藏灵菇菌增殖条件及其乳酸发酵特性的研究

Research on Proliferation Conditions and Lactic Acid Fermentation Characteristics of Tibetan Kefir Grains

对藏灵菇菌增殖条件及其产乳酸特性进行了研究。藏灵菇增殖适宜条件为:乳浓度60%,培养温度28℃,接种量5%,pH值6.6,250 mL三角瓶装液量50 mL,转数100 r.m in-1。连续培养5代后,其增殖率达到108%。藏灵菇产酸能力较强,培养20 h,pH值迅速下降到4.62,酸度增至109°T。外加碳源不利于藏灵菇生长,而添加蛋白胨和酵母浸提物则对藏灵菇增殖有促进作用。

This paper presents proliferation conditions and lactic acid fermentation characteristics of Tibetan kefir grains.Proper proliferation conditions for Tibetan kefir grains include： culture temperature at 28 ℃,milk concentration at 60 %,pH value at 6.6,inoculum concentration at 5 %,50 mL milk in a 250 mL Erlenmeyer flask,and a rotation speed of 100 r·min^-1.The rate of proliferation reaches 108 % after cultivation of five consecutive generations.Tibetan kefir grains feature a high capacity of producing lactic acid, as the acidity reaches 109°T （pH= 4.62） after a cultivation duration of 20 h. Adding carbon sources hinders proliferation of Tibetan kefir grains, while adding peptone and yeast extract facilitates their proliferation.