Xylan-cellulose thin film platform for assessing xylanase activity
Enzymatic degradation of plant polysaccharide networks is a complex process that involves disrupting an intimate assembly of cellulose and hemicelluloses in fibrous matrices. To mimic this assembly and to elucidate the efficiency of enzymatic degradation in a rapid way, models with physicochemical equivalence to natural systems are needed. Here, we employ xylan-coated cellulose thin films to monitor the hydrolyzing activity of an endo-1,4-β-xylanase. In situ surface plasmon resonance spectroscopy (SPRS) revealed a decrease in xylan areal mass ranging from 0.01 ± 0.02 to 0.52 ± 0.04 mg·m−2. The extent of digestion correlates to increasing xylanase concentration. In addition, ex situ determination of released monosaccharides revealed that incubation time was also a significant factor in degradation (P > 0.01). For both experiments, atomic force microscopy confirmed the removal of xylans from the cellulose thin films. We provide a new model platform that offers nanoscale sensitivity for investigating biopolymer interactions and their susceptibility to enzymatic hydrolysis.
a – Graz University of Technology, Institute of Bioproducts and Paper Technology (BPTI), Inffeldgasse 23, 8010 Graz, Austria b – Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden c – Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden d – Wallenberg Wood Science Center, Chalmers University of Technology, 412 96, Gothenburg, Sweden