Anais do Congresso Paranaense de Microbiologia
IV Congress of Microbiology in Paraná

Lipases are enzymes that have the ability to catalyze the hydrolysis of long chain triacylglycerols and release fatty acids, diacylglycerols, monoacylglycerols and glycerol. In addition to their hydrolytic action, lipases catalyze other synthesis reactions such as esterification, transesterification, lactonization, acidolysis, alcoholysis and aminolysis. They are an exceptionally multifunctional biocatalyst, with a broad industrial application, for example in the food, paper and cellulose, pharmaceutical, textile industries, in the formulation of detergents, inorganic synthesis, in the production of biodiesel, in the treatment of sewage, among others. Thus, in this study, we aimed to characterize the lipases produced by the fungal strain T5-4A. The lipase activity was measured by incubating the crude enzyme filtrate in a substrate containing 0.5 mM p-nitrophenyl palmitate (pNPP), solubilized in DMSO diluted 20 times in McIlvaine buffer pH 7.0, with Triton X-100 at 0. 5% at 37°C. Absorbance reading was performed at 405 nm. A unit of enzymatic activity was defined as corresponding to the release of 1 µmol of pNPP per minute of reaction per mL of sample, under the assay conditions. The enzyme showed maximum activity at 45°C, and at acidic pH (5.5). Furthermore, the lipases exhibited greater stability at 40 °C, and remained more stable at pH range 5.5 to 7.0. Regarding the effect of different substances and ions on the lipase activity, it was found that Na+ (10 mM) and Mg+2 (2 mM and 10 mM) ions activated enzyme activity, while Cu+2 (2 mM and 10 mM), Mn+2 (10 mM) and Hg+2 (2 mM and 10 mM) ions and EDTA (2 mM and 10 mM) were enzyme inhibitors. These results obtained in this study indicate possible industrial applications for the studied lipases, such as products synthesis in fine chemicals, environmental applications, and in the food and pharmaceutical industries. Hence, the study affirms the importance of carrying out the characterization of enzymes, as it aims to identify the conditions that provide greater activity and stability of the enzymes and verify whether it has the necessary characteristics for specific industrial applications, in order to ensure a better performance of the enzyme in the reactions in which it is used.