Hydrogen-powered enzymatic valorization using multi-enzyme co-immobilization reactor with polypeptide-based cofactor swing-arm

Abstract

The chemical valorization of organic matter into high-energy products through reduction using oxidoreductase is a pivotal aspect from an energy perspective. Enzymatic valorization, utilizing the reduction potential of hydrogen contained in inexpensive resources such as coke oven gas (COG) and certain gasified plastics, enables environmentally friendly processes. Here, a strategy was proposed utilizing hydrogenase (H2ase), particularly soluble hydrogenase (SH), for selective utilization of H2 from mixtures without the separation processes. The co-immobilization of SH, elastin-like polypeptide (ELP)-based cofactor swing arm, and mannitol dehydrogenase (MDH) in a microreactor system were demonstrated for enzymatic valorization. The swing arm length and in-resin concentration were optimized to enhance electron mediation efficiency, leading to an improvement in productivity of about 3 mM/hr. Comparable productivity was observed in simulated COG and plastic waste-derived gas, which are promising results for the utilization of such low-purity H2 sources. Furthermore, the system demonstrates robustness and recyclability across maintaining productivity over 6 repeated batch reactions, highlighting its potential for industrial applications. Overall, our study provides valuable insights into the development of sustainable enzymatic microreactors for chemical valorization processes, contributing to greener and more efficient industrial practices.