PURIFICATION AND CHARACTERIZATION OF AN EXTRACELLULAR CHITOSANASE PRODUCED BY AMYCOLATOPSIS SP CSO-2

Extracellular chitosanase produced by Amycolatopsis sp. Cs0-2 was puri fied to homogeneity by precipitation with ammonium sulfate followed by cation exchange chromatography. The molecular weight of the chitosana se was estimated to be about 27,000 using SDS-polyacrylamide gel elect rophoresis and gel filtration. The maximum velocity of chitosan degrad ation by the enzyme was attained at 55 degrees C when the pH was maint ained at 5.3. The enzyme was stable over a temperature range of 0-50 d egrees C and a pH range of 4.5-6.0. About 50% of the initial activity remained after heating at 100 degrees C for 10 min, indicating a therm ostable nature of the enzyme. The isoelectric point of the enzyme was about 8.8. The enzyme degraded chitosan with a range of deacetylation degree from 70% to 100%, but not chitin or CM-cellulose. The most susc eptible substrate was 100% deacetylated chitosan. The enzyme degraded glucosamine tetramer to dimer, and pentamer to dimer and trimer, but d id not hydrolyze glucosamine dimer and trimer.