PURIFICATION AND CHARACTERIZATION OF 2 BETA-MANNANASES FROM TRICHODERMA-REESEI

Five enzymes with mannanase activity were separated from Trichoderma r eesei culture filtrate using analytical isoelectric focusing and subse quently detected with the zymogram technique. The crude enzymes had is oelectric points in the range of 3.6-6.5. Two of the mannanases with p l values of 4.6 and 5.4 were purified using ion-exchange chromatograph y, affinity chromatography and chromatofocusing. The molecular weights determined with SDS-PAGE were 51 000 (mannanase pI 4.6) and 53000 (ma nnanase pI 5.4). The two enzymes had similar properties with respect t o pH optimae and pH stabilities. Both mannanases hydrolyzed ivory nut mannan mainly to mannotriose and mannobiose. The specific activities ( against locust bean gum) of the purified enzymes were 1860 and 1430 nk at mg-1 for the pI 4.6 and pI 5.4 mannanases, respectively.