Exploring the effects of treatments with carbohydrases to obtain a high-cellulose content pulp from a non-wood alkaline pulp

• Published in: Carbohydrate polymers Vol. 133; pp. 302 - 312
• Main Authors: Beltramino, Facundo, Valls, Cristina, Vidal, Teresa, Roncero, M. Blanca
• Format: Journal Article Publication
• Language: English
• Published: England Elsevier Ltd 20.11.2015
• Subjects: Agave - chemistry; Biocatalysis; Carbohydrase; Carbohydrases; Cellulose; Cellulose - chemistry; Cellulose - isolation & purification; Cel·lulosa; Cel·lulosa per a paper; Endo-1,4-beta Xylanases - metabolism; Endoglucanase; Enginyeria paperera; Enzymatic treatment; Glycoside Hydrolases - metabolism; High-cellulose content; Hydrolysis; Investigació; Non-wood pulp; Pasta paperera; Polpa de fusta; Sodium Hydroxide - chemistry; Wood-pulp; Xylanase; Xylanases; Àrees temàtiques de la UPC; Enzymatic treatment; Endoglucanase; Carbohydrase; Xylanase; Non-wood pulp; High-cellulose content
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2015.07.016

•A high reduction (82%) in hemicelluloses content was achieved with treatments.•Direct admixture of xylanase provided better results, with 25% xylan reduction.•Cx appeared as a new very promising catalyst with both used enzymatic activities.•Enzymes catalytic mechanism was assessed via HPLC analysis of effluents.•Enzymatic treatments produced up to a 110% increase in pulp reactivity. In this work, treatments with a xylanase (X) and carbohydrases mixture (Cx) were applied on a TCF bleached sisal pulp in order to obtain high-cellulose content fibers applicable on a wide range of uses. A limit of ≈12% w/w final content in hemicelluloses was found regardless of the enzymatic treatment assessed. An extraction with 4% and 9% w/v NaOH was performed for further hemicelluloses removal. We found that NaOH dose could be strongly reduced if combined with Cx or Cx+X treatments. Also, if necessary, a stronger reduction could be obtained with 9% w/v NaOH, which was found to be boosted in a 14% if performed after a treatment with Cx. An end-product with a low content in xylans (≈2.9% w/w) and in HexA (5.8μmol/odp) was obtained. Pulp Fock solubility was also increased (≈30%) by enzymatic treatments. HPLC analysis of effluents provided useful information of enzymatic catalytic mechanisms.