Lipase de Rhizomucor miehei imobilizada para produção de ésteres com potencial de aplicação industrial a partir de ácidos graxos de óleo de pequí (Caryocar brasiliense sp.).

Abstract

Lipases, triacylglycerol ester hydrolase E.C. 3.1.1.3, are enzymes that act on ester bonds of triacylglycerols, releasing organic acids and glycerol. Among the different media used in enzyme immobilization stands out chitosan, an organic support consisting of a natural polymer widely used due to its low cost. This work aims to apply the Rizhomucor lipase enzyme miehei immobilized on chitosan aiming to use in obtaining esters obtained from fatty acids derived from the hydrolysis of Pequí oil (Caryocar brasiliense sp.) With potential application in the pharmaceutical industry. It is extremely important to conduct this study, aiming to promote use of alternative regional products such as oils, immobilizing supports, contributing to the expansion and diversification of industrial biotechnology and promoting the synthesis of expensive compounds such as esters from raw material low cost. Initially there was the immobilization of the enzyme in the organogel chitosan base as well as the quantification of its activity. Subsequently esterification was performed assays from fatty acids Pequí oil in different proportions of ethanol under stirring of 150 rpm at 37 ° C in a 24 hour period. Esterification assays were performed on starch present in the reaction medium as a desiccant or adsorbent. It is given the acid value of the initial and final means to know the income produced esters. The lipase immobilized form showed activity of 0.56 U/g, obtained a 76% yield of fatty acids. There was maximum conversion value of the tests performed with lipase immobilized form in the molar ratio 1: 1 with 56.67% of esters formed in the reaction without the presence of desiccant and 70.53% conversion in the reaction medium with agent presence. With the increase in molar ratio, there was a decrease in the formation of esters due to the increased concentration of alcohol, forming a barrier preventing access of fatty acids to the active site of the enzyme by removing the protective aqueous layer structure of the enzyme. Making use of the starch in the reaction medium allowed to prevent the presence of residual water formed during the esterification reaction did not promote hydrolysis of esters formed, favoring an increase of the conversion.