Pseudoalteromonas maricaloris sp. nov., isolated from an Australian sponge, and reclassification of [Pseudoalteromonas aurantia] NCIMB 2033 as Pseudoalteromonas flavipulchra sp. nov.

A marine, gram-negative, aerobic bacterium that produced cytotoxic, lemon-yellow, chromopeptide pigments that inhibited the development of sea urchin eggs has been isolated from the Australian sponge Fascaplysinopsis reticulata Hentschel. The cells of the organism were rod-shaped with a single polar flagellum and they required NaCl for growth (0.5-10%) with optimum growth at 1-3% NaCl. The temperature for growth was 10-37 degrees C, with optimum growth at 25-30 degrees C. Growth occurred at pH values from 6.0 to 10.0, with optimum growth at pH 6.0-8.0. Major phospholipids were phosphatidylethanolamine, phosphatidylglycerol and lyso-phosphatidylethanolamine. Of 26 fatty acids with 11-19 carbon atoms that were detected, 16:1omega7, 16:0, 17:1omega8 and 18:1omega7 were predominant. The DNA G+C content was 38.9 mol%. All of these phenotypic and chemotaxonomic characters place the organism in the genus Pseudoalteromonas (Gauthier et al, 1995). These data are consistent with the phylogenetic analyses that confirmed that strain KMM 636T is a member of the Pseudoalteromonas cluster in the gamma-subclass of the Proteobacteria. DNA-DNA hybridization experiments revealed that the levels of relatedness between the DNA of the strain studied and DNAs of type strains of the species that clustered together (on the basis of 16S rDNA sequences) and [Pseudoalteromonas aurantia] NCIMB 2033 ranged from 19 to 35%, and that the DNA-DNA homology between [P. aurantia] NCIMB 2033 and other phylogenetically and/or phenotypically similar type strains ranged from 32 to 52%. According to the polyphasic evidence presented in this study, it is proposed that strain KMM 636T (= LMG 19692T = CIP 106859T) be classified as Pseudoalteromonas maricaloris sp. nov. and [P. aurantia] NCIMB 2033 be reclassified as Pseudoalteromonas flavipulchra NCIMB 2033T (= KMM 3630T = LMG 20361T) sp. nov.