Open AccessMarker‐free chromosomal integration of the manganese superoxide dismutase gene ( sodA ) from Streptococcus thermophilus into Lactobacillus gasseri
Author(s) -
BrunoBárcena José M.,
AzcáratePeril M. Andrea,
Klaenhammer Todd R.,
Hassan Hosni M.
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.03.044
Subject(s) - lactobacillus gasseri , streptococcus thermophilus , biology , superoxide dismutase , microbiology and biotechnology , lactobacillus acidophilus , lactobacillus , plasmid , gene , genetics , biochemistry , bacteria , enzyme , probiotic
A strategy for functional gene replacement in the chromosome of Lactobacillus gasseri is described. The phospho‐β‐galactosidase II gene ( lacII ) was functionally replaced by the manganese superoxide dismutase (MnSOD) gene ( sodA ) from Streptococcus thermophilus , by adapting the insertional inactivation method described for lactobacilli [Russell, W.M. and Klaenhammer, T.R. 2001 Efficient system for directed integration into the Lactobacillus acidophilus and Lactobacillus gasseri chromosomes via homologous recombination. Appl. Environ. Microbiol. 67, 4361–4364]. L. gasseri carrying the heterologous sodA gene grew on lactose as efficiently as the wild‐type parent. An active MnSOD was expressed in the transgenic strain, and the enzyme migrated on PAGE‐SOD activity gels to the same position as that of MnSOD from S. thermophilus . The expression of MnSOD from a single copy of sodA integrated in the chromosome of L. gasseri provided enhanced tolerance to hydrogen peroxide, and extended the viability of carbon/energy starved cultures stored at 25 °C. This is the first report showing the successful utilization of the pORI plasmids system to generate marker‐free gene integration in L. gasseri strains.