REDOX METALLOENZYMES AND THEIR APPLICATIONS

Biohydrogen

At the dawn of the 21st century a global environmental and energy crisis threatens the sustainable lifestyle of mankind. As long as there is plenty of fossil energy carrier available, every aspect of our life is supported by the use of these resources. It is, however, an undeniable fact, supported by several lines of independent evidence that the uncontrolled consumption of fossil energy damages the environment to a degree that threatens the survival of the human race and many other plant and animal species. Hydrogen is the simplest molecule and is considered to become the renewable energy carrier of the future, which is capable of replacing the carbon-based fossil fuels in a sustainable manner. If hydrogen is produced at an industrial scale ultimately from solar energy, it can alleviate the environmental disasters foreseen due to global warming and eliminate political tensions among various geographical regions.

Hydrogen, just like electricity, is an energy carrier that cannot be exploited using conventional mining technologies. Currently it is produced from fossil energy sources, mainly from natural gas. This approach does not solve any of the environmental and geopolitical concerns. Hydrogen could be generated from renewable primary energy sources with an acceptable efficacy; these biotechnological methods evolve and improve rapidly and offer promise for a future hydrogen-based economy.

The key enzyme of hydrogen production and utilization is hydrogenase, a protein containing redox active metallocentre(s). The main aim of our research program is to understand the molecular details of this enzyme function, the regulation of its biosynthesis and, in general, to study the metal-protein interaction in redox metalloenzymes. The results are not ready yet for large-scale practical application, but we could already create modified bacteria, which display outstanding hydrogen productivity. Most of these miniature hydrogen factories derive from an easy-to-handle phototrophic bacterium.

Bioremediation

Many different microbial strains contain enzymes and metabolic pathways that can be exploited to degrade hazardous, poisonous chemicals, e.g. the recalcitrant chlorinated hydrocarbons. The bioremediation methods identify the best microorganisms for the elimination of the target compound and improve its performance by traditional training or via molecular biological tools. We have developed strains that degrade hydrocarbons, their halogenated derivatives, lipids, chemicals in the waste streams of the pharmaceutical, pesticide, and food processing industries. These studies also took us to the field of biosurfactants, i.e. biodegradable detergents and to the production of industrial enzymes.

An industrial fermentation facility, operated by the spin-off Corax-Bioner Inc. produces about 20,000 m3/year of microbial cultures for bioremediation and organic farming. Our team provides the scientific background for the product development of the company on the basis of a long-term collaboration agreement.