School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China.
School of Life Sciences, Guangzhou University, 230 Wai Huan Xi Road, Guangzhou 510006, China.
J Agric Food Chem. 2024 Jun 26;72(25):14264-14273. doi: 10.1021/acs.jafc.4c03348. Epub 2024 Jun 11.
Ergothioneine (EGT) is a naturally occurring derivative of histidine with diverse applications in the medicine, cosmetic, and food industries. Nevertheless, its sustainable biosynthesis faces hurdles due to the limited biosynthetic pathways, complex metabolic network of precursors, and high cost associated with fermentation. Herein, efforts were made to address these limitations first by reconstructing a novel EGT biosynthetic pathway from in and optimizing it through plasmid copy number. Subsequently, the supply of precursor amino acids was promoted by engineering the global regulator, recruiting mutant resistant to feedback inhibition, and blocking competitive pathways. These metabolic modifications resulted in a significant improvement in EGT production, increasing from 35 to 130 mg/L, representing a remarkable increase of 271.4%. Furthermore, an economical medium was developed by replacing yeast extract with corn steep liquor, a byproduct of wet milling of corn. Finally, the production of EGT reached 595 mg/L with a productivity of 8.2 mg/L/h by exploiting fed-batch fermentation in a 10 L bioreactor. This study paves the way for exploring and modulating a de novo biosynthetic pathway for efficient and low-cost fermentative production of EGT.
ergothioneine（EGT）是组氨酸的一种天然衍生化合物，在医学、化妆品和食品工业中有广泛的应用。然而，由于其生物合成途径有限、前体代谢网络复杂以及发酵成本高，其可持续生物合成仍面临诸多挑战。在此，我们首先通过在 中重建一条新型 EGT 生物合成途径，并通过质粒拷贝数对其进行优化，来解决这些限制。随后，通过工程全局调控因子、招募对反馈抑制有抗性的突变体以及阻断竞争途径来促进前体氨基酸的供应。这些代谢修饰使 EGT 的产量显著提高，从 35mg/L 增加到 130mg/L，增加了 271.4%。此外，我们还通过用玉米浸出液（玉米湿法加工的副产物）替代酵母提取物来开发经济的培养基。最后，通过在 10L 生物反应器中利用分批补料发酵，EGT 的产量达到了 595mg/L，生产强度为 8.2mg/L/h。本研究为探索和调节新型从头生物合成途径以实现高效、低成本的 EGT 发酵生产铺平了道路。
