Photosynthetic conversion of CO2 to acetic acid by an inorganic-biological hybrid system

Abstract

Recent work by Sakimoto et al. has adopted such an approach by inducing the bacterium Moorella thermoacetica (M. thermoacetica) to precipitate and decorate itself with cadmium sulfide nanoparticles. This cyborgian bacteria, M. thermoacetica-CdS, when illuminated by sunlight, is able to use the photogenerated electrons to reduce CO2 into acetic acid with exceedingly high quantum efficiencies. While many synthetic CO2 reducing catalysts can achieve high efficiencies in converting to C1 products (such as methane, carbon monoxide, formic acid, etc.), this C2 product holds great promise as a non-volatile, non-toxic intermediate that could serve as a biofeedstock commodity chemical, ready to be upgraded to a variety of biofuels, biopolymers, and pharmaceutical precursors. This first generation system opens up a new parameter space to investigate such bio-inorganic hybrid systems: biosynthesizing smaller band gap semiconductors to increase light absorption and energy conversion efficiency, genetic engineering to produce more complicated organic molecules, and more.