The genetic and biochemical basis of polyketide metabolism in microorganisms and its role in drug discovery and development.

The possibilities for the design of new drug screening and development strategies directed to a specific objective on the basis of genetic engineering of microorganisms is discussed from two points of view. Firstly, results of work on genetic hybrids of STREPTOMYCES species for the production of new metabolites such as mederrhodin (1) and aloespanoarin II (4) are described. Secondly, the enhanced production of known metabolites such as tetracenomycin A (2) (11) and tetracenomycin C (9) by recombinant STREPTOMYCES species is considered. Mechanistic aspects of polyketide metabolism are included.