Production of cellulases by a wild strain of Gliocladium virens: optimization of the fermentation medium and partial characterization of the enzymes

The medium composition was optimized on a shake-flash scale for production of cellulases by Gliocladium virens using the Graeco-Latin square technique. With the optimized medium 0.33 units of filter paper (FP)-cellulase, 1.52 units of β-glucosidase, and 30.45 units of xylanase were produced per millilitre of culture filtrate at 120 h of fermentation. In a laboratory fermentor the lag phase was much reduced and 0.25 units of FP-cellulase, 0.77 units of β-glucosidase, and 24.04 units of xylanase were obtained per millilitre of culture filtrate at 39 h. Characterization of the enzymes with respect to pH and temperature optima, and pH and heat stabilities indicated that cellulases and xylanase of G. virens have properties comparable to those of Trichoderma reesei and some other fungi.