Enzymatic degradation of synthetic polymers This work investigated the enzymatic degradation of polyethylene terephthalate (PET) (ArticlesI and II) and polyvinyl alcohol (PVA) (Article III). Physical or chemical degradation of plastic polymers is often performed under extreme conditions like high temperatures or pressure. In comparison to that recycling of plastics with enzymes can be carried out at ambient temperatures and neutral pH. Enzymes themselves are non toxic environmentally friendly and have been used successfully in a variety of industrial processes. Enzymatic degradation of polyesters is well studied. Their heteroatomic backbone which is connecting monomers via ester bonds offers a target for an enzymatic attack. Especially PET one of the most common polyesters has been in the focus of research. The first enzyme capable of degrading the polymer was found in 2005. Since then researchers discovered several enzymes with similar functions and subjected them to enzyme engineering. Improving the enzymes substrate affinity activity and stability aims at making PET recycling more efficient. Article I provides an overview of limitations that enzymatic PET recycling is still facing and the research carried out to overcome them. More precisely enzyme−substrate interactions thermostability catalytic efficiency and inhibition caused by oligomeric degradation intermediates are summarized and discussed in detail. Article II further addresses one of the above mentioned limitations namely product inhibition ... plastic Enzym Abbau Polyethylenterephthalate Polyvinylalkohol Enzymatic Degradation Enzyme Engineering