Production of Patulin in Apple Fruits by Penicillium expansum

Abstract

IT has been thought unlikely that antibiotics are produced under natural conditions, (a) because the necessary nutrients would not usually be available and (b) because other micro-organisms might be expected to compete for nutrients and, in some cases, to destroy metabolically any antibiotic formed. Nevertheless, a plant parasite may have access to a relatively rich nutrient supply and may be, in early stages of an infection at least, isolated from the influence of other micro-organisms. Penicillium expansum is an unspecialized plant parasite, causing storage rots of apples; most freshly isolated strains produce the antibiotic patulin (synonyms : clavacin, expansine) in suitable culture media. We thought it of interest to see whether it produces patulin in apple tissues.