Influence of carbohydrate and nitrogen source on patulin production by Penicillium patulum

A strain of Penicillium patulum, isolated from cheddar cheese, produced patulin when grown on liquid media containing lactose and milk nitrogen sources. Patulin production was affected by the temperature of incubation, the type and amount of carbohydrate, and the type of nitrogen source present. Patulin levels generally were depressed by incubation at 5 C and low carbohydrate levels. Patulin was produced at low levels in the absence of sugars at 5 C when the mold was grown on milk nitrogen sources. No patulin was detected in cultures grown on 25% casein slurries or cheddar cheese, even though growth of the mold was extensive.