Isolation of a Cellulolytic Enzyme Producing Microorganism, Culture Conditions and Some Properties of the Enzymes

Abstract

A fungus was isolated from soil as a cellulolytic enzyme-producing microorganism. This wild strain, named fungal strain Y-94, secreted a large amount of cellulolytic enzyme components consisting of 0.8 units of avicelase, 9.2 units of carboxymethyl cellulose (CMC)-hydrolyzing enzyme (CMCase) and 2.0 units of β-glucosidase per ml of culture broth on cultivation in Mandels medium for 7 to 10 days at 30°C, and also produced in the culture filtrate various other polysaccharide- hydrolyzing enzymes such as xylanase, β-1,3-glucanase, amylase, etc. Higher productivity of the cellulolytic enzymes (avicelase, 6.5 units/ml; CMCase, 82 units/ml; β-glucosidase, 25 units/ml; and filter paper units (F.P.U.),* 5.0 units/ml) was obtained by altering the medium composition. The maximum production of the cellulolytic enzymes was observed when this strain was cultured in a medium containing 4% cellulose powder, 1% peptone, 0.6% KNO₃, 0.2% urea, 1.2% KH₂PO₄, 0.16% KCl, 0.12% MgSO₄ 7H₂0, 0.001% MnSO₄ 6H₂0, 0.001% CuSO₄ 7H₂0 and 0.1% Tween 80 or polyethylene glycol 1000, pH 4.0, under the same culture conditions.