Acinetobacter halotolerans sp. nov., a novel halotolerant, alkalitolerant, and hydrocarbon degrading bacterium, isolated from soil.

Abstract

A novel aerobic, non-motile, halotolerant, alkalitolerant, hydrocarbon degrading, and rod shaped bacterium, designated strain R160T, was isolated from soil in South Korea. Cells were Gram-staining-negative, catalase-positive, and oxidase-negative. This strain grew up to 7% of NaCl and in the pH range of 6-11 (optimum 7.0-10.0). The isolate degraded 51.7 ± 1.3% of hydrocarbon components (C-18, C-20, and C-22) and 45.8 ± 1.4% oil components (kerosene, diesel, and gasoline). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain R160T formed a lineage within the genus Acinetobacter, and was closely related to 'Acinetobacter oleivorans' DR1T (97.47%, sequence similarity). Other closely related members have sequence similarity between 97.47 to 96.52%. The predominant respiratory lipoquinones of strain R160T were ubiquinone 9 (Q-9) and ubiquinone 8 (Q-8). The major polar lipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), and phosphatidylcholine (PC). The major cellular fatty acids were 9-octadecenoic acid (C18:1 ω9c), hexadecanoic acid (C16:0), and summed feature (comprising C16:1 ω7c and/or C16:1 ω6c). The DNA G + C content of strain R160T was 44.9mol%. On the basis of phenotypic, genotypic, chemotaxonomic, and phylogenetic characteristics, strain R160T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter halotolerans sp. nov. is proposed. The type strain is R160T (= KEMB 9005-333T = KACC 18453T = JCM 31009T).