An enzyme carrier is prepd. by coating 0.1-0.25 mm mineral particles with chitosan [9012-76-4] and binding it with glutaraldehyde [111-30-8], which may be reduced by NaBH4. Alternatively, an enzyme may be bonded to the chitosan layer by a carbodiimide to stabilize the enzyme. Thus, 8 g chitosan in 300 mL HOAc + 400 mL water was left overnight with a suspension of 120 g silica gel, transferred to a glutaraldehyde soln. for 2 h, and agitated gently with an invertase [9001-57-4] soln. at pH 4 which immobilized 89% of the enzyme without any loss of activity. [on SciFinder (R)]