title: Comparative genome analysis of Lactobacillus reuteri and Lactobacillus fermentum reveal a genomic island for reuterin and cobalamin production.
abstract: Lactobacillus reuteri is a heterofermentative lactic acid bacterium that naturally inhabits the gut of humans and other animals. The probiotic effects of L. reuteri have been proposed to be largely associated with the production of the broad-spectrum antimicrobial compound reuterin during anaerobic metabolism of glycerol. We determined the complete genome sequences of the reuterin-producing L. reuteri JCM 1112(T) and its closely related species Lactobacillus fermentum IFO 3956. Both are in the same phylogenetic group within the genus Lactobacillus. Comparative genome analysis revealed that L. reuteri JCM 1112(T) has a unique cluster of 58 genes for the biosynthesis of reuterin and cobalamin (vitamin B(12)). The 58-gene cluster has a lower GC content and is apparently inserted into the conserved region, suggesting that the cluster represents a genomic island acquired from an anomalous source. Two-dimensional nuclear magnetic resonance (2D-NMR) with (13)C(3)-glycerol demonstrated that L. reuteri JCM 1112(T) could convert glycerol to reuterin in vivo, substantiating the potential of L. reuteri JCM 1112(T) to produce reuterin in the intestine. Given that glycerol is shown to be naturally present in feces, the acquired ability to produce reuterin and cobalamin is an adaptive evolutionary response that likely contributes to the probiotic properties of L. reuteri.
authors.affiliation: School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan. morita@azabu-u.ac.jp
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Morita
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Toh
authors.forename: Shinji
authors.initials: S
authors.lastname: Fukuda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Horikawa
authors.forename: Kenshiro
authors.initials: K
authors.lastname: Oshima
authors.forename: Takehito
authors.initials: T
authors.lastname: Suzuki
authors.forename: Masaru
authors.initials: M
authors.lastname: Murakami
authors.forename: Shin
authors.initials: S
authors.lastname: Hisamatsu
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kato
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Takizawa
authors.forename: Hideo
authors.initials: H
authors.lastname: Fukuoka
authors.forename: Tetsuhiko
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Kikuji
authors.initials: K
authors.lastname: Itoh
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: O'Sullivan
authors.forename: Larry L
authors.initials: LL
authors.lastname: McKay
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohno
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
authors.forename: Toshio
authors.initials: T
authors.lastname: Masaoka
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
mesh_terms: D002874:Chromosome Mapping; D016680:Genome, Bacterial; D044404:Genomic Islands; D005985:Glyceraldehyde / Q000031:analogs & derivatives* / Q000378:metabolism; D052197:Limosilactobacillus fermentum / Q000235:genetics* / Q000378:metabolism; D052200:Limosilactobacillus reuteri / Q000235:genetics* / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D008954:Models, Biological; D005810:Multigene Family; D010802:Phylogeny; D011407:Propane / Q000378:metabolism*; D014805:Vitamin B 12 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C047158:3-hydroxypropionaldehyde; D005985:Glyceraldehyde; D014805:Vitamin B 12; D011407:Propane