(191bf) Next Steps in Engineering E. coli Erythromycin Production

Erythromycin has been widely used to against bacterial infections. Instead of using the original producing host Saccharopolyspora erythraea (S. erythraea), here we harness Escherichia coli (E. coli) as an expression surrogate due to the relative ease of genetic manipulation. A recent version of the production system features five plasmids hosting large (~55 kb) heterologous expression pathway. In this work, we’ve improved the strain stability by rearranging the expression pathway. Two bacterial artificial chromosomes(BAC) were employed rather than our previous five plasmids to reduce cell metabolic burden and improve efficiency. We also improved erythromycin titers by accumulating the common deoxysugar intermediate TDP-4-keto-deoxyglucose. Additionally, an E. coli multidrug efflux pump (MacAB) was overexpressed to further elevated erythromycin titer. Finally, six heterologously expressed deoxysugars were studied to biosynthesize erythromycin analogous in this study.