Imobilização de lipase de Rhizomucor miehei em organo-gel: desenvolvimento de um catalisador para produção de ésteres.

Abstract

Enzymes act as highly efficient catalysts during the course of chemical reactions, however despite their excellent prospects and advantages over chemical catalysts to its application in industry is not so immediate for some features such as solubility in the reaction medium, and instability operating. Organo-gels which are supports for immobilization has allowed to overcome the disadvantages mentioned, and when immobilized lipase in this system the assembly shown an ideal catalyst for the production and processing of bioactive compounds, such as esters. Esterification reactions are employed in the production of compounds of high added value in various industrial sectors. The aim of this study was to obtain stable catalyst Rhizomucor miehei lipase in low-cost carriers with the addition of microemulsion aiming to use this catalyst in the production of esters. The supports were prepared using two polymers as jelly, gelatin and chitosan being applied in these different gels. Hexane was used as the organic phase and the surfactant sodium dodecyl sulfate (SDS), two for the synthesis of organo-gels. The activity of the derivatives were determined for subsequent applications on other tests such as thermal stability, which found the half-life and the stability factor. The conversion was analyzed by 24-hour test at 37 ° C with stirring samples, measuring the initial acidity and the end of the reaction medium. The catalyst chitosan base proved more resilient and showed greater activity compared to gelatin. In the stability tests, the chitosan derivative base had a greater half-life and greater stability factor than the free enzyme, thus, it was applied in esterification reactions. The higher conversion obtained was 80.0% in molar ratio acid / alcohol 1: 1 in assays without the desiccant, and the use of starch that conversion decreased to 68.16%. Conversion ratios for all fell in both tests when the amount of alcohol used was increased. This conversion also declined when applied starch testing. It is presumed that large amounts of alcohol inhibited and / or denatured enzyme and the starch is not optimized assays, whereas there was a drop in the conversion of values for assays with this desiccant.