Effect of delignification on hemicellulose extraction from switchgrass, poplar, and pine and its effect on enzymatic convertibility of cellulose-rich residues

Abstract

Hemicellulose is an abundant and underutilized carbohydrate polymer in plants. The objective of this study was to understand the effect of delignification on hemicellulose extraction efficiency with different types of lignocellulosic biomass. In the case of pine, with a prior sodium chlorite or peracetic acid delignification, more than 50% of the original hemicellulose in the biomass could be extracted using a 10% sodium hydroxide solution; without delignification, only 3.4% of hemicellulose could be extracted from pine. In contrast, without prior delignification, acceptable hemicellulose extraction efficiencies (55.5% and 50.7%, respectively) were achieved from switchgrass and poplar. In addition, the effect of hemicellulose extraction processes on the enzymatic convertibility of the cellulose-rich residues after extraction was determined. The cellulose-rich residues from switchgrass after hemicellulose alkali extraction showed high glucose recovery with enzyme hydrolysis with or without prior delignification. For pine and poplar, high glucose recovery with enzyme hydrolysis of the cellulose-rich residues only occurred if the sample had a delignification step prior to hemicellulose extraction. This information on commercially available biomass feedstocks is useful for those considering isolating hemicellulose within a biorefinery concept.

Xylooligosaccharides produced from sugarcane leaf arabinoxylan using xylanase from Aureobasidium pullulans NRRL 58523 and its prebiotic activity toward Lactobacillus spp.

“…However, the SLX viscosity was lower than that of xylan with a similar structure, such as sugarcane bagasse xylan. Heavily branched xylans reportedly had lower viscosity than linear or sparsely branched ones [ 74 ]. The SLX viscosity reported here showed potential for certain applications, including the improvement of paper strength [ 71 , 73 ].…”

Cellulose Extraction from Coconut Coir with Alkaline Delignification Process

“…The results after delignification with alkaline NaOH pretreatment are dark brown which is affected by the color-causing substances contained in the coconut fiber, namely lignin. These was previous by research of Geng et al (2018), where delignification produces a darker color due to the higher lignin content [15]. Then, the cellulose fiber will be treated in the bleaching process by adding 5% NaOCl at 60 °C.…”

“…The cellulose content from coconut coir was obtained from the delignification, and bleaching process. The delignification process aims to remove lignin content in coconut fiber [15]. The existence of lignin can inhibit the determination process of cellulose.…”

CRISPR-Knockout of CSE Gene Improves Saccharification Efficiency by Reducing Lignin Content in Hybrid Poplar

“…After vacuum filtration and washing (5 mL of 10% (v/v) acetone three times), the filter paper was dried in an oven at 65 • C until a constant weight was obtained, which was then recorded. To extract hemicellulose [54], 4 mL of 10% (w/v) NaOH was added to 200 mg of the collected extractive-free samples above followed by a 3 h incubation at 50 • C with shaking. After vacuum filtration and washing (5 mL of distilled water three times), samples were dried (65 • C) until a constant weight was obtained, and the final weight of residue was recorded.…”