Nitratireductor shengliensis sp. nov., isolated from an oil-polluted saline soil

Two Gram-negative, non-motile, short-rod-shaped bacterial isolates, designated 110399(T) and 110248, were isolated from an oil-polluted saline soil in Shengli Oilfield, Eastern China. The two strains shared 99.9 % 16S rRNA gene sequence similarity with the DNA-DNA relatedness value being 80.0 %. They were both capable to grow at 20-40 °C, pH 7-9, and 1-9 % (w/v) NaCl with the optimum growth happened at 30 °C, pH 8, and 2-6 % (w/v) NaCl. The phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains were members of Nitratireductor and most closely related to Nitratireductor pacificus pht-3B(T) and N. basaltis J3(T) with the 16S rRNA gene sequence similarities being 97.1 and 97.0 %. The DNA-DNA relatedness between the novel strains and two type strains were below 27 ± 7 %. The strains 110399(T) and 110248 also differed from N. pacificus and N. basaltis in nitrate reduction, salt tolerance, enzyme activities, and utilization of carbon sources. The major cellular fatty acids of strain 110399(T) were C19:0ω8c cyclo (10.5 %) and Summed Feature 8 (C18:1ω7c and/or C18:1ω6c, 41.5 %) which are typical in the genus Nitratireductor. The predominant ubiquinone was Q-10. The genome DNA G+C content of strain 110399(T) and 110248 was 61.1 and 61.7 mol%. On the basis of genetic, phenotypic, and chemotaxonomic analyses, strains 110399(T) and 110248 represent a novel species within the genus Nitratireductor, for which the name Nitratireductor shengliensis sp. nov. is proposed. The type strain is 110399(T) (=CGMCC 1.12519(T) = LMG 27405(T)).