Belo, Isabel

Domínguez, José Manuel

Oliveira, Felisbela Maria Araújo

Pérez-Bibbins, B.

Pérez-Rodríguez, N.

Torrado Agrasar, A.

Universidade do Minho: RepositoriUM

577II Congreso Iberoamericano sobre BiorrefineríasCorncob is an interesting lignocellulosic subproduct ob-tained from maize, whose importance lies on the high production of this cereal as the main diet contributor on several countries as México or Brazil. The high xylose content of corn hemicelluloses makes this waste a largely available renewable source of xylose for obtaining high value-added products by means of biotechnological processes. The production by yeast fermenta-tion of xylitol, a pentitol with high sweetening power and anticariogenic properties suitable for diabetics, is a good example of this strategy of valo-rization, whose successfulness depends on the extent of the corn xylan hy-drolysis to xylose. Although acid and hydrothermal treatments have shown good efficiencies, the enzymatic hydrolysis offers the advantage of avoiding the generation of microbial inhibitors as hydroxymethylfurfural and furfu-ral. Complete enzymatic xylan hydrolysis is hindered by hemicellulose het-erogeneity among different lignocellulosic materials, which makes necessary the use of enzymatic mixtures including xylanases, arabinosidases and feru-loyl esterases among others.The aim of this work was the comparison of the performance of commercial enzymes and a fungal extract obtained by solid-state fermen-tation of corncob by Aspergillus niger, for the enzymatic generation of xylose 3.17 ENZYMATIC GENERATION OF xYLOSE FROM CORNCOB FOR xYLITOL PRODUCTIONPérez-Bibbins, B.1Pérez-Rodríguez, N.1Araújo-Oliveira, F.M.2Belo, I.2Torrado Agrasar, A.1Domínguez, J.M.11 Department of Chemical Engineering, Faculty of Sciences, University of Vigo (Campus Ou-rense), As Lagoas s/n, 32004 Ourense, SPAIN. Email: pbbelinda@uvigo.es 2 IBB – Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710–057 Braga, Portugal.5782nd Iberoamerican Congress on Biorefineriesfrom corncob and subsequent fermentation by Debaryomyces hansenii for the production of xylitol.The better degrees of xylan hydrolysis were obtained when the Aspergillus extract and Ultraflo® L (Novozymes), both containing feruloyl esterase activity, were used. Although Ultraflo showed higher ability for gen-erating reducing sugars, the Aspergillus extract was more efficient than the commercial enzyme for producing xylose. These results point to the interest of using enzymatic extracts for corncob xylan to xylose hydrolysis that are specifically produced by microorganisms grown on the same material to be hydrolyzed.Keywords: corn cob, enzymatic hydrolysis, xylitol, xylose

Enzymatic generation of xylose from corncob for xylitol production

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Universidade do Minho: RepositoriUM

Universidade do Minho: RepositoriUM