Streptomyces dysideae sp. nov., isolated from a marine Mediterranean sponge Dysidea tupha

A Gram-stain-positive bacterium, strain RV15(T), forming an extensively branched substrate mycelium and aerial hyphae that differentiate into spiral chains of spores, was isolated from a marine sponge Dysidea tupha collected from Rovinj (Croatia). Comparison of 16S rRNA gene sequences showed that strain RV15(T) is a member of the genus Streptomyces with highest sequence similarity to the type strains of Streptomyces caeruleatus (98.8%), Streptomyces cyaneochromogenes (98.6 %) and Streptomyces shaanxiensis (98.5 %). Sequence similarities to all other Streptomyces types strains were below 98.5 %. The multilocus sequence analysis-based evolutionary distance, the average nucleotide identity value and the genome-to-genome distance of strain RV15T and the type strain of S. caeruleatus were clearly below the species cut-off values. Strain RV15T exhibited a quinone system composed of the major menaquinones MK-9(H-4), MK-9(H-6) and MK-9(H-2), typical for the genus Streptomyces. The polar lipid profile of strain RV15(T) consisted of the predominant compounds diphosphatidylglycerol and phosphatidylethanolamine, moderate amounts of phosphatidylinositol, phosphatidylinositol mannoside, an unidentified lipid and an unidentified phospholipid. Major polyamines were spermine and spermidine. The diagnostic diaminoacid of the peptidoglycan was meso-diaminopimelic acid. The major fatty acids were iso C16.0, anteiso C17.1 omega 9c and anteiso C17.0. The results of physiological and biochemical tests allowed further phenotypic differentiation of strain RV15(T) from its most-related species and hence clearly merits species status. We propose the name Streptomyces dysideae sp. nov. with the type strain RV15T (=DSM 42110(T)=LMG 27702(T)).