Isolation and Genomic analysis of A Novel thermophilic marine bacterium in Family level, Roseothermus cellulosivorans gen. nov., sp. nov.

Abstract

A novel bacterium, strain MEBiC09517T, was isolated from Buksung-Po, a small port in Republic of Korea. The strain MEBiC09517T has low 16S rRNA gene sequence similarity with Rubrivirga profundi SAORIC-476T, which has highest sequence similarity (89.9%) among other cultivated strains. Optimum growth condition of strain MEBiC09517T is 50-55℃, pH 7, and 2-2.5% salt concentration. Based on phylogenetic analysis and results of a physiological test, we propose the strain MEBiC09517T (=KCCM43267T=JCM32374T) for type strain of Roseothermus cellulosivorans gen. nov., sp. nov., which is a member of Roseothermaceae fam. nov. Also, genome sequencing that was conducted by using the PacBio RS II system results in a circularized genome with 4.81 Mbps size and 3,808 CDSs. The G + C content in DNA is 68.65 mol% and the genome exhibits genes encoding thermostable cellulose and many additional glycoside hydrolases affiliated with variety of GH families. While the strain MEBiC09517T is evolutionarily very close to the genome of strain RA, it shows larger genome size than strain RA. The reason why this thermophilic and moderately halophilic bacterium was found in the small port of the Korean coast is that this region is exposed to sunlight during an ebb tide, which is expected to be an endurable growth condition for MEBiC09517T, which can survive in higher temperature and more salt than ordinary seawater. Additionally, novel family Salirity (89.9%) among other cultivated strains. Optimum growth condition of strain MEBiC09517T is 50-55℃, pH 7, and 2-2.5% salt concentration. Based on phylogenetic analysis and results of a physiological test, we propose the strain MEBiC09517T (=KCCM43267T=JCM32374T) for type strain of Roseothermus cellulosivorans gen. nov., sp. nov., which is a member of Roseothermaceae fam. nov. Also, genome sequencing that was conducted by using the PacBio RS II system results in a circularized genome with 4.81 Mbps size and 3,808 CDSs. The G + C content in DNA is 68.65 mol% and the genome exhibits genes encoding thermostable cellulose and many additional glycoside hydrolases affiliated with variety of GH families. While the strain MEBiC09517T is evolutionarily very close to the genome of strain RA, it shows larger genome size than strain RA. The reason why this thermophilic and moderately halophilic bacterium was found in the small port of the Korean coast is that this region is exposed to sunlight during an ebb tide, which is expected to be an endurable growth condition for MEBiC09517T, which can survive in higher temperature and more salt than ordinary seawater. Additionally, novel family Sali