| Autor: |
Monteiro RRC; Departamento de Engenharia Química, Universidade Federal do Ceará, Campus do Pici, Bloco 709, CEP 60455760, Fortaleza 60000-000, CE, Brazil., Neto DMA; Departamento de Química Analítica e Físico-Química, Universidade Federal do Ceará, Campus do Pici, Bloco 940, CEP 60455760, Fortaleza 60000-000, CE, Brazil., Fechine PBA; Departamento de Química Analítica e Físico-Química, Universidade Federal do Ceará, Campus do Pici, Bloco 940, CEP 60455760, Fortaleza 60000-000, CE, Brazil., Lopes AAS; Instituto de Engenharias e Desenvolvimento Sustentável, Universidade da Integração Internacional da Lusofonia Afro-Brasileira, Campus das Auroras, CEP 62790970, Redenção 68550-000, CE, Brazil., Gonçalves LRB; Departamento de Engenharia Química, Universidade Federal do Ceará, Campus do Pici, Bloco 709, CEP 60455760, Fortaleza 60000-000, CE, Brazil., Dos Santos JCS; Instituto de Engenharias e Desenvolvimento Sustentável, Universidade da Integração Internacional da Lusofonia Afro-Brasileira, Campus das Auroras, CEP 62790970, Redenção 68550-000, CE, Brazil., de Souza MCM; Instituto de Engenharias e Desenvolvimento Sustentável, Universidade da Integração Internacional da Lusofonia Afro-Brasileira, Campus das Auroras, CEP 62790970, Redenção 68550-000, CE, Brazil., Fernandez-Lafuente R; Departamento de Biocatálisis, ICP-CSIC, Campus UAM-CSIC Cantoblanco, 28049 Madrid, Spain. |
| Abstrakt: |
The synthesis of ethyl butyrate catalyzed by lipases A (CALA) or B (CALB) from Candida antarctica immobilized onto magnetic nanoparticles (MNP), CALA-MNP and CALB-MNP, respectively, is hereby reported. MNPs were prepared by co-precipitation, functionalized with 3-aminopropyltriethoxysilane, activated with glutaraldehyde, and then used as support to immobilize either CALA or CALB (immobilization yield: 100 ± 1.2% and 57.6 ± 3.8%; biocatalysts activities: 198.3 ± 2.7 U p -NPB /g and 52.9 ± 1.7 U p -NPB /g for CALA-MNP and CALB-MNP, respectively). X-ray diffraction and Raman spectroscopy analysis indicated the production of a magnetic nanomaterial with a diameter of 13.0 nm, whereas Fourier-transform infrared spectroscopy indicated functionalization, activation and enzyme immobilization. To determine the optimum conditions for the synthesis, a four-variable Central Composite Design (CCD) (biocatalyst content, molar ratio, temperature and time) was performed. Under optimized conditions (1:1, 45 °C and 6 h), it was possible to achieve 99.2 ± 0.3% of conversion for CALA-MNP (10 mg) and 97.5 ± 0.8% for CALB-MNP (12.5 mg), which retained approximately 80% of their activity after 10 consecutive cycles of esterification. Under ultrasonic irradiation, similar conversions were achieved but at 4 h of incubation, demonstrating the efficiency of ultrasound technology in the enzymatic synthesis of esters. |
