Nanoscale tuning of enzyme localization for enhanced reactor performance in a novel magnetic-responsive biocatalytic membrane reactor

The synergistic magnetic interaction between biofunctionalized magnetic nanoparticles and a hybrid membrane is exploited to develop a nano-inspired, magnetic-responsive enzyme membrane (micro) reactor. The novelty of the process lies in the use of superparamagnetic nanoparticles both as enzyme carrier to form bionanocomposites and as nanofiller to form organic-inorganic (O/I) hybrid membrane to render both reversibly magnetizable. This reversible magnetic force facilitates dispersion of the enzymatically active magnetic nanoparticles (bionanocomposites) over the membrane surface, allows retention of the enzyme by a large pore, i.e., high-flux membrane and renders enzyme recovery after use is very easy. The feasibility and versatility of the concept is demonstrated through 2 case studies, i.e., a pectin/polygalacturonase and an arabinoxylan/xylanase system, for membrane fouling prevention through in-situ enzymatic membrane cleaning. This robust multidisciplinary approach resulted in a 75% reduction in filtration resistance, thus realizing significant energy savings and high reactor productivity. The advantages of the novel approach include: (i) absence of need for neither functionalized nor retentive membrane surfaces, (ii) no leakage of nanosized, high surface area immobilized enzymes through microporous membranes, (iii) full recovery and re-usability of the enzymes, (iv) possibility to apply enzyme cocktails to achieve optimal conversions and (v) use of the membrane beyond the enzyme life cycle.