CO2-based biodegradable plastics and their precursor production using photo-biocatalytic processes.

Biodegradable plastics are materials that can be decomposed by the action of microbes into water, CO, and biomass. They are attractive materials to solve the issue of serious environmental pollution due to plastic disposal. Some biodegradable plastics are produced entirely from petroleum-based precursors. The production of new biodegradable plastics and their precursors from CO and persistent organic or bio-based compounds using visible-light driven redox with biocatalytic processes is one of the effective resolutions for the environmental issues of plastic pollution and global warming. In this review article, recent research on the visible-light driven production of CO-based biodegradable plastics and their precursors using a system of light-driven redox and biocatalytic processes is introduced. As a first example, an overview of research into the production of biodegradable plastics, poly(hydroxybutyrate) (PHB) and their precursors such as acetate, shikimic acid, acetoin and so on from CO using a semiconductor photocatalyst-based photoredox system with a microbial cell as a biocatalytic process is provided. As a second example, an overview is provided of studies on the production of biodegradable plastic precursors, 3-hydroxybutyrate, L-malate and fumarate from CO and small organic molecules using an organic dye-based photoredox system with an electron donor, an electron mediator and enzyme-based biocatalytic processes.