Alcanivorax dieselolei sp. nov., a novel alkane-degrading bacterium isolated from sea water and deep-sea sediment

Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration, People's Republic of China Correspondence Zongze Shao shaozz{at}163.com Two bacterial strains, B-5 T and NO1A, were isolated from the surface water of the Bohai Sea and deep-sea sediment of the east Pacific Ocean, respectively. Both strains were halophilic, aerobic, Gram-negative, non-spore-forming, catalase- and oxidase-positive motile rods. They grew on a restricted spectrum of organic compounds, including some organic acids and alkanes. On the basis of 16S rRNA gene sequence similarity, strains B-5 T and NO1A were shown to belong to the - Proteobacteria . Highest similarity values were found with Alcanivorax venustensis (95·2 %), Alcanivorax jadensis (94·6 %) and Alcanivorax borkumensis (94·1 %). Principal fatty acids of both strains were C 16 : 0 , C 16 : 1 7 c and C 18 : 1 7 c . The chemotaxonomically characteristic fatty acid C 19 : 0 cyclo 8 c was also detected. On the basis of the above, together with results of physiological and biochemical tests, DNA–DNA hybridization, comparisons of 16S–23S internal transcribed spacer sequences and comparisons of the partial deduced amino acid sequence of alkane hydroxylase, both strains were affiliated to the genus Alcanivorax but were differentiated from recognized Alcanivorax species. Therefore, a novel species, Alcanivorax dieselolei sp. nov., represented by strains B-5 T and NO1A is proposed, with the type strain B-5 T (=DSM 16502 T =CGMCC 1.3690 T ). Abbreviations: AlkB ( alkB ), alkane hydroxylase; ITS, internally transcribed spacer The GenBank/EMBL/DDBJ accession numbers for the nucleotide sequences reported in this study are AY683537 ( A. dieselolei B-5 T , 16S rRNA gene), AY683538 (B-5 T , large ITS), AY683539 (B-5 T , small ITS), AY683540 (B-5 T , partial alkB gene), AY683531 ( A. dieselolei NO1A, 16S rRNA gene), AY683532 (NO1A, large ITS), AY683533 (NO1A, small ITS), AY683534 (NO1A, partial alkB gene), AY683536 ( A. jadensis T9 T , partial alkB gene) and AY683535 ( A. venustensis ISO4 T , partial alkB gene). Transmission electron micrographs of cells of strains B-5 T and NO1A and dendrograms showing the phylogenetic positions of the two strains plus recognized members of the genus Alcanivorax based on 16S rRNA, ITS and alkB gene sequences are available as supplementary figures in IJSEM Online, together with a table giving DNA–DNA relatedness values.