Extracellular Endoglucanase and Exoglucanase Enzymes Production by Trichoderma viride Utilizing Olive Mill Wastewater (OMW) in liquid fermentation

Background:The cellulase enzyme is one of the most industrially important enzymes. Its cost represents a significant barrier to other valuable commercial products. Reducing the cost of cellulase production is an important approach. Objectives: For this purpose, this work investigated the production of cellulase enzyme using olive oil production waste (olive mill wastewater (OMW). Materials and methods: The ability of Trichoderma viride to utilize OMW as a substrate for cellulase production was studied. Optimization of cellulase production was investigated to find out the optimum OMW concentration, agitation speed, aeration rate, and cellulose addition. Results:The results showed that 75% v/v OMW submerged shake flask culture was the most suitable culture for T. viride growth and cellulase enzyme production (0.82 U/ml endoglucanase activity and 0.25 U/ml exoglucanase activity). When this culture was supplemented with cellulose, the activity of endoglucanase and exoglucanase was significantly improved (10.24 U/ml and 2.17 U/ml respectively).The agitation speed of 200 rpm enhanced the production to reach 9.1 U/ml of endoglucanase and 6.38 U/ml of exoglucanase. The effect of the aeration rate on enzyme production was studied under batch cultivation. The highest cellulase activity was at 2.0 vvm, where the endoglucanase and exoglucanase activities were 55.96 U/ml and 32.62 U/ml respectively. Conclusions: Therefore, it is claimed that OMW is a suitable medium for cellulase enzyme production after optimization of the process.