Evaluation of cellulases production by Aspergillus niger using response surface methodology

Document Type : Original Research Articles.

Authors

1 Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, Egypt

2 Botany and Microbiology Department, Faculty of Science,Assiut University, Assiut, Egypt

3 faculty of sugar and integrated industry

Abstract

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.

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