Abstract

A diesel-oil and n-hexadecane-degrading novel bacterial strain, designated DR1T, was isolated from a rice paddy in Deok-So, South Korea. The strain DR1T cells were Gram-negative, aerobic coccobacilli, and grew at 20-37°C with the optimal temperature of 30°C, and an optimal pH of 6-8. Interestingly, strain DR1T was highly motile (swimming and swarming motility) using its fimbriae, and generated N-acyl homoserine lactones as quorum-sensing signals. The predominant respiratory quinone as identified as ubiquinone-9 (Q-9) and DNA G+C content was 41.4 mol%. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a clade with the species A. calcoaceticus, A. haemolyticus, A. baumannii, A. baylyi, and A. beijerinckii, with which it evidenced sequence similarities of 98.2%, 97.4%, 97.2%, 97.1%, and 97.0%, respectively. DNA-DNA hybridization values between strain DR1T and other Acinetobacter spp. were all less than 20%. The physiological and taxonomic characteristics with the DNA-DNA hybridization data supported the identification of strain DR1T in the genus Acinetobacter as a novel species, for which the name Acinetobacter oleivorans sp. nov. is proposed. The type strain is DR1T (=KCTC 23045T =JCM 16667T).

• Keywords: bacteria; biodegradation; genome; diesel; soil; biofilm