Construction and secretory expression of beta-galactosidase gene from Lactobacillus bulgaricus in Lactococcus lactis.
- Author:
Wen ZHANG
1
;
Chuan WANG
;
Cheng Yu HUANG
;
Qian YU
;
Heng Chuan LIU
;
Chao Wu ZHANG
;
Xiao Fang PEI
Author Information
- Publication Type:Journal Article
- MeSH: Base Sequence; DNA Primers; Electrophoresis, Polyacrylamide Gel; Lactobacillus; genetics; Plasmids; beta-Galactosidase; genetics
- From: Biomedical and Environmental Sciences 2012;25(2):203-209
- CountryChina
- Language:English
-
Abstract:
OBJECTIVEThis study is to examine the secretion effects of beta-galactosidase in Lactococcus lactis.
METHODSThe usp45 and beta-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 DH5alpha and L. lactis MG1363. The enzyme activity, gene sequencing, SDS-PAGE and hereditary stability were assessed and studied.
RESULTSThe 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/pMG36e-usp-lacZ in both supernatant and cell samples. Beta-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.
CONCLUSIONThe authors concluded that these new recombinant bacteria well expressed and secreted beta-galactosidase, indicating that the beta-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.
