Mangrovihabitans endophyticus gen. nov., sp. nov., a new member of the family Micromonosporaceae isolated from Bruguiera sexangula.

A novel endophytic actinobacterium, designated strain S3Cf-2T, was isolated from a surface-sterilized bark of Bruguiera sexangula collected from Dongzhaigang National Nature Reserve in Hainan Province, China. Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain S3Cf-2T fell within the family Micromonosporaceae and formed a distinct clade in the Micromonosporaceae phylogenetic tree. The 16S rRNA gene sequence similarity values between strain S3Cf-2T and the type species of 30 genera in the family Micromonosporaceae were 91.55-97.45 %. Strain S3Cf-2T formed extensively branched substrate mycelia without fragmentation. An oval or rod-like spore with a smooth surface was borne singly at the end of substrate mycelium. The novel isolate possessed meso-diaminopimelic acid as the diamino acid of the peptidoglycan, and glucose, galactose, mannose, arabinose, xylose and ribose as whole-cell sugars. The acyl type of the cell-wall peptidoglycan was glycolyl and mycolic acids were absent. The major polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and an unknown aminolipid, corresponding to phospholipid type PII. The major menaquinones were MK-9(H6) and MK-9(H8). The major cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0, anteiso-C17 : 0 and iso-C15 : 0. The G+C content of the genomic DNA was 71.4 mol%. On the basis of phylogenetic, phenotypic and chemotaxonomic analyses, strain S3Cf-2T represents a novel species of a new genus within the family Micromonosporaceae, for which the name Mangrovihabitans endophyticus gen. nov., sp. nov. is proposed. The type strain of the type species is S3Cf-2T (=DSM 100693T=CGMCC 4.7299T).