Abstract

White and pale yellow coloured bacteria were isolated from the riverside soil, Daejeon, South Korea, and were designated UCM-11T, UCM-F25, and UCM-80T. We found that all strains were able to reduce nitrate, and the cells were aerobic and motile. The DNA G+C contents of UCM-11T, UCM-F25, and UCM-80T were between 68.9 to 71.2 mol% and the main ubiquinone was observed as Q-8. Based on16S rRNA gene sequences, strains UCM-11T and UCM-F25 were found to closely match with Azohydromonas australica IAM 12664T (98.48–98.55%), and the strain UCM-80T was the closest match with Azohydromonas lata IAM 12599T (98.34%). The presence of summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:0, summed feature 8 (C18:1ω7c and/or C18:1ω6c) as well as twokinds of hydroxyfatty acids consisting of C10:0 3-OH and C12:0 2-OH, and branched fatty acids containing C16:0 iso and C17:0 cyclo were detected in all the strains. Phosphatidy-lethanolamine was a major polar lipid. DNA–DNA related-ness confirmed UCM-11T, UCM-F25 and UCM-80T as novel members of the genus Azohydromonas. Based on the mor-phological, physiological, biochemical and genotypic char-acteristics, we suggest that strains UCM-11T, UCM-F25, and UCM-80T represent novel species within the genus Azohy-dromonas. The names Azohydromonas riparia sp. nov., and Azohydromonas ureilytica sp. nov. are proposed for the type strains UCM-11T (=KACC 18570T =NBRC 111646T) and UCM-80T (=KACC 18576T =NBRC 111658T), respectively.

• Keywords: Azohydromonas riparia sp. nov.; Azohydromonas ureilytica sp. nov.; taxonomy; Proteobacteria; soil