南京林业大学学报(自然科学版) ›› 2015, Vol. 39 ›› Issue (06): 35-39.doi: 10.3969/j.issn.1000-2006.2015.06.007

• 研究论文 • 上一篇    下一篇

凝结芽孢杆菌中β-半乳糖苷酶基因的克隆及表达

郑兆娟,徐 颖,石 磊,欧阳嘉*   

  1. 南京林业大学化学工程学院,江苏省生物质绿色燃料与化学品重点实验室,江苏 南京 210037
  • 出版日期:2015-11-30 发布日期:2015-11-30
  • 基金资助:
    收稿日期:2015-03-25 修回日期:2015-08-25
    基金项目:国家自然科学基金青年基金项目(31300487, 31200443); 江苏省自然科学基金青年项目(BK20130970); 江苏高校优势学科建设工程资助项目(PAPD)
    第一作者:郑兆娟,讲师,博士。*通信作者:欧阳嘉,教授。E-mail:hgouyj@njfu.edu.cn。
    引文格式:郑兆娟,徐颖,石磊,等. 凝结芽孢杆菌中β-半乳糖苷酶基因的克隆及表达[J]. 南京林业大学学报:自然科学版,2015,39(6):35-39.

Molecular cloning and expression of a novel β-galactosidase from Bacillus coagulans

ZHENG Zhaojuan, XU Ying, SHI Lei, OUYANG Jia*   

  1. College of Chemical Engineering, Nanjing Forestry University, Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing 210037, China
  • Online:2015-11-30 Published:2015-11-30

摘要: 从1株快速水解乳糖发酵产酸的凝结芽孢杆菌NL01的基因组上克隆获得了1个新的β-半乳糖苷酶基因,该基因长度为1 998 bp,其编码的氨基酸序列与已经报道的β-半乳糖苷酶相似度低于40%。将该β-半乳糖苷酶基因整合到表达载体pETDuet-1上,并在大肠杆菌BL21(DE3)中进行重组表达,β-半乳糖苷酶粗酶酶活为119.0 μmol/(min·mg),经镍柱纯化获得的重组β-半乳糖苷酶酶活为666.4 μmol/(min·mg)。利用该重组β-半乳糖苷酶水解乳糖,经TLC和HPLC分析显示该酶具有将乳糖水解为葡萄糖和半乳糖的活力,是一种新型的β-半乳糖苷酶。

Abstract: A novel β-galactosidase gene was cloned from Bacillus coagulans NL01 which had ability to hydrolyze lactose into glucose and galactose in this study. The length of the β-galactosidase gene was 1 998 bp, and its coding sequence showed very low identity with other reported β-galactosidase. The gene was cloned into pETDuet-1 and expressed in Escherichia coli BL21(DE3). The crude enzyme activity was 119.0 μmol/(min·mg), and the purified enzyme activity was 666.4 μmol/(min·mg)after Ni-NTA purification. It was indicated from the analysis results of the hydrolysis product obtained by the purified β-galactosidase that this novel β-galactosidase presented high activity toward lactose conversion into glucose and galactose.

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