Phylogenetic and phenotypic evidence for the transfer of Eubacterium aerofaciens to the genus Collinsella as Collinsella aerofaciens gen. nov., comb. nov

Japan Collection of Microorganisms, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, 3510198, Japan ABSTRACT Three strains of Eubacterium aerofaciens , JCM 10188 T , JCM 7790 and JCM 7791 and 178 freshly isolated strains of the Eubacterium aerofaciens group from human faeces were characterized by biochemical tests, cell wall peptidoglycal type and 16S rRNA analysis. The Eubacterium aerofaciens group was divided into four groups by fermentation patterns of sucrose and cellobiose, and were further divided into 16 sub-groups by fermentation patterns of aesculin, salici and amygdalin. All of the strains of the Eubacterium aerofaciens group were shown to be phylogenetically distantly related to Eubacterium limosum , which is the type species of genus Eubacterium. Eubacterium aerofaciens was shown to have a specific phylogenetic association with Coriobacterium glomerans. A the strains belonging to Eubacterium aerofaciens resembled Coriobacterium glomerans in possessing a high G+C content (60 mol%). Cell wall analysis, however, revealed the presence of different A4β (L-Ala)-D-Glu- L -Orn- L -Asp peptidoglycan types. Based on a 16S rRNA sequence divergence of greater than 9% with Coriobacterium glomerans and the presence of a unique peptidoglycan type, a new genus, Collinsella , is proposed for Eubacterium aerofaciens , with one species, Collinsella aerofaciens . The type strain of Collinsella aerofaciens is JCM 10188 T . Key Words: Collinsella aerofaciens gen. nov. • comb. nov. • Eubacterium aerofaciens • 16S rDNA • cell wall The GenBank/EMB/DDBJ accession numbers for the sequences determined in this paper are AB011814 (Eubacterium aerofaciens JCM 7790), AB011815 (JCM 7791) and AB011816 (JCM 10188 T ).