Biofuel production with yeast – Boosting alkane production through enzyme engineering

Research Project, 2018 –

In recent years, the development of cell factories for shifting from a petroleum-based towards a bio-based industry has started to become reality. However, most of the advanced biofuels still face the
challenge of not being cost competitive with petroleum-based fuels. During the last years, several microorganisms have successfully been engineered towards the increased production of fatty acids
as precursors for high energy biofuels. Our research group is known for both engineering particular metabolic pathways and for increasing fatty acid precursor supply and final production of a variety of products. Although high titers for C16/C18 fatty acids were reached, the production of derived specialty products e.g. esters and alkanes remains relatively low. Medium- and long-chain alkanes, a specific type of advanced biofuels, are of high interest as kerosene and diesel substitutes because of their high similarity to fossil oil derived transportation fuels. So far, these high-energy drop-in biofuels have only been produced in very limited amounts through microbial production, mostly due to low enzymatic activity of the final enzymatic steps. In this project the focus is on the development of novel tools to optimize intracellular enzyme performance as important stepping stone to facilitate increased production. Besides rational approaches based on computational prediction of enzyme alterations, the engineering of enzymes involves in many cases the screening and analysis of thousands to millions of variants, commonly being a time consuming and cost intensive process. Novel, targeted methods for creating and screening these enzyme varieties in vivo will be developed within this project to unlock the full potential of in vivo enzyme engineering and further accelerate microbial strain development towards cost-competitive production of advanced biofuels.