Identification and characterization of genes conferring salt tolerance to Escherichia coli from pond water metagenome.
Metagenomics provides culture-independent access to gene pool of the whole microbial communities. To identify genes responsible for salt tolerance in unculturable bacteria, Escherichia coli clones were enriched with an ability to grow at inhibitory NaCl concentrations (750mM) from a pond water metagenomic library. From two unique clones, genes encoding for proteins with similarity to a putative general stress protein (GspM) harbouring GsiB domain and a putative enoyl-CoA hydratase (EchM) were identified to be responsible for salt tolerance. The gspM was expressed by its native promoter whereas the echM was expressed from the lacZ promoter of the plasmid. EchM was overexpressed with a hexahistidyl tag. Purified EchM showed crotonyl-CoA hydratase activity. These genes have potential application in generating salt tolerant recombinant bacteria or transgenic plants.
Microbial Genomics and Biotechnology Group, Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), Mall Road, New Delhi 110007, India.
Raj Kishor
RK
Kapardar
Ravi
R
Ranjan
Amit
A
Grover
Munish
M
Puri
Rakesh
R
Sharma
D000222:Adaptation, Physiological / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D005788:Gene Pool; D005798:Genes, Bacterial; D012965:Sodium Chloride
D012965:Sodium Chloride