Peptide transporter-related protein 2 plays an important role in glutathione transport of Streptococcus thermophilus

Streptococcus thermophilus is widely used as a starter culture in the fermentation of yogurt. Glutathione (GSH; γ-glutamyl-cysteinyl-glycine), tripeptide, has an important physiological role for Strep. thermophilus. However, scope GSH transport proteins still unexplored this species. In present study, 5 peptide transporter-related (Ptrp) strain ST-1 were selected and then inactivated by gene insertion, respectively. Through detection comparison intracellular content mutant wild strain, we identified 2 proteins, named Ptrp-2 Ptrp-4, that might be related to transport. Reverse-transcriptase quantitative PCR was performed verify expressions these possible transport-related it finally determined plays Milk experiments further conducted test effect on characteristics The results showed fermented milk hardly curds using indicating yogurt starter.