Tannockella kyphosi gen. nov., sp. nov., a member of the family Erysipelotrichaceae, isolated from the hindgut of the marine herbivorous fish Kyphosus sydneyanus

Abstract

A Gram-stain-positive, non-spore-forming, rod-shaped, obligately anaerobic bacterium, designated strain BP52G^T, was isolated from the hindgut of a Silver Drummer (Kyphosus sydneyanus) fish collected from the Hauraki Gulf, New Zealand. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the isolate belonged to the family Erysipelotrichaceae in the phylum Firmicutes and was most closely related to Clostridium saccharogumia with 93.3 % sequence identity. Isolate BP52G^T grew on agar medium containing mannitol as the sole carbon source. White, opaque and shiny colonies of the isolate measuring approximately 1 mm diameter grew within a week at 20-28 °C (optimum, 24 °C) and pH 6.9-8.5 (optimum, pH 7.8). BP52G^T tolerated the addition of up to 1 % NaCl to the medium. Formate and acetate were the major fermentation products. The major cellular fatty acids were C_{16 : 0}, C_16:1n-7t and C_18:1n-7t. The genome sequence of the isolate was determined. Its G+C content was 30.7 mol%, and the 72.65 % average nucleotide identity of the BP52G^T genome to its closest neighbour with a completely sequenced genome (Erysipelatoclostridium ramosum JCM 1298^T) indicated low genomic relatedness. Based on the phenotypic and taxonomic characteristics observed in this study, a novel genus and species Tannockella kyphosi gen. nov., sp. nov. is proposed for isolate BP52G^T (=NZRM 4757^T=JCM 34692^T).

Keywords: Erysipelotrichaceae; Firmicutes; Tannockella kyphosi; herbivorous fish; hindgut fermenter; seaweed.