Taxonomic revision of Eurotium and transfer of species to Aspergillus

Abstract

Aspergillus section Aspergillus contains economically important, xerophilic fungi that are widely distributed in nature and the human environment and are known for their ability to grow on substrates with low water activity. The taxa were revised based on sequence data from four loci, PCR fingerprinting, micro- and macromorphology, and physiology. The number of taxa was reduced to 17 species, all of which can be distinguished with sequence data from either the caM or RPB2 locus. The original description of A. proliferans was supplemented by a description of its teleomorph. This species seems to be relatively common and often has been confused with A. glaucus. In addition, green sporulating isolates of A. niveoglaucus isolated from food and several other substrates are indistinguishable in phenotype from A. glaucus. A dichotomous key based on ascospore size and ornamentation and the ability to grow at specific combinations of temperature and water activity is provided for identification of species. In response to recent changes in the botanical code, we transferred the Eurotium species to Aspergillus and selected one name for each species.

• food spoilage
• low water activity
• multilocus sequence typing
• scanning electron microscopy
• stored grain
• xerophilic species

Acknowledgments

This work was supported by the Grant Agency of the Czech Republic P506/12/1064, institutional resources of Ministry of Education, Youth and Sports of the Czech Republic for the support of science and research and Charles University Research Project No. 267208/13. Molecular genetic analyses were supported by project GAUK 607812. Prof Jiří Váňa and Prof Karol Marhold are gratefully acknowledged for consultation on nomenclatural changes. We thank Blanka Šrámková, Dr Pavlína Lysková, Dr Magdalena Skořepová, Dr Alena Nováková, Dr Jiří Řehulka, Dr Monika Laichmanová and Dr Naďa Mallátová for supplying isolates. We also thank Dr Miroslav Hyliš for help with scanning electron microscopy, Dr Milada Chudíčková for isolation of DNA and Dagmar Kozáková for lyophilization of the cultures. We are grateful to Dr Bruce W. Horn for careful editing.

Notes

a White sporulating mutants have been reported in A. niveoglaucus. No reliable feature was found to differentiate green sporulating isolates of A. glaucus and A. niveoglaucus; sequences of all four loci examined unambiguously distinguish both species.