A mesophilic strain, designated A 9500T, was isolated from a soil sample collected from Sobaek Mountain, South Korea, and its taxonomic position was investigated by using a polyphasic approach. The novel strain grew well on different ISP media and no diffusible pigments were produced. The optimum temperature for growth was 32 degrees C. The aerial mycelium was well developed, but not fragmented. The strain was Gram-positive, non-motile and formed endospores on vegetative and aerial hyphae with a spiny surface. Cell walls of strain A 9500T contained meso-diaminopimelic acid as the diagnostic amino acid, but no characteristic sugars or other amino acids were found (chemotype-III). The major menaquinone was MK-9(H4) and the minor menaquinone was MK-10(H4) and they were detected at a ratio of 7:3. Phosphatidylethanolamine was the diagnostic phospholipid. The G+C content of the genomic DNA was 39.4 mol%. The major fatty acids were anteiso-C15:0 (43.34%), iso-C16:0 (14.23%) and C16:0 (7.90%), a composition that differed from members of related genera of the family Thermoactinomycetaceae. The novel strain formed a distinct clade in a phylogenetic tree based on 16S rRNA gene sequences. On the basis of a range of phenotypic and genotypic data and on 16S rRNA gene sequence similarities (88.35-90.38%), it is suggested that strain A 9500T represents a novel species in a new genus with the name Shimazuella kribbensis gen. nov., sp. nov. The type strain of the type species is A 9500T (=KCTC 9933T=DSM 45090T).