Shesterenko Y. Biotechnology of Agaricus bisporus tyrosinase immobilization on polymeric supports for phenolic compounds oxidation

Dissertation is devoted to biocatalysts of phenolic compounds oxidation biotechnology development, based on immobilized mushroom Agaricus bisporus tyrosinase for phenols removal from aqueous solutions and separation of their mixtures. Using the modified method, the partially purified tyrosinase preparation, heterogeneous according to electrophoretic data, with 3-fold increased phenoloxidase activity, was obtained. The conditions of certain phenolic compounds oxidation, using by tyrosinase, were optimized (pH 6,5, t 25 ?C, enzyme activity 25-1000 U/cm3, ? 30-180 min). Methods of tyrosinase immobilization by entrapment in calcium alginate, poly-N-vinylcaprolactam, and modified poly-N-vinylpyrrolidone gels, were developed. Highly active, stable enzymatic preparations were obtained. With a help of biocatalysts obtained, it was accomplished quantitative phenol oxidation during 4-12 cycles of usage, for it's elimination and separation of phenolic compounds mixtures. Application of QSPR analysis allowed to predict bioconversion degree of tyrosinase substrates studied, depending on their structure, based on phenol molecule compound form, dipole moment, lipophilicity and electronic polarizability of molecules. Using the aluminium-potassium, aluminium-ammonium and ferric-ammonium alums, the quantitative elimination of phenolic compounds oxidation products was accomplished. The developed method of phenols removal by immobilized in calcium alginate Agaricus bisporus tyrosinase was successfully approved on waste water of Odessa's CJSC "TeploService".