Chemists at the University of California, Davis, have engineered blue-green algae, cyanobacteria, to grow chemical precursors for plastics – a first step to replacing fossil fuels as raw materials for the chemical industry.
"Most chemical feedstocks come from petroleum and natural gas, and we need other sources," said Shota Atsumi, assistant professor of chemistry at UC Davis and lead author on the study, published in the Proceedings of the National Academy of Sciences.
The challenge for the researchers was to get the cyanobacteria to make significant amounts of chemicals that can be readily converted to chemical feedstocks. With support from Japanese chemical manufacturer Asahi Kasei, the researchers identified enzymes from online databases that carried out the reactions they were looking for, and then introduced the DNA for these enzymes into the algae cells.
After three weeks growth, the cyanobacteria yielded 2.4 grammes of 2,3 butanediol per litre of growth medium – the highest productivity yet achieved for chemicals grown by cyanobacteria and with potential for commercial development, Atsumi said.
The US Department of Energy has set a goal of obtaining a quarter of industrial chemicals from biological processes by 2025.