甘南牧区牦牛乳酸奶中产乳糖酶菌株的筛选、鉴定及产酶条件研究  

Study on screening,identification and fermentation conditions of lactase producing microorganisms from yark yoghourt from gannan pasuring area

作　　者：巨蕾[1] 梁琪[1] 乔海军[1] 米兰[1] 张炎[1] 杨敏[1] 宋雪梅[1] 张卫兵[1] 甘伯中[1] 

机构地区：[1]甘肃农业大学食品科学与工程学院,甘肃省功能乳品工程实验室,甘肃兰州730070

出　　处：《食品工业科技》2012年第12期239-242,254,共5页Science and Technology of Food Industry

基　　金：甘肃省科技重大专项(1002FKDA046);甘肃省农业生物技术专项(GNSW-2010-17);兰州市政研产合作支撑计划项目(2011-1-105)

摘　　要：采用含X-gal的筛选培养基,从甘南牧区采集的25份牦牛乳酸奶中分离筛选到20株产乳糖酶微生物,其中菌株SYA2产乳糖酶活力最高,综合形态学、生理生化特征和16S rDNA序列同源分析结果,将其鉴定为肠杆菌属(Enterobacter sp.)。对菌株Enterobacter sp.SYA2产酶条件的研究表明:发酵温度为37℃,发酵周期为24h,培养基初始pH6.5时有利于该菌株产酶,此条件下乳糖酶活力为8.00U/mL。20 strains with lactase activity were isolated from 25 Yak Yoghourt samples collected from Gannan pasuring area of Gansu Province,using screening medium include X-gal.An efficient lactase producing strain SYA2 screened out from 20 strains was identified as Enterobacter sp by the means of morphological feature observation,physiological and biochemical characteristics measurement and 16S rDNA sequence analysis.The result showed that the optimal culture conditions were as follows：culture temperature 37℃,culture time 24h,initiation pH 6.5 of the culture medium.Under this condition,the lactase activity reached 8.00U/mL.

关 键 词：牦牛乳酸奶 乳糖酶 筛选 产酶条件 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]