Simplicispira hankyongi sp. nov., a novel denitrifying bacterium isolated from sludge.

A Gram-stain-negative, facultatively anaerobic, motile, light-yellow, and rod-shaped bacterium, designated as NY-02, was isolated from the sludge of a wastewater treatment plant in Hanam City, Republic of Korea. The comparison of 16S rRNA gene sequences revealed that the strain formed a distinct lineage within the genus Simplicispira and was most closely related to S. suum SC1-8 (99.0%), S. limi EMB325 (98.3%), S. psychrophila LMG 5408 (98.2%), and S. piscis RSG39 (97.4%). Both average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) values between strain NY-02, and its closes type strains [S. suum SC1-8, S. limi EMB325, S. psychrophila LMG 5408, and S. piscis RSG39] were lower than the cut-off (≥ 95-96% for ANI and ≥ 70% for DDH) to define a bacterial species. The genome comprises of 3,709,074 bp with a G + C content of 64.2 mol%. Ubiquinone 8 (Q-8) was the predominant quinone. The major fatty acids were C and summed feature 3 (Cω7c and/or Cω6c), and the major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylethanolamine. The results of the physiological, biochemical, and taxonomic analyses in addition to low ANI and DNA-DNA relatedness values (82.2% and < 34.0%, respectively) indicate that the strain NY-02 represents a novel species of the genus Simplicispira. The name proposed for strain NY-02 (= KACC 19731 = LMG 31165) is Simplicispira hankyongi sp. nov.