一株马克斯克鲁维酵母菌的生长及酒精发酵特性分析

该文对一株耐高温的马克斯克鲁维酵母菌株HY32的生长及酒精发酵特性进行了研究.与耐高温酿酒活性干酵母TRADY相比,菌株HY32表现出了极好的耐热能力和较好的耐酒精能力.在37℃、42℃、45℃摇瓶培养10h后,菌株HY32的活菌数分别为2.45× 108个/mL、1.76× 108个/mL和0.92× 108个/mL.将菌株TRADY和HY32按相同的接种量转接到添加了4％vol乙醇的液体培养基中,37℃摇瓶培养6h后,菌株HY32的OD600值是菌株TRADY的1.6倍.随着温度的升高和培养基中乙醇浓度的增加,菌株HY32较TRADY的相对耐酒精能力更好.菌株HY32在高温下仍具有一定的产酒能力.采用葡萄糖酒精发酵培养基进行酒精发酵,菌株HY32在42℃和45℃时发酵72h,酒精产率分别为5.25％vol和4.02％vol.木薯酒精发酵实验结果分析表明,菌株HY32的乙酸乙酯产量是酿酒酵母TRADY的10倍左右,而正丙醇和乳酸乙酯等含量较低.

Growth and ethanol fermentation characteristics of a strain of Kluyveromyces marxianus

In this study,the thermotolerant ethanol-producing yeast Kluyveromyces marxianus HY32 was researched in growth and ethanol fermentation abilities.Contrasting Angel temperature resistant alcohol instant active dry yeast TRADY,strain HY32 showed excellent thermotolerant ability.The total count of the strain respectively was 2.45×108cfu/ml,1.76×108cfu/ml and 0.92×108cfu/ml with liquid culture in shake flask for 10h at 37℃,42℃ and 45℃.Strain TRADY could not grow at 45℃.Meanwhile,strain HY32 showed better tolerance to alcohol than strain TRADY.Strain TRADY and HY32 were transfered to liquid culture including 4 ％vol alcohol with the same initial total count,the OD600 value of stain HY32 was 1.6-fold of than of strain TRADY with the culture in shake flask for 6h at 37℃.Strain HY32 showed much better tolerance to alcohol than TRADY with the culture including higher concentration alcohol at a higher temperature.Subsequently,strain HY32 also had certain ability to product ethanol under high temperature.Using glucose ethanol fermentation medium,the ethanol concentration of strain HY32 reached 5.25 ％vol when fermentation was carried out at 42℃ for 72h,and 4.02 ％vol when fermentation was carried out at 45℃ for 72h.The results of cassava ethyl alcohol fermentation showed that the yield of ethyl acetate of strain HY32 was about 10-fold than strain TRADY,and the yield of n-propanol and ethyl lactate of strain HY32 was lower.