Abstract
AbstractIn order to confirm the contribution of delignification to the increase in lignocellulosic cellulose digestibility, several laboratory oxidative pretreatments under mild conditions, including alkaline-hydrogen peroxide (AP), two-step alkaline/peracetic acid (APAA) and sodium chlorite (SC) pretreatments were employed to achieve selective delignification of sugarcane bagasse and retained most of the hemicelluloses (xylan) in the pretreated solids. Four commercial cellulase cocktails were used to test the enzymatic hydrolyzability of pretreated substrates. Results revealed that delignification indeed could greatly improve the final (120 h) cellulose hydrolysis with relatively high final (120 h) glucan conversion (> 90%) by different cellulase cocktails even if the substrates still had a high hemicelluloses content. However, the xylan conversion seemed to be more greatly dependent on the pretreatments and cellulase cocktails used. AP and APAA pretreatments resulted in the disappearance of middle lamella and liberation of cellulose fibers with significant etching, deformation and fracture of cell wall structure. SC pretreatment greatly modified the sugar bagasse surface morphology to make the surface much coarser. The cell wall also underwent serious fracture and deformation with some middle lamella disappearing. However, no significant alteration on the structure of pure cellulose was observed by SC oxidative pretreatment of filter paper. Oxidative pretreatment might also modify lignin structure and surface properties thus greatly reducing the non-specific adsorption of enzymes. The obtained results strongly support the conclusion that delignification under mild pretreatment condition can be very helpful to improve the enzymatic hydrolysis of lignocellulosic cellulose by commercial cellulase cocktails even if the substrates has a high hemicelluloses content.
Funder
National Key R & D Program of China
National Natural Science Foundation of China
Publisher
Springer Science and Business Media LLC
Subject
Renewable Energy, Sustainability and the Environment,Biomedical Engineering,Food Science,Biotechnology
Reference40 articles.
1. Adney B, Baker J. (2008) Measurement of cellulase activities (Laboratory Analytical Procedure), Technical Report NREL/TP-510-42628, National Renewable Energy Laboratory, Golden, CO. https://www.nrel.gov/docs/gen/fy08/42628.pdf
2. Beecher JF, Hunt CG, Zhu JY (2009) Tools for the characterization of biomass at the nanometer scale. In: Lucia LA, Rojas OJ (eds) The nanoscience and technology of renewable biomaterials. Blackwell Publishing Ltd, New Jersey, pp 61–90. https://doi.org/10.1002/9781444307474.ch3
3. Bhalla A, Cai CM, Xu F, Singh SK, Bansal N, Phongpreecha T, Dutta T, Foster CE, Kumar R, Simmons BA, Singl S, Wyman CE, Hegg EL, Hodge DB (2019) Performance of three delignifying pretreatments on hardwoods: hydrolysis yields, comprehensive mass balances, and lignin properties. Biotechnol Biofuel. 12:213. https://doi.org/10.1186/s13068-019-1546-0
4. Chen HM, Zhao XB, Liu DH (2016) Relative significance of the negative impacts of hemicelluloses on enzymatic cellulose hydrolysis is dependent on lignin content: evidence from substrate structural features and protein adsorption. ACS Sust Chem Eng. 4:6668–6679. https://doi.org/10.1021/acssuschemeng.6b01540
5. Chen YA, Zhou Y, Qin YL, Liu DH, Zhao XB (2018) Evaluation of the action of Tween 20 non-ionic surfactant during enzymatic hydrolysis of lignocellulose: pretreatment, hydrolysis conditions and lignin structure. Bioresour Technol 269:329–338. https://doi.org/10.1016/j.biortech.2018.08.119
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