[Comparative characteristic of activity of urease, incorporated into polysiloxane hydrogels and xerogels, obtained by sol-gel technique].

Polysiloxane hydrogels with incorporated urease (degree of immobilization is 79-88%) that retains fermentative activity at the level of 56-84% were obtained by sol-gel technique. An influence of polysiloxane matrix functionalization on a degree of incorporation, activity retention and a factor of efficiency of urease immobilization was studied. Polysiloxane matrix functionalization with methyl groups causes decreasing a degree of ferment immobilization and a factor of immobilization efficiency. Functionalization of polysiloxane matrix with 3-aminopropyl groups leads to practically quantitative incorporation of the enzyme. And the highest degree of urease activity retention and maximal factor of its immobilization were observed at 3-aminopropyl groups content in polysiloxane matrix equals 2-5% (mol.). Transformation of hydrogels into xerogels via vacuum drying causes decreasing urease fermentative activity on nearly 2 orders.