Abstract
BackgroundResveratrol is a plant secondary metabolite with diverse, potential health-promoting benefits. Due to its nutraceutical merit, bioproduction of resveratrol via microbial engineering has gained increasing attention and provides an alternative to unsustainable chemical synthesis and straight extraction from plants. However, many studies on microbial resveratrol production were implemented with the addition of water-insoluble phenylalanine or tyrosine-based precursors to the medium, limiting in the sustainable development of bioproduction.ResultsHere we present a novel coculture platform where two distinct metabolic background species were modularly engineered for the combined total and de novo biosynthesis of resveratrol. In this scenario, the upstream Escherichia coli module is capable of excreting p-coumaric acid into the surrounding culture media through constitutive overexpression of codon-optimized tyrosine ammonia lyase from Trichosporon cutaneum (TAL), feedback-inhibition-resistant 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (aroGfbr) and chorismate mutase/prephenate dehydrogenase (tyrAfbr) in a transcriptional regulator tyrR knockout strain. Next, to enhance the precursor malonyl-CoA supply, an inactivation-resistant version of acetyl-CoA carboxylase (ACC1S659A,S1157A) was introduced into the downstream Saccharomyces cerevisiae module constitutively expressing codon-optimized 4-coumarate-CoA ligase from Arabidopsis thaliana (4CL) and resveratrol synthase from Vitis vinifera (STS), and thus further improve the conversion of p-coumaric acid-to-resveratrol. Upon optimization of the initial inoculation ratio of two populations, fermentation temperature, and culture time, this co-culture system yielded 28.5 mg/L resveratrol from glucose in flasks. In further optimization by increasing initial net cells density at a test tube scale, a final resveratrol titer of 36 mg/L was achieved.ConclusionsThis is first study that demonstrates the use of a synthetic E. coli–S. cerevisiae consortium for de novo resveratrol biosynthesis, which highlights its potential for production of other p-coumaric-acid or resveratrol derived biochemicals.
Highlights
Resveratrol is a plant secondary metabolite with diverse, potential health-promoting benefits
Resveratrol synthesis requires 4-coumaroyl-CoA whose biosynthesis starts with the conversion of phenylalanine and tyrosine into the phenylpropanoid acids cinnamic acid and p-coumaric acid, respectively [15]
These reactions are catalyzed by phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) enzymes with some promiscuous crossreactivity known to be present [16]
Summary
Resveratrol is a plant secondary metabolite with diverse, potential health-promoting benefits. Resveratrol synthesis requires 4-coumaroyl-CoA whose biosynthesis starts with the conversion of phenylalanine and tyrosine into the phenylpropanoid acids cinnamic acid and p-coumaric acid, respectively [15]. These reactions are catalyzed by phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) enzymes with some promiscuous crossreactivity known to be present [16]. One standout report for de novo production from glucose and ethanol was achieved in S. cerevisiae CEN.PK102-5B [10, 11] whereby extensive engineering of the tyrosine pathway along with complementation of resveratrol biosynthetic genes (TAL from H. aurantiacus, 4CL from A. thaliana and STS from V. vinifera) led to a resveratrol titer of 416 and 531 mg/L from glucose and ethanol, respectively, in fed-batch fermentation [10]. Further improvements were made by using the phenylalanine pathway to achieve a final titer of 812 and 755 mg/L resveratrol from glucose and ethanol feed, respectively, in fed-batch mode [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
