The Enzyme-producing Conditions and Characteristics of Cellulases of a Cellulose-decomposing Strain YN1

Abstract:

Aspergillus sp. YN1, with cellulase activity, was screened from sheep and cattles feces compost. Different conditions for liquid fermentation which including carbon source, nitrogen source, temperature, pH, capacity of oxygen and inoculum age for the production of cellulases had been studied. The CMCase activity was 0.53 U/mL and the Filter-Paper activity was 0.15 U/mL when YN1 was cultured in the optimized condition for 3 d. In the study of characteristics of cellulases, the optimal reaction temperature was at 70°C and the optimal reaction pH was at 4.0 (in a 30-min reaction period). The cellulase activity retained above 80% when the celluases were treated under the conditions that the temperature was from 30°C to 50°C for 1 h or the pH from 3.0 to 4.0 for 2 h, which showed the celluases produced by YN1 have resistance to heat and acid.

Key words:Aspergillus sp., Cellulase activity, Fermentation condition optimization, Characteristics of cellulases