Fatty Acid Overproduction in a Genetically Engineered Puryvate Decarboxylase-Negative Strain of Saccharomyces Cerevisiae

The energy supply of modern society is majorly based on fossil fuels. Yet petroleum is a declining resource and easily accessible reserves are assumed to be depleted in a foreseeable future, which is why current petroleum based fuels will have to switch into ones established from renewable resources. One alternative is to develop efficient cell factories, which can directly convert plant-based material into fuels, for example alkanes or fatty acid ethyl esters. To obtain such high-energy fuel compounds, the production host needs to synthesize high amounts of fatty acids. During fermentation processes, however, the formation of unwanted byproducts will reduce the yield of the sought fuel product.

The overall objective of this project is to obtain a fatty acid overproducing strain of Saccharomyces cerevisiae, which through several chromosomal gene deletions will have lost function to produce ethanol, storage lipids as well as its capability of catabolizing fatty acids. Such a yeast strain could be valuable as a platform strain for the production of energy dense biofuels. Heterologous pathways will be installed to redirect carbon flux towards cytosolic acetyl-CoA, the precursor for synthesis of fatty acids. Furthermore, enzymes involved in producing fatty acids from acetyl-CoA will be overexpressed in order to create a “pull”, which potentially can increase flux through the heterologous pathways. Integrative analysis of multi-omics data will be performed to characterize the established strains, and the obtained results will in combination with predictive computer modeling act as tools to identify important metabolic flux controlling factors. Such insights could potentially be used for optimization of the created system or implementation of other biosynthetic pathways.