Studies on Extracellular Polysaccharide from Rhizobium meliloti.
نویسندگان
چکیده
منابع مشابه
Partial characterization and photolabeling of a Rhizobium meliloti polysaccharide methyltransferase with S-adenosylmethionine.
S-Adenosylmethionine (SAM) has been used to directly cross-link a polysaccharide specific methyltransferase isolated from Rhizobium meliloti HA. This peculiar enzyme transfers a methyl group to the 2-O-galacturonosyl residue of a teichuronic type polysaccharide and was very unstable. The apparent Km for SAM was 0.46 mM. The Hill coefficient, n, was 1. The enzyme had an optimum pH of 8.2 and req...
متن کاملInterference between Rhizobium meliloti and Rhizobium trifolii nodulation genes: genetic basis of R. meliloti dominance.
Transfer of an IncP plasmid carrying the Rhizobium meliloti nodFE, nodG, and nodH genes to Rhizobium trifolii enabled R. trifolii to nodulate alfalfa (Medicago sativa), the normal host of R. meliloti. Using transposon Tn5-linked mutations and in vitro-constructed deletions of the R. meliloti nodFE, nodG, and nodH genes, we showed that R. meliloti nodH was required for R. trifolii to elicit both...
متن کاملExtracellular polysaccharide production by a Rhizobium sp. isolated from legume herb Crotalaria saltiana Andr
A symbiont, isolated from root nodules of Crotalaria saltiana Andr., was identified as Rhizobium sp. It produced large amount of extracellular polysaccharides (EPS) in broth culture in yeast extract mannitol (YEM) medium. The EPS production and growth started simultaneously, though they have different stationary phases. The symbiont produced maximum EPS (16 μg/mL) when the medium was supplement...
متن کاملHigh-frequency transformation of Rhizobium meliloti.
Transformation of R factor RP4 and its derivative pRK290 from Escherichia coli to Rhizobium meliloti is reported. The efficiency of transformation was in the range of 10(-5) per viable cell. In addition, chromosomal DNA prepared from one R. meliloti strain resistant to streptomycin was transferred to the isoleucine-valine-requiring mutant susceptible to streptomycin.
متن کاملRhizobium meliloti Nodulation Genes: Identification of nodDABC
A set of conserved, or common, bacterial nodulation (nod) loci is required for host plant infection by Rhizobium melioti and other Rhizobium species. Four such genes, nodDABC, have beeii indicated in R. meliloti 021'by genetic analysis and DNA sequencing. An essential step toward Iunderstanding the function of these genes is to characterize their protein products. We used in vitro and maxicell ...
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ژورنال
عنوان ژورنال: Acta Chemica Scandinavica
سال: 1971
ISSN: 0904-213X
DOI: 10.3891/acta.chem.scand.25-1281