A biopiezocatalyst harnessing mechanical energy to enhance bioplastic production from CO2 and organic carbon

The sustainable bioproduction of chemicals from CO2 remains far from reaching its full potential. The productivity of autotrophic bioprocesses could benefit from harnessing ubiquitous mechanical energy sources, which are inaccessible for energizing bioproduction systems to this day. In this work, we develop a hybrid system where the efficient piezocatalyst zinc oxide (ZnO) harnesses mechanical vibration to stimulate the growth of the chemolithoautotrophic bacterium Cupriavidus necator and its production of the bioplastic polyhydroxybutyrate (PHB) from CO2. Both ultrasonication and intense wave-like motion at least triple autotrophic PHB production with ZnO forming a cohesive aggregate with C. necator and transferring charges to its respiratory metabolism. The same ZnO-C.necator system doubles heterotrophic PHB synthesis from fructose, highlighting its extensive potential for multiple biosynthesis applications. The hybrid approach reported here provides a blueprint route for powering bioproduction from CO2 or other substrates with widespread mechanical energy such as industrial vibrations and natural waves. Mechanical energy is ubiquitous but inaccessible for microbial bioproduction. Here, the authors show that the piezocatalyst ZnO, upon mechanical stimulation, transfers charges to autotrophic Cupriavidus necator and enhances bioplastic synthesis.