Enzyme membrane reactors for production of oligosaccharides: A review on the interdependence between enzyme reaction and membrane separation

Certain types of oligosaccharides are especially interesting due to their high commercial value, however, the traditional oligosaccharide fabrication process is neither sustainable nor tailorable for obtainment of commercial standard oligosaccharide streams. The use of enzymatic membrane reactors (EMR) is proposed as a sustainable strategy to obtain oligosaccharides through a coupled bioreaction-separation process. In such process, glycosidic enzymes function as catalysts and membranes as selective barriers tailoring the molecular weight of products. Most of previous studies on oligosaccharides production by EMR have focused either on optimal operation of the enzyme reaction or the membrane filtration separately, but none of them have considered the implications of coupling both steps together. It is therefore the aim of this review to critically assess the available literature on the topic from a novel point of view: by paying special attention to the interactions between enzyme reaction-membrane filtration, which are critical for the performance of the overall process. Depending on the reaction conditions, the generated fouling directly affecting filtration performance varies. Such fouling depends on the membrane type and operation mode, which will in turn have an influence on the enzyme performance. The proposed review aims at providing a critical overview of the variables influencing performance and will provide tips for optimal configuration and operation of the coupled system.