Effects of gamma radiation on growth and patulin production of Penicillium expansum and Penicillium patulim

Abstract

The spore suspensions of Penicillium expansum NRRL 971 and Penicillium patulum NRRL 989 were exposed to doses of 0, 50, 100, 150, and 200 krads. The amount of patulin for each culture was semi quantitatively determined and growth at each dose was evaluated. The results showed a 25% increase in the amount of patulin synthesis after a dose of 150 krads for Penicillium expansum. No stimulation of patulin production by Penicillium patulum occurred. At 200 krads, both fungi showed low levels of patulin production and growth inhibition. Eight color mutants of Penicillium expansum and eight color mutants of Penicillium patulum were produced by exposing spores of each fungus to doses of 150 and 200 krads of gamma radiation. An evaluation of patulin and growth for each mutant showed that color mutation could result in mutants with an enhanced ability to grow or produce increased levels of patulin.