Brachymonas moutaii sp. nov., a floc-forming bacterium isolated from a distillery wastewater treatment plant.

A white, Gram-negative, facultatively anaerobic, floc-forming bacterial strain with the ability of nitrate reduction, designated M4Q-1T, was isolated from influent samples of the air flotation tank at a distillery effluent treatment plant. Strain M4Q-1T was found to be a non-motile short rod or coccobacillus, oxidase-positive and catalase-negative. Growth was observed at 16-43 °C (optimum 37-40 °C), pH 4.5-8.0 (optimum 7.0), but not in 1.5% (w/v) NaCl (optimum 0%). The sole respiratory quinone of strain M4Q-1T was ubiquinone-8 (Q-8), and the major polar lipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), aminophospholipid (APL), phosphatidylglycerol (PG), two unknown phospholipid (PL) and one unidentified polar lipid (L). The predominant fatty acids (> 10% of total fatty acids) were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) and C16:0. Strain M4Q-1T exhibited the highest 16S rRNA gene sequence similarity to the type strain of Brachymonas denitrificans AS-P1T (96.90%). Phylogenetic analysis based on 16S rRNA gene sequence and the whole-genome sequences revealed that strain M4Q-1T formed a distinct clade closely neighboring the members of the genus Brachymonas. The G + C content of genomic DNA was 64.5 mol%. Combined with the analyses of the orthologous average nucleotide identities (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH), strain M4Q-1T represented a novel species of the genus Brachymonas, for which the name Brachymonas moutaii sp. nov. is proposed, with the type strain M4Q-1T (= MCCC 1K10055 = KCTC 18263).