Mutation Breeding and Mutagenic Effect of Air Plasma on Penicillium chrysogenum

Treatment by low temperature air plasma was adopted as the mutation approach for penicillin-producing strain Penicillium chrysogenum, with discharge conditions of a rf power of 360 W, a temperature of 40 °C in a sealed chamber and a pressure of 10 to 30 Pa. The result showed that the kinetics of the survival rate followed a typical saddle-shaped curve. Based on a statistic analysis, at a treating duration of 10 min, the positive mutation rate was as high as 37.5 % while the negative mutation rate was low. The colonial morphology changed obviously when the plasma treating duration reached 45 min or longer. After primary and secondary screening, a mutant designated as aPc051310 with high productivity of penicillin was obtained and the strong mutagenic effect on P. chrysogenum was reflected in the process. It was proved that after five generations the mutant aPc051310 still maintained high productivity. All the results prove that the plasma mutation method could be developed as a convenient and effective tool for breeding high-yield strains in the fermentation industry, while extending the application areas of plasma are extended simultaneously.