Simiduia curdlanivorans sp. nov., a curdlandegrading bacterium isolated from the junction between the ocean and a freshwater spring, and emended description of the genus Simiduia

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped bacterial strain, designated DMCK3-4^T, was isolated from the zone where the ocean and a freshwater spring meet at Jeju island, South Korea. Strain DMCK3-4^Tgrew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0% (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain DMCK3-4^Tclustered with the strains of three members of the genus Simiduia, with which it exhibited 97.0-99.0% sequence similarity. Sequence similarities to the type strains of the other species with validly published names were less than 92.2 %. Strain DMCK3-4T contained Q-8 as the predominant ubiquinone and summed feature 3 (C_{16 : 1}ω7c and/or C_{16 : 1}ω6c), C_{17 : 1}v8c, C_{16 : 0}, C_{17 : 0}and C_{18 : 1}ω7c as the major fatty acids. The major polar lipids of strain DMCK3-4T were phosphatidylethanolamine, phosphatidylglycerol, two unidentified glycolipids, one unidentified lipid and one unidentified aminolipid. The DNA G+C content of strain DMCK3-4^Twas 51.8 mol% and its mean DNA-DNA relatedness values with Simiduia agarivorans KCTC 23176^T, Simiduia areninigrae KCTC 23293^Tand Simiduia litorea NRIC 0917^Twere 23-34 %, respectively. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain DMCK3-4^Tis distinct from other species of the genus Simiduia. On the basis of the data presented, strain DMCK3-4^Tis considered to represent a novel species of the genus Simiduia, for which the name Simiduia curdlanivorans sp. nov. is proposed. The type strain is DMCK3-4^T(=KC^TC 42075^T=CEC^T8570^T). An emended description of the genus Simiduia is also proposed.