RESPONSE OF IMMOBILIZED BACILLUS-SUBTILIS ALPHA-AMYLASE TO HIGH-PRESSURE TREATMENT

Immobilized enzymes, advantageous for use in bioreactors, are difficul t to decontaminate. Inactivation of microorganisms by high hydrostatic pressure could be a gentle decontamination method, provided the immob ilized enzyme is stable enough. Loss in activity of alpha-amylase from Bacillus subtilis covalently bound to sepharose, after 10-30 minutes of pressure treatment at 300, 450 and 600 MPa at 50 and 70 degrees C a nd pH 8, and after 10-30 minutes of heat treatment at 50 and 70 degree s C and pH 8, was distinctly lower than that of equally treated non-im mobilized B. subtilis alpha-amylase with and without sepharose. At 100 MPa reaction was accelerated by 5%.