A stepwise control strategy for enhancing glutathione (GSH) synthesis in yeast based on oxidative stress and energy metabolism was investigated. First, molasses and corn steep liquor were selected and fed as carbon source mixture at a flow rate of 1.5 g/L/h and 0.4 g/L/h, respectively, for increasing cell density in a 10 L fermenter. When the biomass reached 90 g/L, the KMnO4 sustained-release particles, composed of 1.5% KMnO4, 3% stearic acid, 2% polyethylene glycol and 3% agar powder, were prepared and added to the fermentation broth for maintaining the oxidative stress. The results showed that the maximum GSH accumulation of the group fed KMnO4 sustained-release particles was 39.0% higher than that of KMnO4-fed group. In addition to the improved average GSH productivity and average specific production rate, the activities of GSH peroxidase, γ-glutamylcysteine synthetase and GSH reductase, enzymes taking part in GSH metabolism, were also significantly enhanced by KMnO4 sustained-release particles feeding. Finally, 6 g/L sodium citrate fed as an energy adjuvant elevated the intracellular ATP level for further enhancing GSH production. Through the above stepwise strategy, the GSH accumulation reached 5.76 g/L, which was 2.84-fold higher than that of the control group. The stepwise control strategy based on oxidative stress and energy metabolism significantly improved GSH accumulation in yeast.

中文翻译：

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基于氧化应激和能量代谢的酿酒酵母中谷胱甘肽合成的逐步控制策略

研究了一种基于氧化应激和能量代谢的增强酵母中谷胱甘肽 (GSH) 合成的逐步控制策略。首先，选择糖蜜和玉米浆作为碳源混合物，分别以 1.5 g/L/h 和 0.4 g/L/h 的流速加入，以增加 10 L 发酵罐中的细胞密度。当生物质达到 90 g/L 时，制备由 1.5% KMnO4、3% 硬脂酸、2% 聚乙二醇和 3% 琼脂粉组成的 KMnO4 缓释颗粒并加入发酵液中以维持氧化应激. 结果表明，饲喂KMnO4缓释颗粒组的最大GSH积累量比饲喂KMnO4的组高39.0%。除了提高平均 GSH 生产率和平均比生产率外，GSH 过氧化物酶的活性、γ-谷氨酰半胱氨酸合成酶和谷胱甘肽还原酶这些参与谷胱甘肽代谢的酶也被高锰酸钾缓释颗粒饲料显着增强。最后，作为能量佐剂喂养的 6 g/L 柠檬酸钠提高了细胞内 ATP 水平，以进一步提高 GSH 的产生。通过上述逐步策略，GSH积累量达到5.76 g/L，是对照组的2.84倍。基于氧化应激和能量代谢的逐步控制策略显着改善了酵母中 GSH 的积累。通过上述逐步策略，GSH积累量达到5.76 g/L，是对照组的2.84倍。基于氧化应激和能量代谢的逐步控制策略显着改善了酵母中 GSH 的积累。通过上述逐步策略，GSH积累量达到5.76 g/L，是对照组的2.84倍。基于氧化应激和能量代谢的逐步控制策略显着改善了酵母中 GSH 的积累。