초록
<P>Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which <I>Bacillus coagulans</I> strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by <I>B. coagulans</I> is revealed. Betaine could enhance lactic acid production by protecting <SMALL>L</SMALL>-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by <I>B. coagulans</I> is thus developed by using betaine and beet molasses.</P>