Electroactive biofilms can provide us with a sustainable way to generate electrical current. A great biological process to recover resources through electrochemical means. Wetsus and Wageningen researchers discovered the optimal biofilm thickness to squeeze every last available electron from these bacteria.
The key to this success was the development of a technique to measure the biofilm thickness in real-time. Measuring this variable as a function of time, and relating it to the current density, yielded the scientists insight into this as-of-yet unknown optimal thickness of the biofilms on electrical anodes.
The size of the bacterial layer is one of the most critical measures to perfect, as it is the interface between the substrate and the electrode itself. In theory, a thicker biofilm would be better at generating electricity, but it would have limited access to the substrate. This has to do with the balancing act between the substrate (electron donor) and electrode (electron acceptor).
Pereira, João, Siqi Pang, Casper Borsje, Tom Sleutels, Bert Hamelers, and Annemiek ter Heijne. 2022. “Real-Time Monitoring of Biofilm Thickness Allows for Determination of Acetate Limitations in Bio-Anodes.” Bioresource Technology Reports 18 (June): 101028. https://doi.org/10.1016/j.biteb.2022.101028.