Unravelling the effect of pretreatment severity on the balance of cellulose accessibility and substrate composition on enzymatic digestibility of steam-pretreated softwood

2018 ◽  
Vol 109 ◽  
pp. 284-290 ◽  
Author(s):  
J.J. MacAskill ◽  
I.D. Suckling ◽  
J.A. Lloyd ◽  
M. Manley-Harris
Keyword(s):  
Enzymatic Digestibility ◽  
Substrate Composition ◽  
Cellulose Accessibility ◽  
Pretreatment Severity

scholarly journals Enhanced Saccharification of Purple Alfalfa via Sequential Pretreatment with Acidified Ethylene Glycol and Urea/NaOH

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Bo Fan ◽  
Lin Zhang ◽  
Zhengyu Tang ◽  
Liang Chen ◽  
Yu-Cai He
Keyword(s):  
Ethylene Glycol ◽  
Significant Influence ◽  
Potential Application ◽  
Reducing Sugars ◽  
High Potential ◽  
Lignocellulosic Material ◽  
Enzymatic Digestibility ◽  
Cellulose Accessibility ◽  
Hemicellulose Removal ◽  
High Yields

Purple Alfalfa is an inexpensive, abundant, readily available lignocellulosic material. This work was attempted to develop an efficient combination pretreatment by sequential HClO4–ethyl glycol–H2O (1.2:88.8:10, w/w/w) extraction at 130 °C in 0.5 h and urea/NaOH (urea 12 wt%, NaOH 7 wt%) soaking at −20 °C for 0.5 h for the pretreatment of purple alfalfa. The porosity, morphology, and crystallinity of pretreated purple alfalfa were characterized with SEM, FM, XRD, and FTIR. This combination pretreatment had a significant influence on hemicellulose removal and delignification. The above changes could enhance cellulose accessibility to enzymes and improve the enzymatic digestibility of cellulose. High yields of reducing sugars from pretreated purple alfalfa were obtained at 93.4%. In summary, this combination pretreatment has high potential application in the future.

Pseudo-Lignin Content Decreased with Hemicellulose and Lignin Removal, Improving Cellulose Accessibility, and Enzymatic Digestibility

2020 ◽  
Author(s):  
Alison Andrei Schmatz ◽  
Ana Maria Salazar-Bryam ◽  
Jonas Contiero ◽  
Celso Sant’Anna ◽  
Michel Brienzo
Keyword(s):  
Lignin Content ◽  
Enzymatic Digestibility ◽  
Lignin Removal ◽  
Cellulose Accessibility

Retention coefficients and thermal release profiles of ion-injected argon from silicates and iron

1970 ◽  
Vol 48 (12) ◽  
pp. 1472-1479
Author(s):  
Harry C. Lord III
Keyword(s):  
Volume Diffusion ◽  
Ion Irradiation ◽  
Defect Diffusion ◽  
Substrate Composition ◽  
Retention Coefficient ◽  
Thermal Release ◽  
Argon Concentration ◽  
Cold Rolled ◽  
Argon Ions ◽  
Release Profiles

Thermal release profiles and retention coefficients of injected argon ions were investigated as functions of substrate composition and prior ion-irradiation history. Samples of forsterite, enstatite, oligoclase, obsidian, and cold-rolled steel were irradiated with various sequences of 1 keV H+, 4 keV He+, and 40 keV Ar+. The release temperature of the maximum argon concentration was found to be a function of incident Ar+ dose and pre-irradiation history but not substrate composition. The hydrogen or helium pre-irradiation converted the volume diffusion argon release to a low temperature defect diffusion release. An increase in the incident dose of Ar+ ions resulted in increasing the percentage of the argon released by defect diffusion, and also decreased the argon retention coefficient.

scholarly journals Hydrothermal Pretreatment of Wheat Straw: Effects of Temperature and Acidity on Byproduct Formation and Inhibition of Enzymatic Hydrolysis and Ethanolic Fermentation

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 487
Author(s):  
Dimitrios Ilanidis ◽  
Stefan Stagge ◽  
Leif J. Jönsson ◽  
Carlos Martín
Keyword(s):  
Mass Spectrometry ◽  
Sulfuric Acid ◽  
Wheat Straw ◽  
High Performance ◽  
Enzymatic Saccharification ◽  
Hydrothermal Pretreatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzymatic Digestibility ◽  
Acid Catalyzed ◽  
Pretreatment Conditions

Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 °C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatography-electrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108–119% for autocatalyzed hydrothermal pretreatment at 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 °C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 °C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 °C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 °C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.

scholarly journals Effects on Lignin Redistribution in Eucalyptus globulus Fibres Pre-Treated by Steam Explosion: A Microscale Study to Cellulose Accessibility

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 507
Author(s):  
Eduardo Troncoso-Ortega ◽  
Rosario del P. Castillo ◽  
Pablo Reyes-Contreras ◽  
Patricia Castaño-Rivera ◽  
Regis Teixeira Mendonça ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Eucalyptus Globulus ◽  
Steam Explosion ◽  
Laser Scanning ◽  
Structural Changes ◽  
Micro Particles ◽  
Cellulose Accessibility ◽  
Ft Ir ◽  
Enzymatic Accessibility ◽  
Physical And Chemical

The objective of this study was to investigate structural changes and lignin redistribution in Eucalyptus globulus pre-treated by steam explosion under different degrees of severity (S0), in order to evaluate their effect on cellulose accessibility by enzymatic hydrolysis. Approximately 87.7% to 98.5% of original glucans were retained in the pre-treated material. Glucose yields after the enzymatic hydrolysis of pre-treated material improved from 19.4% to 85.1% when S0 was increased from 8.53 to 10.42. One of the main reasons for the increase in glucose yield was the redistribution of lignin as micro-particles were deposited on the surface and interior of the fibre cell wall. This information was confirmed by laser scanning confocal fluorescence and FT-IR imaging; these microscopic techniques show changes in the physical and chemical characteristics of pre-treated fibres. In addition, the results allowed the construction of an explanatory model for microscale understanding of the enzymatic accessibility mechanism in the pre-treated lignocellulose.

scholarly journals Conversion of Lignocellulosic Biomass to Nanocellulose: Structure and Chemical Process

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
H. V. Lee ◽  
S. B. A. Hamid ◽  
S. K. Zain
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Lignocellulosic Biomass ◽  
Chemical Process ◽  
Catalyst Design ◽  
Natural Resistance ◽  
Cellulose Crystallinity ◽  
Biomass Recalcitrance ◽  
Cellulose Accessibility ◽  
High Cellulose

Lignocellulosic biomass is a complex biopolymer that is primary composed of cellulose, hemicellulose, and lignin. The presence of cellulose in biomass is able to depolymerise into nanodimension biomaterial, with exceptional mechanical properties for biocomposites, pharmaceutical carriers, and electronic substrate’s application. However, the entangled biomass ultrastructure consists of inherent properties, such as strong lignin layers, low cellulose accessibility to chemicals, and high cellulose crystallinity, which inhibit the digestibility of the biomass for cellulose extraction. This situation offers both challenges and promises for the biomass biorefinery development to utilize the cellulose from lignocellulosic biomass. Thus, multistep biorefinery processes are necessary to ensure the deconstruction of noncellulosic content in lignocellulosic biomass, while maintaining cellulose product for further hydrolysis into nanocellulose material. In this review, we discuss the molecular structure basis for biomass recalcitrance, reengineering process of lignocellulosic biomass into nanocellulose via chemical, and novel catalytic approaches. Furthermore, review on catalyst design to overcome key barriers regarding the natural resistance of biomass will be presented herein.

The effect of substrate composition on the electrochemical and mechanical properties of PEO coatings on Mg alloys

2010 ◽  
Vol 204 (8) ◽  
pp. 1305-1313 ◽  
Author(s):  
Emrah Cakmak ◽  
Kadir C. Tekin ◽  
Ugur Malayoglu ◽  
Suman Shrestha
Keyword(s):  
Mechanical Properties ◽  
Mg Alloys ◽  
Substrate Composition ◽  
Peo Coatings
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