In this work, a kinetics-integrated CFD model based on coupling computational fluid dynamics (CFD) and biokinetic was developed to guide the industrial scale-up for fermentation of docosahexaenoic acid (DHA). Two-substrate biokinetic equations for a 5 L bioreactor with oxygen and nitrogen source as limiting substrates were established, which were further coupled with CFD to simulate the biomass growth and lipid accumulation as well as flow field environment in the fermentation process. The coupled CFD-biokinetic model can accurately reflect the changes of each relevant variable in the 50 L bioreactor under different operating conditions. The optimal working conditions of a 35 m³ bioreactor were predicted by this model and have secured the one-step scale-up of DHA fermentation, resulting in a biomass, lipid concentration, and DHA content in lipids of 99.2 g/L, 55.7 g/L, and 52.5%, respectively. This study thus provides an effective strategy for rapid industrial scale-up of DHA production.

中文翻译：

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使用 Schizochytrium sp. 开发用于工业放大 DHA 发酵的动力学集成 CFD 模型。

在这项工作中，开发了一种基于耦合计算流体动力学 (CFD) 和生物动力学的动力学集成 CFD 模型，以指导二十二碳六烯酸 (DHA) 发酵的工业放大。建立了以氧和氮源为限制底物的5 L生物反应器的双底物生物动力学方程，并进一步与CFD耦合模拟了发酵过程中的生物质生长和脂质积累以及流场环境。耦合CFD-生物动力学模型可以准确反映50 L生物反应器在不同运行条件下各相关变量的变化。^{35 m 3}的最佳工作条件生物反应器由该模型预测，并确保了DHA发酵的一步放大，导致生物量、脂质浓度和脂质中的DHA含量分别为99.2 g/L、55.7 g/L和52.5%。因此，这项研究为 DHA 生产的快速工业规模化提供了有效的策略。