响应面法优化蜡质芽孢杆菌低产正丙醇发酵工艺

为优化从浓香型白酒酿酒大曲和糟醅中分离出的低产正丙醇蜡质芽孢杆菌(Bacillus cereus)发酵工艺,本文通过单因素试验考察该菌发酵时间、接种量、发酵温度以及发酵液初始pH四个主要因素对发酵液中正丙醇含量的影响。然后以正丙醇含量为响应值,进行响应面分析和优化,建立了B. cereus发酵工艺的回归模型。结果表明,最佳发酵工艺为发酵时间33 h,接种量4.9%,发酵温度32 ℃,发酵液初始pH7.0。在此条件下,发酵液中正丙醇含量为(0.70±0.0012) mg/100 mL,和模型的预测值相吻合。

Optimization of Low Yield Positive N-propyl Alcohol Fermentation Process of Bacillus cereus by Response Surface Methodology

In order to optimize the separation of Luzhou flavor liquor Daqu and fermented grains in the low yield of n-propyl alcohol fermentation process of Bacillus cereus, single factor experiments were conducted to investigate the effects of four main factors, including fermentation time, inoculation amount of Bacillus cereus, fermentation temperature and initial pH of fermentation broth, on the content of n-propyl alcohol in fermentation broth. Then the response surface analysis and optimization were carried out with the response value of normal as the response value to establish a regression model for the fermentation process of Bacillus cereus. The results showed that the optimum fermentation time was 33 h, the inoculation amount of Bacillus cereus was 4.9%, the fermentation temperature was 32℃, and the initial pH of fermentation broth was pH7.0. Under the condition, the content of n-propyl alcohol in the fermentation broth was (0.70±0.0012) mg/100 mL, which had accordance with the predicted value of the model.