IS981-mediated adaptive evolution recovers lactate production by ldhB transcription activation in a lactate dehydrogenase-deficient strain of Lactococcus lactis.

ABSTRACT: Lactococcus lactis NZ9010 in which the las operon-encoded ldh gene was replaced with an erythromycin resistance gene cassette displayed a stable phenotype when grown under aerobic conditions, and its main end products of fermentation under these conditions were acetate and acetoin. However, under anaerobic conditions, the growth of these cells was strongly retarded while the main end products of fermentation were acetate and ethanol. Upon prolonged subculturing of this strain under anaerobic conditions, both the growth rate and the ability to produce lactate were recovered after a variable number of generations. This recovery was shown to be due to the transcriptional activation of a silent ldhB gene coding for an Ldh protein (LdhB) with kinetic parameters different from those of the nativ

SUBMITTER: Bongers RS 

PROVIDER: S-EPMC165757 | biostudies-literature | 2003 Aug

REPOSITORIES: biostudies-literature