Pseudomonas caeni sp. nov., a denitrifying bacterium isolated from the sludge of an anaerobic ammonium-oxidizing bioreactor

Abstract

Two Gram-negative, rod-shaped, motile, aerobic bacterial strains designated HY-14T and HY-24 were isolated from the sludge of an anaerobic ammonium-oxidizing bioreactor. The strains could not grow with 5% (w/v) NaCl, did not produce acid from D-glucose or utilize D-glucose, gluconate or citrate as a sole carbon source. Summed feature 3 and C16:0 were the most abundant fatty acids; hydroxyl fatty acids C12:0 3-OH and C10:0 3-OH were also present. Fatty acid C12:0 2-OH was absent. The DNA G+C contents of strains HY-14T and HY-24 were 50.6±0.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains HY-14T and HY-24 formed a monophyletic clade within the genus Pseudomonas. The highest sequence similarities were to Pseudomonas pseudoalcaligenes DSM 50188T (95.9%). On the basis of phenotypic and phylogenetic properties, strains HY-14T and HY-24 are proposed as a novel species of the genus Pseudomonas, for which the name Pseudomonas caeni sp. nov. is proposed. The type strain is HY-14T (=KCTC 22292T=CCTCC AB208156T).