Jiao Tingting, Zhou Jingwen, Xu Sha
National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, Jiangsu, China.
School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.
Sheng Wu Gong Cheng Xue Bao. 2019 Jul 25;35(7):1256-1265. doi: 10.13345/j.cjb.180525.
Naringenin is a natural flavonoid compound with anti-inflammatory, anti-oxidation, anti-viral, anti-atherosclerosis and other pharmacological activities. It is also an important precursor of other flavonoid synthesis and with great value of application. At present, the production of flavonoids such as naringenin by microbial methods has a low yield due to imbalance of metabolic pathways, which greatly limits its industrial application. In this study, a naringenin-producing strain of Saccharomyces cerevisiae Y-01 was used in the research object. The expression levels of 4-coumaric acid: CoA ligase (4CL), chalcone synthase (CHS) and chalcone isomerase (CHI) were controlled by promoter and copy numbers to investigate the quantitative effect of key enzyme expression level on the accumulation level of target products. The results showed that the correlation between naringenin production and 4CL or CHI expression was not significant while there was a positive correlation with the expression level of CHS. Strain Y-04 with high yield of naringenin was obtained by regulating the expression level of chs gene, and the yield was increased by 4.1-folds compared with the original strain Y-01. This study indicated that CHS is a key regulatory target of naringenin synthesis. Rational regulation of CHS expression can significantly promote the accumulation of naringenin. The related results provide an important theoretical reference for the use of metabolic engineering to strengthen microbial synthesis of important flavonoids such as naringenin.
柚皮素是一种具有抗炎、抗氧化、抗病毒、抗动脉粥样硬化等药理活性的天然黄酮类化合物。它也是其他黄酮类化合物合成的重要前体，具有很高的应用价值。目前，由于代谢途径失衡，利用微生物方法生产柚皮素等黄酮类化合物的产量较低，这极大地限制了其工业应用。本研究以一株产柚皮素的酿酒酵母Y-01为研究对象。通过启动子和拷贝数控制4-香豆酸：辅酶A连接酶（4CL）、查尔酮合酶（CHS）和查尔酮异构酶（CHI）的表达水平，研究关键酶表达水平对目标产物积累水平的定量影响。结果表明，柚皮素产量与4CL或CHI表达之间的相关性不显著，而与CHS表达水平呈正相关。通过调控chs基因的表达水平获得了高产柚皮素的菌株Y-04，其产量比原始菌株Y-01提高了4.1倍。本研究表明，CHS是柚皮素合成的关键调控靶点。合理调控CHS表达可显著促进柚皮素的积累。相关结果为利用代谢工程强化微生物合成柚皮素等重要黄酮类化合物提供了重要的理论参考。
