Artifical biosynthesis breakthrough claimed

Researchers at the Lawrence Berkeley National Laboratory and the University of California at Berkeley are claiming a major advance in artificial biosynthesis after developing a system which can capture carbon dioxide and, using sunlight, convert it into biodegradable polymers, pharmaceutical ingredients or liquid fuels. The system combines the use of semiconductor nanowires and bacteria in a hybrid network, as the team describes in the journal Nano Letters.

The system consists of an ‘artificial forest’ of nanowires made out of silicon and titanium oxides, which lead researcher Peidong Yang says are analoguous to the chloroplasts in green plants — the chlorophyll-containing cells where photosynthesis takes place. When sunlight hits these structures, electrons are freed from the titanium and silicon atoms, which absorb different light wavelengths, and are passed on to Sporomusa ovata bacteria which are nestled within the nanowires “like Easter eggs buried in tall grass,” as co-author Michelle Yang describes it; these bacteria then reduce the carbon dioxide, transforming the usually very stable carbon atom into a more reactive form. Meanwhile, the positively-charged ‘holes’ left by the electrons force water molecules in the air to split apart, generating reactive oxygen that reacts with the reduced CO₂ to form acetate, a useful building-block for other organic molecules.