Simplicispira lacusdiani sp. nov., a novel betaproteobacterium isolated from a freshwater reservoir.

A Gram-stain-negative, motile, rod-shaped bacterium, designated CPCC 100842, was isolated from a freshwater reservoir in south-west China. The 16S rRNA gene sequence comparison of strain CPCC 100842 with the available sequences in the GenBank database showed that the isolate was closely related to members of the family Comamonadaceae, with the highest similarities to Simplicispira metamorpha DSM 1837 (98.05 %), Simplicispira limi KCTC 12608 (97.86 %), Simplicispira psychrophila LMG 5408 (97.04 %) and Simplicispira piscis JCM 19291 (97.0 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 100842 formed a distinct phylogenetic subclade within the genus Simplicispira. The major cellular fatty acids were as C16 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1ω6c). Q-8 was detected as the only respiratory quinone. Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid and glycolipid were found in the polar lipid extraction. The genomic DNA G+C content was 67.4 mol%. The average nucleotide identity value was 80.4 % by comparing the draft genome sequences of strain CPCC 100842 and S. metamorpha DSM 1837. The DNA-DNA hybridization result between strain CPCC 100842 and S. metamorpha DSM 1837 showed 37±3 % genomic relatedness. On the basis of the genotypic analysis and phenotypic characteristics, we propose that strain CPCC 100842 represents a novel species of the genus Simplicispira in the family Comamonadaceae with the name Simplicispira lacusdiani sp. nov. Strain CPCC 100842 (=KCTC 52093=DSM 102231) is the type strain of the species.