The taxonomic position of two actinomycete strains, LC2(T) and LC11(T), isolated from a filtration substrate made from Japanese volcanic soil, was determined using a polyphasic approach. The strains grew at temperatures from 5 to 45 degrees C, on media of pH between 6 and 11 and in the presence of 7 % NaCl. The major menaquinone was MK-9(H(4)). The major fatty acid was iso-C(16 : 0). A phylogenetic tree based on 16S rRNA gene sequences showed that the two strains formed a distinct evolutionary lineage within the genus Amycolatopsis. On the basis of their morphological, physiological and genotypic characteristics, the isolates are proposed to represent two novel species of the genus Amycolatopsis, for which the names Amycolatopsis echigonensis sp. nov. (type strain LC2(T) =IAM 15387(T) =CCTCC AB206019(T)), and Amycolatopsis niigatensis sp. nov. (type strain LC11(T) =IAM 15388(T) =CCTCC AB206020(T)) are proposed.