Hominibacterium faecale gen. nov., sp. nov., an anaerobic L-arginine-degrading bacterium isolated from human feces.

Abstract

Two anaerobic, mesophilic bacteria SF3T and ASD5510 were isolated from human feces in two different countries. Strain SF3T shared 99.9% of 16S rRNA gene sequence similarity with strain ASD5510, and 92.8% similarity with the most similar strain Aminipila butyrica DSM 103574T. Strain SF3T was an anaerobic, Gram-stain-positive bacterium. Cells of strain SF3T were short rods with 0.3-0.4µm in width × 2.0-2.4µm in length and occurred mostly in pairs or short chains. Spore formation was not observed. The strain grew optimally at 35°C (range from 20 to 45°C), pH 7.5 (pH 6.0-8.5) and without NaCl addition (range from 0 to 20gl-1 NaCl). Yeast extract was an essential growth factor for strain SF3T, L-arginine and γ-aminobutyrate were utilized as substrates for growth. The major cellular fatty acids were iso-C15:0 and C16:0 DMA. The main polar lipids were aminophospholipid (APL), diphosphatidylglycerol (DPG) and phosphatidylethanolamine (PE). The G + C content of the genomic DNA of the strain SF3T was 47.38mol %. The paired genomic average amino acid identity (AAI) and percentage of conserved proteins (POCP) values showed relatedness of less than 61.0 and 39.4% with type strains of order Eubacteriales. On the basis of phenotypic, phylogenetic and phylogenomic evidence strain SF3T constitutes a novel species in a novel genus, for which the name Hominibacterium faecale gen. nov., sp. nov. is proposed. The type strain is SF3T (= CCAM 730T = JCM 34755T = KCTC 25324T).