Streptomyces corallincola and Kineosporia corallincola sp. nov., two new coral-derived marine actinobacteria

Abstract

Two new marine actinobacteria, designated as J2-1^T and J2-2^T, were isolated from a coral, <i>Favites pentagona</i>, collected from Rayong Province, Thailand. The taxonomic positions of the two strains were identified based on polyphasic taxonomy. Based on morphological characteristics and chemotaxonomy, strains J2-1^T and J2-2^T were identified as members of the genus <i>Streptomyces</i> and <i>Kineosporia</i>, respectively. Strains J2-1^T and J2-2^T showed the highest 16S rRNA gene sequence similarity to <i>Streptomyces broussonetiae</i> T44^T (98.62 %) and <i>Kineosporia babensis</i> VN05A0415^T (98.08 %), respectively. Strain J2-1^T had chemotaxonomic properties resembling members of the genus <i>Streptomyces</i>. ll-Diaminopimelic acid, glucose and ribose were detected in the whole-cell hydrolysate. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositolmannoside, unidentified aminolipid and five unidentified phospholipids were detected as the polar lipids. The major cellular fatty acids were C_{16 : 0} iso, C_{15 : 0} anteiso, C_{15 : 0} iso, C_{16 : 0}, C_{17 : 0} anteiso, C_{14 : 0} iso and C_{17 : 0} iso. Strain J2-2^T a showed similar cell composition to members of the genus <i>Kineosporia</i>. Both isomers of ll- and <i>meso</i>-diaminopimelic acid were detected in the peptidoglycan. Arabinose, galactose, madurose and xylose were observed in the whole-cell hydrolysate. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, phosphatidylcholine, an unidentified phospholipid and an unidentified glycolipid. The major cellular fatty acids were C_{16 : 0}, C_{18 : 1} ω9<i>c</i>, C_{18 : 0} 10-methyl, tuberculostearic acid, C_{18 : 0} and C_{17 : 0}. Both strains could be distinguished from their closely related type strains according to their phenotypic characteristics. Comparative genome analysis indicated the delineation of two novel species based on digital DNA-DNA hybridization and average nucleotide identity values, which were below 70 and 95 %, respectively. The names proposed are <i>Streptomyces corallincola</i> sp. nov. (J2-1^T=TBRC 13503^T=NBRC 115066^T) and <i>Kineosporia corallincola</i> sp. nov. (J2-2^T=TBRC 13504^T=NBRC 114885^T).