Penicillium expansum

Penicillium expansum is one of the most prevalent post harvest rots that infects apples.

Although it is a major economical problem in apples, this plant pathogen can be isolated from a wide host range, including pears, strawberries, tomatoes, corn, and rice. This mold also produces the carcinogenic metabolite patulin, a neurotoxin that is harmful in apple juice and apple products. Patulin is produced by the fungi when it rots the host. The levels of patulin in food products is a health concern because many are consumed by young children. In addition, a second secondary metabolite citrinin is produced as well. Furthermore, it is also one of the oldest known species of Penicillium recorded and has been used for continuous research and studies. It is a psychrophilic blue mold and ubiquitous throughout the soil.