陆生伊萨酵母降解L-苹果酸和柠檬酸的研究

Degradation of L-Malic and Critic Acids by Issatchenkia terricola

利用陆生伊萨酵母对L-苹果酸和柠檬酸进行降解,考察菌株的耐受性,陆生伊萨酵母可耐受SO2的最大质量浓度为450mg/L、体积分数5%的酒精、最低pH值为2的酸度。对培养基进行优化,最佳氮源胰蛋白胨质量浓度为0.5g/100mL时,降酸率最高,达90%以上。对降酸条件进行优化,接种量在1.25×106～7.5×106CFU/mL范围内,培养时间为60h时,菌株对质量浓度为8～20g/L的L-苹果酸和质量浓度为8～12g/L柠檬酸降解率均达90%以上。

The degradation potential of Issatchenkia terricola fermentation to L-malic acid and citric acid was explored.The maximum concentrations of SO2 and alcohol and the minimum pH level that the strain could tolerate were 450 mg/L,5% and 2,respectively.The medium and fermentation conditions for the degradation of both acids by the strain were optimized based on deacidification rate.When the concentration of the determined optimum nitrogen source tryptone was 0.5 g/100 mL,the deacidification rate reached its maximum level,over 90%.The optimum inoculum size and incubation duration were 1.25×106-7.5×106 CFU/mL and 60 h,respectively,and the resulting degradation rates of 8-20 g/L L-malic acid and 8-12 g/L critic acid reached over 90%.