Identification and engineering of novel polyester hydrolases


Docking studies of a PET dimer with polyester hydrolases were used as a tool to predict the ligand orientation as well as the binding affinity between ligand and receptor. These data have been used as a guide for the design of more active and selective biocatalysts.

Polyester hydrolases for the functionalization of PET surfaces

Smooth surfaces created on PET fibres (right picture) by removal of surface PET oligomers (left picture) with a polyester hydrolase.



Biocatalysts active on synthetic polymers can be used to modify the properties of synthetic textiles and to produce new multi-functional materials for applications in the textile, electronic, and biomedical industry.

Biocatalytic recycling of plastic waste

The contamination of the environment by plastic wastes has become a global issue. Applying biotechnlogy to recycle this material by biocatalysis is a novel approach to mitigate this problem. The enzymatic hydrolysis of synthetic polymers such as polyethylene terephthalate (PET) and polyurethane (PU) by enzymes still remains a challange due to the high recalcitrance of their structures against biological attack. 

The enzymatic hydrolysis of post-consumer PET materials to their monomeric building blocks is investigated as an alternative to chemical recycling processes. A portfolio of polyester hydrolases is available for the development of biocatalytic recycling processes.

Bioreactors have been developed for the rapid hydrolysis of low-crystalline post consumer PET to the monomers terephthalic acid and ethylene glycol.

Carbohydrate Bioengineering


Cyclic oligosaccharides such as cyclodextrins with molecular recognition properties are becoming important tools as drug delivery systems, in biomaterial science and in nanobiotechnology. They find applications in the pharmaceutical, food, and chemical industry sectors. Other carbohydrate-derived products such as biosurfactants can be utilized as components of food, health, and cosmetic products.

This group of compounds can be produced from renewable biomass such as sugars and starches, offering environmental advantage over petrochemical-based products.

Cyclodextrin technology

Biosynthetic cyclic oligosaccharides such as cyclodextrins are becoming important tools in drug delivery and controlled release systems. Due to their molecular recognition properties, cyclodextrins can be used as building blocks for nanoscale structures with applications in biomaterial science and as functional units such as sensors in nanobiotechnology.

We have developed methods for the analysis of cyclodextrins and have identified a range of bacterial cyclic oligosaccharide-producing glucanotransferases. The ability of these enzymes to synthesize novel cyclodextrins, cyclic alpha-1,4-glucans composed of eight to more than several hundred glucopyranose units is investigated. This work involves the engineering of their cyclization activity and product specificity by site directed mutagenesis and directed evolution, the application of molecular imprinting techniques, and the development of enzymatic bioprocesses for their production.

letzte Änderung: 06.11.2019