State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
National Food Institute, Technical University of Denmark, Kemitorvet Building 201, DK2800 Kongens Lyngby, Denmark.
ACS Synth Biol. 2020 Mar 20;9(3):655-670. doi: 10.1021/acssynbio.9b00528. Epub 2020 Feb 28.
is used for industrial erythromycin production. To explore the physiological role of intracellular energy state in metabolic regulation by , we initially overexpressed the F part of the endogenous FF-ATPase in the high yielding erythromycin producing strain E3. The F-ATPase expression resulted in lower [ATP]/[ADP] ratios, which was accompanied by a strong increase in the production of a reddish pigment and a decreased erythromycin production. Subsequent transcriptional analysis revealed that the lower intracellular [ATP]/[ADP] ratios exerted a pleotropic regulation on the metabolism of . The lower [ATP]/[ADP] ratios induced physiological changes to restore the energy balance, mainly via pathways that tend to produce ATP or regenerate NADH. The F-ATPase overexpression strain exhibited a state of redox stress, which was correlated to an alteration of electron transport at the branch of the terminal oxidases, and channeled the enhanced glycolytic flux toward a reddish pigment in order to reduce NADH formation. The production of erythromycin was decreased, which is in accordance with the net ATP requirement and the excess NADH formed through this pathway. Partial growth inhibition by apramycin increased the intracellular [ATP]/[ADP] ratios and demonstrated a positive correlation between [ATP]/[ADP] ratios and erythromycin synthesis. Finally, overexpression of the entire FF-ATPase complex resulted in 28% enhanced erythromycin production and markedly reduced pigment synthesis in E3. The work illustrates a feasible strategy to optimize the distribution of fluxes in secondary metabolism.
被用于工业红霉素生产。为了探索细胞内能量状态在代谢调控中的生理作用，我们最初在高产红霉素生产菌株 E3 中过表达了内源性 FF-ATPase 的 F 部分。F-ATPase 的表达导致 [ATP]/[ADP] 比值降低，同时红霉素产量降低，产生大量红色色素。随后的转录分析表明，较低的细胞内 [ATP]/[ADP] 比值对 的代谢产生了多效调节作用。较低的 [ATP]/[ADP] 比值诱导了生理变化以恢复能量平衡，主要通过产生 ATP 或再生 NADH 的途径。F-ATPase 过表达菌株表现出氧化还原应激状态，这与末端氧化酶分支的电子传递改变有关，并将增强的糖酵解通量引导至红色色素以减少 NADH 的形成。红霉素的产量降低，这与净 ATP 需求以及通过该途径形成的过量 NADH 一致。通过安普霉素部分抑制生长增加了细胞内 [ATP]/[ADP] 比值，并表明 [ATP]/[ADP] 比值与红霉素合成之间存在正相关关系。最后，FF-ATPase 全酶复合物的过表达导致 E3 中红霉素产量提高了 28%，色素合成显著减少。这项工作说明了一种优化次级代谢通量分配的可行策略。
