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The target of agricultural biomass waste recovery from hydrolysis treatment is presented by comparing the performance of two different types of enzymatic polymeric membranes that were previously developed and characterized, based on a polysulfone derivative or monolithic polymers. Our aim was to achieve in one single step both enzymatic catalyzed hydrolysis of the xylan polysaccharide and the separation of the released products for the recovery of the short chain xylooligosaccharides. We present the behaviour of two different membrane modules operating in different procedure settings. The possible reuse of the membranes has also been evaluated. Xylooligosaccharides products have been characterized using Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry (MALDI-TOF-MS). The application of such enzymatic membranes enables the recovery of short chain xylooligosaccharides from biomass waste treatment, which has many potential applications in the food and pharmaceutical industries as well in the production of renewable energy.

We report on a new enzyme/support system to immobilize proteins such as enzymes through a covalent bond on polysulfone membranes. In the present case the enzyme endo-1,4-β-xylanase (E.C.3.2.1.8) is attached to polysulfone previously derivatized by introducing an acrylate group. Membranes are properly prepared from this polysulfone acrylate. Afterwards the enzyme is immobilized though the amino groups of side chains of the amino acids of the enzyme and the acrylate group of the derivatized polysulfone. Such immobilization of the enzyme is confirmed by microelemental analysis as well as by amino acid analysis by HPLC. Moreover, the enzymatic activity of the membranes was evaluated and compared with that corresponding to the free enzyme. Certain physical parameters (asymmetry, irregularity, pore size and surface roughness) of the corresponding enzymatic membranes were obtained from SEM and AFM image interpretation.

The aim of this work was the development and optimization of enzymatic monolithic membranes with high catalytic activity for the degradation of xylan into xylooligosaccharides. The chemometric tool design of experiments has been utilized here for the first time for the optimization of the enzymatic activity of the monolithic membranes based on their constituents. The effect of three process variables, including the amount of various monomer contents and the porogenic solvents ratio, has been studied on the enzymatic activity of the resulted membranes. The experimental design chosen was a central face centred with six central points in order to obtain an orthogonal model, with the precision of the results being independent of the range of values considered for each parameter. The software Modde(c) 6.0 from Umetrics(c) was used to build and analyze the results of the experimental design using partial least squares regression. The optimization of the suggested model provided the best membrane composition to achieve maximum enzymatic activity, which can be related to the amount of enzyme immobilized on the monolithic membrane. The predictive capacity of the model was evaluated performing additional experiments.