Evaluation of Lipase Production Efficiency by Fungi Isolated from Mint Roots (Mentha) Using Various Oily Carbon Sources

Abstract

This study aimed to evaluate the ability of several fungal species isolated from the roots of the mint plant (Mentha) to produce the extracellular enzyme lipase using different vegetable oils as carbon sources. The fungal genera identified through morphological and microscopic examination included Penicillium sp., Aspergillus spp., Fusarium oxysporum, Aspergillus niger, Aspergillus flavus, and Alternaria alternata. The experiments were conducted on solid media supplemented with coconut oil, olive oil, and corn oil to detect enzymatic activity through the formation of a transparent halo around the colonies. Results indicated significant variations in the efficiency of the isolates depending on the carbon source and incubation period. Aspergillus spp. demonstrated the highest enzymatic efficiency of 70% in olive oil on the fourth day of incubation. This was followed by Penicillium sp., which reached an efficiency of 66% on the seventh day when grown in coconut oil. Aspergillus niger showed its peak activity of 39% in olive oil by the seventh day, while Aspergillus flavus produced 21% activity in coconut oil on the third day. Fusarium oxysporum recorded a lower activity of 14% in olive oil on the seventh day, and Alternaria alternata failed to exhibit any lipase production or halo formation across all tested oils. The findings suggest that vegetable oils, particularly olive and coconut oils, serve as effective substrates for inducing fungal lipase production, offering a biological alternative for industrial enzyme applications.