Microbial cell factories are used for the sustainable production of chemicals from renewable

lignocellulosic biomass. However, large-scale cost-effective application with traditionally used

microorganisms such as Escherichia coli or yeast is often hindered by limitations to consolidate the

microbial conversion with high-temperature and low-pH pretreatment processes inherent to the use

of recalcitrant lignocellulosic feedstocks. This necessitates the development of alternative hosts.

In this project, we will engineer the genetically amendable archaeon Sulfolobus acidocaldarius,

growing optimally at 75°C and pH 2-3, as a high-temperature microbial platform for the synthesis of

fatty acids, which are important platform molecules for the production of oleochemicals used in

applications ranging from biofuels to added-value chemicals. We will adopt a bottom-up synthetic

biology approach by engineering a thermophilic functionally reversed beta-oxidation pathway and

introducing this into S. acidocaldarius. A combinatorial pathway assembly approach will be used to

generate a multitude of strains, which will then be screened using a biosensor based on a native

acyl-CoA-responsive transcription regulator.

Besides exploring the use of S. acidocaldarius as a fatty acid production host, this project will deliver

generic tools and insights that are crucial to expand the reach of synthetic biology to non-evident

extremophilic hosts belonging to archaea, the "third domain of life".