通过20keV氮离子注入L-乳酸生产菌(Bacillus coagulans)筛选到一株产量比出发菌株提高10%的高产菌株RS12-6C,经多次传代实验表明该菌遗传稳定性较好.并对其发酵条件如接种量、装液量、摇床转速、温度等进行初步优化,在含糖150g/L的摇瓶中发酵,其L-乳酸产量达到117g/L.

Through 20 keV N~+ implanting into L-lactic acid producing bacteria Bacillus coagulans, a high-yield mutant strain RS12-6C was obtained. Its lactic acid yield was increased by 10% than that of original. The culturing conditions such as pH control, oxygen supply and temperature was also studied deliberately. And the optimal carbon and nitrogen source and their optimal sugar concentration etc,were determined. The concentration of L-lactic acid reached to 117 g/L under the condition of 150 g/L glucose in fermentation medium.