Effect of temperature and PH on activity of purified cellulase obtained from Aspergillus flavus

In view of the fact that temperature and pH play key role in the activity of fungal cellulases, this experiment was designed to assess the effect of temperature, and pH on activity of the purified enzyme from Aspergillus flavus derived from rotten wood. The characterization of the purified cellulase enzyme of Aspergillus flavus was carried out using carboxymethyl cellulose, filter paper and cotton wool assays. The maximum and optimum temperatures were 900C and 700C respectively. The pH optima were between 5 and 8. The enzyme retained above 50% of its original activity at 100 0C for 1h and up to 80% at 80 0C for 1h. It was stable over a pH range of 5-8, and retained up to 40% of its original activity at pH 9. The study carried out showed that the purified Aspergillus flavus cellulases demonstrated useful properties among which include; high optimum temperature, increased thermal stability at both acidic and alkaline pH. They also offer additional advantage as they are more rigid than meso enzymes and moreover, are more resistant to thermal and chemical denaturation. Hence are remarkable tools for developing commercial biotechnologies and for studying protein stability.

Keywords:

Aspergillus , flavus , Characterization , Purified , cellulose , Temperature , Thermal , stability , PH activity and relative activity