枯草菌素产生菌芽孢杆菌FB123的发酵条件优化及其16S rRNA序列分析

Optimization of fermentation conditions for subtilin production by Bacillus sp. FB123 and analysis of its 16S rRNA sequence

对芽孢杆菌FB123产枯草菌素发酵条件进行了优化并对菌株进行了16S rRNA分子鉴定。采用不同培养基配方、单因素及正交设计等试验对FB123培养基、发酵条件进行了优化,FB123的枯草菌素产量(透明圈直径:cm)从1.1cm增加到1.67cm;生物量提高了2.5倍。最佳培养基为(%):葡萄糖0.5,蛋白胨1.0,牛肉膏0.5,酵母膏0.1,pH7.5;培养条件:培养温度28℃,培养时间32h。进一步克隆测定了该菌16SrRNA基因序列,系统进化树分析表明该菌与枯草芽孢杆菌(Bacillus subtilis)具有最紧密亲缘关系。

The fermentation conditions for subtilin production by Bacillus sp. FB123 was optimized and the molecular identification of the strain by its 16S rRNA gene was carried out. The subtilin production and biomass of FB123 were increased via different culture media, series single factor trials and orthogonal comparisons. Subtilin production （the diameter of clarity zone： cm） was increased from 1. lcm to 1.67cm, and biomass had enhanced 2.5 times. The optimal culture medium and conditions for subtilin production by Bacillus subtilis FB123 were obtained. The culture medium contained： glucose 0.5 %, peptone 1.0 %, beef extract 0.5 %, yeast extract 0.1%, pH 7.5 ; culture temperature at 28 ~C, fermentation time for 32 hours. The 16S rRNA gene was cloned and analyzed. The phylogenic tree analysis showed that the 16S rRNA marker of FB123 showed highest homology to that of Bacillus subtilis.