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

Abstract

The taxonomic position of a novel bacterial strain, designated C3T, isolated from hydrocarbon-contaminated desert sands was determined. Strain C3T was a Gram-stain-negative, rod- to curved-rod-shaped and non-motile bacterium. It was able to grow at 4-45 °C (optima, 28- 35 °C) and at pH 6.1-8.8 (optima, 6.9-7.7). No added NaCl was required for growth of strain C3T and it tolerated up to 3.5 % (w/v) NaCl with optimal growth with 0.5-1.5 %. Catalase and oxidase were positive. C18 : 1ω6c/C18 : 1ω7c, C16 : 0, C12 : 0 aldehyde, C14 : 0 3-OH/iso-C16 : 0 I and C18 : 1ω7c 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 C3T represents a member of the genus Shinella within the family Rhizobiaceae of the class Alphaproteobacteria. Strain C3Tshowed a 16S rRNA gene sequence similarity of 98.39 % with Shinella kummerowiae CCBAU 25048T, 98.37 % with Shinella granuli Ch06T, 98.17 % with Shinella zoogloeoides I-16-MT, 97.74 % with Shinella fusca DC-196T, 97.46 % with Shinella yambaruensis MS4T and <96.68 % with other members of the family Rhizobiaceae. DNA-DNA hybridization values between strain C3T 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 C3T 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 C3T (=KEMB 2255-446T=JCM 31239T).