Evaluation of Cellulases Production by Aspergillus niger Using Response Surface Methodology

The recent developments in bioconversion of agricultural and industrial wastes to ‎chemical feedstock led to extensive studies on cellulolytic enzymes produced by fungi ‎and bacteria. Aspergillus niger is well known for its ability to produce cellulases. This ‎study aimed to produce cellulolytic enzymes from A. niger. Thirteen isolates of ‎Aspergillus niger were screened for cellulases production. A. niger 270 was the best one ‎which formed the highest inhibition zone (9cm) with hydrolysis capacity of 1.32. This ‎isolate was used for cellulases production and then optimization of endoglucanase and ‎exoglucanase activities, in addition to protein and biomass production in broth by using ‎response surface methodology. The Box-Behnken Design method with 3-factors and 3-‎levels was used. The maximum endoglucanase and exoglucanase activities were 10.37 ‎and 6.81 IU/ml respectively, while protein and biomass reached 137.33 mg/ml and 14.39 ‎g/l at the optimal conditions which were 7 days incubation period, 3% cellulose mixture ‎concentration and 0.35% ammonium sulfate concentration.‎