sp. nov., a mangrove soil actinobacterium.

A novel strain (SSL-25) was isolated from mangrove soil sampled at QinzhouBay, PR China. The isolate was observed to be Gram-stain-positive and to form greyish-white aerial mycelia that differentiated into straight spore chains with smooth-surfaced spores on International Project 2 medium. The cell-wall peptidoglycan was determined to contain ll-diaminopimelicacid. The cell-wall sugars were glucose and mannose. The predominant menaquinones were MK-9 (H6), MK-9 (H8) and MK-9 (H4). The major polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and several unidentified phospholipids. The predominant cellular fatty acids were C, iso-C and summed feature 3 (Cω7/Cω6). The genome size of strain SSL-25 was 8.1 Mbp with a G+C content of 71.5 mol%. Phylogenetic analysis indicated that strain SSL-25 is closely related to NRRL 18488 (99.4 % sequence similarity). However, the digital DNA-DNA hybridization (39.8 %) and average nucleotide identity (91.3 %) values between them showed that it represents a distinct species. Furthermore, the results of morphological, physiological and biochemical tests allowed further phenotypic differentiation of strain SSL-25 from NRRL 18488. Therefore, based on these results, it is concluded that strain SSL-25 represents a novel species, for which the name sp. nov. is proposed. The type strain is SSL-25 (=CICC 11054=JCM33585).