CHARACTERIZATION OF PRODUCTION AND ENZYME PROPERTIES OF AN ENDO-BETA-1,4-GLUCANASE FROM BACILLUS-SUBTILIS CK-2 ISOLATED FROM COMPOST SOIL

Bacillus subtilis CK-2, isolated from garden organic waste compost, wa s found to have high hydrolytic activity against carboxymethylcellulos e (CMC) due to the secretion of an endo-beta-1,4-glucanase. Enzyme pro duction was related to the sporulation process, and was regulated by t he concentration of readily metabolizable carbohydrate in growth mediu m. Enzyme production did not require CMC or other cellulose containing materials. The endo-1 beta-1,4-glucanase activity was optimal at pH 5 .6-5.8 and at 65 degrees C, and achieved thermal stability up to 55 de grees C. The activity was inhibited by Hg2+. The purified enzyme gave a single band corresponding to a MW of 35.5 kDa on SDS-PAGE, while the Sephadex G-75 chromatography revealed a molecular weight of the activ e enzyme around 70 kDa, indicating a dimeric form of the active enzyme . The enzyme activity was irreversibly inhibited by SDS. Native PAGE a nd IEF revealed three different isoelectric forms of the enzyme, all w ith an identical N-terminal amino-acid sequence.