Streptosporangium jomthongense sp. nov., an actinomycete isolated from rhizospheric soil and emendation of the genus Streptosporangium

Abstract

A novel actinomycete, strain 30EHST, was isolated from the rhizospheric soil under an elephant ear plant (Caladium bicolor) in Jomthong district, Bangkok, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 30EHST fell within the cluster of the genus Streptosporangium. Chemical composition analysis confirmed that the strain represented a member of the genus Streptosporangium even though this strain produced a tightly packed single spore on aerial hyphae. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain 30EHST was most closely related to Streptosporangium fragile NBRC 14311T (98.1 %), Streptosporangium carneum NBRC 15562T (97.8 %) and Streptosporangium violaceochromogenes NBRC 15560T (97.4 %). The DNA-DNA hybridization relatedness values between strain 30EHST and the above three strains were below 70 %. Based on combined data for phylogenetic analysis, DNA-DNA hybridization relatedness and physiological characteristics, it was concluded that strain 30EHST should be classified as representing a novel species of the genus Streptosporangium. We propose the name Streptosporangium jomthongense sp. nov., with the type strain 30EHST (= BCC 53154T = NBRC 110047T). An emended description of the genus Streptosporangium is also proposed. © 2014 IUMS.