2019. június
Dr. Somogyi Viola és Dr Meiczinger Mónika két előadás keretében bemutatta a 3rd ANQUE-ICCE International Congress of Chemical Engineering konferencián a projekt során elért eredményeket.
Immobilization of Laccase Inside a Microfiltration Membrane for Removal of Diclofenac
Szerzők: Varga Béla, Lana Wolmarans, Meiczinger Mónika és Somogyi Viola
Abstract:
Biocatalytic processes in different fields of industry are well recognized nowadays. Similarly, integrated membrane separation has become common, since it can decrease the complexity of the downstream processes and also increase the viability of certain treatment methods. The removal of different micropollutants from wastewater by conventional biological wastewater treatment is not efficient, therefore polishing processes are required. Elimination of these contaminants from the effluent can be achieved by membrane separation processes such as anofiltration or reverse osmosis, although the integration of those is complicated. Similarly, the different organic micropollutants can be transformed using oxidoreductase enzymes as biocatalysts, for example laccase. However, the separation of the reaction products is just as important as the conversion. In this study a method is described that was developed for the immobilization of laccase inside the pores of a microfiltration membrane by producing cross-linked enzyme aggregates (CLEAs). Using glutaraldehyde as a cross-linker, intermolecular bonds were produced between the laccase molecules. These connections produce a network of enzymes inside the porous structure of the membrane, which allows the retention of the catalysts and the separation of reaction products. First, the catalytic membrane was tested in an enzymatic membrane reactor by a well-known substrate of laccase, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), then the conversion of a broadly prescribed pharmaceutical, diclofenac was investigated. The membranes were successfully used for several cycles without major decrease of enzyme activity and separation of certain diclofenac products was achieved.
Laccase Immobilization by Different Techniques in Biocatalytic Membrane Reactor
Szerzők: Meiczinger Mónika, Varga Béla, Nagy Endre, Somogyi Viola
Abstract:
The problem of micropollutants appearing in our wastewater and subsequently in our water resources, thus risking the contamination of drinking water is as real as climate change. These pollutants originating from agricultural, pharmaceutical industry as well as households have proven harmful effects on living organisms despite their concentration being between ng/L- µg/L. The use of micro- and ultrafiltration membranes in wastewater treatment is a well- known and accepted method but it is not suitable for filtering micropollutants. Certain enzymes, such as laccase from Trametes versicolor, can remove these impurities via biochemical reactions, but their activity is very sensible to environmental conditions. Immobilizing enzymes to membranes may be a possible solution for removing these contaminants without having to use nanofiltration and may improve their stability and longtime activity. Other options would be to immobilize the enzymes to biodegradable nanoparticles or the combination of these methods. In this study the efficiency of the different immobilization techniques and conditions were examined. On one hand, β -cyclodextrin was used to prepare a biocatalyst nanocomposite which was immobilized later to the support layer of an asymmetric flat - sheet ultrafiltration membrane by applying pressure. On the other hand, free enzyme in itself was also immobilized to the same type of membrane. The change of enzyme concentration was measured in each case with Bradford method. The effect of different pressure values on the process was also investigated.
