Characterization of a new lipase purified from Fusarium verticillioides and its application in hydrolysis of sardine oil and biodiesel production

Lipases comprise a subclass of esterases and represent a group of enzymes which catalyze the hydrolysis and synthesis of esters formed from glycerol and long-chain fatty acids. The sardine oil hydrolysis release omega-3 as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and represents the first step in the synthesis of functional ingredients. The objective of this study was to biochemically characterize a new lipase purified from Fusarium verticillioides and apply this purified enzyme in sardine oil hydrolysis. The crude extract was purified in one step using octil Sepharose and desorbed with 0.3% Triton-X100. The lipase activity was measured with 4-nitrophenylpalmitate as substrate. The pH and temperature optimal as well as the pH and thermal stability were evaluated along with ion influence, isoelectric point and Km. The optimal pH obtained was 6.0 and the pH stability was about 80% in the range of pH 5.0-8.0 withing 3h of incubation The optimum temperature was 40°C and the lipase was 60% thermo stable at 30-40°C for 3h. Ca⁺⁺ and Ba⁺⁺ positively influenced the activity. The isoelectric point was 5.18, Km (0.373) and Vmax (77.61 U.mg^-1) values were determined according to Lineweaver and Burk, with a R² 0.96. The sardine oil hydrolysis was evaluated with this enzyme being immobilized in octil Sepharose and showed a great conversion of 6% in EPA and 2.4% in DHA. The enzyme was able to produce biodiesel, however in a low conversion tax, around 4%. Improvements as genetic engineering have been done in order to increase this yield.