Ottowia caeni sp. nov., a novel phenylacetic acid degrading bacterium isolated from sludge

A novel bacterium, designated BD-1(T), was isolated from a sludge sample. Cells of the novel Gram-stain-negative strain were identified to be facultative anaerobic, non-motile and short rod-shaped. Growth occurred at 15-37 degrees C (optimum, 30 degrees C), pH 5.0-10.0 (pH 7.0) and in 0-4.0 % NaCl (2.0%, w/v). The 16S rRNA gene sequence of strain BD-1(T) showed the highest sequence similarity to Ottowia thiooxydans DSM 14619(T) (97.0%), followed by Ottowia pentelensis DSM 21699(T) (96.3%) and less than 96 % to other related strains. The phylogenetic trees revealed that strain BD-1(T) clustered within the genus Ottowia. Summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c, 48.2%), C-16:0 (23.2 %) and summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c, 8.6%) were the major fatty acids (>5 %), and ubiquinone-8 was the respiratory quinone. Phosphatidylethanolamine, phosphatidylmethylethanolamine and phosphatidylglycerol were identified as the major polar lipids. Meanwhile, the G+C content of the DNA was 63.6 mol% based on the draft genome analysis. The average nucleotide identity and digital DNA-DNA hybridization values between strain BD-1(T) and DSM 14619(T) were 74.5 and 21.4 %, respectively. In addition, the novel strain completely degraded 500 mg l(-1) phenylacetic acid within 72 h under the condition of 3% NaCl. Given the results of genomic, phylogenetic, phenotypic and chemotaxonomic analyses, strain BD-1(T) was considered to represent a novel species of the genus Ottowia, for which the name Ottowia caeni sp. nov. is proposed. The strain is a potential resource for the bioremediation of phenylacetic acid contaminated water. The type strain is BD-1(T) (=CGMCC 1.18541(T)=KCTC 82183(T)).