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Synthetic biology used to engineer new route to biochemicals

June 25, 2015
University of California - Davis
Chemists create a new pathway that allows E. coli bacteria to feed on sugar and acetate to make isobutyl coA, a raw material for fuels and chemicals.

Engineered bacteria use both glucose and acetate, instead of just glucose, as raw material to make isobutyl acetate, which can be used in chemical manufacturing and as fuel.
Credit: Courtesy of Shota Atsumi/UC Davis

Living cells can make a vast range of products for us, but they don't always do it in the most straightforward or efficient way. Shota Atsumi, a chemistry professor at UC Davis, aims to address that through "synthetic biology:" designing and building new biochemical pathways within living cells, based on existing pathways from other living things.

In a new paper published by Nature Communications June 25th, Atsumi and colleagues Yohei Toshiro and Shuchi Desai describe building a new pathway that lets the bacterium, E. coli, feed on both sugar (glucose) and acetate, a common waste material from biomass, to make isobutyl acetate. This product can be used as the basis for flavoring agents, solvents and fuels.

The original pathway starts with glucose, which is converted into both isobutanol (via a pyruvate intermediate) and into acetyl-coenzyme A, a common building block in biochemistry used for making biochemicals such as proteins, fats and alcohols, among other things. The theoretical maximum carbon yield from this pathway is 67 percent, which is lower than chemists would like to see.

Atsumi's team engineered E. coli so that they could scavenge acetate to make acetyl-CoA while using glucose to make isobutanol. The new pathway raises the theoretical maximum carbon yield of isobutyl acetate to 75 percent.

The process might be further improved by using an acetate-assimilation pathway from other soil bacteria that are better at living off acetate than E. coli, the authors note. Because acetyl-CoA is such an important material for making other biological molecules, direct acetate assimilation could have wide application in biotechnology.

The work was supported by a Hellman Fellowship.

Story Source:

Materials provided by University of California - Davis. Original written by Andy Fell. Note: Content may be edited for style and length.

Journal Reference:

  1. Yohei Tashiro, Shuchi H. Desai, Shota Atsumi. Two-dimensional isobutyl acetate production pathways to improve carbon yield. Nature Communications, 2015; 6: 7488 DOI: 10.1038/ncomms8488

Cite This Page:

University of California - Davis. "Synthetic biology used to engineer new route to biochemicals." ScienceDaily. ScienceDaily, 25 June 2015. <>.
University of California - Davis. (2015, June 25). Synthetic biology used to engineer new route to biochemicals. ScienceDaily. Retrieved May 26, 2017 from
University of California - Davis. "Synthetic biology used to engineer new route to biochemicals." ScienceDaily. (accessed May 26, 2017).