Detailed studies of microbial growth in bioelectrochemical systems (BESs) are required for their suitable design and operation. Here, we report the use of optical coherence tomography (OCT) as a tool for in situ and noninvasive quantification of biofilm growth on electrodes (bioanodes). An experimental platform is designed and described in which transparent electrodes are used to allow real‐time, 3D biofilm imaging. The accuracy and precision of the developed method is assessed by relating the OCT results to well‐established standards for biofilm quantification (chemical oxygen demand (COD) and total N content) and show high correspondence to these standards. Biofilm thickness observed by OCT ranged between 3 and 90 μm for experimental durations ranging from 1 to 24 days. This translated to growth yields between 38 and 42 mg g ⁻¹ at an anode potential of −0.35 V versus Ag/AgCl. Time‐lapse observations of an experimental run performed in duplicate show high reproducibility in obtained microbial growth yield by the developed method. As such, we identify OCT as a powerful tool for conducting in‐depth characterizations of microbial growth dynamics in BESs. Additionally, the presented platform allows concomitant application of this method with various optical and electrochemical techniques.

中文翻译：

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使用光学相干层析成像技术在生物电化学系统中进行原位生物膜定量

为了进行适当的设计和操作，需要对生物电化学系统（BES）中的微生物生长进行详细研究。在这里，我们报告使用光学相干断层扫描（OCT）作为原位和非侵入性定量电极（生物阳极）上生物膜生长的工具。设计并描述了一个实验平台，其中使用透明电极进行实时3D生物膜成像。通过将OCT结果与成熟的生物膜定量标准（化学需氧量（COD）和总氮含量）相关联，可以评估所开发方法的准确性和精密度，并显示出与这些标准的高度对应性。通过OCT观察到的生物膜厚度范围为3至90μm，实验持续时间为1至24天。这转化为38至42 mg的生长产量g ^-1在相对于Ag / AgCl的-0.35 V的阳极电势下。一式两份进行的实验运行的延时观察显示，通过开发的方法获得的微生物生长产量具有很高的重现性。因此，我们认为OCT是进行BES中微生物生长动力学深入表征的强大工具。另外，提出的平台允许该方法与各种光学和电化学技术相伴随地应用。