Propioniciclava tarda gen. nov., sp. nov., isolated from a methanogenic reactor treating waste from cattle farms

Abstract

Two facultatively anaerobic bacterial strains, designated WR061Tand WR054, were isolated from rice-straw residue in a methanogenic reactor treating waste from cattle farms in Japan. The two strains were phylogenetically positioned close to one another and had almost the same phenotypic properties. Cells were Gram-reaction-positive, non-motile, non-spore-forming, irregular rods. Cobalamin (vitamin B12) was required for growth. The strains utilized various carbohydrates, including hexoses and disaccharides, and produced acetate and propionate from these carbohydrates. Pentoses and polysaccharides were not utilized. They grew at 20–37 °C (optimum 35 °C) and pH 5.3–8.0 (optimum pH 6.8–7.5). Catalase and nitrate-reducing activities were detected. Aesculin was hydrolysed. The major cellular fatty acids were anteiso-C15 : 0and C15 : 0DMA, the major respiratory quinone was menaquinone MK-9(H4) and the genomic DNA G+C content was 69.3–69.5 mol%. The diagnostic diamino acid in the peptidoglycan wasmeso-diaminopimelic acid. Phylogenetic analysis based on 16S rRNA gene sequences placed the strains in the phylumActinobacteria. Both strains were remotely related to the species in the familyPropionibacteriaceaeandPropionibacterium propionicumJCM 5830Twas the most closely related type strain with a sequence similarity of 91.6 %. Based on phylogenetic, physiological and chemotaxonomic analyses, the two novel strains together represent a novel species of a new genus, for which the namePropioniciclava tardagen. nov., sp. nov. is proposed. The type strain is WR061T( = JCM 15804T = DSM 22130T).