Cellulase Production by Penicillium expansum MDFS2 Using Mixed Substrates of Barley Straw and Wheat Straw

Document Type : Research Paper

Authors

1 MSc Graudate, Department of Biology, Islamic Azad University, Urmia Branch, Urmia, Iran

2 Assistant Professor, Department of Biology, Islamic Azad University, Urmia Branch, Urmia, Iran

Abstract

The production of cellulase from Penicillium expansum MDFS2 on mixed substrates of barley straw and wheat straw (1:1) was investigated. The highest exoglucanase (6.72 U/g) and endoglucanase (40.75 U/g) activities observed on the 5th day of fermentation process. However, the highest β-glucosidase activity (15.47 U/g) was on the 6th day of fermentation process. The optimum temperature for exoglucanase and β-glucosidase activity recorded at 40°C and β-glucosidase retained more than 70% of its maximum enzymatic activity at 80°C. Also, the highest endoglucanase activity was recorded at 50°C. The highest activity for all the three major components of cellulase enzyme complex was observed at pH= 5.0. The enzyme activity reduced with increasing in temperature and incubation period. The results showed that β-glucosidase is more stable at 50°C in comparison of endoglucanase and exoglucanase and also 80% of β-glucosidase original activity was maintained 3-h after incubation period. According to the results of this study, Penicillium expansum MDFS2 could be suggested as a strain with good potential for the growth on the mixed substrates of barley straw and wheat straw for cellulase production.

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