Pseudokordiimonas caeni gen. nov., sp. nov., isolated from activated sludge

A bacterial strain designated as LB -31T was isolated from activated sludge. Strain LB -31T was Gram- stain-negative, non- spore-forming and rod-shaped with a single polar flagellum. The isolate grew at 15-37 degrees C, pH 5.5-8.5 and 0.5-8.5 % (w/v) NaCl. Genome sequencing revealed a genome size of 3.55 Mb, a G+C content of 61.1 mol% and 3222 protein-coding genes. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LB -31T formed a phyletic lineage that was distinct from the three known genus within the family Kordiimonadaceae. The 16S rRNA gene sequence similarity of strain LB -31T to all recognized bacterial species was no more than 94 %. Average nucleotide identity and digital DNA-DNA hybridization values between strain LB -31T and its phylogenetic neighbours were below 72 and 22 %, respectively. The average amino acid identity values for strain LB -31T and its closed phylogenetic neighbours Kordiimonas and Eilatimonas were below 63%, sup-porting that strain LB -31T was a member of a novel genus. The predominant respiratory quinone is Q-10, the fatty acid profile predominantly consisted of iso- C17: 1 omega 9c, iso-C17:0, iso-C15: 0 and summed feature 3 (comprising iso-C15:02-OH/C16: 1 omega 7c), and the major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The combined genotypic and phenotypic data show that strain LB -31T represents a novel species of a novel genus in the family Kordiimonadaceae, for which the name Pseudokordiimonas caeni gen. nov., sp. nov. is proposed. The type strain of Pseudokordiimonas caeni is LB -31T (=GDMCC 1.3625T=KCTC 92687T).