Facilitating enzymatic hydrolysis with a novel guaiacol-based deep eutectic solvent pretreatment

AbstractCellulolytic enzymes can readily access the cellulosic component of lignocellulosic biomass after the removal of lignin during biomass pretreatment. The enzymatic hydrolysis of cellulose is necessary for generating monomeric sugars, which are then fermented into ethanol. In our study, a combination of a deep eutectic (DE) mixture (of 2-aminoethanol and tetra-n-butyl ammonium bromide) and a cyclic ether (tetrahydrofuran) was used for selective delignification of rice straw (RS) under mild conditions (100 °C). Pretreatment with DE-THF solvent system caused ~ 46% delignification whereas cellulose (~ 91%) and hemicellulose (~ 67%) recoveries remained higher. The new solvent system could be reused upto 10 subsequent cycles with the same effectivity. Interestingly, the DE-THF pretreated cellulose showed remarkable enzymatic hydrolysability, despite an increase in its crystallinity to 72.3%. Contrary to conventional pretreatments, we report for the first time that the enzymatic hydrolysis of pretreated cellulose is enhanced by the removal of lignin during DE-THF pretreatment, notwithstanding an increase in its crystallinity. The current study paves way for the development of newer strategies for biomass depolymerization with DES based solvents.

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Process optimization for deep eutectic solvent pretreatment and enzymatic hydrolysis of sugar cane bagasse for cellulosic ethanol fermentation

Renewable Energy ◽

10.1016/j.renene.2021.05.131 ◽

2021 ◽

Author(s):

Yao Liu ◽

Xiaojie Zheng ◽

Shunhui Tao ◽

Lei Hu ◽

Xiaodong Zhang ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Process Optimization ◽

Sugar Cane ◽

Ethanol Fermentation ◽

Cellulosic Ethanol ◽

Deep Eutectic Solvent ◽

Sugar Cane Bagasse ◽

Hydrolysis Of

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Facile fractionation of lignocelluloses by biomass-derived deep eutectic solvent (DES) pretreatment for cellulose enzymatic hydrolysis and lignin valorization

Green Chemistry ◽

10.1039/c8gc03064b ◽

2019 ◽

Vol 21 (2) ◽

pp. 275-283 ◽

Cited By ~ 93

Author(s):

Xiao-Jun Shen ◽

Jia-Long Wen ◽

Qing-Qing Mei ◽

Xue Chen ◽

Dan Sun ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Deep Eutectic Solvent ◽

Enzymatic Saccharification ◽

Lignin Valorization

A recyclable and green biomass-derived deep eutectic solvent (DES) pretreatment was developed to deconstruct the recalcitrant structure of Eucalyptus for further cellulose enzymatic saccharification and lignin valorization.

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Assessment of Natural Deep Eutectic Solvent Pretreatment on Sugar Production from Lignocellulosic Biomass

MATEC Web of Conferences ◽

10.1051/matecconf/201815201014 ◽

2018 ◽

Vol 152 ◽

pp. 01014 ◽

Cited By ~ 5

Author(s):

Yoon Li Wan ◽

Yuen Jun Mun

Keyword(s):

Enzymatic Hydrolysis ◽

Lignocellulosic Biomass ◽

Choline Chloride ◽

Deep Eutectic Solvent ◽

Economic Feasibility ◽

Effect Of Temperature ◽

Sago Waste ◽

Natural Deep Eutectic Solvent ◽

Hydrolysis Of ◽

Sugar Loss

Before the conversion of lignocellulosic biomass into fuel such as ethanol, the biomass needs to be pretreated and the yield of ethanol is highly dependent on the pretreatment efficiency. This study investigate the performance of deep eutectic solvent (DES) in pretreating sago waste which is a type of starchy biomass. The suitable type of DES in sago waste pretreatment was selected based on three criteria, which is the structural characteristic, the sugar yield during enzymatic hydrolysis and the amount of sugar loss during pretreatment. In this study, three types of DES namely Choline Chloride-Urea (ChCl-Urea), Choline Chloride-Citric acid (ChCl-CA) and Choline Chloride-Glycerol (ChCl-Glycerol) was investigated. The effect of temperature and duration on DES pretreatment was also investigated. All DES reagents were able to disrupt the structure and increase the porosity of sago waste during pretreatment. ChCl-Urea was selected in this study as it shows apparent structural disruption as examined under Scanning Electron Microscope (SEM). The highest glucose yield of 5.2 mg/mL was derived from enzymatic hydrolysis of ChCl-Urea pretreated sago waste. Moreover, reducing sugar loss during ChCl-Urea pretreatment was low, with only 0.8 mg/mL recorded. The most suitable temperature and duration for ChCl-Urea pretreatment is at 110°C and 3 hr. In a nutshell, the application of DES in pretreatment is feasible and other aspects such as the biodegradability and recyclability of DES is worth investigating to improve the economic feasibility of this pretreatment technique.

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