Development of Biocatalysts – Enzyme Engineering

Nature provides a variety of biocatalysts (enzymes), all of which have the intrinsic ability to convert biogenic substrates. However, approaches for the conversion of biomass into basic and fine chemicals require biochemical parameters that differ significantly from those in the enzymes’ natural habitats. The enzymes must be compatible with each other, but also tolerate all intermediates that occur, high product concentrations and solvents.

In order to optimise them for this and for the corresponding biotransformations, we have to tailor many enzyme properties, such as (thermo)stability, specific activity, substrate specificity, cofactor specificity and inhibition. The focus is always on an application, but we also try to understand the molecular understanding of the catalysis processes in the enzyme through enzyme engineering. Successful examples from our work include stabilising enzymes to function at high temperatures, optimising general activity, changing cofactor specificity and using non-natural cofactors.

Crucial to the success of directed evolution is the quality of the libraries and the efficiency and accuracy of the screening procedures. We develop new mutagenesis and recombination strategies as well as chemical, enzymatic or physical high-throughput assays and selection methods. The assays are established in the classical 96-well format (medium to high throughput) on our robotic platform as well as for ultrahigh throughput applications on our microfluidic systems.