| phylogenetic and genetic relationships of mesorhizobium tianshanense and related rhizobia. | the genetic and phylogenetic relationships for strains of mesorhizobium tianshanense and its relatives were compared by an analysis of the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) of whole-cell proteins, dna-dna hybridization, and full 16s rrna gene sequencing. the strains of m. tianshanense formed a cluster which was distinct from those of other rhizobium species in the clustering analysis of sds-page. dna-dna relatedness between a-1bs (type strain of m. t ... | 1997 | 9226921 |
| genetic diversity of rhizobial symbionts isolated from legume species within the genera astragalus, oxytropis, and onobrychis. | the genetic diversity of 44 rhizobial isolates from astragalus, oxytropis, and onobrychis spp. originating from different geographic locations was evaluated by mapped restriction site polymorphism (mrsp) analysis of 16s rrna genes and by pcr dna fingerprinting with repetitive sequences (rep-pcr). a comparison of tree topologies of reference strains constructed with data obtained by mrsp and by 16s rrna gene sequence analyses showed that the topologies were in good agreement, indicating that the ... | 1997 | 9406393 |
| three phylogenetic groups of noda and nifh genes in sinorhizobium and mesorhizobium isolates from leguminous trees growing in africa and latin america. | the diversity and phylogeny of noda and nifh genes were studied by using 52 rhizobial isolates from acacia senegal, prosopis chilensis, and related leguminous trees growing in africa and latin america. all of the strains had similar host ranges and belonged to the genera sinorhizobium and mesorhizobium, as previously determined by 16s rrna gene sequence analysis. the restriction patterns and a sequence analysis of the noda and nifh genes divided the strains into the following three distinct grou ... | 1998 | 9464375 |
| characterization of aquamicrobium defluvii gen. nov. sp. nov., a thiophene-2-carboxylate-metabolizing bacterium from activated sludge. | a gram-negative bacterium was isolated from activated sewage sludge with thiophene-2-carboxylate as the sole source of carbon and with nitrate as an electron acceptor. the isolate, strain nkk, was a motile, oxidase- and catalase-positive, rod-like bacterium with a g+c content of 61.7 mol%. besides nitrate, oxygen could serve as a terminal electron acceptor. among many carbon sources tested, only a few sugars, fatty acids, and thiophene-2-carboxylate supported growth. other heterocyclic compounds ... | 1998 | 9531630 |
| evolution of rhizobia by acquisition of a 500-kb symbiosis island that integrates into a phe-trna gene. | nodulation and nitrogen fixation genes of mesorhizobium loti are encoded on the chromosome of the bacterium. nevertheless, there is strong evidence that these genes can be transferred from an inoculant strain to nonsymbiotic mesorhizobia in the field environment. here we report that the chromosomal symbiotic element of m. loti strain icmp3153 is transmissible in laboratory matings to at least three genomic species of nonsymbiotic mesorhizobia. the element is 500 kb in size, integrates into a phe ... | 1998 | 9560243 |
| novel branched nod factor structure results from alpha-(1-->3) fucosyl transferase activity: the major lipo-chitin oligosaccharides from mesorhizobium loti strain nzp2213 bear an alpha-(1-->3) fucosyl substituent on a nonterminal backbone residue. | mesorhizobium loti has been described as a microsymbiont of plants of the genus lotus. lipo-chitin oligosaccharides (lcos), or nod factors, produced by several representative m. loti strains all have similar structures. using fast-atom-bombardment tandem mass spectrometry and nmr spectroscopy, we have now examined the lcos from the type strain nzp2213 and observed a much greater variety of structures than has been described for the strains of m.loti studied previously. interestingly, we have ide ... | 1998 | 9636046 |
| biodiversity of rhizobia isolated from a wide range of forest legumes in brazil. | tropical forests have a high diversity of plant species; are they associated with a correspondingly rich microbial flora? we addressed this question by examining the symbiotic rhizobium bacteria that nodulate a diverse pool of forest legume species in brazil. the 44 strains studied had been isolated from 29 legume tree species representing 13 tribes including all three subfamilies of the leguminosae, and were chosen to represent major groups from a larger sample that had previously been characte ... | 1998 | 9691490 |
| tricarboxylic acid cycle and anaplerotic enzymes in rhizobia. | rhizobia are a diverse group of gram-negative bacteria comprised of the genera rhizobium, bradyrhizobium, mesorhizobium, sinorhizobium and azorhizobium. a unifying characteristic of the rhizobia is their capacity to reduce (fix) atmospheric nitrogen in symbiotic association with a compatible plant host. symbiotic nitrogen fixation requires a substantial input of energy from the rhizobial symbiont. this review focuses on recent studies of rhizobial carbon metabolism which have demonstrated the im ... | 1998 | 9729766 |
| characterization of tropical tree rhizobia and description of mesorhizobium plurifarium sp. nov. | a collection of strains isolated from root nodules of acacia species in senegal was analysed previously by electrophoresis of total cell protein, auxanographic tests, rrna-dna hydridization, 16s rrna gene sequencing, dna base composition and dna-dna hybridization [de lajudie, p., willems, a., pot, b. & 7 other authors (1994). int j syst bacteriol 44, 715-733]. strains from acacia were shown to belong to two groups, sinorhizobium terangae, and a so-called gel electrophoretic cluster u, which also ... | 1998 | 9731275 |
| molecular diversity of rhizobia occurring on native shrubby legumes in southeastern australia | the structure of rhizobial communities nodulating native shrubby legumes in open eucalypt forest of southeastern australia was investigated by a molecular approach. twenty-one genomic species were characterized by small-subunit ribosomal dna pcr-restriction fragment length polymorphism and phylogenetic analyses, among 745 rhizobial strains isolated from nodules sampled on 32 different legume host species at 12 sites. among these rhizobial genomic species, 16 belonged to the bradyrhizobium subgro ... | 1998 | 9758831 |
| symbiotic mutants deficient in nodule establishment identified after t-dna transformation of lotus japonicus. | nitrogen-fixing root nodules develop on legumes as a result of an interaction between host plants and soil bacteria collectively referred to as rhizobia. the organogenic process resulting in nodule development is triggered by the bacterial microsymbiont, but genetically controlled by the host plant genome. using t-dna insertion as a tool to identify novel plant genes that regulate nodule ontogeny, we have identified two putatively tagged symbiotic loci, ljsym8 and ljsym13, in the diploid legume ... | 1998 | 9790598 |
| allorhizobium undicola gen. nov., sp. nov., nitrogen-fixing bacteria that efficiently nodulate neptunia natans in senegal. | a group of nodule isolates from neptunia natans, an indigenous stemnodulated tropical legume found in waterlogged areas of senegal, was studied. polyphasic taxonomy was performed, including sds-page of total proteins, auxanography using api galleries, host-plant specificity, pcr-rflp of the internal transcribed spacer region between the 16s and the 23s rrna coding genes, 16s rrna gene sequencing and dna-dna hybridization. it was demonstrated that this group is phenotypically and phylogenetically ... | 1998 | 9828428 |
| diversity of rhizobia associated with amorpha fruticosa isolated from chinese soils and description of mesorhizobium amorphae sp. nov. | fifty-five chinese isolates from nodules of amorpha fruticosa were characterized and compared with the type strains of the species and genera of bacteria which form nitrogen-fixing symbioses with leguminous host plants. a polyphasic approach, which included rflp of pcr-amplified 16s rrna genes, multilocus enzyme electrophoresis (mlee), dna-dna hybridization, 16s rrna gene sequencing, electrophoretic plasmid profiles, cross-nodulation and a phenotypic study, was used in the comparative analysis. ... | 1999 | 10028247 |
| chitin oligosaccharide synthesis by rhizobia and zebrafish embryos starts by glycosyl transfer to o4 of the reducing-terminal residue. | lipochitin oligosaccharides are organogenesis-inducing signal molecules produced by rhizobia to establish the formation of nitrogen-fixing root nodules in leguminous plants. chitin oligosaccharide biosynthesis by the mesorhizobium loti nodulation protein nodc was studied in vitro using membrane fractions of an escherichia coli strain expressing the cloned m. loti nodc gene. the results indicate that prenylpyrophosphate-linked intermediates are not involved in the chitin oligosaccharide synthesis ... | 1999 | 10194317 |
| occurrence of choline and glycine betaine uptake and metabolism in the family rhizobiaceae and their roles in osmoprotection | the role of glycine betaine and choline in osmoprotection of various rhizobium, sinorhizobium, mesorhizobium, agrobacterium, and bradyrhizobium reference strains which display a large variation in salt tolerance was investigated. when externally provided, both compounds enhanced the growth of rhizobium tropici, sinorhizobium meliloti, sinorhizobium fredii, rhizobium galegae, agrobacterium tumefaciens, mesorhizobium loti, and mesorhizobium huakuii, demonstrating their utilization as osmoprotectan ... | 1999 | 10224003 |
| description of pseudaminobacter gen. nov. with two new species, pseudaminobacter salicylatoxidans sp. nov. and pseudaminobacter defluvii sp. nov. | an aerobic bacterium, strain bn12t, which degrades substituted naphthalenesulfonates and substituted salicylates was isolated from a 6-aminonaphthalene-2-sulfonate-degrading microbial consortium originating from the river elbe, germany. chemotaxonomic investigations of quinones, polyamines and polar lipids allowed allocation of this strain to the alpha-subclass of the proteobacteria and revealed similarity to species of the genera aminobacter, chelatobacter and mesorhizobium. this was confirmed ... | 1999 | 10319515 |
| comparison of the evolutionary dynamics of symbiotic and housekeeping loci: a case for the genetic coherence of rhizobial lineages. | in prokaryotes, lateral gene transfer across chromosomal lineages may be mediated by plasmids, phages, transposable elements, and other accessory dna elements. however, the importance of such transfer and the evolutionary forces that may restrict gene exchange remain largely unexplored in native settings. in this study, tests of phylogenetic congruence are employed to explore the range of horizontal transfer of symbiotic (sym) loci among distinct chromosomal lineages of native rhizobia, the nitr ... | 1999 | 10331255 |
| cellular envelopes and tolerance to acid ph in mesorhizobium loti. | changes in the cell envelopes in response to acidity were studied in two strains of mesorhizobium loti differing in their tolerance to ph. when the less acid-tolerant strain ll22 was grown at ph 5.5, membrane phosphatidylglycerol decreased and phosphatidylcholine increased, compared with cells grown at ph 7.0. on the other hand, when the more acid-tolerant strain ll56 was grown at ph 5.5, phosphatidylglycerol, phosphatidylethanolamine, and lysophospholipid decreased 25%, 39%, and 51% respectivel ... | 1999 | 10341073 |
| defluvibacter lusatiae gen. nov., sp. nov., a new chlorohenol-degrading member of the alpha-2 subgroup of proteobacteria. | the two gram-negative bacterial strains s1 and s4 were isolated from activated sludge of an industrial waste water treatment plant and exhibited a stable capability to degrade 2,4-dichlorophenol, 4-chloro-2-methylphenol, 4-chlorophenol and phenol. the cells were short rods with a polar flagellum, being mesophilic, strictly aerobic, oxidase-positive, and chemoorganotrophic. they utilized a range of amino acids, but only a restricted number of carbohydrates. reassociation experiments with dna from ... | 1999 | 10390870 |
| characterization of bacteria isolated from wild legumes in the north-western regions of china. | nodule isolates from 11 species of wild legumes in north-western china were characterized by numerical taxonomy, pcr-based 16s rrna gene rflp and sequence analyses, dna-dna hybridization, restriction patterns of noddab and nifh genes, and symbiotic properties. based on the results of numerical taxonomy, most of the 35 new isolates were grouped into five clusters (clusters 7, 9, 12, 14 and 15). clusters 7 and 12 were identified as mesorhizobium amorphae and agrobacterium tumefaciens, respectively ... | 1999 | 10555327 |
| structure of the mesorhizobium huakuii and rhizobium galegae nod factors: a cluster of phylogenetically related legumes are nodulated by rhizobia producing nod factors with alpha,beta-unsaturated n-acyl substitutions. | rhizobia are symbiotic bacteria that synthesize lipochitooligosaccharide nod factors (nfs), which act as signal molecules in the nodulation of specific legume hosts. based on the structure of their n-acyl chain, nfs can be classified into two categories: (i) those that are acylated with fatty acids from the general lipid metabolism; and (ii) those (= alphau-nfs) that are acylated by specific alpha,beta-unsaturated fatty acids (containing carbonyl-conjugated unsaturation(s)). previous work has de ... | 1999 | 10564467 |
| biochemical controls of citrate synthase in chickpea bacteroids. | bacteroids formed by mesorhizobium ciceri cc 1192 in symbiosis with chickpea plants (cicer arietinum l.) contained a single form of citrate synthase [citrate oxaloacetate-lyase (coa-acetylating) enzyme; ec 4.1.3.7], which had the same electrophoretic mobility as the enzyme from the free-living cells. the citrate synthase from cc 1192 bacteroids had a native molecular mass of 228 +/- 32 kda and was activated by kcl, which also enhanced stability. double reciprocal plots of initial velocity agains ... | 2000 | 10648103 |
| the glutamine synthetases of rhizobia: phylogenetics and evolutionary implications. | glutamine synthetase exists in at least two related forms, gsi and gsii, the sequences of which have been used in evolutionary molecular clock studies. gsi has so far been found exclusively in bacteria, and gsii has been found predominantly in eukaryotes. to date, only a minority of bacteria, including rhizobia, have been shown to express both forms of gs. the sequences of equivalent internal fragments of the gsi and gsii genes for the type strains of 16 species of rhizobia have been determined ... | 2000 | 10677854 |
| nickel availability and hupsl activation by heterologous regulators limit symbiotic expression of the rhizobium leguminosarum bv. viciae hydrogenase system in hup(-) rhizobia. | a limited number of rhizobium and bradyrhizobium strains possess a hydrogen uptake (hup) system that recycles the hydrogen released from the nitrogen fixation process in legume nodules. to extend this ability to rhizobia that nodulate agronomically important crops, we investigated factors that affect the expression of a cosmid-borne hup system from rhizobium leguminosarum bv. viciae upm791 in r. leguminosarum bv. viciae, rhizobium etli, mesorhizobium loti, and sinorhizobium meliloti hup(-) strai ... | 2000 | 10698755 |
| molecular basis of symbiotic promiscuity. | eukaryotes often form symbioses with microorganisms. among these, associations between plants and nitrogen-fixing bacteria are responsible for the nitrogen input into various ecological niches. plants of many different families have evolved the capacity to develop root or stem nodules with diverse genera of soil bacteria. of these, symbioses between legumes and rhizobia (azorhizobium, bradyrhizobium, mesorhizobium, and rhizobium) are the most important from an agricultural perspective. nitrogen- ... | 2000 | 10704479 |
| a new mesorhizobium loti hambi 1129 phage isolated from polish soil. | phage a1 isolated from the rhizosphere of lotus corniculatus was studied. it had a very narrow host range, as it was active only against mesorhizobium loti hambi 1129. phage a1 was classified as belonging to c bradley's group bacteriophages. the latent period of a1 was 120-130 min and a burst size 13-17 particles per cell. the nature of the phage receptor was examined. lipopolysaccharide from the phage-sensitive strain inactivated phage a1 in contrast to lps from the phage-resistant bacteria. pu ... | 2000 | 10706666 |
| a lotus japonicus nodulation system based on heterologous expression of the fucosyl transferase nodz and the acetyl transferase noil in rhizobium leguminosarum. | heterologous expression of nodz and noll proteins in rhizobium leguminosarum bv. viciae led to the production of acetyl fucosylated lipo-chitin oligosaccharides (lcos), indicating that the noll protein obtained from mesorhizobium loti functions as an acetyl transferase. we show that the noll-dependent acetylation is specific for the fucosyl penta-n-acetylglucosamine species. in addition, the noll protein caused elevated production of lcos. efficient nodulation of lotus japonicus by the nodz/noll ... | 2000 | 10755312 |
| differentiation of o-acetyl and o-carbamoyl esters of n-acetyl-glucosamine by decomposition of their oxonium ions. application to the structure of the nonreducing terminal residue of nod factors. | nod factors are substituted n-acyl chito-oligomers secreted by plant symbiotic bacteria of the rhizobium family. substitutions on the oligosaccharide core specify their recognition by host plants. a method using tandem mass spectrometry is proposed to locate the o-acetyl and o-carbamoyl substituents on the nonreducing terminal residue of the chito-oligomers. as model compounds, all the positional isomers of monoacetyl and monocarbamoyl esters of 1-o-methyl-n-acetyl-alpha-d-glucosamine were synth ... | 2000 | 10757166 |
| analysis of cellular fatty acids and phenotypic relationships of agrobacterium, bradyrhizobium, mesorhizobium, rhizobium and sinorhizobium species using the sherlock microbial identification system. | previous studies have demonstrated that cellular fatty acid analysis is a useful tool for identifying unknown strains of rhizobia and establishing taxonomic relationships between the species. in this study, the fatty acid profiles of over 600 strains belonging to the genera agrobacterium, bradyrhizobium, mesorhizobium, rhizobium and sinorhizobium were evaluated using the gaschromatography-based sherlock microbial identification system (mis). data collected with the mis showed that the three phyl ... | 2000 | 10758890 |
| mesorhizobium loti increases root-specific expression of a calcium-binding protein homologue identified by promoter tagging in lotus japonicus. | a promoter tagging program in the legume lotus japonicus was initiated to identify plant genes involved in the nitrogen-fixing symbiosis between legumes and rhizobia. seven transformed plant lines expressing the promoterless reporter gene uida (beta-glucuronidase; gus) specifically in roots and/or nodules were identified. four of these expressed gus in the roots only after inoculation with nodule-forming mesorhizobium loti. in one line (t90), gus activity was found in the root epidermis, includi ... | 2000 | 10830260 |
| numerical analysis of astragalus cicer microsymbionts. | thirty-seven rhizobium strains, isolated from root nodules of astragalus cicer (l.) (cicer milkvetch) deriving from different geographic regions, were compared with the representative strains of the known rhizobial species and genera by numerical analysis of phenotypic characteristics. our results indicated that astragalus cicer rhizobia were related to the bacteria of mesorhizobium species and formed two major phena. one phenon, localized on mesorhizobium loti branch, contained strains from pol ... | 2000 | 10856381 |
| the common nodulation genes of astragalus sinicus rhizobia are conserved despite chromosomal diversity. | the nodulation genes of mesorhizobium sp. (astragalus sinicus) strain 7653r were cloned by functional complementation of sinorhizobium meliloti nod mutants. the common nod genes, nodd, noda, and nodbc, were identified by heterologous hybridization and sequence analysis. the noda gene was found to be separated from nodbc by approximately 22 kb and was divergently transcribed. the 2. 0-kb noddbc region was amplified by pcr from 24 rhizobial strains nodulating a. sinicus, which represented differen ... | 2000 | 10877796 |
| denitrification with methane as electron donor in oxygen-limited bioreactors. | the microbial population from a reactor using methane as electron donor for denitrification under microaerophilic conditions was analyzed. high numbers of aerobic methanotrophic bacteria (3 10(7) cells/ml) and high numbers of acetate-utilizing denitrifying bacteria (2 10(7) cells/ml) were detected, but only very low numbers of methanol-degrading denitrifying bacteria (4 10(4) cells/ml) were counted. two abundant acetate-degrading denitrifiers were isolated which, based on 16s rrna analysis, were ... | 2000 | 10919339 |
| isolation and characterization of diverse halobenzoate-degrading denitrifying bacteria from soils and sediments. | denitrifying bacteria capable of degrading halobenzoates were isolated from various geographical and ecological sites. the strains were isolated after initial enrichment on one of the monofluoro-, monochloro-, or monobromo-benzoate isomers with nitrate as an electron acceptor, yielding a total of 33 strains isolated from the different halobenzoate-utilizing enrichment cultures. each isolate could grow on the selected halobenzoate with nitrate as the terminal electron acceptor. the isolates obtai ... | 2000 | 10919805 |
| short root mutant of lotus japonicus with a dramatically altered symbiotic phenotype. | legume plants carefully control the extent of nodulation in response to rhizobial infection. to examine the mechanism underlying this process we conducted a detailed analysis of the lotus japonicus hypernodulating mutants, har1-1, 2 and 3 that define a new locus, hypernodulation aberrant root formation (har1), involved in root and symbiotic development. mutations in the har1 locus alter root architecture by inhibiting root elongation, diminishing root diameter and stimulating lateral root initia ... | 2000 | 10929105 |
| occurrence and taxonomic significance of oxo-fatty acids in lipopolysaccharides from members of mesorhizobium. | lipopolysaccharides (lpss) isolated from seven strains of mesorhizobium were studied for the presence of fatty acids with particular attention for 27-oxooctacosanoic acid and 4-oxo fatty acids. the lpss from all analysed strains contained various amounts of 27-oxo-28:0 and all of them, with the exception of mesorhizobium tianshanense, contained also 4-oxo fatty acids (4-oxo-20:0, 4-oxo-i-21:0, 4-oxo-22:0). the group of amide-linked fatty acids consisted of a wide range of 3-hydroxylated and 4-ox ... | 2000 | 10930069 |
| isolation of two different phenotypes of mycorrhizal mutants in the model legume plant lotus japonicus after ems-treatment. | lotus japonicus has been proposed as a model plant for the molecular genetic study of plant-microbe interaction including mesorhizobium loti and arbuscular mycorrhizal (am) fungi. non-mycorrhizal mutants of lotus japonicus were screened from a collection of 12 mutants showing non-nodulating (nod-), ineffectively nodulating (fix-) and hypernodulating (nod++) phenotypes with monogenic recessive inheritance induced by ems (ethylmethane sulfonate) mutagenesis. three mycorrhizal mutant lines showing ... | 2000 | 10945342 |
| lotus japonicus contains two distinct enod40 genes that are expressed in symbiotic, nonsymbiotic, and embryonic tissues. | enod40, an early nodulin gene, has been postulated to play a significant role in legume root nodule ontogenesis. we have isolated two distinct enod40 genes from lotus japonicus. the transcribed regions of the two enod40 genes share 65% homology, while the two promoters showed no significant homology. both transcripts encode a putative dodecapeptide similar to that identified in other legumes forming determinate nodules. both enod40 genes are coordinately expressed following inoculation of roots ... | 2000 | 10975655 |
| sesbania herbacea-rhizobium huautlense nodulation in flooded soils and comparative characterization of s. herbacea-nodulating rhizobia in different environments. | the nodulation of s. herbacea was compared under flooded and non-flooded conditions in two different soils. one soil was from a flooded field in sierra de huautla, the native habitat of this legume, while the other soil was from a well-drained field in cuernavaca, where rhizobia were found to nodulate the introduced s. herbacea plants. nodulation of the plants was completely eliminated by flooding in the cuernavaca soil, whereas nodules were obtained in the same soil under non-flooded conditions ... | 2000 | 10977874 |
| generation of new hydrogen-recycling rhizobiaceae strains by introduction of a novel hup minitransposon. | hydrogen evolution by nitrogenase is a source of inefficiency for the nitrogen fixation process by the rhizobium-legume symbiosis. to develop a strategy to generate rhizobial strains with h(2)-recycling ability, we have constructed a tn5 derivative minitransposon (tnhb100) that contains the ca. 18-kb h(2) uptake (hup) gene cluster from rhizobium leguminosarum bv. viciae upm791. bacteroids from tnhb100-containing strains of r. leguminosarum bv. viciae pre, bradyrhizobium japonicum, r. etli, and m ... | 2000 | 11010872 |
| functional analysis of chimeras derived from the sinorhizobium meliloti and mesorhizobium loti nodc genes identifies regions controlling chitin oligosaccharide chain length. | the rhizobial nodulation gene nodc encodes an n-acetylglucosaminyltransferase that is responsible for the synthesis of chitin oligosaccharides. these oligosaccharides are precursors for the synthesis of the lipo-chitin oligosaccharides that induce cell division and differentiation during the development of nitrogen-fixing root nodules in leguminous plants. the nodc proteins of mesorhizobium loti and sinorizobium meliloti yield chitinpentaose and chitintetraose as their main products, respectivel ... | 2000 | 11016835 |
| the lotus japonicus ljsym4 gene is required for the successful symbiotic infection of root epidermal cells. | the role of the lotus japonicus ljsym4 gene during the symbiotic interaction with mesorhizobium loti and arbuscular mycorrhizal (am) fungi was analyzed with two mutant alleles conferring phenotypes of different strength. ljsym4-1 and ljsym4-2 mutants do not form nodules with m. loti. normal root hair curling and infection threads are not observed, while a nodc-dependent deformation of root hair tips indicates that nodulation factors are still perceived by ljsym4 mutants. fungal infection attempt ... | 2000 | 11043472 |
| bradyrhizobium sp. strains that nodulate the leguminous tree acacia albida produce fucosylated and partially sulfated nod factors. | we determined the structures of nod factors produced by six different bradyrhizobium sp. strains nodulating the legume tree acacia albida (syn. faidherbia albida). compounds from all strains were found to be similar, i.e., o-carbamoylated and substituted by an often sulfated methyl fucose and different from compounds produced by rhizobium-mesorhizobium-sinorhizobium strains nodulating other species of the acaciae tribe. | 2000 | 11055966 |
| phylogenetic diversity of rhizobial strains nodulating robinia pseudoacacia l. | lack of knowledge exists regarding the diversity of rhizobial strains nodulating black locust (robinia pseudoacacia l.), which is a neophytic tree species widely distributed in europe. seventeen rhizobial strains isolated from nodules of black locust at a german location were examined by phenotypic characterization and 16s rdna analysis. the isolates were classified in nine 16s rdna genotypes using a set of seven endonucleases. based on rflp analysis and sequencing, the strains were shown to bel ... | 2000 | 11065378 |
| sequence diversity of the plasmid replication gene repc in the rhizobiaceae. | the repabc operon is essential for stable maintenance of some rhizobiaceae plasmids and of ptav320 from paracoccus versutus. these plasmids are the largest described family of homologous, yet compatible replicons. the repc gene is essential for plasmid replication, and previous work identified four distinct sequence groups (repc1, repc2, repc3, and repc4) that appear to define different compatibility classes. probes for these different groups were used to characterize plasmids in rhizobium legum ... | 2000 | 11078647 |
| the involvement of a cysteine proteinase in the nodule development in chinese milk vetch infected with mesorhizobium huakuii subsp. rengei. | cys proteinases play important roles in plant cell development and senescence. a cdna, asnodf32, obtained by differential screening of a nodule cdna library of the leguminous plant chinese milk vetch (astragalus sinicus), represents a nodule-specific cys proteinase similar to that reported for the actinorhizal alnus glutinosa-flankia symbiosis. a characteristic feature of this proteinase is the presence of a putative vacuolar targetting signal, lqda, within its propeptide. expression of the asno ... | 2000 | 11080286 |
| structure of the o-specific polysaccharide of mesorhizobium huakuii ifo15243t. | the structure of the o-specific polysaccharide isolated by mild acid hydrolysis of the lipopolysaccharide of mesorhizobium huakuii ifo15243t was studied using methylation analysis and various one- and two-dimensional 1h and 13c nmr experiments. the o-antigen polysaccharide was found to be linear polymer constituted by a trisaccharide repeating unit of the following structure: --> 2)-alpha-l-6dtalp-(1 --> 3)-alpha-l-6dtalp-(1 --> 2)-alpha-l-rhap-(1 -->. | 2000 | 11117330 |
| cytokine inducing activities of rhizobial and mesorhizobial lipopolysaccharides of different lethal toxicity. | the lethality and cytokines-inducing activity of lipopolysaccharides (lps) obtained from nodulating bacteria, rhizobium leguminosarum and mesorhizobium loti, were compared to those of salmonella typhimurium lps. the activity of r. leguminosarum lps was almost comparable to salmonella endotoxin in terms of lethality, limulus lysate gelating activity and in vivo tumor necrosis factor-alpha (tnf-alpha), interleukin-1beta (il-1beta), interleukin-6 (il-6) and interferon-gamma (ifn-gamma) induction ca ... | 2000 | 11131156 |
| [sequencing the 16s rdna of representative strain of new rhizobial group and determining of its phylogenetic relationship]. | the full-length 16s rdna sequence of representative strain sh2672 were sequenced by the dideoxy-mediated chain-termination method. this sequence was compared with that of type strains of all known rhizobia and related bacteria. an unrooted phylogenetic tree was produced. in this tree, strain sh2672, mesorhizobium loti, m. huakuii, m. tianshanense, m. mediterraneum, and m. ciceri constituted a branch. within this branch, the similarity values of 16s rdna sequences between strain sh2672 and m. lot ... | 1997 | 11189370 |
| lotus japonicus forms early senescent root nodules with rhizobium etli. | mesorhizobium loti and rhizobium etli are microsymbionts of the lotus and phaseolus spp., respectively, and secrete essentially the same nod factors. lotus japonicus efficiently formed root nodules with r. etli ce3, irrespective of the presence or absence of a flavonoid-independent transcription activator nodd gene. on a nitrogen-free medium, however, the host plant inoculated with r. etli showed a severe nitrogen deficiency symptom. initially, the nodules formed with r. etli were pale pink and ... | 2001 | 11204780 |
| complete genome structure of the nitrogen-fixing symbiotic bacterium mesorhizobium loti. | the complete nucleotide sequence of the genome of a symbiotic bacterium mesorhizobium loti strain maff303099 was determined. the genome of m. loti consisted of a single chromosome (7,036,071 bp) and two plasmids, designated as pmla (351,911 bp) and pmlb (208, 315 bp). the chromosome comprises 6752 potential protein-coding genes, two sets of rrna genes and 50 trna genes representing 47 trna species. fifty-four percent of the potential protein genes showed sequence similarity to genes of known fun ... | 2000 | 11214968 |
| complete genome structure of the nitrogen-fixing symbiotic bacterium mesorhizobium loti (supplement). | | 2000 | 11214974 |
| classification of rhizobia based on nodc and nifh gene analysis reveals a close phylogenetic relationship among phaseolus vulgaris symbionts. | the nodc and nifh genes were characterized in a collection of 83 rhizobial strains which represented 23 recognized species distributed in the genera rhizobium, sinorhizobium, mesorhizobium and bradyrhizobium, as well as unclassified rhizobia from various host legumes. conserved primers were designed from available nucleotide sequences and were able to amplify nodc and nifh fragments of about 930 bp and 780 bp, respectively, from most of the strains investigated. rflp analysis of the pcr products ... | 2001 | 11283294 |
| effects of salinity on protein and lipopolysaccharide pattern in a salt-tolerant strain of mesorhizobium ciceri. | to characterize the physiological and metabolic responses of mesorhizobium ciceri strain ch-191 to salt stress, investigating the changes induced by salinity in protein and lipopolysaccharide profiles, as well as determining the accumulation of amino acids, glutamate and proline. | 2001 | 11298245 |
| human alpha3-fucosyltransferases convert chitin oligosaccharides to products containing a glcnacbeta1-4(fucalpha1-3)glcnacbeta1-4r determinant at the nonreducing terminus. | human alpha3-fucosyltransferases (fuc-ts) are known to convert n-acetyllactosamine to galbeta1-4(fucalpha1-3)glcnac (lewis x antigen); some of them transfer fucose also to galnacbeta1-4glcnac, generating galnacbeta1-4(fucalpha1-3)glcnac determinants. here, we report that recombinant forms of fuc-tv and fuc-tvi as well as fuc-ts of human milk converted chitin oligosaccharides of 2-4 glcnac units efficiently to products containing a glcnacbeta1-4(fucalpha1-3)glcnacbeta1-4r determinant at the nonre ... | 2001 | 11320059 |
| the bio operon on the acquired symbiosis island of mesorhizobium sp. strain r7a includes a novel gene involved in pimeloyl-coa synthesis. | the symbiosis island of mesorhizobium sp. strain r7a is a 500 kb chromosomal genetic element that upon transfer converts nonsymbiotic mesorhizobia to symbionts able to nodulate and fix nitrogen with lotus corniculatus. four genomic species of nonsymbiotic mesorhizobia have been isolated. all were auxotrophic for thiamin and biotin and three were auxotrophic for nicotinate, whereas derivatives of the strains containing the symbiosis island were prototrophic for all three vitamins. in this work, a ... | 2001 | 11320134 |
| dna synthesis and fragmentation in bacteroids during astragalus sinicus root nodule development. | histo- and cytochemical techniques were used to study the dna replication and fragmentation patterns in bacteroids formed by mesorhizobium huakuii subsp. rengei in nodules of astragalus sinicus. dna replication was detected by the incorporation of 5-bromo deoxy-uridine. signals denoting dna synthesis were observed in plant nuclei within the nodule meristem and in bacteroids near the meristem. the tunel (tdt-mediated dutp nick-end labeling) assay was used to measure dna fragmentation. in nutrient ... | 2001 | 11330661 |
| rhizobial nodl o-acetyl transferase and nods n-methyl transferase functionally interfere in production of modified nod factors. | the products of the rhizobial nodulation genes are involved in the biosynthesis of lipochitin oligosaccharides (lcos), which are host-specific signal molecules required for nodule formation. the presence of an o-acetyl group on c-6 of the nonreducing n-acetylglucosamine residue of lcos is due to the enzymatic activity of nodl. here we show that transfer of the nodl gene into four rhizobial species that all normally produce lcos that are not modified on c-6 of the nonreducing terminal residue res ... | 2001 | 11344149 |
| ribotyping of rhizobia nodulating acacia mangium and paraserianthes falcataria from different geographical areas in indonesia using pcr-rflp-sscp (prs) and sequencing. | acacia mangium and paraserianthes falcataria are leguminous tree species widely grown for timber in indonesia and other tropical countries, yet little is known about the identity of their rhizobial symbionts. polymerase chain reaction-restriction fragment length polymorphism-single-strand conformational polymorphism (prs) analysis of the 16s rrna gene was used along with sequencing to assess the diversity of 57 rhizobia isolated from nodules of a. mangium and p. falctaria in indonesia. in total, ... | 2001 | 11359513 |
| unusual methyl-branched alpha,beta-unsaturated acyl chain substitutions in the nod factors of an arctic rhizobium, mesorhizobium sp. strain n33 (oxytropis arctobia). | mesorhizobium sp. strain n33 (oxytropis arctobia), a rhizobial strain isolated in arctic canada, is able to fix nitrogen at very low temperatures in association with a few arctic legume species belonging to the genera astragalus, onobrychis, and oxytropis. using mass spectrometry and nuclear magnetic resonance spectroscopy, we have determined the structure of n33 nod factors, which are major determinants of nodulation. they are pentameric lipochito-oligosaccharides 6-o sulfated at the reducing e ... | 2001 | 11371536 |
| mesorhizobium chacoense sp. nov., a novel species that nodulates prosopis alba in the chaco arido region (argentina). | low-molecular-weight rna analysis was performed for the identification and classification of 20 argentinian strains isolated from the root nodules of prosopis alba. sds-page of total cellular proteins, determination of the dna base composition, dna-dna reassociation experiments and physiological and biochemical tests were also carried out for these strains and the whole 16s rrna gene was sequenced from one of the strains, strain lmg 19008t. results of the genotypic and phenotypic characterizatio ... | 2001 | 11411668 |
| responses of a model legume lotus japonicus to lipochitin oligosaccharide nodulation factors purified from mesorhizobium loti jrl501. | lotus japonicus has been proposed as a model legume for molecular genetic studies of symbiotic plant-microbe interactions leading to the fixation of atmospheric nitrogen. lipochitin oligosaccharides (lcos), or nod factors, were isolated from the culture of mesorhizobium loti strain jrl501 (maff303099), an efficient microsymbiont of l. japonicus b-129 cv. gifu. high-performance liquid chromatography and mass spectrometric analyses allowed us to identify at least five different structures of lcos ... | 2001 | 11437258 |
| an ochrobactrum anthropi gene conferring paraquat resistance to the heterologous host escherichia coli. | a new gene, pqra, conferring paraquat resistance to the heterologous host escherichia coli, from a chromosomal dna library of ochrobactrum anthropi jw2, was cloned and analyzed. cells of e. coli transformed with a plasmid carrying the pqra gene showed elevated resistance to paraquat, but not to hydrogen peroxide. the predicted amino acid sequence of the pqra polypeptide showed 71% identity with mll7495 hypothetical membrane protein in mesorhizobium loti, 49% identity with pa2269 protein in pseud ... | 2001 | 11467833 |
| rose elements occur in disparate rhizobia and are functionally interchangeable between species. | expression of at least ten genes in bradyrhizobium japonicum, seven of which code for small heat shock proteins (shsps), is under the control of rose (repression of heat shock gene expression). this negatively cis-acting dna element confers temperature control to a sigma(70)-type promoter. here, we show that rose elements are not restricted to b. japonicum but are also present in bradyrhizobium sp. (parasponia), rhizobium sp. strain ngr234 and mesorhizobium loti. an overall alignment of all rose ... | 2001 | 11479702 |
| ismh2, a novel insertion sequence-like element associated with nifa from mesorhizobium huakuii. | sequence analysis of the nifa gene, including its 5' flanking region, of mesorhizobium huakuii revealed the presence of a novel is-like element called ismh2. it is 828 bp in length and possesses two imperfect terminal inverted repeats of 14 bp with only one mismatch. the putative transposase encoded by ismh2 is composed of 204 amino acids. in comparison with other insertion sequences ismh2 likely belongs to the is6 family. multiple copies of ismh2 were detected in the genome of m. huakuii 159 by ... | 2001 | 11535031 |
| rhizobia from wild legumes: diversity, taxonomy, ecology, nitrogen fixation and biotechnology. | wild legumes (herb or tree) are widely distributed in arid regions and actively contribute to soil fertility in these environments. the n2-fixing activity and tolerance to drastic conditions may be higher in wild legumes than in crop legumes. the wild legumes in arid zones harbor diverse and promiscuous rhizobia in their root-nodules. specificity existed only in few rhizobia from wild legumes, however, the majority of them are with wide host range. based on phenotypic characteristics and molecul ... | 2001 | 11566386 |
| genetic diversity of rhizobia isolated from astragalus adsurgens growing in different geographical regions of china. | the genetic diversity among 95 isolates from astragalus adsurgens was investigated using molecular biological methods. all of the isolates and 24 reference strains could be differentiated by aflp, rep-, eric- and box-pcr fingerprinting analysis. by cluster analysis of the data, 31 aflp and 38 rep-pcr genomic groups were delineated, indicating considerable genetic diversity among the isolates. fifty-four representative strains were further analyzed by rflp of pcr-amplified 16s and 23s rdna, revea ... | 2001 | 11566387 |
| the diversity of rhizobia nodulating beans in northwest argentina as a source of more efficient inoculant strains. | the common bean (phaseolus vulgaris l.) is cultivated widely in central and south america and particularly in the northwest of argentina. in order to describe the diversity of the common bean nodulating rhizobial population from the bean producing area in northwest argentina (nwa), a collection of about 400 isolates of common beans recovered from nodules and soil samples from nwa were characterized by using nifh-pcr, analysis of genes coding for 16s rrna and nodc, and rep-fingerprinting, respect ... | 2001 | 11566389 |
| a glutathione-dependent formaldehyde-activating enzyme (gfa) from paracoccus denitrificans detected and purified via two-dimensional proton exchange nmr spectroscopy. | the formation of s-hydroxymethylglutathione from formaldehyde and glutathione is a central reaction in the consumption of the cytotoxin formaldehyde in some methylotrophic bacteria as well as in many other organisms. we describe here the discovery of an enzyme from paracoccus denitrificans that accelerates this spontaneous condensation reaction. the rates of s-hydroxymethylglutathione formation and cleavage were determined under equilibrium conditions via two-dimensional proton exchange nmr spec ... | 2002 | 11741920 |
| phylogenetic relationships of three bacterial strains isolated from the pasture legume biserrula pelecinus l. | three bacterial strains (wsm 1283, wsm 1284, wsm 1497) isolated from root nodules of the pasture legume biserrula pelecinus l. growing in morocco, italy and greece, respectively, were studied in order to determine their phylogenetic relationship to the other members of the family rhizobiaceae. a polyphasic approach, which included analyses of morphological and physiological characteristics, plasmid profiles, symbiotic performance and 16s rrna gene sequencing, indicated that these strains belong ... | 2001 | 11760938 |
| phylogenies of atpd and reca support the small subunit rrna-based classification of rhizobia. | the current classification of the rhizobia (root-nodule symbionts) assigns them to six genera. it is strongly influenced by the small subunit (16s, ssu) rrna molecular phylogeny, but such single-gene phylogenies may not reflect the evolution of the genome as a whole. to test this, parts of the atpd and reca genes have been sequenced for 25 type strains within the alpha-proteobacteria, representing species in rhizobium, sinorhizobium, mesorhizobium, bradyrhizobium, azorhizobium, agrobacterium, ph ... | 2001 | 11760945 |
| chitinolytic and cellulolytic pseudomonas sp. antagonistic to fungal pathogens enhances nodulation by mesorhizobium sp. cicer in chickpea. | pseudomonas strains isolated from the rhizosphere of chickpea (cicer arietinum l.) and green gram (vigna radiata l.) were screened for the production of chitinases and cellulases. five pseudomonas strains were found to produce appreciable amounts of both enzymes in culture-free supernatants and showed growth inhibition of the two fungi pythium aphanidermatum (oomycete) and rhizoctonia solani (basidiomycete) in plates on potato dextrose agar medium. the fungal growth inhibition was not correlated ... | 2001 | 11770853 |
| integrative genetic element that reverses the usual target gene orientation. | a genetic element integrating site specifically into a prokaryotic gene usually carries a copy of the 3' portion of that gene that restores the active gene even as the original is disrupted. a cryptic element in mesorhizobium loti instead carries a copy of the 5' end of the trna gene into which it integrated. this has implications for the evolution of new integrase-site combinations. | 2002 | 11790760 |
| classification of the caspase-hemoglobinase fold: detection of new families and implications for the origin of the eukaryotic separins. | a comprehensive sequence and structural comparative analysis of the caspase-hemoglobinase protein fold resulted in the delineation of the minimal structural core of the protease domain and the identification of numerous, previously undetected members, including a new protease family typified by the hetf protein from the cyanobacterium nostoc. the first bacterial homologs of legumains and hemoglobinases were also identified. most proteins containing this fold are known or predicted to be active p ... | 2002 | 11835511 |
| differences between subcultures of the mesorhizobium loti type strain from different culture collections. | because of differences in the reported 16s rrna gene sequence of the mesorhizobium loti type strain available from different culture collections, we collected different subcultures of this strain and compared them by 16s rdna sequencing, sds-page of whole-cell protein extracts and rapd-pcr. our results indicate that the 16s rdna sequence differences can be explained by the presence of two different organisms in one of the subcultures. in addition, even for subcultures of the type strain that had ... | 2001 | 11876362 |
| rhizobial acyl carrier proteins and their roles in the formation of bacterial cell-surface components that are required for the development of nitrogen-fixing root nodules on legume hosts. | acyl carrier protein (acp) of escherichia coli is a small acidic protein which functions as carrier of growing acyl chains during their biosynthesis and as donor of acyl chains during transfer to target molecules. this unique acp of e. coli is expressed constitutively. in more complex bacteria, multiple acps are present, indicating a channeling of pools of multi-carbon units into different biosynthetic routes. in rhizobia, for example, besides the constitutive acp (acpp) involved in the biosynth ... | 2002 | 11959430 |
| structural, functional, and evolutionary analysis of moez, a gene encoding an enzyme required for the synthesis of the pseudomonas metabolite, pyridine-2,6-bis(thiocarboxylic acid). | pyridine-2,6-bis(thiocarboxylic acid) (pdtc) is a small secreted metabolite that has a high affinity for transition metals, increases iron uptake efficiency by 20% in pseudomonas stutzeri, has the ability to reduce both soluble and mineral forms of iron, and has antimicrobial activity towards several species of bacteria. six genbank sequences code for proteins similar in structure to moez, a p. stutzeri protein necessary for the synthesis of pdtc. | 2002 | 11972321 |
| comparative sequence analysis of the symbiosis island of mesorhizobium loti strain r7a. | the mesorhizobium loti strain r7a symbiosis island is a 502-kb chromosomally integrated element which transfers to nonsymbiotic mesorhizobia in the environment, converting them to lotus symbionts. it integrates into a phenylalanine trna gene in a process mediated by a p4-type integrase encoded at the left end of the element. we have determined the nucleotide sequence of the island and compared its deduced genetic complement with that reported for the 611-kb putative symbiosis island of m. loti s ... | 2002 | 12003951 |
| analysis of mesorhizobium loti glycogen operon: effect of phosphoglucomutase (pgm) and glycogen synthase (g/ga) null mutants on nodulation of lotus tenuis. | the phosphoglucomutase (pgm) gene codes for a key enzyme required for the formation of udp-glucose and adp-glucose, the sugar donors for the biosynthesis of glucose containing polysaccharides. a mesorhizobium loti pgm null mutant obtained in this study contains an altered form of lipopolysaccharide (lps), lacks exopolysaccharide (eps), beta cyclic glucan, and glycogen and is unable to nodulate lotus tenuis. the nonnodulating phenotype of the pgm mutant was not due to the absence of glycogen, sin ... | 2002 | 12026175 |
| expressed sequence tags from roots and nodule primordia of lotus japonicus infected with mesorhizobium loti. | messenger rna from young lotus japonicus roots carrying root nodule primordia appearing after inoculation with mesorhizobium loti bacteria were used to construct a cdna expression library. single-pass sequencing employing colony-polymerase chain reaction (pcr) and analysis of pcr products established a total of 2,397 new expressed sequence tags (ests). we have putatively identified 1,236 known and 484 hypothetical proteins coded by the corresponding mrnas. the remaining cdnas are unknown (316) o ... | 2002 | 12026176 |
| enzymes of malate metabolism in mesorhizobium ciceri cc 1192. | electrophoretic studies were performed on enzymes concerned with the oxidation of malate in free-living and bacteroid cells of mesorhizobium ciceri cc 1192, which forms nitrogen-fixing symbioses with chickpea (cicer arietinum l.) plants. two malate dehydrogenases were detected in extracts from both types of cells in native polyacrylamide electrophoresis gels that were stained for enzyme activity. one band of malate dehydrogenase activity was stained only in the presence of nadp+, whereas the oth ... | 2002 | 12030699 |
| in silico sequence analysis of arylamine n-acetyltransferases: evidence for an absence of lateral gene transfer from bacteria to vertebrates and first description of paralogs in bacteria. | the arylamine n-acetyltransferases (nats) are xenobiotic-metabolizing enzymes responsible for the biotransformation of various arylamine and heterocyclic amines, including drugs and carcinogenic compounds. nat and nat-like genes have been identified in several vertebrate and eubacterial species. little is known about their evolutionary history, but the horizontal transfer of nat genes from bacteria to vertebrates was recently suggested [s. salzberg, o. white, j. peterson, j. eisen, science 292 ( ... | 2002 | 12054539 |
| the rhizobium etli cyac product: characterization of a novel adenylate cyclase class. | adenylate cyclases (acs) catalyze the formation of 3',5'-cyclic amp (camp) from atp. a novel ac-encoding gene, cyac, was isolated from rhizobium etli by phenotypic complementation of an escherichia coli cya mutant. the functionality of the cyac gene was corroborated by its ability to restore camp accumulation in an e. coli cya mutant. further, overexpression of a male::cyac fusion protein allowed the detection of significant ac activity levels in cell extracts of an e. coli cya mutant. cyac is u ... | 2002 | 12057950 |
| symbiotic and taxonomic diversity of rhizobia isolated from acacia tortilis subsp. raddiana in africa. | a collection of rhizobia isolated from acacia tortilis subsp. raddiana from various sites in the north and south of sahara was analyzed for their diversity at both taxonomic and symbiotic levels. on the basis of whole cell protein (sds-page) and 16s rdna sequence analysis, most of the strains were found to belong to the sinorhizobium and mesorhizobium genera where they may represent several different genospecies. despite their chromosomal diversity, most a. tortilis mesorhizobium and sinorhizobi ... | 2002 | 12086180 |
| contrasting nifd and ribosomal gene relationships among mesorhizobium from lotus oroboides in northern mexico. | pcr screens for length variation in a 5' portion of 23s ribosomal rna and in the 3' end of the 16s rrna-23s rrna internal transcribed spacer (its) region indicated that nodule bacteria from a mexican population of lotus oroboides were diverse on a local scale. three 23s rrna length variants and five its length variants were detected among the 22 isolates. sequencing of nearly full-length 16s rrna genes in three isolates indicated that they fell into the genus mesorhizobium, but comprised two dis ... | 2002 | 12086191 |
| purification, molecular cloning, and characterization of pyridoxine 4-oxidase from microbacterium luteolum. | pyridoxine 4-oxidase (ec 1.1.3.12, pn 4-oxidase), which catalyzes the oxidation of pn by oxygen or other hydrogen acceptors to form pyridoxal and hydrogen peroxide or reduced forms of the acceptors, respectively, was purified for the first time to homogeneity from microbacterium luteolum yk-1 (=aureobacterium luteolum yk-1). the purified enzyme required fad for its catalytic activity and stability. the enzyme was a monomeric protein with the subunit molecular mass of 53,000 +/- 1,000 da. pn was ... | 2002 | 12092811 |
| cloning and expression of the haloalkane dehalogenase gene dhma from mycobacterium avium n85 and preliminary characterization of dhma. | haloalkane dehalogenases are microbial enzymes that catalyze cleavage of the carbon-halogen bond by a hydrolytic mechanism. until recently, these enzymes have been isolated only from bacteria living in contaminated environments. in this report we describe cloning of the dehalogenase gene dhma from mycobacterium avium subsp. avium n85 isolated from swine mesenteric lymph nodes. the dhma gene has a g+c content of 68.21% and codes for a polypeptide that is 301 amino acids long and has a calculated ... | 2002 | 12147465 |
| comparative genomic analysis of plant-associated bacteria. | this review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. these are the genomes of agrobacterium tumefaciens, mesorhizobium loti, sinorhizobium meliloti, xanthomonas campestris pv campestris, xanthomonas axonopodis pv citri, xylella fastidiosa, and ralstonia solanacearum. genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. despite the recognized importance of the type iii secretion sy ... | 2002 | 12147758 |
| identification and characterization of a brucella abortus atp-binding cassette transporter homolog to rhizobium meliloti exsa and its role in virulence and protection in mice. | brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. the mechanism of virulence of brucella spp. is not fully understood yet. furthermore, genes that allow brucella to reach the intracellular niche and to interact with host cells need to be identified. using the genomic survey sequence (gss) approach, we identified the gene encoding an atp-binding cassette (abc) transporter of b. abortus strain s2308. the deduce ... | 2002 | 12183550 |
| mesorhizobium amorphae, a rhizobial species that nodulates amorpha fruticosa, is native to american soils. | amorpha fruticosa was inoculated with rhizosphere soil from iowa, usa, and 140 rhizobia isolated from root nodules were compared with mesorhizobium amorphae originating from chinese soils. pcr-rflp patterns of the 16s rrna gene from the isolates and from m. amorphaewere the same. all isolates had a symbiotic plasmid of the same size with a single nifhgene. dna:dna hybridization values, dna g+c content, and induced nod factor patterns also were similar. we concluded that the four genotypes distin ... | 2002 | 12209264 |
| phenotypic and molecular characterization of chickpea rhizobia isolated from different areas of morocco. | to determine the biodiversity of rhizobial strains nodulating cicer arietinum l. in representative soils from various areas of morocco. | 2002 | 12234335 |
| rapid colorimetric quantification of lipo-chitooligosaccharides from mesorhizobium loti and sinorhizobium meliloti. | nod factors are lipids with a chitinlike headgroup produced by gram-negative rhizobium bacteria. these lipo-chitooligosaccharides (lcos) are essential signaling molecules for accomplishing symbiosis between the bacteria and roots of legume plants. despite their important role in the rhizobium-legume interaction, no fast and sensitive nod factor quantification methods exist. here, we report two different quantification methods. the first is based on the enzymatic hydrolysis of nod factors to rele ... | 2002 | 12236592 |
| the brucella suis genome reveals fundamental similarities between animal and plant pathogens and symbionts. | the 3.31-mb genome sequence of the intracellular pathogen and potential bioterrorism agent, brucella suis, was determined. comparison of b. suis with brucella melitensis has defined a finite set of differences that could be responsible for the differences in virulence and host preference between these organisms, and indicates that phage have played a significant role in their divergence. analysis of the b. suis genome reveals transport and metabolic capabilities akin to soil/plant-associated bac ... | 2002 | 12271122 |
| a novel bioremediation system for heavy metals using the symbiosis between leguminous plant and genetically engineered rhizobia. | a novel plant-bacterial remediation system for heavy metals (hm) was developed by expression of tetrameric human metallothionein (mtl4) in mesorhizobium huakuii subsp. rengei b3, a strain which infects and forms nodules on a green manure, astragalus sinicus. the mtl4 gene was fused to the nifh and nolb promoters, which generated nodule- specific expression of the mtl4 gene. the expression analysis of the mtl4 gene was demonstrated in free-living cells in the presence of cd(2+) and cu(2+), under ... | 2002 | 12385715 |
| analysis of phospholipids and ornithine-containing lipids from mesorhizobium spp. | polar lipid compositions of seven strains belonging to the four species of the mesorhizobium genus were described. the lipid patterns of mesorhizobium strains were very similar. only quantitative differences were observed. diphosphatidylglycerol (dpg), phosphatidylglycerol (pg), phosphatidylethanolamine (pe), and phosphatidylcholine (pc) were found to be the major phospholipids of the analysed bacteria. in addition, two methylated derivatives of pe were observed: phosphatidyl-n,n-dimethylethanol ... | 2002 | 12421070 |
| what does a bacterial genome sequence represent? mis-assignment of maff 303099 to the genospecies mesorhizobium loti. | | 2002 | 12427922 |
| mutational and transcriptional analysis of the type iii secretion system of bradyrhizobium japonicum. | sequencing the symbiotic region of bradyrhizobium japonicum revealed a gene cluster (tts) encoding a type iii secretion system (ttss) that is similar to those found in mesorhizobium loti maff303099 and rhizobium strain ngr234. in addition to genes that are likely to encode structural core components of the ttss, the cluster contains several open reading frames that are found exclusively in rhizobia or that are specific to b. japonicum. depending on the host, mutations within this cluster affecte ... | 2002 | 12481995 |
| the glcb locus of rhizobium leguminosarum vf39 encodes an arabinose-inducible malate synthase. | in the course of a study conducted to isolate genes upregulated by plant cell wall sugars, we identified an arabinose-inducible locus from a transcriptional fusion library of rhizobium leguminosarum vf39, carrying random insertions of the lacz transposon tn5b22. sequence analysis of the locus disrupted by the transposon revealed a high similarity to uncharacterized malate synthase g genes from sinorhizobium meliloti, agrobacterium tumefaciens, and mesorhizobium loti. this enzyme catalyzes the co ... | 2002 | 12489782 |
| preincubation of mesorhizobium ciceri with flavonoids improves its nodule occupancy. | strains of m. ciceri, symbionts of chickpea (cicer arietinum) were incubated with the flavonoids naringenin, daidzein and quercetin which have earlier been reported as inducers and inhibitors of nodabc-lacz fusion of m. ciceri. preincubation of m. ciceri with naringenin and daidzein (100 nmol/l) for 1 d improved the competitive ability of the inoculated strain while preincubation with quercetin decreased the nodule occupancy of inoculated strain under sterile conditions. under non-sterile condit ... | 2002 | 12503401 |
| farnesyl diphosphate synthase gene of three phototrophic bacteria and its use as a phylogenetic marker. | farnesyl diphosphate (fpp) synthase is essential not only for phototrophic bacteria in carotenoid biosynthesis, but also for non-phototrophic bacteria in the biosynthesis of physiologically important compounds. the gene encoding fpp synthase was assessed as a molecular marker to investigate the intermingled relationship between the phototropic and non-phototropic bacteria in the alpha-proteobacteria based on 16s rrna analysis. the fpp synthase amino acid sequences from three phototropic bacteria ... | 2002 | 12508853 |