Alcanivorax profundimaris sp. nov., a Novel Marine Hydrocarbonoclastic Bacterium Isolated from Seawater and Deep-Sea Sediment

Two novel Alcanivorax-related strains, designated ST75FaO-1(T) and 521-1, were isolated from the seawater of the South China Sea and the deep-sea sediment of the West Pacific Ocean, respectively. Both strains are Gram-stain-negative, rod-shaped, and non-motile, and grow at 10-40 degrees C, pH 5.0-10.0, in the presence of 1.0-15.0% (w/v) NaCl. Their 16S rRNA gene sequences showed 99.9% similarity. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that both strains belong to the genus Alcanivorax, and share 92.9-98.1% sequence similarity with all valid type strains of this genus, with the highest similarity being to type strain Alcanivorax venustensis DSM 13974(T) (98.0-98.1%). Digital DNA-DNA hybridization (dDDH) and average nucleotide identity values between strains ST75FaO-1(T) and 521-1 were 75.7% and 97.1%, respectively, while the corresponding values with A. venustensis DSM 13974(T) were only 25.4-25.6% and 82.4-82.7%, respectively. The two strains contained similar major cellular fatty acids including C-16:0, C-18:1 omega 7c/omega 6c, C-19:0 cyclo omega 8c, C-16:1 omega 7c/omega 6c, C-12:0 3-OH, and C-12:0. The genomic G + C content of strains ST75FaO-1(T) and 521-1 were 66.3% and 66.1%, respectively. Phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids, and one unidentified polar lipid were present in both strains. On the basis of phenotypic and genotypic characteristics, the two strains represent a novel species within the genus Alcanivorax, for which the name Alcanivorax profundimaris sp. nov. is proposed. The type strain is ST75FaO-1(T) (= MCCC 1A17714(T) = KCTC 82142(T)).

Automated summary

Two novel strains related to Alcanivorax, isolated from different marine environments, have been identified as a new species Alcanivorax profundimaris based on highly similar gene sequences. They share similar physiological characteristics and major cellular fatty acids, suggesting a close relationship within the genus.