Publications

a hu-like gene mutation in rhizobium leguminosarum bv. viciae affects the expression of nodulation genes.	nodd is the major regulator of nod genes expression in rhizobia. previously, a hu-like protein in rhizobium leguminosarum bv. viciae has been identified to bind specifically with nod promoters and be involved in in vitro nodd transcription, but its in vivo function remained unknown. in this work we have cloned and sequenced the r. leguminosarum bv. viciae gene, named hurl, for this hu-like protein. using the e. coli-expressed hurl proteins, we proved that hurl had high affinity to several nod pr ...	2004	14731285
[bioprotection mechanisms of the lentil plant by rhizobium leguminosarum against fusarium oxysporum f. sp. lentis].	living and heat-killed bacterial cells of rhizobium leguminosarum protected totally lentil plants against infection by the pathogen fusarium oxysporum mr 84. culture filtrate of this rhizobacterium was also able to protect the plants to a high degree. however, when they were inoculated separately of the pathogen, living bacterial cells did not protect the plants whereas culture filtrate and killed bacterial cells protected them. these results suggest that rhizobium cannot protect lentil plants w ...	2003	14746271
mutational analysis of gsti protein, a glutamine synthetase translational inhibitor of rhizobium leguminosarum.	the small gsti protein (63 amino acids) of rhizobium leguminosarum inhibits the expression of the glnii (glutamine synthetase ii) gene, thus reducing the bacterial ability to assimilate ammonium. in order to identify the residues essential for its inhibitory activity, all the 53 non-alanine amino acid residues of gsti were individually mutated into alanine. based on their capacity to inhibit glnii expression (in two genetic backgrounds) three groups of mutants were identified. the first group di ...	2004	14759514
pvups1, an allantoin transporter in nodulated roots of french bean.	nodulated legumes receive their nitrogen via nitrogen-fixing rhizobia, which exist in a symbiotic relationship with the root system. in tropical legumes like french bean (phaseolus vulgaris) or soybean (glycine max), most of the fixed nitrogen is used for synthesis of the ureides allantoin and allantoic acid, the major long-distance transport forms of organic nitrogen in these species. the purpose of this investigation was to identify a ureide transporter that would allow us to further character ...	2004	14764906
[nodule bacteria].		1950	14775505
[serologic study of rhizobium; application to the problem of competition between strains].		1950	14800006
[observations on excretion products of bacterium radicicola and their vitamin properties].		1951	14859534
cell surface interactions of rhizobium bacteroids and other bacterial strains with symbiosomal and peribacteroid membrane components from pea nodules.	samples of rhizobium bacteroids isolated from pea nodule symbiosomes reacted positively with a monoclonal antibody recognizing n-linked glycan epitopes on plant glycoproteins associated with the peribacteroid membrane and peribacteroid fluid. an antiserum recognizing the symbiosomal lectin-like glycoprotein psnlec-1 also reacted positively. samples of isolated bacteroids also reacted with an antibody recognizing a glycolipid component of the peribacteroid membrane and plasma membrane. bacterial ...	2004	14964535
a dominant-negative fur mutation in bradyrhizobium japonicum.	in many bacteria, the ferric uptake regulator (fur) protein plays a central role in the regulation of iron uptake genes. because iron figures prominently in the agriculturally important symbiosis between soybean and its nitrogen-fixing endosymbiont bradyrhizobium japonicum, we wanted to assess the role of fur in the interaction. we identified a fur mutant by selecting for manganese resistance. manganese interacts with the fur protein and represses iron uptake genes. in the presence of high level ...	2004	14973020
the burkholderia cepacia epidemic strain marker is part of a novel genomic island encoding both virulence and metabolism-associated genes in burkholderia cenocepacia.	the burkholderia cepacia epidemic strain marker (bcesm) is a useful epidemiological marker for virulent b. cenocepacia strains that infect patients with cystic fibrosis. however, there was no evidence that the original marker, identified by random amplified polymorphic dna fingerprinting, contributed to pathogenicity. here we demonstrate that the bcesm is part of a novel genomic island encoding genes linked to both virulence and metabolism. the bcesm was present on a 31.7-kb low-gc-content islan ...	2004	14977960
characterization of a new internal promoter (p3) for rhizobium leguminosarum hydrogenase accessory genes hupghij.	synthesis of the rhizobium leguminosarum [nife] hydrogenase requires the participation of 16 accessory genes (hupcdefghijkhypabfcdex) besides the genes encoding the structural proteins (hupsl). transcription of hupsl is controlled by a -24/-12-type promoter (p(1)), located upstream of hups and regulated by nifa. in this work, a second -24/-12-type promoter (p(3)), located upstream of the hupg gene and transcribing hupghij genes in r. leguminosarum pea (pisum sativum l.) bacteroids, has been iden ...	2004	14993316
a rhizobium leguminosarum lipopolysaccharide lipid-a mutant induces nitrogen-fixing nodules with delayed and defective bacteroid formation.	lipopolysaccharides from pea-nodulating strain rhizobium leguminosarum by. viciae 3841, as all other members of the family rhizobiaceae with the possible exception of azorhizobium caulinodans, contains a very long chain fatty acid; 27-hydroxyoctacosanoic acid (27ohc28:0) in its lipid a region. the exact function and importance of this residue, however, is not known. in this work, a previously constructed mutant, rhizobium leguminosarum by. viciae 22, deficient in the fatty acid residue, was anal ...	2004	15000395
regulatory role of rhizobium etli cnpaf512 fnrn during symbiosis.	the rhizobium etli cnpaf512 fnrn gene was identified in the fixabcx rpon(2) region. the corresponding protein contains the hallmark residues characteristic of proteins belonging to the class ib group of fnr-related proteins. the expression of r. etli fnrn is highly induced under free-living microaerobic conditions and during symbiosis. this microaerobic and symbiotic induction of fnrn is not controlled by the sigma factor rpon and the symbiotic regulator nifa or fixlj, but it is due to positive ...	2004	15006745
diverse organization of genes of the beta-ketoadipate pathway in members of the marine roseobacter lineage.	members of the roseobacter lineage, an ecologically important marine clade within the class alpha-proteobacteria, harbor genes for the protocatechuate branch of the beta-ketoadipate pathway, a major catabolic route for lignin-related aromatic compounds. the genes of this pathway are typically clustered, although gene order varies among organisms. here we characterize genes linked to pcah and -g, which encode protocatechuate 3,4-dioxygenase, in eight closely related members of the roseobacter lin ...	2004	15006791
synthesis and characterization of carboxymethylated cyclosophoraose, and its inclusion complexation behavior.	carboxymethylated cyclosophoraoses (cm-cys) were synthesized by chemical modification of a family of neutral cyclosophoraoses isolated from rhizobium leguminosarum biovar trifolii. structural analyses of the cm-cys were carried out using nmr and ftir spectroscopies, and the molecular weight distributions were confirmed with maldi-tof mass spectrometry. based on structural characterization, native cyclosophoraoses were successfully substituted with carboxymethyl groups at the oh-4 and oh-6 of the ...	2004	15013389
regulation of pssa and pssb gene expression in rhizobium leguminosarum bv. trifolii in response to environmental factors.	exopolysaccharide (eps) produced by rhizobium leguminosarum plays an important role in indeterminate-type nodulation. the pssa gene, encoding the first glycosyl transferase and pssb, encoding inositol monophosphatase, are involved in eps synthesis and regulation in r. leguminosarum bv. trifolii. using pssa-lacz and pssb-lacz plasmid-borne transcriptional fusions, a stimulating effect of phosphate on the transcription of both genes was observed. the increase in the transcription of pssa and pssb ...	2004	15031650
phenotypic and genotypic analysis of rhizobia isolated from pasture legumes native of sardinia and asinara island.	thirty-five rhizobial strains were isolated from nodules of lotus edulis, l. ornithopodioides, l. cytisoides, hedysarum coronarium, ornithopus compressus and scorpiurus muricatus growing in sardinia and asinara island. basic characteristics applied to identification of rhizobia such as symbiotic properties, antibiotic- and salt-resistance, temperate-sensitivities, utilization of different sources of carbon and nitrogen were studied. the results from the 74 metabolic tests were used for cluster a ...	2004	15031655
similarity to peroxisomal-membrane protein family reveals that sinorhizobium and brucella baca affect lipid-a fatty acids.	sinorhizobium meliloti, a legume symbiont, and brucella abortus, a phylogenetically related mammalian pathogen, both require the bacterial-encoded baca protein to establish chronic intracellular infections in their respective hosts. we found that the bacterial baca proteins share sequence similarity with a family of eukaryotic peroxisomal-membrane proteins, including the human adrenoleukodystrophy protein, required for the efficient transport of very-long-chain fatty acids out of the cytoplasm. ...	2004	15044696
expression islands clustered on the symbiosis island of the mesorhizobium loti genome.	rhizobia are symbiotic nitrogen-fixing soil bacteria that are associated with host legumes. the establishment of rhizobial symbiosis requires signal exchanges between partners in microaerobic environments that result in mutualism for the two partners. we developed a macroarray for mesorhizobium loti maff303099, a microsymbiont of the model legume lotus japonicus, and monitored the transcriptional dynamics of the bacterium during symbiosis, microaerobiosis, and starvation. global transcriptional ...	2004	15060047
analysis of facultative lithotroph distribution and diversity on volcanic deposits by use of the large subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase.	a 492- to 495-bp fragment of the gene coding for the large subunit of the form i ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) (rbcl) was amplified by pcr from facultatively lithotrophic aerobic co-oxidizing bacteria, colorless and purple sulfide-oxidizing microbial mats, and genomic dna extracts from tephra and ash deposits from kilauea volcano, for which atmospheric co and hydrogen have been previously documented as important substrates. pcr products from the mats and volcanic site ...	2004	15066819
[the influence of lipopolysaccharides and glucans from two rhizobium leguminosarum bv. viciae strains on the formation and efficiency of their symbioses with pea plants].	the influence of lipopolysaccharides (lps), glucans, and their unseparated complexes on nodulation activity of rhizobia and efficiency of their symbioses with pea plants was studied in vegetation experiments. two rhizobium leguminosarum bv. viciae strains which differed in their symbiotic properties were used: strain 31 (fix+, efficient, moderately virulent, moderately competitive), and strain 248b (fix-, inefficient, highly virulent, highly competitive). preparations of lps-glucan complex and t ...	2004	15074042
hybf, a zinc-containing protein involved in nife hydrogenase maturation.	hypa and hypb are maturation proteins required for incorporation of nickel into the hydrogenase large subunit. to examine the functions of these proteins in nickel insertion, the hybf gene, which is a homolog of hypa essential for maturation of hydrogenases 1 and 2 from escherichia coli, was overexpressed, and the product was purified. this protein behaves like a monomer in gel filtration and contains stoichiometric amounts of zinc but insignificant or undetectable amounts of nickel and iron. in ...	2004	15090500
physiologic and proteomic evidence for a role of nitric oxide in biofilm formation by nitrosomonas europaea and other ammonia oxidizers.	no, a free radical gas, is the signal for nitrosomonas europaea cells to switch between different growth modes. at an no concentration of more than 30 ppm, biofilm formation by n. europaea was induced. no concentrations below 5 ppm led to a reversal of the biofilm formation, and the numbers of motile and planktonic (motile-planktonic) cells increased. in a proteomics approach, the proteins expressed by n. europaea were identified. comparison studies of the protein patterns of motile-planktonic a ...	2004	15090520
effects of rhizobium, arbuscular mycorrhizal fungi and anion content of simulated rain on subterranean clover.	an experiment was conducted to determine the extent to which rhizobia, mycorrhizal fungi, and anions in simulated rain affect plant growth response to acid deposition. germinating subterranean clover seeds were planted in steam-pasteurized soil in pots and inoculated with rhizobium leguminosarum, glomus intraradices, glomus etunicatum, r. leguminosarum + g. intraradices, r. leguminosarum + g. etunicatum, or no microbial symbionts. beginning 3 weeks later, plants and the soil surface were exposed ...	1996	15091411
the effect of heavy metals on dinitrogen fixation by rhizobium-white clover in a range of long-term sewage sludge amended and metal-contaminated soils.	an investigation was conducted to determine whether effective strains of rhizobium leguminosarum biovar. trifolii capable of symbiotic n2 fixation with white clover (trifolium repens) were present in a range of metal-contaminated soils. a number of historically sewage-amended sites (including experimental, pasture grassland and arable sites) were selected and compared with highly contaminated samples from abandoned heavy metal mines. many sites had metal concentrations above the limits establish ...	1993	15091894
environmental modulation of the psstnop gene expression in rhizobium leguminosarum bv. trifolii.	exopolysaccharide production by rhizobium leguminosarum bv. trifolii is required for successful establishment of nitrogen-fixing symbiosis with clover (trifolium pratense l.). using plasmid-borne transcriptional fusions of promoters of pss genes with promoterless lacz the effect of root exudate, phosphate, and ammonia on expression of psst, pssn, psso, and pssp genes in wild-type strain rtta1 background was determined. a stimulating effect of these environmental factors on psso and pssp gene exp ...	2004	15105887
identification of rhtx and fptx, novel genes encoding proteins that show homology and function in the utilization of the siderophores rhizobactin 1021 by sinorhizobium meliloti and pyochelin by pseudomonas aeruginosa, respectively.	rhizobactin 1021 is a hydroxymate siderophore produced by the soil bacterium sinorhizobium meliloti 2011. a regulon comprising rhta, encoding the outer membrane receptor protein for the ferrisiderophore; the biosynthesis operon rhbabcdef; and rhra, the ara-c-like regulator of the receptor and biosynthesis genes has been previously described. we report the discovery of a gene, located upstream of rhba and named rhtx (for "rhizobactin transport"), which is required, in addition to rhta, to confer ...	2004	15126460
bacterial communities associated with flowering plants of the ni hyperaccumulator thlaspi goesingense.	thlaspi goesingense is able to hyperaccumulate extremely high concentrations of ni when grown in ultramafic soils. recently it has been shown that rhizosphere bacteria may increase the heavy metal concentrations in hyperaccumulator plants significantly, whereas the role of endophytes has not been investigated yet. in this study the rhizosphere and shoot-associated (endophytic) bacteria colonizing t. goesingense were characterized in detail by using both cultivation and cultivation-independent te ...	2004	15128517
acquisition of an agrobacterium ri plasmid and pathogenicity by other alpha-proteobacteria in cucumber and tomato crops affected by root mat.	root mat of cucumbers and tomatoes has previously been shown to be caused by agrobacterium radiobacter strains harboring a root-inducing ri plasmid (pri). nine other pri-harboring alpha-proteobacteria have subsequently been isolated from root mat-infected crops. fatty acid profiling and partial 16s rrna sequence analysis identified three of these strains as being in the genus ochrobactrum, five as being in the genus rhizobium, and one as being in the genus sinorhizobium: an in vitro pathogenicit ...	2004	15128532
the fur-like protein mur of rhizobium leguminosarum is a mn(2+)-responsive transcriptional regulator.	in wild-type rhizobium leguminosarum, the sitabcd operon specifies a mn(2+) transporter whose expression is severely reduced in cells grown in the presence of this metal. mutations in the r. leguminosarum gene, mur (manganese uptake regulator), whose product resembles the fur transcriptional regulator, cause high-level expression of sitabcd in the presence of mn(2+). in gel-shift mobility assays, purified r. leguminosarum mur protein bound to at least two regions near the sitabcd promoter region ...	2004	15133106
purification and characterization of the aaa+ domain of sinorhizobium meliloti dctd, a sigma54-dependent transcriptional activator.	activators of sigma54-rna polymerase holoenzyme couple atp hydrolysis to formation of an open complex between the promoter and rna polymerase. these activators are modular, consisting of an n-terminal regulatory domain, a c-terminal dna-binding domain, and a central activation domain belonging to the aaa+ superfamily of atpases. the aaa+ domain of sinorhizobium meliloti c4-dicarboxylic acid transport protein d (dctd) is sufficient to activate transcription. deletion analysis of the 3' end of dct ...	2004	15150237
the sinorhizobium meliloti fur gene regulates, with dependence on mn(ii), transcription of the sitabcd operon, encoding a metal-type transporter.	sinorhizobium meliloti is an alpha-proteobacterium able to induce nitrogen-fixing nodules on roots of specific legumes. in order to propagate in the soil and for successful symbiotic interaction the bacterium needs to sequester metals like iron and manganese from its environment. the metal uptake has to be in turn tightly regulated to avoid toxic effects. in this report we describe the characterization of a chromosomal region of s. meliloti encoding the sitabcd operon and the putative regulatory ...	2004	15150249
characterization of the icmh and icmf genes required for legionella pneumophila intracellular growth, genes that are present in many bacteria associated with eukaryotic cells.	legionella pneumophila, the causative agent of legionnaires' disease, replicates intracellularly within a specialized phagosome of mammalian and protozoan host cells, and the icm/dot type iv secretion system has been shown to be essential for this process. unlike all the other known icm/dot proteins, the icmf protein, which was described before, and the icmh protein, which is characterized here, have homologous proteins in many bacteria (such as yersinia pestis, salmonella enterica, rhizobium le ...	2004	15155646
the acidic nature of the ccmg redox-active center is important for cytochrome c maturation in escherichia coli.	cytochrome c biogenesis in escherichia coli is a complex process requiring at least eight genes (ccmabcdefgh). one of these genes, ccmg, encodes a thioredoxin-like protein with unusually specific redox activity. here, we investigate the basis for ccmg function and demonstrate the importance of acidic residues surrounding the redox-active center.	2004	15175318
genome organization and localization of the puflm genes of the photosynthesis reaction center in phylogenetically diverse marine alphaproteobacteria.	genome organization, plasmid content and localization of the puflm genes of the photosynthesis reaction center were studied by pulsed-field gel electrophoresis (pfge) in marine phototrophic alphaproteobacteria. both anaerobic phototrophs (rhodobacter veldkampii and rhodobacter sphaeroides) and strictly aerobic anoxygenic phototrophs from the roseobacter-sulfitobacter-silicibacter clade (roseivivax halodurans, roseobacter litoralis, staleya guttiformis, roseovarius tolerans, and five new strains ...	2004	15184132
use of sinorhizobium meliloti as an indicator for specific detection of long-chain n-acyl homoserine lactones.	population-density-dependent gene expression in gram-negative bacteria involves the production of signal molecules characterized as n-acyl homoserine lactones (ahls). the synthesis of ahls by numerous microorganisms has been identified by using biosensor strains based on the agrobacterium tumefaciens and chromobacterium violaceum quorum-sensing systems. the symbiotic nitrogen-fixing bacterium sinorhizobium meliloti is rapidly becoming a model organism for the study of quorum sensing. this organi ...	2004	15184178
infection and invasion of roots by symbiotic, nitrogen-fixing rhizobia during nodulation of temperate legumes.	bacteria belonging to the genera rhizobium, mesorhizobium, sinorhizobium, bradyrhizobium, and azorhizobium (collectively referred to as rhizobia) grow in the soil as free-living organisms but can also live as nitrogen-fixing symbionts inside root nodule cells of legume plants. the interactions between several rhizobial species and their host plants have become models for this type of nitrogen-fixing symbiosis. temperate legumes such as alfalfa, pea, and vetch form indeterminate nodules that aris ...	2004	15187185
the influence of rhizobium and arbuscular mycorrhizal fungi on nitrogen and phosphorus accumulation by vicia faba.	the aim of this study was to investigate the effects of the interactions between the microbial symbionts, rhizobium and arbuscular mycorrhizal fungi (amf) on n and p accumulation by broad bean (vicia faba) and how increased n and p content influence biomass production, leaf area and net photosynthetic rate.	2004	15205177
modified rp4 and tn5-mob derivatives for facilitated manipulation of large plasmids in gram-negative bacteria.	we have constructed a set of rp4 (nms/tcs) and tn5-mob derivatives which have applications in experiments involving mobilization of replicons in many gram-negative organisms. the different selection markers of the rp4 and tn5-mob derivatives include streptomycin, chloramphenicol, gentamicin, and spectinomycin resistance as well as mercury resistance, and a constitutively expressed lacz gene. this choice of markers allows the use of these derivatives in bacteria which are naturally resistant to m ...	2004	15212888
cloning and characterization of ce/8a gene from rhizobium leguminosarum bv. trifolii 1536.	to isolate the cellulase gene from rhizobium leguminosarum bv. trifolii 1536.	2004	15214728
biofilms 2003: emerging themes and challenges in studies of surface-associated microbial life.		2004	15231774
characterization of nopp, a type iii secreted effector of rhizobium sp. strain ngr234.	the type three secretion system (ttss) encoded by pngr234a, the symbiotic plasmid of rhizobium sp. strain ngr234, is responsible for the flavonoid- and nodd1-dependent secretion of nodulation outer proteins (nops). abolition of secretion of all or specific nops significantly alters the nodulation ability of ngr234 on many of its hosts. in the closely related strain rhizobium fredii usda257, inactivation of the ttss modifies the host range of the mutant so that it includes the improved glycine ma ...	2004	15231809
identification of campylobacter jejuni atcc 43431-specific genes by whole microbial genome comparisons.	this study describes a novel approach to identify unique genomic dna sequences from the unsequenced strain c. jejuni atcc 43431 by comparison with the sequenced strain c. jejuni nctc 11168. a shotgun dna microarray was constructed by arraying 9,600 individual dna fragments from a c. jejuni atcc 43431 genomic library onto a glass slide. dna fragments unique to c. jejuni atcc 43431 were identified by competitive hybridization to the array with genomic dna of c. jejuni nctc 11168. the plasmids cont ...	2004	15231810
fur is involved in manganese-dependent regulation of mnta (sita) expression in sinorhizobium meliloti.	fur is a transcriptional regulator involved in iron-dependent control of gene expression in many bacteria. in this work we analyzed the phenotype of a fur mutant in sinorhizobium meliloti, an alpha-proteobacterium that fixes n(2) in association with host plants. we demonstrated that some functions involved in high-affinity iron transport, siderophore production, and iron-regulated outer membrane protein expression respond to iron in a fur-independent manner. however, manganese-dependent expressi ...	2004	15240318
accumulation of lipochitin oligosaccharides and nodd-activating compounds in an efficient plant--rhizobium nodulation assay.	during legume plant--rhizobium spp. interactions, leading to the formation of nitrogen-fixing root nodules, the two major determinants of host plant-specificity are plant-produced nod gene inducers (nodd protein activating compounds) and bacterial lipochitin oligosaccharides (lcos or nod factors). in a time course, we describe the accumulation of lcos in an efficient nodulation assay with vicia sativa subsp. nigra and rhizobium leguminosarum, in connection with the presence of nodd-activating co ...	2004	15242176
regulation of expression of symbiotic genes in rhizobium sp. ngr234.	research in the field of rhizobium-legume symbiosis faces a new challenge: integrate the wealth of information generated by genomic projects. the goal: apprehend the complexity of the molecular mechanisms involved in symbiotic associations. at the time of writing, the genomes of three micro-symbionts (bradyrhizobium japonicum, mesorhizobium loti and sinorhizobium meliloti) have been sequenced, and two more (those of rhizobium leguminosarum and rhizobium etli) will be completed in the near future ...	2003	15242276
diversity and specificity of rhizobium leguminosarum biovar viciae on wild and cultivated legumes.	the symbiotic partnerships between legumes and their root-nodule bacteria (rhizobia) vary widely in their degree of specificity, but the underlying reasons are not understood. to assess the potential for host-range evolution, we have investigated microheterogeneity among the shared symbionts of a group of related legume species. host specificity and genetic diversity were characterized for a soil population of rhizobium leguminosarum biovar viciae (rlv) sampled using six wild vicia and lathyrus ...	2004	15245415
cyclic diguanylate (c-di-gmp) regulates vibrio cholerae biofilm formation.	while studying virulence gene regulation in vibrio cholerae during infection of the host small intestine, we identified viea as a two-component response regulator that contributes to activating expression of cholera toxin. here we report that viea represses transcription of vibrio exopolysaccharide synthesis (vps) genes involved in biofilm formation by a mechanism independent of its phosphorelay and dna-binding activities. viea controls the intracellular concentration of the cyclic nucleotide se ...	2004	15255898
a novel p-nitrophenol degradation gene cluster from a gram-positive bacterium, rhodococcus opacus sao101.	p-nitrophenol (4-np) is recognized as an environmental contaminant; it is used primarily for manufacturing medicines and pesticides. to date, several 4-np-degrading bacteria have been isolated; however, the genetic information remains very limited. in this study, a novel 4-np degradation gene cluster from a gram-positive bacterium, rhodococcus opacus sao101, was identified and characterized. the deduced amino acid sequences of npcb, npca, and npcc showed identity with phenol 2-hydroxylase compon ...	2004	15262926
indole-3-acetic acid biosynthesis is deficient in gluconacetobacter diazotrophicus strains with mutations in cytochrome c biogenesis genes.	gluconacetobacter diazotrophicus is an endophyte of sugarcane frequently found in plants grown in agricultural areas where nitrogen fertilizer input is low. recent results from this laboratory, using mutant strains of g. diazotrophicus unable to fix nitrogen, suggested that there are two beneficial effects of g. diazotrophicus on sugarcane growth: one dependent and one not dependent on nitrogen fixation. a plant growth-promoting substance, such as indole-3-acetic acid (iaa), known to be produced ...	2004	15292139
the luxr homolog expr, in combination with the sin quorum sensing system, plays a central role in sinorhizobium meliloti gene expression.	quorum sensing, a population density-dependent mechanism for bacterial communication and gene regulation, plays a crucial role in the symbiosis between alfalfa and its symbiont sinorhizobium meliloti. the sin system, one of three quorum sensing systems present in s. meliloti, controls the production of the symbiotically active exopolysaccharide eps ii. based on dna microarray data, the sin system also seems to regulate a multitude of s. meliloti genes, including genes that participate in low-mol ...	2004	15292148
effectivity of host-rhizobium leguminosarum symbiosis in soils receiving sewage water containing heavy metals.	disposal of sewage water in cultivated soils often containing considerable amount of potentially toxic metals such as cu, zn, ni, cd, pb and cr can be beneficial or harmful to plant growth, rhizobial survival, nodulation and nitrogen fixation. soil samples from 14 such locations were collected. symbiotic effectivity of host-rhizobium leguminosarum symbiosis in these soils was assessed. the total metal contents of cd, cu, zn and ni in all the 14 samples collected from farmer's fields receiving se ...	2004	15293945
biogeography, evolution, and diversity of epibionts in phototrophic consortia.	motile phototrophic consortia are highly regular associations in which numerous cells of green sulfur bacteria surround a flagellated colorless beta-proteobacterium in the center. to date, seven different morphological types of such consortia have been described. in addition, two immotile associations involving green sulfur bacteria are known. by employing a culture-independent approach, different types of phototrophic consortia were mechanically isolated by micromanipulation from 14 freshwater ...	2004	15294820
control of nodule number by the phytohormone abscisic acid in the roots of two leguminous species.	the effects of the phytohormone abscisic acid (aba) on plant growth and root nodule formation were analyzed in trifolium repense (white clover) and lotus japonicus, which form indeterminate and determinate nodules, respectively. in t. repense, although the number of nodules formed after inoculation with rhizobium leguminosarum bv. trifolii strain 4s (wild type) was slightly affected by exogenous aba, those formed by strain h1(pc4s8), which forms ineffective nodules, were dramatically reduced 28 ...	2004	15295075
[functional activity of exoglycans from rhizobium leguminosarum bv. viciae 250a and its nitrogen-resistant mutant m-71 during the formation of legume-rhizobia symbiosis against a high-nitrogen background].	the functional activity of the exoglycan complex (egc) polysaccharides from rhizobium leguminosarum bv. viciae 250a and its nitrogen-resistant mutant m-71 capable of inducing the formation of nitrogen-fixing nodules on pea roots against a high-nitrogen background (4.8 mm no3-) was studied in vegetation tests. for this purpose, the bacterial inoculum washed free of its own exoglycans was supplemented with egc of this or another strain grown in the presence of 6 or 20 mm nitrate. the best symbioti ...	2004	15315237
cloning and expression of afpa, a gene encoding an antifreeze protein from the arctic plant growth-promoting rhizobacterium pseudomonas putida gr12-2.	the arctic plant growth-promoting rhizobacterium pseudomonas putida gr12-2 secretes an antifreeze protein (afp) that promotes survival at subzero temperatures. the afp is unusual in that it also exhibits a low level of ice nucleation activity. a dna fragment with an open reading frame encoding 473 amino acids was cloned by pcr and inverse pcr using primers designed from partial amino acid sequences of the isolated afp. the predicted gene product, afpa, had a molecular mass of 47.3 kda, a pi of 3 ...	2004	15317770
identification of functional mob regions in rhizobium etli: evidence for self-transmissibility of the symbiotic plasmid pretcfn42d.	an approach originally designed to identify functional origins of conjugative transfer (orit or mob) in a bacterial genome (j. a. herrera-cervera, j. m. sanjuán-pinilla, j. olivares, and j. sanjuán, j. bacteriol. 180:4583-4590, 1998) was modified to improve its reliability and prevent selection of undesired false mob clones. by following this modified approach, we were able to identify two functional mob regions in the genome of rhizobium etli cfn42. one corresponds to the recently characterized ...	2004	15317780
molecular and functional characterization of the azorhizobium caulinodans ors571 hydrogenase gene cluster.	in this work, we report the cloning and sequencing of the azorhizobium caulinodans ors571 hydrogenase gene cluster. sequence analysis revealed the presence of 20 open reading frames huptuvhypfhupslcdfghjk hypabhuprhypcdehupe. the physical and genetic organization of a. caulinodans ors571 hydrogenase system suggests a close relatedness to that of rhodobacter capsulatus. in contrast to the latter species, a gene homologous to rhizobium leguminosarum hupe was identified downstream of the hyp operon ...	2004	15321689
novel modification of lipid a of francisella tularensis.	we have investigated the lipid a of francisella tularensis subsp. holarctica strain 1547-57, a type b strain, by using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, nanoelectrospray quadrupole ion-trap mass spectrometry, and chemical methods. in accordance with the previously published structures of the lipid a from f. tularensis live vaccine strain (lvs) (atcc 29684) (e. vinogradov et al., eur. j. biochem. 269:6112-6118, 2002), all of the major lipid a forms from ...	2004	15322031
analysis of rhizobium etli and of its symbiosis with wild phaseolus vulgaris supports coevolution in centers of host diversification.	common beans (phaseolus vulgaris) comprise three major geographic genetic pools, one in mexico, central america, and colombia, another in the southern andes, and a third in ecuador and northern peru. species rhizobium etli is the predominant rhizobia found symbiotically associated with beans in the americas. we have found polymorphism in the common nodulation gene nodc among r. etli strains from a wide range of geographical origins, which disclosed three nodc types. the different nodc alleles in ...	2004	15340138
complexity of phenotypes and symbiotic behaviour of rhizobium leguminosarum biovar trifolii exopolysaccharide mutants.	rhizobium leguminosarum biovar trifolii strain ta1 polysaccharide synthesis (pss) mutants in the pssd, pssp, psst and psso genes and altered in exopolysaccharide (eps) synthesis were investigated. eps-deficient mutants were also changed in lipopolysaccharide structure. all mutants exhibited varied sensitivities to detergents, ethanol and antibiotics, thus indicating changes in bacterial membrane integrity. using pss mutants marked with the gusa gene, eps-deficient mutants were found to have abno ...	2004	15349716
enantioseparation using sulfated cyclosophoraoses as a novel chiral additive in capillary electrophoresis.	highly sulfated cyclosophoraoses (hs-cys) were synthesized by the chemical modification of a family of neutral cyclosophoraoses isolated from rhizobium leguminosarum bv. trifolii. the hs-cys were then analytically characterized using fourier transform-infrared spectroscopy and elemental analysis. these hs-cys were successfully used as a novel chiral additive, in low-ph aqueous background electrolytes, for capillary electrophoretic separation of five basic chiral drugs such as arterenol, atenolol ...	2004	15351997
a francisella tularensis pathogenicity island required for intramacrophage growth.	francisella tularensis is a gram-negative, facultative intracellular pathogen that causes the highly infectious zoonotic disease tularemia. we have discovered a ca. 30-kb pathogenicity island of f. tularensis (fpi) that includes four large open reading frames (orfs) of 2.5 to 3.9 kb and 13 orfs of 1.5 kb or smaller. previously, two small genes located near the center of the fpi were shown to be needed for intramacrophage growth. in this work we show that two of the large orfs, located toward the ...	2004	15375123
symbiotic autoregulation of nifa expression in rhizobium leguminosarum bv. viciae.	nifa is the general transcriptional activator of nitrogen fixation genes in diazotrophic bacteria. in rhizobium leguminosarum bv. viciae upm791, the nifa gene is part of a gene cluster (orf71 orf79 fixw orf5 fixabcx nifab) separated by 896 bp from an upstream and divergent truncated duplication of nifh (deltanifh). symbiotic expression analysis of genomic nifa::lacz fusions revealed that in strain upm791 nifa is expressed mainly from a sigma54-dependent promoter (p(nifa1)) located upstream of or ...	2004	15375140
an energy taxis transducer promotes root colonization by azospirillum brasilense.	motility responses triggered by changes in the electron transport system are collectively known as energy taxis. in azospirillum brasilense, energy taxis was shown to be the principal form of locomotor control. in the present study, we have identified a novel chemoreceptor-like protein, named tlp1, which serves as an energy taxis transducer. the tlp1 protein is predicted to have an n-terminal periplasmic region and a cytoplasmic c-terminal signaling module homologous to those of other chemorecep ...	2004	15375141
involvement of exo5 in production of surface polysaccharides in rhizobium leguminosarum and its role in nodulation of vicia sativa subsp. nigra.	analysis of two exopolysaccharide-deficient mutants of rhizobium leguminosarum, rbl5808 and rbl5812, revealed independent tn5 transposon integrations in a single gene, designated exo5. as judged from structural and functional homology, this gene encodes a udp-glucose dehydrogenase responsible for the oxidation of udp-glucose to udp-glucuronic acid. a mutation in exo5 affects all glucuronic acid-containing polysaccharides and, consequently, all galacturonic acid-containing polysaccharides. exo5-d ...	2004	15375143
legionella pneumophila dotu and icmf are required for stability of the dot/icm complex.	legionella pneumophila utilizes a type iv secretion system (t4ss) encoded by 26 dot/icm genes to replicate inside host cells and cause disease. in contrast to all other l. pneumophila dot/icm genes, dotu and icmf have homologs in a wide variety of gram-negative bacteria, none of which possess a t4ss. instead, dotu and icmf orthologs are linked to a locus encoding a conserved cluster of proteins designated icmf-associated homologous proteins, which has been proposed to constitute a novel cell sur ...	2004	15385502
expression of an exogenous 1-aminocyclopropane-1-carboxylate deaminase gene in sinorhizobium meliloti increases its ability to nodulate alfalfa.	1-aminocyclopropane-1-carboxylate (acc) deaminase has been found in various plant growth-promoting rhizobacteria, including rhizobia. this enzyme degrades acc, the immediate precursor of ethylene, and thus decreases the biosynthesis of ethylene in higher plants. the acc deaminase of rhizobium leguminosarum bv. viciae 128c53k was previously reported to be able to enhance nodulation of peas. the acc deaminase structural gene (acds) and its upstream regulatory gene, a leucine-responsive regulatory ...	2004	15466529
unexpectedly diverse mesorhizobium strains and rhizobium leguminosarum nodulate native legume genera of new zealand, while introduced legume weeds are nodulated by bradyrhizobium species.	the new zealand native legume flora are represented by four genera, sophora, carmichaelia, clianthus, and montigena. the adventive flora of new zealand contains several legume species introduced in the 19th century and now established as serious invasive weeds. until now, nothing has been reported on the identification of the associated rhizobia of native or introduced legumes in new zealand. the success of the introduced species may be due, at least in part, to the nature of their rhizobial sym ...	2004	15466541
transcriptional analysis of biofilm formation processes in the anaerobic, hyperthermophilic bacterium thermotoga maritima.	thermotoga maritima, a fermentative, anaerobic, hyperthermophilic bacterium, was found to attach to bioreactor glass walls, nylon mesh, and polycarbonate filters during chemostat cultivation on maltose-based media at 80 degrees c. a whole-genome cdna microarray was used to examine differential expression patterns between biofilm and planktonic populations. mixed-model statistical analysis revealed differential expression (twofold or more) of 114 open reading frames in sessile cells (6% of the ge ...	2004	15466556
comparison of different primer sets for use in automated ribosomal intergenic spacer analysis of complex bacterial communities.	itsf and itsreub, constituting a new primer set designed for the amplification of the 16s-23s rrna intergenic transcribed spacers, have been compared with primer sets consisting of 1406f and 23sr (m. m. fisher and e. w. triplett, appl. environ. microbiol. 65:4630-4636, 1999) and s-d-bact-1522-b-s-20 and l-d-bact-132-a-a-18 (l. ranjard et al., appl. environ. microbiol. 67:4479-4487, 2001), previously proposed for automated ribosomal intergenic spacer analysis (arisa) of complex bacterial communit ...	2004	15466561
persistence of streptococcus mutans in stationary-phase batch cultures and biofilms.	streptococcus mutans is a member of oral plaque biofilms and is considered the major etiological agent of dental caries. we have characterized the survival of s. mutans strain ua159 in both batch cultures and biofilms. bacteria grown in batch cultures in a chemically defined medium, fmc, containing an excess of glucose or sucrose caused the ph to decrease to 4.0 at the entry into stationary phase, and they survived for about 3 days. survival was extended up to 11 days when the medium contained a ...	2004	15466565
repressor mutant forms of the azospirillum brasilense ntrc protein.	the azospirillum brasilense mutant strains fp8 and fp9, after treatment with nitrosoguanidine, showed a null nif phenotype and were unable to use nitrate as their sole nitrogen source. sequencing of the ntrc genes revealed single nucleotide mutations in the ntrc nucleotide-binding site. the phenotypes of these strains are discussed in relation to their genotypes.	2004	15466584
gas chromatography-mass spectrometry analysis of indoleacetic acid and tryptophan following aqueous chloroformate derivatisation of rhizobium exudates.	a new method for preparing alkyl esters of indole-3-acetic acid (iaa) in aqueous solution is adapted from the chloroformate method originally described by husek for the analysis of amino acids. this method has the significant advantage of avoiding the generation and use of diazomethane, and is done in aqueous solution without the need to dry the sample with concomitant non-specific losses of iaa. the effectiveness of this method is demonstrated by its use in an isotope dilution gas chromatograph ...	2004	15474378
three groel homologues from rhizobium leguminosarum have distinct in vitro properties.	the groel molecular chaperone of escherichia coli and its cofactor groes are highly conserved, and are required for the folding of many proteins. most but not all bacteria express single groel and groes proteins. rhizobium leguminosarum strain a34 encodes three complete operons encoding homologues to groel and groes. we have used circular dichroism and measurement of atpase activity to compare the stabilities of these chaperonins after expression in and purification from e. coli. significant dif ...	2004	15474501
periplasmic cleavage and modification of the 1-phosphate group of helicobacter pylori lipid a.	pathogenic bacteria modify the lipid a portion of their lipopolysaccharide to help evade the host innate immune response. modification of the negatively charged phosphate groups of lipid a aids in resistance to cationic antimicrobial peptides targeting the bacterial cell surface. the lipid a of helicobacter pylori contains a phosphoethanolamine (petn) unit directly linked to the 1-position of the disaccharide backbone. this is in contrast to the petn units found in other pathogenic gram-negative ...	2004	15489235
auxin transport inhibition precedes root nodule formation in white clover roots and is regulated by flavonoids and derivatives of chitin oligosaccharides.	the expression of the auxin responsive reporter construct, gh3:gusa, was examined in transgenic white clover plants to assess changes in the auxin balance during the earliest stages of root nodule formation. reporter gene expression was monitored at marked locations after the application of bacteria or signal molecules using two precise inoculation techniques: spot-inoculation and a novel method for ballistic microtargeting. changes in gh3:gusa expression were monitored after the inoculation of ...	1998	15494052
rhizobium leguminosarum methyl-accepting chemotaxis protein genes are down-regulated in the pea nodule.	regulation of methyl-accepting chemotaxis protein (mcp) genes of rhizobium leguminosarum was studied under symbiotic conditions. transcriptional fusions using both beta-galactosidase and beta-glucuronidase genes within two different mcp genes demonstrated that mcp expression decreased significantly during nodulation. immunoblots using an anti-mcp antibody detected mcps in free-living cells but not in bacteroids. down-regulation during nodulation was not dependent upon known regulatory proteins i ...	2004	15502966
transfer of the symbiotic plasmid of rhizobium etli cfn42 requires cointegration with p42a, which may be mediated by site-specific recombination.	plasmid p42a from rhizobium etli cfn42 is self-transmissible and indispensable for conjugative transfer of the symbiotic plasmid (psym). most psym transconjugants also inherit p42a. psym transconjugants that lack p42a always contain recombinant psyms, which we designated rpsyms. rpsyms do not contain some psym segments and instead have p42a sequences, including the replication and transfer regions. these novel recombinant plasmids are compatible with wild-type psym, incompatible with p42a, and ...	2004	15516565
[the effect of the carbohydrate components of pea roots on the enzymatic activity of the surface agglutinins of rhizobium leguminosarum bv. viciae 252].	the interaction of the surface agglutinins of rhizobium leguminosarum by. viciae 252 with the carbohydrate components of host pea roots alters the beta-glucosidase and proteolytic activities of the agglutinins.	2004	15521170
the c-terminal receiver domain of the rhizobium leguminosarum bv. viciae fixl protein is required for free-living microaerobic induction of the fnrn promoter.	the rhizobium leguminosarum bv. viciae vf39 fixl protein belongs to a distinct group of hybrid regulatory sensor proteins that bear a covalently linked c-terminal receiver domain. fixl has an unorthodox histidine kinase domain, which is shared with many other hybrid regulators. the purified fixl protein had autophosphorylation activity. a truncated protein, lacking the receiver domain, had a much-reduced autophosphorylation activity. however, this truncated protein still efficiently phosphorylat ...	2004	15528657
a genetic locus necessary for rhamnose uptake and catabolism in rhizobium leguminosarum bv. trifolii.	rhizobium leguminosarum bv. trifolii mutants unable to catabolize the methyl-pentose rhamnose are unable to compete effectively for nodule occupancy. in this work we show that the locus responsible for the transport and catabolism of rhamnose spans 10,959 bp. mutations in this region were generated by transposon mutagenesis, and representative mutants were characterized. the locus contains genes coding for an abc-type transporter, a putative dehydrogenase, a probable isomerase, and a sugar kinas ...	2004	15576793
"neural networks" in bacteria: making connections.		2005	15601685
luxr homolog avhr in agrobacterium vitis affects the development of a grape-specific necrosis and a tobacco hypersensitive response.	the luxr homolog avir in agrobacterium vitis strain f2/5 was recently shown to be associated with induction of a hypersensitive response (hr) on tobacco and necrosis on grape plants, indicating that the responses are regulated by quorum sensing. we now report a second luxr homolog, avhr, whose disruption (mutant m1320) results in hr-negative and reduced grape necrosis phenotypes. the deduced avhr protein has characteristic autoinducer binding and dna binding domains and is unique among reported ...	2005	15601702
the kata catalase gene is regulated by oxyr in both free-living and symbiotic sinorhizobium meliloti.	the characterization of an oxyr insertion mutant provides evidences that kata, which encodes the unique h2o2-inducible hpii catalase, is regulated by oxyr not only in free-living sinorhizobium meliloti but also in symbiotic s. meliloti. moreover, oxyr is expressed independently of exogenous h2o2 and downregulates its own expression in s. meliloti.	2005	15601722
diversity of green-like and red-like ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes (cbbl) in differently managed agricultural soils.	a pcr-based approach was developed to detect ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) form i large-subunit genes (cbbl) as a functional marker of autotrophic bacteria that fix carbon dioxide via the calvin-benson-bassham cycle. we constructed two different primer sets, targeting the green-like and red-like phylogenetic groups of cbbl genes. the diversity of these cbbl genes was analyzed by the use of three differently managed agricultural soils from a long-term field experiment. ...	2005	15640185
phylogenetic analysis of the genera bradyrhizobium, mesorhizobium, rhizobium and sinorhizobium on the basis of 16s rrna gene and internally transcribed spacer region sequences.	a total of 128 strains was isolated from more than 23 legume hosts in korea. phylogenetic relationships between these korean isolates and reference strains of the genera bradyrhizobium, mesorhizobium, rhizobium and sinorhizobium were analysed using their 16s rrna gene and internally transcribed spacer (its) region sequences. among the bradyrhizobium strains, dendrograms based on both the 16s rrna gene and its region sequences produced two main groups. the its tree yielded at least two new cluste ...	2005	15653885
anaerobic regulation of hydrogenase transcription in different bacteria.	hydrogen metabolism is closely related to other important metabolic and energetic processes of bacterial cells, such as photosynthesis, anaerobic respiration and sulphur metabolism. even small environmental changes influence these networks through different regulatory systems. the presence or absence of oxygen is one of the most important signals; how the cascades evolved to transmit this signal in different bacteria is summarized. in many instances, hydrogen is released only under anoxic condit ...	2005	15667258
molecular characterization of uptake hydrogenase in frankia.	a molecular characterization of uptake hydrogenase in frankia was performed by using two-dimensional gel electrophoresis, matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry, pcr amplification and southern blotting. a polypeptide of approx. 60 kda was recognized in frankia ugl011102, avci1 and kb5 on the two-dimensional gel by blotting with ralstonia eutropha (hox g) antibody. further analysis by ms resulted in a peptide 'fingerprint', which was similar to the membrane-b ...	2005	15667266
genetics and biotechnology of the h(2)-uptake [nife] hydrogenase from rhizobium leguminosarum bv. viciae, a legume endosymbiotic bacterium.	a limited number of strains belonging to several genera of rhizobiaceae are capable of expressing a hydrogenase system that allows partial or full recycling of hydrogen evolved by nitrogenase, thus increasing the energy efficiency of the nitrogen fixation process. this review is focused on the genetics and biotechnology of the hydrogenase system from rhizobium leguminosarum bv. viciae, a frequent inhabitant of european soils capable of establishing symbiotic association with peas, lentils, vetch ...	2005	15667275
role of polyhydroxybutyrate and glycogen as carbon storage compounds in pea and bean bacteroids.	rhizobium leguminosarum synthesizes polyhydroxybutyrate and glycogen as its main carbon storage compounds. to examine the role of these compounds in bacteroid development and in symbiotic efficiency, single and double mutants of r. leguminosarum bv. viciae were made which lack polyhydroxybutyrate synthase (phac), glycogen synthase (glga), or both. for comparison, a single phac mutant also was isolated in a bean-nodulating strain of r. leguminosarum bv. phaseoli. in one large glasshouse trial, th ...	2005	15672820
the genome sequence of xanthomonas oryzae pathovar oryzae kacc10331, the bacterial blight pathogen of rice.	the nucleotide sequence was determined for the genome of xanthomonas oryzae pathovar oryzae (xoo) kacc10331, a bacterium that causes bacterial blight in rice (oryza sativa l.). the genome is comprised of a single, 4 941 439 bp, circular chromosome that is g + c rich (63.7%). the genome includes 4637 open reading frames (orfs) of which 3340 (72.0%) could be assigned putative function. orthologs for 80% of the predicted xoo genes were found in the previously reported x.axonopodis pv. citri (xac) a ...	2005	15673718
glnd is essential for nifa activation, ntrb/ntrc-regulated gene expression, and posttranslational regulation of nitrogenase activity in the photosynthetic, nitrogen-fixing bacterium rhodospirillum rubrum.	glnd is a bifunctional uridylyltransferase/uridylyl-removing enzyme and is thought to be the primary sensor of nitrogen status in the cell. it plays an important role in nitrogen assimilation and metabolism by reversibly regulating the modification of p(ii) proteins, which in turn regulate a variety of other proteins. we report here the characterization of glnd mutants from the photosynthetic, nitrogen-fixing bacterium rhodospirillum rubrum and the analysis of the roles of glnd in the regulation ...	2005	15687189
a polysaccharide deacetylase homologue, pdaa, in bacillus subtilis acts as an n-acetylmuramic acid deacetylase in vitro.	a polysaccharide deacetylase homologue, pdaa, was determined to act as an n-acetylmuramic acid deacetylase in vitro. histidine-tagged truncated pdaa (with the putative signal sequence removed) was overexpressed in escherichia coli cells and purified. measurement of deacetylase activity showed that pdaa could deacetylate peptidoglycan treated with n-acetylmuramoyl-l-alanine amidase cwlh but could not deacetylate peptidoglycan treated with or without dl-endopeptidase lytf (cwle). reverse-phase hig ...	2005	15687192
ectoine-induced proteins in sinorhizobium meliloti include an ectoine abc-type transporter involved in osmoprotection and ectoine catabolism.	to understand the mechanisms of ectoine-induced osmoprotection in sinorhizobium meliloti, a proteomic examination of s. meliloti cells grown in minimal medium supplemented with ectoine was undertaken. this revealed the induction of 10 proteins. the protein products of eight genes were identified by using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. five of these genes, with four other genes whose products were not detected on two-dimensional gels, belong to the s ...	2005	15687193
lipopolysaccharides as a communication signal for progression of legume endosymbiosis.	establishment of a successful symbiosis between rhizobia and legumes results from an elaborate molecular dialogue between both partners. bacterial nodulation (nod) factors are indispensable for initiating plant responses, whereas bacterial surface polysaccharides are important for infection progression and nodule development. the mutant ors571-oac2 of azorhizobium caulinodans, affected in its surface polysaccharides, provokes a defective interaction with its host sesbania rostrata. ors571-oac2 i ...	2005	15699329
characteristics of rhizobia nodulating beans in the central region of minnesota.	until recently, beans (phaseolus vulgaris l.) grown in minnesota were rarely inoculated. because of this, we hypothesized that bean rhizobia collected in minnesota would either share characteristics identifiable with rhizobium etli of mesoamerican or andean origin, introduced into the region as seed-borne contaminants, or be indigenous rhizobia from prairie species, such as dalea spp. the latter organisms have been shown to nodulate and fix n2 with phaseolus vulgaris. rhizobia recovered from the ...	2004	15714233
protein domains and architectural innovation in plant-associated proteobacteria.	evolution of new complex biological behaviour tends to arise by novel combinations of existing building blocks. the functional and evolutionary building blocks of the proteome are protein domains, the function of a protein being dependent on its constituent domains. we clustered completely-sequenced proteomes of prokaryotes on the basis of their protein domain content, as defined by pfam (release 16.0). this revealed that, although there was a correlation between phylogeny and domain content, ot ...	2005	15715905
influence of starvation on potential ammonia-oxidizing activity and amoa mrna levels of nitrosospira briensis.	the effect of short-term ammonia starvation on nitrosospira briensis was investigated. the ammonia-oxidizing activity was determined in a concentrated cell suspension with a nox biosensor. the apparent half-saturation constant [km(app)] value of the nh3 oxidation of n. briensis was 3 microm nh3 for cultures grown both in continuous and batch cultures as determined by a nox biosensor. cells grown on the wall of the vessel had a lower km(app) value of 1.8 microm nh3. nonstarving cultures of n. bri ...	2005	15746329
rhizobial 16s rrna and dnak genes: mosaicism and the uncertain phylogenetic placement of rhizobium galegae.	the phylogenetic relatedness among 12 agriculturally important species in the order rhizobiales was estimated by comparative 16s rrna and dnak sequence analyses. two groups of related species were identified by neighbor-joining and maximum-parsimony analysis. one group consisted of mesorhizobium loti and mesorhizobium ciceri, and the other group consisted of agrobacterium rhizogenes, rhizobium tropici, rhizobium etli, and rhizobium leguminosarum. although bootstrap support for the placement of t ...	2005	15746335