Photobacterium rosenbergii sp. nov. and Enterovibrio coralii sp. nov., vibrios associated with coral bleaching.

ABSTRACT

Six new Vibrio-like isolates originating from different species of bleached and healthy corals around Magnetic Island (Australia) were investigated using a polyphasic approach. Phylogenetic analyses based on 16S rRNA, recA and rpoA gene sequences split the isolates in two new groups. Strains LMG 22223(T), LMG 22224, LMG 22225, LMG 22226 and LMG 22227 were phylogenetic neighbours of Photobacterium leiognathi LMG 4228(T) (95.6 % 16S rRNA gene sequence similarity), whereas strain LMG 22228(T) was related to Enterovibrio norvegicus LMG 19839(T) (95.5 % 16S rRNA gene sequence similarity). The two new groups can be distinguished from closely related species on the basis of several phenotypic features, including fermentation of d-mannitol, melibiose and sucrose, and utilization of different compounds as carbon sources, arginine dihydrolase activity, nitrate reduction, resistance to the vibriostatic agent O/129 and the presence of fatty acids 15 0 iso and 17 0 iso. The names Photobacterium rosenbergii sp. nov. (type strain LMG 22223(T)=CBMAI 622(T)=CC1(T)) and Enterovibrio coralii sp. nov. (type strain LMG 22228(T)=CBMAI 623(T)=CC17(T)) are proposed to accommodate these new isolates. The G+C contents of the DNA of the two type strains are respectively 47.6 and 48.2 mol%.