Morita Hidetoshi, Toh Hidehiro, Fukuda Shinji, Horikawa Hiroshi, Oshima Kenshiro, Suzuki Takehito, Murakami Masaru, Hisamatsu Shin, Kato Yukio, Takizawa Tatsuya, Fukuoka Hideo, Yoshimura Tetsuhiko, Itoh Kikuji, O'Sullivan Daniel J, McKay Larry L, Ohno Hiroshi, Kikuchi Jun, Masaoka Toshio, Hattori Masahira
School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan.
DNA Res. 2008 Jun 30;15(3):151-61. doi: 10.1093/dnares/dsn009. Epub 2008 May 16.
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.
罗伊氏乳杆菌是一种异源发酵乳酸菌，自然栖息于人类和其他动物的肠道中。有人提出，罗伊氏乳杆菌的益生菌作用在很大程度上与甘油厌氧代谢过程中产生的广谱抗菌化合物罗伊菌素有关。我们测定了产罗伊菌素的罗伊氏乳杆菌JCM 1112(T)及其密切相关物种发酵乳杆菌IFO 3956的全基因组序列。两者都属于乳杆菌属中的同一系统发育组。比较基因组分析表明，罗伊氏乳杆菌JCM 1112(T)有一个由58个基因组成的独特簇，用于罗伊菌素和钴胺素（维生素B12）的生物合成。这个58个基因的簇GC含量较低，显然插入到保守区域，表明该簇代表了从异常来源获得的一个基因组岛。用(13)C(3)-甘油进行的二维核磁共振（2D-NMR）表明，罗伊氏乳杆菌JCM 1112(T)能够在体内将甘油转化为罗伊菌素，证实了罗伊氏乳杆菌JCM 1112(T)在肠道中产生罗伊菌素的潜力。鉴于甘油被证明天然存在于粪便中，获得的产生罗伊菌素和钴胺素的能力是一种适应性进化反应，可能有助于罗伊氏乳杆菌的益生菌特性。
