Myceligenerans cantabricum sp nov., a barotolerant actinobacterium isolated from a deep cold-water coral

An actinobacterium strain (M-201(T)) was isolated from a deep-sea scleractinian coral (Fam. Caryophillidae) collected at 1500 m depth in the Aviles Canyon in the Cantabrian Sea, Asturias, Spain. Strain M-201(T) grew at pH 6.0-9.0 (optimum pH 7.0), between 4 and 37 degrees C (optimum 28 degrees C) and at salinities of 0.5-10.5% (w/v) NaCl (optimum 0.5-3.00/). The peptidoglycan contained the amino acids Lys, Ala, Thr, Glu and one unknown amino acid component, and belonged to type A4 alpha, and the cell-wall sugars are glucose, mannose and galactose. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unknown phosphoglycolipid and seven unknown glycolipids. The predominant menaquinones were MK-9(H-4) and MK-9(H-6). Major cellular fatty acids were anteiso-C-15:0, iso-C-15:0 and anteiso-C-17:0. The genomic DNA G+C content was 72.4 molok. The chemotaxonomic properties supported the affiliation of strain M-201(T) to the genus Myceligenerans. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the organism was most closely related to Myceligenerans crystallogenes CD12E2-27(T) (98.2% 16S rRNA gene sequence similarity). However, it had a relatively low DNA-DNA relatedness value with the above strain (48%). The isolate showed antibiotic activity against Escherichia coli, Micrococcus luteus ATCC 14452 and Saccharomyces cerevisiae var. carlsbergensis. To the best of our knowledge, this is the first report of antibiotic production in the genus Myceligenerans. The differences in phenotypic, metabolic, ecological and phylogenetic characteristics justify the proposal of a novel species of the genus Myceligenerans, Myceligenerans cantabricum sp. nov., with M-201(T) (=CECT 8512(T)=DSM 28392(T)) as the type strain.