OBJECTIVE In this study, we aimed to maximize glutathione (GSH) production by a metabolically engineered Yarrowia lipolytica strain using a small-scale optimization approach. RESULTS A three levels four factorial Box-Behnken Design was used to assess the effect of pH, inulin extract, yeast extract and ammonium sulfate concentrations on cell growth and to generate a mathematical model which predict optimal conditions to maximize biomass production and thus GSH titer. The obtained results revealed that only yeast and inulin extract concentrations significantly affect biomass production. Based on the generated model, a medium composed of 10 g/L of yeast extract and 10 g/L of inulin extract from Jerusalem artichoke was used to conduct batch cultures in 2 L bioreactor. After 48 h of culture, the biomass and the glutathione titer increased by 55% (5.8 gDCW/L) and 61% (1011.4 mg/L), respectively, as compared to non-optimized conditions. CONCLUSION From the obtained results, it could be observed that the model established from small scale culture (i.e. 2 mL) is able to predict performance at larger scale (i.e. 2 L bioreactor, two orders of magnitude scale-up). Moreover, the results highlight the ability of the optimized process to ensure high titer of glutathione using a low-cost carbon source.

中文翻译：

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使用小规模优化方法通过代谢工程化解脂耶氏酵母菌株提高谷胱甘肽产量

目标在本研究中，我们旨在使用小规模优化方法最大限度地提高代谢工程化解脂耶氏酵母菌株的谷胱甘肽 (GSH) 产量。结果 三水平四因子 Box-Behnken 设计用于评估 pH 值、菊粉提取物、酵母提取物和硫酸铵浓度对细胞生长的影响，并生成预测最佳条件的数学模型，以最大限度地提高生物量产量，从而最大限度地提高 GSH 效价。获得的结果表明，只有酵母和菊粉提取物浓度显着影响生物质产量。基于生成的模型，使用由 10 g/L 酵母提取物和 10 g/L 菊芋菊粉提取物组成的培养基在 2 L 生物反应器中进行分批培养。培养 48 小时后，生物量和谷胱甘肽滴度增加了 55% (5. 8 gDCW/L) 和 61% (1011.4 mg/L)，与非优化条件相比。结论从获得的结果可以看出，从小规模培养（即2mL）建立的模型能够预测更大规模（即2L生物反应器，两个数量级的放大）的性能。此外，结果突出了优化过程使用低成本碳源确保高滴度谷胱甘肽的能力。