Description:

Exploring Enzymatic Degradation Kinetics of Biopolymers using Surface Plasmon Resonance Spectroscopy

Xylan, an abundant polymer present in the cell walls of plants, has unique properties that make it ideal for various industrial applications in food, biofuel, pulp and paper industries. However, the extraction of xylan from natural sources is challenging because of its strong association with other plant cell wall polymers. To overcome this challenge, specialized enzymes, so-called xylanases, are used to selectively degrade xylan and thus facilitate dissolution and extraction. However, the surface activity of these enzymes at the solid-liquid interface is still poorly understood. Here, we investigate the activity of an endo-1,4-β-xylanase on xylan thin films using surface plasmon resonance spectroscopy. The influence of diffusion and changes in substrate morphology on enzyme surface kinetics is further investigated, including simulations to elucidate the degradation mechanisms of multilayer biopolymer films. Our results emphasize the significant influence of substrate properties, especially on the degradation efficiency of an endo-xylanase. Furthermore, we validate our results by applying the most advanced proposed kinetic model to the degradation of a thin film of polyhydroxybutyrate (PHB) treated with a PHB-depolymerase. This study emphasizes the importance of understanding heterogeneous enzymatic surface reactions and presents the derived models as valuable tools for identifying and quantifying factors that influence the reaction rates of different enzymes.

Bio: Dr. Jana Schaubeder is a postdoctoral researcher at the Institute of Bioproducts and Paper Technology at Graz University of Technology in Austria. During her Ph.D. she focused on the enzymatic degradation of biopolymers (mainly woody biomass) using surface plasmon resonance spectroscopy and received a grant for a general joint research project at the Exploratory Research Center on Life and Living Systems (National Institutes of Natural Sciences, Japan), where she was able to perform high-speed AFM measurements to visualize enzymatic degradation in situ. She received a Ph.D. in Chemical Engineering and a Master in Technical Chemistry from Graz University of Technology.