Optimization of lipase production from Aspergillus sp. isolated from olive mill wastewater under solid-state fermentation

Document Type : Research Article


1 Department of Chemical Engineering, Faculty of Eng., University of Guilan, Rasht

2 Associate Professor, Department of Chemical Engineering, University of Guilan

3 Associate Professor, Department of Chemistry, Payame Noor University, Qazvin Center

4 Assistant Professor of Chemical Engineering, University of Guilan


Lipases are a group of hydrolases capable of catalyzing the hydrolysis of triacylglycerols to free fatty acids and glycerol. They are very important industrial enzymes because of the potential to be used in many industrial applications. In this research, potent lipase producer fungi were isolated and screened from olive mill wastewater and its disposal pond. In the qualitative test, 7 strains were identified as lipase producer fungi. One of the 7 isolated fungi, was identified based on macroscopic and microscopic examination as Aspergillus sp. that detected good lipase activity. The L25 Taguchi orthogonal array design of experiments with four factors in five levels was used to reach optimal fermentation conditions and medium composition for lipase production using Minitab 19 software. The optimum conditions derived were: WS/OF content ratio (0.5), fermentation time (7 days) and moisture content 1:2 (66%), glucose concentration as a co-substrate (0 g/L). Using optimal fermentation conditions, maximum lipase activity (2754.73 U/g of the dry substrate) was obtained. The results demonstrated that the fungus isolated is a promising alternative for lipase production. This study aimed to better understand the microorganisms in OMW and take them to the potential candidates for the conversion of agricultural by-products into valuable secondary metabolites like lipase.


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