Improved Cell Viability and Anti-Candida Activity of Probiotic Lactobacillus salivarius MG242 by Heat Adaptation

Vulvovaginal candidiasis is a major urogenital infection in women. Lactobacilli are important in maintaining vaginal health. In the present study, the effect of heat adaptation at 47∼52°C prior to heat stress at 60°C in improving the viability of Lactobacillus salivarius MG242 was examined. L. salivarius MG242 has antifungal effects against Candida albicans. Heat-adapted cells had a higher survival rate than non-adapted cells during the subsequent heat stress. When chloramphenicol was added during the adaptation process, heat tolerance was abolished, suggesting the involvement of de novo protein synthesis with the heat adaptation of L. salivarius MG242 strain. Exopolysaccharide quantification and scanning election microscopy did not reveal any appreciable changes during heat adaptation. The antifungal activity of L. salivarius MG242 against C. albicans was maintained during the heat adaptation. These results suggest that heat adaptation can be applied for the development of probiotic products using L. salivarius MG242 to improve its stress tolerance during processing.