Dataset Information

Characterization of a Sinorhizobium isolate and its extracellular polymer implicated in pollutant transport in soil.

ABSTRACT: A bacterium isolated from soil (designated 9702-M4) synthesizes an extracellular polymer that facilitates the transport of such hydrophobic pollutants as polynuclear aromatic hydrocarbons, as well as the toxic metals lead and cadmium in soil. Biolog analysis, growth rate determinations, and percent G+C content identify 9702-M4 as a strain of Sinorhizobium meliloti. Sequence analysis of a 16S rDNA fragment gives 9702-M4 a phylogenetic designation most closely related to Sinorhizobium fredii. The extracellular polymer of isolate 9702-M4 is composed of both an extracellular polysaccharide (EPS) and a rough lipopolysaccharide. The EPS component is composed mainly of 4-glucose linkages with monomers of galactose, mannose, and glucuronic acid and has pyruval and acetyl constituents. The lipid fraction and the negative charge associated with carbonyl groups of the exopolymer are thought to account for the binding of polynuclear aromatic hydrocarbons and cationic metals.

SUBMITTER: Janecka J

PROVIDER: S-EPMC126573 | biostudies-literature | 2002 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Characterization of a Sinorhizobium isolate and its extracellular polymer implicated in pollutant transport in soil.

Janecka J J Jenkins M B MB Brackett N S NS Lion L W LW Ghiorse W C WC

Applied and environmental microbiology 20020101 1

A bacterium isolated from soil (designated 9702-M4) synthesizes an extracellular polymer that facilitates the transport of such hydrophobic pollutants as polynuclear aromatic hydrocarbons, as well as the toxic metals lead and cadmium in soil. Biolog analysis, growth rate determinations, and percent G+C content identify 9702-M4 as a strain of Sinorhizobium meliloti. Sequence analysis of a 16S rDNA fragment gives 9702-M4 a phylogenetic designation most closely related to Sinorhizobium fredii. The ...[more]

PMID: 11772656

Similar Datasets

Project description:An exhaustive screening program was applied for scoring a promising L-asparaginase producing-isolate. The recovered isolate was identified biochemically and molecularly and its L-asparaginase productivity was optimized experimentally and by Response Surface Methodology. The produced enzyme was characterized experimentally for its catalytic properties and by bioinformatics analysis for its immunogenicity. The promising L-asparaginase producing-isolate was selected from 722 recovered isolates and identified as Stenotrophomonas maltophilia and deposited at Microbiological Resources Centre (Cairo Mircen) under the code EMCC2297. This isolate produces both intracellular (type I) and extracellular (type II) L-asparaginases with about 4.7 fold higher extracellular L-asparaginase productivity. Bioinformatics analysis revealed clustering of Stenotrophomonas maltophiliaL-asparaginase with those of Pseudomonas species and considerable closeness to the two commercially available L-asparaginases of E. coli and Erwinia chrysanthemi. Fourteen antigenic regions are predicted for Stenotrophomonas maltophiliaL-asparaginase versus 16 and 18 antigenic regions for the Erwinia chrysanthemi and E. coliL-asparaginases. Type II L-asparaginase productivity of the test isolate reached 4.7 IU/ml/h and exhibited maximum activity with no metal ion requirement at 37 °C, pH 8.6, 40 mM asparagine concentration and could tolerate NaCl concentration up to 500 mM and retain residual activity of 55% at 70 °C after half an hour treatment period. Application both of random mutation by gamma irradiation and Response Surface Methodology that determined 38.11 °C, 6.89 pH, 19.85 h and 179.15 rpm as optimum process parameters could improve the isolate L-asparaginase productivity. Maximum production of about 8 IU/ml/h was obtained with 0.4% dextrose, 0.1% yeast extract and 10 mM magnesium sulphate. In conclusion L-asparaginase of the recovered Stenotrophomonas maltophilia EMCC2297 isolate has characters enabling it to be used for medical therapeutic application.

Dataset Information

Characterization of a Sinorhizobium isolate and its extracellular polymer implicated in pollutant transport in soil.

Publications

Characterization of a Sinorhizobium isolate and its extracellular polymer implicated in pollutant transport in soil.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets