芽孢杆菌配伍发酵菜籽粕产中性蛋白酶条件研究

Fermentation conditions of neutral protease on rapeseed meal from Bacillus compatibility

为了提高中性蛋白酶的产量,采用响应曲面法研究了微生物配伍发酵菜籽粕产中性蛋白酶的条件。确定了微生物配伍菌种为Bacillus subtilis UV-7+UN-11(1∶1);在单因素实验基础上,以中性蛋白酶活力为指标,进行BoxBehnken设计,获得最佳发酵条件为:发酵温度35.7℃,转速193r/min,接种量为7.58%,该条件下中性蛋白酶活力的理论值为2709.9U/m L,在最佳条件下进行3次验证,中性蛋白酶活力为(2714.5±2.4)U/m L,与理论预测值基本一致,比未优化前的2602.7U/m L提高了4.3%。

In order to increase the yield of neutral protease,the fermentation conditions of strain compatibility based on rapeseed meal were optimized by single factor tests and Response Surface Methodology（ RSM）.The results showed that the best strain compatibility was Bacillus subtilis UV- 7 and UN- 11 （ 1 ： 1 ）. The second - order polynomial model for neutral protease was established, and the optimal fermentation technology was obtained as following：temperature 35.7℃, rotational speed 193r/min, and inoculum concentration 7.58% .Under the optimal conditions,the predicted yield of fitted model was 2709.9U/mL and verification test result was 2714.5± 2.4U/mL, which increased 4.3% compared with the original conditions.