Advances in biocatalytic membrane reactors for the production of non-commercially available pharmacologically active compounds from vegetal material

The use of plant derived products has a considerable impact on the environment in terms of energy saving and waste reduction. Developing low-cost enzymes remains a priority for both the Department of Energy's Office of the Biomass Program and for private industry. To achieve this goals, scientific advance in enzyme technologies, including enzyme production and/or re-use of enzyme, are required. Biocatalytic membrane reactors are extremely compatible with labile molecule, it is possible to work in mild conditions, the equipments need small space, are flexible and easy to scale-up (they are enabling technologies and well respond to the process intensification strategy); operating costs are low; energy used is low; products are of high quality; co-products are also of high quality. In addition it is possible to carry out enzymatic reaction in a continuous way controlling the fluid-dynamic conditions and to re-use the biocatalyst. The two compartments that biocatalytic membranes configuration has, permits to conduct the enzymatic reaction in multiphasic systems, a configuration particularly useful to isolate water insoluble products. In this work advanced nanostructured microporous membranes functionalized with biomolecules of plant origin were developed to demonstrate that biocatalyst properly immobilized in membranes permit the development of catalytic organized systems able to simultaneously carry out the bioconversion and the product separation, in a single unit. The biocatalyst used was vegetal -glucosidase, the substrate was oleuropein, a phenolic waste component coming from olive oil production process that can be also easily extracted from olive leaves. The hydrolysis of oleuropein gives high added value compounds pharmacologically active (aglycon, hydroxytyrosol and dialdehydes). The expensive heterogenized enzyme resulted stable and efficient in the oleuropein hydrolysis. Kinetic parameters of -glucosidase immobilized in the membrane reactor have been evaluated and compared with those of the ones of the free enzyme. Results evidenced that intrinsic kinetics of immobilized enzyme was not negatively affected compared to the free enzyme. This shows that lower catalytic activity of immobilized enzyme, commonly observed in the literature, is not an intrinsic technological drawback and that appropriate control of biohybrid microstructured systems, microenvironment conditions and transport