EFFECTS OF DIFFERENT CEREAL AND OILSEED SUBSTRATES ON THE GROWTH AND PRODUCTION OF TOXINS BY ASPERGILLUS-ALUTACEUS AND PENICILLIUM-VERRUCOSUM

Cereal substrates (corn and wheat) and oilseeds (peanut, rapeseed, and soybean) were evaluated for their ability to support the production of ochratoxin A (OA), ochratoxin B (OB), and citrinin by Aspergillus alutaceus (formerly ochraceus) and Penicillium verrucosum over different periods of time (7, 15, and 30 days). Peanut and soybean supported the production of fungal biomass (26 and 6 mg/g glucosamine, respectively), OA (345 and 243 µg/g, respectively), and OB (130 and 390 µg/g, respectively) by A. alutaceus better than other substrates after 30 days of incubation, while corn and wheat did not support OB production during this time period. P. verrucosum produced higher amounts of fungal biomass and OA on wheat (10 mg/g glucosamine and 97 µg/g OA) than other substrates after 30 days. Corn and wheat supported citrinin production by P. verrucosum (124 and 102 µg/g, respectively, after 30 days) while oilseeds did not. Thus, substrates in addition to type of fungi have a dramatic influence on the nature and amount of toxic metabolites produced. Furthermore, this appears to be the first report of OB production in oilseeds. © 1990, American Chemical Society. All rights reserved.