Pseudoalteromonas pernae sp. nov., a novel bacterium with antimicrobial potential isolated from the intestinal tract of mussel genus Perna (Bivalvia: Mytilidae)

The two bacterial strains, designated YIC-656 T and YIC-468, were isolated from the intestinal tract of Perna mussels (Bivalvia: Mytilidae) in China. Both strains were Gram-negative, aerobic, rod-shaped and motile, with a single polar flagellum. Strain YIC-656 T exhibited the highest 16S rRNA gene sequence similarity (98.4%) to strain Pseudoalteromonas ruthenica KMM300 T , followed by Pseudoalteromonas caenipelagi JBTF-M23 T and Pseudoalteromonas xishaensis E418 T , with sequence similarities of 98.3% and 98.2%, respectively. The 16S rRNA gene sequence similarity between strains YIC-656 T and YIC-468 was 99.9%, and their DNA G+C contents were both 45.3%. By genomic analyses, the average nucleotide identity and digital DNA–DNA hybridization values of strain YIC-656 T with any other related species were below 74.3% and 21.8%, while the indices between YIC-656 T and YIC-468 were 98.8% and 91.3%, respectively. These results indicate that strains YIC-656 T and YIC-468 belong to the same species and are distinct from other species within the genus Pseudoalteromonas . Phenotypic and chemotaxonomic tests further validated their differentiation from the closest relatives. The fatty acid profiles of both strains mainly (>7.0%) consisted of C 16:0 , summed feature 3 (comprising C 16:1 ω 7c and/or C 16:1 ω 6c ), summed feature 8 (comprising C 18:1 ω 7c and/or C 18:1 ω 6 c ) and C 18:0 . The predominant respiratory quinone was Q-8. The polar lipids included phosphatidylethanolamine and unidentified lipids. Based on these phenotypic and genotypic results, strains YIC-656 T and YIC-468 represent a new species of Pseudoalteromonas , for which we propose Pseudoalteromonas pernae sp. nov. The type strain is YIC-656 T (=MCCC 1K08806 T =KCTC 8211 T ).