Simultaneous production and partitioning of heterologous polyketide and isoprenoid natural products in an Escherichia coli two-phase bioprocess
Natural products have long served as rich sources of drugs possessing a wide range of pharmacological activities. The discovery and development of natural product drug candidates is often hampered by the inability to efficiently scale and produce a molecule of interest, due to inherent qualities of the native producer. Heterologous biosynthesis in an engineering and process-friendly host emerged as an option to produce complex natural products. Escherichia coli has previously been utilized to produce complex precursors to two popular natural product drugs, erythromycin and paclitaxel. These two molecules represent two of the largest classes of natural products, polyketides and isoprenoids, respectively. In this study, we have developed a platform E. coli strain capable of simultaneous production of both product precursors at titers greater than 15 mg l−1. The utilization of a two-phase batch bioreactor allowed for very strong in situ separation (having a partitioning coefficient of greater than 5,000), which would facilitate downstream purification processes. The system developed here could also be used in metagenomic studies to screen environmental DNA for natural product discovery and preliminary production experiments.
KeywordsHeterologous host Escherichia coli Polyketide Isoprenoid Two-phase bioreactor
The authors recognize support from the National Institutes of Health (GM085323) and the Milheim Foundation (Grant for Cancer Research No. 2006-17). MM was supported through the Tufts University Summer Scholars program. JW was supported through the Chinese Scholarship Council as a visiting student from East China University of Science and Technology.
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