State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
Biotechnol Lett. 2013 Dec;35(12):2137-45. doi: 10.1007/s10529-013-1317-0. Epub 2013 Sep 24.
Genetic manipulation was undertaken in order to understand the mechanism involved in the heterologous synthesis of lycopene in Escherichia coli. Knockout of the central carbon metabolic gene zwf (glucose-6-phosphate dehydrogenase) resulted in the enhancement of lycopene production (above 130 % relative to control). The amplification and overexpression of rate-limiting steps encoded by idi (isopentenyl diphosphate isomerase), dxs (1-deoxyxylulose-5-phosphate synthase) and ispDF (4-diphosphocytidyl-2C-methyl-D-erythritol synthase and 2C-methyl-D-erythritol 2,4-cyclodiphosphate synthase) genes improved lycopene synthesis from 0.89 to 5.39 mg g(-1) DCW. The combination of central metabolic genes knockout with the amplification of MEP pathway genes yielded best amounts of lycopene (6.85-7.55 mg g(-1) DCW). Transcript profiling revealed that idi and dxs were up-regulated in the zwf knock-out strain, providing a plausible explanation for the increase in lycopene yield observed in this strain. An increase in precursor availability might also have contributed to the improved lycopene production.
为了了解大肠杆菌中番茄红素异源合成所涉及的机制，进行了基因操作。敲除中央碳代谢基因 zwf（葡萄糖-6-磷酸脱氢酶）导致番茄红素产量提高（比对照提高 130%以上）。限速步骤编码基因 idi（异戊烯二磷酸异构酶）、dxs（1-脱氧木酮糖-5-磷酸合酶）和 ispDF（4-二磷酸胞苷-2C-甲基-D-赤藓醇合酶和 2C-甲基-D-赤藓醇 2,4-环二磷酸合酶）的扩增和过表达提高了番茄红素的合成量，从 0.89 到 5.39mg g(-1) DCW。中央代谢基因敲除与 MEP 途径基因的扩增相结合，产生了最佳量的番茄红素（6.85-7.55mg g(-1) DCW）。转录谱分析表明，在 zwf 敲除菌株中 idi 和 dxs 上调，为该菌株中观察到的番茄红素产量增加提供了合理的解释。前体可用性的增加也可能有助于提高番茄红素的产量。
