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 (5BCC 53154T5NBRC 110047T). An emended description of the
genus Streptosporangium is also proposed.