Streptomyces endocoffeicus sp. nov., an endophytic actinomycete isolated from Coffea arabica (L.)

Abstract

An aerobic, non-motile, Gram-stain positive actinomycete, designated strain CA3R110^T, was isolated from the surface-sterilised root of Coffea arabica L. collected from Lampang Province, Thailand. 16S rRNA gene sequence analysis indicated that strain CA3R110^T was a member of the genus Streptomyces and showed the closest similarities to Streptomyces buecherae AC541^T (99.2%), followed by Streptomyces rapamycinicus NRRL B-5491^T (99.1%), Streptomyces luteoverticillatus NBRC 3840^T (99.1%), Streptomyces coerulescens NBRC 12758^T (99.1%), and Streptomyces iranensis HM 35^T (99.0%). Strain CA3R110^T contained LL-diaminopimelic acid in cell peptidoglycan, MK-9(H₆), and MK-9(H₈) as major menaquinone, iso-C_16:0, iso-C_15:0, C_16:0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside were detected in the cell. The chemotaxonomic characteristics possessed the typical properties of the genus Streptomyces. A low digital DNA-DNA hybridization (< 55.7%) and average nucleotide identity-blast (ANIb) (< 92.2%) values revealed that strain CA3R110^T could be distinguished from any known Streptomyces species. With the differences in phenotypic and genotypic data, strain CA3R110^T represents a novel species of genus Streptomyces, for which the name Streptomyces endocoffeicus sp. nov. is proposed. The type strain is CA3R110^T (= TBRC 11245^T = NBRC 114296^T).

Keywords: 16S rRNA gene; Coffea arabica L; Endophytic actinobacterium; Streptomyces.