Abstract:
Homogenized bagasse-cellulose activated by NaOH and treated in turn with sodium periodate, urea, formaldehyde, was used in the fixation of papain as a fast reactional carrier. The binding capacity of the enzyme protein was related to the duration of formaldehyde treatment and enzyme fixation as well as the concentration of solution enzyme. The optimum time for formaldehyde treatment was fourteen hours. After papain was fixed for eighteen hours, the papain-combining capacity of the carrier tended to remain stable. The range of optimum concentration of solution enzyme was 1 to 2. 5 mg/ml raw enzyme. The recovery rate for fixed papain activity reached 34. 5%. The half-life was 35 days. The Km values (casein as substance % w/v)and optimum pH values for fixed papain and solution papain were 0.12%and 8. 0, 0. 26% and 8. 5 respectively. The optimum temperature for both of them was 60-70 degree Celsivs. Fixed papain showed substrate inhibition as solution papain also did. The activity of fixed papain treated with 6 mol/L urea for six hours tended to be stable, and was 46. 7% of the orginal activity.The clarification of beer treated with fixed papain was raised by 2-9.25 times, and the content of protein in beer decreased by 78. 8%, the treated beer refrigerated for 120 days did not show turbidity, while the original flavour of the beer and other physical and chemical indices remained unchanged.