title: Chitin hydrolysis assisted by cell wall degrading enzymes immobilized of Thichoderma asperellum on totally cinnamoylated D-sorbitol beads.
abstract: In this study, cell wall degrading enzymes produced by Thrichoderma asperellum (TCWDE) were immobilized on totally cinnamoylated D-sorbitol (TCNSO) beads and used for chitin hydrolysis. In order to optimize immobilization efficiency, the reaction time was varied from 2 to 12 h and reactions were conducted in the presence or absence of Na2SO4. Immobilized enzymes were analysed concerning to thermal and operational stability. Immobilization in presence of Na2SO4 was 54% more efficient than immobilization in absence of salt. After optimization, 32% of the total enzyme offered was immobilized, with 100% of bounding efficiency, measured as the relation between protein and enzyme immobilized. Free and TCNSO-TCWDE presented very similar kinetics with maximum hydrolysis reached at 90 min of reaction. Thermal stability of both free and TCNSO-TCWDE was similar, with losses in activity after 55 °C. Moreover, free and TCNSO-TCWDE retained 100% activity after 3h incubation at 55 °C. TCNSO-TCWDE were used in a bath-wise reactor during 14 cycles, producing 1825 μg of N-acetylglucosamine (NAG) maintaining 83% of initial activity.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Instituo de Ciências Biológicas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970 Goiânia, GO, Brazil. katia@icb.ufg.br
authors.forename: Kátia F
authors.initials: KF
authors.lastname: Fernandes
authors.forename: David
authors.initials: D
authors.lastname: Cortijo-Triviño
authors.forename: Karla A
authors.initials: KA
authors.lastname: Batista
authors.forename: Cirano J
authors.initials: CJ
authors.lastname: Ulhoa
authors.forename: Pedro A
authors.initials: PA
authors.lastname: García-Ruiz
mesh_terms: D002473:Cell Wall / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism*; D002934:Cinnamates / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006868:Hydrolysis; D013012:Sorbitol / Q000737:chemistry*; D014242:Trichoderma / Q000201:enzymology*
chemical_list: D002934:Cinnamates; D004800:Enzymes, Immobilized; D002686:Chitin; C029010:cinnamic acid; D013012:Sorbitol