Brassicibacter mesophilus gen. nov., sp nov., a strictly anaerobic bacterium isolated from food industry wastewater

A novel mesophilic, strictly anaerobic bacterium, strain BMT, was isolated from food industry wastewater. The cells were motile, non-spore-forming rods and stained Gram-negative. Growth of strain BMT was observed at 16-44 degrees C (optimum 37 degrees C) and pH 6.0-9.0 (optimum pH 7.5). The NaCl concentration range for growth was 0-8 % (optimum 1.5 %, w/v). Strain BMT was chemo-organotrophic, using a few sugars and amino acids as sole carbon and energy sources. The fermentation products from peptone-yeast extract broth were propionate, formate, acetate, ethanol and isovalerate. Indole, NH3 and H2S were produced from peptone. No respiratory quinones could be detected. The major fatty acids were iso-C-15:0 (39.3 %), iso-C-15:0 dimethyl acetal (10.1 %), anteiso-C-15:0 (7.6 %), C-14:0 (6.1 %) and C-16:0 (5.6 %). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol and a number of unidentified aminoglycolipids, glycolipids and phospholipids. The DNA G + C content was 28.2 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain BMT was related to various genera of the family Clostridiaceae, and its closest relatives were Sporosalibacterium faouarense SOL3f37(T) (94.3 % 16S rRNA gene sequence similarity), Proteiniborus ethanoligenes GW(T) (92.1 %) and Clostridiisalibacter paucivorans 37HS60(T) (92.0 %). In recognition of its distinct phenotypic and genotypic characteristics, isolate BMT is proposed to represent a novel species of a new genus, Brassicibacter mesophilus gen. nov., sp. nov. The type strain of Brassicibacter mesophilus is BMT (=JCM 16868(T) =DSM 24659(T)).