Physiological studies of cellulase complex enzymes of Aspergillus oryzae and characterization of carboxymethyl cellulase

Investigation of the production of cellulase complex enzymes by the fungus Aspergillus oryzae on soluble bio- cellulosic waste like cheese whey was the goal of this work. The effects of incubation period, substrate concentration, initial pH and temperature on the production of endoglucanase, exoglucanase and cellulase (filter paper activity FPA) activities, were investigated. Seven days incubation period with an initial pH value of 6 and temperature of 40°C, and cheese whey concentration of 10% yielded the highest specific activities with 1.5 fold increases for endoglucanase and 1.4 fold increases for exoglucanase. Cellulase specific activity represented as FPA showed no fold increase at all. The optimum temperature of endoglucanase was observed at 55°C, and the enzyme activity has abroad pH range between 3.8 to 8.0 and 24.91% of the original activity was retained after heat treatment at 90°C for 30 min. Analysis of the partial purified enzyme preparation by SDS – PAGE revealed one protein band showing cellulolytic activity, The molecular weight of this band was estimated to be around 45.000 Daltons. Key words: Cellulolytic enzymes, Aspergillus oryzae, cheese whey, dinitrosalicylic acid(DNS), fermentation variables.