Electrospun biosystems made of nylon 6 and laccase and its application in dyes removal

Electrospun materials, due to the possibility of design of their properties, are suitable as supports for enzyme immobilization. Produced biocatalytic systems might be then apply in various biocatalytic reactions, including conversion of pollutants. In our study, electrospun fibers made from nylon 6 was produced, modified and applied as a support for laccase immobilization by adsorption and covalent binding. The systems with immobilized laccase were used in decolorization process of selected dyes, azo dye Reactive Black 5 and the anthraquinone dye Reactive Blue 4. It was found that at from dye solution at concentration 1 mg/L at pH 5, temperature 25 °C, after 24 h of process the efficiency of decolorization of Reactive Blue 4 and Reactive Black 5 reached 77% and 63%, respectively. The storage stability studies showed that after 30 days of storage, the relative activities were 60% and 95% for adsorbed and covalently bonded oxidoreductase respectively. Moreover, after 10 consecutive catalytic cycles adsorbed and covalently bonded laccase retained over 60% and 70% respectively, indicating the possibility of application of the obtained systems on a larger scale for removal of phenolic pollutants from wastewaters.