title: The effect of low pH on protein expression by the probiotic bacterium Lactobacillus reuteri.
abstract: The ability of a lactic acid bacterium to survive passage through the gastrointestinal tract is a key point in its function as a probiotic. In this study, protein synthesis by the probiotic bacterium, Lactobacillus reuteri, was analyzed under transiently decreased pH conditions. L. reuteri cells grown to the midexponential growth phase at 37 degrees C were exposed to transient (1 h) low-pH stresses from pH 6.8 to pH 5.0, 4.5, or 4.0. 2-DE allowed us to identify 40 common proteins that were consistently and significantly altered under all three low-pH conditions. PMF was used to identify these 40 proteins, and functional annotation allowed them to be distributed to six major classes: (i) transport and binding proteins; (ii) transcription-translation; (iii) nucleotide metabolism and amino acid biosynthesis; (iv) carbon energy metabolism; (v) pH homeostasis and stress; and (vi) unassigned. These findings provide new insight into the inducible mechanisms underlying the capacity of gastrointestinal L. reuteri to tolerate acid stress.
authors: Department of Biotechnology, SongDo Techno Park, Incheon, Korea. klee02@empal.com
authors: KiBeom
authors: K
authors: Lee
authors: Hong-Gu
authors: HG
authors: Lee
authors: KyungBae
authors: K
authors: Pi
authors: Yun-Jaie
authors: YJ
authors: Choi
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D006863:Hydrogen-Ion Concentration; D052200:Limosilactobacillus reuteri / Q000254:growth & development / Q000378:metabolism*; D018384:Oxidative Stress; D019936:Probiotics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins