杆菌肽产生菌的诱变育种及培养基优化

Mutagenesis Breeding and Optimization for High Production of Bacitracin by Bacillus licheniformis

以地衣芽孢杆菌Bacillus licheniformis SIPI-669-3为出发菌株进行诱变选育和发酵培养基优化,以提高杆菌肽产量。采用硫酸二甲酯(DMS)、紫外(UV)及钴-60(60Co)射线对SIPI-669-3进行诱变选育,并采用单因素试验和响应面法优化高产菌株发酵培养基。经过连续复合诱变,筛得高产突变株SIPI-93-14,产量较出发菌株提高了81.4%。优化后的发酵培养基碳、氮源为淀粉5.71%、豆粕10.0%和硫酸铵0.15%,此条件下杆菌肽产量较优化前提高14.5%。

The mutagenesis breeding and culture medium optimization were applied to obtain a higher bacitracin-producing strain. Bacillus licheniformis SIPI-669-3 was selected as the original strain. It was mutagened by dimethyl sulfate （DMS）, UV radiation and ^60Co. A mutate SIPI-3,93-14 was found and its fermentation yield was 81.4 % higher than the original strain. Single factor experiment and response surface methodology were utlized for the optimization of fermentation culture medium. The optimal fermentation culture medium was as follows： starch 5.71%, soybean meal 10.0 %, ammonium sulfate 0.15 %. Under such conditions, the yield of bacitracin was 14.5 % higher than the former.