Enzymatic Hydrolysis of Switchgrass and Tall Wheatgrass Mixtures Using Dilute Sulfuric Acid and Aqueous Ammonia Pretreatments

2011 ◽  
Vol 3 (3) ◽  
pp. 163-171 ◽  
Author(s):  
B. Karki ◽  
N. Nahar ◽  
S. W. Pryor
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Aqueous Ammonia ◽  
Tall Wheatgrass ◽  
Dilute Sulfuric Acid ◽  
Hydrolysis Of

scholarly journals Effect of dilute sulfuric acid pretreatment on the physicochemical properties and enzymatic hydrolysis of coffee cut-stems

Energy ◽  
2020 ◽  
Vol 195 ◽  
pp. 116986 ◽  
Author(s):  
Juan Camilo Solarte-Toro ◽  
Yessica Chacón-Pérez ◽  
Sara Piedrahita-Rodríguez ◽  
Jhonny Alejandro Poveda Giraldo ◽  
José António Teixeira ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Physicochemical Properties ◽  
Acid Pretreatment ◽  
Dilute Sulfuric Acid ◽  
Dilute Sulfuric Acid Pretreatment ◽  
Sulfuric Acid Pretreatment ◽  
Hydrolysis Of

scholarly journals THF co-solvent pretreatment prevents lignin redeposition from interfering with enzymes yielding prolonged cellulase activity

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Abhishek S. Patri ◽  
Ramya Mohan ◽  
Yunqiao Pu ◽  
Chang G. Yoo ◽  
Arthur J. Ragauskas ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Cellulase Activity ◽  
Biofuel Production ◽  
Scanning Electron Micrographs ◽  
Enzyme Deactivation ◽  
Dilute Sulfuric Acid ◽  
Nmr Characterization ◽  
Hydrolysis Of

Abstract Background Conventional aqueous dilute sulfuric acid (DSA) pretreatment of lignocellulosic biomass facilitates hemicellulose solubilization and can improve subsequent enzymatic digestibility of cellulose to fermentable glucose. However, much of the lignin after DSA pretreatment either remains intact within the cell wall or readily redeposits back onto the biomass surface. This redeposited lignin has been shown to reduce enzyme activity and contribute to rapid enzyme deactivation, thus, necessitating significantly higher enzyme loadings than deemed economical for biofuel production from biomass. Results In this study, we demonstrate how detrimental lignin redeposition on biomass surface after pretreatment can be prevented by employing Co-solvent Enhanced Lignocellulosic Fractionation (CELF) pretreatment that uses THF–water co-solvents with dilute sulfuric acid to solubilize lignin and overcome limitations of DSA pretreatment. We first find that enzymatic hydrolysis of CELF-pretreated switchgrass can sustain a high enzyme activity over incubation periods as long as 5 weeks with enzyme doses as low as 2 mg protein/g glucan to achieve 90% yield to glucose. A modified Ninhydrin-based protein assay revealed that the free-enzyme concentration in the hydrolysate liquor, related to enzyme activity, remained unchanged over long hydrolysis times. DSA-pretreated switchgrass, by contrast, had a 40% drop in free enzymes in solution during incubation, providing evidence of enzyme deactivation. Furthermore, measurements of enzyme adsorption per gram of lignin suggested that CELF prevented lignin redeposition onto the biomass surface, and the little lignin left in the solids was mostly integral to the original lignin–carbohydrate complex (LCC). Scanning electron micrographs and NMR characterization of lignin supported this observation. Conclusions Enzymatic hydrolysis of solids from CELF pretreatment of switchgrass at low enzyme loadings was sustained for considerably longer times and reached higher conversions than for DSA solids. Analysis of solids following pretreatment and enzymatic hydrolysis showed that prolonged cellulase activity could be attributed to the limited lignin redeposition on the biomass surface making more enzymes available for hydrolysis of more accessible glucan.

Enzymatic Hydrolysis of Corn Stover after Pretreatment with Dilute Sulfuric Acid

2007 ◽  
Vol 30 (7) ◽  
pp. 938-944 ◽  
Author(s):  
X. B. Lu ◽  
Y. M. Zhang ◽  
J. Yang ◽  
Y. Liang
Keyword(s):  
Sulfuric Acid ◽  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Dilute Sulfuric Acid ◽  
Hydrolysis Of

Improving the efficiency of enzymatic hydrolysis of Eucalyptus residues with a modified aqueous ammonia soaking method

2018 ◽  
Vol 33 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Dan Huo ◽  
Qiulin Yang ◽  
Guigan Fang ◽  
Qiujuan Liu ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Enzymatic Hydrolysis ◽  
Aqueous Ammonia ◽  
Pulp Mill ◽  
Fiber Surface ◽  
Raw Material ◽  
Sem Images ◽  
Aqueous Ammonia Soaking ◽  
Guaiacyl Lignin ◽  
Hydrolysis Of

Abstract Eucalyptus residues from pulp mill were pretreated with aqueous ammonia soaking (AAS) method to improve the efficiency of enzymatic hydrolysis. The optimized condition of AAS was obtained by response surface methodology. Meanwhile, hydrogen peroxide was introduced into the AAS system to modify the AAS pretreatment (AASP). The results showed that a fermentable sugar yield of 64.96 % was obtained when the eucalypt fibers were pretreated at the optimal conditions, with 80 % of ammonia (w/w) for 11 h and keeping the temperature at 90 °C. In further research it was found that the addition of H2O2 to the AAS could improve the pretreatment efficiency. The delignification rate and enzymatic digestibility were increased to 64.49 % and 73.85 %, respectively, with 5 % of hydrogen peroxide being used. FTIR analysis indicated that most syringyl and guaiacyl lignin and a trace amount of xylan were degraded and dissolved during the AAS and AASP pretreatments. The CrI of the raw material was increased after AAS and AASP pretreatments, which was attributed to the removal of amorphous portion. SEM images showed that microfibers were separated and explored from the initial fiber structure after AAS pretreatment, and the AASP method could improve the destructiveness of the fiber surface.

Stepwise pretreatment of aqueous ammonia and ethylenediamine improve enzymatic hydrolysis of corn stover

2018 ◽  
Vol 124 ◽  
pp. 201-208 ◽  
Author(s):  
Jia-Qing Zhu ◽  
Wen-Chao Li ◽  
Lei Qin ◽  
Xiong Zhao ◽  
Si Chen ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Aqueous Ammonia ◽  
Hydrolysis Of

scholarly journals Two-stage, dilute sulfuric acid hydrolysis of wood : an investigation of fundamentals

1985 ◽  
Author(s):  
John F. Harris ◽  
Andrew J. Baker ◽  
Anthony H. Conner ◽  
Thomas W. Jeffries ◽  
James L. Minor ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Hydrolysis ◽  
Two Stage ◽  
Dilute Sulfuric Acid ◽  
Hydrolysis Of
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