Enhancing Carbon Conversion Efficiency and Product Yield Through Systematic Biocatalyst Design for Microbial Electrosynthesis

The growing issue of greenhouse gases, particularly carbon dioxide, has heightened the urgency to address the climate crisis. This has spurred the creation of innovative carbon capture and utilization (CCU) methods, with microbial electrosynthesis (MES) emerging as a promising approach. MES harnesses the power of microbial biocatalysts to convert CO2 into valuable chemical compounds (CCCs) through an electrochemical process.

In this study, researchers focused on developing and maintaining diverse mixed microbial communities of electroactive bacteria (EAB) sourced from wastewater treatment sludge to act as biocatalysts in MES.

To evaluate the effectiveness of these biocatalysts, the study examined their performance under various operational conditions within bioelectrochemical systems (BES) reactors. The results revealed that MES systems with biocatalysts incubated at controlled temperatures outperformed those developed at ambient temperatures in terms of CCCs yield. Moreover, maintaining strict anaerobic conditions further enhanced the MES efficiency compared to aerobic conditions.

The researchers found that when a potential of -1000 mV versus Ag/AgCl was applied, the CO2 conversion reached an impressive 88.11%, significantly surpassing the performance at a lower potential of -600 mV. These findings emphasize the significance of systematically designing and maintaining robust, stable biocatalysts, as well as adhering to strict anaerobic conditions, to achieve efficient MES performance.

This research demonstrates the potential of the proposed approach for large-scale industrial CCU applications, offering a promising solution to mitigate the adverse effects of greenhouse gases.