# Combinatorial metabolic engineering of Saccharomyces cerevisiae for terminal alkene production

## TL;DR

Scientists engineered yeast to produce terminal alkenes, which are useful in industry, by improving fatty acid pathways and culturing conditions.

## Contribution

This is the first report of terminal alkene biosynthesis in Saccharomyces cerevisiae using combinatorial metabolic engineering.

## Key findings

- Combinatorial engineering strategies increased terminal alkene production titer by 67.4-fold.
- Optimizing precursor availability and cofactor engineering improved alkene titer significantly.
- Culturing condition optimization in bioreactors further increased the titer to 3.7 mg/L.

## Abstract

Biological production of terminal alkenes has garnered a significant interest due to their industrial applications such as lubricants, detergents and fuels. Here, we engineered the yeast Saccharomyces cerevisiae to produce terminal alkenes via a one-step fatty acid decarboxylation pathway and improved the alkene production using combinatorial engineering strategies. In brief, we first characterized eight fatty acid decarboxylases to enable and enhance alkene production. We then increased the production titer 7-fold by improving the availability of the precursor fatty acids. We additionally increased the titer about 5-fold through genetic cofactor engineering and gene expression tuning in rich medium. Lastly, we further improved the titer 1.8-fold to 3.7 mg/L by optimizing the culturing conditions in bioreactors. This study represents the first report of terminal alkene biosynthesis in S. cerevisiae, and the abovementioned combinatorial engineering approaches collectively increased the titer 67.4-fold. We envision that these approaches could provide insights into devising engineering strategies to improve the production of fatty acid-derived biochemicals in S. cerevisiae.