EN
Microbial extradiol dioxygenases have a great potential in bioremediation, but their structure is very sensitive to various environmental and chemical agents. Immobilization techniques make the enzyme properties’ improvement possible. This is the first report of the usage of κ-carrageenan as a matrix for the immobilization of catechol 2,3-dioxygenase. The storage stability of entrapped catechol 2,3-dioxygenase from Stenotrophomonas maltophilia KB2 in κ-carrageenan hydrogel at 4ºC was found up to 14 days, while the free enzyme lost its activity within 24 hours. The immobilization of dioxygenase decreased the optimum temperature by 10ºC, while both soluble and immobilized enzyme showed similar pH properties. The Km, Vmax, and Hill constant values for the immobilized enzyme were 0.17 μM, 106.68 mU, and 1.00, respectively. The immobilized catechol 2,3-dioxygenase showed higher activity against 3-methylcatechol, hydroquinone, and tetrachlorohydroquinone than the soluble enzyme. Immobilization of catechol 2,3-dioxygenase protected the enzyme from inhibition and enhanced its resistance to inactivation during catalysis.