Bacterial microcompartment architectures as biomaterials for conversion of gaseous substrates.

Bacterial microcompartments (BMCs) are protein shells encapsulating multiple enzymes of a metabolic pathway. Interpretations of early experiments on carboxysomes led to the narrative that transport of small gases (CO2, O2) across the shell membrane is restricted. Since then, this notion has been largely contradicted by studies of engineered shells, although these shell constructs lack important proteins present in the native BMCs, altering the synthetic shells' topology, surface and mechanical properties. We discuss here an updated model of gas permeability that informs the design of engineered shells for catalysis on gas substrates and outline how nonshell suprastructures of BMC shell proteins could be used in formulating sustainable biomaterials for hydrogen generation via methane pyrolysis and for other greenhouse gas mitigations.