菜籽粕硫甙生物降解工艺优化及其动力学研究

Optimization of biodegradation process and kinetics of glucosinolate from rapeseed meal

中文关键词:  硫甙  菜籽粕  固体发酵  菌株复配  降解动力学

英文关键词:glucosinolate  rapeseed meal  solid fermentation  strain recombination  degradation kinetics

中文摘要:

      目的 优化菜籽粕硫甙降解工艺, 并研究生物发酵过程中优势菌株对硫甙的降解动力学。方法 以菜籽粕为原料, 以实验室自筛菌种B38(鉴定为短小芽孢杆菌Bacillus pumilus)与商业菌株(植物乳杆菌LP21825、枯草芽孢杆菌BS20445)进行复配, 确定最佳硫甙降解菌株组合, 进一步优化硫甙降解工艺, 并对降解率进行拟合, 选用Logistic方程来适配发酵过程中硫甙浓度的变化。结果 结果表明B38+BS20445为最佳菌株组合, 确定最佳硫甙降解工艺为料液比1:1.5 (g:mL), 发酵时间48 h, 接种量10%, 此时硫甙降解率为56.66%, 并且菜籽粕经发酵后蛋白含量与酸度均有所增加。硫甙生物降解过程符合Logistic动力学方程, 其R2大于0.99, 表明拟合性良好, 进一步说明模型能够很好地描述和预测菜籽粕硫甙的降解过程。结论 菌种复配发酵能提高菜籽粕硫甙降解率, 降低菜籽粕毒性, 为菜籽粕的应用提供重要理论基础。

英文摘要:

      Objective To optimize the degradation process of glucosinolates in rapeseed meal and study the degradation kinetics of glucosinolates by dominant strains during biological fermentation. Methods Using rapeseed meal as raw material, a laboratory self screened strain B38 (identified as Bacillus pumilus) was mixed with commercial strains (Lactobacillus plantarum LP21825, Bacillus subtilis BS20445) to determine the optimal combination of glucosinolates degrading strains. The glucosinolates degradation process was further optimized, and the degradation rate was fitted. Logistic equations were used to adapt to changes in glucosinolates concentration during the fermentation process. Results The result showed that B38+BS20445 was the optimal strain combination, and the optimal glucosinolates degradation process was determined as follows: Material liquid ratio 1:1.5 (g:mL), fermentation time 48 hours, inoculation amount 10%. At this time, the glucosinolates degradation rate was 56.66%, and the protein content and acidity of rapeseed meal increased after fermentation. The biodegradation process of glucosinolates conformed to the logistic kinetic equation, with an R2 greater than 0.99, indicating good fitting. This further indicated that the model could effectively describe and predict the degradation process of glucosinolates in rapeseed meal. Conclusion The mixed fermentation of strains can improve the degradation rate of glucosinolates in rapeseed meal, reduce the toxicity of rapeseed meal, and provide an important theoretical basis for the application of rapeseed meal.