Chem-bio interface design for rapid conversion of CO2 to bioplastics in an integrated system

Integrating catalytic CO2 reduction with bioconversion could substantially advance carbon capture and utilization and mitigate climate change. However, the state-of-the-arts are limited by inefficient electron and mass transfers, unfavorable metabolic kinetics, and inadequate molecular building blocks. We overcome these barriers with the systematic design of electrocatalysis, a chemical-biological (chem-bio) interface, and microorganisms to enable efficient electro-microbial conversion with C2 (EMC2) intermediates. The soluble C2 intermediates can facilitate rapid mass transfer, readily enter primary metabolism, have less toxicity, carry more energy and electrons, and serve as better molecular building blocks for many microorganisms. The multi-tier chem-bio interface design delivered the EMC2 system to achieve 6 and 8 times increase of microbial biomass productivity compared to C1 intermediate and hydrogen-driven routes, respectively. The multi-module synthetic biology design produced medium-chain-length polyhydroxyalkanoates (PHAs), biodegradable polymers, representing much higher productivity and molecular chain length than the platforms based on C1 intermediates, hydrogen, or electrons.