用于低乳糖牛奶生产的乳糖酶添加剂候选菌株筛选及粗酶性质研究  

Screening of A Psychrotolerant Bacterium of Planococcus sp. Y Producing Low Temperature Lactose and Preliminary Study on Its Enzyme Activity

作　　者：李荷[1] 张博[1] 张敏文[1] 顾取良[1] 

机构地区：[1]广东药学院生物化学与分子生物学系,广东广州510006

出　　处：《河南农业科学》2011年第4期138-141,145,共5页Journal of Henan Agricultural Sciences

基　　金：国家自然科学基金项目(30570055);广东省科技计划项目(2009B020313005);广东省自然科学基金博士启动基金(9451022401003873);广东药学院博士启动项目(2006JCX06)

摘　　要：在低乳糖牛奶加工过程中需要高活性的低温乳糖酶作为添加剂。为此,从采集土样中分离纯化获得1株低乳糖奶加工过程中需要的高乳糖酶活性候选菌株,应用形态学和分子生物学方法,初步鉴定该菌株为动球菌属(Planococcus sp.),命名为Planococcus sp.Y。研究表明,该菌株是1株低温菌株,其最适生长温度为25℃,最佳生长pH值为7.0,所产酶为胞内酶,粗酶液的最适酸碱度和温度分别为pH7.0和25℃。High activity of cold-adapted low lactase as an additive is necessary in processing low lactose milk.The psychrotrophic and bacterium strain was isolated from surficial soils.A strain capable of producing psychrotrophic a lactase was identified as a Planococcus sp.Y according to the morphological and molecular characteristics.The optimal conditions for the growth of the strain were examined.The optimal temperature and pH value for growth were 25℃ and 7.0,respectively.Study on the activity of the lactase showed that the optimal temperature and pH for the activity of the crude enzyme was 25℃ and 7.0,respectively.The lactase from Planococcus sp.Y was located intracellularly.This will provide a foundation for producing low lactose milk in future.

关 键 词：乳糖酶 筛选 低温菌 

分 类 号：S879.1[农业科学—畜牧兽医]