Heterologous erythromycin production across strain and plasmid construction.

The establishment of erythromycin production within the heterologous host E. coli marked an accomplishment in genetic transfer capacity. Namely, over 20 genes and 50 kb of DNA was introduced to E. coli for successful heterologous biosynthetic reconstitution. However, the prospect for production levels that approach those of the native host requires the application of engineering tools associated with E. coli. In this report, metabolic and genomic engineering were implemented to improve the E. coli cellular background and the plasmid platform supporting heterologous erythromycin formation. Results include improved plasmid stability and metabolic support for biosynthetic product formation. Specifically, the new plasmid design for erythromycin formation allowed for ≥89% stability relative to current standards (20% stability). In addition, the new strain (termed LF01) designed to improve carbon flow to the erythromycin biosynthetic pathway provided a 400% improvement in titer level.