Isoflavonoid production by genetically engineered microorganisms

Isoflavonoids are a class of plant natural products gaining attention due to their pharmaceutical properties. These natural compounds constitute a subclass of flavonoids, which belong to a broader class of plant products known as phenylpropanoids. Flavonoids have been associated with medicinal properties, while isoflavonoids have shown anticancer, antioxidant, and cardioprotective properties due to their role as inhibitors of estrogen receptors. Isoflavonoids are naturally produced by legumes and, more specifically, organisms belonging to the pea family. Harvesting of these natural products through traditional extraction processes is limited due to the low levels of these phytochemicals in plants, so alternative production platforms are required to reduce cost of production and increase availability. Over the last decade, researchers have engineered artificial flavonoid biosynthesis pathways into Escherichia coli and Saccharomyces cerevisiae to convert simple, renewable sugars like glucose into flavonoids at high production levels. This chapter outlines the metabolic engineering research that has enabled microbial production of plant flavonoids and further details the ongoing work aimed at producing both natural and non-natural isoflavonoids in microorganisms.