Research break-through: Producing gasoline in yeast cell factories

There have been many attempts to modify this stubborn little enzyme. But none have succeeded, until now. With new findings from Chalmers the enzyme FAS has started to produce sustainable chemicals for biofuels.

​We are in great need of sustainable and clean alternatives to oil-derived products. One of the choices at hand is to produce chemicals and biofuels from sustainable biomass.

To do this, researchers in the group of Professor Jens Nielsen at the Department of Biology and Biological Engineering is hard at work trying to design yeast cell factories that can actually produce the chemicals we need in a sustainable way. The group now had a major break-through, as they developed a novel method of changing the enzyme FAS, fatty acid synthase, into producing new products.
– This enzyme normally synthesizes long chain fatty acids, but we have now modified it into synthesizing medium chain fatty acids and methyl ketones – chemicals that are components in currently used transportation fuels, Post-doc Zhiwei Zhu explains.
– In other words: We are able to produce gasoline and jet fuel alternatives by yeast cell factories, and this has never been done before.

The important enzyme was first elucidated by Nobel Prize winner Feodor Lynen, and many researchers have in recent years tried to modify it. But it seemed very hard, or close to impossible – until now.
– We did not expect this. Actually, it was thought by the scientific community that this rigid enzyme was not readily amenable to manipulation, says Zhiwei Zhu.

The findings are in fact a result of a lucky break. A few years ago, the researchers occasionally found a FAS which had two acyl carrier protein domains.
– We first tried to change this FAS by replacing one of its acyl carrier protein domains with a foreign enzyme to render it new activities, and surprisingly it worked. Then we implemented such modification in other fungal FASs and found this approach versatile.

The researchers are now focusing on using the modified enzyme to build yeast cell factories for production of chemicals and fuels. An invention patent has been filed, and the company Biopetrolia – a spin-off company to the Chalmers department – are closely involved, trying to further develop the technique to make it economically viable.

But as a researcher, Zhiwei Zhu also has a long-term goal of his own:
– I am also interested in deeply revealing the biochemical and structural basis of this novel modification in fungal FAS.

Link to the scientific article: Expanding the product portfolio of fungal type I fatty acid synthases

Text: Mia Malmstedt
In the photo: Zhiwei Zhu, Jens Nielsen and Biopetrolia CEO Anastasia Krivoruchko. Photo taken by Martina Butorac.

Published: Tue 28 Feb 2017. Modified: Fri 10 Mar 2017