Using yeast to produce fatty acids is a sustainable alternative to conventional production. However, yeast cells must be genetically engineered to be a cost-efficient alternative. In a newly published study researchers at Chalmers have rewired the metabolism of baker’s yeast resulting in the best fatty acid producing yeast cells ever reported.
Yeast cells, often baker’s yeast (Saccharomyces cerevisiae), can be used industrially as so-called cell factories for sustainable production of biofuels, biochemicals and food ingredients. To provide cell factories that ensure cost-efficient sustainable production researchers are looking for new ways to engineer yeast strains for high yield production.
Wanted to decouple fatty acid production from growth
In a newly published study Jens Nielsen, Professor of Systems Biology at Chalmers, and his research group rewired the energy metabolism in yeast cells to achieve a higher yield of fatty acid production. This will enable sustainable production of these compounds.
“Normally fatty acids are produced as they are needed for cellular growth, but we were wondering if we could decouple fatty acid production from cellular growth. This is very hard as this coupling has been established through millions of years of evolution”, says Jens Nielsen, continuing:
“When Tao Yu, the first author of the paper, showed me his idea for how to completely rewrite metabolism with the objective to decouple fatty acid production and growth, I was somewhat sceptical. But Tao worked on, and we now have the best fatty acid producing yeast cells ever reported.”
Drastic changes to the central metabolism
In the study the researchers created a completely new energy generation system in the cells that can better support the production of fatty acids. This involved more than 20 genetic changes resulting in a completely different operation of the cellular metabolism. Yeast has evolved over millions of years to have a certain type of metabolism that we know very well − to make ethanol (beer and wine) − and many people have tried to change this part, normally called the central metabolism, without much success.
“However, if we really perform drastic changes, as we did here, then it is possible to change the central metabolism completely. Bacterial cells tend to have a more plastic metabolism, probably because they have evolved to adapt quicker to changes in environment. Yeast, on the other hand, is of the same cell type as plants, animals, and humans, and they generally have a less plastic metabolism. But still we could go to the drawing board and lay out a strategy for very dramatic changes,” says Jens Nielsen.
How can this approach be used for future research and applications?
“With this research we have learned a lot of new things about metabolism that can be used for also other engineering strategies in the future where we want to apply yeast for sustainable production of other fuels, chemicals, and foods,” says Jens Nielsen.
Read the scientific article in Nature Metabolism: Metabolic reconfiguration enables synthetic reductive metabolism in yeast
Contact
- Full Professor, Systems Biology, Life Sciences