New species in Aspergillus section Fumigati from reclamation sites in Wyoming (USA) and revision of A-viridinutans complex

The Aspergillus viridinutans complex includes morphologically similar, soil-inhabiting species. Although its species boundaries have not been fully defined, many isolates from the complex have been isolated as opportunistic human and animal pathogens. In the present study, these species were dominant in spoil sites subjected to various types of reclamation management after coal mining. These species were characterised using two different PCR-fingerprinting methods, sequence data from the beta-tubulin (benA) and calmodulin (caM) genes, macro- and micromorphology (optical and scanning electron microscopy), maximum growth temperatures and mating experiments. In addition, RNA polymerase II gene (RPB2), actin (act1) and ITS sequences were deposited for the ex-type isolates of newly described species. The mating experiment results, phylogenetic analyses and ascospore morphology suggested the presence of five species in the A. viridinutans complex. Aspergillus aureolus (syn. Neosartorya aureola) was the only homothallic species. Three species, A. felis, A. udagawae (syn. N. udagawae) and A. wyomingensis sp. nov., were heterothallic and their morphologically distinguishable teleomorph was induced by systematic mating experiments. Aspergillus viridinutans s. str. seems to be a very rare species and was represented only by the ex-type isolate in which the MAT1-1 locus was amplified. Aspegillus viridinutans and A. aureolus were typified in accordance with the rules of the new botanical code. Other species outside the A. viridinutans complex isolated from the reclamation sites were A. fumigatiaffinis and A. lentulus as well as two new sister species, A. brevistipitatus sp. nov. and A. conversis sp. nov. which were closely related each to other and to N. papuensis. Both new species are phylogenetically distant from all anamorphic species and resemble A. brevipes, A. duricaulis and A. unilateralis in micromorphology and are distinguishable from each other by the slower growth of A. conversis on all tested media. Interestingly, no isolate from the reclamation sites represented A. fumigatus s. str. which is usually reported as the dominant species from the section Fumigati in soil.