Screening of Microorganisms Isolated from Different Environmental Samples for Extracellular Lipase Production

Abstract

Lipases are hydrolytic enzymes that hydrolyse triglycerides to free fatty acids and glycerol and those from microbes have occupied a prominent position as industrial biocatalysts. Microorganisms isolated from oil polluted environmental samples were screened for their lipase producing ability. A total of thirty seven bacteria and seventeen fungal strains belonging to the genera Trichoderma (16 spp.) and Aspergillus (1 sp.) were obtained from the samples. Acinetobacter sp. had the highest frequency of occurrence (37.8%). The lipolytic activity of the bacteria when screened on solid agar ranged within 3.0m - 15.5amm, 3.0n - 15.5amm and 3.0 - 16a mm at 24, 48 and 72 hours of incubation, respectively. Acinetobacter sp. (OG3) had the highest activity at different hours of incubation. Eight isolates did not show any activity throughout the incubation period. On submerged fermentation, the growth of the lipolytic bacteria ranged within 0.093 - 1.003 in which Acinetobacter sp. had the highest growth while Bifidobacterium sp. had the lowest. Lipase production ranged within 1.25 U/ml - 8.65 U/ml in which Acinetobacter sp. had the highest production. During submerged fermentation, the growth of the selected fungal isolate ranged within 0.00 - 0.200a , 0.00 - 0.25a and 0.00 - 0.3190a in which T. FISO1 had the highest at 3 and 7 days of incubation while T. virens FSU/AW3 had the highest at 14 days of incubation. There was a significant difference in lipase production by the fungi, it ranged within 0.70n - 12.35a U/ml, 1.8k - 19.15a U/ml and 2.50n - 19.8a U/ml in which Hypocrea patella FAD1, T. stromaticum FSUAW1 and T. virens FSU/AW3 had the highest at day 3, 7 and 14, respectively. The study has shown that the bacteria and Trichoderma strains isolated are potential lipase producers.