Biosynthesis of Polyphenols in Recombinant Micro‐organisms

Polyphenols in general and flavonoids in particular are important bioactive compounds obtained naturally from plants that confer health-promoting and medical benefits to humans. There is an increasing global demand for plant polyphenols, especially in the food and drug industries due to their immense pharmaceutical and nutraceutical values and limited side effects. However, supply limitations due to strict metabolic regulation in plants, seasonal changes and extraction difficulties of these compounds from their natural plant sources restrict their large-scale use. Metabolic engineering via microbial platforms has been advanced as a cost-effective and eco-friendly alternative approach for production of value-added polyphenols from simple carbon sources. Amenability to genetic manipulation, controllability and scalability of the fermentation processes make microbes a potential platform for industrial production of these compounds. In addition to increasing product yield, microbial platforms also provide an opportunity for the synthesis of novel derivatives of natural products that may have higher efficiency and new functions. This chapter highlights progress and challenges in the biological production of value-added polyphenols via metabolic engineering approaches.