Glutathione-mediated response to acid stress in the probiotic bacterium, Lactobacillus salivarius.
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.
Lee
Kibeom
K
Department of Biotechnology, Songdo Technopark, 6F Michuhol Tower, 7-50 Songdo-Dong, Yeonsu-Gu, Incheon, 406-840, Republic of Korea. klee02@empal.com
Pi
Kyungbae
K
Kim
Eun Bae
EB
Rho
Beom-Seop
BS
Kang
Sang-Kee
SK
Lee
Hong Gu
HG
Choi
Yun-Jaie
YJ
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
D000143:Acids; D001426:Bacterial Proteins; D003470:Culture Media; D005978:Glutathione