RRC ID 2959
著者 Kurdi P, Kawanishi K, Mizutani K, Yokota A.
タイトル Mechanism of growth inhibition by free bile acids in lactobacilli and bifidobacteria.
ジャーナル J Bacteriol
Abstract The effects of the free bile acids (FBAs) cholic acid (CA), deoxycholic acid (DCA), and chenodeoxycholic acid on the bioenergetics and growth of lactobacilli and bifidobacteria were investigated. It was found that these FBAs reduced the internal pH levels of these bacteria with rapid and stepwise kinetics and, at certain concentrations, dissipated DeltapH. The bile acid concentrations that dissipated DeltapH corresponded with the MICs for the selected bacteria. Unlike acetate, propionate, and butyrate, FBAs dissipated the transmembrane electrical potential (DeltaPsi). In Bifidobacterium breve JCM 1192, the synthetic proton conductor pentachlorophenol (PCP) dissipated DeltapH with a slow and continuous kinetics at a much lower concentration than FBAs did, suggesting the difference in mode of action between FBAs and true proton conductors. Membrane damage assessed by the fluorescence method and a viability decrease were also observed upon exposure to CA or DCA at the MIC but not to PCP or a short-chain fatty acid mixture. Loss of potassium ion was observed at CA concentrations more than 2 mM (0.4x MIC), while leakage of other cellular components increased at CA concentrations more than 4 mM (0.8 x MIC). Additionally, in experiments with membrane phospholipid vesicles extracted from Lactobacillus salivarius subsp. salicinius JCM 1044, CA and DCA at the MIC collapsed the DeltapH with concomitant leakage of intravesicular fluorescent pH probe, while they did not show proton conductance at a lower concentration range (e.g., 0.2x MIC). Taking these observations together, we conclude that FBAs at the MIC disturb membrane integrity and that this effect can lead to leakage of proton (membrane DeltapH and DeltaPsi dissipation), potassium ion, and other cellular components and eventually cell death.
巻・号 188(5)
ページ 1979-86
公開日 2006-3-1
DOI 10.1128/JB.188.5.1979-1986.2006
PII 188/5/1979
PMID 16484210
PMC PMC1426545
MeSH Bifidobacterium / drug effects* Bifidobacterium / metabolism Bile Acids and Salts / pharmacology* Cell Membrane / drug effects Cell Membrane / metabolism Chenodeoxycholic Acid / pharmacology Cholic Acid / pharmacology Deoxycholic Acid / pharmacology Hydrogen-Ion Concentration Lactobacillus / drug effects* Lactobacillus / metabolism Membrane Potentials Microbial Sensitivity Tests
IF 3.006
引用数 144
WOS 分野 MICROBIOLOGY
リソース情報
病原微生物 JCM 1034? JCM 1040? JCM 1044? JCM 1047? JCM 1131? JCM 1112? JCM 1231? JCM 1115? JCM 1157? JCM 1192? JCM 7017? JCM 1200? JCM 8224? JCM 1217? JCM 1255? JCM 1275?