenase activity of the stated type of soil. The samples were taken from soils used in three different ways: plough-fields, orchards and forests. The standard microbio...

Biological activity of soils strongly polluted with sulfur

Energy Technology Data Exchange (ETDEWEB)

Krol, M; Maliszewska, W; Siuta, J

1972-01-01

Studies were carried out on soils strongly polluted with sulfur and acidified (to pH 1.4). The soils were subjected to an intensive liming. In field and pot experiments, the authors determined: the total quantity of bacteria, actinomycetes, fungi, azotobacter, nitrifiers, proteolytic activity of microorganisms, activity of ammonifiers and the number of sulfur-oxidizing and sulfate-reducing bacteria. It was found that intensive liming of sulfur-affected soils restored their biological activity. 8 references, 5 figures, 1 table.

Population of bacteria from soil in Tudu-Aog village, Passi district, Bolaang Mongondow, North Sulawesi

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RIANI HARDININGSIH

2004-01-01

Full Text Available An experiment was conducted in order to know the population of bacteria from soil in Tudu-Aog village, Passi district, Bolaang Mongondow, North Sulawesi, the purpose of the research was to study the population of bacteria from soil. Fourthy six soil samples were taken from two location, namelyTudu-Aog village and Bugis mountain. Isolation was done by dilution methods on YEMA medium (for Rhizobium bacteria, Winogradsky’s (for Azotobacter bacteria, Pycosvkaya (for Phosphat Solubilizing Bacteria, and selective Difco Pseudomonas (for Pseudomonas bacteria. Incubation at room temperature (27-280C until 15 days, and the enumeration with plate count method. The highest enumeration of Rhizobium bacteria with plant rhizosphere of Alocasia esculenta (27x105 CFU/g soil, Theobroma cacao (29x105 CFU/g soil,and Euphorbia paniculata (26x105 CFU/g soil, Azotobacter bacteria with plant rhizosphere of Lycopersicum esculantum (38x105 CFU/g soil, Eugenia aromaticum (43x105 CFU/g soil, Andropogon sp. (34x105 CFU/g soil, Phosphat Solubilizing bacteria with plant rhizosphere of Sechium edule (27x105 CFU/g soil, Cinnamomum sp. (48x105 CFU/g soil, Cyathea sp. (72x105 CFU/g soil, and Pseudomonas bacteria with plant rhizosphere of Oryza sativa (18x105 CFU/g soil, Vanilla sp. (12x105 CFU/g soil, dan Saurauia sp.(19x105 CFU/g soil.

Medio de cultivo utilizando residuos-sólidos para el crecimiento de una bacteria nativa con potencial biofertilizante

OpenAIRE

Lara Mantilla, Cecilia; García Támara, Liliana Pahola; Oviedo Zumaqué, Luis E

2010-01-01

En el presente trabajo se muestran los resultados obtenidos de la evaluación del crecimiento, desarrollo y viabilidad de una cepa bacteriana nativa Azotobacter A15M2G con potencial biofertilizante, sobre un medio de cultivo preparado con residuos sólidos vegetales procedentes del mercado: Brassica Oleracea (repollo), Lactusa sativa (lechuga) y Allium fistulosum (cebollín). El crecimiento de la bacteria en el medio de residuo vegetal a diferentes concentraciones: 25, 50 y 75% p/v fue evaluado,...

Kinetics and thermodynamics of the binding of riboflavin, riboflavin 5'-phosphate and riboflavin 3',5'-bisphosphate by apoflavodoxins.

OpenAIRE

Pueyo, J J; Curley, G P; Mayhew, S G

1996-01-01

The reactions of excess apoflavodoxin from Desulfovibrio vulgaris, Anabaena variabilis and Azotobacter vinelandii with ribo- flavin 5«-phosphate (FMN), riboflavin 3«,5«-bisphosphate and riboflavin are pseudo-first-order. The rates increase with decreasing pH in the range pH 5-8, and, in general, they increase with increasing ionic strength to approach a maximum at an ionic strength greater than 0.4 M. The rate of FMN binding in phosphate at high pH increases to a maximum ...

Effect of biological and chemical preparations on peroxidase activity in leaves of tomato plants

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Yulia Kolomiets

2016-10-01

Full Text Available In terms of treating tomato variety Chaika with chemical preparations with active substances if aluminum phosphate, 570 g/l + phosphorous acid 80 g/,l and mankotseb in concentration of 640 g/kg, the maximum increase in peroxidase activity in leaves of plants was observed in12 hours. In terms of use of biological preparations based on living cells Bacillus subtilis and Azotobacter chroococcum its activity was maximum in 24 hours and ranged from 77.7 to 112.7 un.mg-1•s-1

Development of a new biofertilizer with a high capacity for N2 fixation, phosphate and potassium solubilization and auxin production.

Science.gov (United States)

Leaungvutiviroj, Chaveevan; Ruangphisarn, Pimtida; Hansanimitkul, Pikul; Shinkawa, Hidenori; Sasaki, Ken

2010-01-01

Biofertilizers that possess a high capacity for N(2) fixation (Azotobacter tropicalis), and consist of phosphate solubilizing bacteria (Burkhoderia unamae), and potassium solubilizing bacteria (Bacillus subtilis) and produce auxin (KJB9/2 strain), have a high potential for growth and yield enhancement of corn and vegetables (Chinese kale). For vegetables, the addition of biofertilizer alone enhanced growth 4 times. Moreover, an enhancement of growth by 7 times was observed due to the addition of rock phosphate and K-feldspar, natural mineral fertilizers, in combination with the biofertilizer.

Efecto de la biofertilización y los biorreguladores en la germinación y el crecimiento de Carica papaya L.

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Maricela Constantino

2010-07-01

Full Text Available Título en inglés: Effect of biofertilization and bioregulators on germination and growth of Carica papaya L. Resumen Con el objetivo de incrementar y acelerar el proceso de germinación de las semillas y obtener una alta producción y homogeneidad de plántulas de Carica papaya variedad Maradol en vivero, se evaluó el efecto de tres biofertilizantes aplicados solos o en combinación (Azotobacter chroococcum, Azospirillum brasilense y Glomus intraradices, y un biorregulador del crecimiento vegetal, el ácido giberélico (AG3, en la germinación y el crecimiento vegetal. Se realizó un experimento bajo un diseño completamente al azar con ocho tratamientos y tres repeticiones. A las semillas se les aplicó un pretratamiento germinativo con alternancia de temperatura para superar la dormancia. Los tratamientos simples con A. chroococcum y A. brasilense, incrementaron el porcentaje de germinación a 90,28 y 88,89% respectivamente. Además, con la aplicación de los biofertilizantes y el AG3, la velocidad de germinación se incrementó y el tiempo medio de germinación se redujo. La doble aplicación en semillas y foliar de los biofertilizantes y el AG3 en plántulas mejoró el crecimiento vegetal. La población de A. chroococcum fue mayor cuando se inoculó en combinación con G. intraradices. La prevalencia de colonización de las plántulas inoculadas con G. intraradices varió de 18,53 a 26,67%, con el mayor valor registrado para el tratamiento combinado con A. brasilense. Finalmente, aplicando esta metodología se logró acelerar la germinación, obteniéndose una mayor homogeneidad en la emergencia de las plántulas, disminuyendo así el tiempo de permanencia en el vivero. Palabras clave: Azospirillum brasilense; Azotobacter chroococcum; Glomus intraradices; ácido giberélico; dormancia. Abstract In order to increase and accelerate the process of seed germination and obtain a high yield and homogeneity of papaya seedlings cv. Maradol in

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

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S. Dastborhan

2016-04-01

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

CARACTERIZACIÓN DE BACTERIAS DIAZOTRÓFICAS ASIMBIÓTICAS ASOCIADAS AL EUCALIPTO (Eucalyptus sp. EN CODAZZI, CESAR.

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Dolly Melissa Obando Castellanos

2010-09-01

Full Text Available Se evaluó el efecto de las épocas climáticas (lluvia y sequía y del estrato de la muestra (Suelo rizosférico, raíces y hojas sobre la población de los géneros Azotobacter, Beijerinckia, Derxia, Azospirillum, Herbaspirillum, Gluconacetobacter y Burkholderia en el Eucalipto (Eucalyptus sp.. Así mismo, se evalúo su capacidad en la producción de compuestos indólicos como promotores del crecimiento vegetal y su actividad de reducción de acetileno como indicador de la fijación biológica de nitrógeno. Los resultados no registraron diferencias estadísticas significativas en el test de Tukey (P ≤ 0.05 en la población con respecto a la época climática. Con respecto al estrato de muestra, los aislamientos tentativos a Herbaspirillum sp. y Azospirillum sp. presentaron diferencias significativas en suelo rizosférico y raíces. Se obtuvieron 44 aislamientos de los cuales se agruparon por caracterización fenotípica como: 14 presuntivos del género Beijerinckia sp., 12 de Azotobacter sp., 8 de Derxia sp., 4 de Herbarpirillum sp., 5 de Azospirillum sp., 1 de Gluconacetobacter sp. y 1 de Burkholderia sp. Por su alto potencial fueron seleccionados y criopreservados los aislamientos C27, C26, C25 y C45, las cuales presentaron los mejores valores de eficiencia in vitro, superando valores de producción de las cepas de referencia utilizadas (A. chroococcum (AC-01 y A. brasilense (SP7.

Effect of Biofertilizers on the Yield and Yield Components of Black Cumin (Nigella sativa L.

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S Khorramdel

2011-02-01

Full Text Available Abstract Application of biological fertilizers is one of the most important methods for plant nutrition in ecological agriculture. In order to investigate the effect of biofertilizers on yield and yield components of black cumin (Nigella sativa L., a field experiment was arranged in a randomized complete block design with three replications during 2007 growing season at the Agricultural Research Station of Ferdowsi University of Mashhad. Treatments included: (A Azotobacter paspali, (B Azospirillum brasilense, (C the fungus of Glomus intraradaices, C+A, C+B, A+B, A+B+C, and control without no biofertilizers. In all treatments except control, the amounts of 15 mg of each biofertilizer were applied to 110 g of seeds. Results indicated that application of biofertilizers enhanced yield and yield components and decreased percentage of hollow capsules. Plant performance was better with application of Azospirillum plus mycorrhiza and a mixture of Azotobacter, Azospirillum and mycorrhiza in terms of yield determining criteria. The maximum and minimum amounts of seed yield were recorded in the B+C treatment with 41.4 gm-2, and control with 24.1 gm-2, respectively. There was no significant correlation between number of capsules per plant and seed yield, but the positive and significant correlation between number of branches per plant, number of seeds per capsule, 1000-seed weight and seed yield was observed. This study showed that application of suitable biofertilizers could increase yield and yield components of black cumin. Keywords: Biofertilizer, Ecological agriculture, Medicinal plants, Plant growth promoting rhizobacteria

Alginato bacteriano: aspectos tecnológicos, características e produção Bacterial alginate: technological aspects, characteristics and production

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Crispin Humberto Garcia-Cruz

2008-01-01

Full Text Available Alginate is a biopolymer used for a variety of industrial applications, for example, in the textiles, cosmetics, foods, agricultural and biotechnological industries. This biopolymer is traditionally extracted from some brown seaweeds (Phaeophyceae and can be produced by bacteria isolated from soil, as Azotobacter vinelandii, like capsular polysaccharide using glucose, sucrose, among others as carbon sources. The main difference between the alginate of seaweed and the bacterial ones, is the biggest degree of acetylation of this last one, with great influence in the gel force. These chemical characteristics and production of bacterial alginate are presented in this work.

Nitrogen fixation and induction of pseudo-nodules in grass

International Nuclear Information System (INIS)

Rasul, G.; Hassan, U.; Mehnaz, S.; Malik, K.A.

1993-01-01

The rice grown nitrogen depleted saline sols showed higher values for in-situ ARA. Isolations of N/sub 2/ fixing bacteria were carried out on soil Azotobacter was observed in plant rhizosphere. The 2,4-D (0.5 and 1 ppm) with diazo trophic bacteria induced nodule like structure on the wheat roots. The bacteria were found in nodules in the form of micro colonies or bacterial aggregates which were responsible for nitrogen fixation providing optimum 02 concentrations was incorporations /sup 15/N dilution data indicated that 125-46.5% atmosphere N was incorporated in nitrogen pool of inoculated plants. (author)

Microbial flora associated with submerged mangrove leaf litter in India

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Narayanasamy Rajendran

2007-06-01

Full Text Available We studied the microbial flora in decomposing mangrove leaves in relation to changes in nitrogen and tannin levels, and in penaeid prawn assemblages. Senescent leaves of two mangrove species (Rhizophora apiculata and Avicennia marina kept in nylon bags, were separately immersed for 80 days in five tanks full of mangrove water. A known amount of decomposing leaves was collected every ten days from each tank for microorganism counts, total nitrogen and tannin measurement, and juvenile penaeid prawn counts. Five genera of total heterotrophic bacteria (THB, three species of azotobacters and 19 species of fungi were identified. The azotobacters showed a significant peak around 40-50 days after the beginning of of decomposition, similar to the trend for total nitrogen and for prawn assemblages. Rev. Biol. Trop. 55 (2: 393-400. Epub 2007 June, 29.Se estudió la flora microbiana en hojas en descomposición de mangles, considerando nitrógeno, taninos y camarones peneidos jóvenes. Colocamos hojas viejas de dos especies de mangle (Rhizophora apiculata y Avicennia marina en bolsas de nylon y las sumergimos en agua de manglar durante 80 días usando cinco tanques separados. Cada diez días extrajimos una cantidad conocida de hojas en descomposición de cada tanque. Hallamos cinco géneros de bacterias heterotróficas totales (THB, tres especies de azotobacterias y 19 especies de hongos. Las azotobacterias presentaron un pico significativo de abundancia alrededor de los 40-50 días de descomposición, un patrón similar a los del nitrógeno total y los camarones.

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

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P Rezvani Moghaddam

2015-07-01

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

Restoration of fly ash dump through biological interventions.

Science.gov (United States)

Juwarkar, Asha A; Jambhulkar, Hemlata P

2008-04-01

Field experiment on 10 ha area of fly ash dump was conducted to restore and revegetate it using biological interventions, which involves use of organic amendment, selection of suitable plant species along with specialized nitrogen fixing strains of biofertilizer. The results of the study indicated that amendment with farm yard manure at 50 t/ha improved the physical properties of fly ash such as maximum water holding capacity from 40.0 to 62.42% while porosity improved from 56.78 to 58.45%. The nitrogen content was increased by 4.5 times due to addition of nitrogen fixing strains of Bradyrhizobium and Azotobacter species, while phosphate content was increased by 10.0 times due to addition of VAM, which helps in phosphate immobilization. Due to biofertilizer inoculation different microbial groups such as Rhizobium, Azotobacter and VAM spores, which were practically absent in fly ash improved to 7.1 x 10(7), 9.2 x 10(7) CFU/g and 35 VAM spores/10 g of fly ash, respectively. Inoculation of biofertilizer and application of FYM helped in reducing the toxicity of heavy metals such as cadmium, copper, nickel and lead which were reduced by 25, 46, 48 and 47%, respectively, due to the increased organic matter content in the fly ash which complexes the heavy metals thereby decreasing the toxicity of metals. Amendment of fly ash with FYM and biofertilizer helped in profuse root development showing 15 times higher growth in Dendrocalamus strictus plant as compared to the control. Thus amendment and biofertilizer application provided better supportive material for anchorage and growth of the plant.

Survival of microorganisms in smectite clays - Implications for Martian exobiology

Science.gov (United States)

Moll, Deborah M.; Vestal, J. R.

1992-01-01

The survival of Baccillus subtilis, Azotobacter chroococcum, and the enteric bacteriophage MS2 has been examined in clays representing terrestrial (Wyoming type montmorillonite) and Martian (Fe3+ montmorillonite) soils exposed to terrestrial and Martian environmental conditions of temperature and atmospheric composition and pressure. An important finding is that MS2 survived simulated Mars conditions better than the terrestrial environment, probably owing to stabilization of the virus caused by the cold and dry conditions of the simulated Mars environment. This finding, the first published indication that viruses may be able to survive in Mars-type soils, may have important implications for future missions to Mars.

Aminoacid composition of wheat grain gluten under microbe impact

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Sokolova М. G.

2012-11-01

Full Text Available The study was focused on characteristics of gluten, protein and aminoacids content in wheat grain under the impact of microbe preparations including bacteria of Azotobacter and Bacillus geni, which inhabit plant rhizosphere. The increase of aminoacids leveland particularly the level of essential aminoacids in wheat grain under bacterization was demonstrated, this fact accounting for the quality of grain as an important protein source. Increase of aminoacids content with the use of biopreparations on low-fertile soil ensures acquisition of biologically valuable grain with the decrease of mineral fertilizers dosage and emphasizes the role of biopreparations in the production of ecologically pure high quality products. The latter is due to introdcution of environmentally safe agricultural methods.

The vanadium nitrogenase of Azotobacter chroococcum. Reduction of acetylene and ethylene to ethane.

Science.gov (United States)

Dilworth, M J; Eady, R R; Eldridge, M E

1988-01-01

1. The vanadium (V-) nitrogenase of Azobacter chroococcum transfers up to 7.4% of the electrons used in acetylene (C2H2) reduction for the formation of ethane (C2H6). The apparent Km for C2H2 (6 kPa) is the same for either ethylene (C2H4) or ethane (C2H6) formation and much higher than the reported Km values for C2H2 reduction to C2H4 by molybdenum (Mo-) nitrogenases. Reduction of C2H2 in 2H2O yields predominantly [cis-2H2]ethylene. 2. The ratio of electron flux yielding C2H6 to that yielding C2H4 (the C2H6/C2H4 ratio) is increased by raising the ratio of Fe protein to VFe protein and by increasing the assay temperature up to at least 40 degrees C. pH values above 7.5 decrease the C2H6/C2H4 ratio. 3. C2H4 and C2H6 formation from C2H2 by V-nitrogenase are not inhibited by H2. CO inhibits both processes much less strongly than it inhibits C2H4 formation from C2H2 with Mo-nitrogenase. 4. Although V-nitrogenase also catalyses the slow CO-sensitive reduction of C2H4 to C2H6, free C2H4 is not an intermediate in C2H6 formation from C2H2. 5. Propyne (CH3C identical to CH) is not reduced by the V-nitrogenase. 6. Some implications of these results for the mechanism of C2H6 formation by the V-nitrogenase are discussed. PMID:3162672

Expression, purification, crystallization and preliminary X-ray analysis of Pseudomonas aeruginosa AlgX

Energy Technology Data Exchange (ETDEWEB)

Weadge, J.T.; Robinson, H.; Yip, P. P.; Arnett, K.; Tipton, P. A.; Howell, P. L.

2010-05-01

AlgX is a periplasmic protein required for the production of the exopolysaccharide alginate in Pseudomonas sp. and Azotobacter vinelandii. AlgX has been overexpressed and purified and diffraction-quality crystals have been grown using iterative seeding and the hanging-drop vapor-diffusion method. The crystals grew as flat plates with unit-cell parameters a = 46.4, b = 120.6, c = 86.9 {angstrom}, {beta} = 95.7{sup o}. The crystals exhibited the symmetry of space group P2{sub 1} and diffracted to a minimum d-spacing of 2.1 {angstrom}. On the basis of the Matthews coefficient (V{sub M} = 2.25 {angstrom}{sup 3} Da{sup -1}), two molecules were estimated to be present in the asymmetric unit.

Bioaccumulation and phyto-translocation of arsenic, chromium and zinc by Jatropha curcas L.: impact of dairy sludge and biofertilizer.

Science.gov (United States)

Yadav, Santosh Kumar; Juwarkar, Asha A; Kumar, G Phani; Thawale, Prashant R; Singh, Sanjeev K; Chakrabarti, Tapan

2009-10-01

The present study was planned to remediate the metalloid and metal contaminated soil by using non-edible and economic plant species Jatropha curcas L. The experiment was conducted on pots to improve the survival rate, metal tolerance and growth response of the plant on soil; having different concentrations of arsenic, chromium and zinc. The soil was amended with dairy sludge and bacterial inoculum (Azotobacter chroococcum) as biofertilizer. The results of the study showed that the bioaccumulation potential was increased with increase in metalloid and metal concentration in soil system. Application of dairy sludge significantly reduces the DTPA-extractable As, Cr and Zn concentration in soil. The application of organic amendment stabilizes the As, Cr and Zn and reduced their uptake in plant tissues.

Effect of an insecticide on growth and metabolism of some non-target soil micro-organisms

International Nuclear Information System (INIS)

Balasubramanian, A.; Nilakantan, Gita

1975-01-01

Aldicarb, a systemic insecticide, enhanced the growth of Rhizobium japonicum in vitro at 1 ppm concentration but inhibited it at 5 ppm level. The cell yields of Azotobacter chroococcum and Pseudomonas solanacearum were reduced by both the concentrations of the chemical. 1 and 5 ppm levels of the insecticide the incorporation of 14 C-glucose by R. japonicum, but it was stimulated in the case of R. chroococcum. In the case of P. solanacearum, however, 1 ppm level of the insecticide enhanced the incorporation of the label. Uptake of 32 P-di-potassium hydrogen phosphate by the cells was also significantly reduced indicating that the metabolic activities of these non-target soil micro-organisms are altered by the insecticide treatment. (author)

Efecto de la fertilización en la nutrición y rendimiento de ají (Capsicum spp. en el Valle del Cauca, Colombia Effect of the fertilization on the nutrition and yield of the red pepper (Capsicum spp. in the Valley of the Cauca, Colombia.

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Edgar A Rodríguez Araujo

2010-01-01

Full Text Available En el estudio se evaluó el efecto de las fertilizaciones química y orgánica y biofertilización en la nutrición y rendimiento del ají (Capsicum spp. en el Valle del Cauca, Colombia, y en la producción de plántulas en vivero y en campo. Las variables evaluadas en vivero fueron: peso fresco de raíz y parte aérea, número de hojas, altura de la planta (cm, diámetro del tallo (mm, peso seco total, peso seco de raíz y parte aérea. Se evaluaron seis tratamientos, bajo un diseño estadístico de bloques completos al azar, de la forma siguiente: fertilización de síntesis química completa (testigo (FSQC, FSQC más fertilización orgánica (FSQC + O, FSQC + O más biofertilización 1 (solubilizador de fósforo con base en Penicillium janthinellum (1x10(7conidias/ml, FSQC + O más micorrizas (FSQC + O + M, FSQC + O más biofertilización 2 (fijador de nitrógeno con base en Azotobacter chroococcum (1x10(8 UFC/ml y Azospirillun sp. (1x10(8 UFC/ml, FSQC + O más biofertilización 3 (fijador de nitrógeno con base en Azotobacter chroococcum (1x10(8 UFC/ml. El experimento se instaló sobre un Typic Hapludolls. El análisis de resultados mostró que, en todos los tratamientos la fertilización de síntesis química + orgánica + micorrizas presentó los mejores resultados (P This study was realised with the purpose of to evaluate the effect of the chemical, organic fertilization and biofertilization on the nutrition and yield of the red pepper (Capsicum spp. in the Valley of the Cauca in the initial production of plants in breeding ground and final production in field. Two experiments were realized, one in stage of fish-pond and other one in field stage. In fish-pond an experiment was realized where there was evaluated the effect of the different types of fertilization in chili and other one where there was evaluated the effect of the chemical, organic fertilization and biofertilización in chili. In field there was evaluated the effect of the

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

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

2017-10-25

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

Effect of herbicides on microbiological properties of soil

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Milošević Nada A.

2002-01-01

Full Text Available Microorganisms decompose herbicides and they may serve as bioindicators of soil changes following herbicide application. Certain microbial species may be used as bioherbicides. This study has shown that Azotobacter is most sensitive to herbicide application; it is, therefore, a reliable indicator of the biological value of soil. The numbers of this group of nitrogen-fixing bacteria decrease considerably in the period of 7-14 days after herbicide application. Simultaneously, the numbers of Actinomycetes and less so of fungi increase, indicating that these microorganisms use herbicides as sources of biogenous elements. Rate of herbicidal decomposition depends on the properties of the preparation applied herbicide dose as well as on the physical and chemical soil properties, soil moisture and temperature, ground cover, agrotechnical measures applied and the resident microbial population.

A new player in the biorefineries field: phasin PhaP enhances tolerance to solvents and boosts ethanol and 1,3-propanediol synthesis in Escherichia coli

DEFF Research Database (Denmark)

Mezzina, Mariela P.; Álvarez, Daniela; Egoburo, Diego

2017-01-01

The microbial production of biofuels and other added-value chemicals is often limited by the intrinsic toxicity of these compounds. Phasin PhaP from the soil bacterium Azotobacter sp. strain FA8 is a polyhydroxyalkanoate granule-associated protein that protects recombinant Escherichia coli against...... as a strategy to increase tolerance to several biotechnologically relevant chemicals. PhaP was observed to enhance bacterial fitness in the presence of biofuels, such as ethanol and butanol, and to other chemicals, such as 1,3-propanediol. The effect of PhaP was also studied in a groELS mutant strain, in which...... and chemicals production.Importance. This work has both basic and applied aspects. Our results demonstrate that a phasin with chaperone-like properties can increase bacterial tolerance to several biochemicals, providing further evidence of the diverse properties of these proteins. Additionally, both the Pha...

Evaluating the biological activity of oil-polluted soils using a complex index

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Kabirov, R. R.; Kireeva, N. A.; Kabirov, T. R.; Dubovik, I. Ye.; Yakupova, A. B.; Safiullina, L. M.

2012-02-01

A complex index characterizing the biological activity of soils (BAS) is suggested. It is based on an estimate of the level of activity of catalase; the number of heterotrophic and hydrocarbon oxidizing microorganisms, microscopic fungi, algae, and cyanobacteria; and the degree of development of higher plants and insects in the studied soil. The data on using the BAS coefficient for evaluating the efficiency of rehabilitation measures for oil-polluted soils are given. Such measures included introducing the following biological preparations: Lenoil based on a natural consortium of microorganisms Bacillus brevis and Arthrobacter sp.; the Azolen biofertilizer with complex action based on Azotobacter vinelandii; the Belvitamil biopreparation, which is the active silt of pulp and paper production; and a ready-mixed industrial association of aerobic and anaerobic microorganisms that contains hydrocarbon oxidizing microorganisms of the Arthrobacter, Bacillus, Candida, Desulfovibrio, and Pseudomonas genera.

EFECTO DE LA BIOFERTILIZACIÓN SOBRE EL CRECIMIENTO EN MACETA DE PLANTAS DE CAÑA DE AZÚCAR (Saccharum officinarum EFEITO DA BIOFERTILIZAÇÃO NO CRESCIMENTO DE PLANTAS EM VASOS açúcar de cana (Saccharum officinarum EFFECT OF BIOFERTILIZATION ON THE GROWTH OF POTTED SUGARCANE PLANTS (Saccharum officinarum

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LILIANA SERNA-COCK

2011-12-01

Full Text Available El uso de microorganismos como fertilizante, ha demostrado tener efectos benéficos sobre el crecimiento de plantas y son una alternativa al uso de fertilizantes guímicos, sin embargo, cada microorganismo difiere en sus efectos benéficos. En este trabajo se evaluó el efecto de la aplicación de microorganismos fertilizantes, Azospirillum brasilense, Azotobacter chroccocum y Trichoderma lignorum sobre el crecimiento en maceta de plantas de caña de azúcar variedad CC 934418. El crecimiento de las plantas se midió en términos de diámetro del tallo, longitud de tallo y raíces, y número de hojas y raíces a los 15, 30 y 45 días de la siembra. El crecimiento de las plantas mostró diferencias estadísticamente significativas entre los tratamientos. Los microorganismos fertilizantes mostraron efecto positivo sobre el crecimiento de plantas de caña de azúcar, siendo Azospirillum brasilense y Trichoderma lignorum los microorganismos gue ejercieron mayor efecto sobre el diámetro del tallo y los sistemas radical y foliar de la planta. Se observaron los efectos beneficiosos de Trichoderma lignorum sobre el crecimiento de la hoja. Este es un nuevo aporte científico, ya que esta especie no ha sido reportada como promotora de crecimiento vegetal.0 uso de microrganismos como fertilizante, tem sido demonstrado gue têm efeitos benéficos no crescimento das plantas e são considerados uma alternativa ao uso de fertilizantes guímicos, no entanto, cada microrganismo possui diferentes efeitos benéficos. Neste estudo foi avaliado o efeito da aplicação de microorganismos fertilizantes, Azospirillum brasilense, Azotobacter chroccocum e Trichoderma lignorum no crescimento de cana-de-açucar da variedade CC 934418 plantadas em vasos. 0 crescimento das plantas foi medido em termos do diâmetro do caule, comprimento de caule e da raiz e número de folhas e raízes nos dias 15, 30 e 45 após a semeadura. 0 crescimento da planta mostrou diferen

Antibacterial activity of curcuma long varieties against different strains of bacteria

International Nuclear Information System (INIS)

Naz, S.; Jabeen, S.; Ilyas, S.; Aslam, F.; Manzoor, F.; Ali, A.

2010-01-01

Crude extracts of curcuminoids and essential oil of Curcuma long varieties Kasur, Faisalabad and Bannu were studied for their antibacterial activity against 4 bacterial strains viz., Bacillus subtilis, Bacillus macerans, Bacillus licheniformis and Azotobacter using agar well diffusion method. Solvents used to determine antibacterial activity were ethanol and methanol. Ethanol was used for the extraction of curcuminoids. Essential oil was extracted by hydrodistillation and diluted in methanol by serial dilution method. Both Curcuminoids and oil showed zone of inhibition against all tested strains of bacteria. Among all the three turmeric varieties, Kasur variety had the most inhibitory effect on the growth of all bacterial strains tested as compared to Faisalabad and Bannu varieties. Among all the bacterial strains B. subtilis was the most sensitive to turmeric extracts of curcuminoids and oil. The MIC value for different strains and varieties ranged from 3.0 to 20.6 mm in diameter. (author)

Isolation and Identification of Phosphate Solubilizing and Nitrogen Fixing Bacteria from Soil in Wamena Biological Garden, Jayawijaya, Papua

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SRI WIDAWATI

2005-07-01

Full Text Available A study was undertaken to investigate the occurrence of phosphate solubilizing bacteria (PSB and nitrogen-fixing bacteria (NFB from soil samples of Wamena Biological Garden (WbiG. Eleven soil samples were collected randomly to estimate microbial population which used plate count method. The result showed that the microbial population ranged from 5.0x103-7.5x106 cells of bacteria/gram of soil and 5.0x103-1.5x107 cells of bacteria/gram of soil for PSB and NFB respectively. There were 17 isolates which have been identified till genus and species. The isolated microorganism were identified as PSB i.e. Bacillus sp., B. pantothenticus, B. megatherium, Flavobacterium sp., F. breve, Klebsiella sp., K. aerogenes, Chromobacterium lividum, Enterobacter alvei, E. agglomerans, Pseudomonas sp., Proteus sp. and as NFB i.e. Azotobacter sp., A. chroococcum, A. paspalii, Rhizobium sp., and Azospirillum sp.

Effect of two organophosphorus insecticides on the growth, respiration and (/sup 14/C)-glucose metabolism of Azobacter chroococcum Beij

Energy Technology Data Exchange (ETDEWEB)

Balasubramanian, A; Narayanan, R [Tamil Nadu Agricultural Univ., Coimbatore (India)

1980-01-01

The two organophosphorus insecticides, commonly applied to soil, viz., disulfoton (0,0-diethyl S-2-ethyl thio ethyl phosphorodithioate) and fensulfothion (0,0-diethyl 0-4-methyl sulphinyl phenyl phosphorothioate) did not affect the in vitro growth of Azotobacter chroococcum Beij., the free-living, nitrogen fixing soil bacterium, at 2 ppm (lower level), while the normal dose (5 ppm) and the higher level (10 ppm) suppressed the growth. Respiration of the organism (glucose oxidation) was adversely affected by the insecticides in the growth medium and the inhibition increased with the concentration of the chemical. Both the insecticides suppressed the assimilation of (/sup 14/C)-glucose in the cold-TCA soluble, hot-TCA soluble fractions and insoluble residue of the cells whereas the /sup 14/C-incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that the insecticides considerably altered the glucose metabolism of the bacterium.

Effect of two organophosphorus insecticides on the growth, respiration and (14C)-glucose metabolism of Azobacter chroococcum Beij

International Nuclear Information System (INIS)

Balasubramanian, A.; Narayanan, R.

1980-01-01

The two organophosphorus insecticides, commonly applied to soil, viz., disulfoton (0,0-diethyl S-2-ethyl thio ethyl phosphorodithioate) and fensulfothion (0,0-diethyl 0-4-methyl sulphinyl phenyl phosphorothioate) did not affect the in vitro growth of Azotobacter chroococcum Beij., the free-living, nitrogen fixing soil bacterium, at 2 ppm (lower level), while the normal dose (5 ppm) and the higher level (10 ppm) suppressed the growth. Respiration of the organism (glucose oxidation) was adversely affected by the insecticides in the growth medium and the inhibition increased with the concentration of the chemical. Both the insecticides suppressed the assimilation of ( 14 C)-glucose in the cold-TCA soluble, hot-TCA soluble fractions and insoluble residue of the cells whereas the 14 C-incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that the insecticides considerably altered the glucose metabolism of the bacterium. (author)

Influence of bacteria on Pb and Zn speciation, mobility and bioavailability in soil: A laboratory study

International Nuclear Information System (INIS)

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

2006-01-01

A soil column experiment was carried out to investigate the effects of inoculation of bacteria on metal bioavailability, mobility and potential leachability through single chemical extraction, consequential extraction and in situ soil solution extraction technologies. Results showed that bacteria inoculated, including Azotobacter chroococcum, Bacillus megaterium and Bacillus mucilaginosus, may pose both positive and negative impacts on bioavailability and mobility of heavy metals in soil, depending on the chemical nature of the metals. The activities of bacteria led to an increase of water dissolved organic carbon (DOC) concentration and a decrease of pH value, which enhanced metal mobility and bioavailability (e.g. an increase of water-soluble and HOAc-soluble Zn). On the other hand, bacteria could immobilize metals (e.g. a great reduction of water-soluble Pb) due to the adsorption by bacterial cell walls and possible sedimentation reactions with phosphate or other anions produced through bacterial metabolism. - Influence of bacterial activities on heavy metal is two-edged

Bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting with Bacillus cereus HDYM-02.

Science.gov (United States)

Zhao, Dan; Liu, Pengfei; Pan, Chao; Du, Renpeng; Ping, Wenxiang; Ge, Jingping

2016-09-02

High-throughput sequencing and GC-MS (gas chromatography-mass spectrometry) were jointly used to reveal the bacterial succession and metabolite changes during flax (Linum usitatissimum L.) retting. The inoculation of Bacillus cereus HDYM-02 decreased bacterial richness and diversity. This inoculum led to the replacement of Enterobacteriaceae by Bacillaceae. The level of aerobic Pseudomonadaceae (mainly Azotobacter) and anaerobic Clostridiaceae_1 gradually increased and decreased, respectively. Following the addition of B. cereus HDYM-02, the dominant groups were all degumming enzyme producers or have been proven to be involved in microbial retting throughout the entire retting period. These results could be verified by the metabolite changes, either degumming enzymes or their catalytic products galacturonic acid and reducing sugars. The GC-MS data showed a clear separation between flax retting with and without B. cereus HDYM-02, particularly within the first 72 h. These findings reveal the important bacterial groups that are involved in fiber retting and will facilitate improvements in the retting process.

Biotechnological strategies to improve production of microbial poly-(3-hydroxybutyrate): a review of recent research work.

Science.gov (United States)

Peña, C; Castillo, T; García, A; Millán, M; Segura, D

2014-07-01

Poly-(3-hydroxybutyrate) [P(3HB)] is a polyester synthesized as a carbon and energy reserve material by a wide number of bacteria. This polymer is characterized by its thermo-plastic properties similar to plastics derived from petrochemical industry, such as polyethylene and polypropylene. Furthermore, P(3HB) is an inert, biocompatible and biodegradable material which has been proposed for several uses in medical and biomedical areas. Currently, only few bacterial species such as Cupriavidus necator, Azohydromonas lata and recombinant Escherichia coli have been successfully used for P(3HB) production at industrial level. Nevertheless, in recent years, several fermentation strategies using other microbial models such as Azotobacter vinelandii, A. chroococcum, as well as some methane-utilizing species, have been developed in order to improve the P(3HB) production and also its mean molecular weight. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Biodiversity of Bacteria Isolated from Different Soils

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Fatma YAMAN

2017-01-01

Full Text Available The aim of this study was to determine the biodiversity of PHB producing bacteria isolated from soils where fruit and vegetable are cultivated (onion, grape, olive, mulberry and plum in Aydın providence. Morphological, cultural, biochemical, and molecular methods were used for bacteria identification. These isolated bacteria were identified by 16S rRNA sequencing and using BLAST. The following bacteria Bacillus thuringiensis (6, Bacillus cereus (8, Bacillus anthrachis (1, Bacillus circulans (1, Bacillus weihenstephanensis (1, Pseudomonas putida (1, Azotobacter chroococcum (1, Brevibacterium frigoritolerans (1, Burkholderia sp. (1, Staphylococcus epidermidis (1, Streptomyces exfoliatus (1, Variovorax paradoxus (1 were found. The Maximum Likelihood method was used to produce a molecular phylogenetic analysis and a phylogenetic tree was constructed. These bacteria can produce polyhydroxybutyrate (PHB which is an organic polymer with commercial potential as a biodegradable thermoplastic. PHB can be used instead of petrol derivated non-degradable plastics. For this reason, PHB producing microorganisms are substantial in industry.

Composting of a crop residue through treatment with microorganisms and subsequent vermicomposting

Energy Technology Data Exchange (ETDEWEB)

Singh, A.; Sharma, S. [Indian Institute of Technology, New Delhi (India). Centre for Rural Development and Technology

2002-11-01

Preliminary studies were conducted on wheat straw to test the technical viability of an integrated system of composting, with bioinoculants and subsequent vermicomposting, to overcome the problem of lignocellulosic waste degradation, especially during the winter season. Wheat straw was pre-decomposed for 40 days by inoculating it with Pleurotus sajor-caju, Trichoderma harzianum, Aspergillus niger and Azotobacter chroococcum in different combinations. This was followed by vermicomposting for 30 days. Chemical analysis of the samples showed a significant decrease in cellulose, hemicellulose and lignin contents during pre-decomposition and vermicomposting. The N, P, K content increased significantly during pre-decomposition with bioinoculants. The best quality compost, based on chemical analysis, was prepared where the substrate was treated with all the four bioinoculants together followed by vermicomposting. Results indicated that the combination of both the systems reduced the overall time required for composting and accelerated the composting of ligno-cellulosic waste during the winter season besides producing a nutrient-enriched compost product. (author)

Biological remediation of oil contaminated soil with earthworms Eisenia andrei

Science.gov (United States)

Chachina, S. B.; Voronkova, N. A.; Baklanova, O. N.

2017-08-01

The study was performed on the bioremediation efficiency of the soil contaminated with oil (20 to 100 g/kg), petroleum (20 to 60 g/kg) and diesel fuel (20 to 40 g/kg) with the help of earthworms E. andrei in the presence of bacteria Pseudomonas, nitrogen fixing bacteria Azotobacter and Clostridium, yeasts Saccharomyces, fungi Aspergillus and Penicillium, as well as Actinomycetales, all being components of biopreparation Baykal-EM. It was demonstrated that in oil-contaminated soil, the content of hydrocarbons decreased by 95-97% after 22 weeks in the presence of worms and bacteria. In petroleum-contaminated soil the content of hydrocarbons decreased by 99% after 22 weeks. The presence of the diesel fuel in the amount of 40 g per 1 kg soil had an acute toxic effect and caused the death of 50 % earthworm species in 14 days. Bacteria introduction enhanced the toxic effect of the diesel fuel and resulted in the death of 60 % earthworms after 7 days.

Evaluation of some organic residues on the availability of nutrients to plants using nuclear technique

International Nuclear Information System (INIS)

Sayed, S.A.S

2006-01-01

Two pot experiments were carried out under greenhouse conditions in Soils and Water Research Department, Atomic Energy Authority.The aim of this work studies the effect of chicken manure and rice straw either separately or combined with mineral fertilizer by different rates pronounced the recommended dose (120 kg N fed -1 ) or half the recommended dose (60 kg N fed -1 + BF) on wheat plant grown in sandy soils. Organic materials were mixed with soil before packed in pots (5 kg soil pot1). Mineral fertilizer was added ( 15 N-labeled ammonium sulfate) after thinned wheat plants. The recommended basic supplemental doses of phosphorus and potassium fertilizers were applied to each pot. Wheat grains inoculated by Azotobacter chroococcum before cultivation in the second experiment. In addition to this work aimed the study affect of different fertilizer treatments on NPK of wheat plants as well as nitrogen derived from fertilizer (Ndff), soil (Ndfs), air (Ndfa) and fertilizer use efficiency (FUE) after the harvest of yield.

Functional participation of a nifH-arsA2 chimeric fusion gene in arsenic reduction by Escherichia coli

International Nuclear Information System (INIS)

Lahiri, Surobhi; Pulakat, Lakshmi; Gavini, Nara

2008-01-01

The NifH (dimer) and ArsA proteins are structural homologs and share common motifs like nucleotide-binding domains, signal transduction domains and also possible similar metal center ligands. Given the similarity between two proteins, we investigated if the NifH protein from Azotobacter vinelandii could functionally substitute for the ArsA1 half of the ArsA protein of Escherichia coli. The chimeric NifH-ArsA2 protein was expressed and detected in the E. coli strain by Western blotting. Growth comparisons of E. coli strains containing plasmids encoding for complete ArsA, partial ArsA (ArsA2) or chimeric ArsA (NifH-ArsA2) in media with increasing sodium arsenite concentrations (0-5 mM) showed that the chimeric NifH-ArsA2 could substitute for the ArsA. This functional complementation demonstrated the strong conservation of essential domains that have been maintained in NifH and ArsA even after their divergence to perform varied functions

Microbial Products and Biofertilizers in Improving Growth and Productivity of Apple - a Review.

Science.gov (United States)

Mosa, Walid F A E; Sas-Paszt, Lidia; Frąc, Mateusz; Trzciński, Paweł

2016-08-26

The excessive use of mineral fertilizers causes many negative consequences for the environment as well as potentially dangerous effects of chemical residues in plant tissues on the health of human and animal consumers. Bio-fertilizers are formulations of beneficial microorganisms, which upon application can increase the availability of nutrients by their biological activity and help to improve soil health. Microbes involved in the formulation of bio-fertilizers not only mobilize N and P but mediate the process of producing crops and foods naturally. This method avoids the use of synthetic chemical fertilizers and genetically modified organisms to influence the growth of crops. In addition to their role in enhancing the growth of the plants, biofertilizers can act as biocontrol agents in the rhizosphere at the same time. Biofertilizers are very safe for human, animal and environment. The use of Azotobacter, Azospirillum, Pseudomonas, Acetobacter, Burkholderia, Bacillus, Paenibacillus and some members of the Enterobacteriaceae is gaining worldwide importance and acceptance and appears to be the trend for the future.

Bioremediation of oil sludge using a type of nitrogen source and the consortium of bacteria with composting method

Science.gov (United States)

Fitri, Inayah; Ni'matuzahroh, Surtiningsih, Tini

2017-06-01

The purpose of this research are to know the effect of addition of different nitrogen source, consortium of bacteria, incubation time and the interaction between those variables to the total number of bacteria (CFU/g-soil) and the percentage of degradation (%) in the bioremediation of oil sludge contaminated soil; as well as degraded hydrocarbon components at the best treatment on 6th week. The experiments carried out by mixing the materials and placed them in each bath with and without adding different nitrogen source and bacterial consortium. pH and moisture were measured for every week. An increase in total number of bacteria and percent of maximum degradation recorded at treatment with the addition of NPK+Azotobacter+bacteria consortium; with the TPC value was 14.24 log CFU/g, percent degradation was 77.8%, organic C content was 10.91%, total N was 0.12% and organic matter content was 18.87%, respectively.

PERTUMBUHAN DAN PRODUKSI PADI SAWAH DAN GOGO DENGAN PEMBERIAN PUPUK HAYATI BERBASIS BAKTERI PEMACU TUMBUH DI TANAH MASAM

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Arie Aryanto

2015-12-01

Full Text Available Biofertilizer is a substance which contains microorganism and promotes plant growth by increasing the soil nutrient availability. The aim of this study was to analyze the growth and production of lowland and upland rice by using the biofertilizer in acid soils. Seven isolates of bacteria were used as biofertilizer, i.e. Bacillus sp., two strains of Pseudomonas sp., two strains of Azospirillum sp., and two strains of Azotobacter sp.. The treatments of this study were without fertilization, compost, 100% NPK, compost enriched with 7 isolates, compost enriched with 7 isolates + 50% NPK, compost enriched with 4 isolates, and compost enriched with 4 isolates + 50% NPK. The results showed that biofertilizer in compost improved nutrient content in acid soil, and increased rice growth and production as well. Compost enriched with 7 isolates 50% NPK showed the highest rice yield production both in the lowland and upland rice. The biofertilizer could reduced 50% utilization NPK fertilizer dosage in the first growing season.

Expression, Purification, Crystallization and Preliminary X-ray Analysis of Pseudomonas fluorescens AlgK

Energy Technology Data Exchange (ETDEWEB)

Keiski,C.; Yip, P.; Robinson, H.; Burrows, L.; Howell, P.

2007-01-01

AlgK is an outer-membrane lipoprotein involved in the biosynthesis of alginate in Pseudomonads and Azotobacter vinelandii. A recombinant form of Pseudomonas fluorescens AlgK with a C-terminal polyhistidine affinity tag has been expressed and purified from the periplasm of Escherichia coli cells and diffraction-quality crystals of AlgK have been grown using the hanging-drop vapour-diffusion method. The crystals grow as flat plates with unit-cell parameters a = 79.09, b = 107.85, c = 119.15 {angstrom}, = 96.97{sup o}. The crystals exhibit the symmetry of space group P2{sub 1} and diffract to a minimum d-spacing of 2.5 {angstrom} at Station X29 of the National Synchrotron Light Source, Brookhaven National Laboratory. On the basis of the Matthews coefficient (V{sub M} = 2.53 {angstrom}{sup 3} Da{sup -1}), four protein molecules are estimated to be present in the asymmetric unit.

Effects of biofertilizers on N-uptake (N-15) of corn (Zea mays L.) plant at early growth-stage

International Nuclear Information System (INIS)

Taufiq Bachtiar; Anggi Nico Flatian; Nurrobifahmi; Setiyo Hadi Waluyo

2016-01-01

Were studied in pot experiment at the green house in PAIR-BATAN. Broth culture of Azotobacter vinelandii (A), Bacillus cereus (B), Bacillus megaterium (C), and a mixture of those three microbes (ABC) were used as bio-fertilizers, and applied directly on plant grown in pots. Randomized Block Design (RBD) was used in this experiment with six treatments and four replicates. The measured parameters were nitrogen (N) uptake, N derived from the soil, N derived from fertilizer, and plant dry weight. These parameters were determined at 20 days after planting. N derived from bio-fertilizer and N derived from soil were determined by N-15 isotope technique. The results showed that ABC treatment most significantly increase the total N plant (142,42 %) and plant dry weight plant (129.03 %) by the control plant. Based on N-15 isotope technique analysis showed that the significantly contribution to increase N plant was found in ABC treatment (67.92 %). (author)

Estimation of the effect of radionuclide contamination on Vicia sativa L. induction of chlorophyll fluorescence parameters using "Floratest" optical biosensor

Science.gov (United States)

Ruban, Yu.; Illienko, V.; Nesterova, N.; Pareniuk, O.; Shavanova, K.

2017-12-01

The presented research was aimed to determine the parameters of chlorophyll fluorescence (IChH) curve induction for Vicia sativa L. that were grown on radionuclide contaminated soils by using "Floratest" fluorometer. Plants were inoculated with 5 species of bacteria that might potentially block radionuclide uptake (Agrobacterium radiobacter IMBB-7246, Azotobacter chroococcum UKMB-6082, A. chroococcum UKMB-6003, Bacillus megaterium UKMB-5724, Rhizobium leguminosarum bv. viceae) and grown in sod-podzolic, chernozem and peat-bog soils, contaminated with 137Cs (4000±340 Bq/kg). As a result of research, it was determined that the most stressful factors for vetch plants are combination of soil radionuclide and presence of Bacillus megaterium UKM B-5724, as the number of inactive chlorophyll increased. In addition, the vetch plants significantly increased fixed level of fluorescence (Fst) under the influence of radioactive contamination in presence of Bacillus megaterium UKM B-5724, indicating inhibition of photosynthetic reactions. Other bacteria showed radioprotective properties in almost all types of soil.

Microbial abundance in rhizosphere of medicinal and aromatic plant species in conventional and organic growing systems

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Adamović Dušan

2015-01-01

Full Text Available This study was aimed at comparing the abundance of microorganisms in the rhizosphere of four different medicinal and aromatic plant species (basil, mint, dill and marigold grown under both conventional and organic management on the chernozem soil at the experimental field of Bački Petrovac (Institute of Field and Vegetable Crops, Novi Sad, Serbia. Two sampling terms (June 1 and July 18, 2012 were performed to collect samples for microbiological analyses. The microbial abundance was higher in organic than in conventional system while at the same time significant differences were obtained only with dill rhizosphere. The differences in number of microorganisms belonging to different groups relied upon both plant species and sampling term. Thus, in mint, the recorded number of azotobacters and fungi was significantly higher whereas the number of ammonifiers was significantly lower. The present results indicate that organic growing system affected the abundance of microorganisms in rhizosphere of species investigated, especially in the second term of sampling.

Bio-chemical properties of sandy calcareous soil treated with rice straw-based hydrogels

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Houssni El-Saied

2016-06-01

The results obtained show that, application of the investigated hydrogels positively affects bio-chemical properties of the soil. These effects are assembled in the following: (a slightly decreasing soil pH, (b increasing cation exchange capacity (CEC of the soil indicating improvement in activating chemical reactions in the soil, (c increasing organic matter (OM, organic carbon, total nitrogen percent in the soil. Because the increase in organic nitrogen surpassed that in organic carbon, a narrower CN ratio of treated soils was obtained. This indicated the mineralization of nitrogen compounds and hence the possibility to save and provide available forms of N to growing plants, (d increasing available N, P and K in treated soil, and (e improving biological activity of the soil expressed as total count of bacteria and counts of Azotobacter sp., phosphate dissolving bacteria (PDB, fungi and actinomycetes/g soil as well as the activity of both dehydrogenase and phosphatase.

Assessment of free-living nitrogen fixing microorganisms for commercial nitrogen fixation. [economic analysis of ammonia production

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Stokes, B. O.; Wallace, C. J.

1978-01-01

Ammonia production by Klebsiella pneumoniae is not economical with present strains and improving nitrogen fixation to its theoretical limits in this organism is not sufficient to achieve economic viability. Because the value of both the hydrogen produced by this organism and the methane value of the carbon source required greatly exceed the value of the ammonia formed, ammonia (fixed nitrogen) should be considered the by-product. The production of hydrogen by KLEBSIELLA or other anaerobic nitrogen fixers should receive additional study, because the activity of nitrogenase offers a significant improvement in hydrogen production. The production of fixed nitrogen in the form of cell mass by Azotobacter is also uneconomical and the methane value of the carbon substrate exceeds the value of the nitrogen fixed. Parametric studies indicate that as efficiencies approach the theoretical limits the economics may become competitive. The use of nif-derepressed microorganisms, particularly blue-green algae, may have significant potential for in situ fertilization in the environment.

Fatty acids in an estuarine mangrove ecosystem

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Nabeel M Alikunhi

2010-06-01

Full Text Available Los ácidos grasos se han utilizado con éxito para estudiar la transferencia de materia orgánica en las redes alimentarias costeras y estuarinas. Para delinear las interacciones tróficas en las redes, se analizaron perfiles de ácidos grasos en las especies de microbios (Azotobacter vinelandii y Lactobacillus xylosus, camarones (Metapenaeus monoceros y Macrobrachium rosenbergii y peces (Mugil cephalus, que están asociadas con la descomposición de las hojas de dos especies de mangle, Rhizophora apiculata y Avicennia marina. Los ácidos grasos, con excepción de los de cadena larga, exhiben cambios durante la descomposición de las hojas de mangle, con una reducción de los ácidos grasos saturados y un aumento de los monoinsaturados. Los ácidos grasos ramificados están ausentes en las hojas de mangle sin descomponer, pero presentes de manera significativa en las hojas descompuestas, en camarones y peces, representando una fuente importante para ellos. Esto revela que los microbios son productores dominantes que contribuyen significativamente con los peces y camarones en el ecosistema de manglar. Este trabajo demuestra que los marcadores biológicos de los ácidos grasos son una herramienta eficaz para la identificación de las interacciones tróficas entre los productores dominantes y consumidores en este manglar.Fatty acids have been successfully used to trace the transfer of organic matter in coastal and estuarine food webs. To delineate these web connections, fatty acid profiles were analyzed in species of microbes (Azotobacter vinelandii, and Lactobacillus xylosus, prawns (Metapenaeus monoceros and Macrobrachium rosenbergii and finfish (Mugil cephalus, that are associated with decomposing leaves of two mangrove species, Rhizophora apiculata and Avicennia marina. The fatty acids, except long chain fatty acids, exhibit changes during decomposition of mangrove leaves with a reduction of saturated fatty acids and an increase of

Tubulinlike protein from Spirochaeta bajacaliforniensis

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Bermudes, D.; Fracek, S. P. Jr; Laursen, R. A.; Margulis, L.; Obar, R.; Tzertzinis, G.

1987-01-01

Tubulin proteins are the fundamental subunits of all polymeric microtubule-based eukaryotic structures. Long, hollow structures each composed of 13 protofilaments as revealed by electron microscopy, microtubules (240 angstroms in diameter) are nearly ubiquitous in eukaryotes. These proteins have been the subject of intense biochemical and biophyiscal interest since the early 1970s and are of evolutionary interest as well. If tubulin-based structures (i.e., neurotubules, mitotic spindle tubules, centrioles, kinetosomes, axonemes, etc.) evolved from spirochetes by way of motility symbioses, tubulin homologies with spirochete proteins should be detectable. Tubulin proteins are widely thought to be limited to eukaryotes. Yet both azotobacters and spirochetes have shown immunological cross-reactivity with antitubulin antibodies. In neither of these studies was tubulin isolated nor any specific antigen identified as responsible for the immunoreactivity. Furthermore, although far less uniform in structure than eukaryotic microtubules, various cytoplasmic fibers and tubules (as seen by electron microscopy) have been reported in several types of prokaryotes (e.g., Spirochaeta; large termite spirochetes; treponemes; cyanobacteria; and Azotobacter. This work forms a part of our long-range study of the possible prokaryotic origin of tubulin and microtubules. Spirochetes are helically shaped gram-negative motile prokaryotes. They differ from all other bacterial in that the position of their flagella is periplasmic: their flagella lie between the inner and outer membranes of the gram-negative cell wall. Some of the largest spirochetes have longitudinally aligned 240 angstrom microtubules. Unfortunately, in spite of many attempts, all of the larger spirochetes (family Pillotaceae) with well-defined cytoplasmic tubules and antitubulin immunoreactivity are not cultivable. However, a newly described spirochete species (Spirochaeta bajacaliforniensis) possessing cytoplasmic fibers

Efecto de la fertilización en la nutrición y rendimiento de ají (Capsicum spp. en el Valle del Cauca, Colombia

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Edgar A Rodríguez Araujo

2010-01-01

Full Text Available En el estudio se evaluó el efecto de las fertilizaciones química y orgánica y biofertilización en la nutrición y rendimiento del ají (Capsicum spp. en el Valle del Cauca, Colombia, y en la producción de plántulas en vivero y en campo. Las variables evaluadas en vivero fueron: peso fresco de raíz y parte aérea, número de hojas, altura de la planta (cm, diámetro del tallo (mm, peso seco total, peso seco de raíz y parte aérea. Se evaluaron seis tratamientos, bajo un diseño estadístico de bloques completos al azar, de la forma siguiente: fertilización de síntesis química completa (testigo (FSQC, FSQC más fertilización orgánica (FSQC + O, FSQC + O más biofertilización 1 (solubilizador de fósforo con base en Penicillium janthinellum (1x10(7conidias/ml, FSQC + O más micorrizas (FSQC + O + M, FSQC + O más biofertilización 2 (fijador de nitrógeno con base en Azotobacter chroococcum (1x10(8 UFC/ml y Azospirillun sp. (1x10(8 UFC/ml, FSQC + O más biofertilización 3 (fijador de nitrógeno con base en Azotobacter chroococcum (1x10(8 UFC/ml. El experimento se instaló sobre un Typic Hapludolls. El análisis de resultados mostró que, en todos los tratamientos la fertilización de síntesis química + orgánica + micorrizas presentó los mejores resultados (P < 0.01, seguido de los tratamientos a los que se aplicó la fuente de biofertilización (microorganismos solubilizadores de fósforo y fijadores de nitrógeno. Para los suelos estudiados se concluyó que el mayor rendimiento de ají se consigue cuando se aplica al suelo una fuente química completa, más una fuente de materia orgánica, más micorrizas arbusculares. Además, que la biofertilización es un complemento de la fertilización química.

EFECTO DE INOCULACIÓN DE MICROORGANISMOS EN CRECIMIENTO DE RÁBANO (Raphanus sativus EFEITO DA INOCULAÇÃO MICRORGANISMOS NO CRESCIMENTO DE RABANETE (Raphanus sativus EFFECT OF INOCULATION OF MICROORGANISMS ON RADISH GROWTH (Raphanus sativus

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LUZ INDIRA SOTELO D

2012-06-01

Full Text Available El efecto de la inoculación de microorganismos que pueden estimular el crecimiento en plantas, ha sido de gran interés para la producción de bioinsumos en los últimos años. Se inocularon cepas de Azotobacter sp, Bacillus pumilus y Bacillus licheniformis en un cultivo de rábano (Raphanus sativus, aisladas e identificadas de un proceso de compostaje de la empresa (GEO ®. Se realizó un diseño experimental de cinco tratamientos y un control, con 15 repeticiones para cada uno. Previo a la aplicación de los tratamientos cada cepa se sometió individualmente a crecimiento en caldo de cultivo. La aplicación de cada tratamiento se efectuó dos veces por aspersión, con un intervalo de 15 días durante el tiempo de cultivo. Las variables de respuesta que se evaluaron en el cultivo de rábano fueron: longitud de las plantas, número de hojas y peso seco del sistema radicular. Los resultados mostraron menor efectividad en la producción de biomasa radicular en el tratamiento T5 (mezcla de los tres microorganismos; además se encontró un mayor rendimiento en todas las variables de respuesta, con la utilización de la fertllización química. Sin embargo los tres microorganismos aplicados individualmente presentan resultados promisorios para la aplicación en cultivos agrícolas de ciclo corto.O efeito da inoculação de microrganismos que podem estimular o crescimento em plantas tem sido de grande interesse para a produção de bio-produtos nos últimos anos. Isolados foram inoculados Azotobacter sp, Bacillus pumilus e Bacillus licheniformis em uma cultura de rabanete (Raphanus sativus isolados e identificados em um processo de compostagem da empresa (GEO ®. Foi realizado um delineamento experimental de cinco tratamentos e controle, com 15 repetições para cada um. Antes da aplicação dos tratamentos, cada cepa foi submetida ao crescimento individual em caldo. A aplicação de cada tratamento foi realizada por aspersão duas vezes com um

VTVH-MCD study of the Delta nifB Delta nifZ MoFe protein from Azotobacter vinelandii.

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Cotton, Marcia S; Rupnik, Kresimir; Broach, Robyn B; Hu, Yilin; Fay, Aaron W; Ribbe, Markus W; Hales, Brian J

2009-04-08

NifZ is a member of a series of proteins associated with the maturation of the nitrogenase MoFe protein. An MCD spectroscopic study was undertaken on the Delta nifB Delta nifZ MoFe protein generated in the absence of both NifZ and NifB (deletion of NifB generates an apo-MoFe protein lacking the FeMo cofactor). Results presented here show that, in the absence of NifZ, only one of the two P-clusters of the MoFe protein is matured to the ultimate [8Fe-7S] structure. The other P-cluster site in the protein contains a [4Fe-4S] cluster pair, representing a P-cluster precursor that is electronically identical to the analogous clusters observed in the Delta nifH MoFe protein. These results suggest that the MoFe protein is synthesized in a stepwise fashion where NifZ is specifically required for the formation of the second P-cluster.

The influence of benefit microorganisms on yield and quality of soybean grains under conditions of reduced nitrogen fertilization

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Suzana Kristek

2017-01-01

Full Text Available The aim of this study was to investigate the possibility to reduce the application of mineral nitrogen fertilizers through the application of beneficial microorganisms (genus Bradyrhizobium, Azotobacter, bacteria Pseudomonas fluorescens, Bacillus spp., etc.. Research was conducted during 2013 and 2014 on Eutric brown soil. The experiment was set up in a split-block scheme with 12 different variants in 4 repetitions: two soybean cultivars were used; two different treatments of nitrogen fertilizers and three different treatments of microbiological preparation were applied. Analysed parameters were soybean grain yield (kg/ha based on 13% moisture, protein content (%, oil content (% and hectolitre mass (kg. Given that the climatic conditions in the second year of research were more favourable than in the first year of research, all the elements of research, including control variants, achieved better results in the second year of research. All variants treated with microbiological preparations, either by application in soil or by application in soil combined with foliar treatments, also achieved statistically significant differences compared to the control variants.

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

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Kumar Manoj

2015-01-01

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

Microbial Nitrogen-Cycle Gene Abundance in Soil of Cropland Abandoned for Different Periods.

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Huhe; Borjigin, Shinchilelt; Buhebaoyin; Wu, Yanpei; Li, Minquan; Cheng, Yunxiang

2016-01-01

In Inner Mongolia, steppe grasslands face desertification or degradation because of human overuse and abandonment after inappropriate agricultural management. The soils in these abandoned croplands exist in heterogeneous environments characterized by widely fluctuating microbial growth. Quantitative polymerase chain reaction analysis of microbial genes encoding proteins involved in the nitrogen cycle was used to study Azotobacter species, nitrifiers, and denitrifiers in the soils from steppe grasslands and croplands abandoned for 2, 6, and 26 years. Except for nitrifying archaea and nitrous oxide-reducing bacteria, the relative genotypic abundance of microbial communities involved in nitrogen metabolism differed by approximately 2- to 10-fold between abandoned cropland and steppe grassland soils. Although nitrogen-cycle gene abundances varied with abandonment time, the abundance patterns of nitrogen-cycle genes separated distinctly into abandoned cropland versus light-grazing steppe grassland, despite the lack of any cultivation for over a quarter-century. Plant biomass and plant diversity exerted a significant effect on the abundance of microbial communities that mediate the nitrogen cycle (P nitrogen cycle in recently abandoned croplands.

Nitrogen Released From Organic Residues Using 15N

International Nuclear Information System (INIS)

Galal, Y.G.M.; Gadalla, A.M.; Abdel Aziz, H.A.; Abdel Salam, A.A.; El-Degwy, S.M.A.

2008-01-01

Incubation technique was followed under laboratory condition to evaluate and determine the rate of organic residues decomposition as well as N released in media. Rice straw, soybean straw, and leuceana cutting residue were used. These materials were incubated on virgin sandy soil up to 90 days intervals. Cups with mixture of sand and organic residues were inoculated with fungi, bacteria and mixture of them. Un inoculated treatment was also included. Results showed that N released from the different organic materials was significant at 30 days of incubation. It seems that presence of Azotobacter was associated with enhanced demand on soluble N at this stage. Superiority of leucaena over the other two sources of rice straw and soybean straw occurred particularly during the 15 to 30.day period. In greenhouse experiment, the results indicated that N derived from organic materials was high and easily released from compost as mediated materials comparing to leucaena as undigested raw materials. In the same time, barley had more benefits from organic residues than lupine crop

Capsule production by Pseudomonas aeruginosa

Energy Technology Data Exchange (ETDEWEB)

Lynn, A.R.

1984-01-01

Mucoid strains of Pseudomonas aeruginosa, associated almost exclusively with chronic respiratory infections in patients with cystic fibrosis, possess a capsule composed of alginic acid similar to one produced by Azotobacter vinelandii. Recent reports have provided evidence that the biosynthetic pathway for alginate in P. aeruginosa may differ from the pathway proposed for A. vinelandii in that synthesis in P. aeruginosa may occur by way of the Entner-Doudoroff pathway. Incorporation of isotope from (6-/sup 14/C)glucose into alginate by both P. aueroginosa and A. vinelandii was 10-fold greater than that from either (1-/sup 14/C)/sup -/ or (2-/sup 14/C)glucose, indicating preferential utilization of the bottom half of the glucose molecule for alginate biosynthesis. These data strongly suggest that the Entner-Doudoroff pathway plays a major role in alginate synthesis in both P. aeruginosa and A. vinelandii. The enzymes of carbohydrate metabolism in mucoid strains of P. aeruginosa appear to be unchanged whether alignate is actively produced or not and activities do not differ significantly from nonmucoid strain PAO.

[Rice endogenous nitrogen fixing and growth promoting bacterium Herbaspirillum seropedicae DX35].

Science.gov (United States)

Wang, Xiucheng; Cao, Yanhua; Tang, Xue; Ma, Xiaotong; Gao, Jusheng; Zhang, Xiaoxia

2014-03-04

To screen efficient nitrogen fixation endophytes from rice and to analyze their growth-promoting properties. We isolated strains from the roots of rice in the field where it has a rice-rice-green manure rotation system for 30 years. Efficient strains were screened by acetylene reduction assay. Phylogenetic analysis is based on 16S rRNA gene, nifH gene and the composition of fatty acid. In addition, we also detected the ability of indole acetic acid secretion through the Salkowski colorimetric method, measured the production of siderophore through the blue plate assay and detected phosphate solubilization, to analyze the growth-promoting properties. A total of 48 strains were isolated, in which DX35 has the highest nitrogenase activity. It belongs to Herbaspirillum seropedicae after identification. Its nitrogenase activity (181.21 nmol C2H4/(mg protein x h)) was 10 times as much as the reference strain Azotobacter chroococcum ACCC10006. In addition, it also can secrete siderophore and solubilize phosphorus. Strain DX35, belonging to Herbaspirillum seropedicae, is an efficient nitrogen fixation endophytes.

Alginate Production from Alternative Carbon Sources and Use of Polymer Based Adsorbent in Heavy Metal Removal

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Çiğdem Kıvılcımdan Moral

2016-01-01

Full Text Available Alginate is a biopolymer composed of mannuronic and guluronic acids. It is harvested from marine brown algae; however, alginate can also be synthesized by some bacterial species, namely, Azotobacter and Pseudomonas. Use of pure carbohydrate sources for bacterial alginate production increases its cost and limits the chance of the polymer in the industrial market. In order to reduce the cost of bacterial alginate production, molasses, maltose, and starch were utilized as alternative low cost carbon sources in this study. Results were promising in the case of molasses with the maximum 4.67 g/L of alginate production. Alginates were rich in mannuronic acid during early fermentation independent of the carbon sources while the highest guluronic acid content was obtained as 68% in the case of maltose. The polymer was then combined with clinoptilolite, which is a natural zeolite, to remove copper from a synthetic wastewater. Alginate-clinoptilolite beads were efficiently adsorbed copper up to 131.6 mg Cu2+/g adsorbent at pH 4.5 according to the Langmuir isotherm model.

Aromatic plants play an important role in promoting soil biological activity related to nitrogen cycling in an orchard ecosystem.

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Chen, Xinxin; Song, Beizhou; Yao, Yuncong; Wu, Hongying; Hu, Jinghui; Zhao, Lingling

2014-02-15

Aromatic plants can substantially improve the diversity and structure of arthropod communities, as well as reduce the number of herbivore pests and regulate the abundance of predators and parasitoids. However, it is not clear whether aromatic plants are also effective in improving soil quality by enhancing nutrient cycling. Here, field experiments are described involving intercropping with aromatic plants to investigate their effect on soil nitrogen (N) cycling in an orchard ecosystem. The results indicate that the soil organic nitrogen and available nitrogen contents increased significantly in soils intercropped with aromatic plants. Similarly, the activities of soil protease and urease increased, together with total microbial biomass involved in N cycling, including nitrifying bacteria, denitrifying bacteria and azotobacters, as well as the total numbers of bacteria and fungi. This suggests that aromatic plants improve soil N cycling and nutrient levels by enriching the soil in organic matter through the regulation of both the abundance and community structure of microorganisms, together with associated soil enzyme activity, in orchard ecosystems. Copyright © 2013 Elsevier B.V. All rights reserved.

Microorganismos benéficos como biofertilizantes eficientes para el cultivo del tomate (Lycopersicon esculentum, Mill Beneficial microorganisms as efficient biofertilisers for tomato crops (Lycopersicon esculentum, Mill

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Hernández Annia

2005-12-01

Full Text Available En el uso y manejo de biofertilizantes en la agricultura, uno de los principales problemas es el desconocimiento de las especies presentes en los agroecosistemas y en la rizosfera de los cultivos, para su posible utilización eficiente. Desde el punto de vista ecológico, es importante conocer los integrantes de la comunidad bacteriana que favorecen su aplicación como inoculantes y propician un efecto agrobiológico positivo en los cultivos agrícolas. Esta investigación se desarrolló con el objetivo de evaluar la efectividad agrobiológica de Azospirillum sp, en el crecimiento, desarrollo y rendimiento en el cultivo del tomate. Para ello, se partió de seleccionar el género microbiano predominante en la rizosfera del cultivo y posteriormente se evaluó el efecto de su inoculación a partir de la respuesta del cultivo. Los resultados demostraron que los géneros Pseudomonas, Azospirillum, Azotobacter, Bacillus y Streptomyces, forman parte de la comunidad microbiana de la rizosfera del tomate, en las condiciones estudiadas, y que Azospirillum es el género dominante. La inoculación artificial de esta rizobacteria causó un efecto positivo sobre el crecimiento de las plántulas, así como en el estado nutricional de las plantas, con un rendimiento agrícola superior a un 11 % con respecto a las plantas testigo. Se obtuvo un alto nivel poblacional en la rizosfera de las plantas inoculadas. Palabras clave: rizosfera, inoculante, crecimiento, rendimiento.One of the main problems regarding the efficient use and management of biofertilizers in agriculture lies in the unknown species present in agro-ecosystems and crop rhizospheres. From the ecological point of view, it is important to know the members of the bacterial population allowing them to be applied as inoculants and enable a positive agro-biological effect on agricultural crops. This investigation was aimed at evaluating the agro-biological effectiveness of Azospirillum sp. on tomato

Evaluation of gene expression and alginate production in response to oxygen transfer in continuous culture of Azotobacter vinelandii.

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Alvaro Díaz-Barrera

Full Text Available Alginates are polysaccharides used as food additives and encapsulation agents in biotechnology, and their functional properties depend on its molecular weight. In this study, different steady-states in continuous cultures of A. vinelandii were established to determine the effect of the dilution rate (D and the agitation rate on alginate production and expression of genes involved in alginate polymerization and depolymerization. Both, the agitation and dilution rates, determined the partitioning of the carbon utilization from sucrose into alginate and CO2 under oxygen-limiting conditions. A low D (0.07 h(-1 and 500 rpm resulted in the highest carbon utilization into alginate (25%. Quantitative real-time polymerase chain reaction was used to determine the transcription level of six genes involved in alginate polymerization and depolymerization. In chemostat cultures at 0.07 h(-1, the gene expression was affected by changes in the agitation rate. By increasing the agitation rate from 400 to 600 rpm, the algE7 gene expression decreased tenfold, whereas alyA1, algL and alyA2 gene expression increased between 1.5 and 2.8 times under similar conditions evaluated. Chemostat at 0.07 h(-1 showed a highest alginate molecular weight (580 kDa at 500 rpm whereas similar molecular weights (480 kDa were obtained at 400 and 600 rpm. The highest molecular weight was not explained by changes in the expression of alg8 and alg44 (genes involved in alginate polymerization. Nonetheless, a different expression pattern observed for lyases could explain the highest alginate molecular weight obtained. Overall, the results suggest that the control of alginate molecular weight in A. vinelandii cells growing in continuous mode is determined by a balance between the gene expression of intracellular and extracellular lyases in response to oxygen availability. These findings better our understanding of the biosynthesis of bacterial alginate and help us progress toward obtain tailor-made alginates.

Microbial Nitrogen-Cycle Gene Abundance in Soil of Cropland Abandoned for Different Periods.

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Huhe

Full Text Available In Inner Mongolia, steppe grasslands face desertification or degradation because of human overuse and abandonment after inappropriate agricultural management. The soils in these abandoned croplands exist in heterogeneous environments characterized by widely fluctuating microbial growth. Quantitative polymerase chain reaction analysis of microbial genes encoding proteins involved in the nitrogen cycle was used to study Azotobacter species, nitrifiers, and denitrifiers in the soils from steppe grasslands and croplands abandoned for 2, 6, and 26 years. Except for nitrifying archaea and nitrous oxide-reducing bacteria, the relative genotypic abundance of microbial communities involved in nitrogen metabolism differed by approximately 2- to 10-fold between abandoned cropland and steppe grassland soils. Although nitrogen-cycle gene abundances varied with abandonment time, the abundance patterns of nitrogen-cycle genes separated distinctly into abandoned cropland versus light-grazing steppe grassland, despite the lack of any cultivation for over a quarter-century. Plant biomass and plant diversity exerted a significant effect on the abundance of microbial communities that mediate the nitrogen cycle (P < 0.002 and P < 0.03, respectively. The present study elucidates the ecology of bacteria that mediate the nitrogen cycle in recently abandoned croplands.

ISOLATION AND CHARACTERISTIC OF NITROGEN-FIXING BACTERIA AND PHOSPHATE-SOLUBILIZING BACTERIA FROM SOIL HIGH IN MERCURY IN TAILINGS AND COMPOST AREAS OF ARTISANAL GOLD MINE

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Yulia Nuraini

2015-02-01

Full Text Available The research was conducted at Brawijaya University and West Nusa Tenggara, from March 2013 to October 2013. The tailings areas of the gold mine contains high mercury (Hg as much as 1,090 ppm, and living microbes (resistance exist in a small number in such a condition. Microbial P solvents encountered came from the genus Bacillus with a population of 23 x 103 cfu g-1 and N-fixing bacteria encountered are of the genus Bacillus, with a population of 4 x 103 cfu g-1. Identification of species using Becton Dickinson Phoenix test, both species belong to Bacillus megaterium and Bacillus pumilus. While the waste corn and peanuts that has been composted for 4 weeks acquired P-solubilizing bacteria, such as Enterobacter, Bacillus and Pseudomonas, and N-fixing bacteria found was Pseudomonas and Azotobacter. While testing the activity and antagonism of N-fixing and P-solubilizing bacteria, the result on agar media did not show antagonism in its growth. Bacillus pumilus and Bacillus megaterium effective at 5 % molasses medium with the number of 0.15 x 1012 on seven days of incubation.

Full-scale photobioreactor for biotreatment of olive washing water: Structure and diversity of the microalgae-bacteria consortium.

Science.gov (United States)

Maza-Márquez, P; González-Martínez, A; Rodelas, B; González-López, J

2017-08-01

The performance of a full-scale photobioreactor (PBR) for the treatment of olive washing water (OWW) was evaluated under different HRTs (5-2days). The system was able to treat up to 3926L OWWday -1 , and consisted of an activated-carbon pretreatment column and a tubular PBR unit (80 tubes, 98.17L volume, 2-m height, 0.25m diameter). PBR was an effective and environmentally friendly method for the removal of phenols, COD, BOD 5 , turbidity and color from OWW (average efficiencies 94.84±0.55%, 85.86±1.24%, 99.12±0.17%, 95.86±0.98% and 87.24±0.91%, respectively). The diversity of total bacteria and microalgae in the PBR was analyzed using Illumina-sequencing, evaluating the efficiency of two DNA extraction methods. A stable microalgae-bacteria consortium was developed throughout the whole experimentation period, regardless of changes in HRT, temperature or solar radiation. MDS analyses revealed that the interplay between green algae (Sphaeropleales), cyanobacteria (Hapalosiphon) and Proteobacteria (Rhodopseudomonas, Azotobacter) played important roles in OWW bioremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluate of Some Germination and Emergence Characteristics of Fennel (foeniculum vulgare Mill Producted from Seeds under Application Organic and Biological Fertilizers

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M.B Amiri

2013-04-01

Full Text Available In order to study the effects of manure and biofertilizers application that were applied on parent plants, on the germination and emergence indices of produced seeds of fennel, two laboratory and greenhouse experiments based on completely randomized design with four replications were conducted in Ferdowsi University of Mashhad, Iran. Treatments were consisted of 11 different seed types that were produced on parent plants fed by: Compost (C, Vermicompost (V, Azotobacter (A, Pseudomonas (P, A+C, C+P, C+V, P+A, P+V, V+A and Control. Results of greenhouse study revealed that most studied treatments were effective on the height of fennel. Moreover, V and C+P treatments were superior in terms of emergence percentage and aerial dry weight, respectively. Results of laboratory experiment showed that C+V treatment were superior to other treatments in terms of germination percentage, germination rate, germination index and mean germination time. Overall, the experimental findings revealed that seed producing by manure and biofertilizers utilization on parent plants is a suitable method for production of organic seeds that have optimal germination and early seedling growth indices.

Efficient Use of Organic Sources by Sorghum Plants Grown on Sand Soil Using "1"5N Stable Isotope Technique

International Nuclear Information System (INIS)

EL Hassanin, A.S; Khalifa, A.M; Abdel Aziz, H.A; Galal, Y.G.M; Abdel Salam, M.F

2015-01-01

A green house experiment was conducted at Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Inshas, Egypt. Different organic/bio fertilizer and mineral fertilizers were existed for detection and evaluation of sorghum crop response when grown on sand soils. Mineral fertilizer in the form of labeled ammonium sulfate with 2% "1"5N atom excess was applied at two rates of 200 and 400 mg N pot-1 and unfertilized control treatment also included. Different organic fertilizers such as compost, chicken manure and leucaena residues were applied at the same rates per pot according to its content of nitrogen. Sorghum plants treated with organic or mineral fertilizers were inoculated with Azotobacter chrooccocum as a representative of associative nitrogen fixing microorganisms. Un inoculated plants were also included. Completely randomized block design was followed for statistical analysis. Nitrogen use efficiency (%NUE) was estimated using the portion of N derived from mineral fertilizer. Experimental data released from this work could be summarized as following: Dry matter yield of stalks and roots were increased with increasing mineral fertilizer rates where the best increments detected at 100% N rate as compared to the unfertilized control

Endophytes in commercial micropropagation - friend or foe?

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Rödel, Philipp

2016-07-01

Full Text Available Medicinal and aromatic plants are superorganisms like all plant species- naturally colonized by bacteria, fungi and protists. Micropropagated plants are facing different challenges under in vitro and ex vitro conditions: Mixotrophic growth under low light conditions on artificial nutrient media, poor gas exchange in small vessels, abiotic stress, bad rooting, transplanting stress, low survival rate during acclimatization in greenhouse. The use of endophytes in micropropagation can improve plant growth, yield, and health and induce tolerance to abiotic and biotic stress. A tool for the use of competent endophytes in micropropagation under in vitro and ex vitro conditions is “biotization” of plantlets with useful bacterial and fungal inocula. Fungal inocula which are used commercially are e.g. arbuscular mycorrhizal fungi in form of spores and extraradical mycelium on different carrier materials like expanded clay, vermiculite, sand or peat. Furthermore representatives of the root fungal genus Trichoderma are applied as spores formulated in powder. Plantgrowth promoting rhizobacteria of the important genera Bacillus, Pseudomonas, Azospirillum and Azotobacter in form of lyophilised endospores/bacterial cells in powder or liquid formulation are also available on the market.

Composition and oxidation state of sulfur in atmospheric particulate matter

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A. F. Longo

2016-10-01

Full Text Available The chemical and physical speciation of atmospheric sulfur was investigated in ambient aerosol samples using a combination of sulfur near-edge x-ray fluorescence spectroscopy (S-NEXFS and X-ray fluorescence (XRF microscopy. These techniques were used to determine the composition and oxidation state of sulfur in common primary emission sources and ambient particulate matter collected from the greater Atlanta area. Ambient particulate matter samples contained two oxidation states: S0 and S+VI. Ninety-five percent of the individual aerosol particles (> 1 µm analyzed contain S0. Linear combination fitting revealed that S+VI in ambient aerosol was dominated by ammonium sulfate as well as metal sulfates. The finding of metal sulfates provides further evidence for acidic reactions that solubilize metals, such as iron, during atmospheric transport. Emission sources, including biomass burning, coal fly ash, gasoline, diesel, volcanic ash, and aerosolized Atlanta soil, and the commercially available bacterium Bacillus subtilis, contained only S+VI. A commercially available Azotobacter vinelandii sample contained approximately equal proportions of S0 and S+VI. S0 in individual aerosol particles most likely originates from primary emission sources, such as aerosolized bacteria or incomplete combustion.

Solution structures of lipoyl domains of the 2-oxo acid dehydrogenase complexes from Azotobacter vinelandii : implications for molecular recognition

NARCIS (Netherlands)

Berg, A.

1997-01-01

The 2-oxo acid dehydrogenase complexes are large multienzyme complexes that catalyse the irreversible oxidative decarboxylation of a specific 2-oxo acid to the corresponding acyl-CoA derivative. The pyruvate dehydrogenase complex (PDHC) converts the product of the glycolysis, pyruvate, to

Oxygen transfer rate during the production of alginate by Azotobacter vinelandii under oxygen-limited and non oxygen-limited conditions

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Peña Carlos F

2011-02-01

Full Text Available Abstract Background The oxygen transfer rate (OTR and dissolved oxygen tension (DOT play an important role in determining alginate production and its composition; however, no systematic study has been reported about the independent influence of the OTR and DOT. In this paper, we report a study about alginate production and the evolution of the molecular mass of the polymer produced by a wild-type A. vinelandii strain ATCC 9046, in terms of the maximum oxygen transfer rate (OTRmax in cultures where the dissolved oxygen tension (DOT was kept constant. Results The results revealed that in the two dissolved oxygen conditions evaluated, strictly controlled by gas blending at 0.5 and 5% DOT, an increase in the agitation rate (from 300 to 700 rpm caused a significant increase in the OTRmax (from 17 to 100 mmol L-1 h-1 for DOT of 5% and from 6 to 70 mmol L-1 h-1 for DOT of 0.5%. This increase in the OTRmax improved alginate production, as well as the specific alginate production rate (SAPR, reaching a maximal alginate concentration of 3.1 g L-1 and a SAPR of 0.031 g alg g biom-1 h-1 in the cultures at OTRmax of 100 mmol L-1 h-1. In contrast, the mean molecular mass (MMM of the alginate isolated from cultures developed under non-oxygen limited conditions increased by decreasing the OTRmax, reaching a maximal of 550 kDa at an OTRmax of 17 mmol L-1 h-1 . However, in the cultures developed under oxygen limitation (0.5% DOT, the MMM of the polymer was practically the same (around 200 kDa at 300 and 700 rpm, and this remained constant throughout the cultivation. Conclusions Overall, our results showed that under oxygen-limited and non oxygen-limited conditions, alginate production and its molecular mass are linked to the OTRmax, independently of the DOT of the culture.

Purification and cellular localization of wild type and mutated dihydrolipoyltransacetylases from Azotobacter vinelandii and Escherichia coli expressed in E. coli

NARCIS (Netherlands)

Schulze, Egbert; Westphal, Adrie H.; Veenhuis, Marten; Kok, Arie de

1992-01-01

Wild type dihydrolipoyltransacetylase(E2p)-components from the pyruvate dehydrogenase complex of A. vinelandii or E. coli, and mutants of A. vinelandii E2p with stepwise deletions of the lipoyl domains or the alanine- and proline-rich region between the binding and the catalytic domain have been

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

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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.

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

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Hingdri -

2013-03-01

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

Effect of Nitrogen and biological Fertilizers on Seed Yield and Fatty acid Composition of Sesame cultivars under Yazd conditions

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E Shakeri

2013-04-01

Full Text Available To investigate the effect of different levels of nitrogen fertilizer and biofertilizers Azotobacter sp. and Azosprillum sp. on seed yield, oil yield and its percent and fatty acid composition in three sesame (Sesamum indicum L. cultivars an experiment was conducted using splite plot factorial arrangement based on randomized complete block design with three replications at Agricultural and Natural Resources Reasearch Center of Yazd in 2009 cropping season. The treatments included : cultivars ( Darab-14, Jiroft and Yazdi assigned to main plots, nitrogen fertilizer (0, 25 and 50 kg ha-1 and biofertilizer (inoculation and no-inoculation as factorial were randomized in sub-plots. Oil percent was measured using the Soxhlet method and fatty acid composition was measured using GC method. Results showed the significant differenc among three varieties concerning seed yield, oil yield and four fatty acids (oleic, linoleic, palmetic and stearis acid. Seed yield, oil yield, Oleic, Linolenic and Arasshidic acid significantly increased with applying N fertilizer. Seed yield, oil yield and linolenic acid percent significantly increased with applying biofertilizer. Oleic acid percent had negative and significant correlation with Linoleic acid (r = -0.759** and stearic acid (r=-0.774** percent. Generally, results showed the importance of applying biofertilizers against chemical fertilizers to protect the environment from harmful chemical pollution.

Characterization of Diazotrophs Containing Mo-Independent Nitrogenases, Isolated from Diverse Natural Environments▿

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Betancourt, Doris A.; Loveless, Telisa M.; Brown, James W.; Bishop, Paul E.

2008-01-01

Molybdenum-independent nitrogenases were first described in the nitrogen-fixing bacterium Azotobacter vinelandii and have since been described in other diazotrophic bacteria. Previously, we reported the isolation of seven diazotrophs with Mo-independent nitrogenases from aquatic environments. In the present study, we extend these results to include diazotrophs isolated from wood chip mulch, soil, “paraffin dirt,” and sediments from mangrove swamps. Mo-deficient, N-free media under both aerobic and anaerobic conditions were used for the isolations. A total of 26 isolates were genetically and physiologically characterized. Their phylogenetic placement was determined using 16S rRNA gene sequence analysis. Most of the isolates are members of the gamma subdivision of the class Proteobacteria and appear to be specifically related to fluorescent pseudomonads and azotobacteria. Two other isolates, AN1 and LPF4, are closely related to Enterobacter spp. and Paenibacillus spp., respectively. PCR and/or Southern hybridization were used to detect the presence of nitrogenase genes in the isolates. PCR amplification of vnfG and anfG was used to detect the genetic potential for the expression of the vanadium-containing nitrogenase and the iron-only nitrogenase in the isolates. This study demonstrates that diazotrophs with Mo-independent nitrogenases can be readily isolated from diverse natural environments. PMID:18378646

Modelling of microbial polyhydroxyalkanoate surface binding protein PhaP for rational mutagenesis.

Science.gov (United States)

Zhao, Hongyu; Yao, Zhenyu; Chen, Xiangbin; Wang, Xinquan; Chen, Guo-Qiang

2017-11-01

Phasins are unusual amphiphilic proteins that bind to microbial polyhydroxyalkanoate (PHA) granules in nature and show great potential for various applications in biotechnology and medicine. Despite their remarkable diversity, only the crystal structure of PhaP A h from Aeromonas hydrophila has been solved to date. Based on the structure of PhaP A h , homology models of PhaP A z from Azotobacter sp. FA-8 and PhaP TD from Halomonas bluephagenesis TD were successfully established, allowing rational mutagenesis to be conducted to enhance the stability and surfactant properties of these proteins. PhaP A z mutants, including PhaP A z Q38L and PhaP A z Q78L, as well as PhaP TD mutants, including PhaP TD Q38M and PhaP TD Q72M, showed better emulsification properties and improved thermostability (6-10°C higher melting temperatures) compared with their wild-type homologues under the same conditions. Importantly, the established PhaP homology-modelling approach, based on the high-resolution structure of PhaP A h , can be generalized to facilitate the study of other PhaP members. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Effect of free and symbiotic nitrogen fixing bacterial co-inoculation on seed and seedling of soybean seeds produced under deficit water condition

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Hamed Hadi

2016-04-01

Full Text Available Effect of free and symbiotic nitrogen fixing bacteria on seed and seedling produced seeds under deficit irrigation was conducted in laboratory and field experiments in 2006. In laboratory of karaj’s Seed and Plant Research and Certificate Institute an experiment was conducted based on factorial in form of completely randomized design with four replications and in field’s of Islamic Azad University, Varamin Branch were split factorial in form of randomized completely block design with three replications. Treatments included water stress [Irrigation after 50 (Normal irrigation, 100 (Middle stress, 150 (Severe stress mm evaporation from pan class A], Cultivar [Manokin & Williams and SRF×T3 Line] and inoculation [Inoculation with Bradyrhizobium japonicum, Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum, No seed inoculation]. Results showed that drought stress decreased the uniformity and germination speed and seedling emergence. Bacteria increased leaf dry weight, stem dry weight, leaf area and seedling vigor index but had no effect on emergence. In irrigation levels inoculated treatments had higher seedling length, leaf, stem, seedling dry weight and seedling vigor. Severs stress seeds inoculated with Bradyrhizobium japonicum had higher root dry weight than control. Therefore in seeds which were produced under deficit irrigation conditions, bacteria increased seedlings vigor.

Role of conserved cysteine residues in Herbaspirillum seropedicae NifA activity.

Science.gov (United States)

Oliveira, Marco A S; Baura, Valter A; Aquino, Bruno; Huergo, Luciano F; Kadowaki, Marco A S; Chubatsu, Leda S; Souza, Emanuel M; Dixon, Ray; Pedrosa, Fábio O; Wassem, Roseli; Monteiro, Rose A

2009-01-01

Herbaspirillum seropedicae is an endophytic diazotrophic bacterium that associates with economically important crops. NifA protein, the transcriptional activator of nif genes in H. seropedicae, binds to nif promoters and, together with RNA polymerase-sigma(54) holoenzyme, catalyzes the formation of open complexes to allow transcription initiation. The activity of H. seropedicae NifA is controlled by ammonium and oxygen levels, but the mechanisms of such control are unknown. Oxygen sensitivity is attributed to a conserved motif of cysteine residues in NifA that spans the central AAA+ domain and the interdomain linker that connects the AAA+ domain to the C-terminal DNA binding domain. Here we mutagenized this conserved motif of cysteines and assayed the activity of mutant proteins in vivo. We also purified the mutant variants of NifA and tested their capacity to bind to the nifB promoter region. Chimeric proteins between H. seropedicae NifA, an oxygen-sensitive protein, and Azotobacter vinelandii NifA, an oxygen-tolerant protein, were constructed and showed that the oxygen response is conferred by the central AAA+ and C-terminal DNA binding domains of H. seropedicae NifA. We conclude that the conserved cysteine motif is essential for NifA activity, although single cysteine-to-serine mutants are still competent at binding DNA.

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

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Sarić-Krsmanović Marija

2017-01-01

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

The effect of dosages of microbial consortia formulation and synthetic fertilizer on the growth and yield of field-grown chili

Science.gov (United States)

Istifadah, N.; Sapta, D.; Krestini, H.; Natalie, B.; Suryatmana, P.; Nurbaity, A.; Hidersah, R.

2018-03-01

Chili (Capsicum annuum, L) is one of important horticultural crop in Indonesia. Formulation of microbial consortia containing Bacillus subtilis, Pseudomonas sp., Azotobacter chroococcum and Trichoderma harzianum has been developed. This study evaluated the effects of dosage of the microbial formulation combined with NPK fertilizer on growth and yield of chili plants in the field experiment. The experiment was arranged in completely randomized design of factorial, in which the first factor was dosage of formulation (0, 2.5, 5.0, 7.5, 10 g per plant) and the second factor was NPK fertilizer dosage (0, 25, 50 and 75% of the standard dosage). The treatments were replicated three times. For application, the formulation was mixed with chicken manure 1:10 (w/v). The results showed that application of microbial formulation solely improved the chili growth. There was interaction between dosages of the microbial formulation and NPK fertilizer in improving plant height, nitrogen availability and the chili yield, while there was no interaction between those dosages in improving the root length. Combination between microbial formulation at the dosage of 5.0-7.5 g per plant combined with NPK fertilizer with the dosage 50 or 75% of the standard dosage support relatively better growth and the chili yield.

Modification of "1"3"7Cs transfer to rape (Brassica napus L.) phytomass under the influence of soil microorganisms

International Nuclear Information System (INIS)

Pareniuk, O.; Shavanova, K.; Laceby, J.P.; Illienko, V.; Tytova, L.; Levchuk, S.; Gudkov, I.; Nanba, K.

2015-01-01

After nuclear accidents, such as those experienced in Chernobyl and Fukushima, microorganisms may help purify contaminated soils by changing the mobility of radionuclides and their availability for plants by altering the physical and chemical properties of the substrate. Here, using model experiments with quartz sand as a substrate we investigate the influence of microorganisms on "1"3"7Cs transfer from substrate to plants. The highest transition of "1"3"7Cs from substrate to plants (50% increase compared to the control) was observed after Brassica napus L. seeds were inoculated by Azotobacter chroococcum. The best results for reducing the accumulation of "1"3"7Cs radionuclides (30% less) were noted after the inoculation by Burkholderia sp.. Furthermore, Bacillus megaterium demonstrated an increased ability to accumulate "1"3"7Cs. This research improves our prediction of the behavior of radionuclides in soil and may contribute towards new, microbiological countermeasures for soil remediation following nuclear accidents. - Highlights: • Representatives of soil bacteria can alter "1"3"7Cs soil-to-plant transfer factor. • This ability does not depend on the localization of bacteria on the root surface. • Selection of bacteria to increase or decrease the "1"3"7Cs transfer factor is possible.

Phytoremediation of coal mine spoil dump through integrated biotechnological approach

Energy Technology Data Exchange (ETDEWEB)

Juwarkar, A.A.; Jambhulkar, H.P. [National Environmental Engineering Research Institute, Nagpur (India)

2008-07-15

Field experiment was conducted on mine spoil dump on an area of 10 ha, to restore the fertility and productivity of the coal mine spoil dump using integrated biotechnological approach. The approach involves use of effluent treatment plant sludge (ETP sludge), as an organic amendment, biofertilizers and mycorrihzal fungi along with suitable plant species. The results of the study indicated that amendment with effluent treatment plant sludge (ETP sludge), at 50 ton/ha improved the physico-chemical properties of coal mine spoil. Due to biofertilizer inoculation different microbial groups such as Rhizobium, Azotobacter and VAM spores, which were practically absent in mine spoil improved greatly. Inoculation of biofertilizer and application of ETP sludge helped in reducing the toxicity of heavy metals such as chromium, zinc, copper, iron, manganese lead, nickel and cadmium, which were significantly reduced to 41%, 43%, 37%, 37%, 34%, 39%, 37% and 40%, respectively, due to the increased organic matter content in the ETP sludge and its alkaline pH (8.10-8.28), at which the metals gets immobilized and translocation of metals is arrested. Thus, amendment and biofertilizer application provided better supportive material for anchorage and growth of the plant on coal mine spoil dump.

Structural and mutational characterization of the catalytic A-module of the mannuronan C-5-epimerase AlgE4 from Azotobacter vinelandii

NARCIS (Netherlands)

Rozeboom, Henriette J.; Bjerkan, Tonje M.; Kalk, Kor H.; Ertesvag, Helga; Holtan, Synnove; Aachmann, Finn L.; Valla, Svein; Dijkstra, Bauke W.; Ertesvåg, Helga; Holtan, Synnøve

2008-01-01

Alginate is a family of linear copolymers of (1 -> 4)-linked beta-D-mannuronic acid and its C-5 epimer alpha-L-guluronic acid. The polymer is first produced as polymannuronic acid and the guluronic acid residues are then introduced at the polymer level by mannuronan C-5-epimerases. The structure of

Role of microbial inoculation and industrial by-product phosphogypsum in growth and nutrient uptake of maize (Zea mays L.) grown in calcareous soil.

Science.gov (United States)

Al-Enazy, Abdul-Aziz R; Al-Oud, Saud S; Al-Barakah, Fahad N; Usman, Adel Ra

2017-08-01

Alkaline soils with high calcium carbonate and low organic matter are deficient in plant nutrient availability. Use of organic and bio-fertilizers has been suggested to improve their properties. Therefore, a greenhouse experiment was conducted to evaluate the integrative role of phosphogypsum (PG; added at 0.0, 10, 30, and 50 g PG kg -1 ), cow manure (CM; added at 50 g kg -1 ) and mixed microbial inoculation (Incl.; Azotobacter chroococcum, and phosphate-solubilizing bacteria Bacillus megaterium var. phosphaticum and Pseudomonas fluorescens) on growth and nutrients (N, P, K, Fe, Mn, Zn and Cu) uptake of maize (Zea mays L.) in calcareous soil. Treatment effects on soil chemical and biological properties and the Cd and Pb availability to maize plants were also investigated. Applying PG decreased soil pH. The soil available P increased when soil was inoculated and/or treated with CM, especially with PG. The total microbial count and dehydrogenase activity were enhanced with PG+CM+Incl. Inoculated soils treated with PG showed significant increases in NPK uptake and maize plant growth. However, the most investigated treatments showed significant decreases in shoot micronutrients. Cd and Pb were not detected in maize shoots. Applying PG with microbial inoculation improved macronutrient uptake and plant growth. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Fatty acids in an estuarine mangrove ecosystem

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Nabeel M Alikunhi

2010-06-01

Full Text Available Los ácidos grasos se han utilizado con éxito para estudiar la transferencia de materia orgánica en las redes alimentarias costeras y estuarinas. Para delinear las interacciones tróficas en las redes, se analizaron perfiles de ácidos grasos en las especies de microbios (Azotobacter vinelandii y Lactobacillus xylosus, camarones (Metapenaeus monoceros y Macrobrachium rosenbergii y peces (Mugil cephalus, que están asociadas con la descomposición de las hojas de dos especies de mangle, Rhizophora apiculata y Avicennia marina. Los ácidos grasos, con excepción de los de cadena larga, exhiben cambios durante la descomposición de las hojas de mangle, con una reducción de los ácidos grasos saturados y un aumento de los monoinsaturados. Los ácidos grasos ramificados están ausentes en las hojas de mangle sin descomponer, pero presentes de manera significativa en las hojas descompuestas, en camarones y peces, representando una fuente importante para ellos. Esto revela que los microbios son productores dominantes que contribuyen significativamente con los peces y camarones en el ecosistema de manglar. Este trabajo demuestra que los marcadores biológicos de los ácidos grasos son una herramienta eficaz para la identificación de las interacciones tróficas entre los productores dominantes y consumidores en este manglar.

History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience.

Science.gov (United States)

Baldani, José I; Baldani, Vera L D

2005-09-01

This review covers the history on Biological Nitrogen Fixation (BNF) in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of which was coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali), associative (Azospirillum lipoferum, A. brasilense, A. amazonense) and the endophytic (Herbaspirillum seropedicae, H. rubrisubalbicans, Gluconacetobacter diazotrophicus, Burkholderia brasilensis and B. tropica). The role of these diazotrophs in association with grasses, mainly with cereal plants, has been studied and a lot of progress has been achieved in the ecological, physiological, biochemical, and genetic aspects. The mechanisms of colonization and infection of the plant tissues are better understood, and the BNF contribution to the soil/plant system has been determined. Inoculation studies with diazotrophs showed that endophytic bacteria have a much higher BNF contribution potential than associative diazotrophs. In addition, it was found that the plant genotype influences the plant/bacteria association. Recent data suggest that more studies should be conducted on the endophytic association to strengthen the BNF potential. The ongoing genome sequencing programs: RIOGENE (Gluconacetobacter diazotrophicus) and GENOPAR (Herbaspirillum seropedicae) reflect the commitment to the BNF study in Brazil and should allow the country to continue in the forefront of research related to the BNF process in Graminaceous plants.

Efecto del uso del suelo sobre rizobacterias fosfatosolubizadoras y diazotroficas en el distrito de riego del río zulia,norte de santander (colombia

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Ronal Fernando-Cañon

2009-07-01

Full Text Available It was quantified the population of diazotrophic and phosphate solubilizer bacteria with the aim of determine the effect of the use of soils during different periods of intervention with culture of rice in three agro-ecological zones of the District of Irrigation of the Zulia river. The results showed that the management of the culture of rice in the different studied zones significantly influenced the population of microorganisms in all the studied culture media, excepting the semi-solid culture media JMV. The populations of the genera Azospirillum spp., Azotobacter spp., Beijerinckia spp., were influenced by the fertility of the soils in the zones of Buena Esperanza and Restauración compared with Limoncito, where the quantities of organic matter and nutritional escential elements were lower. It were obtained 28 isolations of entophytic, associative, free-living diazotrophic and phosphate solubilizer rhizobacteria according with their macroscopic characteristics in the culture media Batata, JMV, Ashby and nutritive, from the analysis of the population in the zones of Buena Esperanza, Restauración and Limoncito. These isolations were purified and preserved in sterilized saline solution (0.85% NaCl at 4°C in the Laboratory of Microbiology of the Colombian Agricultural Institute, ICA, with the purpose to be used in subsequent studies about their potential as biofertilizers in rice cultured soils of the department.

Aislamiento e identificación de microorganismos con potencial biofertilizante de suelos arroceros del distrito de riego del rio zulia, norte de santander

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Marilyn Tatiana Santos-Torres

2006-07-01

Full Text Available It was evaluated the microbial population of soils cultivated with rice at some zones of the district of irrigation of Zulia River, Norte de Santander state, Colombia, and no cultivated soil with rice. It was found that the seeded soil with rice were significantly low in fungi, bacteria and actinomycete populations compa red with no seeded with rice. This situation was due to possibly excessive use of agricultural machine and excessive application of pesticides and continuous rice monoculture. Therefore, with use the biofertilizer enriched with microorganism isolated from zone with similar agroecological conditions, will improve the microorganism adaptation of the rizosphere and will promote a reestablishment of the biological balance of soils and therefore to increase biotic activity improving the quality and productivity of the cultures. A total of 43 bacteria and 4 fungi were isolated in different soils of the studied zone, and were identified 25 microorganisms. According the isolation methodology, the bacteria were separate in two groups: diazotrophic like the species of the genera Azotobacter sp., Azospirillum sp. and Beijerinckia sp. and the phosphate solubilizate inorganic like Bacillus megaterium, B. cereus, Pseudomonas putida and P. aeruginosa. For the fungi identification were evaluate the micro and macroscopic characteristics in the culture medium Czapeck, following the fungi keys of Samson Hoekstra and Oorsehot (1981, which allowed recognize species like Trichoderma sp., Aspergillus niger, Penicillium purpurogenum, P. pinopilum.

Kinetics of Nif gene expression in a nitrogen-fixing bacterium.

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Poza-Carrión, César; Jiménez-Vicente, Emilio; Navarro-Rodríguez, Mónica; Echavarri-Erasun, Carlos; Rubio, Luis M

2014-02-01

Nitrogen fixation is a tightly regulated trait. Switching from N2 fixation-repressing conditions to the N2-fixing state is carefully controlled in diazotrophic bacteria mainly because of the high energy demand that it imposes. By using quantitative real-time PCR and quantitative immunoblotting, we show here how nitrogen fixation (nif) gene expression develops in Azotobacter vinelandii upon derepression. Transient expression of the transcriptional activator-encoding gene, nifA, was followed by subsequent, longer-duration waves of expression of the nitrogenase biosynthetic and structural genes. Importantly, expression timing, expression levels, and NifA dependence varied greatly among the nif operons. Moreover, the exact concentrations of Nif proteins and their changes over time were determined for the first time. Nif protein concentrations were exquisitely balanced, with FeMo cofactor biosynthetic proteins accumulating at levels 50- to 100-fold lower than those of the structural proteins. Mutants lacking nitrogenase structural genes or impaired in FeMo cofactor biosynthesis showed overenhanced responses to derepression that were proportional to the degree of nitrogenase activity impairment, consistent with the existence of at least two negative-feedback regulatory mechanisms. The first such mechanism responded to the levels of fixed nitrogen, whereas the second mechanism appeared to respond to the levels of the mature NifDK component. Altogether, these findings provide a framework to engineer N2 fixation in nondiazotrophs.

Interactions between nitrogen fixation and osmoregulation in the methanogenic archaeon Methanosarcina barkeri 227

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Brabban, A.D.; Orcutt, E.N.; Zinder, S.H. [Cornell Univ., Ithaca, NY (United States). Section of Microbiology

1999-03-01

The nitrogenase enzyme complex of Methanosarcina barkeri 227 was found to be more sensitive to NaCl than previously studied molybdenum nitrogenases are, with total inhibition of activity occurring at 190 mM NaCl, compared with >600 mM NaCl for Azotobacter vinelandii and Clostridium pasteurianum nitrogenases. Na{sup +} and K{sup +} had equivalent effects, whereas Mg{sup 2+} was more inhibitory than either monovalent cation, even on a per-charge basis. The anion Cl{sup {minus}} was more inhibitory than acetate was. Because M. barkeri 227 is a facultative halophile, the authors examined the effects of external salt on growth and diazotrophy and found that inhibition of growth was not greater with N{sub 2} than with NH{sub 4}{sup +}. Cells grown with N{sub 2} and cells grown with NH{sub 4}{sup +} produced equal concentrations of {alpha}-glutamate at low salt concentrations and equal concentrations of N{sup {var_epsilon}}-acetyl-{beta}-lysine at NaCl concentrations greater than 500 mM. Despite the high energetic cost of fixing nitrogen for these osmolytes, the authors obtained no evidence that there is a shift towards nonnitrogenous osmolytes during diazotrophic growth. In vitro nitrogenase enzyme assays showed that at a low concentration potassium glutamate enhanced activity but at higher concentrations this compound inhibited activity; 50% inhibition occurred at a potassium glutamate concentration of approximately 400 mM.

Association with an ammonium-excreting bacterium allows diazotrophic culture of oil-rich eukaryotic microalgae.

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Ortiz-Marquez, Juan Cesar Federico; Do Nascimento, Mauro; Dublan, Maria de Los Angeles; Curatti, Leonardo

2012-04-01

Concerns regarding the depletion of the world's reserves of oil and global climate change have promoted an intensification of research and development toward the production of biofuels and other alternative sources of energy during the last years. There is currently much interest in developing the technology for third-generation biofuels from microalgal biomass mainly because of its potential for high yields and reduced land use changes in comparison with biofuels derived from plant feedstocks. Regardless of the nature of the feedstock, the use of fertilizers, especially nitrogen, entails a potential economic and environmental drawback for the sustainability of biofuel production. In this work, we have studied the possibility of nitrogen biofertilization by diazotrophic bacteria applied to cultured microalgae as a promising feedstock for next-generation biofuels. We have obtained an Azotobacter vinelandii mutant strain that accumulates several times more ammonium in culture medium than wild-type cells. The ammonium excreted by the mutant cells is bioavailable to promote the growth of nondiazotrophic microalgae. Moreover, this synthetic symbiosis was able to produce an oil-rich microalgal biomass using both carbon and nitrogen from the air. This work provides a proof of concept that artificial symbiosis may be considered an alternative strategy for the low-N-intensive cultivation of microalgae for the sustainable production of next-generation biofuels and other bioproducts.

The Effect Different Fertilizers, on Germination, Yield, of Vicia vilosa Roth

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R Kamaei

2015-09-01

Full Text Available In order to study the interaction of germination, yield of Vicia vilosa Roth to use of biological fertilizer, chemical, and manure, an experiment was conducted as a randomized complete block design with three replications at Research greenhouse, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013-2014 growing season. The experimental treatments was included three kinds of bio fertilizers and their integration with each other and vermicompost and chemical fertilizer as following : 1- mycorhhizaarbuscular species Glomus mosseae+vermicompost2- mycorhhiza+Nitrocsin (included bacteries Azospirillum sp. and Azotobacter sp. 3- mycorhhiza arbuscular+ Rhizobium (Rhizobium sp. 4-mycorhhiza arbuscular + Chemical fertilizer NPK 5- mycorhhizaarbuscular (Glomus moseae 6-control. The results showed that, although the treatments has not significant effects on height of stem , it has significant effects on characteristics of root length colonization percent, number the root node, Root dry weight, soggy yield, yield dry and protein Percent. The results showed that the highest percent of root length colonization(76 percent, number the root node (20, Root dry weight (.94 g, soggy yield (1894.5 g m-2, yield dry (473.63 g m-2 and protein Percent (27.33 percent was gained in integrated mycorhhiza and nitrocsine treatment. On the basis of results, the integration of mycrhhoriza and biological rhizobium is suggested as the best fertilizer treatment for Vicia vilosa Roth.

RESISTANCE OF KARST CAVERNS NITROGEN-FIXING BACTERIA TO EXTREME FACTORS

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Tashyrev O. B.

2014-10-01

Full Text Available To determine the studied bacteria resistance quantitative parameters of extreme factors such as toxic metals (Cu2+, organic xenobiotics (p-nitrochlorobenzene and UV-irradiation were the aim of the research. Six strains of nitrogen-fixing bacteria isolated from clays of two caverns Mushkarova Yama (Podolia, Ukraine and Kuybyshevskaya (Western Caucasus, Abkhazia and Azotobacter vinelandii УКМ В-6017 as a reference strain have been tested. For this purpose the maximum permissible concentration of Cu2+ and p-nitrochlorobenzene in the concentration gradient and lethal doses of UV by the survival caverns have been determined. Maximum permissible concentrations for strains were as 10 ppm Cu2+, 70–120 ppm of p-nitrochlorobenzene. The maximum doses of UV-irradiation varied in the range of 55–85 J/m2 (LD99.99. It is shown that three classes of extreme factors resistance parameters of karst caverns strains are similar to the strain of terrestrial soil ecosystems. The most active studied strains reduce the concentration of p-nitrochlorobenzene in the medium in 13 times. The ability of nitrogen-fixing bacteria to degrade p-nitrochlorobenzene could be used in creation new environmental biotechnology for industrial wastewater treatment from nitrochloroaromatic xenobiotics. Isolated strains could be used as destructors for soils bioremediation in agrobiotechnologies and to optimize plants nitrogen nutrition in terrestrial ecosystems.

Chinese Milk Vetch Improves Plant Growth, Development and 15N Recovery in the Rice-Based Rotation System of South China.

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Xie, Zhijian; He, Yaqin; Tu, Shuxin; Xu, Changxu; Liu, Guangrong; Wang, Huimin; Cao, Weidong; Liu, Hui

2017-06-15

Chinese milk vetch (CMV) is vital for agriculture and environment in China. A pot experiment combined with 15 N labeling (including three treatments: control, no fertilizer N and CMV; 15 N-labeled urea alone, 15 NU; substituting partial 15 NU with CMV, 15 NU-M) was conducted to evaluate the impact of CMV on plant growth, development and 15 NU recovery in rice-based rotation system. The 15 NU-M mitigated oxidative damage by increasing antioxidant enzymes activities and chlorophyll content while decreased malondialdehyde content in rice root and shoot, increased the biomass, total N and 15 N uptake of plant shoots by 8%, 12% and 39% respectively, thus inducing a noticeable increase of annual 15 N recovery by 77% versus 15 NU alone. Remarkable increases in soil NH 4 + and populations of bacteria, actinomycetes and azotobacter were obtained in legume-rice rotation system while an adverse result was observed in soil NO 3 - content versus fallow-rice. CMV as green manure significantly increased the fungal population which was decreased with cultivating CMV as cover crop. Therefore, including legume cover crop in rice-based rotation system improves plant growth and development, annual N conservation and recovery probably by altering soil nitrogen forms plus ameliorating soil microbial communities and antioxidant system which alleviates oxidative damages in plants.

Fluorescence of Alexa fluor dye tracks protein folding.

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Simon Lindhoud

Full Text Available Fluorescence spectroscopy is an important tool for the characterization of protein folding. Often, a protein is labeled with appropriate fluorescent donor and acceptor probes and folding-induced changes in Förster Resonance Energy Transfer (FRET are monitored. However, conformational changes of the protein potentially affect fluorescence properties of both probes, thereby profoundly complicating interpretation of FRET data. In this study, we assess the effects protein folding has on fluorescence properties of Alexa Fluor 488 (A488, which is commonly used as FRET donor. Here, A488 is covalently attached to Cys69 of apoflavodoxin from Azotobacter vinelandii. Although coupling of A488 slightly destabilizes apoflavodoxin, the three-state folding of this protein, which involves a molten globule intermediate, is unaffected. Upon folding of apoflavodoxin, fluorescence emission intensity of A488 changes significantly. To illuminate the molecular sources of this alteration, we applied steady state and time-resolved fluorescence techniques. The results obtained show that tryptophans cause folding-induced changes in quenching of Alexa dye. Compared to unfolded protein, static quenching of A488 is increased in the molten globule. Upon populating the native state both static and dynamic quenching of A488 decrease considerably. We show that fluorescence quenching of Alexa Fluor dyes is a sensitive reporter of conformational changes during protein folding.

Metaproteomics analysis of the functional insights into microbial communities of combined hydrogen and methane production by anaerobic fermentation from reed straw.

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Xuan Jia

Full Text Available A metaproteomic approach was used to analyse the proteins expressed and provide functional evidence of key metabolic pathways in the combined production of hydrogen and methane by anaerobic fermentation (CHMP-AF for reed straw utilisation. The functions and structures of bacteria and archaea populations show significant succession in the CHMP-AF process. There are many kinds of bacterial functional proteins, mainly belonging to phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes, that are involved in carbohydrate metabolism, energy metabolism, lipid metabolism, and amino acid metabolism. Ferredoxin-NADP reductase, present in bacteria in genus Azotobacter, is an important enzyme for NADH/NAD+ equilibrium regulation in hydrogen production. The archaeal functional proteins are mainly involved in methane metabolism in energy metabolism, such as acetyl-CoA decarboxylase, and methyl-coenzyme M reductase, and the acetic acid pathway exhibited the highest proportion of the total. The archaea of genus Methanosarcina in phylum Euryarchaeota can produce methane under the effect of multi-functional proteins through acetic acid, CO2 reduction, and methyl nutrient pathways. The study demonstrates metaproteomics as a new way of uncovering community functional and metabolic activity. The combined information was used to identify the metabolic pathways and organisms crucial for lignocellulosic biomass degradation and biogas production. This also regulates the process from its protein levels and improves the efficiency of biogas production using reed straw biomass.

Metaproteomics analysis of the functional insights into microbial communities of combined hydrogen and methane production by anaerobic fermentation from reed straw

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Yang, Yang; Wang, Yong

2017-01-01

A metaproteomic approach was used to analyse the proteins expressed and provide functional evidence of key metabolic pathways in the combined production of hydrogen and methane by anaerobic fermentation (CHMP-AF) for reed straw utilisation. The functions and structures of bacteria and archaea populations show significant succession in the CHMP-AF process. There are many kinds of bacterial functional proteins, mainly belonging to phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes, that are involved in carbohydrate metabolism, energy metabolism, lipid metabolism, and amino acid metabolism. Ferredoxin-NADP reductase, present in bacteria in genus Azotobacter, is an important enzyme for NADH/NAD+ equilibrium regulation in hydrogen production. The archaeal functional proteins are mainly involved in methane metabolism in energy metabolism, such as acetyl-CoA decarboxylase, and methyl-coenzyme M reductase, and the acetic acid pathway exhibited the highest proportion of the total. The archaea of genus Methanosarcina in phylum Euryarchaeota can produce methane under the effect of multi-functional proteins through acetic acid, CO2 reduction, and methyl nutrient pathways. The study demonstrates metaproteomics as a new way of uncovering community functional and metabolic activity. The combined information was used to identify the metabolic pathways and organisms crucial for lignocellulosic biomass degradation and biogas production. This also regulates the process from its protein levels and improves the efficiency of biogas production using reed straw biomass. PMID:28817657

Evaluation of bacterial run and tumble motility parameters through trajectory analysis

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Liang, Xiaomeng; Lu, Nanxi; Chang, Lin-Ching; Nguyen, Thanh H.; Massoudieh, Arash

2018-04-01

In this paper, a method for extraction of the behavior parameters of bacterial migration based on the run and tumble conceptual model is described. The methodology is applied to the microscopic images representing the motile movement of flagellated Azotobacter vinelandii. The bacterial cells are considered to change direction during both runs and tumbles as is evident from the movement trajectories. An unsupervised cluster analysis was performed to fractionate each bacterial trajectory into run and tumble segments, and then the distribution of parameters for each mode were extracted by fitting mathematical distributions best representing the data. A Gaussian copula was used to model the autocorrelation in swimming velocity. For both run and tumble modes, Gamma distribution was found to fit the marginal velocity best, and Logistic distribution was found to represent better the deviation angle than other distributions considered. For the transition rate distribution, log-logistic distribution and log-normal distribution, respectively, was found to do a better job than the traditionally agreed exponential distribution. A model was then developed to mimic the motility behavior of bacteria at the presence of flow. The model was applied to evaluate its ability to describe observed patterns of bacterial deposition on surfaces in a micro-model experiment with an approach velocity of 200 μm/s. It was found that the model can qualitatively reproduce the attachment results of the micro-model setting.

Survival of microorganisms in smectite clays: Implications for Martian exobiology

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Moll, Deborah M.; Vestal, J. Robie

1992-08-01

Manned exploration of Mars may result in the contamination of that planet with terrestrial microbes, a situation requiring assessment of the survival potential of possible contaminating organisms. In this study, the survival of Bacillus subtilis, Azotobacter chroococcum, and the enteric bacteriophage MS2 was examined in clays representing terrestrial (Wyoming type montmorillonite) or Martian (Fe 3+-montmorillonite) soils exposed to terrestrial and Martian environmental conditions of temperature and atmospheric pressure and composition, but not to UV flux or oxidizing conditions. Survival of bacteria was determined by standard plate counts and biochemical and physiological measurements over 112 days. Extractable lipid phosphate was used to measure microbial biomass, and the rate of 14C-acetate incorporation into microbial lipids was used to determine physiological activity. MS2 survival was assayed by plaque counts. Both bacterial types survived terrestrial or Martian conditions in Wyoming montmorillonite better than Martian conditions in Fe 3+-montmorillonite. Decreased survival may have been caused by the lower pH of the Fe 3+-montmorillonite compared to Wyoming montmorillonite. MS2 survived simulated Mars conditions better than the terrestrial environment, likely due to stabilization of the virus caused by the cold and dry conditions of the simulated Martian environment. The survival of MS2 in the simulated Martian environment is the first published indication that viruses may be able to survive in Martian type soils. This work may have implications for planetary protection for future Mars missions.

Diversity and Functional Analysis of the FeMo-Cofactor Maturase NifB

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Simon Arragain

2017-11-01

Full Text Available One of the main hurdles to engineer nitrogenase in a non-diazotrophic host is achieving NifB activity. NifB is an extremely unstable and oxygen sensitive protein that catalyzes a low-potential SAM-radical dependent reaction. The product of NifB activity is called NifB-co, a complex [8Fe-9S-C] cluster that serves as obligate intermediate in the biosyntheses of the active-site cofactors of all known nitrogenases. Here we study the diversity and phylogeny of naturally occurring NifB proteins, their protein architecture and the functions of the distinct NifB domains in order to understand what defines a catalytically active NifB. Focus is on NifB from the thermophile Chlorobium tepidum (two-domain architecture, the hyperthermophile Methanocaldococcus infernus (single-domain architecture and the mesophile Klebsiella oxytoca (two-domain architecture, showing in silico characterization of their nitrogen fixation (nif gene clusters, conserved NifB motifs, and functionality. C. tepidum and M. infernus NifB were able to complement an Azotobacter vinelandii (ΔnifB mutant restoring the Nif+ phenotype and thus demonstrating their functionality in vivo. In addition, purified C. tepidum NifB exhibited activity in the in vitro NifB-dependent nitrogenase reconstitution assay. Intriguingly, changing the two-domain K. oxytoca NifB to single-domain by removal of the C-terminal NifX-like extension resulted in higher in vivo nitrogenase activity, demonstrating that this domain is not required for nitrogen fixation in mesophiles.

N2 fixer free-living bacteria in two soils of Cauca Valley

International Nuclear Information System (INIS)

Cardona M, Sigifredo; Sanchez de Prager, Marina

1998-01-01

Several soil samples were taken in two agricultural soils, located in Palmira and Ricaurte, Cauca Valley, with the aim of establishing the presence of free life N 2 fixer bacteria and to identify the predominant species. Such soils were chemical and physically characterized and were collected information about their farmer management. For each one of them were counted the N 2 a symbiotic fixers by the dilution method and culture in N free Ashby media. The main bacteria isolated in each soil were, purified and identified. The physical chemistry conditions in both soils favored the presence of such microorganisms because of the pH, closer to neutral and an adequate nutrient content in Ricaurte, the soils was an inceptisol, moderately deep and growing passion fruit Passiflora edulis sims, in which have had an intensive use of chemicals, similar to palmira's soil; there, the microbial population was 5.5 x 107 U.F.C. N 2 fixer bacteria/g of dry soil. In Palmira, it was a mollisol growing tomato Lycopersicon esculentum mill with a population of 5.1 x 107 U.F.C./g of dry soil; both figures indicated the abundance of such microbiological resource and the potential for being explored in sustainable agricultural systems. In Ricaurte it was isolated Azotobacter is a main strain (probably a. chroococcum, according IMI) and in Palmira, Stenotroghomonas maltophilia (IMI), well known as a growth promoter in wheat and sunflower; referred in some cases as lightly pathogen in humans

Effects of organic and biological fertilizers on fruit yield and essential oil of sweet fennel (Foeniculum vulgare var. dulce)

Energy Technology Data Exchange (ETDEWEB)

Moradi, R.; Rezvani Moghaddam, P.; Nasiri Mahallati, M.; Nezhadali, A.

2011-07-01

In order to evaluate the effects of different organic and biological fertilizers on quantity and quality of fennel essential oil, an experiment was conducted in a completely randomized block design with three replications. The experimental treatments included two organic (compost and vermicompost) and two biological (Pseudomonas putida and Azotobacter chroococcum) fertilizers, their all twin combinations (Ps. putida + A. chroococcum, Ps. putida + compost, Ps. putida + vermicompost, A. chroococcum + compost, A. chroococcum + vermicompost and compost + vermicompost) and control (non fertilized). There were significant differences between treatments in terms of seed essential oil percentage, essential oil yield; anethole, fenchone, limonene and straggle content in seed essential oil. Results showed that the highest and the lowest percentages of essential oil were obtained in control (2.9%) and A. chroococcum + vermicompost (2.2%) treatments, respectively. The highest essential oil yield (29.9 L ha{sup -}1) and anethole content of essential oil (69.7%) and the lowest contents of fenchone (6.14%), limonene (4.84%) and estragole (2.78%) in essential oil were obtained in compost + vermicompost treatment. It seems that compost + vermicompost treatment compared to other treatments supplied the highest equilibrium of nutrients and water in the root zone of sweet fennel which is led to increasing the anethole content, there upon, decreasing other compounds. Essential oil yield and percentage of anethole content in essential oil were significantly higher in all organic and biological treatments compared with control. (Author) 43 refs.

Interaction of GlnK with the GAF domain of Herbaspirillum seropedicae NifA mediates NH₄⁺-regulation.

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Oliveira, Marco A S; Aquino, Bruno; Bonatto, Ana Claudia; Huergo, Luciano F; Chubatsu, Leda S; Pedrosa, Fábio O; Souza, Emanuel M; Dixon, Ray; Monteiro, Rose A

2012-04-01

Nitrogen fixation in Herbaspirillum seropedicae is transcriptionally regulated by NifA, a σ(54) transcriptional activator with three structural domains: an N-terminal GAF domain, a catalytic AAA+ domain and a C-terminal DNA-binding domain. NifA is only active in H. seropedicae when cultures are grown in the absence of fixed nitrogen and at low oxygen tensions. There is evidence that the inactivation of NifA in response to fixed nitrogen is mediated by the regulatory GAF domain. However, the mechanism of NifA repression by the GAF domain, as well as the transduction of nitrogen status to NifA, is not understood. In order to study the regulation of NifA activity by fixed nitrogen independently of oxygen regulation, we constructed a chimeric protein containing the GAF domain of H. seropedicae NifA fused to the AAA+ and C-terminal domains of Azotobacter vinelandii NifA. This chimeric protein (NifAQ1) lacks the cysteine motif found in oxygen sensitive NifA proteins and is not oxygen responsive in vivo. Our results demonstrate that NifAQ1 responds to fixed nitrogen and requires GlnK protein for activity, a behavior similar to H. seropedicae NifA. In addition, protein footprinting analysis indicates that this response probably involves a protein-protein contact between the GAF domain and the GlnK protein. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Transition-state analysis of a Vmax mutant of AMP nucleosidase by the application of heavy-atom kinetic isotope effects

International Nuclear Information System (INIS)

Parkin, D.W.; Mentch, F.; Banks, G.A.; Horenstein, B.A.; Schramm, V.L.

1991-01-01

The transition state of the V max mutant of AMP nucleosidase from Azotobacter vinelandii has been characterized by heavy-atom kinetic isotope effects in the presence and absence of MgATP, the allosteric activator. The enzyme catalyzes hydrolysis of the N-glycosidic bond of AMP at approximately 2% of the rate of the normal enzyme with only minor changes in the K m for substrate, the activation constant for MgATP, and the K i for formycin 5'-phosphate, a tight-binding competitive inhibitor. Isotope effects were measured as a function of the allosteric activator concentration that increases the turnover number of the enzyme from 0.006 s -1 . The kinetic isotope effects were measured with the substrates [1'- 3 H]AMP, [2'- 2 H]AMP, [9- 15 N]AMP, and [1',9- 14 C, 15 N]AMP. All substrates gave significant kinetic isotope effects in a pattern that establishes that the reaction expresses intrinsic kinetic isotope effects in the presence or absence of MgATP. Transition-state analysis using bond-energy and bond-order vibrational analysis indicated that the transition state for the mutant enzyme has a similar position in the reaction coordinate compared to that for the normal enzyme. The mutant enzyme is less effective in stabilizing the carbocation-like intermediate and in the ability to protonate N7 of adenine to create a better leaving group. This altered transition-state structure was confirmed by an altered substrate specificity for the mutant protein

Respuesta del garbanzo (Cicer arietinum L. a la inoculación con Azotobacter vineladii y Burkholderia cepacia a dosis reducida de fertilizante nitrogenado

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Juan Manuel Sánchez-Yáñez

2014-01-01

Full Text Available ResumenEl cultivo de garbanzo “Cicer arietinumL.” demanda fertilizante nitrogenado (FN, que aplicado en excesoprovoca pérdida de fertilidad del suelo y contaminación ambiental. Una alternativa para este problema es lareducción y optimización de la dosis de FN, con inoculantes a base de bacteriaspromotoras de crecimientovegetal (BPCV.Así, el objetivo de este trabajo fue analizar la respuesta del garbanzo a la inoculación conAzotobactervinelandiiyBurkholderiacepaciaa la dosis 50% del FN. Para ello se utilizó un diseñoexperimental de bloques al azar. Con nitrato de amonio (NO3NH4 como FN a las dosis 100% (10g/L y 50 %(5g/L para el garbanzo inoculado con las BPCV; con las variables/respuesta en su semilla: por ciento (% degerminación; luego su fenotípia y biomasa aérea y radical, los datos experimentales se analizaron por ANOVAy Tukey. Los resultados indicaron una respuesta positiva de la semilla de garbanzo a la doble inoculación conambas BPCV, al igual que aplántula y floración, donde el garbanzo alcanzo un peso seco total (PST de 0,82g, valor estadísticamente diferente y significativo, comparado con los 0,71g de PST del garbanzo sin inocularcon el FN al 100% o control relativo (CR. Lo anterior sugiereuna respuesta positiva del garbanzo queoptimizó la dosis 50% del FN, por una acción sinérgica de los dos géneros de BPCV en sus raíces, lo quepodría evitar en parte la perdida de fertilidad del suelo y la contaminación ambiental, por la aplicación enexceso del FN.

Produção de alginato por microrganismos Alginate production by microorganisms

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José Miguel Müller

2011-01-01

Full Text Available O alginato é um copolímero linear constituído de unidades de ácidos α-L-gulurônicos e β-D-manurônicos e é extensamente utilizado devido as suas propriedades espessantes, estabilizantes e gelificantes. Estas características fazem com que este biopolímero encontre aplicações na indústria de alimentos, na indústria têxtil e de papel, em cosméticos e na área farmacêutica e médica. Atualmente para este conjunto de aplicações sua principal fonte são algas marrons, entretanto, o alginato pode ser obtido a partir de biossíntese, utilizando-se microrganismos do gênero Pseudomonas e Azotobacter. A produção bacteriana de alginato apresenta-se como uma alternativa interessante e sua produção por microrganismos, além de possibilitar a produção de biopolímeros de alta qualidade com características específicas e pré-determinadas, irá diminuir o impacto ambiental nas regiões em que as algas marinhas das quais é extraído são coletadas. Nos últimos anos, vários estudos relacionados à produção de alginato por microrganismos foram realizados com o objetivo de avaliar sua produção e rota metabólica de biossíntese, para caracterizar o material produzido e para determinar as potencialidades de aplicação deste novo material. O rápido desenvolvimento de aplicações do alginato na área médica e farmacêutica, bem como a descoberta de propriedades imunológicas únicas deste material tem aumentado o interesse no desenvolvimento de processos para produzi-lo. Neste artigo são abordados aspectos relacionados à produção e as características do alginato bacteriano e também reportadas às potencialidades e aplicações inovadoras nas quais este material vem sendo utilizado.Alginate is a linear copolymer consisting of units of α-L-guluronic and β-D-mannuronic acid which is widely used due to its thickening, stabilizing and gelling properties. These characteristics mean that it has many applications in the food

History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience

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José I. Baldani

2005-09-01

Full Text Available This review covers the history on Biological Nitrogen Fixation (BNF in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of whichwas coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali, associative (Azospirillum lipoferum, A. brasilense, A. amazonense and the endophytic (Herbaspirillum seropedicae, H. rubrisubalbicans, Gluconacetobacter diazotrophicus, Burkholderia brasilensis and B. tropica. The role of these diazotrophs in association with grasses, mainly with cereal plants, has been studied and a lot of progress has been achieved in the ecological, physiological, biochemical, and genetic aspects. The mechanisms of colonization and infection of the plant tissues are better understood, and the BNF contribution to the soil/plant system has been determined. Inoculation studies with diazotrophs showed that endophytic bacteria have a much higher BNF contribution potential than associative diazotrophs. In addition, it was found that the plant genotype influences the plant/bacteria association. Recent data suggest that more studies should be conducted on the endophytic association to strengthen the BNF potential. The ongoing genome sequencing programs: RIOGENE (Gluconacetobacter diazotrophicus and GENOPAR (Herbaspirillum seropedicae reflect the commitment to the BNF study in Brazil and should allow the country to continue in the forefront of research related to the BNF process in Graminaceous plants.A presente revisão aborda a história da Fixação Biológica de Nitrogênio (FBN em Gramíneas no Brasil, procurando mostrar a evolução da pesquisa na área iniciada a mais de 40 anos sob a liderança da pesquisadora Johanna Döbereiner. Um aspecto marcante deste período foi a descoberta de diversas bactérias fixadoras de nitrogênio atmosf

Effect of malachite green toxicity on non target soil organisms.

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Gopinathan, R; Kanhere, J; Banerjee, J

2015-02-01

Although malachite green (MG), is banned in Europe and US for its carcinogenic and teratogenic effect, the dye being cheap, is persistently used in various countries for fish farming, silk, dye, leather and textile industries. Current research, however, fails to elucidate adequate knowledge concerning the effects of MG in our ecosystem. In the present investigation, for the first time, an attempt has been made to study the effects of MG on soil biota by testing Bacillus subtilis, Azotobacter chroococcum, Saccharomyces cerevisiae, Penicillium roqueforti, Eisenia fetida and seeds of three crop plants of different families. Various tests were conducted for determining cytotoxicity, genotoxicity, acute toxicity, morphological and germination effect. Our data confirmed MG toxicity on fungi and bacteria (gram positive and gram negative organisms) showing elevated level of ROS. Genotoxicity caused in the microorganisms was detected by DNA polymorphism and fragmentation. Also, scanning electron microscopy data suggests that the inhibitory effect of MG to these beneficial microbes in the ecosystem might be due to pore formation in the cell and its eventual disruption. Filter paper and artificial soil test conducted on earthworms demonstrated a LC 50 of 2.6 mg cm(-2) and 1.45 mg kg(-1) respectively with severe morphological damage. However, seed germination of Mung bean, Wheat and Mustard was found to be unaffected in presence of MG up to 100 mL(-1) concentration. Thus, understanding MG toxicity in non target soil organisms and emphasis on its toxicological effects would potentially explicate its role as an environmental contaminant. Copyright © 2014 Elsevier Ltd. All rights reserved.

Importance of molybdenum in the nitrogen metabolism of microorganisms and higher plants

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Mulder, E G

1948-01-01

The effect of molybdenum on the growth of microorganisms and higher plants and on some well-defined biochemical reactions was investigated. Results indicate that Aspergillus niger requires small amounts of molybdenum when growing in a culture solution supplied with nitrate nitrogen. With ammonium sulfate as a source of nitrogen, the response of the fungus to molybdenum was much smaller. It was shown that this different response of Aspergillus to molybdenum was not brought about by a difference in purity of both nitrogen compounds used, nor by a difference in absorption of the molybdenum impurity, but by a considerably higher requirement of molybdenum in a medium with nitrate nitrogen. The growth-rate curve and the increasing sporulation of Aspergillus niger with increasing amounts of molybdenum were used in estimating very small amounts of this element in various materials. In culture solution experiments with tomato, barley and oat plants the effect of traces of molybdenum on the growth of these plants was investigated. In good agreement with the results of the experiments with Aspergillus and denitrifying bacteria it could be shown that in the green plant as in these microorganisms molybdenum is acting as a catalyst in nitrate reduction. In experiments with Azotobacter chroococcum and leguminous plants the effect of molybdenum on the fixation of gaseous N/sub 2/ was studied. In culture solutions with pea plants the effect of molybdenum on the nitrogen fixation of the nodules was investigated. In the absence of molybdenum as well as in a complete nutrient medium many nodules were formed. 30 references, 6 figures, 16 tables.

Enhancement of Chlorella vulgaris growth and bioremediation ability of aquarium wastewater using diazotrophs.

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Ali, Sayeda Mohammed; Nasr, Hoda Shafeek; Abbas, Wafaa Tawfik

2012-08-15

Treatment of aquarium wastewater represents an important process to clean and recycle wastewater to be safely returned to the environment, used for cultivation or to minimize the multiple renewal of water. Chlorella vulgaris was an important freshwater microalgae which used in wastewater treatment, and increasing its potential of treatment can be achieved with existence of N2-fixing bacteria. Co-culturing of Chlorella vulgaris with the diazotrophs, Azospirillum brasilense or Azotobacter chroococcum in three different media; aquarium wastewater (AWW), sterile enriched natural aquarium wastewater (GPM) and synthetic wastewater media (SWW) were studied. Biomass yield of the microalgae was estimated by determination of chlorophylls (a and b), total carotenoid and the dry weight of C. vulgaris. Also determination of ammonia, nitrite, phosphate and nitrate in the culture were done. The presence of diazotrophs significantly increased the biomass of C. vulgaris by increasing its microalgae pigments (chlorophylls a and b, and total carotenoids). The highest pigments percentage was reported due to addition of A. brasilense to C. vulgaris (18.3-133.5%) compared to A. chroococcum (23.9-56.9%). As well as increased dry weight from 12 to 50%. There was also improved removal of nitrate, nitrite, ammonia and phosphate; where, the highest removal percentage was reported due to addition of A. chroococcum to C. vulgaris (0.0-52%) compared to A. brasilense (0.6-16.4%). A. brasilense and A. chroococcum can support C. vulgaris biomass production and bioremediation activity in the aquarium to minimize the periodical water renewal.

Agronomic efficiency INIAP-17 rice with levels of chemical and biological fertilization in Ecuadorian Coast

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Eduardo Neptali Colina Navarrete

2017-05-01

Full Text Available The investigation was carried out in the experimental farm of the College of Agricultural Sciences of the Technical University of Babahoyo, canton Babahoyo. Ten treatments were evaluated with three repetitions. The objective was to analyze the influence of four organic bioestimulantes on the efficiency of the conventional chemical fertilization in rice (Oryza sativa, to measure the effect on the agronomic behavior of the cultivation. The variety of rice INIAP-17 was sowed in parcels of 20 m2. The treatments were distributed at random in a design of complete blocks. For the evaluation of stockings the test was used from Tukey to significancia 5%. At the end of the cycle of the cultivation was evaluated: height of plants, sprout number for m2, grains for panicles, length and number of panicles m2, days to flowering, days to crop, number of grains for panicles, weight 1000 grains and yield for hectare. The results determined that the application of a program of high fertilization level (140-60-90-30 kg/ha, of N-P-K-S + Azospirillum 3 L/ha, the grain yield increased with increments of 23,44% with relationship to the witness. In the same way applications of Bacilllus and Azotobacter more levels means (120-40-60-20 and first floor (100-30-40-10 of application of N-P-K-S, they don't impact in days to the flowering, tipping, weight of 1000 grains, number of grains for panicles and relationship grain/straw.

[Effects of legume-oat intercropping on abundance and community structure of soil N2-fixing bacteria].

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Yang, Ya Dong; Feng, Xiao Min; Hu, Yue Gao; Ren, Chang Zhong; Zeng, Zhao Hai

2017-03-18

In this study, real-time PCR and high-throughput sequencing approaches were employed to investigate the abundance and community structure of N 2 -fixing bacteria in a field experiment with three planting patterns (Oat monoculture, O; Soybean-oat intercropping, OSO; Mung bean-oat intercropping, OMO). The results showed that soil chemical properties varied significantly in different soil samples (P＜0.05). The abundance of nifH gene varied from 1.75×10 10 to 7.37×10 10 copies·g -1 dry soil in all soil samples. The copy numbers of nifH gene in OSO and OMO were 2.18, 2.64, and 1.92, 2.57 times as much as that in O at jointing and mature stages, with a significant decline from jointing to mature stage for all treatments (P＜0.05). Rarefaction curve and cove-rage results proved the nifH gene sequencing results were reliable, and the diversity index showed that the N 2 -fixing bacteria diversity of OSO was much higher than that of O. Azohydromonas, Azotobacter, Bradyrhizobium, Skermanella and other groups that could not be classified are the dominant genera, with significant differences in proportion of these dominant groups observed among all soil samples (P＜0.05). Venn and PCA analysis indicated that there were greater differences of nifH gene communities between jointing and mature stages; however, the OSO and OMO had similar communities in both stages. All these results confirmed that legume-oat intercropping significantly increased the abundance and changed the community composition of N 2 -fixing bacteria in oat soils.

Bacterial nitrogen fixation in sand bioreactors treating winery wastewater with a high carbon to nitrogen ratio.

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Welz, Pamela J; Ramond, Jean-Baptiste; Braun, Lorenz; Vikram, Surendra; Le Roes-Hill, Marilize

2018-02-01

Heterotrophic bacteria proliferate in organic-rich environments and systems containing sufficient essential nutrients. Nitrogen, phosphorus and potassium are the nutrients required in the highest concentrations. The ratio of carbon to nitrogen is an important consideration for wastewater bioremediation because insufficient nitrogen may result in decreased treatment efficiency. It has been shown that during the treatment of effluent from the pulp and paper industry, bacterial nitrogen fixation can supplement the nitrogen requirements of suspended growth systems. This study was conducted using physicochemical analyses and culture-dependent and -independent techniques to ascertain whether nitrogen-fixing bacteria were selected in biological sand filters used to treat synthetic winery wastewater with a high carbon to nitrogen ratio (193:1). The systems performed well, with the influent COD of 1351 mg/L being reduced by 84-89%. It was shown that the nitrogen fixing bacterial population was influenced by the presence of synthetic winery effluent in the surface layers of the biological sand filters, but not in the deeper layers. It was hypothesised that this was due to the greater availability of atmospheric nitrogen at the surface. The numbers of culture-able nitrogen-fixing bacteria, including presumptive Azotobacter spp. exhibited 1-2 log increases at the surface. The results of this study confirm that nitrogen fixation is an important mechanism to be considered during treatment of high carbon to nitrogen wastewater. If biological treatment systems can be operated to stimulate this phenomenon, it may obviate the need for nitrogen addition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial consortium role in processing liquid waste of vegetables in Keputran Market Surabaya as organic liquid fertilizer ferti-plus

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Rizqi, Fauziah; Supriyanto, Agus; Lestari, Intan; Lita Indri D., L.; Elmi Irmayanti, A.; Rahmaniyah, Fadilatur

2016-03-01

Many activities in this market is directly proportional to increase production of vegetables waste, especially surabaya. Therefore, in this study aims to utilize liquid waste of vegetables into liquid organic fertilizer by mixing microbial consorsium. The microbial consorsium consist of Azotobacter chrococcum, Azospirillum brasilense, Rhizobium leguminosarum, Bacillus subtilis, Bacillus megaterium, Pseudomonas putida, and Pseudomonas fluorescens. Ttreatment of microbial concentrations (5%, 10%, 15%) and the length of the incubation period (7 days, 14 days, 21 days) used in this research. The parameters used are: C/N ratio, levels of CNP, and BOD value. This study uses a standard organic fertilizer value according SNI19-7030-2004, The results show the value of C/N ratio comply with the ISO standards. C levels showed an increase during the incubation period but not compare with standards. N levels that compare with standards are microbial treatment in all group concentration except control group with an incubation period of 21 days is > 7. P levels compare with the existing standards in the group of microbe concentration of 10% and 15% during the incubation period. The value of the initial BOD liquid waste of vegetable is 790.25 mg / L, this value indicates that the waste should not go into the water body. Accordingly, the results of this study can not be used as a liquid organic fertilizer, but potentially if it is used as a natural career or build natural soil. The Building natural soil is defined as the natural ingredients that can be used to improve soil properties.

Structural characterization of CO-inhibited Mo-nitrogenase by combined application of nuclear resonance vibrational spectroscopy, extended X-ray absorption fine structure, and density functional theory: new insights into the effects of CO binding and the role of the interstitial atom.

Science.gov (United States)

Scott, Aubrey D; Pelmenschikov, Vladimir; Guo, Yisong; Yan, Lifen; Wang, Hongxin; George, Simon J; Dapper, Christie H; Newton, William E; Yoda, Yoshitaka; Tanaka, Yoshihito; Cramer, Stephen P

2014-11-12

The properties of CO-inhibited Azotobacter vinelandii (Av) Mo-nitrogenase (N2ase) have been examined by the combined application of nuclear resonance vibrational spectroscopy (NRVS), extended X-ray absorption fine structure (EXAFS), and density functional theory (DFT). Dramatic changes in the NRVS are seen under high-CO conditions, especially in a 188 cm(-1) mode associated with symmetric breathing of the central cage of the FeMo-cofactor. Similar changes are reproduced with the α-H195Q N2ase variant. In the frequency region above 450 cm(-1), additional features are seen that are assigned to Fe-CO bending and stretching modes (confirmed by (13)CO isotope shifts). The EXAFS for wild-type N2ase shows evidence for a significant cluster distortion under high-CO conditions, most dramatically in the splitting of the interaction between Mo and the shell of Fe atoms originally at 5.08 Å in the resting enzyme. A DFT model with both a terminal -CO and a partially reduced -CHO ligand bound to adjacent Fe sites is consistent with both earlier FT-IR experiments, and the present EXAFS and NRVS observations for the wild-type enzyme. Another DFT model with two terminal CO ligands on the adjacent Fe atoms yields Fe-CO bands consistent with the α-H195Q variant NRVS. The calculations also shed light on the vibrational "shake" modes of the interstitial atom inside the central cage, and their interaction with the Fe-CO modes. Implications for the CO and N2 reactivity of N2ase are discussed.

Distribution of bacteria and fungi in the earthworm Libyodrillus violaceous (Annelida: Oligochaeta, a native earthworm from Nigeria

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A. B Idowu

2006-03-01

Full Text Available Earthworms are soil invertebrates that play a key role in recycling organic matter in soils.In Nigeria, earthworms include Libyodrillus violaceous. Aerobic and anaerobic bacterial counts, as well as fungal counts of viable microorganisms in soils and gut sections, were made on twenty L. violaceous collected from different sites on the campus of the University of Agriculture, Abeokuta, Nigeria. The samples were collected between April and November, 2002. Numbers of microorganisms were higher in castings and gut sections than in uningested soil samples. The guts and their contents also had higher moisture and total nitrogen contents than the uningested soils. Bacteria and fungi isolated from the samples were identified by standard microbiological procedures on the bases of their morphological and biochemical characteristics. Isolated bacteria were identified as Staphylococcus, Bacillus spp., Pseudomonas aeruginosa, Streptococcus mutans, Clostridium, Spirocheata spp., Azotobacter spp., Micrococcus lylae, Acinetobacter spp., Halobacterium for bacteria. Yeast isolates were identified as Candida spp., Zygosaccharomyces spp., Pichia spp., and Saccharomyces spp while molds were identified as, Aspergillus spp., Pytium spp., Penicillium spp., Fusarium spp and Rhizopus spp. Of the five locations examined, the refuse dump area had the highest numbers of both aerobic and anaerobic organisms, followed by the arboretum while the cultivated land area recorded the lowest counts. The higher numbers of microorganisms observed in the gut sections and casts of the earthworms examined in this work reinforce the general concept that the gut and casts of earthworms show higher microbial diversity and activity than the surrounding soil. Rev. Biol. Trop. 54 (1: 49-58. Epub 2006 Mar 31.

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

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S. H Bahari saravi

2013-04-01

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

The Effects of Simultaneous Application of Different Organic and Biological Fertilizers on Quantitative and Qualitative Characteristics of Cucurbita pepo L.

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M Jahan

2013-08-01

Full Text Available Understanding of relations and interactions between ecosystem’s components and plants is one of the main conditions for sustainable production of medicinal plants. To study the effect of simultaneous application of organic and biological fertilizers on yield and yield components of zucchini squash, a split plot arrangement of factors based on randomized complete block design with tree replications was used during 2009-10 growing season. The mainplot factor was the type of organic fertilizers, including 1-cow manure, 2-sheep manure, 3-chicken manure, 4-vermicompost and 5-control. The subplot factor was the biofertilizer (namely Nitragin, containing Azotobacter sp. , Azospirillum sp. and Pseudomonas sp., utilization. The results showed the positive but non significant effect of organic and biological fertilizers on yield and yield components of zucchini squash. Amongst the organic fertilizers, cow and chicken manure, have superiority compared the others. The highest seed oil and protein percent resulted in chicken manure, although there was not significant different between treatments due to seed oil percent. The positive effect of organic and biological fertilizers on seed yield was higher than fruit yield. Positive correlations found between fruit and seed yield, and between one fruit weight and one fruit seed weight (R2=0.72** and 0.56**, respectively. At a glance, cow manure solely application was better than its application with nitragin. Nitragin application has no significant effect on some traits, when utilized with sheep manure and vermicompost. The possibilities of antagonistic effect among organic and biological fertilizers needs to be more studied.

بهینه‌سازی کشت میکروبی پلی‌هیدروکسی بوتیرات توسط میکروارگانیسم Azotobacter Beijerinckii DSMZ-1041

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2013-05-01

Full Text Available در آزمایش‌های به‌عمل آمده در این تحقیق از میکروارگانیسم Azotobacter Beijerinckii DSMZ 1041 که از بانک میکروبی آلمان تهیه شد، استفاده گردید. بر اساس گزارش‌هایی که قبلاً ارایه شده و آزمایش‌های صورت گرفته مشخص شد که این میکروارگانیسم در شرایطی که منبع کربنی به میزان فراوان در محیط موجود بوده و منبع نیتروژنی محدود باشد، قابلیت تجمع گرانول‌های پلی هیدروکسی بوتیرات را دارا است. در این تحقیق منبع نیتروژنی (کلرید آمونیوم با غلظت‌های 5/0 و gr/L 2 و منبع کربنی (گلوکز با غلظت‌های 30، 40، 50 و gr/L 60 مورد استفاده قرار گرفت و تأثیر غلظت‌های این دو ماده بر وزن خشک توده سلولی، میزان مصرف قند توسط میکروارگانیسم و میزان تولید بیوپلیمر بررسی گردید. بیشترین میزان تولید بیوپلیمر در غلظت گلوکز gr/L 60 و کلرید آمونیوم gr/L 5/0 حاصل شد، لازم به ذکر است که غلظت‌های بالاتر گلوکز به علت بازدارندگی، میزان تولید بیوپلیمر را کاهش می‌دهد. بیشترین بازده بیوماس (Yx/s در گلوکز gr/L 30 و کلرید آمونیوم gr/L 2 حاصل شد. بیشترین بازده تولید (Yp/s در گلوکز و کلرید آمونیوم 30 و gr/L 5/0 حاصل شد و حداکثر بهره‌دهی (Qp در گلوکز وکلرید آمونیوم 50 و gr/L 1 حاصل گردید. همچنین میزان بیوپلیمر به دست آمده از روش آزمایشگاهی با روش آماری پاسخ سطح مقایسه شده و دقت آزمایش‌های �

Methylocapsa acidiphila gen. nov., sp. nov., a novel methane-oxidizing and dinitrogen-fixing acidophilic bacterium from Sphagnum bog.

Science.gov (United States)

Dedysh, Svetlana N; Khmelenina, Valentina N; Suzina, Natalia E; Trotsenko, Yuri A; Semrau, Jeremy D; Liesack, Werner; Tiedje, James M

2002-01-01

A novel genus and species, Methylocapsa acidiphila gen. nov., sp. nov., are proposed for a methane-oxidizing bacterium isolated from an acidic Sphagnum peat bog. This bacterium, designated strain B2T, represents aerobic, gram-negative, colourless, non-motile, curved coccoids that form conglomerates covered by an extracellular polysaccharide matrix. The cells use methane and methanol as sole sources of carbon and energy and utilize the serine pathway for carbon assimilation. Strain B2T is a moderately acidophilic organism with growth between pH 4.2 and 7.2 and at temperatures from 10 to 30 degrees C. The cells possess a well-developed system of intracytoplasmic membranes (ICM) packed in parallel on only one side of the cell membrane. This type of ICM structure represents a novel arrangement, which was termed type III. The resting cells are Azotobacter-type cysts. Strain B2T is capable of atmospheric nitrogen fixation; it possesses particulate methane monooxygenase and does not express soluble methane monooxygenase. The major phospholipid fatty acid is 18:1omega7c and the major phospholipids are phosphatidylglycerols. The G+C content of the DNA is 63.1 mol%. This bacterium belongs to the alpha-subclass of the Proteobacteria and is most closely related to the acidophilic methanotroph Methylocella palustris KT (97.3% 16S rDNA sequence similarity). However, the DNA-DNA hybridization value between strain B2T and Methylocella palustris K(T) is only 7%. Thus, strain B2T is proposed to comprise a novel genus and species, Methylocapsa acidiphila gen. nov., sp. nov. Strain B2T (= DSM 13967T = NCIMB 13765T) is the type strain.

Effects of Fertilizer Types and Irrigation Intervals of on Quantity Criteria of Lavender (Lavandula angustifolia, Rosemary (Rosemarinus officinalis and Hyssop (Hyssopus officinalis

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A Koocheki

2012-02-01

Full Text Available In order to investigate the effects of fertilizer types and irrigation regimes on quantitative criteria of three medicinal plants: lavander, rosemary and hyssop, an experiment was conducted at Research Field of Faculty of Agriculture, Ferdowsi University of Mashhad, during two growing years of 2007-2010. A split-split plot design with three replications was used. Treatments were three irrigation intervals (10, 20, 30 days as main plots and three types of fertilizers in six levels: control, Nitroxin containing Azotobacter sp. and Azospirilum sp. (5lit/ha, nitrogen fertilizer (50 and 100 kg/ha, cow manure (10 and 20 ton/ha as subplots. Animal manure and chemical fertilizer were applied at the time of transferring seedlings to the field and Nitroxin was used with the first irrigation. Shoot harvesting was performed twice during the plant growth at the time of full flowering. Increasing irrigation intervals reduced dry matter yield of three species and the highest yield of lavender (3990 kg/ha, rosemary (2380 kg/ha and hyssop (7380 kg/ha were obtained with 10 days interval. Also the effect of fertilizer was not significant but the highest yield for lavender (3930kg/ha, rosemary (2535kg/ha was obtained with 50 kg/ha chemical fertilizer and the highest yield of hyssop (6117kg/ha resulted in application of 20 ton/ha animal manure. The ratio of leaf dry weight to stem dry weight for both years was gained with 30 days irrigation interval at 20 ton/ha animal manure. In general, the best treatment was 30 days interval irrigation and 20 ton/ha animal manure for the best yield and respective in local conditions

Controlled expression of nif and isc iron-sulfur protein maturation components reveals target specificity and limited functional replacement between the two systems.

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Dos Santos, Patricia C; Johnson, Deborah C; Ragle, Brook E; Unciuleac, Mihaela-Carmen; Dean, Dennis R

2007-04-01

The nitrogen-fixing organism Azotobacter vinelandii contains at least two systems that catalyze formation of [Fe-S] clusters. One of these systems is encoded by nif genes, whose products supply [Fe-S] clusters required for maturation of nitrogenase. The other system is encoded by isc genes, whose products are required for maturation of [Fe-S] proteins that participate in general metabolic processes. The two systems are similar in that they include an enzyme for the mobilization of sulfur (NifS or IscS) and an assembly scaffold (NifU or IscU) upon which [Fe-S] clusters are formed. Normal cellular levels of the Nif system, which supplies [Fe-S] clusters for the maturation of nitrogenase, cannot also supply [Fe-S] clusters for the maturation of other cellular [Fe-S] proteins. Conversely, when produced at the normal physiological levels, the Isc system cannot supply [Fe-S] clusters for the maturation of nitrogenase. In the present work we found that such target specificity for IscU can be overcome by elevated production of NifU. We also found that NifU, when expressed at normal levels, is able to partially replace the function of IscU if cells are cultured under low-oxygen-availability conditions. In contrast to the situation with IscU, we could not establish conditions in which the function of IscS could be replaced by NifS. We also found that elevated expression of the Isc components, as a result of deletion of the regulatory iscR gene, improved the capacity for nitrogen-fixing growth of strains deficient in either NifU or NifS.

Effect of diazotrophic bacteria as phosphate solubilizing and indolic compound producers on maize plants

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Mónica Del Pilar López Ortega

2013-07-01

Full Text Available Phosphorus is limiting for growth of maize plants, and because of that use of fertilizers like Rock Phosphate has been proposed. However, direct use of Rock Phosphate is not recommended because of its low availability, so it is necessary to improve it. In this study, a group of diazotrophic bacteria were evaluated as phosphate-solubilizing bacteria, for their production of indolic compounds and for their effects on growth of maize plants. Strains of the genera Azosporillum, Azotobacter, Rhizobium and Klebsiella, were quantitatively evaluated for solubilization of Ca3(PO42 and rock phosphate as a single source of phosphorous in SRS culture media. Additionally, the phosphatase enzyme activity was quantified at pH 5.0, 7.0 and 8.0 using p-nitrophenyl phosphate, and production of indolic compound was determined by colorimetric quantification. The effect of inoculation of bacteria on maize was determined in a completely randomized greenhouse experiment where root and shoot dry weights and phosphorus content were assessed. Results showed that strain C50 produced 107.2 mg .L-1 of available-P after 12 days of fermentation, and AC10 strain had the highest phosphatase activity at pH 8 with 12.7 mg of p-nitrophenol mL .h-1. All strains synthetized indolic compounds, and strain AV5 strain produced the most at 63.03 µg .mL-1. These diazotrophic bacteria increased plant biomass up to 39 % and accumulation of phosphorus by 10%. Hence, use of diazotrphic phosphate-solubilizing bacteria may represent an alternative technology for fertilization systems in maize plants.

Geochemical importance of isotopic fractionation during respiration

International Nuclear Information System (INIS)

Schleser, G.; Foerstel, H.

1975-01-01

In 1935 it was found that atmospheric oxygen contained a relatively greater abundance of the 18 O isotope than did the oxygen bound in water (Dole effect). A major contribution to the fractionation of the stable oxygen isotopes should result from the respiration of microorganisms. In this respect our interest centers on the soil because nearly all organic material produced on land is decomposed within the soil. The oceans are less important because the primary productivity on land is twice the value for the oceans. In a first approach we measured the oxygen isotope fractionation during the respiration of E. coli K12 for different respiration rates. These results, accomplished with a chemostat, indicate that the fractionation factor α of the oxygen isotopes increases with the increasing respiratory activity, measured as Q/sub O 2 /. At low dilution rates or growth rates respectively of about 0.05 h -1 , the fractionation factor amounts to 1.006 increasing to 1.017 at dilution rates of about 1.0 h -1 . The results are interpreted as a kinetic mass fractionation due to the slightly different diffusion coefficients of 16 O 2 and 18 O 16 O. The respiration rates in conjunction with the corresponding fractionation data are compared with the respiration rates of typical soil microorganisms such as Azotobacter, in order to deduce fractionation data for these organisms. This is necessary to calculate a mean global fractionation factor. Understanding the Dole effect with these fractionation processes should finally give us the opportunity to calculate gas-exchange rates between the atmosphere and the oceans, on the basis of the behavior of the stable oxygen isotopes

[Development of a liquid fermentation system and encystment for a nitrogen-fixing bacterium strain having biofertilizer potential].

Science.gov (United States)

Camelo-Rusinque, Mauricio; Moreno-Galván, Andrés; Romero-Perdomo, Felipe; Bonilla-Buitrago, Ruth

The indiscriminate use of chemical fertilizers has contributed to the deterioration of the biological, physical and chemical properties of the soil, resulting in the loss of its productive capacity. For this reason, the use of biofertilizers has emerged as a technological alternative. The objective of this research was to develop a suitable liquid fermentation system and encystment for the multiplication of Azotobacter chroococcum AC1 strain, a bacterium employed in a biofertilizer formulation produced at present by CARPOICA, Colombia. Sequential statistical designs were used to determine the conditions in the fermentation system. The interaction between agitation, aeration and pH was evaluated on the viable biomass (CFU/ml) of AC1. In addition, the encystment ability of the strain was evaluated using two encystment agents and the potential plant growth-promoting rhizobacteria (PGPR) activity was assessed by different techniques, such as nitrogen fixation by ARA, phosphate solubilization by the phospho-molybdenum-blue reaction and indolic compound production by colorimetric reaction using the Salkowski reagent. Results showed significant effects (p<0.05) on the viable biomass in the three conditions (pH, aeration and agitation) tested individually, in one dual interaction and one tripartite interaction, were demonstrated to have a positive effect on the response variable aeration and agitation. The addition of the two encystment agents evaluated, AE01 and AE02, demonstrated the ability of AC1 to form cysts under stress conditions. Likewise, fermentation and encystment conditions did not affect the biological activities tested. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Kajian Penggunaan Pupuk Hayati untuk Mengendalikan Penyakit Akar Gada (Plasmodiophora brassicae pada Tanaman Sawi Daging

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Diding Rachmawati

2016-03-01

Full Text Available Pada budidaya tanaman sawi daging (pakcoi  dijumpai berbagai masalah  serius  yang menghambat upaya peningkatan produksi dan kualitas hasil. Salah satu kendala utama adalah penyakit tular tanah yang disebabkan oleh cendawan Plasmopara brassicae Wor . Serangan patogen tular tanah dapat menekan produksi tanaman hortikultura secara significan. Berbagai upaya telah dilakukan untuk mengendalikan patogen tular tanah antara lain dengan menggunakan bekterisida sistemik . Salah satu alternatif pengendalian yang paling prospektif adalah dengan menggunakan pupuk hayati yang telah diperkaya dengan mikroorganisme. antara lain bakteri selulotik, Azotobacter sp., Azospirillium sp., Rhizobium sp., Pseudomonas sp., Lactobacillus sp., dan  bakteri pelarut fosfat yang bertujuan untuk memperbaiki struktur tanah dan mengendalikan penyakit tular tanah. Penelitian dilakukan di kebun percobaan Karangploso BPTP Jatim,  pada bulan Januari sampai dengan April 2014, menggunakan rancangan acak kelompok, 4 perlakuan dan 6 ulangan. Perlakuan  terdiri dari  : A = Pupuk hayati dosis 15 kg/ha,   B = Pupuk hayati dosis 30 kg/ha,  C = Pupuk hayati dosis 45 kg/ha, D = Cara petani. Tujuan penelitian adalah untuk mengetahui efektifitas pupuk hayati dalam mengendalikan penyakit akar gada  P.brassicae  pada tanaman sawi daging. Hasil penelitian menunjukkan bahwa pemberian pupuk hayati dosis 45 kg/ha dapat memberikan pertumbuhan yang baik terhadap tinggi tanaman ( 26,50 cm, jumlah daun (21 helai, lebar tajuk (33,25 cm, panjang akar (14,38 cm dan bobot/tanaman (380 g/tanaman. Persentase serangan penyakit akar gada terendah juga ditunjukkan oleh pemberian pupuk hayati dosis 45 kg/ha, yaitu sebesar 1,75 % dan penekanan penyakit sebesar 70,83 %.Kata Kunci : Brassica juncea, pupuk hayati, penyakit bengkak akar

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

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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.

Evaluation the effects of organic, biological and chemical fertilizers on morphological traits, yield and yield components of Basil (Ocimum basilicum L.

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S. M.K Tahhami Zarandi

2015-04-01

Full Text Available The use of organic manure and biofertilizers containing beneficial microorganisms instead of chemical fertilizers are known to improve plant growth through supply of plant nutrients and can help sustain environmental health and soil productivity. Because of special priority of the medicinal plants production in sustainable agricultural systems and lack of studies on assessment of different sources of fertilizer on basil plants, an experiment was conducted at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2009. A complete randomize block design with ten treatments, and three replications was used. The treatments were: 1cow manure, 2sheep manure, 3hen manure, 4compost 5vermicompost, 6biological fertilizer nitroxin (consisting of Azotobacter and Azospirillum, 7biological fertilizer consisting of Phosphate Solubilizing Bacteria (Pseudomonas and Bacillus, 8mixture of biological fertilizer nitroxin and Phosphate Solubilizing Bacteria 9NPK fertilizers, and 10control (no fertilizer. Results showed plant height in sheep manure was higher than other treatments. Number of branches in vermicompost and number of inflorescence in cow manure were significantly higher than other treatments. The number of whorled flowers in compost, sheep and cow manure were more than other treatments. Highest leaf and green area index was observed in nitroxin treatment and biological yield in sheep manure have significant difference with other treatments (except cow manure. The highest seed yield were obtained from plants treated with compost (1945 kg/h and the lowest of that observed in NPK fertilizer and control treatments. In all measured traits (except number of inflorescence NPK fertilizer and control treatment did not have any significant difference.

Evaluation of Vermicompost and Nitrogen Biofertilizer Effects on Flowering Shoot Yield, Essential Oil and Mineral Uptake (N, P and K in Summer Savory (Satureja hortensis L.

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Mohammad Reza Haj Seyed Hadi

2018-02-01

(2.01% were obtained by using 10 ton per hectare of vermicompost. Applying 15 ton per hectare of vermicompost caused maximum flowering shoot yield (2237.82kg/ha, nitrogen (2.21% and phosphorus (0.52% content in the aboveground shoot. Mean comparison indicated that seed inoculation with Supernitroplus had significant effects on all measured traits except for nitrogen content in aboveground shoot. The maximum fresh and dry plant weight (40.21 and 14.42g/plant, flowering shoot yield (2406.21kg/ha, essential oil (2.05%, phosphorus (0.49% and potassium (1.34% were obtained by applying Supernitroplus. The maximum nitrogen content (2.23% was obtained by using Nitroxine. Results of interaction effects showed that using supernitroplus and 15 ton per hectare of vermicompost caused maximum potassium content (1.50% in Savory shoots. Several types of studies have shown a beneficial effect on crop plants by inoculation of seeds with Azospirillum and Azotobacter strains. Inoculation of plants with Azospirillum and Azotobacter can results in significant changes in various plant growth parameters. Positive effects of inoculation have been demonstrated on including increase in root length and nutrition (NO3- , NH4+, P042- , K +, Rb+ and Fe++ uptake. Nitrogen and phosphorus are the two major plant nutrients and combined inoculation of nitrogen fixers and PSM may benefit the plants better than either group of organisms alone. Interaction studies have been done both in vitro and in vivo. Nitrogen fixers and PSM when inoculated together colonized the rhizosphere and enhanced the growth of crops by providing it with nitrogen and phosphate, respectively. Vermicompost contains most of the plant nutrients such as nitrate, phosphates, exchangeable calcium and soluble potassium, and microelements which result in improved plant growth and development and is responsible for increased qualitative and quantitative yield of many crops. Conclusion The results of current experiment showed that

Bionota: Bacterias promotoras de crecimiento de microalgas: una nueva aproximación en el tratamiento de aguas residuales Microalgae growth-promoting bacteria: A novel approach in wastewater treatment

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Bashan Yoav

2003-12-01

Full Text Available Las bacterias promotoras de crecimiento en plantas (PGPB del género Azospirillum son conocidas porque mejo­ran el crecimiento de numerosas cosechas agrícolas; sin embargo, el presente trabajo pretende extender el uso de estas bacterias a "bacterias promotoras de crecimiento de microalgas" (MPGB para aumentar la capacidad de las microalgas de eliminar nutrientes de aguas residuales. La inoculación deliberada de las microalgas Chlorella spp. con PGPB de origen terrestre no ha sido reportada con anterioridad, tal vez debido al origen diferente de estos dos microorganismos. Al inmovilizar de manera conjunta Chlorella vulgaris y Azospirillum brasilense Cd en esferas de alginato, se obtuvo como resultado un aumento significativo en varios parámetros de crecimiento de la microalga, como el peso fresco y seco, el número total de células, el tamaño de las colonias de microalgas dentro de la esfera, el número de organismos por colonia y la concentración de pigmentos. Además, aumenta­ron los lípidos y la variedad de ácidos grasos. La microalga combinada con la MGPB tiene una mayor capacidad de eliminar amonio y fósforo tanto en agua residual sintética como en agua residual doméstica. Actualmente se ha estado experimentando con otras PGPB (Flavobacterium sp. Azospirillum sp. y Azotobacter sp. para propósitos acuícolas; por ejemplo aumentar el crecimiento de fitoplancton utilizado en el cultivo de carpas y estabilizar cultivos masivos de microalgas marinas utilizadas como alimento para organismos marinos, todo esto con resul­tados promisorios. Si bien el efecto de las PGPB en microorganismos acuáticos aún no ha sido suficientemente explorado, proponemos que la co-inmovilización de microalgas y bacterias promotoras de crecimiento es un medio efectivo para aumentar la población microalgal y también su capacidad de limpiar aguas residuales. Palabras clave: PGPB; microalgas; biotratamiento de aguas residuales; co

Potencial biofertilizante de bacterias diazótrofas aisladas de muestras de suelo rizosférico

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Laura Y Moreno

Full Text Available Las bacterias promotoras del crecimiento vegetal son capaces de adaptarse, colonizar y persistir en la rizosfera de la planta, lo cual favorece su crecimiento y desarrollo. En este trabajo se aislaron 32 cepas nativas de bacterias diazótrofas, a partir de muestras de suelo rizosférico de diferentes cultivos, identificadas mediante los medios de cultivo tradicionales y el sistema BBL CRYSTAL. La identificación bioquímica se realizó a través de la reacción en cadena de la polimerasa (PCR, del inglés Polymerase Chain Reaction. Nueve aislados se determinaron como Stenotrophomonas maltophilia y uno como Azotobacter vinelandii, de los cuales tres coincidieron en la identificación bioquímica y la molecular. Se realizó un ensayo en invernadero para evaluar el efecto fertilizante en plantas de maíz, según un diseño experimental de bloques al azar y nueve tratamientos, por triplicado: tratamiento 1: A. vinelandii ATCC 9046; tratamientos del 2 al 7 para los seis aislados; tratamiento 8 para fertilización química; y tratamiento 9 para suelo sin fertilización (testigo. Los aislados M8-10, M10-1 y M11-3, identificados como S. maltophilia por PCR, tuvieron mejores resultados en la emergencia de las plantas, el diámetro del tallo y la longitud de las hojas y los tallos. Finalmente se determinó que M10-1 mostró valores de emergencia y crecimiento de la planta por encima de la media y el límite superior, con respecto a los demás aislados y controles, lo cual lo convierte en un potencial biofertilizante.

Medio de cultivo utilizando residuos-sólidos para el crecimiento de una bacteria nativa con potencial biofertilizante

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Cecilia Lara Mantilla

2010-01-01

Full Text Available En el presente trabajo se muestran los resultados obtenidos de la evaluación del crecimiento, desarrollo y viabilidad de una cepa bacteriana nativa Azotobacter A15M2G con potencial biofertilizante, sobre un medio de cultivo preparado con residuos sólidos vegetales procedentes del mercado: Brassica Oleracea (repollo, Lactusa sativa (lechuga y Allium fistulosum (cebollín. El crecimiento de la bacteria en el medio de residuo vegetal a diferentes concentraciones: 25, 50 y 75% p/v fue evaluado, encontrándose un mejor crecimiento en la concentración del 25%; la caracterización química del medio de cultivo al 25% p/v, después de ser esterilizado, mostró los siguientes valores: 0,035% de carbohidratos, 0,4044% de proteína, 0,03574% de cenizas, 99,3955% de humedad, 6,93 mg/l de azufre, 0,170 mg/l de fósforo, 0,2 mg/l de manganeso, 409,2 mg/l de potasio, 1,842 mg/l de hierro, 14 mg/l de sodio y 0,1 mg/l de zinc, 28,056 mg/l de calcio y 17,017 mg/l de magnesio. En el medio de cultivo al 25% también fue evaluada la capacidad fijadora de nitrógeno y productora de ácido indol acético (AIA de la bacteria, obteniendo una concentración de 4,8725 mg/l y 13,5837 mg/l respectivamente. Posteriormente se realizó un ensayo de viabilidad por un periodo de 2 meses. Los resultados muestran que los residuos-sólidos vegetales generados en las plazas de mercado local pueden ser utilizados como medio de cultivo ofreciendo un aporte nutricional al microorganismo de interés agrícola minimizando la contaminación ambiental generada.

The effects of arbuscular mycorrhizal fungus and free living nitrogen fixing bacteria on growth, photosynthesis and yield of corn

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mohsen jahan

2009-06-01

Full Text Available In recent years, biological fertilizers have received special attention by scientists in sustainable and low input agriculture. In order to study the effects of arbuscular mycorrhizal fungi and free living nitrogen fixing bacteria on growth and photosynthesis characteristics of corn in conventional and ecological cropping systems, a field experiment was conducted at the Research Farm of Ferdowsi University of Mashhad during year 2006. A split plots arrangement based on randomized complete block design with three replications was used. Treatments consisted four cropping systems (1- High input conventional system, 2- Medium input conventional system, 3- Low input conventional system and 4- Ecological system and four inoculations (1- Mycorrhiza fungus, Glomus intraradices, 2- Bacteria, Azotobacter paspali and Azospirillum brasilense, 3- Dual inoculation, Fungus plus bacteria, and 4- No-inoculation, control, which were allocated to main plots and sub plots, respectively. All agronomic practices and inputs application during planting and nursing for each of cropping systems were conducted according to regional traditions. Results showed that the effect of inoculation on photosynthesis rates of corn was significant, as the highest photosynthesis rate obtained in dual inoculation. Single inoculation (fungus or bacteria was ranked second. The effect of all inoculations on corn dry matter production was significant and dual inoculation produced the highest dry matter yield. The cropping systems have significant effect on corn yield and the difference between medium input conventional system and high input conventional system was significant, but the high input, low input and ecological cropping systems showed no differences. Inoculants affected the SPAD readings, and dual inoculation showed the highest SPAD readings. This study showed that utilization of low input conventional and ecological systems in combination with use of dual inoculation of

Characterization of the Paenibacillus beijingensis DSM 24997 GtfD and its glucan polymer products representing a new glycoside hydrolase 70 subfamily of 4,6-α-glucanotransferase enzymes.

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Joana Gangoiti

Full Text Available Previously we have reported that the Gram-negative bacterium Azotobacter chroococcum NCIMB 8003 uses the 4,6-α-glucanotransferase GtfD to convert maltodextrins and starch into a reuteran-like polymer consisting of (α1→4 glucan chains connected by alternating (α1→4/(α1→6 linkages and (α1→4,6 branching points. This enzyme constituted the single evidence for this reaction and product specificity in the GH70 family, mostly containing glucansucrases encoded by lactic acid bacteria (http://www.CAZy.org. In this work, 4 additional GtfD-like proteins were identified in taxonomically diverse plant-associated bacteria forming a new GH70 subfamily with intermediate characteristics between the evolutionary related GH13 and GH70 families. The GtfD enzyme encoded by Paenibacillus beijingensis DSM 24997 was characterized providing the first example of a reuteran-like polymer synthesizing 4,6-α-glucanotransferase in a Gram-positive bacterium. Whereas the A. chroococcum GtfD activity on amylose resulted in the synthesis of a high molecular polymer, in addition to maltose and other small oligosaccharides, two reuteran-like polymer distributions are produced by P. beijingensis GtfD: a high-molecular mass polymer and a low-molecular mass polymer with an average Mw of 27 MDa and 19 kDa, respectively. Compared to the A. chroooccum GtfD product, both P. beijingensis GtfD polymers contain longer linear (α1→4 sequences in their structure reflecting a preference for transfer of even longer glucan chains by this enzyme. Overall, this study provides new insights into the evolutionary history of GH70 enzymes, and enlarges the diversity of natural enzymes that can be applied for modification of the starch present in food into less and/or more slowly digestible carbohydrate structures.

Microalgae growth-promoting bacteria: A novel approach in wastewater treatment

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Luz E. de-Bashan

2003-07-01

Full Text Available Plant growth-promoting bacteria (PGPB from the genus Azospirillum are known to enhance the growth of numerous agricultural crops. The use of these bacteria is proposed as "micro-algae-growth promoting bacteria" (MGPB for enhancing freshwater micro-algae Chlorella vulgaris and C. sorokiniana capadty to clean polluted water. The deliberate inoculation of Chlorella sp. with a terrestrial PGPB has not been reported prior to these studies, perhaps because of the different origin of the two micro-organisms. Chlorella spp. is not known to harbour any plant growth-promoting bacteria and Azospirillum sp. is rarely used for inoculation in aquatic environments. Co-immobilisation of C. vulgaris and A. brasilense Cd in small alginate beads resulted in significant increases in numerous micro-algae growth parameters. Dry and fresh weight, total number of cells, micro-algal cluster (colonies size within the bead, number of micro-algal cells per cluster and micro-algal pigments levels significantly increased. Lipids and the variety of fatty adds also significantly increased, as did the combination of micro-algae. MGPB had superior capacity for removing ammonium and phosphorus from polluted synthetic and municipal wastewaters than the micro-algae by itself. Other PGPB (i.e. Flavobacterium sp. Azospirillum sp. and Azotobacter sp. are currently being tested in aquaculture; carp farming using enhanced phytoplankton growth and stabilising mass marine micro-algae culture for use as feed for marine organisms are both retuming promising results. This aspect of PGPB effect on water micro-organisms is currently in its infancy. We pro pose that co-immobilising micro-algae and plant growth-promoting bacteria represent an effective means of increasing micro-algal populations and also their capacity for cleaning polluted water. Key words: PGPB; micro-algae; wastewater treatment; co-immobilised

Review: Biological fertilization and its effect on medicinal and aromatic plants

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KHALID ALI KHALID

2012-11-01

Full Text Available Khalid KA. 2012. Review: Biological fertilization and its effect on medicinal and aromatic plants. Nusantara Bioscience 4: 124-133. The need of increase food production in the most of developing countries becomes an ultimate goal to meet the dramatic expansion of their population. However, this is also associated many cases with a reduction of the areas of arable land which leaves no opinion for farmers but to increase the yield per unit area through the use of improved the crop varieties, irrigation and fertilization. The major problem facing the farmer is that he cannot afford the cost of these goods, particularly that of chemical fertilizers. Moreover, in countries where fertilizer production relies on imported raw materials, the costs are even higher for farmer and for the country. Besides this, chemical fertilizers production and utilization are considered as air, soil and water polluting operations. The utilization of bio-fertilizers is considered today by many scientists as a promising alternative, particularly for developing countries. Bio-fertilization is generally based on altering the rhizosphere flora, by seed or soil inoculation with certain organisms, capable of inducing beneficial effects on a compatible host. Bio-fertilizers mainly comprise nitrogen fixes (Rhizobium, Azotobacter, Azospirellum, Azolla or blue green algae, phosphate dissolvers or vesicular-arbuscular mycorrhizas and silicate bacteria. These organisms may affect their host plant by one or more mechanisms such as nitrogen fixation, production of growth promoting substances or organic acids, enhancing nutrient uptake or protection against plant pathogens. Growth characters, yield, essential oil and its constituents, fixed oil, carbohydrates, soluble sugars and nutrients contents of medicinal and aromatic plants were significantly affected by adding the biological fertilizers compared with recommended chemical fertilizers.

APLIKASI KOMBINASI KOMPOS JERAMI, KOMPOS AZOLLA DAN PUPUK HAYATI UNTUK MENINGKATKAN JUMLAH POPULASI BAKTERI PENAMBAT NITROGEN DAN PRODUKTIVITAS TANAMAN PADI BERRBASIS IPAT-BO

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Ferina Rosiana

2013-03-01

Full Text Available Penelitian untuk mengetahui efek pemberian kombinasi kompos jerami dengan Azolla dan pupuk hayati majemuk terhadap peningkatan populasi bakteri penambat N dan produktivitas tanaman padi dengan teknologi IPAT-BO dilaksanakan dari bulan April hingga Juli 2012 di kebun percobaan Fakultas Pertanian, Universitas Padjadjaran, Jatinangor, dengan ketinggian + 740 m dpl. Penelitian ini menggunakan rancangan acak kelompok faktor tunggal dengan dua belas perlakuan dan tiga kali ulangan. Perlakuan terdiri dari (A tanpa kompos jerami, (B kompos jerami 2,5 ton ha-1, (C kompos jerami 5 ton ha-1, (D kompos Azolla 0,5 ton ha-1, (E kompos jerami 2,5 ton ha-1 + kompos Azolla 0,5 ton ha-1, (F kompos jerami 5 ton ha-1 + kompos Azolla 0,5 ton ha-1, (G pupuk hayati 400 g ha-1, (H kompos jerami 2,5 ton ha-1 + pupuk hayati 400 g ha-1, (I kompos jerami 5 ton ha-1 + pupuk hayati 400 g ha-1, (J kompos Azolla 0,5 ton ha-1 + pupuk hayati 400 g ha-1, (K kompos jerami 2,5 ton ha-1 + kompos Azolla 0,5 ton ha-1 + pupuk hayati 400 g ha-1, (L kompos jerami 5 ton ha-1 + kompos Azolla 0,5 ton ha-1 + pupuk hayati 400 g ha-1.Aplikasi perlakuan kompos jerami, kompos Azolla dan pupuk hayati majemuk memberikan pengaruh terhadap populasi penambat N (Azotobacter sp. dan Azospirilium sp. dan produktifitas tanaman padi. Aplikasi kompos jerami 2,5 ton ha-1 dengan pupuk hayati 400 g ha-1 memberikan hasil GKP yaitu 64,39 g tanaman-1 (6,13 ton ha-1. Kata kunci: IPAT-BO, kompos Azolla, kompos jerami, pupuk hayati.

Metabolic engineering of a diazotrophic bacterium improves ammonium release and biofertilization of plants and microalgae.

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Ambrosio, Rafael; Ortiz-Marquez, Juan Cesar Federico; Curatti, Leonardo

2017-03-01

The biological nitrogen fixation carried out by some Bacteria and Archaea is one of the most attractive alternatives to synthetic nitrogen fertilizers. However, with the exception of the symbiotic rhizobia-legumes system, progress towards a more extensive realization of this goal has been slow. In this study we manipulated the endogenous regulation of both nitrogen fixation and assimilation in the aerobic bacterium Azotobacter vinelandii. Substituting an exogenously inducible promoter for the native promoter of glutamine synthetase produced conditional lethal mutant strains unable to grow diazotrophically in the absence of the inducer. This mutant phenotype could be reverted in a double mutant strain bearing a deletion in the nifL gene that resulted in constitutive expression of nif genes and increased production of ammonium. Under GS non-inducing conditions both the single and the double mutant strains consistently released very high levels of ammonium (>20mM) into the growth medium. The double mutant strain grew and excreted high levels of ammonium under a wider range of concentrations of the inducer than the single mutant strain. Induced mutant cells could be loaded with glutamine synthetase at different levels, which resulted in different patterns of extracellular ammonium accumulation afterwards. Inoculation of the engineered bacteria into a microalgal culture in the absence of sources of C and N other than N 2 and CO 2 from the air, resulted in a strong proliferation of microalgae that was suppressed upon addition of the inducer. Both single and double mutant strains also promoted growth of cucumber plants in the absence of added N-fertilizer, while this property was only marginal in the parental strain. This study provides a simple synthetic genetic circuit that might inspire engineering of optimized inoculants that efficiently channel N 2 from the air into crops. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All

Breaking continuous potato cropping with legumes improves soil microbial communities, enzyme activities and tuber yield

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Qin, Shuhao; Yeboah, Stephen; Cao, Li; Zhang, Junlian; Shi, Shangli; Liu, Yuhui

2017-01-01

This study was conducted to explore the changes in soil microbial populations, enzyme activity, and tuber yield under the rotation sequences of Potato–Common vetch (P–C), Potato–Black medic (P–B) and Potato–Longdong alfalfa (P–L) in a semi–arid area of China. The study also determined the effects of continuous potato cropping (without legumes) on the above mentioned soil properties and yield. The number of bacteria increased significantly (p continuous cropping soils, respectively compared to P–C rotation. The highest fungi/bacteria ratio was found in P–C (0.218), followed by P–L (0.184) and then P–B (0.137) rotation over the different cropping years. In the continuous potato cropping soils, the greatest fungi/bacteria ratio was recorded in the 4–year (0.4067) and 7–year (0.4238) cropping soils and these were significantly higher than 1–year (0.3041), 2–year (0.2545) and 3–year (0.3030) cropping soils. Generally, actinomycetes numbers followed the trend P–L>P–C>P–B. The P–L rotation increased aerobic azotobacters in 2–year (by 26% and 18%) and 4–year (40% and 21%) continuous cropping soils compared to P–C and P–B rotation, respectively. Generally, the highest urease and alkaline phosphate activity, respectively, were observed in P–C (55.77 mg g–1) and (27.71 mg g–1), followed by P–B (50.72 mg mg–1) and (25.64 mg g–1) and then P–L (41.61 mg g–1) and (23.26 mg g–1) rotation. Soil urease, alkaline phosphatase and hydrogen peroxidase activities decreased with increasing years of continuous potato cropping. On average, the P–B rotation significantly increased (p improve soil biology environment, alleviate continuous cropping obstacle and increase potato tuber yield in semi–arid region. PMID:28463981

Grain, milling, and head rice yields as affected by nitrogen rate and bio-fertilizer application

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Saeed FIROUZI

2015-11-01

Full Text Available To evaluate the effects of nitrogen rate and bio-fertilizer application on grain, milling, and head rice yields, a field experiment was conducted at Rice Research Station of Tonekabon, Iran, in 2013. The experimental design was a factorial treatment arrangement in a randomized complete block with three replicates. Factors were three N rates (0, 75, and 150 kg ha-1 and two bio-fertilizer applications (inoculation and uninoculation with Nitroxin, a liquid bio-fertilizer containing Azospirillum spp. and Azotobacter spp. bacteria. Analysis of variance showed that rice grain yield, panicle number per m2, grain number per panicle, flag leaves area, biological yield, grains N concentration and uptake, grain protein concentration, and head rice yield were significantly affected by N rate, while bio-fertilizer application had significant effect on rice grain yield, grain number per panicle, flag leaves area, biological yield, harvest index, grains N concentration and uptake, and grain protein concentration. Results showed that regardless of bio-fertilizer application, rice grain and biological yields were significantly increased as N application rate increased from 0 to 75 kg ha-1, but did not significantly increase at the higher N rate (150 kg ha-1. Grain yield was significantly increased following bio-fertilizer application when averaged across N rates. Grains N concentration and uptake were significantly increased as N rate increased up to 75 kg ha-1, but further increases in N rate had no significant effect on these traits. Bio-fertilizer application increased significantly grains N concentration and uptake, when averaged across N rates. Regardless of bio-fertilizer application, head rice yield was significantly increased from 56 % to 60 % when N rate increased from 0 to 150 kg ha-1. Therefore, this experiment illustrated that rice grain and head yields increased with increasing N rate, while bio-fertilizer application increased only rice grain

Alginate-modifying enzymes: Biological roles and biotechnological uses

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Helga eErtesvåg

2015-05-01

Full Text Available Alginate denotes a group of industrially important 1-4-linked biopolymers composed of the C-5-epimers β-D-mannuronic acid (M and α-L-guluronic acid (G. The polysaccharide is manufactured from brown algae where it constitutes the main structural cell wall polymer. The physical properties of a given alginate molecule, e.g. gel-strength, water-binding capacity, viscosity and biocompatibility, are determined by polymer length, the relative amount and distribution of G residues and the acetyl content, all of which are controlled by alginate modifying enzymes. Alginate has also been isolated from some bacteria belonging to the genera Pseudomonas and Azotobacter, and bacterially synthesized alginate may be O-acetylated at O-2 and/or O-3. Initially, alginate is synthesized as polymannuronic acid, and some M residues are subsequently epimerized to G residues. In bacteria a mannuronan C-5-epimerase (AlgG and an alginate acetylase (AlgX are integral parts of the protein complex necessary for alginate polymerisation and export. All alginate-producing bacteria use periplasmic alginate lyases to remove alginate molecules aberrantly released to the periplasm. Alginate lyases are also produced by organisms that utilize alginate as carbon source. Most alginate-producing organisms encode more than one mannuronan C-5 epimerase, each introducing its specific pattern of G residues. Acetylation protects against further epimerization and from most alginate lyases. One enzyme with alginate deacetylase activity from Pseudomonas syringae has been reported. Functional and structural studies reveal that alginate lyases and epimerases have related enzyme mechanisms and catalytic sites. Alginate lyases are now utilized as tools for alginate characterization. Secreted epimerases have been shown to function well in vitro, and have been engineered further in order to obtain enzymes that can provide alginates with new and desired properties for use in medical and

Chestnut green waste composting for sustainable forest management: Microbiota dynamics and impact on plant disease control.

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Ventorino, Valeria; Parillo, Rita; Testa, Antonino; Viscardi, Sharon; Espresso, Francesco; Pepe, Olimpia

2016-01-15

Making compost from chestnut lignocellulosic waste is a possible sustainable management strategy for forests that employs a high-quality renewable organic resource. Characterization of the microbiota involved in composting is essential to better understand the entire process as well as the properties of the final product. Therefore, this study investigated the microbial communities involved in the composting of chestnut residues obtained from tree cleaning and pruning. The culture-independent approach taken highlighted the fact that the microbiota varied only slightly during the process, with the exception of those of the starting substrate and mature compost. The statistical analysis indicated that most of the bacterial and fungal species in the chestnut compost persisted during composting. The dominant microbial population detected during the process belonged to genera known to degrade recalcitrant lignocellulosic materials. Specifically, we identified fungal genera, such as Penicillium, Fusarium, Cladosporium, Aspergillus and Mucor, and prokaryotic species affiliated with Bacilli, Actinobacteria, Flavobacteria and γ-Proteobacteria. The suppressive properties of compost supplements for the biocontrol of Sclerotinia minor and Rhizoctonia solani were also investigated. Compared to pure substrate, the addition of compost to the peat-based growth substrates resulted in a significant reduction of disease in tomato plants of up to 70 % or 51 % in the presence of Sclerotinia minor or Rhizoctonia solani, respectively. The obtained results were related to the presence of putative bio-control agents and plant growth-promoting rhizobacteria belonging to the genera Azotobacter, Pseudomonas, Stenotrophomonas, Bacillus, Flavobacterium, Streptomyces and Actinomyces in the chestnut compost. The composting of chestnut waste may represent a sustainable agricultural practice for disposing of lignocellulosic waste by transforming it into green waste compost that can be used to

ProClaT, a new bioinformatics tool for in silico protein reclassification: case study of DraB, a protein coded from the draTGB operon in Azospirillum brasilense.

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Rubel, Elisa Terumi; Raittz, Roberto Tadeu; Coimbra, Nilson Antonio da Rocha; Gehlen, Michelly Alves Coutinho; Pedrosa, Fábio de Oliveira

2016-12-15

Azopirillum brasilense is a plant-growth promoting nitrogen-fixing bacteria that is used as bio-fertilizer in agriculture. Since nitrogen fixation has a high-energy demand, the reduction of N 2 to NH 4 + by nitrogenase occurs only under limiting conditions of NH 4 + and O 2 . Moreover, the synthesis and activity of nitrogenase is highly regulated to prevent energy waste. In A. brasilense nitrogenase activity is regulated by the products of draG and draT. The product of the draB gene, located downstream in the draTGB operon, may be involved in the regulation of nitrogenase activity by an, as yet, unknown mechanism. A deep in silico analysis of the product of draB was undertaken aiming at suggesting its possible function and involvement with DraT and DraG in the regulation of nitrogenase activity in A. brasilense. In this work, we present a new artificial intelligence strategy for protein classification, named ProClaT. The features used by the pattern recognition model were derived from the primary structure of the DraB homologous proteins, calculated by a ProClaT internal algorithm. ProClaT was applied to this case study and the results revealed that the A. brasilense draB gene codes for a protein highly similar to the nitrogenase associated NifO protein of Azotobacter vinelandii. This tool allowed the reclassification of DraB/NifO homologous proteins, hypothetical, conserved hypothetical and those annotated as putative arsenate reductase, ArsC, as NifO-like. An analysis of co-occurrence of draB, draT, draG and of other nif genes was performed, suggesting the involvement of draB (nifO) in nitrogen fixation, however, without the definition of a specific function.

Actinorhizal Alder Phytostabilization Alters Microbial Community Dynamics in Gold Mine Waste Rock from Northern Quebec: A Greenhouse Study.

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Katrina L Callender

Full Text Available Phytotechnologies are rapidly replacing conventional ex-situ remediation techniques as they have the added benefit of restoring aesthetic value, important in the reclamation of mine sites. Alders are pioneer species that can tolerate and proliferate in nutrient-poor, contaminated environments, largely due to symbiotic root associations with the N2-fixing bacteria, Frankia and ectomycorrhizal (ECM fungi. In this study, we investigated the growth of two Frankia-inoculated (actinorhizal alder species, A. crispa and A. glutinosa, in gold mine waste rock from northern Quebec. Alder species had similar survival rates and positively impacted soil quality and physico-chemical properties in similar ways, restoring soil pH to neutrality and reducing extractable metals up to two-fold, while not hyperaccumulating them into above-ground plant biomass. A. glutinosa outperformed A. crispa in terms of growth, as estimated by the seedling volume index (SVI, and root length. Pyrosequencing of the bacterial 16S rRNA gene for bacteria and the ribosomal internal transcribed spacer (ITS region for fungi provided a comprehensive, direct characterization of microbial communities in gold mine waste rock and fine tailings. Plant- and treatment-specific shifts in soil microbial community compositions were observed in planted mine residues. Shannon diversity and the abundance of microbes involved in key ecosystem processes such as contaminant degradation (Sphingomonas, Sphingobium and Pseudomonas, metal sequestration (Brevundimonas and Caulobacter and N2-fixation (Azotobacter, Mesorhizobium, Rhizobium and Pseudomonas increased over time, i.e., as plants established in mine waste rock. Acetate mineralization and most probable number (MPN assays showed that revegetation positively stimulated both bulk and rhizosphere communities, increasing microbial density (biomass increase of 2 orders of magnitude and mineralization (five-fold. Genomic techniques proved useful in

The effect of plant growth promoting rhizobacteria (PGPR on quantitative and qualitative characteristics of Sesamum indicum L. with application of cover crops of Lathyrus sp. and Persian clover (Trifolium resopinatum L.

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M. Jahan

2016-05-01

Full Text Available Cover crops cultivation and application of plant growth rhizobacteria are the key factors to enhance agroecosystem health. A field experiment was conducted at the Research Farm of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2009-2010. A split plot arrangement based on a complete randomized block design with three replications was used. Cultivation and no cultivation of Lathyrus sp. and Persian clover (Trifolium resopinatum in autumn assigned to the main plots. The sub plot factor consisted of three different types of biofertilizers plus control, including 1-nitroxin (containing of Azotobacter sp. and Azospirillum sp., 2- phosphate solubilizing bacteria (PSB (containing of Bacillus sp. and Pseudomonas sp., 3- biosulfur (containing of Thiobacillus ssp. and 4- control (no fertilizer. The results showed the effect of cover crops on seed number and seed weight per plant, biological and seed yield was significant, as the seed yield increased of 9 %. In general, biofertilizers showed superiority due to the most studied traits compared to control. Nitroxin, PSB and biosulfur increased biological yield of 44, 28 and 26 % compared to control, respectively. Cover crops and biofertilizers interactions, showed significant effect on all studied traits, as the highest and the lowest harvest index resulted in cover crop combined with biofertilizers (22.1% and cultivation and no cultivation of cover crops combined with control (15.3%, respectively. The highest seed oil and protein content resulted from cover crops plus biofertilizers (42.4% and cover crops plus PSB (22.5%, respectively. In general, the results showed cover crops cultivation in combination with biofertilizers application could be an ecological alternative for chemical fertilizers, in addition of achieving advantages of cover crops. According to the results, it should be possible to design an ecological cropping system and produce appropriate and healthy

Diversity and seasonal fluctuation of predominant microbial communities in Bhitarkanika, a tropical mangrove ecosystem in India

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Rashmi Ranjan Mishra

2012-06-01

Full Text Available Different groups of microorganisms are present in mangrove areas, and they perform complex interactions for nutrient and ecological balances. Since little is known about microbial populations in mangroves, this study analyzed the microbial community structure and function in relation to soil physico-chemical properties in Bhitarkanika, a tropical mangrove ecosystem in India. Spatial and seasonal fluctuations of thirteen important groups of microorganisms were evaluated from the mangrove forest sediments during different seasons, along with soil physico-chemical parameters. The overall microbial load (x10(5cfu/g soil in soil declined in the order of heterotrophic, free living N2 fixing, Gram-negative nitrifying, sulphur oxidizing, Gram-positive, spore forming, denitrifying, anaerobic, phosphate solubilizing, cellulose degrading bacteria, fungi and actinomycetes. Populations of the heterotrophic, phosphate solubilizing, sulphur oxidizing bacteria and fungi were more represented in the rainy season, while, Gram-negative, Gram-positive, nitrifying, denitrifying, cellulose decomposing bacteria and actinomycetes in the winter season. The pool size of most of other microbes either declined or maintained throughout the season. Soil nutrients such as N, P, K (Kg/ha and total C (% contents were higher in the rainy season and they did not follow any common trend of changes throughout the study period. Soil pH and salinity (mS/cm varied from 6-8 and 6.4-19.5, respectively, and they normally affected the microbial population dynamics. Determination of bacterial diversity in Bhitarkanika mangrove soil by culture method showed the predominance of bacterial genera such as Bacillus, Pseudomonas, Desulfotomaculum, Desulfovibrio, Desulfomonas, Methylococcus, Vibrio, Micrococcus, Klebsiella and Azotobacter. Principal component analysis (PCA revealed a correlation among local environmental variables with the sampling locations on the microbial community in the

Comparing Different Soil Fertility Systems on Some Physiological Characteristics, Yield and Essential Oil of Sage (Salvia officinalis L. under Different Irrigation Regimes

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Mostafa Govahi

2017-10-01

Full Text Available Introduction Sage is a popular medicinal plant which is widely used in food and pharmaceutical industries. Vermicompost are a rich source of macronutrients, micronutrients, vitamins, enzymes and plant growth promoter hormones. Therefore, the use of vermicompost in sustainable agriculture, in addition to increasing population and activity of beneficial soil microorganisms, causes the rapid growth of medicinal plants. The uses of bacteria (Azotobacter, Azospirillum and Pseudomonas as a biofertilizer have causes increasing the efficiency of nitrogen and phosphorus fertilizers and improving the growth of several crops. Drought stress is one of the most important environmental stresses that affect the growth and yield of plants. Management of nutrients in plants, especially during drought conditions and to assess this management on quantity and quality of sage medicinal plant is very important. Limited information are available about the response of sage under water deficiency conditions in different fertilizing systems, so the aim of this research was to study the growth, yield and essential oil production of Sage under different irrigation regimes. Materials and methods Field experiments were carried out at the field research station of Faculty of Agriculture of Tarbiat Modares University in Tehran, Iran during two growing seasons (2011-2012 and 2012-2013. The experiment was laid out in split plot based on randomized complete block design with three replications. Three irrigation levels including irrigation after depletion of 40% available water (I1, irrigation after depletion of 60% available water (I2, irrigation after depletion of 80% available water (I3 as the main plots and five different soil fertility systems including control (no fertilizer (F0, chemical fertilizer (urea=150 kg/ha-1¬¬ (Ur, nitrogen fixing bacteria(Azotobacter+Azospirillum+Pseudomonas (NFB, vermicompost (8 t/ha-1 (V vermicompost + nitrogen fixing bacteria (V+NFB as sub

Effect of Different Levels of Nitroxin and Humic Acid on Quantitative Properties and Essential Oil of Ajowan (Carum copticum (L. C. B. Clarke

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K. Barghamadi

2016-02-01

Full Text Available Introduction: Unbalanced application of fertilizer and chemical pesticides reduce soil fertility and agricultural products quality. Application of bio-fertilizers is quite important for sustainable agriculture..According to the principles of ecological agriculture, soil fertility and plant nutrition play an important role in improving the yield and quality of medicinal plants. The use of biological fertilizers is one of the main strategies in ecological agriculture for plant nutrition. Organic materials are not the only source of bio-fertilizer but bacterial and fungal particles and materials from their activities in relation to nitrogen, phosphorus and other nutrients are examples of biological fertilizers too. Today particular attention has been paid to the canvas of biological nitrogen fixation byfree-living bacteria such as Azospirillum and Azotobacter companion agricultural systems. Nitrogen is mainly the first nutrient which its deficiency in the arid and semi-aridoccurs.It is due to this fact thatthe amount of organic matter that is the major source of nitrogen stored in these areas is negligible. Nitroxin contains the most effective nitrogen fixation bacteria (Azotobacter and Azospirillum. Nitroxin bacteria besides nitrogen fixation of atmosphere and counterbalance of macronutrients and micro nutrientsare required for plant uptake, with the synthesis and secretion of various hormones and growth regulators such as auxin (IAA, the secretion of various amino acids, antibiotics, andhydrogen cyanide hydrogen will cause siderophore growth and development of roots and aerial parts of the plant. Due to environmental concerns, the use of organic acids to improve the quality and quantity of crops and gardens is not possible. Small amounts of organic acids have significant impacts on physical characteristics, chemical and biological soil because of the useful hormonal effects of compounds in increasing production and improving the quality of

Characterization of N2-fixing plant growth promoting endophytic and epiphytic bacterial community of Indian cultivated and wild rice (Oryza spp.) genotypes.

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Banik, Avishek; Mukhopadhaya, Subhra Kanti; Dangar, Tushar Kanti

2016-03-01

The diversity of endophytic and epiphytic diazotrophs in different parts of rice plants has specificity to the niche (i.e. leaf, stem and root) of different genotypes and nutrient availability of the organ. Inoculation of the indigenous, polyvalent diazotrophs can facilitate and sustain production of non-leguminous crops like rice. Therefore, N2-fixing plant growth promoting bacteria (PGPB) were isolated from different parts of three Indian cultivated [Oryza sativa L. var. Sabita (semi deep/deep water)/Swarna (rain fed shallow lowland)/Swarna-Sub1(submergence tolerant)] and a wild (O. eichingeri) rice genotypes which respond differentially to nitrogenous fertilizers. Thirty-five isolates from four rice genotypes were categorized based on acetylene reduction assay on nitrogenase activity, biochemical tests, BIOLOG and 16S rRNA gene sequencing. The bacteria produced 9.36-155.83 nmole C2H4 mg(-1) dry bacteria h(-1) and among them nitrogenase activity of 11 potent isolates was complemented by nifH-sequence analysis. Phylogenetic analysis based on 16S rDNA sequencing divided them into five groups (shared 95-100 % sequence homology with type strains) belonging to five classes-alpha (Ancylobacter, Azorhizobium, Azospirillum, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium, spp.), beta (Burkholderia sp.), gamma (Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas spp.) Proteobacteria, Bacilli (Bacillus, Paenibacillus spp.) and Actinobacteria (Microbacterium sp.). Besides, all bacterial strains possessed the intrinsic PGP traits of like indole (0.44-7.4 µg ml(-1)), ammonia (0.18-6 mmol ml(-1)), nitrite (0.01-3.4 mol ml(-1)), and siderophore (from 0.16-0.57 μmol ml(-1)) production. Inoculation of rice (cv. Swarna) seedlings with selected isolates had a positive impact on plant growth parameters like shoot and root elongation which was correlated with in vitro PGP attributes. The results indicated that the

Effect of Organic and Biological Fertilizers on Growth and Yield of Tomatoes (Lycopersicon esculentum Mill. and Bacterial Colonization

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H. Makarian

2016-02-01

Full Text Available Introduction: In recent decades, excessive use of chemical fertilizers causes environmental problems such as water resource pollution and decrease in soil fertility. Organic matters are excellent sources of plant-available nutrients and their addition to soil could maintain high microbial populations and activities. In crop studies, Prabha et al. (2007 reported that there was excellent plant growth as well as yield in garlic plants that received vermicompost as nutrient in the field (28. Recent studies confirmed that, a number of bacterial species mostly associated with the plant rhizosphere, are found to be beneficial for plant growth, yield and crop quality. Therefore, the objective of this study is to investigate the growth promoting effects of organic and bio-fertilizers on tomato growth and yield. Materials and Methods: A factorial experiment in randomized complete block design with three replications was conducted at the College of Agricultural, University of Shahrood in 2011. Geographically, the site is located in Bastam (36° 25’E, 54° 58’N, 1349 m a.s.l..The climate of this region is semi-arid. Treatments included three levels of organic fertilizers: vermicompost (1300 kgha-1, cow manure (3350 kgha-1, and control, biological fertilizer in four levels (Pseudomonas putyda, Pseudomonas fluorescens, Azotobacter chrococcum and control. The bacterial suspension for each species was applied at a rate of 3 liters per hectare. Metribuzin herbicide (wettable 80% powder was used at a rate of 1000 gr. ha-1. Petopride No. 2' variety of tomato (Lycopersicon esculentum Mill. was used in the present experiment. At the time of harvesting, the plant characteristics namely lengths and diameter of stem, number and weight of fruit, weight of stem and leaf were also registered. Statistical analyses of data were performed with statistical software Mstatc. Significant differences between means refer to the probability level of 0.05 by LSD test. Results

Increasing potassium (K release from K-containing minerals in the presence of insoluble phosphate by bacteria

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Mohammad Reza Sarikhani

2016-03-01

Full Text Available Introduction: Phosphorus and potassium are major essential macronutrients for biological growth and development. Application of soil microorganisms is one approach to enhance crop growth. Some bacteria are efficient in releasing K and solubilizing P from mineral sources but their behavior was not studied more in presence together. Materials and methods: In this study the ability of seven bacterial strains, including Pseudomonas putida P13, P. putida Tabriz, P. fluorescens Tabriz, P. fluorescens Chao, Pantoea agglomerans P5, Azotobacter sp. and Bacillus megaterium JK3 to release mineral K from muscovite and biotite with application of insoluble (Ca3(PO42 or soluble (Na2HPO4 P-sources was investigated. Nutrient Broth was used to prepare an overnight culture of bacteria to inoculate in Aleksandrov medium, which was used to study the dissolution of silicate minerals. It should be mentioned that Aleksandrov medium was used to determine the amount of released P from tricalcium phosphate (TCP while muscovite was added to the medium as a sole source of potassium. Concentration of P was determined spectrophotometrically by ammonium-vanadate-molybdate method and K was determined by flame photometry. Results: The insoluble P-source led to a significantly increased released K into assay medium (66%, and the net release of K from the biotite was significantly enhanced. Among bacterial strains, the highest mean of released K was observed with P. putida P13 which released more K (27% than the control. The amounts of released K from micas in the presence of insoluble and soluble phosphate by P. putida P13 were 8.25 and 4.87 mg/g, respectively. Discussion and conclusion: Application of insoluble phosphate could increase K release from mica minerals. The enhanced releasing of mineral K might be attributed to the release of organic acids from the bacteria, a mechanism which plays a pivotal role in solubilizing phosphate from inorganic source of phosphate.

Pseudomonas tarimensis sp. nov., an endophytic bacteria isolated from Populus euphratica.

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Anwar, Nusratgul; Rozahon, Manziram; Zayadan, Bolatkhan; Mamtimin, Hormathan; Abdurahman, Mehfuzem; Kurban, Marygul; Abdurusul, Mihribangul; Mamtimin, Tursunay; Abdukerim, Muhtar; Rahman, Erkin

2017-11-01

An endophytic bacterium, MA-69 T , was isolated from the storage liquid in the stems of Populuseuphratica trees at the ancient Ugan River in Xinjiang, PR China. Strain MA-69 T was found to be short rod-shaped, Gram-stain-negative, non-spore-forming, aerobic and motile by means of a monopolar flagellum. According to phylogenetic analysis based on 16S rRNA gene sequences, strain MA-69 T was assigned to the genus Pseudomonas with highest 16S rRNA gene sequence similarity of 97.5 % to Pseudomonas azotifigens JCM 12708 T , followed by Pseudomonas matsuisoli JCM 30078 T (97.5 %), Pseudomonas balearica DSM 6083 T (97.1 %), Azotobacter salinestris ATCC 49674 T (96.1 %) and Pseudomonas indica DSM 14015 T (95.9 %). Analysis of strain MA-69 T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the isolate to be distinctly delineated from species of the genus Pseudomonas. The DNA G+C content of strain MA-69 T was 64.1 mol%. DNA-DNA hybridization with Pseudomonas azotifigens JCM 12708 T , Pseudomonas matsuisoli JCM 30078 T and Pseudomonas balearica DSM 6083 T revealed 62.9, 60.1 and 49.0 % relatedness, respectively. The major fatty acids in strain MA-69 T were summed feature 3 (25.7 %), summed feature 8 (24.0 %), C19 : 0cyclo ω8c (19.9 %), C16 : 0 (14.6 %) and C12 : 0 (6.3 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Q-9 was the major quinone in strain MA-69 T . Based on phenotypic, chemotaxonomic and phylogenetic properties, strain MA-69 T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas tarimensis sp. nov. is proposed. The type strain is MA-69 T (=CCTCC AB 2013065 T =KCTC 42447 T ).

Influence of organic and inorganic sources of nutrients on the functional diversity of microbial communities in the vegetable cropping system of the Indo-Gangetic plains.

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Manjunath, Mallappa; Kumar, Upendra; Yadava, Raj Bahadur; Rai, Awadhesh Bahadur; Singh, Bijendra

2018-05-31

The aim of the present study was to assess the effects of different organic and inorganic fertilizers on the functional diversity of soil microbial community under a vegetable production system. The Biolog ® Eco-plate technique and indices, such as average well-colour development (AWCD), McIntosh and Shannon diversity were employed to study the diversity of soil microorganisms. The AWCD, i.e. overall utilization of carbon sources, suggested that different organic treatments had a significant impact on the metabolic activity of soil microorganisms. After 120h, the highest AWCD values were observed in poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (0.63) and farm yard manure (FYM) (10 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (0.61). After 72h, the highest value of the McIntosh diversity index was recorded in poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (3.87), followed by poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 )+biofertilizers (Azotobacter 500 g·ha -1 applied as seed treatment) (3.12). In the case of the Shannon diversity index, the highest values were noticed in organic treatments; however, there was no significant differences between organic and inorganic treatments. Biplot analysis showed a clear differentiation of organic treatments from the inorganic control. The amino acids, phenolics and polymer utilizing microorganisms were dominant in organic treatments. Inorganic control recorded the lowest values of the microbial diversity indices. Through this study, we have identified the best combination of organic nutrients, i.e. poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) for the stimulation of metabolically active soil microbial communities. Copyright © 2018 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

The Effect of Biofertilizers and Winter Cover Crops on Essential Oil Production and Some Agroecological Characteristics of Basil (Ocimum basilicum L.

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M Jahan

2013-04-01

Full Text Available In searching for new strategies of medicinal plant production with high yield but without undesirable compounds or effects, it is important to investigate unconventional alternatives such as application of PGPR and cover crops cultivation. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-10, at Research Farm of Ferdowsi University of Mashhad. Cultivation and no cultivation of cover crops in autumn assigned to the main plots. The sub factor was biofertilizer application with four levels, included 1-Nitroxin (containing Azotobacter spp. and Azospirillum spp., 2-Biophosphorous (Bacillus sp. and Pseudomonas sp., 3-Nitroxin + Biophosphorous and 4-Control. During growing season plants were harvested by three cuts. Results showed that total shoots dry weight, leaves yield and LAI in plants under no cover crop cultivation had a significant advantage. Biofertilizers increased most characteristics e.g. fresh and dry total shoot yield, dry leaves and LAI. The interaction between fertilizer and cover crop was significant, as the highest yield of fresh shoots was observed in mix of nitroxin and biophosphorous with no cover crop, the highest and the lowest of leaf and green area index were obtained in plants treated by nitroxin without cover crop and biophosphorous with cover crop, respectively. Plants harvested in cut 3 had the lowest LAI and other two cuts had no significant difference concerning this trait. The highest and the lowest fresh and dry shoot yield were observed in cut 2 and 1, respectively. The most essential oil yield was in cut 2 and 3 (without significant difference and cut 1 was the lowest. The results showed that the interaction between biofertilizers and no cover crop cultivation was significant, as use of the biofertilizers especially nitroxin and biophosphorous in no cover crop condition enhanced the most characteristics of

THE USE OF gusA REPORTER GENE TO MONITOR THE SURVIVAL OF INTRODUCED BACTERIA IN THE SOIL

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Edi Husen

2013-07-01

Full Text Available An effective marker to monitor the survival of introduced bacteria in the soil is required for further evaluation of their beneficial effects on plant growth. This study tested the use of gusA gene as a marker to trace the fate of three Gram negative bacteria in the root, rhizosphere, and soil. The study was conducted at the laboratory and greenhouse of the National Institute of Molecular Biology and Biotechnology, Philippines from January to December 2001. Isolates TCaR 61 and TCeRe 60, and Azotobacter vinelandii Mac 259 were selected as test bacteria based on their ability to produce indole-3acetic acid and solubilize precipitated phosphate, which may promote plant growth in the field. These bacteria were marked with gusA reporter gene from Escherichia coli strain S17-1(λ-pir containing mTn5SSgusA21. The gusA (β-glucuronidase gene from the donor (E. coli was transferred to each bacterium (recipient through bacterial conjugation in mating procedures using tryptone-yeast agar followed by the selection of the transconjugants (bacteria receiving gusA in tryptone-yeast agar supplemented with double antibiotics and X-GlcA (5bromo-4chloro- 3indoxyl-β-D-glucuronic acid. The antibiotics used were rifampicin and either streptomycin or spectinomycin based on antibiotic profiles of the donor and recipients. The results showed that the insertion of gusA gene into bacterial genomes of the recipient did not impair its phenotypic traits; the growth rates of the transconjugants as well as their ability to produce indole-3acetic acid and solubilize precipitated phosphate in pure culture were similar to their wild types. All transconjugants colonized the roots of hot pepper (Capsicum annuum L. and survived in the rhizosphere and soil until the late of vegetative growth stage. The distinct blue staining of transconjugants as the expression of gusA gene in media containing X-GlcA coupled with their resistance to rifampicin and streptomycin or spectinomycin

Dry matter yield and forage quality traits of oat (Avena sativa L. under integrative use of microbial and synthetic source of nitrogen

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M. Bilal

2017-07-01

Full Text Available The natural microbes are potential contributor to build up soil nitrogen through transformation of molecular nitrogen to plant available forms. Therefore, in the present study, we investigated the contribution of biofertilizer to reduce the synthetic nitrogen application without deteriorating the yield and forage quality. The supplementary nitrogen rates included 0, 40, 80 and 120 kg ha−1 and the seed inoculation was carried out with the mixture of Azospirillum + Azotobacter spp. The experiment was laid out in randomized complete block design with factorial arrangement. The results indicated that organic matter contents and ether extractable fat were negatively associated with both nitrogen and inoculation factors. The inoculation produced 6.58%, 9.58%, 2.51%, 16.94%, 10.26%, 17.59%, 14.02%, 33.81% and 66.18% more No. tillers, plant height, leaf to stem ratio, dry matter yield, mineral matter contents, crude fibre, crude protein, crude protein yield and total digestible crude protein yield, respectively over uninoculation. The interactive effects indicated that inoculation alone without nitrogen application produced 19.16% and 6.87% more dry matter yield and crude protein (%, respectively. The beneficiary effects of biofertilizers on growth and dry matter of oat were more pronounced at intermediate level of inorganic nitrogen which was gradually decreased at higher nitrogen levels. The CP, CPY and DCPY achieved with inoculation alone were statistically equivalent to plots fertilized with 0 and 40 kg N ha−1. It is clear that plots sown with inoculated seeds must be fertilized with 80 kg N to produce higher dry matter and economic returns. However, the highest protein contents in dry matter were recorded with highest fertilization level along with inoculation. By giving due attention to stimulatory effects of bacterial species in the present study, it is therefore, recommended to integrate the use of biofertilizers with supplemental

Identification and Quantification of Cause and Effects in Symbiosis of Corn with Arbuscular Mycorrehiza Fungus using Structural Equation Modeling Approach

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M Jahan

2015-09-01

Full Text Available Considering to necessity and importance of determining mycorrhizal symbiosis level and its effects on crop agroecological characteristics as well as other related factors affecting this relationship, beside, the lack of an assured method for this purpose, the present study designed based on new perspectives and insights for determining cause and effects relations, latent variables using structural equation modeling (SEM approach. A field experiment was conducted during 2 years. A split plots arrangement based on randomized complete block design (RCBD with three replications was used. Treatments consisted four cropping systems (high, medium, and low input conventional as well as ecological system and four inoculations (mycorrhizae fungus: Glomus intraradices, plant growth promoting rhizobacteria (PGPR: (Azospirillum brasilense, Azotobacter paspali, dual inoculation: (fungus plus bacteria, and no-inoculation (control, which were allocated to main plots and sub plots, respectively. At the first step, a confirmatory factor analyzing was conducted resulted to two distinguished factors, and then the variables which had the most loads (weight on one of these two factors were determined. At the second step, considering ecophysiological basis of crops growth and development, in order to continue analyzing, the first factor (including: leaf area index (LAI, root length colonization percent (RLCP, dry matter (DM, stem diameter (D, SPAD readings and the second factor (including: maximum photosynthesis (Amax, specific root length (SRL, canopy temperature (CT, plant height (H, soil respiration rate (SRR, variable chlorophyll fluorescence to maximum chlorophyll fluorescence (Fv/Fm, plant tissue phosphorus content (%P determined resource capture latent construct and resource utilization latent construct, respectively. Correlation coefficients, squared multiple correlation coefficients, covariance matrices, direct and indirect path coefficients were calculated

The gram-negative bacterium Azotobacter chroococcum NCIMB 8003 employs a new glycoside hydrolase family 70 4,6-α-glucanotransferase enzyme (GtfD) to synthesize a reuteran like polymer from maltodextrins and starch

NARCIS (Netherlands)

Gangoiti, Joana; van Leeuwen, Sander S; Vafiadi, Christina; Dijkhuizen, Lubbert

BACKGROUND: Originally the glycoside hydrolase (GH) family 70 only comprised glucansucrases of lactic acid bacteria which synthesize α-glucan polymers from sucrose. Recently we have identified 2 novel subfamilies of GH70 enzymes represented by the Lactobacillus reuteri 121 GtfB and the

Effects of Organic amendments and Biofertilizer Application on some Morphological Traits and Yield of hyssop (Hyssopus officinalis L.

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mohammad taghi darzi

2017-02-01

Full Text Available Introduction: Hyssop (Hyssopus officinalis is a perennial herb which is cultivated in temperate regions of Asia, Europe and America. The essential oil of hyssop is widely used as traditional drug in some of the parts of Asia and Europe to treat respiratory diseases. Hyssop is also used in food, pharmaceutical, flavor and cosmetic industries throughout the world. It is mainly used for antispasmodic, stomachic, antifungal, relax spasm and cough treatment. Applying organic fertilizers and biofertilizers such as compost, vermicompost and nitrogen fixing bacteria contain Azotobacter and Azospirillum has led to a decrease in chemical fertilizers consumption and has provided high quality agricultural products. Several studies have shown that organic and bio-fertilizers application such as vermicompost and nitrogen fixing bacteria can increase essential oil content of medicinal plants of dill, basil and fennel.The main object of this work was to record the best suitable treatment of organic and biological fertilizer to obtain highest yield of Hyssop. Materials and Methods: A field experiment, arranged in a randomized complete blocks design with eight treatments and three replications at research field of the Agriculture Company of Ran, Firouzkuh, Iran during the growing season of 2012. The treatments were (1 20 t/ha compost, (2 12 t/ha vermicompost, (3 biofertilizer [inoculated seeds with Azotobacter and Azospirillum], (4 10 t/ha compost + 6 t/ha vermicompost, (5 20 t/ha compost + biofertilizer, (6 12 t/ha vermicompost + biofertilizer, (7 10 t/ha compost + 6 t/ha vermicompost + biofertilizer and (8 control [without fertilizer application]. Inoculation was carried out by immersing the hyssop seeds in the cells suspension of 108 CFU/ml for 15 min. The required quantities of compost and vermicompost were applied and incorporated to the top 5 cm layer of soil in the experimental beds before planting of hyssop seeds. Each experimental plot was 3 m long by 2

Effect of Biological and Chemical Fertilizers on Oil, Seed Yield and some Agronomic Traits of Safflower under Different Irrigation Regimes

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Hamidreza Fanaei

2017-08-01

Full Text Available Introduction Safflower Carthamus tinctorius L. is a tolerant plant to water deficit due to long roots and capability for high water absorption from soil deeper parts. Safflower can growth successfully in regions with low soil fertility and temperature. Behdani and Mosavifar (2011 reported that drought stress affect on yield by reducing yield components and agronomic traits. Biofertilizer during a biological process chanced the nutrients from unusable to usable form for plants in soils (Aseretal, 2008. Mirzakhani et al. (2008 found that inoculation of seed with free-living bacterium azotobacter and a symbiotic fungus productive mycorrhiza addition to increasing oil and seed cause increasing resistance against two factors of unfavorable environmental and to improve quality of product. In order to study the effect of biological and chemical fertilizers on oil, seed yield and some of agronomic traits of Safflower under irrigation of different regimes an experimental design was conducted. Materials and methods In order to study the effect of biological and chemical fertilizers on oil, seed yield and some of agronomic traits of safflower under irrigation of different regimes an experiment was carried out split plot based on randomized complete block design (RCBD with three replications in experimental farm of payame-Noor university of Zabol during 2012-2013 growing season. Irrigation regime in three levels include: I1 (control irrigation in all growth stages, I2 stop irrigation from sowing to flowering (irrigation in growth stages flowering, and seed filling, I3 irrigation in growth stages rosset, stem elongation, heading and stop irrigation in flowering, and seed filling were as main plots and fertilizer resources in five levels included: F1 non application chemical fertilizer (control, F2 pure application chemical fertilizer (NPK 99, 44 and 123 kg.ha-1 respectively, F3 Nitroxin application (2 L.ha-1 F4 Azotobacter application (2 L.ha-1 and F5

Effects of Organic amendments and Biofertilizer Application on some Morphological Traits and Yield of hyssop (Hyssopus officinalis L.

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mohammad taghi darzi

2017-09-01

Full Text Available Introduction: Hyssop (Hyssopus officinalis is a perennial herb which is cultivated in temperate regions of Asia, Europe and America. The essential oil of hyssop is widely used as traditional drug in some of the parts of Asia and Europe to treat respiratory diseases. Hyssop is also used in food, pharmaceutical, flavor and cosmetic industries throughout the world. It is mainly used for antispasmodic, stomachic, antifungal, relax spasm and cough treatment. Applying organic fertilizers and biofertilizers such as compost, vermicompost and nitrogen fixing bacteria contain Azotobacter and Azospirillum has led to a decrease in chemical fertilizers consumption and has provided high quality agricultural products. Several studies have shown that organic and bio-fertilizers application such as vermicompost and nitrogen fixing bacteria can increase essential oil content of medicinal plants of dill, basil and fennel.The main object of this work was to record the best suitable treatment of organic and biological fertilizer to obtain highest yield of Hyssop. Materials and Methods: A field experiment, arranged in a randomized complete blocks design with eight treatments and three replications at research field of the Agriculture Company of Ran, Firouzkuh, Iran during the growing season of 2012. The treatments were (1 20 t/ha compost, (2 12 t/ha vermicompost, (3 biofertilizer [inoculated seeds with Azotobacter and Azospirillum], (4 10 t/ha compost + 6 t/ha vermicompost, (5 20 t/ha compost + biofertilizer, (6 12 t/ha vermicompost + biofertilizer, (7 10 t/ha compost + 6 t/ha vermicompost + biofertilizer and (8 control [without fertilizer application]. Inoculation was carried out by immersing the hyssop seeds in the cells suspension of 108 CFU/ml for 15 min. The required quantities of compost and vermicompost were applied and incorporated to the top 5 cm layer of soil in the experimental beds before planting of hyssop seeds. Each experimental plot was 3 m long by 2

A New Player in the Biorefineries Field: Phasin PhaP Enhances Tolerance to Solvents and Boosts Ethanol and 1,3-Propanediol Synthesis in Escherichia coli.

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Mezzina, Mariela P; Álvarez, Daniela S; Egoburo, Diego E; Díaz Peña, Rocío; Nikel, Pablo I; Pettinari, M Julia

2017-07-15

The microbial production of biofuels and other added-value chemicals is often limited by the intrinsic toxicity of these compounds. The phasin PhaP from the soil bacterium Azotobacter sp. strain FA8 is a polyhydroxyalkanoate granule-associated protein that protects recombinant Escherichia coli against several kinds of stress. PhaP enhances growth and poly(3-hydroxybutyrate) synthesis in polymer-producing recombinant strains and reduces the formation of inclusion bodies during overproduction of heterologous proteins. In this work, the heterologous expression of this phasin in E. coli was used as a strategy to increase tolerance to several biotechnologically relevant chemicals. PhaP was observed to enhance bacterial fitness in the presence of biofuels, such as ethanol and butanol, and other chemicals, such as 1,3-propanediol. The effect of PhaP was also studied in a groELS mutant strain, in which both GroELS and PhaP were observed to exert a beneficial effect that varied depending on the chemical tested. Lastly, the potential of PhaP and GroEL to enhance the accumulation of ethanol or 1,3-propanediol was analyzed in recombinant E. coli Strains that overexpressed either groEL or phaP had increased growth, reflected in a higher final biomass and product titer than the control strain. Taken together, these results add a novel application to the already multifaceted phasin protein group, suggesting that expression of these proteins or other chaperones can be used to improve the production of biofuels and other chemicals. IMPORTANCE This work has both basic and applied aspects. Our results demonstrate that a phasin with chaperone-like properties can increase bacterial tolerance to several biochemicals, providing further evidence of the diverse properties of these proteins. Additionally, both the PhaP phasin and the well-known chaperone GroEL were used to increase the biosynthesis of the biotechnologically relevant compounds ethanol and 1,3-propanediol in recombinant E

Global transcriptional analysis of nitrogen fixation and ammonium repression in root-associated Pseudomonas stutzeri A1501

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Lu Wei

2010-01-01

Full Text Available Abstract Background Biological nitrogen fixation is highly controlled at the transcriptional level by regulatory networks that respond to the availability of fixed nitrogen. In many diazotrophs, addition of excess ammonium in the growth medium results in immediate repression of nif gene transcription. Although the regulatory cascades that control the transcription of the nif genes in proteobacteria have been well investigated, there are limited data on the kinetics of ammonium-dependent repression of nitrogen fixation. Results Here we report a global transcriptional profiling analysis of nitrogen fixation and ammonium repression in Pseudomonas stutzeri A1501, a root-associated and nitrogen-fixing bacterium. A total of 166 genes, including those coding for the global nitrogen regulation (Ntr and Nif-specific regulatory proteins, were upregulated under nitrogen fixation conditions but rapidly downregulated as early as 10 min after ammonium shock. Among these nitrogen fixation-inducible genes, 95 have orthologs in each of Azoarcus sp. BH72 and Azotobacter vinelandii AvoP. In particular, a 49-kb expression island containing nif and other associated genes was markedly downregulated by ammonium shock. Further functional characterization of pnfA, a new NifA-σ54-dependent gene chromosomally linked to nifHDK, is reported. This gene encodes a protein product with an amino acid sequence similar to that of five hypothetical proteins found only in diazotrophic strains. No noticeable differences in the transcription of nifHDK were detected between the wild type strain and pnfA mutant. However, the mutant strain exhibited a significant decrease in nitrogenase activity under microaerobic conditions and lost its ability to use nitrate as a terminal electron acceptor for the support of nitrogen fixation under anaerobic conditions. Conclusions Based on our results, we conclude that transcriptional regulation of nif gene expression in A1501 is mediated by the nif

Compensation effect of bacterium containing biofertilizer on the growth of Cucumis sativus L. under Al-stress conditions.

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Tóth, Brigitta; Lévai, L; Kovács, B; Varga, Mária Borbélyné; Veres, Szilvia

2013-03-01

Biofertilizers are used to improve soil fertility and plant production in sustainable agriculture. However, their applicability depends on several environmental parameters. The aim of our study was to evaluate the effect of free-living bacteria containing fertilizer on the growth of cucumber (Cucumis sativus L. cvs. Delicates) under aluminium (Al) stress. Different responses to Al stress of cucumber growth parameters were examined in terms of root elongation and physiological traits, such as Spad index (relative chlorophyll value), biomass accumulation of root and shoot, Al uptake and selected element contents (Fe, Mn, Zn, Mg) of leaves and root. The applied bacteria containing biofertilizer contains Azotobacter chroococcum and Bacillus megaterium. The dry weights of cucumber shoots and roots decreased in line with the increasing Al concentration. Due to different Al treatments (10-3 M, 10-4 M) higher Al concentration was observed in the leaves, while the amounts of other elements (Fe, Mn, Zn, Mg) decreased. This high Al content of the leaves decreased below the control value when biofertilizer was applied. In the case of the roots the additional biofertilizer treatments compensated the effect of Al. The relative chlorophyll content was reduced during Al-stress in older plants and the biofertilizer moderated this effect. The root/shoot ratio was decreased in all the Al-treatments in comparison to the control. The living bacteria containing fertilizer also had a modifying effect. The root/shoot ratio increased at the 10-4 M Al2(SO4)2 + biofertilizer and 10-4 M Al(NO3)3 + biofertilizer treatments compared to the control and Al-treatments. According to our results the biofertilizer is an alternative nutrient supply for replacing chemical fertilizers because it enhances dry matter production. Biofertilizer usage is also offered under Al polluted environmental conditions. Although, the nutrient solution is a clean system where we can examine the main processes without

Evaluation of the Effect of Seed Priming and Seedbed on Characteristic of Transplant Sweet Corn (Zea Mays L.

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A Manzari-Tavakkoli

2016-10-01

Full Text Available Introduction Corn (Zea mays L. is one of the main cereals in the tropical and temperate regions of the world. Sweet corn obtained from a genetic mutation on chromosome 4 locus SU conventional maize resulting accumulation of sugars and polysaccharides which are soluble in seed endosperm. Unlike other types of corn, sweet corn endosperm contains a lot of sugar to starch, which is called Amylodextrin and it is soluble in water. Producing healthy and uniform plants is one of the requirements of modern agriculture. Considering the unsuitable climatic condition in Iran (arid and semiarid transplantation is one of the requirements for sustainable agriculture particularly in sweet corn production with high water requirement where transplantation is able to save at least 2-3 times of irrigations. Therefore, producing high quality transplants is an important practice for successful seedling establishment. Hence, the objective of this study was to evaluate the effects of seed priming and substrate types on the characteristics of sweet corn transplants. Materials and Methods This experiment was conducted as factorial based on a completely randomized design with three replications. Treatments were three levels of seeds pretreatment: no priming (p1, hydropriming (p2 and biopriming (p3, and another factor was seedbeds types in seven levels including: vermicompost (b1, perlite (b2, cocopeat(b3, vermicompost+perlite(b4, vermicompost+ cocopeat (b5, perlite+ cocopeat (b6 and vermicompost+ cocopeat +perlite (b7. Biopriming using bioaminopalis biological fertilizer applied on the seeds for 24hours in a solution containing micro-organisms such azotobacter and Pseudomonas. Then the non-primed and the primed seeds were sown in the plastic pots and grown in a greenhouse with average temperature of 22-25° C. Samples were taken three weeks after planting. Results and Discussion Mean emergence time Emergence is shoot elongation and growth leading the shoots out of the

Redox balancing in recombinant strains of Saccharomyces cerevisiae

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Anderlund, M

1998-09-01

In metabolically engineered Saccharomyces cerevisiae expressing Pichia stipitis XYL1 and XYL2 genes, encoding xylose reductase (XR) and xylitol dehydrogenase (XDH), respectively, xylitol is excreted as the major product during anaerobic xylose fermentation and only low yields of ethanol are produced. This has been interpreted as a result of the dual cofactor dependence of XR and the exclusive use of NAD{sup +} by XDH. The excretion of xylitol was completely stopped and the formation of glycerol and acetic acid were reduced in xylose utilising S. cerevisiae strains cultivated in oxygen-limited conditions by expressing lower levels of XR than of XDH. The expression level of XYL1 and XYL2 were controlled by changing the promoters and transcription directions of the genes. A new functional metabolic pathway was established when Thermus thermophilus xylA gene was expressed in S. cerevisiae. The recombinant strain was able to ferment xylose to ethanol when cultivated on a minimal medium containing xylose as only carbon source. In order to create a channeled metabolic transfer in the two first steps of the xylose metabolism, XYL1 and XYL2 were fused in-frame and expressed in S. cerevisiae. When the fusion protein, containing a linker of three amino acids, was co expressed together with native XR and XDH monomers, enzyme complexes consisting of chimeric and native subunits were formed. The total activity of these complexes exhibited 10 and 9 times higher XR and XDH activity, respectively, than the original conjugates, consisting of only chimeric subunits. This strain produced less xylitol and the xylitol yield was lower than with strains only expressing native XR and XDH monomers. In addition, more ethanol and less acetic acid were formed. A new gene encoding the cytoplasmic transhydrogenase from Azotobacter vinelandii was cloned. The enzyme showed high similarity to the family of pyridine nucleotide-disulphide oxidoreductase. To analyse the physiological effect of

Characterization of an M-Cluster-Substituted Nitrogenase VFe Protein.

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Rebelein, Johannes G; Lee, Chi Chung; Newcomb, Megan; Hu, Yilin; Ribbe, Markus W

2018-03-13

The Mo- and V-nitrogenases are two homologous members of the nitrogenase family that are distinguished mainly by the presence of different heterometals (Mo or V) at their respective cofactor sites (M- or V-cluster). However, the V-nitrogenase is ~600-fold more active than its Mo counterpart in reducing CO to hydrocarbons at ambient conditions. Here, we expressed an M-cluster-containing, hybrid V-nitrogenase in Azotobacter vinelandii and compared it to its native, V-cluster-containing counterpart in order to assess the impact of protein scaffold and cofactor species on the differential reactivities of Mo- and V-nitrogenases toward CO. Housed in the VFe protein component of V-nitrogenase, the M-cluster displayed electron paramagnetic resonance (EPR) features similar to those of the V-cluster and demonstrated an ~100-fold increase in hydrocarbon formation activity from CO reduction, suggesting a significant impact of protein environment on the overall CO-reducing activity of nitrogenase. On the other hand, the M-cluster was still ~6-fold less active than the V-cluster in the same protein scaffold, and it retained its inability to form detectable amounts of methane from CO reduction, illustrating a fine-tuning effect of the cofactor properties on this nitrogenase-catalyzed reaction. Together, these results provided important insights into the two major determinants for the enzymatic activity of CO reduction while establishing a useful framework for further elucidation of the essential catalytic elements for the CO reactivity of nitrogenase. IMPORTANCE This is the first report on the in vivo generation and in vitro characterization of an M-cluster-containing V-nitrogenase hybrid. The "normalization" of the protein scaffold to that of the V-nitrogenase permits a direct comparison between the cofactor species of the Mo- and V-nitrogenases (M- and V-clusters) in CO reduction, whereas the discrepancy between the protein scaffolds of the Mo- and V-nitrogenases (MoFe and VFe

[Use of Leersia hexandra (Poaceae) for soil phytoremediation in soils contaminated with fresh and weathered oil].

Science.gov (United States)

Arias-Trinidad, Alfredo; Rivera-Cruz, María del Carmen; Roldán-Garrigós, Antonio; Aceves-Navarro, Lorenzo Armando; Quintero-Lizaola, Roberto; Hernández-Guzmán, Javier

2017-03-01

The oil industry has generated chronic oil spills and their accumulation in wetlands of the state of Tabasco, in Southeastern Mexico. Waterlogging is a factor that limits the use of remediation technologies because of its high cost and low levels of oil degradation. However, Leersia hexandra is a grass that grows in these contaminated areas with weathered oil. The aim of the study was to evaluate the bacteria density, plant biomass production and phytoremediation of L. hexandra in contaminated soil. For this, two experiments in plastic tunnel were performed with fresh (E1) and weathered petroleum (E2) under waterlogging experimental conditions. The E1 was based on eight doses: 6 000, 10 000, 30 000, 60 000, 90 000, 120 000, 150 000 and 180 000 mg.kg-1 dry basis (d. b.) of total petroleum hydrocarbons fresh (TPH-F), and the E2, that evaluated five doses: 14 173, 28 400, 50 598, 75 492 and 112 142 mg. kg-1 d. b. of total petroleum hydrocarbons weathered (TPH-W); a control treatment with 2 607 mg.kg-1 d. b. was used. Each experiment, with eight replicates per treatment, evaluated after three and six months: a) microbial density of total free-living nitrogen-fixing bacteria (NFB) of Azospirillum (AZP) and Azotobacter group (AZT), for viable count in serial plate; b) dry matter production (DMP), quantified gravimetrically as dry weight of L. hexandra; and c) the decontamination percentage of hydrocarbons (PDH) by Soxhlet extraction. In soil with TPH-F, the NFB, AZP y AZT populations were stimulated five times more than the control both at the three and six months; however, concentrations of 150 000 and 180 000 mg.kg-1 d. b. inhibited the bacterial density between 70 and 89 %. Likewise, in soil with TPH-W, the FNB, AZP and AZT inhibitions were 90 %, with the exception of the 14 173 mg.kg-1 d. b. treatment, which stimulated the NFB and AZT in 2 and 0.10 times more than the control, respectively. The DMP was continued at the six months in the experiments, with values of 63

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

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

2014-09-01

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

Response of Sunflower (Helianthus annuus L.) to N-application and Bio fertilization with Assessment of Fertilizer N Recovery by 15N Versus Subtraction Methods

International Nuclear Information System (INIS)

Abdel-Salam, A. A.; Zahra, W.R.; Soliman, S. M.; Galal, Y.G.M.; Moursy, A.A.; Hekal, M.A.

2015-01-01

A factorial field experiment was conducted on sunflower (Helianthus annuus L.) grown on a sand soil (98% sand) supplied the different combinations of 4 N rates of 0, 105, 140 and 175 kg N ha -1 i.e. N 0 , N 1 , N 2 , and N 3 respectively - as (NH 4 ) 2 SO 4 and 4 bio fertilization inoculation (B) of none, Azotobacter chroococcum, Azospirillum brasilense and Bacillus megaterium. i.e. B 0 ,B 1 ,B 2 , and B 3 respectively. Labeled ammonium sulphate with 2% 15 N atom excess was used for 15 N assessment. All plots were supplied with 21 Mg compost +24 kg P +80 kg K ha - '1. Non-treated plants gave 0.534 Mg seeds ha -1 while the treated ones - especially those of N or N + bio fertilizers - gave increases of up to 403% (N 2 B). Main effect response patterns were: N: N 3 >N 2 >N 1 , for B: B 1 ≥B 3 ≥B 2 . Seed oil content in the N 0 B 0 treatment was 222 gkg -1 increased reaching as high as 445 gkg -1 by N 2 B 3 ; with N main effect of N 2 >N 3 >N 1 and B main effect of B 2 >B 3 >B 1 . Seed oil yield was 113 kg ha -1 by N 0 B 0 increased to as high as 1105 kg ha -1 by N 2 B 1 with main effects of N 2 >N 3 >N 1 and B 3 ≥B 2 >B 1 .Uptake of N (in total plant parts of roots + stems + leaves + discs + seeds) increased by N application; averages for non-N were 18.1 kg ha -1 18.5,14.7,17.4 by N 0 B 0 , N 0 B 1 , N 0 B 2 , and N 0 B 3 respectively; increased considerably by up to 667% (N 3 B 3 ) upon N application. Plants recovered a portion of fertilizer N of 19.6 to 40.9% by N 1 B 1 and N 2 B 1 respectively as determined by 15 N technique, but 27.7 to 59.6% respectively as calculated by subtraction of non-N from N treatments. The subtraction estimation considerably exceeded the 15 N determined ones by + 39.5% to as high as + 194.6% indicating a non-real estimation of recovered fertilizer-N in crops. Thus, in studies using non-tracer techniques, estimation of uptake of fertilizer N could be erroneous. The reason in the current study could most certainly be a greater

The Effect of Soil Fertilizers on Yield and Growth Traits of Sorghum (Sorghum bicolor

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R Kamaei

2016-07-01

Full Text Available Introduction Since the use of chemical fertilizers causes environmental pollution and ecological damage, so application of biological fertilizers and selection the effective and compatible species in an special area, could be beneficial for sustainability of agroecosystems there. Nowadays, attention to the interrelation of plant-organism tended to interrelations between plant-organism-organism. Such nutritional relations, have ecological importance and important application in agriculture. The aim of this experiment was to evaluate the effect of chemical, organic and bio fertilizers on sorghum performance. Materials and Methods A field experiment was conducted in a randomized complete block design with three replications. The experimental treatments include three kinds of biofertilizers and their integrations and vermicompost and chemical fertilizer as follow: 1- mycorhhiza arbuscular (G.mosseae + vermicompost 2- mycorhhiza+ Nitroxine® (included bacteria Azospirillum sp. and Azotobacter sp. 3- mycorhhiza arbuscular+ Rhizobium (Rhizobium sp. 4-mycorhhiza arbuscular + Chemical fertilizer NPK 5- mycorhhiza arbuscular 6-control. Mycorhhiza and chemical fertilizer were mixed with soil at the depth of 30 cm before planting. Seeds were inoculated with bio fertilizers and dried at shadow. First irrigation applied immediately after planting. In order to improve seedling emergence second irrigation was performed after 4 days and other irrigation was applied at regular intervals of 10 days. Studied traits were: height and percentage of root colonization, specific root length, seed yield, number of seeds in panicle, thousands seeds weight. To determine the specific root length (root length in a certain volume of soil at the end of the growing season, plants in each plot were sampled. Then the length of root of each sample was determined. Results and Discussion The results showed that although the treatments did not affect the height of stem significantly

The effect of organic, biological and chemical fertilizers on yield, essential oil percentage and some agroecological characteristics of summer savory (Satureja hortensis L. under Mashhad conditions

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E Gholami Sharafkhane

2016-05-01

Full Text Available Introduction Savory (Satureja hortensis L. is an annual herbaceous plant that belongs to the Lamiaceae family. Nowadays, the use of biofertilizers is increased in agriculture and their role in increasing the crops production has been demonstrated in many research works (Vessey, 2003; Chen, 2006; Mahfouz & Sharaf- Eldin, 2007. One of the most important visions is sustainable production of enough food plus paying attention to social, economical and environmental aspects. (Gliessman, 1998 stated that the first step to achieve this goal is optimization and improvement of resources use efficiencies. Considering medicinal importance of savory and its role in the food and pharmaceutical industries (Omidbeigi, 2000, beside the limited nutrient resources and need to increase healthy production through using ecological inputs, this study was designed and conducted aimed to evaluate agroecological characteristics of savory as affected by the application of bio fertilizers, chemical and organic fertilizers under Mashhad conditions. Materials and methods In order to study the effects of organic, biological and chemical fertilizers on quantitative and qualitative characteristics of summer savory, a split-plot design based on RCBD with three replications was conducted during the growing season of 2012 at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran. Different levels of cattle manure (0 and 25 t.ha-1 were assigned to the main plots and different types of bio fertilizers (Nitroxin, containing Azotobacter sp. and Azospirillum sp., Biophosphor, containing phosphate-solubilizing bacteria (Bacillus sp. and Pseudomonas sp., Biosulfur, containing sulfur-solubilizing bacteria (Thiobacillus ssp., combination of Nitroxin+Biophosphor+ Biosulfur, vermicompost (7 t.ha-1, chemical fertilizers (NPK: 60, 60 and 70 kg.ha-1 and control (no fertilizer were used in the sub- plots. Results and discussion According to the results

How Escherichia coli and Saccharomyces cerevisiae build Fe/S proteins.

Science.gov (United States)

Barras, Frédéric; Loiseau, Laurent; Py, Béatrice

2005-01-01

Owing to the versatile electronic properties of iron and sulfur, iron sulfur (Fe/S) clusters are perfectly suited for sensing changes in environmental conditions and regulating protein properties accordingly. Fe/S proteins have been recruited in a wide array of diverse biological processes, including electron transfer chains, metabolic pathways and gene regulatory circuits. Chemistry has revealed the great diversity of Fe/S clusters occurring in proteins. The question now is to understand how iron and sulfur come together to form Fe/S clusters and how these clusters are subsequently inserted into apoproteins. Iron, sulfide and reducing conditions were found to be sufficient for successful maturation of many apoproteins in vitro, opening the possibility that insertion might be a spontaneous event. However, as in many other biological pathways such as protein folding, genetic analyses revealed that Fe/S cluster biogenesis and insertion depend in vivo upon auxiliary proteins. This was brought to light by studies on Azotobacter vinelandii nitrogenase, which, in particular, led to the concept of scaffold proteins, the role of which would be to allow transient assembly of Fe/S cluster. These studies paved the way toward the identification of the ISC and SUF systems, subjects of the present review that allow Fe/S cluster assembly into apoproteins of most organisms. Despite the recent discovery of the SUF and ISC systems, remarkable progress has been made in our understanding of their molecular composition and biochemical mechanisms. Such a rapid increase in our knowledge arose from a convergent interest from researchers engaged in unrelated fields and whose complementary expertise covered most experimental approaches used in biology. Also, the high conservation of ISC and SUF systems throughout a wide array of organisms helped cross-feeding between studies. The ISC system is conserved in eubacteria and most eukaryotes, while the SUF system arises in eubacteria, archaea

Estimation of Corn Yield and Soil Nitrogen via Soil Electrical Conductivity Measurement Treated with Organic, Chemical and Biological Fertilizers

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H. Khalilzade

2016-02-01

Full Text Available Introduction Around the world maize is the second crop with the most cultivated areas and amount of production, so as the most important strategic crop, have a special situation in policies, decision making, resources and inputs allocation. On the other side, negative environmental consequences of intensive consumption of agrochemicals resulted to change view concerning food production. One of the most important visions is sustainable production of enough food plus attention to social, economic and environmental aspects. Many researchers stated that the first step to achieve this goal is optimization and improvement of resources use efficiencies. According to little knowledge on relation between soil electrical conductivity and yield of maize, beside the environmental concerns about nitrogen consumption and need to replace chemical nitrogen by ecological inputs, this study designed and aimed to evaluate agroecological characteristics of corn and some soil characteristics as affected by application of organic and biological fertilizers under field conditions. Materials and Methods In order to probing the possibility of grain yield and soil nitrogen estimation via measurement of soil properties, a field experiment was conducted during growing season 2010 at Research Station, Ferdowsi University of Mashhad, Iran. A randomized complete block design (RCBD with three replications was used. Treatments included: 1- manure (30 ton ha-1, 2-vermicompost (10 ton ha-1, 3- nitroxin (containing Azotobacter sp. and Azospirillum sp., inoculation was done according to Kennedy et al., 4- nitrogen as urea (400 kg ha-1 and 5- control (without fertilizer. Studied traits were soil pH, soil EC, soil respiration rate, N content of soil and maize yield. Soil respiration rate was measured using equation 1: CO2= (V0- V× N×22 Equation 1 In which V0 is the volume of consumed acid for control treatment titration, V is of the volume of consumed acid for sample treatment

Structure of a putative BenF-like porin from Pseudomonas fluorescens Pf-5 at 2.6 A resolution

Energy Technology Data Exchange (ETDEWEB)

Sampathkumar, P.; Swaminathan, S.; Lu, F.; Zhao, X.; Li, Z.; Gilmore, J.; Bain, K.; Rutter, M. E.; Gheyi, T.; Schwinn, D.; Bonanno, J. B.; Pieper, U.; Fajardo, J. E.; Fiser, A.; Almo, S. C.; Chance, M. R.; Baker, D.; Atwell, S.; Thompson, D. A.; Emtage, J. S.; Wasserman, S. R.; Sali, A.; Sauder, J. M.; Burley, S. K.

2010-11-01

Gram-negative bacteria typically overcome poor permeability of outer membranes through general porins like OmpF and OmpC, which form water-filled transmembrane pores permitting diffusion of hydrophilic molecules with no particular selectivity. Many bacteria lacking such general porins use substrate-specific porins to overcome growth-limiting conditions and facilitate selective transport of metabolites. Exclusive reliance on substrate-specific porins yields lower membrane permeability to small molecules (<600 Da) versus that seen for Escherichia coli. In Pseudomonads, transit of most small molecules across the cell membrane is thought to be mediated by substrate-specific channels of the OprD superfamily. This property explains, at least in part, the high incidence of Pseudomonas aeruginosa antibiotic resistance. High-throughput DNA sequencing of the P. aeruginosa chromosome revealed the presence of 19 genes encoding structurally related, substrate-specific porins (with 30-45% pairwise amino acid sequence identity) that mediate transmembrane passage of small, water-soluble compounds. The OprD superfamily encompasses the eponymous OprD subfamily, which includes 9 P. aeruginosa proteins that convey basic amino acids and carbapenem antibiotics, and the OpdK subfamily, which includes 11 P. aeruginosa proteins that convey aromatic acids and other small aromatic compounds. Genome sequencing of other gram-negative bacteria has revealed additional members of the OprD and OpdK subfamilies in various organisms, including other pseudomonads. Among the many bacteria in which OprD superfamily members have been identified are P. putida, P. fluorescens Pf-5, P. syringae, and Azotobacter vinelandii, all of which share closely related genes that encode the so-called BenF-like porins. In P. putida, benF is part of an operon involved in benzoate catabolism regulated by benR. Within this operon, benK, benE, and benF genes have been suggested to contribute toward either influx or efflux

The Effects of Biological Fertilizers, Chemical Fertilizers and Manure Application on Some Qualitative Characteristics of Vicia villosa Roth Forage under Greenhouse Condition

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R Kamaei

2017-03-01

Full Text Available Introduction Fertilizer management plays an important role in successful crop production. The biological fertilizers have been suggested not only to elimination or significant reduction of chemical fertilizer dependency but also increase of soil fertility and improvement of crop yield and quality. Materials and Methods This experiment was conducted in a completely randomized design with three replications at the Research Greenhouse of Ferdowsi University of Mashhad. The experimental treatments included 1- mycorrhizae arbuscular (Glomus mosseae, 2- mycorrhizae arbuscular (Glomus mosseae + vermicompost (M+V, 3- mycorrhizae + nitroxein (included bacteria Azospirillum sp. and Azotobacter sp. (M+N, 4- mycorrhizae arbuscular + Rhizobium (R. legominuzarum (M+R, 5-mycorrhizae arbuscular + NPK Chemical fertilizer (40-40-20 (M+NPK and 6- Control (without fertilizer, C. In bio-fertilizer treatments, seeds were inoculated by mycorrhizae and Rhizobium immediately before planting, according the standard conditions and company recommendations. Chemical fertilizer and vermicompost were applied directly into the soil. The first irrigation was done immediately after planting and an additional irrigation was also done 4 days after planting to improve the seedling emergence. Subsequent irrigations were conducted at 10-days interval. Forage samples were collected at stage of 10% open bud. The samples were oven-dried in 70°C for 48 h and then weighed before being ground to pass through a 1-mm sieve. Both chemical analysis and in vitro digestibility assessments were performed in triplicate. Crud protein (CP, Ash, neutral detergent fiber (NDF and acid detergent fiber (ADF content of forages were measured by standard methods. An in vitro gas production method was conducted to determine the dry matter (DM and organic matter (OM digestibility. All data were subjected to ANOVA using the GLM procedure of SAS (SAS 9.1 and means were compared by using LSD-test at 5

Some Soil Characters and Qualitative Traits of Sunflower Seeds to Different Nutritional Regimes

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F Soleymani

2018-05-01

Full Text Available Introduction To achieve the high economic yield in crops, supplying enough nutrients for plants is important, that much of it, supplied by chemical fertilizers. But excessive use of chemical fertilizers led to environmental problems that these negative effects have caused attention to healthy and ecological sustainable farming systems. One solution to reduce dependence on chemical fertilizers is application of organic and biological products for plant nutrition. Bio-fertilizers are made from one or more species of beneficial microorganisms with preservatives and or their products. In addition, vermicompost is an organic fertilizer and mixed of very active biological bacteria, enzymes, plant residues, manure and earthworm capsule which leads to continued organic matter decomposition and development of microbial and enzymatic activities in soil. Several experiments have shown that the using of biological and organic fertilizers improve growth and quality of products. Materials and Methods To investigate the effect of various nutritional regimes on seed quality characteristics of sunflower (Euroflour cv. and some soil characters, an experiment was carried out as a randomized complete block design with 3 replications in 2015 at the Agricultural Faculty of Bu-Ali Sina University.Treatments included no biological or chemical fertilizer application, 100% of the recommended NP fertilizers (250 kg urea per hectare, 50 kg triple superphosphate per hectare, ½ recomended NP fertilizers, vermicompost (15 ton per hectare mixed with soil, phosphonitrokara (including Bacillus coagulans, Azotobacter chroococcum, Azospirillum lipoferum, 110 ml to inoculate 10 kg seeds, biosulfur (including Thiobacillus,mix 6 kg of fertilizer with 300 kg sulphur for 1 hectare, vermicompost+ phosphonitrokara, vermicompost+ biosulfur, vermicompost+½ NP fertilizers, phosphonitrokara+½ NP fertilizers, biosulfur+½ NP fertilizers, vermicompost+ phosphonitrokara+½ NP fertilizers

Effect of Seed Priming, Sowing methods and Bio-fertilizers on Yield and Yield Components of Seedy Watermelon (Citrullus Lanatus

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M Zarandi

2018-02-01

Full Text Available Introduction Watermelon (Citrullus Lanatus is one of the most important fresh fruits in Iran particularly during summer. After China, in terms of production and cultivation area, Iran placed second in the world. Research conducted in different regions (especially in arid and semi-arid regions, like Iran indicated that poor germination and establishment of seedlings in the field causes low yield, particularly in vegetables. Seed priming, (to increase the percentage and rate of germination and transplanting to increase plant establishment and use of bio-fertilizers to increase food availability during the growing season are inevitable to transfer to ecological agriculture. The purpose of this research was to evaluate the effect of seeds osmopriming, transplanting and bio-fertilizers on watermelon grain yield. Materials and Methods This experiment was conducted at split plot based on complete block design with three replications in the Laboratory, Greenhouse and the Farm of the Faculty of Agriculture, Ferdowsi University of Mashhad in 2013. First factor was seed priming in two levels (unprimed and primed, the second factor was transplanting in two levels (direct sowing and transplantation and the third factor was bio-fertilizers containing pseudomonas and Azotobacter in two levels (non bio-fertilizers and bio-fertilizers. Leaf area index (LAI, number of fruits per plant, number of seeds per fruit, 1000 seed weight, grain yield and total dry matter were determined. Results and Discussion Transplants produced using osmoprimed seeds that had been sprayed with bio-fertilizers on the field (T2P2K2 had higher LAI than the other treatments (Table 3. Bio-fertilizers in both transplanting and direct sowing produced more LAI, but osmopriming of seeds with PEG 6000 had little impact on LAI (Table 3. LAI is one of the growth parameters which had a great effect to achieve maximum yield that needs to be at higher level before flowering. Izadkhah et al. (2010 and

Effect of simultaneous application of mycorrhiza with compost, vermicompost and sulfural geranole on some quantitative and qualitative characteristics of sesame (Sesamum indicum L. in a low input cropping system

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P rezvani moghaddam

2016-03-01

quantitative and qualitative characteristics of plant, moreover, decreased environment risks of chemical inputs and ensure sustainability of production in long time by this approach. Acknowledgments We wish to thank Vice President for Research and Technology, Ferdowsi University of Mashhad, Iran for the financial support of the project. Keywords: Ecological inputs, Glomus mosseae, Health of food, Medicinal crops References Hawkes, C.V., Hartley, I.P., Ineson, P., and Fitter, A.H. 2008. Soil temperature affects carbon allocation within arbuscular mycorrhizal networks and carbon transport from plant to fungus. Global Change Biology 14: 1181-1190. Motta, S.R., and Maggiore, T. 2013. Evaluation of nitrogen management in maize cultivation grown on soil amended with sewage sludge and urea. European Journal of Agronomy 45: 59-67. Raja Sekar, K., and Karmegan, N. 2010. Earthworm casts as an alternate carrier material for biofertilizers: Assessment of endurance and viability of Azotobacter chroococcum, Bacillus megaterium and Rhizobium leguminosarum. Scientia Horticulturae 124: 286-289.

The Effects of Soil Amendments and Bio-fertilizers Inoculation on Morphological Characteristics and Yield of Echium amoenum

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M.B. Amiri

2017-10-01

one of the most important medicinal plants in Iranian traditional medicine. Petals of Iranian oxtongue have been advocated for a variety of effects such as demulcent, anti-inflammatory and analgesic, especially for common cold, anxiolytic, sedative and other psychiatric symptoms including obsession in folk medicine of Iran. Despite many research on the effects of organic acids and bio-fertilizers on different crops, there is scarce information on the effects of these factors for many medicinal plants. Therefore, in this study effect of organic acids and bio-fertilizers on morphological characteristics and yield of Echium amoenum in a low input cropping system was studied. Materials and methods: In order to evaluate the effects of soil amendments and different bio-fertilizers on morphological characteristics and seed yield of Echium amoenum, an experiment was conducted based on randomized complete block design with three replications during 2011-2013 growing seasons, at the Research Farm of Ferdowsi University of Mashhad, Iran. Treatments were eight different types of soil amendments and bio-fertilizers concluding: 1 Humic acid, 2 Fulvic acid, 3 Nitroxin® (Azotobacter spp. and Azospirillum spp., 4 Biophosphorous® (Bacillus sp. and Pseudomonas sp., 5 Biosulfur® (Thiobacillus spp., 6 Mycorrhiza (Glomus mosseae, 7 Mycorrhiza (Glomus intraradices, and 8 no fertilizer as control. Result and Discussion: The results showed that mycorrhiza species increased flower yield compared with control, as the flower yield in treatments of G. mosseae and G. intraradices were 24 and 11 percent more than control, respectively. Soil amendments and different bio-fertilizers increased the number of flower cycle per plant compared with control. Although the effect of biophosphorous® was more pronounced, as the number of flower cycle per plant increased from 342 to 1322 cycles in control and biophosphorous® , respectively. Humic acid treatment increased seed yield, biological yield, seed

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

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R. Seyed Sharifi

2016-02-01

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

Effects of Different Amounts of Nitrogen and Azotobarvar on Growth Characteristics and Yield of Chickpea (Cicer arietinum L.

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ghobad mohammadpoor

2017-09-01

Full Text Available Introduction One of the most important agricultural efforts is to minimize the use of chemicals nitrogen fertilizers and to replace it with biological nitrogen fertilizers to produce healthy productions. In dry conditions the use of industrial nitrogen fertilizers depends on the amount of rainfall and consumed cautiously. Low consumption of nitrogen sources reduce crop growth and yield and higher than optimum applications of chemical Nitrogen sources can cause many environmental disorders. This is while Azotobacter as a soil bacteria also fixes nitrogen, produce vitamins, growth hormones and antibiotics and also increases the photosynthesis, plant growth and grain yield and reduces the need to application of chemical Nitrogen. Materials and Methods In order to study the effect of biological and industrial nitrogen fertilizers on growth, yield and yield components of chickpea (Bivanij variety, an experiment was conducted with split plot arrangement based on randomized complete block design (RCBD with four replications under rainfed conditions in the Telesm village, Dalahoo, Kermanshah, during 2013 agricultural season. Climate of the region is temperate and semi-arid with 535.6 mm of rainfall. Soil texture is clay - loam with 0.02 percent of nitrogen. Basic amount of Nitrogen fertilizer was considered 30 Kg.ha-1 Urea and four levels of chemical nitrogen fertilizers including: %50 of base fertilizer, %100 of base fertilizer, %150 of base fertilizer and no fertilizer (control were assumed as main plot factors. Similarly, the basic amount of Azotobarvar bio-fertilizer was considered as 100 g.ha-1 and four levels of it including %50 of base fertilizer, %100 of base fertilizer, %150 of base fertilizer and no bio-fertilizer (control were assumed as sub plot factors. Bio-fertilizers are inoculated to seeds and planting was done manually on 19 March 2013. Density was considered 40 plants per square meter with 25 cm intervals between rows and 10 cm on the

Evaluation of Two Mycorrhiza Species and Nitroxin on Yield and Yield Components of Garlic (Allium sativum L. in an Ecological Agroecosystem

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P Rezvani Moghaddam

2016-02-01

biofertilizers on different crops, information on the effects of these factors for many medicinal plants such as garlic is scarce; therefore, in this study the effects of mycorrhiza and biofertilizers on quantitative characteristics of garlic in a low input cropping system were studied. Materials and Methods In order to study the effects of two mycorrhiza species and nitroxin on yield and yield components of garlic (Allium sativum L., an experiment was conducted in a factorial arrangement based on a randomized completed block design with three replications in the growing seasons of 2010 at the experimental farm of College of Agriculture, Ferdowsi University of Mashhad, Iran. The experimental factors were all combination of two mycorrhiza species (Glomus mosseae, Glomus intraradices and control and also inoculation with and without nitroxin (include Azotobacter sp. and Azospirillum sp. as a biofertilizer. Results and Discussion The results showed that both two mycorrhiza species had superior effects on most of the study traits compared with control. Bulb weight per plant was significantly affected by mycorrhiza species. Glomus mosseae، and Glomus intraradices increased bulb weight per plant by 48 and 29 percent compared with control, respectively. Nitroxin had a significant effect on length and diameter of bulbs. Length and diameter of bulbs were increased by 13 and 8 percent using nitroxin compared with control, respectively. Interactive effects of mycorrhiza and nitroxin on all study traits also were significant. Interactive effects of study treatments showed that Glomus mosseae had better effect on most of study traits at with and without nitroxin treatments. On the other hand, nitroxin had synergistic effect on mycorrhiza treatments compared when these treatments were used without nitroxin. Highest (4306 kg ha-1 and lowest (1665 kg ha-1 economic yield (bulb yield were obtained from Glomus mosseae + Nitroxin and control (without mycorhiza and nitroxin, respectively. In

The Effect of Different Fertilizer Management on Yield and Yield Components of Black Seed (Nigella sativa L.

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P rezvani moghaddam

2017-08-01

Full Text Available Introduction Given the importance of nitrogen for improving the quantitative and qualitative yield of crops (Rodrigues et al., 2006 and the need for application of chemical fertilizers in intensive agriculture to get the maximum production, nitrogen supply in adequate amounts by ecologically avowed resources is known as one of the main challenges during transition from conventional to organic farming (Rodrigues et al., 2006. Considering the sustainable nitrogen management, reconstruction and rehabilitation of agroecosystems depends on reduction the nitrogen losses due to leaching, soil erosion and volatilization (Kizilkaya, 2008. For this purpose, the use of eco-friendly bio based fertilizers that are derived from natural origin, known as effective and enforceable approaches. In this regards, the proper use of manure and free-living aerobic bacteria of soils, such as Azotobacter and Azospirillum as well as mycorrhizal inoculation which can be used as a biological fertilizers, can particularly be considered (Kizilkaya, 2008. With regard to all mentioned above, the current study was aimed to evaluate the effects of biological, organic and inorganic resources of nitrogen on yield and yield components of black seed (Nigella sativa L.. Materials and methods The field experiment was conducted at Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in years of 2009-2010. Experimental site was located in a semi-arid region, Khorasan Province, Northeast of Iran. The soil texture was silty loam, pH 8.36, electrical conductivity 3.72 dS.m-1, total N 0.095% and 0.195% organic carbon. The available P and K contents were 5.76 and 0.378 ppm, respectively. Experimental design was arranged by using a completely randomized block design with three replications. Experimental treatments included chemical fertilizer (urea, urea + nitroxin, urea + mycorrhizae, urea + nitroxin + mycorrhizae, urea + biosulfur, manure, manure + nitroxin, manure + mycorrhizae

Effects of Vermicompst and Nitroxin Biofertilizer on Quantity and Quality of Essential Oil of Dragonhead (Dracocephalum moldavica L.

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hesam sajadi niaki

2016-11-01

Full Text Available Introduction Dragonhead (Dracocephalum moldavica L. is an annual herbaceous aromatic plant and belongs to Lamiaceae family. It is native to south of Siberia and Himalayan hillsides. The essential oil content shows great variation due to plant origin. The main constituents of dragonhead essential oil have been reported as geranial, geranyl acetate, neral and geraniol. Using organic manures and biofertilizers such as vermicompost and nitrogen fixing bacteria contain azotobacter and azospirillum has led to a decrease in the application of chemical fertilizers and has provided high quality agricultural products. Several studies have shown that organic and bio-fertilizers application such as vermicompost and Nitroxin can increase quantity and quality of essential oil of medicinal plants of dragonhead, anise and thyme (Darzi et al., 2013; Mafakheri et al., 2012; Mohammadpour Vashvaei et al., 2015. Therefore, the main objective of the present field experiment was to investigate the effects of vermicompst and Nitroxin biofertilizer on quantity and quality of essential oil of dragonhead. Materials and methods An experiment was conducted as afactorial experiment in the base of randomized complete blocks design with six treatments and three replications at research field of Agriculture Company of Ran in Firouzkuh of Iran in 2013. The factors were Vermicompost in three levels (0, 5 and 10 t.ha-1 and Nitroxinbiofertilizer (inoculated seeds and non-inoculated. Inoculation was carried out by immersing the dragonhead seeds in the cells suspension of 108 CFU/ml for 15 min. The required quantities of vermicompost were applied and incorporated to the top 5 cm layer of soil in the experimental beds before planting of dragonhead seeds. Each experimental plot was 3 m long and 2.28 m wide with the spacing of 10 cm between the plants and 38 cm between the rows. There was a space of one meter between the plots and 2 meters between replications. In this study

Introduction of Endophytic Pseudomonas rhodesiae and Acinetobacter sp. Effective on Seed Germination and Cucumber Growth Factors Improvement

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Farkhondeh Amini

2017-03-01

Full Text Available Introduction: Some bacteria are capable of entering the plant as endophytes that do not cause harm and could establish a mutualistic association with host plants. Endophytic bacteria are bacteria that live in plant tissues without doing substantive harm. They enter plant tissue primarily through different plant zones. Both Gram-positive and Gram-negative bacteria have been isolated from several tissue types in several plant species. In addition, several different bacterial species have been isolated from a single plant. Variation in endophytic bacteria populations referred to the time of sampling, type of plant tissue, age and environment conditions, as well. In general endophytic bacteria occur at lower population densities than rhizospheric bacteria or bacterial pathogens. Endophytic populations, like rhizospheric populations, are conditioned by biotic and abiotic factors, but endophytic bacteria could be better protected from biotic and abiotic stresses than rhizospheric bacteria. It is clear that the interaction between plants and some endophytic bacteria is associated with beneficial effects such as plant growth promotion and biocontrol potential against plant pathogens. These types of bacteria are often capable of eliciting significant physiological changes that modulate the growth and development of the plant. Most of the time, these beneficial effects of endophytes are greater than those of many rhizosphere-colonizing bacteria. Endophytic bacteria affect bacterial growth by numerous mechanisms directly or indirectly. Some genus of bacteria such as Azosprillium, Enterobacter, Azotobacter and Pseudomonas produces plant growth regulators which lead to plant growth improvement. Microorganism profit from plants due to the enhanced availability of nutrients, whereas plants can receive benefits from bacterial associates by growth enhancement or stress reduction. Therefore, mutualistic interactions between host plants and associated

The effect of biological fertilizers on yield, yield components and seed oil contents of three cultivars of canola (Brassica napus L.

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A Koocheki

2016-05-01

achieve this goal is optimization and improvement of resources use efficiencies. Considering medicinal importance of savory and its role in the food and pharmaceutical industries (Omidbeigi, 2000, beside the limited nutrient resources and need to increase healthy production through using ecological inputs, this study was designed and conducted aimed to evaluate agroecological characteristics of savory as affected by the application of bio fertilizers, chemical and organic fertilizers under Mashhad conditions. Materials and methods In order to study the effects of organic, biological and chemical fertilizers on quantitative and qualitative characteristics of summer savory, a split-plot design based on RCBD with three replications was conducted during the growing season of 2012 at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran. Different levels of cattle manure (0 and 25 t.ha-1 were assigned to the main plots and different types of bio fertilizers (Nitroxin, containing Azotobacter sp. and Azospirillum sp., Biophosphor, containing phosphate-solubilizing bacteria (Bacillus sp. and Pseudomonas sp., Biosulfur, containing sulfur-solubilizing bacteria (Thiobacillus ssp., combination of Nitroxin+Biophosphor+ Biosulfur, vermicompost (7 t.ha-1, chemical fertilizers (NPK: 60, 60 and 70 kg.ha-1 and control (no fertilizer were used in the sub- plots. Results and discussion According to the results, all studied characteristics including plant height, lateral branches, flowering shoot yield, stem yield, percentage of essential oil and dry matter yield were affected positively by cattle manure. The highest plant height and number of lateral branches resulted from vermicompost and combination of Nitroxin+Biophosphor+Biosulfur, respectively. Biosulfur fertilizer produced the highest dry matter yield, flowering shoot yield and stem yield. Percentage of essential oil was also significantly affected by fertilizer treatments as the most