Chitosan/Siloxane Hybrid Polymer: Synthesis, Characterization and Performance as a Support for Immobilizing Enzyme
نویسندگان
چکیده
O polímero híbrido derivado de siloxano e quitosana foi obtido pela técnica sol-gel, tendo como precursor o tetraetilortosilicato (TEOS). O suporte híbrido obtido foi modificado quimicamente com epicloridrina e utilizado para imobilizar lipase de Burkholderia cepacia. O híbrido SiO2-quitosana deu origem a uma nova estrutura macromolecular na qual as partículas inorgânicas encontramse dispersas em escala nanométrica na matriz orgânica e ligadas à matriz por meio de ligações covalentes. Foi realizado um estudo comparativo entre a lipase livre e a imobilizada quanto à influencia do pH e temperatura, parâmetros cinéticos e estabilidade térmica. O pH ótimo para a atividade máxima de hidrólise da lipase imobilizada foi de 6,1, enquanto que para a lipase livre foi de 7,0. A temperatura ótima permaneceu em 50 oC mesmo depois da imobilização. Os perfis de estabilidade térmica indicaram que o processo de imobilização foi favorável à estabilização da enzima e o derivado epóxi SiO2-quitosana foi cerca de 30 vezes mais estável que a lipase livre a 60 oC.
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