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 Avilés 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 °C (optimum 28 °C) and at salinities of 0.5–10.5 % (w/v) NaCl (optimum 0.5–3.0 %). The peptidoglycan contained the amino acids Lys, Ala, Thr, Glu and one unknown amino acid component, and belonged to type A4α, 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 mol%. 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.