The Production of Spores by Penicillium notatum

Abstract

Summary: Penicillium notatum gives high yields of spores on media containing carbohydrates, ammonia and an organic acid such as citric, tartaric, or succinic acid. The media are similar to those which are good for the production of penicillin, but the choice of organic acids is less restricted. Of physical factors influencing the yield of spores the most interesting was variation in the volume of medium. Within certain limits the number of spores produced depended almost entirely on the volume of the medium and not on the surface area; i.e. the yield of spores/unit area depended on the depth of the medium. An increase in the concentration of metabolites above normal level did not greatly increase the yield of spores, and the addition of further nutrients to a previously used medium gave only a small second crop. The production of spores therefore appeared to be limited by the accumulation of toxic substances in the medium.