| insertion of heterometals into the nifen-associated iron-molybdenum cofactor precursor. | the cofactors of mo-, v-, fe-dependent nitrogenases are believed to be highly homologous in structure despite the different types of heterometals (mo, v, and fe) they contain. previously, a precursor form of the femo cofactor (femoco) was captured on nifen, a scaffold protein for femoco biosynthesis. this all-fe precursor closely resembles the fe/s core structure of the femoco and, therefore, could reasonably serve as a precursor for all nitrogenase cofactors. here, we report the heterologous in ... | 2010 | 19967421 |
| insertion of heterometals into the nifen-associated iron-molybdenum cofactor precursor. | the cofactors of mo-, v-, fe-dependent nitrogenases are believed to be highly homologous in structure despite the different types of heterometals (mo, v, and fe) they contain. previously, a precursor form of the femo cofactor (femoco) was captured on nifen, a scaffold protein for femoco biosynthesis. this all-fe precursor closely resembles the fe/s core structure of the femoco and, therefore, could reasonably serve as a precursor for all nitrogenase cofactors. here, we report the heterologous in ... | 2010 | 19967421 |
| combined effects of co2 and light on the n2-fixing cyanobacterium trichodesmium ims101: a mechanistic view. | the marine diazotrophic cyanobacterium trichodesmium responds to elevated atmospheric co(2) partial pressure (pco(2)) with higher n(2) fixation and growth rates. to unveil the underlying mechanisms, we examined the combined influence of pco(2) (150 and 900 microatm) and light (50 and 200 micromol photons m(-2) s(-1)) on trichodesmium ims101. we expand on a complementary study that demonstrated that while elevated pco(2) enhanced n(2) fixation and growth, oxygen evolution and carbon fixation incr ... | 2010 | 20625002 |
| hydrogen cycling by the unicellular marine diazotroph crocosphaera watsonii strain wh8501. | the hydrogen (h₂) cycle associated with the dinitrogen (n₂) fixation process was studied in laboratory cultures of the marine cyanobacterium crocosphaera watsonii. the rates of h₂ production and acetylene (c₂h₂) reduction were continuously measured over the diel cycle with simultaneous measurements of fast repetition rate fluorometry and dissolved oxygen. the maximum rate of h₂ production was coincident with the maximum rates of c₂h₂ reduction. theoretical stoichiometry for n₂ fixation predicts ... | 2010 | 20709832 |
| nitrogen fixation and hydrogen metabolism in cyanobacteria. | this review summarizes recent aspects of (di)nitrogen fixation and (di)hydrogen metabolism, with emphasis on cyanobacteria. these organisms possess several types of the enzyme complexes catalyzing n(2) fixation and/or h(2) formation or oxidation, namely, two mo nitrogenases, a v nitrogenase, and two hydrogenases. the two cyanobacterial ni hydrogenases are differentiated as either uptake or bidirectional hydrogenases. the different forms of both the nitrogenases and hydrogenases are encoded by di ... | 2010 | 21119016 |
| unraveling the molecular mechanisms of nitrogenase conformational protection against oxygen in diazotrophic bacteria. | g. diazotrophicus and a. vinelandii are aerobic nitrogen-fixing bacteria. although oxygen is essential for the survival of these organisms, it irreversibly inhibits nitrogenase, the complex responsible for nitrogen fixation. both microorganisms deal with this paradox through compensatory mechanisms. in a. vinelandii a conformational protection mechanism occurs through the interaction between the nitrogenase complex and the fesii protein. previous studies suggested the existence of a similar syst ... | 2010 | 21210973 |
| purification and characterization of a bifunctional alginate lyase from pseudoalteromonas sp. sm0524. | an alginate lyase-producing bacterial strain, pseudoalteromonas sp. sm0524, was screened from marine rotten kelp. in an optimized condition, the production of alginate lyase from pseudoalteromonas sp. sm0524 reached 62.6 u/ml, suggesting that strain sm0524 is a good producer of alginate lyases. the bifunctional alginate lyase aly-sj02 secreted by strain sm0524 was purified. aly-sj02 had an apparent molecular mass of 32 kda. the optimal temperature and ph of aly-sj02 toward sodium alginate was 50 ... | 2011 | 21339950 |
| characters of homogentisate oxygenase gene mutation and high clonality of the natural pigment-producing vibrio cholerae strains. | abstract: background: some microorganisms can produce pigments such as melanin, which has been associated with virulence in the host and with a survival advantage in the environment. in vibrio cholerae, studies have shown that pigment-producing mutants are more virulent than the parental strain in terms of increased uv resistance, production of major virulence factors, and colonization. to date, almost all of the pigmented v. cholerae strains investigated have been induced by chemicals, culture ... | 2011 | 21592381 |
| transcript analysis of the extended hyp-operon in the cyanobacteria nostoc sp. strain pcc 7120 and nostoc punctiforme atcc 29133. | | 2011 | 21672234 |
| defining the pseudomonas genus: where do we draw the line with azotobacter? | the genus pseudomonas has gone through many taxonomic revisions over the past 100 years, going from a very large and diverse group of bacteria to a smaller, more refined and ordered list having specific properties. the relationship of the pseudomonas genus to azotobacter vinelandii is examined using three genomic sequence-based methods. first, using 16s rrna trees, it is shown that a. vinelandii groups within the pseudomonas close to pseudomonas aeruginosa. genomes from other related organisms ( ... | 2011 | 21811795 |
| defining the pseudomonas genus: where do we draw the line with azotobacter? | the genus pseudomonas has gone through many taxonomic revisions over the past 100 years, going from a very large and diverse group of bacteria to a smaller, more refined and ordered list having specific properties. the relationship of the pseudomonas genus to azotobacter vinelandii is examined using three genomic sequence-based methods. first, using 16s rrna trees, it is shown that a. vinelandii groups within the pseudomonas close to pseudomonas aeruginosa. genomes from other related organisms ( ... | 2011 | 21811795 |
| Study of enzymatic properties of phenol oxidase from nitrogen-fixing Azotobacter chroococcum. | ABSTRACT: Azotobacter chroococcum is a widespread free-living soil bacterium within the genus of Azotobacter known for assimilation of atmospheric nitrogen and subsequent conversion into nitrogenous compounds, which henceforth enrich the nitrogen content of soils. A. chroococcum SBUG 1484, isolated from composted earth, exhibits phenol oxidase (PO) activity when growing under nitrogen-fixing conditions. In the present study we provide incipient analysis of the crude PO activity expressed by A. c ... | 2011 | 21906365 |
| interactive and single effects of ectomycorrhiza formation and bacillus cereus on metallothionein mt1 expression and phytoextraction of cd and zn by willows. | single and joint ectomycorrhizal (+ hebeloma mesophaeum) and bacterial (+ bacillus cereus) inoculations of willows (salix viminalis) were investigated for their potential and mode of action in the promotion of cadmium (cd) and zinc (zn) phytoextraction. dual fungal and bacterial inoculations promoted the biomass production of willows in contaminated soil. single inoculations either had no effect on the plant growth or inhibited it. all inoculated willows showed increased concentrations of nutrit ... | 2011 | 22389535 |
| interactive and single effects of ectomycorrhiza formation and bacillus cereus on metallothionein mt1 expression and phytoextraction of cd and zn by willows. | single and joint ectomycorrhizal (+ hebeloma mesophaeum) and bacterial (+ bacillus cereus) inoculations of willows (salix viminalis) were investigated for their potential and mode of action in the promotion of cadmium (cd) and zinc (zn) phytoextraction. dual fungal and bacterial inoculations promoted the biomass production of willows in contaminated soil. single inoculations either had no effect on the plant growth or inhibited it. all inoculated willows showed increased concentrations of nutrit ... | 2011 | 22389535 |
| production of indole acetic acid by pseudomonas sp.: effect of coinoculation with mesorhizobium sp. cicer on nodulation and plant growth of chickpea (cicer arietinum). | pseudomonas isolates obtained from the rhizosphere of chickpea (cicer arietinum l.) and green gram (vigna radiata) were found to produce significant amount of indole acetic acid (iaa) when grown in a lb medium broth supplemented with l-tryptophan. seed bacterization of chickpea cultivar c235 with different pseudomonas isolates showed stunting effect on the development of root and shoot at 5 and 10 days of seedling growth except the strains mps79 and mps90 that showed stimulation of root growth, ... | 2011 | 23572992 |
| the novel regulatory ncrna, nfis, optimizes nitrogen fixation via base pairing with the nitrogenase gene nifk mrna in pseudomonas stutzeri a1501. | unlike most pseudomonas, the root-associated bacterium pseudomonas stutzeri a1501 fixes nitrogen after the horizontal acquisition of a nitrogen-fixing (nif) island. a genome-wide search for small noncoding rnas (ncrnas) in p. stutzeri a1501 identified the novel p. stutzeri-specific ncrna nfis in the core genome, whose synthesis was significantly induced under nitrogen fixation or sorbitol stress conditions. the expression of nfis was rna chaperone hfq-dependent and activated by the sigma factor ... | 2016 | 27407147 |
| metaproteomics reveals major microbial players and their biodegradation functions in a large-scale aerobic composting plant. | composting is an appropriate management alternative for municipal solid waste; however, our knowledge about the microbial regulation of this process is still scare. we employed metaproteomics to elucidate the main biodegradation pathways in municipal solid waste composting system across the main phases in a large-scale composting plant. the investigation of microbial succession revealed that bacillales, actinobacteria and saccharomyces increased significantly with respect to abundance in compost ... | 2015 | 25989417 |
| conserved amino acid sequence features in the alpha subunits of mofe, vfe, and fefe nitrogenases. | this study examines the structural features and phylogeny of the alpha subunits of 69 full-length nifd (mofe subunit), vnfd (vfe subunit), and anfd (fefe subunit) sequences. | 2009 | 19578539 |
| isolation of nitrogen-fixing bacteria containing molybdenum-independent nitrogenases from natural environments. | seven diazotrophs that grow well under mo-deficient, n(2)-fixing conditions were isolated from a variety of environments. these isolates fall in the gamma subdivision of the class proteobacteria and have genes that encode the mo nitrogenase (nitrogenase 1) and the v nitrogenase (nitrogenase 2). four of the isolates also harbor genes that encode the iron-only nitrogenase (nitrogenase 3). | 1999 | 10473439 |
| molecular characterization of diazotrophic and denitrifying bacteria associated with mangrove roots. | an analysis of the molecular diversity of n(2) fixers and denitrifiers associated with mangrove roots was performed using terminal restriction length polymorphism (t-rflp) of nifh (n(2) fixation) and nirs and nirk (denitrification), and the compositions and structures of these communities among three sites were compared. the number of operational taxonomic units (otu) for nifh was higher than that for nirk or nirs at all three sites. site 3, which had the highest organic matter and sand content ... | 2007 | 17827324 |
| plant growth-promoting bacteria: mechanisms and applications. | the worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. it is therefore essential that agricultural productivity be significantly increased within the next few decades. to this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. this includes both the increasing use of transgenic plants and plant ... | 2012 | 24278762 |
| bio-preparates support the productivity of potato plants grown under desert farming conditions of north sinai: five years of field trials. | organic agriculture as well as good agricultural practices (gaps) intrigues the concern of both consumers and producers of agricultural commodities. bio-preparates of various rhizospheric microorganisms (rmos) are potential sources of biological inputs supporting plant nutrition and health. the response of open-field potatoes to the application of rmo bio-preparates, the biofertilizer "biofertile" and the bioagent "biocontrol", were experimented over 5 successive years under n-hunger of north si ... | 2013 | 25685470 |
| bio-preparates support the productivity of potato plants grown under desert farming conditions of north sinai: five years of field trials. | organic agriculture as well as good agricultural practices (gaps) intrigues the concern of both consumers and producers of agricultural commodities. bio-preparates of various rhizospheric microorganisms (rmos) are potential sources of biological inputs supporting plant nutrition and health. the response of open-field potatoes to the application of rmo bio-preparates, the biofertilizer "biofertile" and the bioagent "biocontrol", were experimented over 5 successive years under n-hunger of north si ... | 2013 | 25685470 |
| functional soil microbiome: belowground solutions to an aboveground problem. | there is considerable evidence in the literature that beneficial rhizospheric microbes can alter plant morphology, enhance plant growth, and increase mineral content. of late, there is a surge to understand the impact of the microbiome on plant health. recent research shows the utilization of novel sequencing techniques to identify the microbiome in model systems such as arabidopsis (arabidopsis thaliana) and maize (zea mays). however, it is not known how the community of microbes identified may ... | 2014 | 25059708 |
| maize growth promotion by inoculation with azospirillum brasilense and metabolites of rhizobium tropici enriched on lipo-chitooligosaccharides (lcos). | there is an increasing interest in the development and use of inoculants carrying plant growth-promoting bacteria (pgpb) in crops of agronomic interest. the great majority of the inoculants commercialized worldwide contain rhizobia for legume crops, but the use of pgpb as azospirillum spp. for non-legume is expanding, as well as of inoculants combining microorganisms and microbial metabolites. in this study we evaluated the effects of inoculants containing azospirillum brasilense with or without ... | 2015 | 26567001 |
| composition of soil microbiome along elevation gradients in southwestern highlands of saudi arabia. | saudi arabia is mostly barren except the southwestern highlands that are susceptible to environmental changes, a hotspot for biodiversity, but poorly studied for microbial diversity and composition. in this study, 454-pyrosequencing of 16s rrna gene hypervariable region v6 was used to analyze soil bacterial community along elevation gradients of the southwestern highlands. | 2015 | 25888310 |
| bacillus subtilis early colonization of arabidopsis thaliana roots involves multiple chemotaxis receptors. | colonization of plant roots by bacillus subtilis is mutually beneficial to plants and bacteria. plants can secrete up to 30% of their fixed carbon via root exudates, thereby feeding the bacteria, and in return the associated b. subtilis bacteria provide the plant with many growth-promoting traits. formation of a biofilm on the root by matrix-producing b. subtilis is a well-established requirement for long-term colonization. however, we observed that cells start forming a biofilm only several hou ... | 2016 | 27899502 |
| fingerprinting diazotroph communities in the chesapeake bay by using a dna macroarray. | investigations of the distribution and diversity of nitrogen-fixing microorganisms in natural environments have often relied on pcr amplification and sequence analysis of a portion of one of the key enzymes in nitrogen fixation, dinitrogenase reductase, encoded by nifh. recent work has suggested that dna macroarrays provide semiquantitative fingerprints of diversity within mixtures of nifh amplicons (g. f. steward, b. d. jenkins, b. b. ward, and j. p. zehr, appl. environ. microbiol. 70:1455-1465 ... | 2004 | 15006803 |
| isolation, screening, and molecular characterization of plant growth promoting rhizobacteria isolates of azotobacter and trichoderma and their beneficial activities. | the present study was conducted for isolation, screening, and identification of azotobacter and trichoderma from different soil samples. | 2015 | 26283830 |
| azotobacter genomes: the genome of azotobacter chroococcum ncimb 8003 (atcc 4412). | the genome of the soil-dwelling heterotrophic n2-fixing gram-negative bacterium azotobacter chroococcum ncimb 8003 (atcc 4412) (ac-8003) has been determined. it consists of 7 circular replicons totalling 5,192,291 bp comprising a circular chromosome of 4,591,803 bp and six plasmids pacx50a, b, c, d, e, f of 10,435 bp, 13,852, 62,783, 69,713, 132,724, and 311,724 bp respectively. the chromosome has a g+c content of 66.27% and the six plasmids have g+c contents of 58.1, 55.3, 56.7, 59.2, 61.9, and ... | 2015 | 26061173 |
| paenibacillus lentimorbus inoculation enhances tobacco growth and extenuates the virulence of cucumber mosaic virus. | previous studies with paenibacillus lentimorbus b-30488" (hereafter referred as b-30488), a plant growth promoting rhizobacteria (pgpr) isolated from cow's milk, revealed its capabilities to improve plant quality under normal and stress conditions. present study investigates its potential as a biocontrol agent against an economically important virus, cucumber mosaic virus (cmv), in nicotiana tabacum cv. white burley plants and delineates the physical, biophysical, biochemical and molecular pertu ... | 2016 | 26934600 |
| protein targeting to the bacterial cytoplasmic membrane. | proteins that perform their activity within the cytoplasmic membrane or outside this cell boundary must be targeted to the translocation site prior to their insertion and/or translocation. in bacteria, several targeting routes are known; the secb- and the signal recognition particle-dependent pathways are the best characterized. recently, evidence for the existence of a third major route, the twin-arg pathway, was gathered. proteins that use either one of these three different pathways possess s ... | 1999 | 10066835 |
| seaweed hydrocolloid production: an update on enzyme assisted extraction and modification technologies. | agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. the annual global production of these hydrocolloids has recently reached 100,000 tons with a gross market value just above us$ 1.1 billion. the techno-functional properties of the seaweed polysaccharides depend strictly on their unique structural make-up, notably degree and position of sulfation and presence ... | 2015 | 26023840 |
| recent trends in control methods for bacterial wilt diseases caused by ralstonia solanacearum. | previous studies have described the development of control methods against bacterial wilt diseases caused by ralstonia solanacearum. this review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. biological control agents (bcas) have been dominated by bacteria (90%) and fungi (10%). avirulent strains of r. solanacearum, pseudomonas spp., bacillus spp., and streptomyces ... | 2015 | 25762345 |
| prokaryotic nitrate reduction: molecular properties and functional distinction among bacterial nitrate reductases. | | 1999 | 10542156 |
| development and testing of a dna macroarray to assess nitrogenase (nifh) gene diversity. | a dna macroarray was developed and evaluated for its potential to distinguish variants of the dinitrogenase reductase (nifh) gene. diverse nifh gene fragments amplified from a clone library were spotted onto nylon membranes. amplified, biotinylated nifh fragments from individual clones or a natural picoplankton community were hybridized to the array and detected by chemiluminescence. a hybridization test with six individual targets mixed in equal proportions resulted in comparable relative signa ... | 2004 | 15006766 |
| improved properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) produced by comamonas sp. eb172 utilizing volatile fatty acids by regulating the nitrogen source. | this study presents the effect of carbon to nitrogen ratio (c/n) (mol/mol) on the cell growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) accumulation by comamonas sp. eb172 in 2 l fermenters using volatile fatty acids (vfa) as the carbon source. this vfa was supplemented with ammonium sulphate and yeast extract in the feeding solution to achieve c/n (mol/mol) 5, 15, 25, and 34.4, respectively. by extrapolating the c/n and the source of nitrogen, the properties of the polymers can be regula ... | 2013 | 24106698 |
| applications of biosurfactants in the petroleum industry and the remediation of oil spills. | petroleum hydrocarbons are important energy resources. however, petroleum is also a major pollutant of the environment. contamination by oil and oil products has caused serious harm, and increasing attention has been paid to the development and implementation of innovative technologies for the removal of these contaminants. biosurfactants have been extensively used in the remediation of water and soil, as well as in the main stages of the oil production chain, such as extraction, transportation, ... | 2014 | 25029542 |
| plant growth-promoting rhizobacteria inoculation to enhance vegetative growth, nitrogen fixation and nitrogen remobilisation of maize under greenhouse conditions. | plant growth-promoting rhizobacteria (pgpr) may provide a biological alternative to fix atmospheric n2 and delay n remobilisation in maize plant to increase crop yield, based on an understanding that plant-n remobilisation is directly correlated to its plant senescence. thus, four pgpr strains were selected from a series of bacterial strains isolated from maize roots at two locations in malaysia. the pgpr strains were screened in vitro for their biochemical plant growth-promoting (pgp) abilities ... | 2016 | 27011317 |
| identification of wastewater bacteria involved in the degradation of triclocarban and its non-chlorinated congener. | triclocarban (tcc) is an antimicrobial additive of personal care products that is only partially degraded during wastewater treatment. bacteria responsible for its transformation are unknown. we obtained wastewater bacteria capable of using as the sole carbon source tcc or its non-chlorinated analog, carbanilide (ncc). enrichments established using activated sludge amended with tcc and ncc, respectively, were maintained for 1 year through successive transfers. enrichments displayed exponential g ... | 2010 | 20727675 |
| advances in utilization of renewable substrates for biosurfactant production. | biosurfactants are amphiphilic molecules that have both hydrophilic and hydrophobic moieties which partition preferentially at the interfaces such as liquid/liquid, gas/liquid or solid/liquid interfaces. such characteristics enable emulsifying, foaming, detergency and dispersing properties. their low toxicity and environmental friendly nature and the wide range of potential industrial applications in bioremediation, health care, oil and food processing industries makes them a highly sought after ... | 2011 | 21906330 |
| cofactor binding protects flavodoxin against oxidative stress. | in organisms, various protective mechanisms against oxidative damaging of proteins exist. here, we show that cofactor binding is among these mechanisms, because flavin mononucleotide (fmn) protects azotobacter vinelandii flavodoxin against hydrogen peroxide-induced oxidation. we identify an oxidation sensitive cysteine residue in a functionally important loop close to the cofactor, i.e., cys69. oxidative stress causes dimerization of apoflavodoxin (i.e., flavodoxin without cofactor), and leads t ... | 2012 | 22829943 |
| the use of lacz marker in enumeration of azotobacter chroococcum in carrier based inoculants. | a transconjugant of azotobacter chroococcum mac 27 tagged with lac z(a. chroococcum mac27 l) was found to possess high levels of β-galactosidase activity constitutively. further, the lac z marker was found to be stably integrated into the chromosome of the a. chroococcum mac 27 and did not have any adverse effect on growth, nitrogen fixation and excretion of ammonia. a quick method to determine the viable cell number in broth culture and carrier based inoculants has been developed on the basis o ... | 2014 | 25242946 |
| interaction of piriformospora indica with azotobacter chroococcum. | microbial communities in rhizosphere interact with each other and form a basis of a cumulative impact on plant growth. rhizospheric microorganisms like piriformospora indica and azotobacter chroococcum are well known for their beneficial interaction with plants. these features make p. indica/a. chroococcum co-inoculation of crops most promising with respect to sustainable agriculture and to understanding the transitions in the evolution of rhizospheric microbiome. here, we investigated interacti ... | 2015 | 26350628 |
| degradation study of lindane by novel strains kocuria sp. dab-1y and staphylococcus sp. dab-1w. | this study was carried out to isolate and characterize the bacterial strains from lindane-contaminated soil and they were also assessed for their lindane-degrading potential. | 2016 | 28090433 |
| gcsr, a tyrr-like enhancer-binding protein, regulates expression of the glycine cleavage system in pseudomonas aeruginosa pao1. | glycine serves as a major source of single carbon units for biochemical reactions within bacterial cells. utilization of glycine is tightly regulated and revolves around a key group of proteins known as the glycine cleavage system (gcs). our lab previously identified the transcriptional regulator gcsr (pa2449) as being required for catabolism of glycine in the opportunistic pathogen pseudomonas aeruginosa pao1. in an effort to clarify and have an overall better understanding of the role of gcsr ... | 2016 | 27303730 |
| piriformospora indica: potential and significance in plant stress tolerance. | owing to its exceptional ability to efficiently promote plant growth, protection and stress tolerance, a mycorrhiza like endophytic agaricomycetes fungus piriformospora indica has received a great attention over the last few decades. p. indica is an axenically cultiviable fungus which exhibits its versatility for colonizing/hosting a broad range of plant species through directly manipulating plant hormone-signaling pathway during the course of mutualism. p. indica-root colonization leads to a be ... | 2016 | 27047458 |
| biosynthesis of catechol melanin from glycerol employing metabolically engineered escherichia coli. | melanins comprise a chemically-diverse group of polymeric pigments whose function is related to protection against physical and chemical stress factors. these polymers have current and potential applications in the chemical, medical, electronics and materials industries. the biotechnological production of melanins offers the possibility of obtaining these pigments in pure form and relatively low cost. in this study, escherichia coli strains were engineered to evaluate the production of melanin f ... | 2016 | 27659593 |
| comparison of nifh gene pools in soils and soil microenvironments with contrasting properties. | the similarities and differences in the structures of the nifh gene pools of six different soils (montrond, lcsa-p, vernon, dombes, lcsa-c, and thysse kaymor) and five soil fractions extracted from lcsa-c were studied. bacterial dna was directly extracted from the soils, and a region of the nifh gene was amplified by pcr and analyzed by restriction. soils were selected on the basis of differences in soil management, plant cover, and major physicochemical properties. microenvironments differed on ... | 2001 | 11319109 |
| effect of 'azotobacter' bioinoculant on the growth and substrate utilization potential of pleurotus eous seed spawn. | we investigated the effect of nitrogen fixing azotobacter bioinoculant on the mycelial growth and the rate of substrate utilization by pleurotus eous. the synergistic or antagonistic role of the microorganism during dual culturing with the mushroom or the competitor molds trichoderma viride, and trichoderma reesi was studied. azotobacter was inhibitory to the molds, which are competitive to the mushroom in the seed spawn substrate, but was synergistic towards the mushroom. the growth, substrate ... | 2005 | 24049469 |
| realm of pd-(d/e)xk nuclease superfamily revisited: detection of novel families with modified transitive meta profile searches. | pd-(d/e)xk nucleases constitute a large and highly diverse superfamily of enzymes that display little sequence similarity despite retaining a common core fold and a few critical active site residues. this makes identification of new pd-(d/e)xk nuclease families a challenging task as they usually escape detection with standard sequence-based methods. we developed a modified transitive meta profile search approach and to consider the structural diversity of pd-(d/e)xk nuclease fold more thoroughly ... | 2007 | 17584917 |
| application of denaturing high-performance liquid chromatography in microbial ecology: fermentor sludge, compost, and soil community profiling. | genetic fingerprinting methods, such as denaturing gradient gel electrophoresis (dgge), are used in microbial ecology for the analysis of mixed microbial communities but are associated with various problems. in the present study we used a new alternative method: denaturing high-performance liquid chromatography (dhplc). this method was previously shown to work with samples from water and gut flora but had not yet been applied to complex environmental samples. in contrast to other publications de ... | 2008 | 19088311 |
| application of denaturing high-performance liquid chromatography in microbial ecology: fermentor sludge, compost, and soil community profiling. | genetic fingerprinting methods, such as denaturing gradient gel electrophoresis (dgge), are used in microbial ecology for the analysis of mixed microbial communities but are associated with various problems. in the present study we used a new alternative method: denaturing high-performance liquid chromatography (dhplc). this method was previously shown to work with samples from water and gut flora but had not yet been applied to complex environmental samples. in contrast to other publications de ... | 2008 | 19088311 |
| production of thermostable invertases by aspergillus caespitosus under submerged or solid state fermentation using agroindustrial residues as carbon source. | the filamentous fungus aspergillus caespitosus was a good producer of intracellular and extracellular invertases under submerged (sbmf) or solid-state fermentation (ssf), using agroindustrial residues, such as wheat bran, as carbon source. the production of extracellular enzyme under ssf at 30°c, for 72h, was enhanced using sr salt solution (1:1, w/v) to humidify the substrate. the extracellular activity under ssf using wheat bran was around 5.5-fold higher than that obtained in sbmf (khanna med ... | 2009 | 24031406 |
| characterization of free nitrogen fixing bacteria of the genus azotobacter in organic vegetable-grown colombian soils. | 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 ou ... | 2011 | 24031700 |
| microbial communities associated with the larval gut and eggs of the western corn rootworm. | the western corn rootworm (wcr) is one of the economically most important pests of maize. a better understanding of microbial communities associated with guts and eggs of the wcr is required in order to develop new pest control strategies, and to assess the potential role of the wcr in the dissemination of microorganisms, e.g., mycotoxin-producing fungi. | 2012 | 23056182 |
| effect of soil nutrient on production and diversity of volatile terpenoids from plants. | terpenoid production (emission and storage) within foliage plays direct and indirect defensive and protective functions for the plant, mediates complex trophic relationships and controls the oxidation capacity of the atmosphere. both biotic and abiotic conditions alter terpenoid production, with herbivory, light and temperature effects being reasonably well understood. in this manuscript, the state of the science about nutrient effect on terpenoid production is reviewed. the focus is on isoprene ... | 2012 | 23097639 |
| plant growth stimulation of wheat (triticum aestivum l.) by inoculation of salinity tolerant azotobacter strains. | five salinity tolerant azotobacter strains i.e., st3, st6, st9, st17 and st24 were obtained from saline soils. these azotobacter strains were used as inoculant for wheat variety wh157 in earthen pots containing saline soil under pot house conditions, using three fertilizer treatment doses i.e., control (no fertilizer, no inoculation), 90 kg n ha(-1) and 120 kg n ha(-1). inoculation with salinity tolerant azotobacter strains caused significant increase in total nitrogen, biomass and grain yield o ... | 2013 | 24431520 |
| differences in cellulosic supramolecular structure of compositionally similar rice straw affect biomass metabolism by paddy soil microbiota. | because they are strong and stable, lignocellulosic supramolecular structures in plant cell walls are resistant to decomposition. however, they can be degraded and recycled by soil microbiota. little is known about the biomass degradation profiles of complex microbiota based on differences in cellulosic supramolecular structures without compositional variations. here, we characterized and evaluated the cellulosic supramolecular structures and composition of rice straw biomass processed under dif ... | 2013 | 23840554 |
| cell attachment on poly(3-hydroxybutyrate)-poly(ethylene glycol) copolymer produced by azotobacter chroococcum 7b. | the improvement of biomedical properties, e.g. biocompatibility, of poly(3-hydroxyalkanoates) (phas) by copolymerization is a promising trend in bioengineering. we used strain azotobacter chroococcum 7b, an effective producer of phas, for biosynthesis of not only poly(3-hydroxybutyrate) (phb) and its main copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (phb-hv), but also alternative copolymer, poly(3-hydroxybutyrate)-poly(ethylene glycol) (phb-peg). | 2013 | 23692611 |
| the terpolymer produced by azotobacter chroococcum 7b: effect of surface properties on cell attachment. | the copolymerization of poly(3-hydroxybutyrate) (phb) is a promising trend in bioengineering to improve biomedical properties, e.g. biocompatibility, of this biodegradable polymer. we used strain azotobacter chroococcum 7b, an effective producer of phb, for biosynthesis of not only homopolymer and its main copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (phb-hv), but also novel terpolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-poly(ethylene glycol) (phb-hv-peg), using sucrose as t ... | 2013 | 23468935 |
| crystal structure of dimeric flavodoxin from desulfovibrio gigas suggests a potential binding region for the electron-transferring partner. | flavodoxins, which exist widely in microorganisms, have been found in various pathways with multiple physiological functions. the flavodoxin (fld) containing the cofactor flavin mononucleotide (fmn) from sulfur-reducing bacteria desulfovibrio gigas (d. gigas) is a short-chain enzyme that comprises 146 residues with a molecular mass of 15 kda and plays important roles in the electron-transfer chain. to investigate its structure, we purified this fld directly from anaerobically grown d. gigas cell ... | 2013 | 23322018 |
| structural and phylogenetic analysis of rhodobacter capsulatus niff: uncovering general features of nitrogen-fixation (nif)-flavodoxins. | analysis of the crystal structure of niff from rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the c-terminus of the 50's loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. a phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different fu ... | 2013 | 23303276 |
| cost effective technologies and renewable substrates for biosurfactants' production. | diverse types of microbial surface active amphiphilic molecules are produced by a range of microbial communities. the extraordinary properties of biosurfactant/bioemulsifier (bs/be) as surface active products allows them to have key roles in various field of applications such as bioremediation, biodegradation, enhanced oil recovery, pharmaceutics, food processing among many others. this leads to a vast number of potential applications of these bs/be in different industrial sectors. despite the h ... | 2014 | 25566213 |
| antimicrobial action of an endophytic fungi from sophor flavescens and structure identification of its active constituent. | endophytic fungus bs002 was isolated and characterized from sophora flavescens by plate method, which has broad antimicrobial activity. isolation and trace of a new bioactive compound from the fungus' culture extracts with the method of column chromatography and tlc biological autoradiography was conducted. finally, it was identified as 6,7-(2'e) dibutenyl-5,8-dihydroxy-(z)-cyclooct-2-ene-1,4-dione by nuclear magnetic resonance, infrared and liquid chromatography-mass spectrometry. the compound ... | 2014 | 26019517 |
| morphological, biochemical and molecular characterization of twelve nitrogen-fixing bacteria and their response to various zinc concentration. | zinc is an essential micronutrient used in the form of zinc sulfate in fertilizers in the agriculture production system. nitrogen-fixing microorganisms are also of considerable value in promoting soil fertility. | 2014 | 25147702 |
| melanin from the nitrogen-fixing bacterium azotobacter chroococcum: a spectroscopic characterization. | melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. using complementary physicochemical techniques (i.e. maldi-tof, ftir absorption and cross-polarization magic angle spinning soli ... | 2014 | 24416247 |
| impact of bio-fertilizers and different levels of cadmium on the growth, biochemical contents and lipid peroxidation of plantago ovata forsk. | plantago ovata forsk. (isabgol) is a valuable medicinal plant; its seeds and shell have a significant role in pharmacy as a laxative compound. increasing soil contamination with cadmium (cd) is one of the major concerns and is responsible for toxic effects in plants. this investigation was aimed to analyze the role of biofertilizers in alleviation of cadmium stress, given at the rate of 0, 50, and 100 mg kg(-1) of soil. the plants of isabgol, were grown in pots with and without application of am ... | 2014 | 25183940 |
| comparative genomics and biological characterization of sequential pseudomonas aeruginosa isolates from persistent airways infection. | pseudomonas aeruginosa establishes life-long chronic airway infections in cystic fibrosis (cf) patients. as the disease progresses, p. aeruginosa pathoadaptive variants are distinguished from the initially acquired strain. however, the genetic basis and the biology of host-bacteria interactions leading to a persistent lifestyle of p. aeruginosa are not understood. as a model system to study long term and persistent cf infections, the p. aeruginosa rp73, isolated 16.9 years after the onset of air ... | 2015 | 26714629 |
| interrelated effects of mycorrhiza and free-living nitrogen fixers cascade up to aboveground herbivores. | aboveground plant performance is strongly influenced by belowground microorganisms, some of which are pathogenic and have negative effects, while others, such as nitrogen-fixing bacteria and arbuscular mycorrhizal fungi, usually have positive effects. recent research revealed that belowground interactions between plants and functionally distinct groups of microorganisms cascade up to aboveground plant associates such as herbivores and their natural enemies. however, while functionally distinct b ... | 2015 | 26380703 |
| transcriptional activity of the giant barrel sponge, xestospongia muta holobiont: molecular evidence for metabolic interchange. | compared to our understanding of the taxonomic composition of the symbiotic microbes in marine sponges, the functional diversity of these symbionts is largely unknown. furthermore, the application of genomic, transcriptomic, and proteomic techniques to functional questions on sponge host-symbiont interactions is in its infancy. in this study, we generated a transcriptome for the host and a metatranscriptome of its microbial symbionts for the giant barrel sponge, xestospongia muta, from the carib ... | 2015 | 25972851 |
| biological seed priming mitigates the effects of water stress in sunflower seedlings. | the sunflower (helianthus annuus l. cv. pac 36) seedlings were inoculated with plant growth promoting rhizobacteria (pgpr), viz. azotobacter chroococcum (a+), bacillus polymyxa (b+), separately and in combination of the two (ab+). relative water content and seedling growth were maximum in ab+ seedlings under control. water stress significantly decreased the rwc, growth and dry mass of non-inoculated seedlings. however, inoculated seedlings maintained higher growth even under water stress. pigmen ... | 2015 | 25964714 |
| alginate lyases from alginate-degrading vibrio splendidus 12b01 are endolytic. | alginate lyases are enzymes that degrade alginate through β-elimination of the glycosidic bond into smaller oligomers. we investigated the alginate lyases from vibrio splendidus 12b01, a marine bacterioplankton species that can grow on alginate as its sole carbon source. we identified, purified, and characterized four polysaccharide lyase family 7 alginates lyases, alya, alyb, alyd, and alye, from v. splendidus 12b01. the four lyases were found to have optimal activity between ph 7.5 and 8.5 and ... | 2015 | 25556193 |
| reactive oxygen species generation-scavenging and signaling during plant-arbuscular mycorrhizal and piriformospora indica interaction under stress condition. | a defined balance between the generation and scavenging of reactive oxygen species (ros) is essential to utilize ros as an adaptive defense response of plants under biotic and abiotic stress conditions. moreover, ros are not only a major determinant of stress response but also act as signaling molecule that regulates various cellular processes including plant-microbe interaction. in particular, rhizosphere constitutes the biologically dynamic zone for plant-microbe interactions which forms a mut ... | 2016 | 27818671 |
| identification of novel genomic islands in liverpool epidemic strain of pseudomonas aeruginosa using segmentation and clustering. | pseudomonas aeruginosa is an opportunistic pathogen implicated in a myriad of infections and a leading pathogen responsible for mortality in patients with cystic fibrosis (cf). horizontal transfers of genes among the microorganisms living within cf patients have led to highly virulent and multi-drug resistant strains such as the liverpool epidemic strain of p. aeruginosa, namely the lesb58 strain that has the propensity to acquire virulence and antibiotic resistance genes. often these genes are ... | 2016 | 27536294 |
| biosynthesis of poly(3-hydroxybutyrateco-3-hydroxy-4-methylvalerate) by strain azotobacter chroococcum 7b. | production of novel polyhydroxyalkanoates (phas), biodegradable polymers for biomedical applications, and biomaterials based on them is a promising trend in modern bioengineering. we studied the ability of an effective strain-producer azotobacter chroococcum 7b to synthesize not only poly(3-hydroxybutyrate) homopolymer (phb) and its main copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (phbv), but also a novel copolymer, poly(3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) (phb4mv). for t ... | 2016 | 27795846 |
| artemisinin-based antimalarial research: application of biotechnology to the production of artemisinin, its mode of action, and the mechanism of resistance of plasmodium parasites. | malaria is a worldwide disease caused by plasmodium parasites. a sesquiterpene endoperoxide artemisinin isolated from artemisia annua was discovered and has been accepted for its use in artemisinin-based combinatorial therapies, as the most effective current antimalarial treatment. however, the quantity of this compound produced from the a. annua plant is very low, and the availability of artemisinin is insufficient to treat all infected patients. in addition, the emergence of artemisinin-resist ... | 2016 | 27250562 |
| 4,3-α-glucanotransferase, a novel reaction specificity in glycoside hydrolase family 70 and clan gh-h. | lactic acid bacteria possess a diversity of glucansucrase (gs) enzymes that belong to glycoside hydrolase family 70 (gh70) and convert sucrose into α-glucan polysaccharides with (α1 → 2)-, (α1 → 3)-, (α1 → 4)- and/or (α1 → 6)-glycosidic bonds. in recent years 3 novel subfamilies of gh70 enzymes, inactive on sucrose but using maltodextrins/starch as substrates, have been established (e.g. gtfb of lactobacillus reuteri 121). compared to the broad linkage specificity found in gss, all gh70 starch-a ... | 2017 | 28059108 |