Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, 1000 Ljubljana, Slovenia.
Department of Biotechnology and Biomedicine, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
Department of Biology, University of Ottawa, 30 Marie-Curie, Ottawa, ON K1N 6N5, Canada.
Biodiversity (Mycology), Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada.
Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, PR China.
Université de Brest, EA3882 Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France.
Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, IL 61604, USA.
First Faculty of Medicine, Charles University, Kateřinská 32, 121 08 Prague 2, Czech Republic.
Aspergillus section Restricti together with sister section Aspergillus (formerly Eurotium) comprises xerophilic species, that are able to grow on substrates with low water activity and in extreme environments. We adressed the monophyly of both sections within subgenus Aspergillus and applied a multidisciplinary approach for definition of species boundaries in sect. Restricti. The monophyly of sections Aspergillus and Restricti was tested on a set of 102 isolates comprising all currently accepted species and was strongly supported by Maximum likelihood (ML) and Bayesian inferrence (BI) analysis based on β-tubulin (benA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) loci. More than 300 strains belonging to sect. Restricti from various isolation sources and four continents were characterized by DNA sequencing, and 193 isolates were selected for phylogenetic analyses and phenotypic studies. Species delimitation methods based on multispecies coalescent model were employed on DNA sequences from four loci, i.e., ID region of rDNA (ITS + 28S), CaM, benA and RPB2, and supported recognition of 21 species, including 14 new. All these species were also strongly supported in ML and BI analyses. All recognised species can be reliably identified by all four examined genetic loci. Phenotype analysis was performed to support the delimitation of new species and includes colony characteristics on seven cultivation media incubated at several temperatures, growth on an osmotic gradient (six media with NaCl concentration from 0 to 25 %) and analysis of morphology including scanning electron microscopy. The micromorphology of conidial heads, vesicle dimensions, temperature profiles and growth parameters in osmotic gradient were useful criteria for species identification. The vast majority of species in sect. Restricti produce asperglaucide, asperphenamate or both in contrast to species in sect. Aspergillus. Mycophenolic acid was detected for the first time in at least six members of the section. The ascomata of A. halophilicus do not contain auroglaucin, epiheveadride or flavoglaucin which are common in sect. Aspergillus, but shares the echinulins with sect. Aspergillus.
Keywords: Aspergillus canadensis Visagie, Yilmaz, F. Sklenar & Seifert; Aspergillus clavatophorus F. Sklenar, S.W. Peterson & Hubka; Aspergillus destruens Zalar, F. Sklenar, S.W. Peterson & Hubka; Aspergillus domesticus F. Sklenar, Houbraken, Zalar & Hubka; Aspergillus glabripes F. Sklenar, Ž. Jurjević & Hubka; Aspergillus hordei F. Sklenar, S.W. Peterson & Hubka; Aspergillus infrequens F. Sklenar, S.W. Peterson & Hubka; Aspergillus magnivesiculatus F. Sklenar, Zalar, Ž. Jurjević & Hubka; Aspergillus pachycaulis F. Sklenar, S.W. Peterson, Ž. Jurjević & Hubka; Aspergillus penicillioides; Aspergillus pseudogracilis F. Sklenar, Ž. Jurjević & Hubka; Aspergillus restrictus; Aspergillus reticulatus F. Sklenar, Ž. Jurjević, S.W. Peterson & Hubka; Aspergillus salinicola Zalar, F. Sklenar, Visagie & Hubka; Aspergillus tardicrescens F. Sklenar, Houbraken, Zalar, & Hubka; Aspergillus villosus F. Sklenar, S.W. Peterson & Hubka; Eurotium; food spoilage; indoor fungi; linear discriminant analysis; multigene phylogeny; multispecies coalescent model; sick building syndrome; xerophilic fungi
