Corynebacterium Alimapuense Sp. Nov., An Obligate Marine Actinomycete Isolated From Sediment Of Valparaiso Bay, Chile

A novel Gram-positive, non-motile, non-spore-forming and aerobic bacterium, designated strain VA37-3(T), was isolated from a marine sediment sample collected at 19.2 m water depth from Valparaiso bay, Chile. Strain VA37-3(T) exhibits 97.6 % 16S rRNA gene sequence similarity to Corynebacterium marinum D7015(T), 96.4% to Corynebacterium humireducens MFC-5(T) and 96 % to Corynebacterium testudinoris M935/96/4(T); and a rpoB gene sequence similarity of 85.1 % to Corynebacterium pollutisoIi VMS11(T), both analyses suggesting that strain VA37-3(T) represents a novel species of Corynebacterium. Physiological testing indicated that strain VA37-3(T) requires artificial sea water or sodium-supplemented media for growth, representing the first obligate marine actinomycete of the genus Corynebacterium. The genome of the proposed new species, along with the type strains of its most closely related species were sequenced and characterized. In silico genome-based similarity analyses revealed an ANIb of 72.8 % (C. marinum D7015(T)), ANIm of 85.0 % (Corynebacterium mustelae DSM 45274(T)), TETRA of 0.90 (Corynebacterium callunae DSM 20147(T)) and GGDC of 24.7 % ( Corynebacterium kutscheri DSM 20755(T)) when compared with the closest related strains. The genomic DNA G+C content of strain VA37-3(T) was 57.0 %. Chemotaxonomic assessment of strain VN6-2(T) showed the major fatty acids were C-18:1 omega 9c and C-16.0. Menaquinones predominantly consisted of MK-8(II-H2). Polar lipids consisted of diphosphatidylglycerol, glycolipids, phosphatidylglycerol, phosphoglycolipid and phosphatidylinositol. Mycolic acids also were present. Overall, the results from phylogenetic, phenotypic and genomic analyses confirmed that strain VA37-3(T) represents a novel species of the genus Corynebacterium, for which the name Corynebacterium alimapuense sp. nov. is proposed, with VA37-3(T) as the type strain (=CCUG 69366(T)=NCIMB 15118(T)).