菜籽粕混合菌固体发酵脱毒条件的响应面优化研究

Detoxification Conditions of Solid-State Fermentation from Rapeseed Meal by Mixture Strains Using Response Surface Methodology

为找到一种脱毒较为彻底且稳定的菜籽粕脱毒方法,以复合芽孢杆菌为发酵剂,采用单因素试验研究了葡萄糖和硫酸铵添加量、料水比、接种量、起始pH、发酵温度及发酵时间等发酵条件对硫代葡萄糖苷降解率的影响。在此试验结果的基础上,采用响应面法评价了料水比、接种量、发酵温度和发酵时间及其交互作用对硫代葡萄糖苷降解率的影响,用Design Expert7.1.6软件分析试验数据建立了菜籽粕混合菌固体发酵条件的一个二次多项式数学模型。结果表明:该模型极显著(P<0.001),拟合度良好。得出混菌固体发酵脱毒过程的工艺参数为:接种量7.7%,发酵温度44℃,料水比1.000∶0.585,发酵时间53h。在此条件下,硫代葡萄糖苷降解率达到了94.850 6%。本试验确定了混合菌发酵菜籽粕脱毒的最佳条件,为混合菌发酵菜籽粕降低硫代葡萄糖苷含量的研究提供了相应的工艺参数和理论依据。

In order to obtain an effective and stable method of the detoxification of rapeseed meal, the effects of fermentation conditions such as glucose addition, ammonium sulfate addition, the ratio of substrate to water, inoculation amount, initial pH value, fermentation temperature and fermentation time on the degradation rate of glucosinolate were studied by using a singlefactor test. Then, the effects of ratio of substrate to water, inocu lation amount, fermentation temperature and fermentation time and their interactions on the degradation rate of glucosinolate were evaluated by using a response surface methodology. Data were analyzed with DesignExpert 7.1.6 software. The results showed that a good quadratic polynomial model of conditions of solidstate fer mentation from rapeseed meal was obtained, the model was significant （ P 〈 0. 001 ）, and there was no lack of fit. The high degradation rate of glucosinolate was observed in fermentation processes under the optimal condi tions： the inoculation amount was 7.7 %, fermentation temperature was 44 ℃, ratio of substrate to water was 1. 000：0. 585, and fermentation time was 53 h. Under these conditions, the degradation rate of glucosinolate reached 94. 850 6 %. In conclusion, the optimal fermentation conditions of the detoxification conditions are de termined. The results can be used as technical parameters and theoretic basis for decreasing the degradation rate of glucosinolate with mixture strains on rapeseed meal.