响应面法优化乳酸菌产抗真菌物质的培养条件

为提高实验室保存的乳酸菌N22产抗真菌物质的产量, 以毕赤酵母为指示菌, 产生的抑菌圈大小为评价指标, 通过响应面法优化乳酸菌产抗真菌物质的培养条件。对MRS培养基碳源、氮源进行优化, 考查不同温度、初始pH值和发酵时间对乳酸菌产抗真菌物质的影响, 温度、初始pH值和发酵时间是主要影响因素, 最后采用Box-Behnken试验设计和响应面法分析确定乳酸菌最佳培养条件为34.16 ℃、初始pH值为5.33、培养35.44 h, 此时, 最大抑菌圈直径为16.34 mm, 可取率为97.90%。经验证, 最大抑菌圈直径为16.58 mm。该培养条件增加了乳酸菌抗真菌物质的产量。

Optimization of Culture Conditions for the Production of Antifungal Substances by Lactic Acid Bacteria Using Response Surface Method

In order to improve the yield of antifungal substances produced by Lactobacillus paracasei （L. paracasei） N22 obtained previously, the response surface method was used to optimize the culture conditions for antifungal substances produced by L. paracasei N22, with Pichia pastoris as the yeast indicator and the size of inhibition zone as the evaluation index. The carbon source and nitrogen source in the MRS culture medium were optimized, and the effects of different levels of culture temperature, initial pH value and fermentation time on yield of antifungal substances produced by L. paracasei N22 were assessed. The results showed that the culture temperature, initial pH value and fermentation time were the main determinative factors. The optimal culture conditions for antifungal substances produced by L. paracasei N22 were determined by using Box-Behnken experiment design and response surface method the culture temperature was 34.16 ℃, the initial pH value was 5.33, and the culture duration was 35.44 h. Under these conditions, the largest diameter of inhibition zone was 16.34 mm, and the desirable rate was 97.90%. After verification, the largest diameter of inhibition zone was 16.58 mm. The culture conditions determined in this study increase the yield of antifungal substances produced by lactic acid bacteria.