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.
出处
《食品工业科技》
CAS
CSCD
北大核心
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)
关键词
牦牛乳酸奶
乳糖酶
筛选
产酶条件
yak yoghourt； lactase； screening； lactase production conditions
