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Abstract: Resveratrol is a unique, natural polyphenolic compound with diverse health benefits. In the present study, we attempted to improve resveratrol biosynthesis in yeast by different methods of metabolic engineering. We first mutated and then re-synthesized tyrosine ammonia lyase (TAL) by replacing the bacteria codons with yeast-preferred codons, which increased translation and improved p-coumaric acid and resveratrol biosynthesis drastically. We then demonstrated that low-affinity, high-capacity bacterial araE transporter could enhance resveratrol accumulation, without transporting resveratrol directly. Yeast cells carrying the araE gene produced up to 2.44-fold higher resveratrol than control cells. For commercial applications, resveratrol biosynthesis was detected in sucrose medium and fresh grape juice using our engineered yeast cells. In collaboration with the Chaumette Winery of Missouri, we were able to produce resveratrol-containing white wines, with levels comparable to the resveratrol levels found in most red wines. [Copyright &y& Elsevier]

Resveratrol, a compound commonly found in red wine, has attracted many attentions recently. It is a diphenolic natural product accumulated in grapes and a few other species under stress conditions. It possesses a special ability to increase the life span of eukaryotic organisms, ranging from yeast, to fruit fly, to obese mouse. The demand for resveratrol as a food and nutrition supplement has increased significantly in recent years. Extensive work has been carried out to increase the production of resveratrol in plants and microbes. In this review, we will discuss the biosynthetic pathway of resveratrol and engineering methods to heterologously express the pathway in various organisms. We will outline the shortcuts and limitations of common engineering efforts. We will also discuss briefly the features and engineering challenges of other longevity boosting compounds. [ABSTRACT FROM AUTHOR]

Abstract: Resveratrol is a polyphenolic compound produced by a few higher plants when under attack by pathogens such as bacteria or fungi. Besides antioxidant benefits to humans, this health-promoting compound has been reported to extend longevity in yeasts, flies, worms, fishes and obesity mice. Here we utilized the synthetic scaffolds strategy to improve resveratrol production in Saccharomyces cerevisiae. We observed a 5.0-fold improvement over the non-scaffolded control, and a 2.7-fold increase over the previous reported with fusion protein. This work demonstrated the synthetic scaffolds can be used for the optimization of engineered metabolic pathway. [Copyright &y& Elsevier]

• Yarrowia has shown the potential for producing complex terpenoids. • Yarrowia may hold multiple cytosolic acetyl-CoA and NADPH generation pathways. • Metabolite channeling is a key consideration in terpene pathway engineering. • Knowledge gaps exist in compartment-specific fluxes for utilizing alternative carbon sources (e.g., lipids). • Metabolic shift, genetic stability, and dimorphism in large-scale Yarrowia fermentation need further studies. Yarrowia lipolytica has emerged as an important non-model host for terpene production. However, three main challenges remain in industrial production using this yeast. First, considerable knowledge gaps exist in metabolic flux across multiple compartments, cofactor generation, and catabolism of non-sugar carbon sources. Second, many enzymatic steps in the complex-terpene synthesis pathway can pose rate-limitations, causing accumulation of toxic intermediates and increased metabolic burdens. Third, metabolic shifts, morphological changes, and genetic mutations are poorly characterized under industrial fermentation conditions. To overcome these challenges, systems metabolic analysis, protein engineering, novel pathway engineering, model-guided strain design, and fermentation optimization have been attempted with some successes. Further developments that address these challenges are needed to advance the Yarrowia lipolytica platform for industrial-scale production of high-value terpenes, including those with highly complex structures such as anticancer molecules withanolides and insecticidal limonoids. [ABSTRACT FROM AUTHOR]

Summary: As the second enzyme of the non-mevalonate terpenoid pathway for isopentenyl diphosphate biosynthesis, DXP reductoisomerase (DXR, EC: 1.1.1.267) catalyzes a committed step of the MEP pathway for camptothecin (CPT) biosynthesis. In order to understand more about the role of DXR involved in the CPT biosynthesis at the molecular level, the full-length DXR cDNA sequence (designated as CaDXR) was isolated and characterized for the first time from a medicinal Nyssaceae plant species, Camptotheca acuminata. The full-length cDNA of CaDXR was 1823bp containing a 1416bp open reading frame (ORF) encoding a polypeptide of 472 amino acids. Comparative and bioinformatic analyses revealed that CaDXR showed extensive homology with DXRs from other plant species and contained a conserved transit peptide for plastids, an extended Pro-rich region and a highly conserved NADPH binding motif in its N-terminal region owned by all plant DXRs. Phylogenetic analysis indicated that CaDXR was more ancient than other plant DXRs. Tissue expression pattern analysis revealed that CaDXR expressed strongly in stem, weak in leaf and root. CaDXR was found to be an elicitor-responsive gene, which could be induced by exogenous elicitor of methyl jasmonate. The functional color complementation assay indicated that CaDXR could accelerate the biosynthesis of carotenoids in the Escherichia coli transformant, demonstrating that DXP reductoisomerase plays an influential step in isoprenoid biosynthesis. [Copyright &y& Elsevier]