Efficient experimental design and micro‐scale medium enhancement of 6‐deoxyerythronolide B production through Escherichia coli

The recent use of heterologous hosts to produce natural products has shown significant potential, although limitations still exist regarding optimal production titers. In this study, we utilize micro‐scale cultures and well‐defined screening methods to identify key medium components that influence the heterologous production of the complex polyketide 6‐deoxyerythronolide B (6dEB) through E. coli. It was determined that tryptone had a significant effect on 6dEB production and could supplement substrate requirements and improve recombinant protein levels of the essential deoxyerythronolide B synthase (DEBS) which catalyze 6dEB conversion. As a result, the study (1) demonstrates the feasibility of micro‐scale cultures to study E. coli 6dEB production and effectively model larger‐scale cultures; (2) identifies an enhanced medium which generates over 160 mg L^?1 6dEB (a 22‐fold improvement over current culture media); and (3) provides new insight and understanding related to the heterologous production of 6dEB from E. coli. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009