Isolation, Identification and Screening of Lipase Producing Fungi from the Soil Environment of Ilorin Metropolis

Abstract

This investigation was carried out to isolate, identify and screen for lipase producing fungal species present in the soil environment of Ilorin metropolis. Soil samples of approximately 200g each were collected randomly from eight different locations within the Ilorin metropolis for the investigation. Potato Dextrose Agar was used for the isolation of the fungal species by pour plate method. Six fungal species, Penicillium spp, Acremoniumspp, Mucors pp, Rhizopus stolonifer, Aspergillus nigerand Aspergillus flavuswere isolated and screened for their ability to produce lipases on tween-20 and phenol red agar. The results obtained for lipase production on tween-80 and phenol red after 5 days of incubation showed that four isolates were positive for lipase production which was indicated by diameter zone of clearance and visible precipitate of calcium monolaurate due to the deposition of calcium crystal. The result further revealed that Aspergillus niger had the highest lipase producing ability (having a diameter zone of clearance of 14 ± 0.05 mm), followed by Rhizopus stolonifer (having 10 ± 0.05 mm). Aspergillus flavus and Mucor sp had 6 ± 0.03 mm, 6± 0.01 mm respectively. Acremonium sp. and Penicillium sp. had no zone of clearance. These results demonstrate the presence of lipase producing fungi in the soil environment of Ilorin metropolis,Kwara State, and these can be harnessed locally for large scale production of the enzyme which is of value commercially in the production of leather, detergent,textiles and also as constituents of some special diets and pharmaceuticals.