Study of the baiG Gene in Bile Acid 7α-Dehydroxylating Bacteria

• Main Author: David, Michael
• Format: Others
• Published: TopSCHOLAR® 1999
• Subjects: Biology
• Online Access: http://digitalcommons.wku.edu/theses/747; http://digitalcommons.wku.edu/cgi/viewcontent.cgi?article=1750&context=theses

Recently, intestinal bile acid 7α-dehydroxylating bacteria have been implicated in cholesterol gallstone disease. Eubacterium sp. strain V.P.I. 12708, a bile acid 7α-dehydroxylating bacteria, contains multiple bile acid inducible (bai) genes which are located on a large bai operon. Genes of this operon encode the enzymes responsible for bile acid 7α-dehydroxylation. The baiG gene encodes a bile acid transporter in Eubacterium sp. strain V.P.I. 12708. Utilizing the polymerase chain reaction I determined the presence or absence of baiG-like genes in six bile acid 7α-dehydroxylating strains: Clostridium sp. Strain TN-271, Eubacterium sp. strain 1-10, Clostridium bifermentans strain 1-55, Clostridium sordellii strain Y67, Clostridium sp. strain HD-17, and Clostridium sp. strain TO-931. Results showed amplification in two of the bacterial strains at the predicted DNA fragment size. Partial DNA sequence analysis of the amplified baiG-like gene fragments revealed 96-97% homology with the baiG gene of Eubacterium sp. strain V.P.I. 12708. These data suggest that baiG-like genes are present in Clostridium sp. strain TN-271 and Eubacterium sp. strain I-10.