Photobacterium halophilum sp. nov. and a Salt-Loving Bacterium Isolated from Marine Sediment

Abstract

A Gram-stain-negative, rod-shaped, and facultatively anaerobic bacterium named strain GJ3T was isolated from coastal sediment of Jeju Island, South Korea. Catalase and oxidase activity were detected in the cell of strain GJ3T, as well as white pigmented colony and motility with polar flagellum. The cell grew optimally at 30 °C, pH 7.0, in the presence of 4% (w/v) sodium chloride. Phylogenetic analysis using the 16S rRNA gene sequence indicated that strain GJ3T was classified to the genus Photobacterium, with high sequence similarity to Photobacterium galatheae S2753T (98.30%), Photobacterium halotolerans MACL01T (97.90%), and Photobacterium panuliri LBS5T (96.55%). Strain GJ3T possessed only ubiquinone-8 (Q-8) as a respiratory quinone and summed feature 8 as the major fatty acid (38.18%). Additionally, the dominant polar lipids phosphatidylglycerol and phosphatidylethanolamine were identified. The complete genome size and G + C content of strain GJ3T was estimated to be 3,603,274 bp in length and 50.70%, respectively. Polyphasic approach and genomic analyses (e.g., ANI and digital DDH) revealed that strain GJ3T (=KCTC 72816T = KMM 6822T) represented a novel species within the genus Photobacterium, and the name Photobacterium halophilum sp. nov., is proposed for this novel bacterium.