Miniaturization and automation have become increasingly popular in bioprocess development in recent years, enabling rapid high‐throughput screening and optimization of process conditions. In addition, advances in the bioprocessing industry have led to increasingly complex process designs, such as pH and temperature shifts, in microbial fed‐batch fermentations for optimal soluble protein expression in a range of hosts. However, in order to develop an accurate scale‐down model for bioprocess screening and optimization, small‐scale bioreactors must be able to accurately reproduce these complex process designs. Monitoring methods, such as fluorometric‐based pH sensors, provide elegant solutions for the miniaturization of bioreactors, however, previous research suggests that the intrinsic fluorescence of biomass alters the sigmoidal calibration curve of fluorometric pH sensors, leading to inaccurate pH control. In this article, we present results investigating the impact of biomass on the accuracy of a commercially available fluorometric pH sensor. Subsequently, we present our calibration methodology for more precise online measurement and provide recommendations for improved pH control in sophisticated fermentation processes.

中文翻译：

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过程适应性校准提高了复杂发酵过程中荧光 pH 传感器的精度

近年来，小型化和自动化在生物过程开发中变得越来越流行，能够快速高通量筛选和优化过程条件。此外，生物加工行业的进步导致微生物补料分批发酵中的工艺设计越来越复杂，例如 pH 和温度变化，以在一系列宿主中实现最佳可溶性蛋白质表达。然而，为了开发用于生物过程筛选和优化的精确缩小模型，小型生物反应器必须能够准确地重现这些复杂的过程设计。监测方法，如基于荧光的 pH 传感器，为生物反应器的小型化提供了优雅的解决方案，然而，先前的研究表明，生物质的固有荧光会改变荧光 pH 传感器的 S 形校准曲线，导致 pH 控制不准确。在本文中，我们展示了调查生物质对市售荧光 pH 传感器精度影响的结果。随后，我们介绍了用于更精确在线测量的校准方法，并为改进复杂发酵过程中的 pH 控制提供了建议。