Cloning and characterization of a bile salt hydrolase (bsh) from Bifidobacterium adolescentis

Kim, Geun‐Bae; Brochet, Mathieu; Lee, Byong H.

doi:10.1007/s10529-005-6717-3

Cited by 39 publications

(26 citation statements)

References 30 publications

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“…This enzyme is present in many bacterial species of the gastrointestinal tract and catalyzes the release of the amino acid moiety from the conjugated bile salt, rendering deconjugated bile acids. Its activity is one of the positive factors for probiotic selection (3), and its function has been extensively studied (6,11,23,24,47), but its physiological role in probiotic bacteria remains unclear. Deconjugated bile salts are more toxic than the conjugated ones for Bifidobacterium (18,33), due to their higher detergent activity.…”

Section: Discussionmentioning

confidence: 99%

Low-pH Adaptation and the Acid Tolerance Response of Bifidobacterium longum Biotype longum

Sánchez

Champomier‐Vergès²,

Collado

et al. 2007

Appl Environ Microbiol

179

154

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Bifidobacteria are one of the main microbial inhabitants of the human colon. Usually administered in fermented dairy products as beneficial microorganisms, they have to overcome the acidic pH found in the stomach during the gastrointestinal transit to be able to colonize the lower parts of the intestine. The mechanisms underlying acid response and adaptation in Bifidobacterium longum biotype longum NCIMB 8809 and its acid-pH-resistant mutant B. longum biotype longum 8809dpH were studied. Comparison of protein maps, and protein identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, allowed us to identify nine different proteins whose production largely changed in the mutant strain. Furthermore, the production of 47 proteins was modulated by pH in one or both strains. These included general stress response chaperones and proteins involved in transcription and translation as well as in carbohydrate and nitrogen metabolism, among others. Significant differences in the levels of metabolic end products and in the redox status of the cells were also detected between the wild-type strain and its acid-pHresistant mutant in response to, or as a result of, adaptation to acid. Remarkably, the results of this work indicated that adaptation and response to low pH in B. longum biotype longum involve changes in the glycolytic flux and in the ability to regulate the internal pH. These changes were accompanied by a higher content of ammonium in the cytoplasm, likely coming from amino acid deamination, and a decrease of the bile salt hydrolase activity.

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Section: Discussionmentioning

confidence: 99%

Low-pH Adaptation and the Acid Tolerance Response of Bifidobacterium longum Biotype longum

Sánchez

Champomier‐Vergès²,

Collado

et al. 2007

Appl Environ Microbiol

179

154

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“…bifidum (18), Bi. adolescentis (19), and Listeria monocytogenes (20,21). Homologs and putative bsh genes have also been identified recently through microbial genome analysis.…”

Section: Characteristics Of Bile Salt Hydrolase(s)mentioning

confidence: 99%

Bile salt biotransformations by human intestinal bacteria

Ridlon

Kang

Hylemon

2006

Journal of Lipid Research

2,272

2,417

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Secondary bile acids, produced solely by intestinal bacteria, can accumulate to high levels in the enterohepatic circulation of some individuals and may contribute to the pathogenesis of colon cancer, gallstones, and other gastrointestinal (GI) diseases. Bile salt hydrolysis and hydroxy group dehydrogenation reactions are carried out by a broad spectrum of intestinal anaerobic bacteria, whereas bile acid 7-dehydroxylation appears restricted to a limited number of intestinal anaerobes representing a small fraction of the total colonic flora. Microbial enzymes modifying bile salts differ between species with respect to pH optima, enzyme kinetics, substrate specificity, cellular location, and possibly physiological function. Crystallization, site-directed mutagenesis, and comparisons of protein secondary structure have provided insight into the mechanisms of several bile acid-biotransforming enzymatic reactions. Molecular cloning of genes encoding bile salt-modifying enzymes has facilitated the understanding of the genetic organization of these pathways and is a means of developing probes for the detection of bile salt-modifying bacteria. The potential exists for altering the bile acid pool by targeting key enzymes in the 7a/b-dehydroxylation pathway through the development of pharmaceuticals or sequestering bile acids biologically in probiotic bacteria, which may result in their effective removal from the host after excretion.-Ridlon, J. M., D-J. Kang, and P. B. Hylemon. Bile salt biotransformations by human intestinal bacteria. J. Lipid Res. 2006. 47: 241-259.

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“…BSH activity has been detected in Lactobacillus (2,13,18,21,23,30,31,39,60,61,66,72,88,90,91), Bifidobacterium (40,41,50,51,52,89), Enterococcus (34,55,106), Clostridium (14,72), and Bacteroides (48,85) spp. Lactobacilli and bifidobacteria are routinely used as probiotic strains, while Bacteroides, Clostridium, and Enterococcus spp.…”

Section: Incidence Of Bsh Activity Among Bacteriamentioning

confidence: 99%