Evaluation of the genus Listonella and reassignment of Listonella damsela (Love et al.) MacDonell and Colwell to the genus Photobacterium as Photobacterium damsela comb. nov. with an emended description.

The genus Listonella, which was recently described on the basis of 5S rRNA sequence data, was found to be of dubious value on the basis of the results of a comparison of a number of taxonomic studies involving members of the Vibrionaceae. The available data suggest that 5S rRNA sequences may be of limited taxonomic use at the intra- and intergeneric levels, at least for apparently recently evolved groups, such as the Vibrionaceae. In this light, we assessed the generic assignment of the species Listonella damsela. Phenotypic characterization of 12 strains of bacteria assigned to L. damsela, including type strain ATCC 33539, revealed a strong resemblance to members of the genus Photobacterium. All of the strains conformed to major characteristics common to all known Photobacterium species. The characteristics of these organisms included the absence of a flagellar sheath and accumulation of poly-beta-hydroxybutyrate during growth on glucose coupled with the inability to utilize DL-beta-hydroxybutyrate as a sole carbon source. On the basis of the phenotypic data, we propose that L. damsela should be reassigned to the genus Photobacterium as Photobacterium damsela comb. nov.