Caenimonas sedimenti sp. nov., Isolated from Sediment of the Wastewater Outlet of an Agricultural Chemical Plant

Abstract

A novel bacterial strain, designated HX-9-20^T, was isolated from the sediment collected from the wastewater outlet of an agricultural chemical plant in Maanshan city, Anhui province, PR China. Cells of strain HX-9-20^T were Gram-staining-negative, rod-shaped, translucent, non-motile, and strictly aerobic. Growth was observed between 15 and 35 °C (optimum 30 °C), at pH 6.0-8.0 (optimum pH 7.0), and in the presence of 0-0.4% (w/v) NaCl (optimum 0.2%). The predominant cellular fatty acids were summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c), C_16:0 and summed feature 8 (C_18:1 ω6c and/or C_18:1 ω7c). The major quinone was ubiquinone Q-8. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, and an aminophospholipid. Strain HX-9-20^T contains 2-hydroxyputrescine and putrescine as the major polyamine. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HX-9-20^T was affiliated with the genus Caenimonas, exhibiting the highest sequence similarities with Caenimonas koreensis EMB320^T (97.3% similarity) and Ramlibacter humi 18×22-1^T (97.0%), and less than 97.0% similarity with other type strains. The average nucleotide identity (ANI) and digital DNA-DNA hybridization values (dDDH) between HX-9-20^T and C. koreensis EMB320^T were 76.9% and 23.5% respectively. The ANI and dDDH between HX-9-20^T and R. humi 18×22-1^T were 80.3% and 23.6%, respectively. The G + C content of the genomic DNA was 67.5 mol%. On the basis of the polyphasic taxonomic data, strain HX-9-20^T represents a novel species of the genus Caenimonas, for which the name Caenimonas sedimenti sp. nov. is proposed. The type strain is HX-9-20^T (=KCTC 72473^T=CCTCC AB 2019266^T).