Effect of overexpressing nhaA and nhaR on sodium tolerance and lactate production in Escherichia coli.

ABSTRACT:

Background

Like other bacteria, Escherichia coli must carefully regulate the intracellular concentration of sodium ion (Na+). During the bacterial production of any organic acid, cations like Na+ invariably accumulate during a process which must maintain a near neutral pH. In this study, the E. coli nhaA gene encoding the Na+/H+ antiporter membrane protein and the nhaR gene encoding the NhaA regulatory protein were overexpressed in wild-type E. coli MG1655 and in MG1655 pflB (ALS1317) which lacks pyruvate formate lyase activity and thus accumulates lactate under anaerobic conditions.

Results

Expression of either the nhaA or nhaR gene on the high copy inducible expression vector pTrc99A caused a significant reduction in the growth rate of MG1655. No change in growth rate was

SUBMITTER: Wu X 

PROVIDER: S-EPMC3599867 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature