| Autor: |
Correa KCS; Department of Chemistry, Federal University of Sao Carlos, 13565-905 Sao Carlos, Brazil., Facchinatto WM; Aveiro Institute of Materials, CICECO, Department of Chemistry, University of Aveiro, St. Santiago, 3810-193 Aveiro, Portugal., Habitzreuter FB; Sao Carlos Institute of Chemistry, University of Sao Paulo, Ave. Trabalhador Sao-carlense 400, 13560-590 Sao Carlos, Brazil., Ribeiro GH; Brazilian Corporation for Agricultural Research, Embrapa Instrumentation, St. XV de Novembro 1452, 13560-970 Sao Carlos, Brazil., Rodrigues LG; Department of Chemistry, Federal University of Sao Carlos, 13565-905 Sao Carlos, Brazil., Micocci KC; Department of Chemistry, Federal University of Sao Carlos, 13565-905 Sao Carlos, Brazil., Campana-Filho SP; Sao Carlos Institute of Chemistry, University of Sao Paulo, Ave. Trabalhador Sao-carlense 400, 13560-590 Sao Carlos, Brazil., Colnago LA; Brazilian Corporation for Agricultural Research, Embrapa Instrumentation, St. XV de Novembro 1452, 13560-970 Sao Carlos, Brazil., Souza DHF; Department of Chemistry, Federal University of Sao Carlos, 13565-905 Sao Carlos, Brazil. |
| Abstrakt: |
This study evaluates the activity of a recombinant chitinase from the leaf-cutting ant Atta sexdens (AsChtII-C4B1) against colloidal and solid α- and β-chitin substrates. 1 H NMR analyses of the reaction media showed the formation of N-acetylglucosamine (GlcNAc) as the hydrolysis product. Viscometry analyses revealed a reduction in the viscosity of chitin solutions, indicating that the enzyme decreases their molecular masses. Both solid state 13 C NMR and XRD analyses showed minor differences in chitin crystallinity pre- and post-reaction, indicative of partial hydrolysis under the studied conditions, resulting in the formation of GlcNAc and a reduction in molecular mass. However, the enzyme was unable to completely degrade the chitin samples, as they retained most of their solid-state structure. It was also observed that the enzyme acts progressively and with a greater activity on α-chitin than on β-chitin. AsChtII-C4B1 significantly changed the hyphae of the phytopathogenic fungus Lasiodiplodia theobromae , hindering its growth in both solid and liquid media and reducing its dry biomass by approximately 61%. The results demonstrate that AsChtII-C4B1 could be applied as an agent for the bioproduction of chitin derivatives and as a potential antifungal agent. |
