Has endoglucanase activity on substrates containing beta-1,4 glycosidic bonds, like in carboxymethylcellulose (CMC). Endohydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans. Optimum pH is 4.0. Optimum temperature is 30 degrees Celsius. Induced by Co(2+), Ba(2+), Mn(2+), Mg(2+) and Cu(2+) ions. Repressed by Hg(2+) ions and methanol.