Raising the production of phloretin by alleviation of by-product of chalcone synthase in the engineered yeast
Raising the production of phloretin by alleviation of by-product of chalcone synthase in the engineered yeast
复制标题
通过减少工程酵母中查尔酮合酶的副产物来提高根皮素的产量。
DOI：
10.1007/s11427-019-1634-8
复制
发表时间：
2020-04-27
影响因子：
9.1
通讯作者：
Wang, Wen
中科院分区：
文献类型：
--
作者：
Jiang, Chunmei;Liu, Xiaonan;Wang, Wen
Phloretin是一种重要的苹果皮美白脱色剂。虽然利用植物的自然途径在微生物中实现了根皮素的从头生产，但其生产效率仍不足以实现工业化应用。在这里，我们建立了一条在酵母中通过组装两个基因-p-香豆酰-辅酶A连接酶(4CL)和查尔酮合酶(CHS)来合成根癌菌素的人工途径。ChS是一种关键酶，它通常将辅酶A连接的发酵剂与三个丙二酰辅酶A分子缩合，形成类黄酮类化合物的骨架。然而，在发酵过程中，有33%的副产物是通过缩合两个丙二酰辅酶A产生的。因此，我们引入了更有效的CHS，并通过两条途径改善了丙二酰辅酶A的供应：副产率从33%降低到17%；根茎苷的产量从48 mg L-1提高到83.2 mg-1。最后对补料分批发酵工艺进行了优化，结果表明，根癌菌素的产量达到了619.5 mg L-1，比以往的研究提高了14倍。我们的工作为以低成本原料3-(4-羟基苯基)丙酸为原料生物合成根皮素奠定了基础，也展示了根皮苷工业化生产的潜力。
Phloretin is an important skin-lightening and depigmenting agent from the peel of apples. Although de novo production of phloretin has been realized in microbes using the natural pathway from plants, the efficiency of phloretin production is still not enough for industrial application. Here, we established an artificial pathway in the yeast to produce phloretin via assembling two genes of p-coumaroyl-CoA ligase (4CL) and chalcone synthase (CHS). CHS is a key enzyme which conventionally condenses a CoA-tethered starter with three molecules of malonyl-CoA to form the backbone of flavonoids. However, there was 33% of by-product generated via CHS by condensing two molecules of malonyl-CoA during the fermentation process. Hence, we introduced a more efficient CHS and improved the supply of malonyl-CoA through two pathways; the by-product ratio was decreased from 33% to 17% and the production of phloretin was improved from 48 to 83.2 mg L-1. Finally, a fed-batch fermentation process was optimized and the production of phloretin reached 619.5 mg L-1, which was 14-fold higher than that of the previous studies. Our work established a platform for the biosynthesis of phloretin from the low-cost raw material 3-(4-hydroxyphenyl) propanoic acid and also illustrated the potential for industrial scale bio-manufacturing of phloretin.