The main challenges of biocatalytic processes are the development of highly active, robust and stable biocatalysts, efficient regeneration and prevention of biocatalyst deactivation. Magnetic particles represent a flexible carrier for the immobilization of enzymes or cells, as they have a large specific surface area with the possibility of functionalization and enable easy immobilization of the biocatalyst with an external magnetic field. In the present work, we developed a microfluidic device in which we effectively immobilized bacterial spores with the help of magnetic particles. We examined the influence of pH and different magnetic particles on the laccase activity of spores. We also studied the effect of pH and different ratios between the amount of magnetic particles and spores on the immobilization efficiency in a magnetic field. At the optimal conditions, which were immobilization pH 2,5, MagP-NH2 magnetic particles and the mass ratio of magnetic particles to spores 2,2, the immobilization efficiency in the flow system was 97 %, the retained laccase activity of spores with MagP-NH2 magnetic particles was 88 % for the batch system at pH 4. A microreactor with immobilized spores in a magnetic field was used for the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid. During the flow reactions, we found that more than 83 % of the spores are retained in the reactor within 5 hours of the process. The concentration of the product at the outlet of the microreactor was monitored outside the system with a UV/VIS spectrophotometer, as well as with an integrated miniaturized flow spectrophotometer, which enables data acquisition in real time.
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