中文摘要：

以2株优良的L-乳酸生产菌株凝结芽孢杆菌XZL4和凝结芽孢杆菌NL01为研究对象,从降低培养基原料成本的角度出发,考察了5种有机氮源、2种无机氮源以及4种无机盐对凝结芽孢杆菌发酵过程的影响。实验结果表明,酵母粉是最优氮源,但不同菌株对酵母粉的依赖程度不一;磷酸二氢钾可以有效促进L-乳酸的生产,适量磷酸二氢钾的添加甚至可以取代部分酵母粉的作用,极大地降低了培养基成本。

英文摘要：

Bacillus coagulans is a wonderful L-lactic acid producer. In this study, two B. coagulans strains, B. coagulans NL01 and XZL4, were taken as examples to investigate the effects of nitrogen source and inorganic salt on L-lactic acid production. In order to re-duce the cost of culture media, 5 kinds of organic nitrogen, 2 kinds of inorganic nitrogen, and 4 kinds of inorganic salt were selected to investigate their effects on fermentation. The results showed that yeast exact was the best nitrogen source, but its effects on B. coagu-lans NL01 and XZL4 were different. Compared with previous reports, the most exciting result was that potassium dihydrogen phosphate could intensively improve the concentration of L-lactic acid even instead of partial yeast extract. And this would distinctly reduce the cost of culture media.