Abstract:

Several strains (species) of lactic acid bacteria (LAB) such as Lactococcus lactis can undergo respiration metabolism and thrive in the presence of both oxygen and a heme source. Genetic evidence suggests that cydA genes encoding cytochrome d oxidase are expressed at the end of log phase, and aerobic respiration is regulated by the catabolite control protein A (CcpA) acting as“ a switch” in LAB strains, therefore the strains present some oxygen and acid resistance. Compared to fermentation, aerobic respiration can prompt effectively the achievement of high biomass, the maintenance of high pH value of culture medium and the increases of adverse resistance and survival ability. It means that the controlled changes in cultivation conditions may increase the proliferation potential and survival ability of LAB, which can widen their application scope in food fermentation industry.

Key words: lactic acid bacteria, aerobic proliferation, respiration metabolism, genetic characteristics