响应面法优化当归补血汤液体发酵工艺

为确定当归补血汤液体发酵的最佳工艺，本试验采用枯草芽孢杆菌为发酵菌种，以多糖提取率为评价指标进行液体发酵工艺优化。首先采用单因素试验考察发酵培养基中葡萄糖和蛋白胨添加量、菌液接种量和发酵时间对多糖提取率的影响，再以此为基础，采用Box-Behnken中心组合试验设计法，选取葡萄糖添加量、蛋白胨添加量、接种量、发酵时间为发酵优化的4个因素，以多糖提取率为响应值，设计4因素3水平的试验方案并进行响应面分析，以确定各因素与响应值多糖提取率的关系。结果显示，各因素对多糖提取率变化的贡献大小依次为葡萄糖添加量、蛋白胨添加量、接种量、发酵时间；利用响应面分析结果显示，蛋白胨添加量与接种量和发酵时间、接种量和发酵时间的交互作用较为显著，最终确定最佳发酵工艺条件为：葡萄糖添加量0.95%，蛋白胨添加量1.52%，接种量2.92%，发酵时间35.8 h。该条件下多糖提取率达到9.23%，与未发酵组（4.62%）相比，多糖含量提高近2倍。该工艺对液体发酵当归补血汤产多糖优化效果显著，为发酵当归补血汤的进一步开发利用提供了理论基础。

Optimization of Liquid Fermentation Process for Danggui Buxue Tang by Response Surface Methodology

In order to determine the optimal process for the liquid fermentation of Danggui Buxue Tang,Bacillus subtilis was used as the fermentation strain and the liquid fermentation was carried out with the polysaccharide extraction rate as the evaluation index in this study.Firstly,the effects of glucose and peptone addition in fermentation medium,inoculum volume,and fermentation time on the extraction rate of polysaccharides were studied by single factor experiment.Based on the single factor experiment,the Box-Behnken Center combined test design was used to optimize the four factors of fermentation optimization,such as glucose addition,peptone addition,inoculum size and fermentation time,based on the response value of polysaccharide extraction.The four-factor and three-level test protocol was designed and response surface analysis was performed to determine the relationship between various factors and the response rate of polysaccharide extraction rate.The results showed that the contribution of four factors to the change of polysaccharide extraction rate was glucose addition,peptone addition,inoculum volume and fermentation time.And the interaction between peptone addition and the inoculum volume,peptone addition and fermentation time,inoculum volume and fermentation time were significant.The best process conditions under the experimental condition 0.95% of glucose addition,1.52% of peptone addition,2.92% of inoculum volume,and 35.8 h of fermentation time.Under this condition,the polysaccharide extraction rate reached 9.23%,which was nearly doubled compared with the unfermented group (4.62%).The process had a significant effect on the optimization of polysaccharides produced by liquid fermentation Danggui Buxue Tang,and could provide a theoretical basis for the further development and utilization of fermented Danggui Buxue Tang.