Zavarzinia aquatilis sp. nov., isolated from a freshwater river.

A Gram-stain-negative, strictly aerobic, catalase-positive and oxidase-positive bacterium, designated strain HR-AS, was isolated from a water sample of the Han River located in the Republic of Korea. Cells were motile rods with a polar flagellum. Growth was observed at 5-35 °C (optimum of 25 °C) and pH 6-8 (optimum of pH 7) and in the presence of 0-2 % (w/v) NaCl (optimum of 0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HR-AS formed a tight phylogenic lineage with Zavarzinia compransoris LMG 5821. Strain HR-AS was most closely related to Z. compransoris LMG 5821 with a 98.7 % 16S rRNA gene sequence similarity and had very low similarities (below 91.0 %) to other type strains with validly published names. Average nucleotide identity and in silico DNA-DNA hybridization values between strain HR-AS and Z. compransoris DSM 1231 were 80.4 and 23.1 %, respectively. Strain HR-AS contained ubiquinone-10 as the major quinone and homospermidine and putrescine as the major polyamines. The major fatty acids were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C16 : 0 and C18 : 1 2-OH. Strain HR-AS contained diphosphatidylglycerol, an unidentified aminolipid and two unidentified phospholipids as major polar lipids. The DNA G+C content of strain HR-AS was 67.2 mol%. Based on the genotypic, chemotaxonomic and phenotypic analyses, strain HR-AS represents a novel species of the genus Zavarzinia, for which the name Zavarziniaaquatilis sp. nov. is proposed. The type strain is HR-AS (=KACC 19412=JCM 32263).