gen. nov., sp. nov., isolated from marine sediment of Valparaíso Bay (Chile) and proposal for reclassification of two species of the genus .

An alkaliphilic actinobacterium, designated VN6-2, was isolated from marine sediment collected from Valparaíso Bay, Chile. Strain VN6-2 formed yellowish-white branched substrate mycelium without fragmentation. Aerial mycelium was well developed, forming wavy or spiral spore chains. Strain VN6-2 exhibited a 16S rRNA gene sequence similarity of 93.9 % to CXB832, 93.7 % to 14-Be-013, and 93.7 % to 14-Be-013. Genome sequencing revealed a genome size of 5.9 Mb and an G+C content of 69.3 mol%. Both of the phylogenetic analyses based on 16S rRNA gene sequences and the up-to-date bacterial core gene sequences revealed that strain VN6-2 formed a distinct monophyletic clade within the family . Chemotaxonomic assessment of strain VN6-2 showed that the major fatty acids were iso-C, anteiso-C and 10-methyl-C, and the predominant respiratory quinones were MK-9, MK-9(H) and MK-9(H). Whole-cell hydrolysates contained -diaminopimelic acid as the cell-wall diamino acid, and ribose and xylose as the diagnostic sugars. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, aminophospholipids, glycolipid and phospholipid. Based on the results of this polyphasic study, a novel genus, gen. nov., is proposed within the family and the type species gen. nov., sp. nov. The type strain is VN6-2 (CECT 30026, CCUG 66258). On the basis of the phylogenetic results herein, we also propose that are later heterotypic synonyms of and , respectively, for which emended descriptions are given.