Evolution of the Lignin Chemical Structure during the Bioethanol Production Process and Its Inhibition to Enzymatic Hydrolysis

Abstract

To illuminate the lignin evolution after hydrogen peroxide presoaking prior to ammonia fiber expansion (H-AFEX) pretreatment and enzymatic hydrolysis, ball-milled wood lignins were separated from untreated corn stover, H-AFEX-treated corn stover, and enzymatic hydrolyzed residue, labeled as UN-L, HA-L, and EH-L, respectively. The structural features of EH-L were compared with HA-L and UN-L by elemental analysis, GPC, FT-IR, and NMR. The inhibition deriving from lignin loading and the structure were assessed by adding UN-L/HA-L in enzymatic hydrolysis. The thermogravimetric analysis and thermal degradation kinetics analysis of EH-L were performed to evaluate its industrial utilization. The results showed that a significant decline in molecular weight was observed in EH-L, while the polydispersity index was almost unchanged. The decrease of the G unit and the increase of the S unit were shown in EH-L when comparing to UN-L. The G unit had the strongest inhibition to enzymatic hydrolysis, and the increasing relative proportion of S/G in lignin was beneficial for enzymatic hydrolysis. The resinol structure in lignin was relatively stable after pretreatment and enzymatic hydrolysis. The thermogravimetry analysis indicated that the EH-L exhibited better thermal stability than that of UN-L, offering potential to prepare lignin-based heat-resistant epoxy resin and new flame-resistant materials.

Geographical traceability and multielement analysis of edible and medicinal fungi: Taking Wolfiporia cocos (F.A. Wolf) Ryvarden and Gilb. as an example

“…In addition, powdered W. cocos samples were digested by using an automatic microwave digestion system in the study. It is known from the related studies that the emerging potential pretreatment methods, such as presoaking and enzymatic hydrolysis, may will help the complete release of multielement s in the sample (Zhao et al., 2020). In the future study of elements, different pretreatment methods can be considered.…”

The Anti-colitis Effect of Schisandra chinensis Polysaccharide Is Associated With the Regulation of the Composition and Metabolism of Gut Microbiota

“…In present study, SCP is prepared by boiling in water, and it may not be the most effective method for extracting polysaccharide from Schisandra chinensis. The emerging potential methods of pretreatment and extraction of active components with ammonia and hydrogen peroxide (Zhao et al, 2017a(Zhao et al, , 2020a and pre-soaking (Zhao et al, 2017b;Qiao et al, 2018) may bring unexpected insights into the material basis of Schisandra chinensis. In addition, Schisandra chinensis contains water, and the determination of water content may be performed before extraction (Zhang et al, 2019), which contributes to accurate determination of polysaccharide in future research.…”

Effects of different drying methods on the chemical constituents of Lilium lancifolium Thunb. based on UHPLC‐MS analysis and antidepressant activity of the main chemical component regaloside A

“…The data mining of fingerprint information and bioactivity research can find the stable characteristic components in Chinese medicinal materials, which can make the quality and efficacy of TCM be associated, and help to clarify the mechanism of TCM. At present, the main methods to study the fingerprint of TCM are LC (UHPLC/high-performance liquid chromatography), gas chromatography, and infrared spectroscopy [6,7]with extraction processes, such as presoaking, liquid ammonia pretreatment, and others [8][9][10]. Among them, the UHPLC method has displayed its advantages such as simple operation, and high speed and sensitivity [11].…”