Phenotypic and genotypic characterization of Marinobacterium weihaiense sp. nov. and Marinobacterium marinum sp. nov., isolated from marine sediment, and genomic properties of the genus Marinobacterium

In this study, two novel bacterial strains were isolated from coastal sediment of Weihai, China. The two strains were Gramstain- negative and facultatively aerobic, designated 3- 1745T and A346T. Based on phenotypic, genetic and phylogenetic properties, strains 3- 1745T and A346T represent two novel species of the genus Marinobacterium. The results of genome analysis revealed many central carbohydrate metabolism pathways such as gluconeogenesis, pyruvate oxidation, tricyclic acid cycle, pentose phosphate pathway and PRPP biosynthesis in the genus Marinobacterium. The ability of strains 3- 1745T and A346T to utilize volatile fatty acids was experimentally confirmed. Polyhydroxyalkanoate synthases (PhaA, PhaB and PhaC) for the synthesis of polyhydroxyalkanoates were prevalent in the genus Marinobacterium. Multiple BGCs (biosynthetic gene clusters) including betalactone, ectoine, ranthipeptide, redox- cofactor, RiPPs (ribosomally synthesized posttranslationally modified peptides) and T3PKS (polyketide synthases) in the genome of the genus Marinobacterium were found. Additional genome analyses suggested that the genus Marinobacterium contained diverse potential mechanisms of salt tolerance and mainly utilized oligosaccharides. This is the first report on broad genomic analyses of the genus Marinobacterium with the description of two novel species and potential ecological and biotechnological implications.