title: Glutathione-mediated response to acid stress in the probiotic bacterium, Lactobacillus salivarius.
abstract: Lactobacillus salivarius, a probiotic bacterium, encounters acidic conditions in its passage through the gastrointestinal tract of human and animal hosts. We studied the effect of a rapid downshift in extracellular pH from 6.5 to 4 on cell growth. The maximum growth rate was higher in low pH medium with glutathione supplementation than without. Cells developed a GSH-mediated acid-tolerance response and, when grown with 0.5 mM GSH, reached a higher final density than with other conditions. These findings suggest that the increased growth rate is caused by uptake of GSH which acts as a nutrient source as well as having protective functions, allowing for continued growth.
authors.affiliation: Department of Biotechnology, Songdo Technopark, 6F Michuhol Tower, 7-50 Songdo-Dong, Yeonsu-Gu, Incheon, 406-840, Republic of Korea. klee02@empal.com
authors.forename: Kibeom
authors.initials: K
authors.lastname: Lee
authors.forename: Kyungbae
authors.initials: K
authors.lastname: Pi
authors.forename: Eun Bae
authors.initials: EB
authors.lastname: Kim
authors.forename: Beom-Seop
authors.initials: BS
authors.lastname: Rho
authors.forename: Sang-Kee
authors.initials: SK
authors.lastname: Kang
authors.forename: Hong Gu
authors.initials: HG
authors.lastname: Lee
authors.forename: Yun-Jaie
authors.initials: YJ
authors.lastname: Choi
mesh_terms: D000143:Acids / Q000633:toxicity*; D001426:Bacterial Proteins / Q000032:analysis; D018533:Biomass; D003470:Culture Media / Q000737:chemistry; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D007778:Lactobacillus / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D019936:Probiotics; D013312:Stress, Physiological
chemical_list: D000143:Acids; D001426:Bacterial Proteins; D003470:Culture Media; D005978:Glutathione