Potential application of acid urease immobilization on biological nanotubes

CHEHÍN ROSANA

Buenos Aires

Jornada; Giornate del CUIA in Argentina; 2014

Embajada de Italia en Argentina

Ethyl carbamate (urethane) is a naturally occurring component in all fermented foods and beverages, being spontaneously produced by the reaction between urea and ethanol. When administrated in high doses in animal tests, urethane has revealed potential carcinogenic activity. Thus, there is a great deal of concern to reduce urethane levels in food products, and for instance, in wines a safe level of 15 μg/L has been so far recommended. The hydrolysis of urea to ammonia and carbon dioxide by acid urease is a promising alternative to prevent urethane formation. Enzyme immobilisation, a well-established and mature technology, improves the stability and therefore economic viability of the process, especially at an industrial scale. Amyloids are highly organized fibrillar structures made of proteins which can be assembled producing nanotubes. Biological nanotubes demonstrated to be a suitable support for enzyme immobilization due to the robust mechanical properties and ease of functionalization of individual fibrils for specific applications.The present project is intended to immobilize the acid urease on biological nanotubes and to compare the performance with that immobilized on Eupergit® C 250 L both in model and real wines. Once the behavior of whole and crunched biocatalysts at different enzyme loadings has been compared to that of the free enzyme to assess the contribution of diffusional effects, it would be interesting to compare the performance of such immobilized derivatives in a laboratory-scale packed-bed cartridge at different space velocities using firstly a model wine solution and then a real white wine laced with urea.Expected results: The expertise in enzyme immobilization (Viterbo, Italy) combined with the know-how in biological nanotubes (Tucumán, Argentina) and the study of the modeling aspects of the reactor and the immobilized system (Roma, Italy) will encourage the interdisciplinary work between the universities contributing to the scientific knowledge and potentially improving the safety of technology in wine production.