Abstract
The fungal genus Penicillium , comprising more than 350 species, has been known worldwide since Alexander Fleming’s groundbreaking discovery of penicillin in 1928. However, it took many years of intensive research before enough penicillin could be produced for medical use. Today, both genetic engineering and conventional methods are available for improving fungal production strains. These include breeding technologies that became possible after the discovery of a sexual cycle in P. chrysogenum .