Spinactinospora alkalitolerans gen. nov., sp nov., an actinonnycete isolated from marine sediment

A novel marine actinomycete, designated CXB654(T), was isolated from marine sediment collected at a depth of 17.5 m near the Yellow Sea Cold Water Mass, China. Optimal growth occurred at 37.0 degrees C, at pH 7.0-8.0 and in 3-8% (w/v) NaCl. Strain CXB654(T) formed branched substrate mycelium without fragmentation. Abundant aerial mycelium differentiated into long or short chains of spores and spores were elliptical and cylindrical with spiny surfaces. Strain CXB654(T) contained meso-diaminopimelic acid as the diagnostic diamino acid, and ribose and glucose as the major whole-cell components. Phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol and phosphatidylinositol. MK-10(H-8), MK-10(H-6) and MK-9(H-8) were the predominant menaquinones. The major fatty acids were i-C-16:0 (24.46%), ai-C-17:0 (20.66%) and C-18:0 (20.14%). The DNA G+C content was 71.1 mol%. Comparative analysis of 16S rRNA gene sequences showed that the novel strain was most closely related to genera within the family Nocardiopsaceae, but formed a separate lineage. Highest sequence similarities were to Murinocardiopsis flavida DSM 45312(T) (96.6%), Thermobifida halotolerans YIM 90462(T) (96.5 %) and Marinactinospora thermotolerans DSM 45154(T) (96.1%). On the basis of phenotypic, chemotaxonomic and phylogenetic distinctiveness, strain CX13654(T) was considered to represent a novel species in a new genus in the family Nocardiopsaceae, and the name Spinactinospora alkalitolerans gen. nov., sp. nov. is proposed; the type strain is CXB654(T) (=DSM 45414(T) LMG 25485(T)).