Description of Alcanivorax venustensis sp nov and reclassification of Fundibacter jadensis DSM 12178T (Bruns and Berthe-Corti 1999) as Alcanivorax jadensis comb. nov., members of the emended genus Alcanivorax

Two strains of a novel bacterium were isolated independently of each other, from different depths in the Mediterranean Sea, within a time period of 7 months, using two different isolation approaches that were focused on different objectives. Both strains, designated ISO1 and ISO4, were halophilic, Gram-negative, strictly aerobic, straight rods that were oxidase- and catalase-positive. Both strains produced mucoid colonies in some defined minimal media and were able to grow with organic acids and some alkanes; they were also able to accumulate intracellular poly-beta-hydroxybutyrate granules. The G + C content of the DNA of strain ISO4(T) was 66 mol%. Comparative analysis of 16S rRNA gene sequences showed that the closest described species to the novel strains were Alcanivorax borkumensis and Fundibacter jadensis, both of the gamma-Proteobacteria. Both of these recognized species were originally isolated from North Sea waters T and are able to degrade aliphatic compounds, a property shared with strains ISO1 and ISO4 However, strains ISO1 and ISO4(T) were different from A. borkumensis and F jadensis, not only in their 16S rDNA sequences but also in the motility of their cells (by polar flagella) and by the presence of C-19:0cyclo in their cellular fatty acids, among other differential features. On the basis of biochemical and molecular data, it is suggested that strains ISO1 and ISO4(T) be recognized as a novel species of the genus Alcanivorax, for which the name Alcanivorax venustensis (ISO4(T) =DSM 13974(T) =CECT 5388(T)) is proposed. On the basis of its high phenotypic similarity and close phylogenetic relatedness to A. borkumensis, it is also proposed that F jadensis (DSM 12178(T)) be reclassified as Alcanivorax jadensis in the genus Alcanivorax, and that the description of the genus Alcanivorax be emended.