Production of the mycotoxin cyclopiazonic acid by Penicillium commune on solid agar media: Effects of water activity, temperature, and incubation time

The combined effects of water activity (aw), temperature, incubation time, and medium composition on cyclopiazonic acid (CPA) production by an isolate of Penicillium commune was studied using a full-factorial experimental design. An analysis of variance for the mycotoxin showed that there was a complex interaction between all these factors and that this affected the production of CPA. The minimum aw for CPA production (0.025 to 0.238 μg ml−1) in yeast extract agar was 0.90 whereas in Czapek yeast autolysate agar it was 0.85 (0.048 to 0.123 μg ml−1). The temperature range for CPA production was 20 to 30°C. The optimum temperature for CPA production was 25°C. CPA was maximally produced (3.199 to 3.993 μg ml−1) at an aw of 0.996 after 15 days of incubation.