Calcium peroxide pretreatment to facilitate the delignification and enzymatic hydrolysis of wheat straw

Abstract Calcium peroxide (CaO2) pretreatment was employed to remove lignin and subsequently facilitate enzymatic digestibility of wheat straw. An optimal condition was obtained at 130°C for 10 min with 0.35 g CaO2/g dried material of wheat straw and a 1:8 solid-liquid ratio. Under this condition, 57.8% of initial lignin, 7.2% of initial glucan, and 30.6% of initial xylan were removed from CaO2 pretreatment, respectively, meanwhile, a glucose recovery of 90.6 % and a xylose recovery of 65.9 % were obtained from the subsequent enzymatic hydrolysis of treated wheat straw, respectively. CaO2 pretreatment was proved to be a very effective method in delignification and improving enzymatic digestibility. Compared to raw material, the complex structure of lignocellulose was drastically disrupted with a wide emergence of scaly bulges and fully exposed microfibers, which still retained in the solid.

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Production of Cellulosic Ethanol from Enzymatically Hydrolysed Wheat Straws

Applied Sciences ◽

10.3390/app10217638 ◽

2020 ◽

Vol 10 (21) ◽

pp. 7638

Author(s):

Vasile-Florin Ursachi ◽

Gheorghe Gutt

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Cellulosic Ethanol ◽

Raw Material ◽

High Yield ◽

Liquid Ratio ◽

Hydrolysis Process ◽

Pretreatment Conditions ◽

Pretreated Wheat Straw ◽

First Time

The aim of this study is to find the optimal pretreatment conditions and hydrolysis in order to obtain a high yield of bioethanol from wheat straw. The pretreatments were performed with different concentrations of sulphuric acid 1, 2 and 3% (v/v), and were followed by an enzymatic hydrolysis that was performed by varying the solid-to-liquid ratio (1/20, 1/25 and 1/30 g/mL) and the enzyme dose (30/30 µL/g, 60/60 µL/g and 90/90 µL/g Viscozyme® L/Celluclast® 1.5 L). This mix of enzymes was used for the first time in the hydrolysis process of wheat straws which was previously pretreated with dilute sulfuric acid. Scanning electron microscopy indicated significant differences in the structural composition of the samples because of the pretreatment with H2SO4 at different concentrations, and ATR-FTIR analysis highlighted the changes in the chemical composition in the pretreated wheat straw as compared to the untreated one. HPLC-RID was used to identify and quantify the carbohydrates content resulted from enzymatic hydrolysis to evaluate the potential of using wheat straws as a raw material for production of cellulosic ethanol in Romania. The highest degradation of lignocellulosic material was obtained in the case of pretreatment with 3% H2SO4 (v/v), a solid-to-liquid ratio of 1/30 and an enzyme dose of 90/90 µL/g. Simultaneous saccharification and fermentation were performed using Saccharomyces cerevisiae yeast, and for monitoring the fermentation process a BlueSens equipment was used provided with ethanol, O2 and CO2 cap sensors mounted on the fermentation flasks. The highest concentration of bioethanol was obtained after 48 h of fermentation and it reached 1.20% (v/v).

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A New and Environmentally Friendly Route for Preparation of Carbon Microspheres from Wheat Straw

The Scientific World JOURNAL ◽

10.1155/2013/146930 ◽

2013 ◽

Vol 2013 ◽

pp. 1-3 ◽

Cited By ~ 1

Author(s):

Chen Leishan ◽

Wang Cunjing ◽

Miao Yu ◽

Chen Gairong

Keyword(s):

Fourier Transform ◽

Electron Microscope ◽

Wheat Straw ◽

Carbon Materials ◽

Hydrothermal Carbonization ◽

Raw Material ◽

Carbon Microspheres ◽

Liquid Ratio ◽

Solid Liquid ◽

Scanning Electron

The reactions were performed to synthesize carbon materials using wheat straw powder as raw material. The wheat straw powder was first hydrolyzed at the absence of a catalyst at 190°C for 1 h, then the hydrolyzate solution was used as carbon source to prepare carbon materials via hydrothermal carbonization at 180°C in the absence of a catalyst for 8 h. The influence of solid-liquid-ratio of wheat straw to water on the morphology of the product was investigated. The samples were examined by a scanning electron microscope and Fourier transform infrared spectroscopy. The results show that the product was carbon microspheres with a large number of O–H, CHO, and other functional groups, and the diameters of carbon microspheres noticeably depended on the solid-liquid ratio. When the solid-liquid ratio was 1 : 60, the diameters of carbon microspheres were in the range of 100 to 300 nm when the solid-liquid ratio was 1 : 40, carbon microspheres with larger and more uniform diameters mostly about 250 nm were obtained, and when the solid-liquid-ratio was 1 : 20, there were more larger carbon microspheres with diameters about 800 nm in the product and the surface of these carbon microspheres is smoother, whereas; the uniformity of the product deteriorates.

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Effects of the Protein in Wheat Straw on Enzymatic Hydrolysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1198 ◽

2013 ◽

Vol 690-693 ◽

pp. 1198-1202 ◽

Cited By ~ 1

Author(s):

Hui Chen ◽

Lian Jie Wang ◽

Tao Zhang ◽

Meng Yu ◽

Xin Ming Wang

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Degradation Rate ◽

Cellulose Degradation ◽

Hydrolysis Time ◽

Reaction Conditions ◽

Orthogonal Experiments ◽

Enzyme Dosage ◽

Solid Liquid ◽

Hydrolysis Of

The article used acid protease to remove the protein in wheat straw, and investigated the influence of wheat straw without the protein to enzymatic hydrolysis. By the single factor experiments, the cellulose degradation rate of wheat straw removed the protein was significantly higher than untreated, in the same conditions of enzymatic hydrolysis. It is shortening 24h of enzymatic hydrolysis time and reducing enzyme dosage 90mg/g. By the orthogonal experiments, the optimal reaction conditions for enzymatic hydrolysis of wheat straw with protein removed is the cellulase dosage 170mg, enzymatic time 56h, solid-liquid ratio 1:20, pH 4.8, the reaction temperature 50°C. Compared to the untreated, the cellulose degradation rate increased by 35.58%.

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Properties important for solid–liquid separations change during the enzymatic hydrolysis of pretreated wheat straw

Biotechnology Letters ◽

10.1007/s10529-018-2521-8 ◽

2018 ◽

Vol 40 (4) ◽

pp. 703-709 ◽

Cited By ~ 3

Author(s):

Noah D. Weiss ◽

Claus Felby ◽

Lisbeth G. Thygesen

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Pretreated Wheat Straw ◽

Solid Liquid ◽

Liquid Separations ◽

Hydrolysis Of

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The influence of solid/liquid separation techniques on the sugar yield in two-step dilute acid hydrolysis of softwood followed by enzymatic hydrolysis

Biotechnology for Biofuels ◽

10.1186/1754-6834-2-6 ◽

2009 ◽

Vol 2 (1) ◽

pp. 6 ◽

Cited By ~ 29

Author(s):

Sanam Monavari ◽

Mats Galbe ◽

Guido Zacchi

Keyword(s):

Enzymatic Hydrolysis ◽

Acid Hydrolysis ◽

Sugar Yield ◽

Dilute Acid ◽

Dilute Acid Hydrolysis ◽

Liquid Separation ◽

Separation Techniques ◽

Solid Liquid ◽

Solid Liquid Separation ◽

Hydrolysis Of

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

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2018-3025 ◽

2018 ◽

Vol 33 (2) ◽

pp. 165-174 ◽

Cited By ~ 2

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.

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Kinetic model of enzymatic hydrolysis of steam-exploded wheat straw

Carbohydrate Polymers ◽

10.1016/j.carbpol.2011.09.012 ◽

2012 ◽

Vol 87 (2) ◽

pp. 1280-1285 ◽

Cited By ~ 13

Author(s):

Greta Radeva ◽

Ivo Valchev ◽

Stoiko Petrin ◽

Eva Valcheva ◽

Petya Tsekova

Keyword(s):

Enzymatic Hydrolysis ◽

Kinetic Model ◽

Wheat Straw ◽

Hydrolysis Of

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Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood

Holzforschung ◽

10.1515/hf.2011.066 ◽

2011 ◽

Vol 65 (4) ◽

Cited By ~ 21

Author(s):

Fokko Schütt ◽

Jürgen Puls ◽

Bodo Saake

Keyword(s):

Enzymatic Hydrolysis ◽

Raw Material ◽

Steam Pretreatment ◽

Alkaline Extraction ◽

Poplar Wood ◽

Steam Refining ◽

Severity Factor ◽

Short Rotation ◽

Pretreatment Conditions ◽

Hydrolysis Of

Abstract Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.

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Investigation of interaction between cellulase and residual lignin fractions in acid-pretreated bamboo residues and their effect on enzymatic digestibility

10.21203/rs.3.rs-371092/v1 ◽

2021 ◽

Author(s):

Wenqian Lin ◽

Jinlai Yang ◽

Yayue Zheng ◽

Caoxing Huang ◽

Qiang Yong

Keyword(s):

Enzymatic Hydrolysis ◽

Negative Impact ◽

Interaction Mechanism ◽

Dilute Acid Pretreatment ◽

Affinity Constant ◽

Residual Lignin ◽

Dilute Acid ◽

Enzymatic Digestibility ◽

Acid Pretreatment ◽

Hydrolysis Of

Abstract Background: During dilute acid pretreatment, pseudo lignin and lignin form droplets which deposit on the surface of lignocellulose, and further inhibit its enzymatic hydrolysis. However, how this lignin interacts with cellulase enzymes and then affects enzymatic hydrolysis is still unknown. In this work, different fractions of surface lignin (SL) obtained from dilute acid pretreated bamboo residues (DAP-BR) were extracted by various organic reagents and the residual lignin in extracted DAP-BR was obtained by milled wood lignin (MWL) method. All the obtained lignin fractions from DAP-BR were used to investigate the interaction mechanism between lignin and cellulase using surface plasmon resonance (SPR) technology in order to understand how they affect enzymatic hydrolysisResults: Results showed that removing surface lignin significantly decrease the enzymatic hydrolysis of DAP-BR from 36.5% to 18.6%. The addition of MWL samples to Avicel decreased enzymatic hydrolysis of Avicel, while different SL samples showed a slight increase to its enzymatic digestibility. Due to the higher molecular weight and hydrophobicity of MWL samples versus the SL samples, stronger affinity for MWL (KD = 6.8-24.7 nM) was found versus that of SL (KD = 39.4-52.6 nM) by SPR analysis. The affinity constant of all tested lignin had good correlations (R2>0.6) with their effects on enzymatic digestibility of extracted DAP-BR and Avicel.Conclusions: This work reveals that the surface lignin on DAP-BR is necessary towards maintaining enzyme digestibility levels, and its removal has a negative impact on the substrate’s digestibility.

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