An engineered strain of the bacterium Escherichia coli can turn sugars such as glucose into a commercially important chemical.

Stephen Van Dien of Genomatica in San Diego, California, and his colleagues used computer models to design a biochemical pathway that converts common E. coli metabolites into 1,4-butanediol (BDO), which is used to make various plastics. For each step of the process, the researchers then inserted into the E. coli genes that normally encode enzymes in other bacterial species. They also tinkered with the bacterium's metabolism to drive energy and carbon molecules through this new pathway. The top-producing strain pumped out 18 grams of BDO per litre — a yield that would need to increase three- to fivefold to be commercially viable.

The bacteria could one day offer a low-cost way to make BDO from renewable products, rather than petroleum.

Nature Chem. Biol. doi:10.1038/nchembio.580 (2011)