O. Heichalsegal et al., IMMOBILIZATION IN ALGINATE-SILICATE SOL-GEL MATRIX PROTECTS BETA-GLUCOSIDASE AGAINST THERMAL AND CHEMICAL DENATURATION, Bio/technology, 13(8), 1995, pp. 798-800
We have developed a novel immobilization medium by soaking enzyme-cont
aining calcium alginate beads in a solution of tetramethoxy-ortho-sili
cate (TMOS) in hexane. Water-soluble alkyl siloxanes, resulting from t
he partial hydrolysis of TMOS at the hexane-water interface permeated
the alginate gel, polymerized and formed a colloid within the beads. S
ilicate-alginate beads were robust, and did not deform under pressure.
The composite gel demonstrated the excellent protein retention and th
ermal stabilization properties typical of silicate sol-gel-immobilizat
ion, as well as protection against inactivation by concentrated urea s
olutions. Immobilized beta-glucosidase had complete operational stabil
ity at ambient temperature for at least several months.