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United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPMENT AND APPLICATION OF MOLECULAR PHYLOGENETICS OF FUNGI TO ENHANCE FOOD SAFETY AND FOOD SECURITY

Location: Bacterial Foodborne Pathogens & Mycology Research Unit

Title: Phylogenetic analysis of Aspergillus species using DNA sequences from four loci

Author
item Peterson, Stephen

Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 7, 2008
Publication Date: June 1, 2008
Citation: Peterson, S.W. 2008. Phylogenetic analysis of Aspergillus species using DNA sequences from four loci. Mycologia. 100(2):205-226.

Interpretive Summary: Identification of fungi has historically been performed by visual and microscopic examination of cultures, but authorities have differed in how they define the species and the process is time consuming. Because some molds are used in food fermentations and other molds may cause storage losses in commodities, it is necessary that molds be correctly identified. DNA sequences were made from all species of the mold group Aspergillus, and the data were analyzed to find species limits. The database of DNA sequences provides the information needed to design DNA probes that can be used for rapid identification of species. Use of DNA sequences for identification will increase the speed of identification while assuring better accuracy, helping to assure the highest quality commodities and allowing monitoring of the purity of fungi used in food fermentations. Benefits will be to ARS and university scholars conducting toxicology studies or ecological studies, potentially to manufacturers of fermented foods, and to medical personnel who need rapid identifications of fungi involved in human infections.

Technical Abstract: DNA was isolated from representatives of Aspergillus species and sequences were determined for beta tubulin, calmodulin, ITS and lsu rDNA and RNA polymerase. The sequences were analyzed phylogenetically using PAUP* and MRBayes and species boundaries were assessed using genealogical concordance analysis. Aspergillus crystallinus, A. malodoratus and Hemicarpenteles paradoxus were part of the Eupenicillium clade. Other species such as Warcupiella spinulosa, A. zonatus and Sclerocleista spp. did not fall within the main Aspergillus branch. The branching order leading to sections of Aspergillus was not fully resolved, but a number of strongly supported relationships were found. Dichotomomyces cejpii, a species with Polypaecillum anamorph was closely related to species from section Clavati. The sequences from beta tubulin, calmodulin or RNA polymerase are sufficiently variable to find short DNA sequences that are species specific.

Last Modified: 9/10/2014
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