As the accumulation of polymeric waste is an inevitable consequence of the produc-tion of polymers, scientists working on this field have the responsibility of developing tech-niques which make the processing and recycling of this kind of waste feasible. This task, how-ever, often proves to be challenging, mainly because the majority of the conventionally applied polymers cannot be depolymerized even under extreme conditions, such as strong alkali or acidic medium, high temperature or pressure. This is where biopolymers are coming into the picture: their majority can be depolymerized by using enzyme molecules, thus no harsh condi-tions are required anymore.

Consequently, the importance and significance of enzyme catalyzed polymer degra-dation increases continuously. Amongst many others, our research team has also been experi-menting with a number of enzyme molecules in the past, we have successfully carried out de-polymerization by using enzymes natively synthetized by the strains Bacillus megaterium, Burkholderia cepacia or Candida antarctica. While these experiments proved very promising, we had to cope with the difficulty that the enzyme is either cumbersome to produce on our own, or can be purchased from a vendor, yet the quality of the product is lacking even when its price is especially high.

The HunProtExc project, however, offered us the possibility to overcome these diffi-culties. The Polymer Physics Research Group of the Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences and the Department of Applied Biotechnol-ogy and Food Science, Budapest University of Technology and Economics are teamed up: now we are conducting our research together. The latter is responsible for the production of enzyme molecules by using gene recombinant E. coli strains, as well as for the preparation of inactive proteins by the implementation of PCR mutagenesis that makes the separate analysis of the steps of depolymerization possible.

The other participant of the cooperation, the Polymer Physics Research Group utilizes its infrastructure, knowledge and experience in a creation of amorphous poly(3-hydroxybutyrate) that could be prepared to have almost any arbitrary geometry: the most fre-quently as films, fibers and particles. As a part of our cooperation, the Polymer Physics Re-search Group is also responsible for the execution of the degradation experiments, as well as for the qualitative and quantitative analysis of the metabolites.

Beáta Vértessy, Károly Renner, Béla Pukánszky

Result_May 2020