HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Elkins, C. A. Articles by Savage, D. C. Search for Related Content PubMed PubMed Citation Articles by Elkins, C. A. Articles by Savage, D. C. Agricola Articles by Elkins, C. A. Articles by Savage, D. C.

Genes encoding bile salt hydrolases and conjugated bile salt transporters in Lactobacillus johnsonii 100-100 and other Lactobacillus species

Department of Microbiology, M409 Walters Life Sciences Bldg, University of Tennessee, Knoxville, TN 37996-0845, USA¹

Author for correspondence: Dwayne C. Savage. Tel: +1 865 974 4015. Fax: +1 865 974 4007. e-mail: Dsavage1{at}utk.edu

Lactobacillus johnsonii strain 100-100 expresses two antigenically distinct conjugated bile salt hydrolases (BSH), and ß, that combine to form native homo- and heterotrimers. This paper reports characterization of loci within the genome that encode this capacity. A locus that encodes BSHß (cbsHß), a partial (cbsT1) and a complete conjugated bile salt transporter (cbsT2) was identified previously. DNA sequence analysis at this locus was extended and revealed a complete ORF for cbsT1 and no other ORFs in tandem. The three genes, cbsT1, cbsT2 and cbsHß, probably constitute an operon; a putative promoter was identified upstream of cbsT1. A second locus that expresses BSH activity in strain 100-100 was identified. Sequence analysis of the clone predicted a 978 nt ORF that did not share tandem organization with other ORFs, was similar in sequence to other BSH genes, and matched, in predicted protein sequence, the first 25 amino acids of BSH. A phenotypic screen for BSH activity and a genetic screen for the cbsHß locus were performed on 50 Lactobacillus isolates from humans or dairy products. Nearly all of the isolates that were positive for cbsHß were from human sources. Variability in the BSH phenotype and cbsHß genotype was identified in isolates of the same species. DNA sequence was obtained and analysed from the cbsHß locus of one human isolate, L. acidophilus strain KS-13. This organism has cbsT1, cbsT2 and cbsß genes that are 84, 87 and 85% identical in DNA sequence to those of strain 100-100. DNA sequence identity to strain 100-100 ends in regions flanking this locus. The findings of this study suggest that BSH genes have been acquired horizontally and that BSH activity is important at some level for lactobacilli to colonize the lower gastrointestinal tract.

Keywords: intestinal microflora, probiotics, major facilitator superfamily, horizontal gene transfer, lactic acid bacteria

Abbreviations: BSH, bile salt hydrolase; EF, extracellular factor; LDGW, long-distance genome walking; LPEA, long primer extension and amplification; MFS, major facilitator superfamily

The GenBank accession numbers for the sequences determined in this work are AF054971, AF091248 (sequences of the complete BSH operons in L. johnsonii strain 100-100 and L. acidophilus strain KS-13, respectively) and AF297873 (sequence of cbsH).

This article has been cited by other articles:

				M. A. Azcarate-Peril, E. Altermann, Y. J. Goh, R. Tallon, R. B. Sanozky-Dawes, E. A. Pfeiler, S. O'Flaherty, B. L. Buck, A. Dobson, T. Duong, et al. Analysis of the Genome Sequence of Lactobacillus gasseri ATCC 33323 Reveals the Molecular Basis of an Autochthonous Intestinal Organism Appl. Envir. Microbiol., August 1, 2008; 74(15): 4610 - 4625. [Abstract] [Full Text] [PDF]

				B. Sanchez, M.-C. Champomier-Verges, B. Stuer-Lauridsen, P. Ruas-Madiedo, P. Anglade, F. Baraige, C. G. de los Reyes-Gavilan, E. Johansen, M. Zagorec, and A. Margolles Adaptation and Response of Bifidobacterium animalis subsp. lactis to Bile: a Proteomic and Physiological Approach Appl. Envir. Microbiol., November 1, 2007; 73(21): 6757 - 6767. [Abstract] [Full Text] [PDF]

				M. Begley, C. Hill, and C. G. M. Gahan Bile salt hydrolase activity in probiotics. Appl. Envir. Microbiol., March 1, 2006; 72(3): 1729 - 1738. [Full Text] [PDF]

				B. Sanchez, M.-C. Champomier-Verges, P. Anglade, F. Baraige, C. G. de los Reyes-Gavilan, A. Margolles, and M. Zagorec Proteomic Analysis of Global Changes in Protein Expression during Bile Salt Exposure of Bifidobacterium longum NCIMB 8809 J. Bacteriol., August 15, 2005; 187(16): 5799 - 5808. [Abstract] [Full Text] [PDF]

				M. Begley, R. D. Sleator, C. G. M. Gahan, and C. Hill Contribution of Three Bile-Associated Loci, bsh, pva, and btlB, to Gastrointestinal Persistence and Bile Tolerance of Listeria monocytogenes Infect. Immun., February 1, 2005; 73(2): 894 - 904. [Abstract] [Full Text] [PDF]

				C. A. Elkins and L. B. Mullis Bile-Mediated Aminoglycoside Sensitivity in Lactobacillus Species Likely Results from Increased Membrane Permeability Attributable to Cholic Acid Appl. Envir. Microbiol., December 1, 2004; 70(12): 7200 - 7209. [Abstract] [Full Text] [PDF]

				R. D. Pridmore, B. Berger, F. Desiere, D. Vilanova, C. Barretto, A.-C. Pittet, M.-C. Zwahlen, M. Rouvet, E. Altermann, R. Barrangou, et al. The genome sequence of the probiotic intestinal bacterium Lactobacillus johnsonii NCC 533 PNAS, February 24, 2004; 101(8): 2512 - 2517. [Abstract] [Full Text] [PDF]

				P. Kurdi, H. Tanaka, H. W. van Veen, K. Asano, F. Tomita, and A. Yokota Cholic acid accumulation and its diminution by short-chain fatty acids in bifidobacteria Microbiology, August 1, 2003; 149(8): 2031 - 2037. [Abstract] [Full Text] [PDF]