Understanding Benefits and Trade-offs in Coupling Cathodic and Anodic Processes in Continuous Electroenzymatic Reaction Cascades

• Applicants: Professor Dr. Nicolas Plumeré; Professor Dr. Volker Sieber
• Subject Area: Biological Process Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 536434374

This research proposal introduces an approach that integrates paired electrode processes with enzymatic reaction cascades, enabling redox-neutral processes to be carried out continuously in a flow system. The overarching objective is to investigate the advantages and trade-offs associated with coupling reductive and oxidative processes in diverse paired electrode configurations. The proposed model cascade involves the complete conversion of glucose into ethanol and carbon dioxide, employing six enzymes in a redox-neutral and pH-neutral system. Throughout the study, several critical research questions will be addressed. These include assessing the influence of electrode potential on coupled biocatalytic processes, studying the effect of reduction potentials on bioelectrocatalytic rate and selectivity, and developing strategies to address concentration gradients within the system. Additionally, efforts will be made to stabilize the system in cases where reactions are not ideally equilibrated. The stability and performance of selected enzymes under paired bioelectrocatalytic conditions will also be thoroughly examined. Furthermore, the investigation will explore the trade-offs and benefits of performing continuous oxidative and lytic reactions, as well as the advantages of conducting multiple oxidative reactions concurrently. The proposed research will be structured into various work packages, each targeting specific aspects of the paired electro-biocatalytic processes. The outcomes of this study hold significant potential for advancing the design of efficient bioelectrochemical cells based on coupled reactions. The findings will not only deepen our understanding of complex interactions within such systems but also offer valuable insights for optimizing enzyme cascades crucial for numerous industrial processes. Overall, this research aims to unlock the full potential of paired electro-biocatalytic processes, opening new avenues for sustainable and environmentally friendly technological applications.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2240: Bioelectrochemical and engineering fundamentals to establish electro-biotechnolgy for biosynthesis – Power to value-added products (eBiotech)
• Co-Investigators: Dr.-Ing. Ammar Al-Shameri, Ph.D.; Dr. Kannasoot Kanokkanchana