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

Abstract

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.