Streptomyces coffeae sp. nov., an endophytic actinomycete isolated from the root of Coffea arabica (L.)

An endophytic actinobacterium, designated strain CA1R205 T , was isolated from the surface-sterilized root of Coffea arabica L. collected from Ratchaburi province, Thailand. The taxonomic position of this strain was evaluated using a polyphasic approach. The strain produced light yellowish brown to dark brownish black substrate mycelium and greyish white aerial mycelium. The spiral spore chains were produced directly on aerial mycelium. CA1R205 T was found to have ll -diaminopimelic acid in the cell peptidoglycan, galactose, glucose, mannose and ribose as whole-cell reducing sugars, MK-10(H 4 ), MK-9(H 6 ), MK-10(H 2 ), MK-9(H 4 ), MK-10(H 6 ) and MK-10(H 8 ) as menaquinones and iso-C 15 : 0 , anteiso-C 15 : 0 , iso-C 16 : 0 and C 16 : 0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol were detected in the cells. These characteristics were consistent the typical chemotaxonomic properties of members the genus Streptomyces . The taxonomic affiliation at the genus level of this strain could be confirmed using its 16S rRNA gene sequence data. CA1R205 T showed the highest 16S rRNA gene sequence similarity value to Streptomyces rapamycinicus NRRL B-5491 T (98.9 %), followed by Streptomyces iranensis HM 35 T (98.8 %). Digital DNA–DNA hybridization and average nucleotide identity-by blast (ANIb) values between CA1R205 T and S. rapamycinicus NRRL B-5491 T were 27.2 and 81.5 %, respectively. The DNA G+C content of genomic DNA was 70.7 mol%. Due to the differences in physiological, biochemical and genotypic data, CA1R205 T could be discriminated from its closest neighbour. Thus, CA1R205 T should be recognized as representing a novel species of the genus Streptomyces , for which the name Streptomyces coffeae sp. nov. is proposed. The type strain is CA1R205 T (=TBRC 11244 T =NBRC 114295 T ).