Background- Thermophilic organisms are composed of both bacterial and archaeal species. The enzymes isolated from these species and from other extreme habitats are more robust to temperature, organic solvents and proteolysis. They often have unique substrate specificities and originate from novel metabolic pathways. Thermophiles as well as their stable enzymes (‘thermozymes’) are receiving increased attention for biotechnological applications.
The proposed project will establish thermophilic in vitro enzyme cascades as well as two new chassis, the thermophilic bacterium Thermus thermophilus (Tth, 65-75°C, pH 7.0) and the thermoacidophilic archaeon Sulfolobus acidocaldarius (Saci, 75-80°C, pH 2-4), as new thermophilic, bacterial and archaeal platforms for the production of novel high added-value products, i.e. ‘extremolytes’. Extremolytes are small molecular compatible solutes found naturally in the cells of thermophilic species that accumulate in the cell in response to multiple environmental stresses and stabilize cellular components (including proteins, membranes). Extremolytes offer an amazing so far unexploited potential for industrial applications including food, health, consumer care and cosmetics. However, their production in common mesophilic organisms (i.e. yeast, E. coli) is currently hampered by the hyperthermophilic origin of the respective metabolic pathways requiring a thermophilic cell factory.