Nitratireductor soli sp. nov., isolated from phenol-contaminated soil

Strain ZZ-1T, a Gram-negative, rod-shaped bacterium, motile by flagella, was isolated from phenol-contaminated soil. Strain ZZ-1T was found to grow at 15–37 °C (optimum 25–30 °C), at pH 6.0–10.0 (optimum pH 7.5) and with 0–8.0 % (w/v) NaCl (optimum 0.5 %). The isolate was found to be able to reduce nitrate to nitrite, but not to nitrogen. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain ZZ-1T is a member of the genus Nitratireductor, and shows high sequence similarities to Nitratireductor pacificus MCCC 1A01024T (98.5 %) and lower (<97 %) sequence similarities to all other Nitratireductor species. Chemotaxonomic analysis revealed that strain ZZ-1T possesses Q-10 as the predominant ubiquinone and Summed feature 8(C18:1ω6c and/or C18:1ω7c; 66.6 %), C19:0ω8c cyclo (23.3 %), C18:0 (3.4 %), iso-C17:0 (2.3 %) and C17:0 (1.0 %) as the major fatty acids. The polar lipids of strain ZZ-1T were determined to be diphosphatidylglycerol, phosphatidylcholine, phospholipids, aminolipids, a glycolipid and an aminophospholipid. The DNA G+C content was determined to be 64.1 mol%. Based on the draft genome sequence, the DNA–DNA hybridization estimate value between strain ZZ-1T and N. pacificus MCCC 1A01024T was 46.5 ± 3.0 % and ANI was 75.9 %. The combination of phylogenetic analysis, phenotypic characteristics, chemotaxonomic data and DNA–DNA hybridization supports the conclusion that strain ZZ-1T represents a novel species of the genus Nitratireductor, for which the name Nitratireductor soli sp. nov. is proposed. The type strain is ZZ-1T (=JCM 30640T = MCCC 1K00508T).