CARBOXYMETHYL-CELLULASE FROM ERWINIA-CHRYSANTHEMI .2. PURIFICATION AND PARTIAL CHARACTERIZATION OF AN ENDO-BETA-1,4-GLUCANASE

The extracellular CM-cellulase of E. chrysanthemi, strain 3665, had a marked tendency to form aggregates when concentration and/or storage time of culture supernatant were increased. In submitting an unconcentrated glycerol culture supernatant to ion exchange chromatography, 1 major endo-.beta.-1,4-glucanase could be isolated with a high degree of purity and partially characterized. The molecular size was 45 kilodaltons. The isoelectric point was 4.3. The enzyme rapidly decreased the viscosity of CM-cellulose with a slow increase in the reducing sugars produced. It displayed its highest activity towards CM-cellulose at a pH between 6.2-7.5. It had a significant capacity to hydrolyze amorphous cellulose such as phosphoric acid-swollen cellulose. The major products of this degradation were cellobiose and cellotriose. It exhibited a very low activity on microcrystalline cellulose. Glucose and cellobiose did not affect significantly its activity against CM-cellulose.