heavy metal resistance and genotypic analysis of metal resistance genes in gram-positive and gram-negative bacteria present in ni-rich serpentine soil and in the rhizosphere of alyssum murale.forty-six bacterial cultures, including one culture collection strain, thirty from the rhizosphere of alyssum murale and fifteen from ni-rich soil, were tested for their ability to tolerate arsenate, cadmium, chromium, zinc, mercury, lead, cobalt, copper, and nickel in their growth medium. the resistance patterns, expressed as minimum inhibitory concentrations, for all cultures to the nine different metal ions were surveyed by using the agar dilution method. a large number of the cultures were r ...200717276484
the nodulation of alfalfa by the acid-tolerant rhizobium sp. strain lpu83 does not require sulfated forms of lipochitooligosaccharide nodulation signals.the induction of root nodules by the majority of rhizobia has a strict requirement for the secretion of symbiosis-specific lipochitooligosaccharides (nodulation factors [nfs]). the nature of the chemical substitution on the nfs depends on the particular rhizobium and contributes to the host specificity imparted by the nfs. we present here a description of the genetic organization of the nod gene cluster and the characterization of the chemical structure of the nfs associated with the broad-host- ...201020971905
rhizobium mesosinicum sp. nov., isolated from root nodules of three different legumes.thirteen novel strains were isolated from root nodules of three different leguminous plants of the genera albizia, kummerowia and dalbergia grown in china. cells of these strains were gram-negative, strictly aerobic, non-spore-forming, motile rods. phylogenetic analysis of 16s rrna gene sequences revealed that they belong to the genus rhizobium. a representative strain, ccbau 25010t, showed 98.8% 16s rrna gene sequence similarity to its closest phylogenetic relative, rhizobium sullae is123t. the ...200919567587
characterization of phenol degradation by rhizobium sp. ccnwtb 701 isolated from astragalus chrysopteru in mining tailing screen high strength phenol degrading bacteria, we selected 108 rhizobial strains isolated from nodules of eight wild legumes species in the mining tailing region of shaanxi province, northwest of china, and cultivated them in a basal salt (bs) medium supplemented with different phenol concentrations as a sole carbon source. the results showed that some of the strains could use phenol as sole carbon source. in order to study the characteristics of phenol degradation, the strain ccnwtb701 isol ...200817624668
evolutionary genetics and biogeographic structure of rhizobium gallicum sensu lato, a widely distributed bacterial symbiont of diverse legumes.we used phylogenetic and population genetics approaches to evaluate the importance of the evolutionary forces on shaping the genetic structure of rhizobium gallicum and related species. we analysed 54 strains from several populations distributed in the northern hemisphere, using nucleotide sequences of three 'core' chromosomal genes (rrs, glnii and atpd) and two 'auxiliary' symbiotic genes (nifh and nodb) to elucidate the biogeographic history of the species and symbiotic ecotypes (biovarieties) ...200516262857
rhizobium yanglingense sp. nov., isolated from arid and semi-arid regions in china.a novel rhizobial group, cluster 9, defined in previous research [tan, z. y., wang, e. t., peng, g. x., zhu, m. e., martinez-romero, e. & chen, w. x. (1999). int j syst bacteriol 49, 1457-1469], was further characterized by determination of dna base composition, whole-cell protein sds-page analysis, dna-dna hybridization, 16s rrna gene sequencing and host specificity. these isolates were collected from the wild legumes amphicarpaea trisperma, coronilla varia and gueldenstaedtia multiflora growin ...200111411714
rhizobium mongolense sp. nov. is one of three rhizobial genotypes identified which nodulate and form nitrogen-fixing symbioses with medicago ruthenica [(l.) ledebour].medicago ruthenica [(l.) ledebour] is native to inner mongolia where rhizosphere samples were collected for the isolation of 106 rhizobial cultures. besides nodulating the original trap host, the isolates formed nitrogen-fixing symbioses with phaseolus vulgaris. only half of the isolates nodulated alfalfa (medicago sativa), but these did not form nitrogen-fixing symbioses. rhizobium tropici also formed nitrogen-fixing symbioses with medicago ruthenica. a total of 56 distinctive multilocus electr ...19989542071
[genetic diversity of rhizobia of medicago edgeworthii by aflp and rflp analysis].two hundred and ninety one isolates of rhizobia sampled from root nodules of medicago edgeworthii which came from yun nan province in china were analyzed by amplified restriction fragment polymorphism(aflp) technique. according to the aflp banding patterns, the results showed most of these isolates were genetically diversity. ninety isolates were selected as representing the diversity among the 291 isolates. the 90 isolates were clustered into three groups at the level of similarity of 79% by co ...200012548952
rhizobium oryzae sp. nov., isolated from the wild rice oryza alta.during a study of endophytic nitrogen-fixing bacteria present in the wild rice species oryza alta, eight novel isolates were obtained from surface-sterilized roots and classified in the genus rhizobium on the basis of almost-complete 16s rrna gene sequence analysis. these strains can nodulate phaseolus vulgaris and glycine max. the highly similar protein patterns, dna fingerprint patterns of insertion sequence-based pcr (is-pcr) and dna-dna hybridizations showed that these novel isolates were me ...200818768622
diversity of 16s rdna sequences of rhizobium spp. implications for species determinations.comparative analysis of 70 16s rdna sequences representing 20 rhizobium species (including pathogenic agrobacterium spp.) was conducted using maximum likelihood to establish relationships of species using multiple sequences. there is no significant internal division of the rhizobium clade to suggest that it represents more than one genus. plant pathogenic (agrobacterium) species are distributed within the genus. the analysis supported the synonymy of some species (rhizobium gallicum and rhizobiu ...200415336412
rhizobium azibense sp. nov., a nitrogen fixing bacterium isolated from root-nodules of phaseolus vulgaris.three microbial strains isolated from common beans, 23c2t (tunisia), gr42 (spain) and ie4868 (mexico), which have been identified previously as representing a genomic group closely related to rhizobium gallicum, are further studied here. their 16s rrna genes showed 98.5-99% similarity with rhizobium loessense ccbau 7190bt, r. gallicum r602spt, rhizobium mongolense usda 1844t and rhizobium yanglingense ccbau 71623t. phylogenetic analysis based on reca, atpd, dnak and thrc sequences showed that th ...201424478208
Displaying items 1 - 11 of 11