Aminipila butyrica gen. nov., sp. nov., a strictly anaerobic, arginine-decomposing bacterium isolated from a methanogenic reactor of cattle waste.

A strictly anaerobic bacterial strain (FH042) was isolated from a methanogenic reactor treating waste from cattle farms. Cells were stained Gram-positive, straight to gently curved rods with polar flagella. The strain was asaccharolytic. The strain fermented amino acids (l-arginine, l-lysine and l-serine) as growth substrates and produced acetate and butyrate. The optimum temperature for growth was 30 °C and the optimum pH was 6.1-6.8. Oxidase, catalase and nitrate-reducing activities were negative. Hydrogen sulfide was produced. The genomic DNA G+C content of strain FH042 was 44.7±0.2 mol%. The major cellular fatty acids were C18 : 1ω9c DMA, C17 : 2/C17 : 1ω9c (as summed feature), C16 : 0 DMA and C14 : 0. The cell-wall peptidoglycan contained meso-diaminopimelic acid as a diagnostic amino acid. The most closely related described species on the basis of 16S rRNA gene sequences was Anaerovorax odorimutans in the family XIII Incertae Sedis in the order Clostridiales of the class Clostridia with sequence similarity of 95.1 %. Based on the distinct differences in phylogenetic and phenotypic characteristics between strain FH042 and related species, Aminipila butyrica gen. nov., sp. nov. is proposed to accommodate the strain. Type strain is FH042 (=JCM 31555=DSM 103574).