可降解咖啡碱的酵母菌菌种筛选及其培养条件的优化

Selection of Caffeine Degrading Yeast and Optimization of Culture Conditions

从贵州省毕节市金沙县茶叶种植基地的土壤中分离得到一株可降解咖啡碱的真菌,经表型特征、内转录间隔区序列测定及系统发育树分析鉴定为酿酒酵母菌(Saccharomyces cerevisiae)同源菌,命名为Y-1。通过单因素试验及响应面试验设计,以咖啡碱降解率为指标,得到响应面回归模型预测方程,根据预测方程,确定菌株Y-1最优的培养条件为:温度31.00℃,发酵时间46.60 h,咖啡碱添加量0.50 mg/mL、菌种添加量6.90%。在此条件下,利用菌株Y-1在培养基中降解咖啡碱,咖啡碱降解率最高可达(59.39±0.28)。

A caffeine-degrading fungus was isolated from the soil in Jinsha County,Bijie City,Guizhou Province. An analysis of its phenotypic characteristics, internal transcriptional spacer sequences, and phylogenetic tree revealed that the fungus was a homologous strain of Saccharomyces cerevisiae(strain Y-1).Single-factor and response surface tests yielded a prediction equation for a response surface regression model that useing caffeine degradation rate as an index. According to the prediction equation,the optimal culture conditions for strain Y-1 were as follows:temperature 31.00 ℃,fermentation time 46.60 h,caffeine addition0.50 mg/mL,strain addition 6.90%. Under these conditions,the caffeine degradation rate was(59.39±0.28)%.