Shinella curvata sp nov., isolated from hydrocarbon-contaminated desert sands

The taxonomic position of a novel bacterial strain, designated C3(T), isolated from hydrocarbon-contaminated desert sands was determined. Strain C3(T) was a Gram-stain-negative, rod-to curved-rod-shaped and non-motile bacterium. It was able to grow at 4-45 degrees C (optima, 28-35 degrees C) and at pH 6.1-8.8 (optima, 6.9-7.7). No added NaCl was required for growth of strain C3(T) and it tolerated up to 3.5% (w/v) NaCl with optimal growth with 0.5-1.5 %. Catalase and oxidase were positive. C-18:1 omega 6c/C-18:1 omega 7c, C-16:0, C-12:0 aldehyde, C-14:0 3-OH/iso-C-16:0 I and C-18:1 omega 7c 11-methyl were predominant fatty acids. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine were major polar lipids. The genomic DNA G+C content was 65.4 mol%. 16S rRNA gene sequence comparisons indicated that strain C3(T) represents a member of the genus Shinella within the family Rhizobiaceae of the class Alphaproteobacteria. Strain C3(T) showed a 16S rRNA gene sequence similarity of 98.39% with Shinella kummerowiae CCBAU 25048(T), 98.37% with Shinella granuli Ch06(T), 98.17% with Shinella zoogloeoides I-16-M-T, 97.74% with Shinella fusca DC-196(T), 97.46% with Shinella yambaruensis MS4(T) and < 96.68% with other members of the family Rhizobiaceae. DNA-DNA hybridization values between strain C3(T) and the type strains of the nearest species were clearly below the 70% threshold for species delineation. Distinct morphological, physiological and genotypic differences from previously described taxa support the classification of strain C3(T) as a representative of a novel species in the genus Shinella, for which the name Shinella curvata sp. nov. is proposed. The type strain is C3(T) (= KEMB 2255-446(T) = JCM 31239(T)).