A novel actinomycete, designated strain PT708T, was isolated from cave soil collected in Pha Tup Cave Forest Park, Nan province, Thailand. It produced compounds with antimicrobial and anticancer activities. Its chemotaxonomic properties were consistent with those of members of the genus
Nonomuraea
. The major menaquinone was MK-9(H4), with minor amounts of MK-9(H6), MK-9(H2), MK-10(H2) and MK-8(H4). The polar lipid profile contained phosphatidylmonomethylethanolamine, diphosphatidylglycerol, hydroxy-phosphatidylmonomethylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. The major fatty acids were iso-C16 : 0, 10-methyl C17 : 0, C16 : 0 and C17 : 1ω6c. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PT708T belonged to the genus
Nonomuraea
and was most closely related to
Nonomuraea rhizophila
YIM 67092T (98.50 % sequence similarity) and
Nonomuraea rosea
GW 12687T (98.30 %). The genomic DNA G+C content of strain PT708T was 73.3 mol%. Unlike the recognized members of the genus
Nonomuraea
, the novel strain formed single spores at the tips of aerial hyphae. Based on the phenotypic, phylogenetic and genotypic evidence, strain PT708T represents a novel species of the genus
Nonomuraea
, for which the name Nonomuraea monospora sp. nov. is proposed. The type strain is PT708T ( = TISTR 1910T = JCM 16114T).