Scientists at the University of California, Davis have discovered how to create chemical precursors for fuel
and plastic using sunlight and cyanobacteria, otherwise known as blue-green algae.
"Most chemical feedstocks come from petroleum and natural gas, and we need other sources," said Shota Atsumi, assistant professor of chemistry at UC Davis.
By 2025, the U.S. Department of Energy hopes to obtain a quarter of industrial chemicals using biological processes.
The premise behind this discovery is photosynthesis — the forming of carbon-carbon bonds through carbon dioxide and the power of sunlight.
The use of cyanobacteria to create chemical precursors to fuel is advantageous because the blue-green algae does not deplete food sources as compared to using corn to make ethanol.
After identifying enzymes that displayed the desired reactions, chemists introduced the enzymes' DNA into the cyanobacteria cells. A three-step pathway was devised to allow the algae to turn carbon dioxide into 2,3 butanediol — commonly used to make paint, plastics, solvents and fuels.
The enzymes may perform differently depending on the organism, therefore it is difficult for scientists to predict how effective the three-step pathway will work prior to experimentation.
One difficulty facing scientists is how to get the blue-green algae
to make enough chemicals to be converted to chemical feedstocks. With the help of Japan's Asahi Kasei Corp., UC Davis is experimenting with adding new pathways into the cyanobacteria.
Atsumi reported that after three weeks, the cyanobacteria produced 2.4 grams of 2,3 butanediol per liter of growth medium. This is the highest amount achieved so far for chemicals produced using cyanobacteria and has potential for commercial applications.
of the study were published Jan. 7 in the Proceedings of the National Academy of Sciences.