Autor(es)

Siqueira, Germano A. ^[1] ; Dias, Isabella K. R. ^[1] ; Arantes, Valdeir ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Lorena Sch Engn, Dept Biotechnol, Biocatalysis & Bioprod Lab, Lorena, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Biological Macromolecules; v. 133, p. 1249-1259, JUL 15 2019.
• Citações Web of Science: 0

Resumo

Cellulose nanocrystals (CNCs) is a high-value and emerging bionanomaterial with an increasing number of applications. The action of endoglucanases (EGs) from fungal and bacterial sources belonging to three glycosyl hydrolase (GH) families were investigated on bleached eucalyptus kraft pulp as potential catalysts to prepare CNC. Fungal GH7EG was the most efficient in hydrolysis and fiber fragmentation without altering crystallinity and crystallite size. Fiber fragmentation promoted by fungal GH45EG was similar to that observed for GH7EG, although it released a smaller amount of sugar. Bacterial GH5EG resulted in very low hydrolysis yield and practically did not fragment the fibers, resulting in a hydrolysis residue with characteristics very similar to the initial material. GH45EG was the only EG that affected the crystallinity and crystallite size and also the only enzyme capable of isolating nanoparticles. The isolated nanoparticles had very narrow width distribution range of 6-10 nm and length distribution range of 400-600 nm. Supplementation of beta-glucosidase and conventional mechanical refining as a pretreatment did not improve the release of nanoparticles. Despite catalyzing the same biochemical reaction, different EGs displayed very distinct action during hydrolysis. The reported strong binding of GH45EG's CBM to the cellulose and the lack of increased accessibility of the enzyme to new substrate likely allowed continuous hydrolysis of the few fibers available, resulting in the isolation of cellulose nanoparticles. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 15/02862-5 - NANOCEL - Desenvolvimento de preparos enzimáticos para o preparo de nanoceluloses por um processo biohídrido
• Beneficiário: Valdeir Arantes
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Jovens Pesquisadores
• Processo FAPESP: 15/00397-3 - Estudo da ação de endoglucanases no preparo de celulose nanocristalina
• Beneficiário: Germano Andrade Siqueira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado