一株乳酸菌的鉴定及其在酸豆乳加工中的应用

Identification of a lactic acid bacterium and its application in fermented soybean drink

对从酸菜汁中分离到的一株乳酸菌菌株L4进行鉴定,通过传统的形态学及生理生化特性分析,初步确定菌株L4为乳酸杆菌属(Lactobacillus)。通过序列比对及构建系统发育树,表明L4与植物乳杆菌(Lactobacillus plantarum)相似性在90%以上,鉴定菌株L4为植物乳杆菌。对菌株L4在豆乳中发酵的酸化能力、后酸化能力及耐受酸能力进行了研究。结果表明,该菌株在豆乳中37℃发酵,15h酸度值为58°T左右;用此菌株发酵的豆乳在4℃贮藏期间也很稳定,20d内酸度变化范围极小,约为4°T;耐受酸能力较强,在pH值为3.0条件下处理120min,菌数存活率为91.2%。

A lactic acid bacteria IA was isolated from pickled cabbage juice. L4 was identified as Lactobacillus plantarum by molecular biological method and the traditional method. The acidification capacity, post acidification capacity and resistance to acid of IA strain were studied. The result showed that the acidity value in soymilk could reach 58°T after 15h fermentation under 37℃. The fermented soybean drink was stable under 4℃ with little change in the acidity. This strain also showed good resistance to acid. After treating under pH value 3.0 for 2h, the bacteria survival rate was 91.2%.