Estudos em biocatálise com células íntegras de Geotrichum candidum e Lipase de Burkholderia cepacia imobilizadas em sílicas funcionalizadas

Abstract

In biocatalytic processes with free cells or enzymes some difficulties must be overcome, for example, the compromise of the stability of the biocatalysts in the reactional processes deserves special attention. It is in this direction that this thesis proposes to contribute to the development of new strategies in biocatalysis, having as main scope to investigate the catalytic potential of Geotrichum candidum CCT 1205 cells and Burkholderia cepacia lipase immobilized onto functionalized silicas for applications in organic reactions such as Baeyer-Villiger and enzymatic transesterification. The results showed that the use of live cells of G. candidum CCT 1205 in Baeyer-Villiger reactions allowed rapid conversion of cyclic ketones to ɛ-caprolactone when compared to other microorganisms already reported. The presence of the carrier containing the immobilized microorganism provided evidence of stabilization of the cell medium by decreasing the toxicity of the substrate to the cells when in more concentrated media. Biotransformation of acetophenone without addition of glucose favors the formation of phenol. After 72 hours of reaction, the composition of the products yielded 46.9 and 45.5% of the phenol and 1phenylethanol respectively. Burkholderia cepacia lipase immobilized on functionalized silica demonstrated biocatalytic potential in transesterification reaction.