Lipolytic Activities of Bacteria and Fungi Isolated from Soil Samples

Abstract

This study was carried out at the Department of Microbiology, Microbiology Laboratory, Ado-Ekiti State University, Ekiti State, Nigeria between July, 2018 to March, 2019. Due to the diverse biotechnological importance of lipases as a biocatalytic enzyme, extracellular production of microbial lipases has to gain lots of interest. This study, therefore, focused on the physicochemical parameters of lipase producing microorganisms from different soil samples. Microorganisms were isolated from four different soil samples using Nutrient Agar (NA) and Potato Dextrose Agar (PDA). The isolates were identified and characterized. Production, an assay for Lipase enzymes, purification, the effect of pH, Temperature and metal ion was investigated. The isolates were culturally, morphologically and biochemically characterized. Two of the bacteria strains (Bacillus sp. and Staphylococcus sp.) and four fungi (Fusarium sp., Aspergillus fumigatus, Aspergillus niger, and Trichophyton sp.) isolates were able to produce lipid using Sudan Black B Fat staining techniques. Fusarium sp. isolated from dumpsite soil had the highest specific lipase activity (21.16 µmol/min/ml) while Bacillus sp. isolated from red oil spill soil had the highest lipase activity (0.59 µmol/min/mg). The specific activity of partially purified lipase for Fusarium sp. was 2.39 µmol/min/mg while Bacillus sp. had a specific activity of 2.46 µmol/min/mg. 30oC - 50oC, pH 7.0 to 9.0 and KCl2 (139.672%) supported the highest production of lipase by the Bacillus sp. and Fusarium sp. This study demonstrated that the Bacillus sp. produced a high amount of lipase activity followed by Fusarium sp. Extensive and persistent screening for new microorganisms and their lipolytic activities will help to provide faster ways to solve most environmental soil pollution.