Xu Ke, Xu Ping
State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
PLoS One. 2014 Jun 23;9(6):e100731. doi: 10.1371/journal.pone.0100731. eCollection 2014.
Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-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 B. coagulans is thus developed by using betaine and beet molasses.
乳酸是一种具有多种工业应用的重要化学品，可通过发酵高效生产，其中凝结芽孢杆菌菌株表现出优异性能。甜菜碱作为一种有效的渗透保护剂可促进乳酸发酵。在此，揭示了甜菜碱对凝结芽孢杆菌发酵的积极作用。甜菜碱可通过保护L - LDH活性和细胞生长免受渗透抑制来提高乳酸产量，特别是在高葡萄糖浓度和有机氮营养较差的情况下。与不添加甜菜碱的发酵相比，添加0.05 g/L甜菜碱的发酵可多产生17.9%的乳酸。富含蔗糖和甜菜碱的甜菜糖蜜用于补料分批发酵，使生产率提高了22%。因此，通过使用甜菜碱和甜菜糖蜜开发了凝结芽孢杆菌的高效乳酸发酵。
