2008 Annual Report
The systematics and taxonomy of the ochratoxin-A producing species from Aspergillus section Circumdati (the Aspergillus ochraceus group) was assessed using multilocus DNA sequence analysis. Additional species have been identified from section Cirdumdati that were not previously known. Some of the these species are non-ochratoxigenic, whereas others make ochratoxin-A. Having established the species that exist in section Circumdati, it is now possible to prepare oligonucleotide probes to rapidly identify each of the ochratoxigenic species. Collaborative studies are underway to determine the characters that can be used to describe and distinguish these species from others in the section. The ochratoxigenic species from section Nigri (the Aspergillus niger group) were also examined. Suprisingly, the beta-tubulin locus typically used to assess relationships and species boundaries in this group of fungi was found to occur as one of two unrelated forms (paralogs).
A multigene sequence analysis of the approximately 150 known species of Pichia, Debaryomyces, Dekkera and Brettanomyces provided the basis for reassigning species to phylogenetically defined genera, resulting in the proposal of eight new genera (Babjeviella, Barnettozyma, Lindnera, Meyerozyma, Millerozyma, Priceomyces, Scheffersomyces, Wickerhamomyces), redefinition of four previously described genera (Debaryomyces, Pichia, Schwanniomyces, Yamadazyma), and the elimination of two genera (Issatchenkia, Williopsis). The taxonomic changes described provide a better understanding of species that cause food and beverage spoilage as well as those important to biotechnology and biocontrol. Species of the genus Metschnikowia, which are often used for biocontrol of fruit rots, were characterized from additional gene sequences.
This research directly addresses NP 108, Component 1.
5.Significant Activities that Support Special Target Populations
Kurtzman, C.P. 2007. Eleven new species of Sugiyamaella and Candida from forest habitats. Federation Of European Microbiological Societies Yeast Research. 7(6):1046-1063.
Elmer, W.H., Covert, S.F., O Donnell, K. 2007. Investigation of an outbreak of Fusarium foot and fruit rot of pumpkins within the United States. Plant Disease. 92:1142-1146.
Imamura, Y., Chandra, J., Mukherjee, P.K., Lattif, A., Szczotka-Flynn, L.B., Pearlman, E., Lass, J.H., O Donnell, K., Ghannoum, M.A. 2007. Fusarium and Candida albicans biofilms on soft contact lenses: model development, influence of lens type and susceptibility to lens care solutions. Antimicrobial Agents and Chemotherapy. 52:171-182.
Covert, S.F., Aoki, T., O Donnell, K., Starkey, D.E., Holliday, A., Geiser, D.M., Cheung, F., Town, C., Strom, A.L., Juba, A., Scandiani, M., Yang, X.B. 2007. Sexual reproduction in the soybean sudden death syndrome pathogen Fusarium tucumaniae. Fungal Genetics and Biology. 44(8):799-807.
Peterson, S.W., Varga, J., Frisvad, J.C., Samson, R.A. 2008. Phylogeny and subgeneric taxonomy of Aspergillus. In: Varga, J., Samson, R.A., editors. Wageningen Academic Publishers: Wageningen, The Netherlands. p. 33-56.
Torres, O.A., Palencia, E.R., Lopez de Pratdesaba, L., Grajeda, R., Fuentes, M., Speer, M.C., Merrill Jr, A.H., O Donnell, K., Bacon, C.W., Glenn, A.E., Riley, R.T. 2007. Estimated fumonisin exposure in Guatemala is greatest in consumers of lowland maize. Journal of Nutrition. 137:2723-2729.
Posada, F.J., Aime, M.C., Peterson, S.W., Rehner, S.A., Vega, F.E. 2007. Inoculation of coffee plants with the fungal entomopathogen Beauveria bassiana (Ascomycota: Hypocreales). Mycological Research. 111(6):748-757.
Starkey, D.E., Ward, T.J., Aoki, T., Gale, L.R., Kistler, H.C., Geiser, D.M., Suga, H., Toth, B., Varga, J., O Donnell, K. 2007. Global molecular surveillance reveals novel Fusarium head blight species and trichothecene toxin diversity. Fungal Genetics and Biology. 44(11):1191-1204.
Klich, M.A., Frisvad, J.C., Peterson, S.W., Varga, J., Geiser, D.M., Samson, R.A. 2007. The Current Status of Species Recognition and Identification in Aspergillus. Studies in Mycology. 59:1-10.
Horn, B.W., Peterson, S.W. 2008. Host specificity of Eupenicillium ochrosalmoneum, E. cinnamopurpureum and two Penicillium species associated with the conidial heads of Aspergillus. Mycologia 100(1):12-19.
Peterson, S.W. 2008. Phylogenetic analysis of Aspergillus species using DNA sequences from four loci. Mycologia. 100(2):205-226.
Ward, T.J., Clear, R.M., Rooney, A.P., O Donnell, K., Gaba, D., Patrick, S., Starkey, D.E., Gilbert, J., Geiser, D.M., Nowicki, T.W. 2008. An adaptive evolutionary shift in Fusarium head blight pathogen populations is driving the rapid spread of more toxigenic Fusarium graminerarum in North America. Fungal Genetics and Biology. 45(4):473-484.