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

Strain ZZ-1(T), a Gram-negative, rod-shaped bacterium, motile by flagella, was isolated from phenol-contaminated soil. Strain ZZ-1(T) 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-1(T) is a member of the genus Nitratireductor, and shows high sequence similarities to Nitratireductor pacificus MCCC 1A01024(T) (98.5%) and lower (<97%) sequence similarities to all other Nitratireductor species. Chemotaxonomic analysis revealed that strain ZZ-1(T) possesses Q-10 as the predominant ubiquinone and Summed feature 8(C(18:1) ω6c and/or C(18:1) ω7c; 66.6%), C(19:0) ω8c cyclo (23.3%), C(18:0) (3.4%), iso-C(17:0) (2.3%) and C(17:0) (1.0%) as the major fatty acids. The polar lipids of strain ZZ-1(T) 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-1(T) and N. pacificus MCCC 1A01024(T) 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-1(T) represents a novel species of the genus Nitratireductor, for which the name Nitratireductor soli sp. nov. is proposed. The type strain is ZZ-1(T) (=JCM 30640(T) = MCCC 1K00508(T)).