RESUMO
The use of an immobilized Serratia. sp W3 lipase as a replacement for the standard pancreatic lipases in the hydrolysis of liver oil from the Musteleus mustelus was studied. Monoacylglycerols (MAGs) and diacylglycerols (DAGs) containing ω-3 polyunsaturated fatty acids, namely eicosapentaenoic and docosahexaenoic acids were produced in hexane solvent at reaction temperatures reaching 55 °C with a molar triacylglycerol conversion over than 75 ± 5% in 24 h showing excellent hydrolysis characteristics. The favorable conditions for the hydrolysis reaction allowed fats with higher melting points to be analyzed facilitating the coupling of the hydrolysis reaction to the later steps in the analytical protocol. The lipid composition was elucidated for the first time by employing a highly efficient UHPLC-MS method with a novel embedded linear retention index approach. MAGs and DAGs obtained during the enzymatic hydrolysis could be used for the production of glycerol based emulsifiers of nutritional interest.
Assuntos
Diglicerídeos/química , Ácidos Graxos Ômega-3/análise , Óleos de Peixe/química , Lipase/metabolismo , Monoglicerídeos/química , Animais , Biocatálise , Cromatografia Líquida de Alta Pressão , Diglicerídeos/metabolismo , Enzimas Imobilizadas/metabolismo , Ácidos Graxos Insaturados/análise , Óleos de Peixe/metabolismo , Hidrólise , Espectrometria de Massas , Monoglicerídeos/metabolismo , Serratia/enzimologia , Tubarões , Triglicerídeos/metabolismoRESUMO
A newly isolated Serratia sp. W3 strain was shown to secrete a non-induced lipase in the culture medium. Lipolytic activity was optimized using the response surface methodology (RSM) and the extracellular lipase from Serratia sp. W3 (SmL) was purified to homogeneity with a total yield of 10% and its molecular mass was estimated of about 67â¯kDa by SDS-PAGE. The amino acid sequence of the first 7â¯N-terminal residues of SmL revealed a high degree of homology with other Serratia lipase sequences. The purified SmL can be considered as thermoactive lipase, its maximal specific activity measured at pHâ¯9 and 55⯰C was shown to be 625â¯U/mg and 300â¯U/mg using tributyrin and olive oil emulsion as substrate, respectively. In contrast to other described Serratia lipases, SmL was found to be stable at a large scale of pH between pHâ¯5 and pHâ¯12. SmL was also able to hydrolyze its substrate in presence of various oxidizing agents as well as in presence of surfactants and some commercial detergents. Then, considering the overall biochemical properties of SmL, it can be considered as a potential candidate for industrial and biotechnological applications, such as synthesis of biodiesel and in the detergent industry.