Characterization of Pseudoalteromonas distincta-like sea-water isolates and description of Pseudoalteromonas aliena sp. nov

1 Industrial Research Institute Swinburne, Swinburne University of Technology, PO Box 218, Hawthorn, Victoria 3122, Australia 2 Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, 690022 Vladivostok, Prospekt 100 Let Vladivostoku 159, Russia 3 Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia 4 Institute of Microbiology of the Russian Academy of Sciences, 117811 Moscow, Russia 5 UMR6543 CNRS–Université de Nice Sophia Antipolis, Centre de Biochimie, Parc Valrose, F06108 Nice cedex 2, France Correspondence Elena P. Ivanova eivanova{at}swin.edu.au Seven melanogenic Pseudoalteromonas distincta -like strains, KMM 3562 T , KMM 3536, KMM 3537, KMM 3538, KMM 3539, KMM 3615 and KMM 3629, which expressed tyrosinases were isolated from sea-water samples collected from different locations in Amursky Bay (Sea of Japan, Pacific Ocean) and characterized to clarify their taxonomic position. By 16S rRNA gene sequence analysis, the bacteria were shown to belong to the genus Pseudoalteromonas . The G+C content of the DNAs of the strains was 41–43 mol%. The level of DNA similarity among these strains was conspecific (92–97 %), indicating that they represented a single genospecies. However, DNA from the strains isolated from sea water showed only 63–65 % genetic relatedness with the DNA of the type strain P. distincta . The novel organisms grew mainly between 4 and 30 °C, were neutrophilic and slightly halophilic (four strains had a narrow range of growth between 3 and 6 % NaCl, w/v), were haemolytic and cytotoxic and were able to degrade starch, gelatin and Tween 80. The predominant fatty acids, including 16 : 0, 16 : 1 7, 17 : 1 7 and 18 : 1 7, were typical of the genus Pseudolateromonas . The phylogenetic, genetic and physiological properties of the seven strains placed them within a novel species, Pseudoalteromonas aliena sp. nov., the type strain of which is SW19 T (=KMM 3562 T =LMG 22059 T ). The GenBank accession number for the 16S rRNA gene sequence of Pseudoalteromonas aliena KMM 3562 T is AY387858 . A phylogenetic tree, a comparison of fatty acid compositions and details of the phenotypic features that distinguish P. aliena sp. nov. from most other phylogenetically related species of the genus are available as supplementary material in IJSEM Online.