| 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。 |
| 关键词: 凝结芽孢杆菌 β-半乳糖苷酶 胞外酶 发酵 |
| DOI：10.11841/j.issn.1007-4333.2010.05.018 |
| 投稿时间：2010-03-10 |
| 基金项目:教育部新世纪优秀人才支持计划(NCET-08-0534)第一作者:宋春雷,硕士研究生,E-mail:sclissr@163.com通讯作者:江正强,教授,主要从事食品酶工程研究,E-mail:zhqjiang@cau.edu.cn |
|
| Optimization of β-galactosidase production by Bacillus coagulans |
|
SONG Chun-lei1, YAN Qiao-juan2, JIANG Zheng-qiang1, LI Yi-nan1, TANG Luo1
|
| (1.College of Food Science and Nutrition Engineering,China Agriculture University,Beijing 100083,China;2.College of Engineering,China Agriculture University,Beijing 100083,China) |
| Abstract: |
| 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. |
| Key words: Bacillus coagulans β-galactosidase extracellular enzyme fermentation |
