Scientists make plastic from sunshine

Scientists from the University of California at Berkeley and the Lawrence Berkeley National Laboratory have combined two common bacteria to mimic photosynthesis and make industrial chemicals from sunlight and carbon dioxide. The work presents yet another challenge to the petroleum industry, on which manufacturing now largely relies for constituent chemicals.

The process gathers sunlight in a mesh of nanowires fashioned from silicon and titanium oxide, each of which absorbs a different portion of the sun’s light spectrum. Light absorbed by the silicon is used to make carbon dioxide; light taken up by titanium is used to separate water molecules into hydrogen and oxygen.

The two bacteria live on the wire mesh. One, called sporomusa ovata, is aces at reducing carbon dioxide to acetate, a building block of plastics, paints and similar products. The second, a harmless variety of E. coli, is skilled at turning acetate into other chemicals that underlie commonly manufactured substances. So far, the researchers have used the technique to make butanol, a plastic called PHB, and the foundation chemical for a common anti-malaria drug.

TRENDPOST: This new process uses solar energy about as poorly as a natural leaf, which is less than half of 1 percent energy-efficient. The research team thinks that 10 percent efficiency is needed to make a commercial product. Their quest is likely to be helped by the research attention and dollars being showered on artificial photosynthesis, which has been shown in tests to be able to synthesize engine fuel, make chemicals and sequester waste carbon.