Abstract: As one of the important groups of food industry microorganisms, lactic acid bacteria will confront to various abiotic stresses when applied in industry. Previous studies suggested that some lactic acid bacteria can synthesize or absorb glutathione from the medium and protect themselves from diverse stress. In this study, glutathione synthetase gshF from Enterococcus faecalis, which can catalyze the synthesis of glutathione, was cloned and transformed into Lactobacillus paracasei L14 by Lactobacillus recombinant expression vector. The stresses resistance ability of the gshF recombinant strain was evaluated under stress conditions of hydrogen peroxide, acid, freeze-dry dehydration and osmosis. The results suggested that the survival rate of the gshF recombinant strain was greatly improved compare with the control strain.

Key words: Lactobacillus paracasei, Enterococcus faecalis , Glutathione synthetase, gshF , Stress resistance