Depolymerization of Chitosan with the Aid of Pepsin

摘要

A kind of pepsin was used to depolymerize chitosan. Four factors of reaction were studied including concentration of enzyme, pH, temperature and time. The concentration of pepsin influenced the depolymerization of chitosan efficiently, the other three factors had little effect on the reaction-pH was from 3.0 to 6.0, temperature from 30℃ to 60℃ , time from 2 hours to 8 hours. Experimental results revealed that the enzymatic process did not appear to obey a simple kinetic model; Chitosan with average molecular weights in the range 5 - 10 × 10~5 could be easily depolymerized to highly polydisperse chitosans with the average molecular weight about 1 × 10 under the conditions: pH 4.0; 30℃ ; 8hrs; pepsin 4.0 mg/ml.