Influence of medium design on lovastatin and mevastatin production by Aspergillus terreus strains

In order to investigate the influence of medium design on lovastatin and mevastatin production by Aspergillus terreus strains, several nitrogen complex sources, such as vegetal flour and peptones of different origin (animal and vegetal) were tested, together with the addition of methionine, an aminoacid that is directly involved in lovastatin biosynthetic pathway. Soybean peptone generally allowed the best lovastatin yields to be achieved (250-280 mg l(-1)), particularly in the presence of soybean and peanut flours. For mevastatin, the best results (300-320 mg l(-1)) were obtained at 7 days fermentation with modified base medium (CLD), and at 14 days with standard medium (STD), not being possible in this case to associate the best yield with a defined flour and/or peptone. The results show that lovastatin production is influenced by the presence of soybean peptone and by the addition of methionine; instead, the production of mevastatin appears more strictly strain-associated and not directly dependent on the complex ingredients employed.