莫海威芽孢杆菌J7产抑菌物质培养基发酵优化

Fermentation Optimization of Culture Medium for Antibacterial Material Production of Bacillus mojavensis J7

为将莫海威芽孢杆菌J7推广应用,获得更多其产生的抑菌物质,考察培养基及其组分、发酵条件对菌体抑菌性能的影响;通过Plackett-Burman试验、最陡爬坡试验和Box-Behnken试验优化发酵工艺。试验结果表明,Landy培养基为莫海威芽孢杆菌J7产生抑菌物质的最适发酵培养基,蔗糖和酵母浸粉分别为最适碳源和氮源,30℃、36 h培养、培养基初始p H 7.0、接种量6%为最适发酵条件。其中,蔗糖添加量、酵母浸粉添加量和发酵温度是影响莫海威芽孢杆菌J7抑菌物质产生的3个主要因素。根据主要因素的效应大小设计最陡爬坡试验,确定响应面实验的中心点。优化后的蔗糖添加量为16.9 g/L,酵母浸粉添加量为6.6 g/L,发酵温度为29.7℃,其它成分不变。验证试验结果表明,优化后等量培养基内的抑菌物质产量提高了38.89%。验证试验结果为预测值的97.89%,说明该模型对菌株J7的实际发酵生产具有指导意义。

In order to popularization and application of Bacillus mojavensis J7 for obtaining more antibacterial materials, the effects of the medium and its composition and fermentation conditions on the antibacterial properties of strain J7 were investigated. The Plackett-Burman experiments, the steepest climbing experiments and Box-Behnken experiments were used to optimize fermentation technology. Experiment results show that, the Landy medium which could make B.mojavensis J7 to produce the most antibacterial materials was as an optimum fermentation medium. The sugar and yeast powder were the optimum carbon source and nitrogen source, respectively. The best fermentation conditions were 30 ℃,36 h, initial p H 7.0, 6% inoculum size. Sucrose content, yeast powder content and fermentation temperature were three main influencing factors. According to the size of the effect of the main influencing factors the steepest climbing experiment was adopted to determine the center of response surface experiments. Optimized sucrose content was 16.9 g/L, yeast powder content was 16.9 g/L, the fermentation temperature was 29.7 ℃, other ingredients was unchanged. The antibacterial material relative production increased by 38.89% in the same amount of medium than before optimization with the optimized medium and culture conditions. The observed value was 97.89% as compared to the predicted value in validation experiments. This result showed that the model has a guiding significance to the actual fermentation production of strain J7.