热泉菌Bacillus sp.BI-3产高温脂肪酶的发酵条件优化

Optimization of fermentation conditions of hot spring bacteria Bacillus sp. BI-3 producing thermostable lipase

通过平板透明圈从印度尼西亚热泉样品中筛选出一株高产脂肪酶的菌株Bacillus.sp BI-3。首先以培养温度、p H、碳源、氮源、金属离子、氯化钠添加量及接种量作为唯一变量进行单因素实验,筛选出对酶活有显著影响的单因素取值范围,再利用Box-Behnken设计及响应面分析法进行回归分析以确定最佳发酵条件。结果表明,优化后的发酵培养条件为培养温度49.1℃、蛋白胨0.78%、氯化锶13 mmol/L、接种量1.5%、初始p H 7.0、酵母粉0.4%,优化后发酵上清液的酶活达到224.63 U/m L。

A lipase -producing strain from Indonesia hot spring, named Bacillus sp. BI -3, was screened by transparent circle. The ranges of single factors （culture temperature, pH, carbon sources, nitrogen sources, metal ions, dosage of NaCl and inoculation amount） were selected by single factor experiment firstly. Then, Box - Behnken design and response surface methodology were adopted to determine the optimal fermentation conditions. The results showed that the optimal fermentation conditions of Bacillus sp. BI -3 were obtained as follows： culture temperature 49. 1 ℃, peptone 0.78%, SiCl2 13 mmol/L, inoculation amount 1.5%, initial pH 7.0, yeast powder 0.4%. The enzyme activity of fermented supernatant was 224.63 U/mL after optimization.