Magnetic amyloid-based biocatalyst for the hydrolysis of urea

ATHAYDE MONCORVO COLLADO A.; SOCIAS, S.B.; CHEHÍN R.; VERA-PINGITORE E.; CHAVES S.

Buenos Aires

Simposio; SAP 2019 - XIII Simposio Argentino de Polímeros; 2019

Ministerio de Ciencia, Tecnología e Innovación Productiva

The presence of urea in export wines and other beverages represents a recent problem since in the presence of ethanol it leads to the formation of ethyl carbamate, a carcinogenic agent according to the WHO. The regulations of the United States and the European Union establish an increasingly lower limit for their maximum levels in imported foods. Therefore, the objective was to obtain a catalyst for urea hydrolysis before bottling of beverages such as wine. It is important for this catalyst to be highly specific for urea degradation and not to alter other properties of the beverage. In addition, it is intended to be easily removable and leave no residue in the food. For this, soybean urease was immobilized in magnetic microparticles. In order to amplify the effective surface area of the particles and their capacity to act as support for the enzyme, chicken egg lysozyme fibers labeled with biotin were obtained. Secondly, fibers were incubated with magnetic particles marked with streptavidin. In addition to the effective surface increase, lysozyme fibers provided multiple active sites for the immobilization of the biocatalyst. Finally, soybean urease was immobilized in the fibers by CHICUP (Copper and Hydrogen peroxide Induced Cross-linking of Unmodified Proteins), giving rise to a magnetic biomicrocatalyst with remarkable urease activity, which is maintained even after 10 uses in laboratory conditions. Studies of activity and stability at acid pH and high concentrations of ethanol or tannins represent the next step for the characterization of this catalyst.