Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2003
Publication Date: 7/1/2003
Citation: Cary, J.W., Beltz, S.B., Klich, M.A. 2003. Characterization of aflatoxin-producing fungi outside of Aspergillus section flavi [abstract]. American Society for Microbiology Annual Meeting, New Orleans, Louisiana.
Technical Abstract: Aflatoxin is a carcinogenic secondary metabolite produced by the agriculturally important species Aspergillus flavus and A. parasiticus and several closely related species in Aspergillus section Flavi. Recently, several rare Aspergillus species not closely related to A. flavus have been found to produce aflatoxin, including one we report for the first time here, A. astellatus (Emericella astellata). Characterization of these fungi will help to elucidate why aflatoxin is formed and how aflatoxin production evolved. In this study, we obtained morphological and ecological data on each of the aflatoxin-producing isolates and performed a phylogenetic analysis using aflatoxin biosynthetic and housekeeping genes to compare these species to the well-characterized species A. flavus and A. nidulans. (A. nidulans produces a closely related metabolite, sterigmatocystin). Our results showed that: 1) all of the aflatoxin producers outside of section Flavi were from tropical/subtropical habitats near oceans; 2) none of the isolates grew at 37 C; and, 3) phylogenetically, the aflatoxin genes of these species are more closely related to the sterigmatocystin biosynthesis genes of A. nidulans than the aflatoxin biosynthesis genes of A. parasiticus.