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Abstract

The aim of this investigation was achieved by exposing native Aspergillus niger (WldAN) to an ultraviolet (UV) germicidal lamp (256 nm) kept at a distance of 40 cm for a time interval ranging from 2 -14 minutes, in a total of 56 minutes and finally using the improved strain to synthesize a more stable cellulase. The results showed growth improvement of the modified isolate with a density of 3.54 g/ml at the 9 th hour as compared to 3.36 g/ml density of the native strain at the 7 th hour on the 3 rd day. Cellulase produced by submerged fermentation at 25 o C for 4 days using the native Aspergillus niger (WldAn) and modulated Aspergillus niger (UVAn) respectively recorded activities of 3.50 U/ml at 60 o C and 2.85 U/ml at pH 4.0 as compared to 2.40 U/ml at 50 o C and 2.24 U/ml at pH 5.0 recorded for cellulase synthase from the native strain.