Actinomycetospora aeridis sp. nov., Actinomycetospora flava sp. nov. and Actinomycetospora aurantiaca sp. nov., endophytic actinobacteria isolated from wild orchid ( Aerides multiflora Roxb)

Three novel mycelium- forming actinobacteria, designated OC33EN06T, T , OC33-EN07T, T , and OC33EN08T, T , were isolated from wild orchid ( Aerides multiflora Roxb), collected from a hill evergreen forest in Northern Thailand. Strains OC33- EN06T T and OC33EN07T T showed the highest 16S rRNA gene similarity with Actinomycetospora lutea TT00-04T, T , 99.17 and 99.45%, respectively. Strain OC33-EN08T T showed high similarity with four species, namely ' Actinomycetospora termitidis Odt1-22T' T ' (99.37%), Actinomycetospora chiangmaiensis DSM 45062T T (99.02%), Actinomycetospora corticicola 014-5T T (99.02%), and Actinomycetospora soli SF1T T (98.81%). Comparative genome analysis of OC33EN06T, T , OC33-EN07T, T , and OC33EN08Twith T with the closely related type strains showed that average nucleotide identity (ANI) based on BLAST, ANI based on MUMmer, and average amino acid identity values were less than 95% and the digital DNA-DNA hybridization values were less than 70%, all below the thresholds for species demarcation. The digital G+C content of OC33EN06T, T , OC33-EN07T, T , and OC33- EN08T T were 74.5, 74, and 74 mol%, respectively. These three strains developed bud- like chains of non- motile cylindrical spores with a smooth surface. The cell- wall peptidoglycan contained meso-- diaminopimelic acid. The whole- cell sugars contained ribose, arabinose, and galactose. The predominant menaquinone was MK- 8(H4). 4 ). The phospholipid profile included phosphatidylcholine, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylinositol. Based on comparative analysis of genotypic, phenotypic and chemotaxonomic data, strains OC33- EN06T T (=TBRC 18349T=NBRC T =NBRC 116543T), T ), OC33-EN07T T (=TBRC 18350T=NBRC T =NBRC 116544T), T ), and OC33- EN08T T (=TBRC 18318T=NBRC T =NBRC 116542T) T ) represent the type strains of three novel species of the genus Actinomycetospora for which the names Actinomycetospora aeridis sp. nov., Actinomycetospora flava sp. nov., and Actinomycetospora aurantiaca sp. nov., are proposed.