Kallscheuer Nicolai, Vogt Michael, Marienhagen Jan
Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich , D-52425 Jülich, Germany.
ACS Synth Biol. 2017 Mar 17;6(3):410-415. doi: 10.1021/acssynbio.6b00291. Epub 2016 Dec 14.
Numerous plant polyphenols have potential applications as pharmaceuticals or nutraceuticals. Stilbenes and flavonoids as most abundant polyphenols are synthesized from phenylpropanoids, which are exclusively derived from aromatic amino acids in nature. Several microorganisms were engineered for the synthesis of biotechnologically interesting plant polyphenols; however, low activity of heterologous ammonia lyases, linking endogenous microbial aromatic amino acid biosynthesis to phenylpropanoid synthesis, turned out to be the limiting step during microbial synthesis. We here developed an alternative strategy for polyphenol production from cheap benzoic acids by reversal of a β-oxidative phenylpropanoid degradation pathway avoiding any ammonia lyase activity. The synthetic pathway running in the non-natural direction is feasible with respect to thermodynamics and involved reaction mechanisms. Instantly, product titers of 5 mg/L resveratrol could be achieved in recombinant Corynebacterium glutamicum strains indicating that phenylpropanoid synthesis from 4-hydroxybenzoic acid can in principle be implemented independently from aromatic amino acids and ammonia lyase activity.
许多植物多酚作为药物或营养保健品具有潜在应用价值。作为最丰富的多酚类物质，芪类和黄酮类化合物由苯丙烷类合成，而苯丙烷类在自然界中仅来源于芳香族氨基酸。几种微生物已被改造用于合成具有生物技术意义的植物多酚；然而，将内源性微生物芳香族氨基酸生物合成与苯丙烷类合成相连接的异源氨裂解酶活性较低，这成为微生物合成过程中的限制步骤。我们在此开发了一种替代策略，通过逆转β-氧化苯丙烷类降解途径，从廉价的苯甲酸生产多酚，避免任何氨裂解酶活性。在非自然方向运行的合成途径在热力学和涉及的反应机制方面是可行的。即刻，在重组谷氨酸棒杆菌菌株中可实现5 mg/L白藜芦醇的产物滴度，这表明从4-羟基苯甲酸合成苯丙烷类原则上可以独立于芳香族氨基酸和氨裂解酶活性来实现。
