| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1088-1 | ||||
Resumo:Xylanase (EC 3.2.1.8) is a hydrolytic hemicellulase responsible for catalyzing the cleavage of the β-1,4 bond of xylans. It is used in industrial processes such as cellulose pulp bleaching, bioethanol production and additives in monogastric feed. Enzyme immobilization study is an interesting option to improve the stability of enzymatic processes, in addition to providing the reuse of these biocatalysts. This study aimed to immobilize xylanase from the fungus Penicillium crustosum on solid supports of monoaminoethyl-N-aminoethyl-agarose (MANAE-agarose) and chitosan magnetic nanoparticles, as well as to evaluate its reuse. P. crustosum xylanase was obtained from cultivation in Czapek liquid medium supplemented with corn straw and incubated for 6 days in BOD at 28 ºC. The extracellular extract obtained after filtering the cultures with the aid of a vacuum pump, and after dialysis in deionized water, the sample was applied to DEAE-Sephadex chromatographic columns. The MANAE-agarose and chitosan magnetic nanoparticles supports were activated with glutaraldehyde followed by the addition of the xylanase enzyme diluted in 50 mM sodium phosphate buffer pH 7.2, under continuous stirring at a temperature of 25 ºC. Aliquots of the xylanase-MANAE-agarose derivative and chitosan magnetic nanoparticles were taken at different times (0, 15, 30, 60, 120, 240 minutes and 24 hours) to monitor the course of immobilization by enzymatic dosages. After immobilization, cycles of reuse of the derivatives were performed, and after each cycle, the derivatives were washed with the optimal pH buffer for enzymatic activity. The immobilization yield of P. crustosum xylanase on MANAE-glutaraldehyde-agarose support was 86.69% and chitosan magnetic nanoparticles were 87.15%. However, regarding the immobilization efficiency and recovered activity, the MANAE-glutaraldehyde support obtained 29.11% and 25.23%, while the chitosan magnetic nanoparticles obtained 20% and 18.73%, respectively. The derivative with chitosan magnetic nanoparticles maintained 76.79% of its initial activity after 13 cycles, which was superior compared to the MANAE-glutaraldehyde derivative which maintained 40%. Thus, it can be concluded that the xylanase from P. crustosum was successfully immobilized and stabilized on both solid supports, generating a new derivative with good yield and reuse. Palavras-chave: xylanase, Penicillium crustosum, immobilization, reuse Agência de fomento:CAPES, CNPq, Fundação Araucária and UNIOESTE. | |||||