This Phase I project will develop a recombinant system to stably clone and express multigene pathways encoding bioactive compounds. Due to the proliferation of antibiotic resistant strains of microbial pathogens and to demographic shifts the need for novel antibiotics, anticancer agents and other compounds greatly exceeds the present discovery rate despite recent increases in the screening efforts and the development of combinatorial techniques. A vast repository of pathways encoding potentially useful bioactive compounds resides within the uncultivated fraction of naturally occurring microbes; however, approaches to date have not successfully accessed this resource. As a first stem towards this goal, in Phase l a shuttle vector system will be developed based on an F factor replicon for stable propagation of clones in E coli and containing genes/sites for replication or integration in Streptomyces to express pathways encoding known polyketide antibiotics. In Phase II, these vectors will be used to construct "environmental libraries" containing the collective genomes of uncultivated microbes captured in substrate-doped traps designed to attract actinomycetes and other microbes likely to produce novel bioactive compounds. PROPOSED COMMERCIAL APPLICATION: This work will lead to the discovery of novel bioactive compounds including antibiotics, anti-infectives, anti-cancer and anti-inflammatory agents.