Amycolatopsis mongoliensis sp. nov., a novel actinobacterium with antifungal activity isolated from a coal mining site in Mongolia

A novel filamentous actinobacterium designated strain 4-36 T showing broad-spectrum antifungal activity was isolated from a coal mining site in Mongolia, and its taxonomic position was determined using polyphasic approach. Optimum growth occurred at 30 °C, pH 7.5 and in the absence of NaCl. Aerial and substrate mycelia were abundantly formed on agar media. The colour of aerial mycelium was white and diffusible pigments were not formed. Phylogenetic analyses based on 16S rRNA gene sequence showed that strain 4-36 T formed a distinct clade within the genus Amycolatopsis . The 16S rRNA gene sequence similarity showed that the strain was mostly related to Amycolatopsis lexingtonensis DSM 44544 T and Amycolatopsis rifamycinica DSM 46095 T with 99.3 % sequence similarity. However, the highest digital DNA–DNA hybridization value to closest species was 44.1 %, and the highest average nucleotide identity value was 90.2 %, both of which were well below the species delineation thresholds. Chemotaxonomic properties were typical of the genus Amycolatopsis , as the major fatty acids were C 15 : 0 , iso-C 16 : 0 and C 16 : 0 , the cell-wall diamino acid was meso- diaminopimelic acid, the quinone was MK-9(H 4 ), and the main polar lipids were diphosphatidylglycerol, phosphatidylmethanolamine and phosphatidylethanolamine. The in silico prediction of chemotaxonomic markers was also carried out by phylogenetic analysis. The genome mining for biosynthetic gene clusters of secondary metabolites in strain 4-36 T revealed the presence of 34 gene clusters involved in the production of polyketide synthase, nonribosomal peptide synthetase, ribosomally synthesized and post-translationally modified peptide, lanthipeptide, terpenes, siderophore and many other unknown clusters. Strain 4-36 T showed broad antifungal activity against several filamentous fungi. The phenotypic, biochemical and chemotaxonomic properties indicated that the strain could be clearly distinguished from other species of Amycolatopsis , and thus the name Amycolatopsis mongoliensis sp. nov. is proposed accordingly (type strain, 4-36 T =KCTC 39526 T =JCM 30565 T ).