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 °C (optimum, 30 °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} ω7c and/or C_{16 : 1} ω6c, 48.2 %), C_{16 : 0} (23.2 %) and summed feature 8 (C_{18 : 1} ω7c and/or C_{18 : 1} ω6c, 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).