GROWTH AND CELLULASE ACTIVITY OF WILD-TYPE ASPERGILLUS NIGERANL301 IN DIFFERENT CARBON SOURCES

A wild-type Aspergillus niger (ANL301) isolated from wood-waste in Lagos, Nigeria, produces extracellular proteins with cellulase (EC 3. 2. 1. 4) activity. Three different carbon sources (Glucose, Cellulose and Sawdust) influenced the organism’s growth and the production of extracellular cellulase enzymes. Best growth was obtained with glucose at 72 hours of incubation. The peak mycelia weight of 1.56 mg/ mL obtained with glucose was about 3 times the maximum weight of 0.58 and 0.49 mg/ mL respectively obtained with cellulose and sawdust at 96 hours. The peak protein contents of the culture filtrates were 0.02, 0.15 and 0.69 mg/ mL respectively in the media containing glucose, cellulose and sawdust. There was no significant cellulase activity in the filtrates from glucose-containing media. The culture filtrates of the organism from cellulose- and sawdust-containing media yielded significant cellulase activities with maximum values of 105.6 Units /L (at 72 hours for cellulose) and 101.9 Units /L (at 144 hours for sawdust). There is a correlation between the protein content and cellulase activity of the culture filtrates. Sawdust can serve as a low-cost substrate for cellulase production by the organism.