Acinetobacter sp. strain Ths, a novel psychrotolerant and alkalitolerant bacterium that utilizes hydrocarbon

A novel psychrotolerant, alkalitolerant bacterium, strain Ths, was isolated from a soil sample immersed in hot spring water containing hydrocarbons and grown on a chemically defined medium containing n-tetradecane as the sole carbon source. The isolate grew at 0 degrees C but not at temperatures higher than 45 degrees C; its optimum growth temperature was 27 degrees C. It grew in the pH range of 7-9. The strain utilized C(13)-C(30) n-alkane and fluorene at pH 9 and 4 degrees C. To our knowledge, this is the first report on the bacterium that utilizes a wide range of hydrocarbons at a high pH and a low temperature. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Ths is closely related to genomic species 6 ATCC 17979 (99.1% similarity), genomic species BJ13/TU14 ATCC 17905 (97.8% similarity), genomic species 9 ATCC 9957 (97.6% similarity) belonging to the genus Acinetobacter and to Acinetobacter calcoaceticus JCM 6842(T) (97.5% similarity). DNA-DNA hybridization revealed that the isolate has 62, 25, 18 and 19% relatedness, respectively, to genomic species 6 ATCC 17979, genomic species BJ13/TU14 ATCC 17905, genomic species 9 ATCC 9957 and A. calcoaceticus, respectively.