INRAE, Univ Montpellier, LBE, Narbonne, France.
Biotechnol Bioeng. 2021 Feb;118(2):601-611. doi: 10.1002/bit.27585. Epub 2020 Oct 15.
Oxygenic photogranules have been suggested as alternatives to activated sludge in wastewater treatment. Challenging for modeling photogranule-based processes is the heterogeneity of photogranule morphologies, resulting in different activities by photogranule type. The measurement of microscale-activities of filamentous photogranules is particularly difficult because of their labile interfaces. We present here an experimental and modeling approach to quantify phototrophic O production, heterotrophic O consumption, and O diffusion in filamentous photogranules. We used planar optodes for the acquisition of spatio-temporal oxygen distributions combined with two-dimensional mathematical modeling. Light penetration into the photogranule was the factor controlling photogranule activities. The spatial distribution of heterotrophs and phototrophs had less impact. The photosynthetic response of filaments to light was detectable within seconds, emphasizing the need to analyze dynamics of light exposure of individual photogranules in photobioreactors. Studying other recurring photogranule morphologies will eventually enable the description of photogranule-based processes as the interplay of interacting photogranule populations.
好氧光颗粒已被提议作为废水处理中活性污泥的替代品。对基于光颗粒的过程进行建模的挑战是光颗粒形态的异质性，导致不同类型的光颗粒具有不同的活性。由于丝状光颗粒的界面不稳定，因此很难测量其微尺度活性。我们在这里提出了一种实验和建模方法，用于量化丝状光颗粒中的光养产氧、异养耗氧和氧扩散。我们使用平面光探头获取时空氧分布，并结合二维数学模型进行分析。光穿透光颗粒是控制光颗粒活性的因素。异养生物和光养生物的空间分布影响较小。丝状生物对光的光合响应在几秒钟内即可检测到，这强调了在光生物反应器中分析单个光颗粒的光暴露动态的必要性。研究其他常见的光颗粒形态最终将能够描述基于光颗粒的过程，即相互作用的光颗粒群体的相互作用。
