A genetically programable strain of yeast powered by light-harvesting nanoparticles can make high-value chemicals from simple and renewable carbon sources, according to a new report. The semiconductor-microbe hybrid enables notably high carbon conversion by overcoming existing limitations in bioinorganic systems. Its structure offers a new foundation for the future design of biohybrid microbes capable of efficient, adaptable biomanufacturing of a greater array of molecules. Microorganisms such as bacteria or fungi are commonly used in industrial biomanufacturing based largely on their rapid proliferation and ability to convert carbon sources such as sugar into a variety of high-value organic molecules. By genetically tweaking their metabolic processes, researchers transform such organism's into manufacturing workhorses. Biohybrid systems - which combine the light-harvesting abilities of inorganic systems with the biosynthetic capabilities of living cells - offer a promising method for producing high-value chemicals. Existing microbial hybrid systems, however, are based largely on autotrophic bacteria, which generally produce a limited range of simple chemical products when compared to the more flexible heterotrophic microbes. Heterotrophs require organic sources of carbon-based "fuel," like sugar, to regenerate cellular NADPH, a coenzyme that drives metabolic processes. This requirement has been a persistent challenge towards developing efficient "cell factories." Junling Guo and colleagues present a highly modular bioinorganic hybrid platform based on heterotrophic Saccharomyces cerevisiae - baker's yeast - which is widely used in biomanufacturing. In this study, Guo et al. coated a genetically modified strain of this yeast in inorganic, nanoparticle semiconductors. The bioinorganic yeast system harvests energy from light absorbed by constituent light-sensitive nanoparticles. This energy is transferred to the living cell and used to regenerate the NADPH required for biosynthetic reactions.
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Science