凝结芽孢杆菌产β-半乳糖苷酶条件的优化  

Optimization of β-galactosidase production by Bacillus coagulans

作　　者：宋春雷[1] 闫巧娟[2] 江正强[1] 李一男[1] 唐荦[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]中国农业大学工学院,北京100083

出　　处：《中国农业大学学报》2010年第5期110-114,共5页Journal of China Agricultural University

基　　金：教育部新世纪优秀人才支持计划(NCET-08-0534)

摘　　要：从土壤中筛选得到1株高产β-半乳糖苷酶的凝结芽孢杆菌,研究该菌产β-半乳糖苷酶的发酵条件。结果表明:产酶适宜的培养基配方为蔗糖10 g/L,麦芽糖5 g/L,可溶性淀粉5 g/L,酵母提取物6.7 g/L,胰蛋白胨13.3 g/L,KCl 1.5 g/L;产酶的最适发酵温度为45℃。培养48 h总酶活力达到7.1 U/mL,60 h胞外酶活力最高为3.0 U/mL。胞外酶的最适pH为6.0,最适温度65℃。该酶能够完全水解乳糖,可适用于无乳糖乳制品的生产。A strain of Bacillus coagulans L42,which enables a high rate production of β-galactosidase,was isolated from soil sample.The fermentation conditions were optimized for this enzyme.The results showed that Bacillus coagulans L42 grow best at 45 ℃ with the medium（g/L） of sucrose 10,maltose 5,soluble starch 5,yeast extract 6.7,tryptone 13.3 and KCl 1.5.After fermentation of 48 h,the total enzyme activity was up to 7.1 U/mL,while the highest activity of the secreted extracellular enzyme was 3.0 U/mL after fermentation of 60 h.The optimum temperature and pH of the extracellular enzyme activity were 65 ℃ and pH 6.0,respectively.The enzyme could completely hydrolyze lactose into glucose and galactose.The enzyme can be applied to the production of lactose-free dairy products.

关 键 词：凝结芽孢杆菌 Β-半乳糖苷酶 胞外酶 发酵 

分 类 号：TS201.3[轻工技术与工程—食品科学]