A primary goal of our natural products research is to get further insights into the secondary metabolism of microorganisms and to generate a novel diversity of secondary metabolites. The research is based on previous work with biological derivatisation methods to enhance the diversity of secondary metabolites from microorganisms. We are interested in a new approach to novel metabolites by extension to genetic studies in interdisciplinary projects. Regulation acitivties concerning differentiation mechanisms and the investigation of the biosynthesis of metabolites is of our interest. For our aims Aspergillus sp., Streptomyces sp. and some other microorganisms with marked differentiation activities are selected.