Construction and Secretory Expression of β-Galactosidase Gene from Lactobacillus Bulgaricus in Lactococcus Lactis  

作　　者：ZHANG Wen WANG Chuan HUANG Cheng Yu YU Qian LIU Heng Chuan ZHANG Chao Wu PEI Xiao Fang 

机构地区：[1]Department of Nutrition and Food Hygiene, West China School of Public Health, Sichuan University, Chengdu 610041, Sichuan, China [2]Department of Medical Technology, West China School of Public Health, Sichuan University, Chengdu 610041, Sichuan, China [3]Central Hospital of Sichuan Petroleum Bureau, Chengdu 610213, Sichuan, China

出　　处：《Biomedical and Environmental Sciences》2012年第2期203-209,共7页生物医学与环境科学（英文版）

基　　金：supported by the National Science Foundation of China (NO. 30800910)

摘　　要：Objective This study is to examine the secretion effects of β-galactosidase in Lactococcus lactis.Methods The usp45 and β-galactosidase genes were cloned and inserted into plasmid pMG36e to obtain the recombinant plasmid pMG36e-usp-lacZ.This recombinant plasmid was transformed into both Escherichia coli DH5α and L.lactis MG1363.The enzyme activity,gene sequencing,SDS-PAGE and hereditary stability were assessed and studied.Results The lacZ gene inserted into plasmids pMG36e-usp-lacZ was 99.37% similar to the GenBank sequence,and SDS-PAGE revealed an evident idio-strap at 116 KDa between L.lactis MG1363/pMG36eusp-lacZ in both supernatant and cell samples.β-Galactosidase activity measured 0.225 U/mL in L.lactis pMG36e-usp-lacZ transformants,and its secretion rate was 10%.The plasmid pMG36e-usp-lacZ appeared more stable in MG1363.Conclusion The authors concluded that these new recombinant bacteria well expressed and secreted β-galactosidase,indicating that the β-galactosidase expression system was successfully constructed,and this might provide a new solution for management of lactose intolerance specifically and promote the use of gene-modified organisms as part of the food-grade plasmid in general.

关 键 词：Gene constructs Gene expression Secretory expression Β-GALACTOSIDASE Lactococcus lactis 

分 类 号：Q78[生物学—分子生物学] TS202.3[轻工技术与工程—食品科学]