Synergistic effects of enzyme pretreatment for hemicellulose separation from paper-grade pulp in ionic liquid/water
Herein, we studied the effects of pretreatment with glucanase (G), xylanase (X), and their combinations [G/X mixtures or sequential addition (G–X and X–G)] on the efficiency of ionic liquid/water (IL/w)—promoted extraction of hemicelluloses from paper-grade pulp. Mild G pretreatment effectively increased the efficiency and selectivity of hemicellulose removal, whereas severe G pretreatment resulted in high glucose loss and low selectivity. Under optimized conditions, G and X pretreatments achieved similar removal efficiencies, especially in IL/w systems with high water content (25 and 20%), whereas the former was inferior to the latter at low water content (15%). Simultaneous G/X treatment achieved more efficient and selective hemicellulose removal than sequential G–X and X–G treatments, with the former sequence outperforming the latter. Finally, sequential extraction with IL/w-20 and IL/w-15 allowed extremely effective hemicellulose removal, decreasing the xylose content of pulp to 1.5%.
KeywordsGlucanase Xylanase Ionic liquid/water extraction Hemicellulose separation Chemical pulp
The authors acknowledge the support from the Canada Research Chairs Program, National Natural Science Foundation of China (Grant Nos. 31500488 and 31770632), Natural Science Foundation of Fujian Province (Grant Nos. 2016J01089 and 2016H6004).
- Kuzmina O, Sashina E, Troshenkowa S, Wawro D (2010) Dissolved state of cellulose in ionic liquids—the impact of water. Fibers Text East Eur 18:32–37Google Scholar
- Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D, Crocker D (2008) Determination of structural carbohydrates and lignin in biomass. LAP-002 NREL analytical procedure National Renewable Energy Laboratory, Golden, COGoogle Scholar
- Suurnäkki A, Heijnesson A, Buchert J, Tenkanen M, Viikari L, Westermark U (1996) Location of xylanase and mannanase action in kraft fibers. J Pulp Pap Sci 22:78–83Google Scholar