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Maati J, Prazeres DM, Grąz M, Wiater A, Jarosz-Wilkołazka A, Smaali I. Heteroxylan hydrolysis by a recombinant cellulase-free GH10 xylanase from the alkaliphilic bacterium Halalkalibacterium halodurans C-125. Arch Microbiol 2024; 206:261. [PMID: 38753095 DOI: 10.1007/s00203-024-03982-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 04/13/2024] [Accepted: 04/25/2024] [Indexed: 06/18/2024]
Abstract
The search for affordable enzymes with exceptional characteristics is fundamental to overcoming industrial and environmental constraints. In this study, a recombinant GH10 xylanase (Xyn10-HB) from the extremely alkaliphilic bacterium Halalkalibacterium halodurans C-125 cultivated at pH 10 was cloned and expressed in E. coli BL21(DE3). Removal of the signal peptide improved the expression, and an overall activity of 8 U/mL was obtained in the cell-free supernatant. The molecular weight of purified Xyn10-HB was estimated to be 42.6 kDa by SDS-PAGE. The enzyme was active across a wide pH range (5-10) with optimal activity recorded at pH 8.5 and 60 °C. It also presented good stability with a half-life of 3 h under these conditions. Substrate specificity studies showed that Xyn10-HB is a cellulase-free enzyme that conventionally hydrolyse birchwood and oat spelts xylans (Apparent Km of 0.46 mg/mL and 0.54 mg/mL, respectively). HPLC analysis showed that both xylans hydrolysis produced xylooligosaccharides (XOS) with a degree of polymerization (DP) ranging from 2 to 9. The conversion yield was 77% after 24 h with xylobiose and xylotriose as the main end-reaction products. When assayed on alkali-extracted wheat straw heteroxylan, the Xyn10-HB produced active XOS with antioxidant activity determined by the DPPH radical scavenging method (IC50 of 0.54 mg/mL after 4 h). Owing to its various characteristics, Xyn10-HB xylanase is a promising candidate for multiple biotechnological applications.
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Affiliation(s)
- Jihene Maati
- University of Carthage, Laboratory of Protein Engineering and Bioactive Molecules (LIP-MB-LR11ES24), INSAT-BP 676, 1080, Tunis Cedex, Tunisia
| | - Duarte Miguel Prazeres
- Institute for Bioengineering and Biosciences-iBB, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisbon, Portugal
- Institute for Health and Bioeconomy-li4HB, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisbon, Portugal
| | - Marcin Grąz
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Adrian Wiater
- Department of Industrial and Environmental Microbiology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Anna Jarosz-Wilkołazka
- Department of Biochemistry and Biotechnology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Issam Smaali
- University of Carthage, Laboratory of Protein Engineering and Bioactive Molecules (LIP-MB-LR11ES24), INSAT-BP 676, 1080, Tunis Cedex, Tunisia.
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Liao H, Xu Y, Sun FF, Zhang J. Optimizing tri-acid mixture hydrolysis: An improved strategy for efficient xylooligosaccharides production from corncob. BIORESOURCE TECHNOLOGY 2023; 369:128500. [PMID: 36535614 DOI: 10.1016/j.biortech.2022.128500] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
Propionic acid (PA) hydrolysis of corncob for xylooligosaccharides (XOS) production has the advantages of simple operation, high XOS yield and less by-products, but the high price of PA limits its application. Therefore, partially replacing PA with less expensive organic acids, such as formic acid (FA) and acetic acid (AC), may lower the cost of hydrolysis in XOS production. This work investigated the feasibility of XOS production from corncob using a tri-acid mixture of FA, AC and PA. A high XOS yield of 69.1 % was achieved under the optimal FA:PA:AC volume ratio of 1:5:4 at 150 °C for 50 min. Overall, in the XOS production from corncob, it was able to replace 60 % of PA with FA and AC, and decreased the hydrolysis temperature from 170 °C to 150 °C, all of which were important to lower the cost of XOS production using organic acid hydrolysis.
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Affiliation(s)
- Hong Liao
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, China
| | - Yong Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, China
| | - Fubao Fuelbiol Sun
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Junhua Zhang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, China.
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Sürmeli Y, Şanlı-Mohamed G. Engineering of xylanases for the development of biotechnologically important characteristics. Biotechnol Bioeng 2023; 120:1171-1188. [PMID: 36715367 DOI: 10.1002/bit.28339] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/19/2022] [Accepted: 01/26/2023] [Indexed: 01/31/2023]
Abstract
Xylanases are the main biocatalysts used for the reduction of the xylan backbone from hemicellulose, randomly splitting off β-1,4-glycosidic linkages between xylopyranosyl residues. Xylanase market has been annually estimated at 500 million US Dollars and they are potentially used in broad industrial process ranges such as paper pulp biobleaching, xylo-oligosaccharide production, and biofuel manufacture from lignocellulose. The highly stable xylanases are preferred in the downstream procedure of industrial processes because they can tolerate severe conditions. Almost all native xylanases can not endure adverse conditions thus they are industrially not proper to be utilized. Protein engineering is a powerful technology for developing xylanases, which can effectively work in adverse conditions and can meet requirements for industrial processes. This study considered state-of-the-art strategies of protein engineering for creating the xylanase gene diversity, high-throughput screening systems toward upgraded traits of the xylanases, and the prediction and comprehensive analysis of the target mutations in xylanases by in silico methods. Also, key molecular factors have been elucidated for industrial characteristics (alkaliphilic enhancement, thermal stability, and catalytic performance) of GH11 family xylanases. The present review explores industrial characteristics improved by directed evolution, rational design, and semi-rational design as protein engineering approaches for pulp bleaching process, xylooligosaccharides production, and biorefinery & bioenergy production.
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Affiliation(s)
- Yusuf Sürmeli
- Department of Agricultural Biotechnology, Tekirdağ Namık Kemal University, Tekirdağ, Turkey
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Kinetic Model for Enzymatic Hydrolysis of Cellulose from Pre-Treated Rice Husks. FERMENTATION 2022. [DOI: 10.3390/fermentation8090417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Rice husks contain cellulose as a raw material for manufacturing second-generation bioethanol. Cellulose from pre-treated rice husks was converted into reducing sugars through enzymatic hydrolysis using enzymes derived from Aspergillus niger. This study aims to determine the kinetics of enzymatic hydrolysis at enzyme concentrations of 10, 15, and 20% (v/w) and hydrolysis times of 5, 10, 15, 20, and 25 h. The results showed that cellulose was hydrolyzed to form reducing sugars. The CMCase activity and FPase activity reached 548.940 and 314.892 U mL−1, respectively, much higher than most previous reports on this genus. From the calculation of the reaction rate using the Michaelis–Menten kinetic model, the value of the Michaelis constant ranges from 0.001 to 0.0007, and the maximum rate is 1.3 × 10−7 to 2.7 × 10−7 Mol L−1 s−1. The highest reducing sugar concentration was obtained (1.80 g L−1) at an enzyme concentration of 20% (v/w) and a hydrolysis time of 25 h.
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Lin CY, Donohoe BS, Bomble YJ, Yang H, Yunes M, Sarai NS, Shollenberger T, Decker SR, Chen X, McCann MC, Tucker MP, Wei H, Himmel ME. Iron incorporation both intra- and extra-cellularly improves the yield and saccharification of switchgrass (Panicum virgatum L.) biomass. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:55. [PMID: 33663584 PMCID: PMC7931346 DOI: 10.1186/s13068-021-01891-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Pretreatments are commonly used to facilitate the deconstruction of lignocellulosic biomass to its component sugars and aromatics. Previously, we showed that iron ions can be used as co-catalysts to reduce the severity of dilute acid pretreatment of biomass. Transgenic iron-accumulating Arabidopsis and rice plants exhibited higher iron content in grains, increased biomass yield, and importantly, enhanced sugar release from the biomass. RESULTS In this study, we used intracellular ferritin (FerIN) alone and in combination with an improved version of cell wall-bound carbohydrate-binding module fused iron-binding peptide (IBPex) specifically targeting switchgrass, a bioenergy crop species. The FerIN switchgrass improved by 15% in height and 65% in yield, whereas the FerIN/IBPex transgenics showed enhancement up to 30% in height and 115% in yield. The FerIN and FerIN/IBPex switchgrass had 27% and 51% higher in planta iron accumulation than the empty vector (EV) control, respectively, under normal growth conditions. Improved pretreatability was observed in FerIN switchgrass (~ 14% more glucose release than the EV), and the FerIN/IBPex plants showed further enhancement in glucose release up to 24%. CONCLUSIONS We conclude that this iron-accumulating strategy can be transferred from model plants and applied to bioenergy crops, such as switchgrass. The intra- and extra-cellular iron incorporation approach improves biomass pretreatability and digestibility, providing upgraded feedstocks for the production of biofuels and bioproducts.
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Affiliation(s)
- Chien-Yuan Lin
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Emeryville, CA 94608 USA
- Present Address: Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Yannick J. Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Haibing Yang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 USA
- Present Address: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Manal Yunes
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Nicholas S. Sarai
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- Present Address: Division of Chemistry and Chemical Engineering 210-41, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 USA
| | - Todd Shollenberger
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Stephen R. Decker
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Xiaowen Chen
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Maureen C. McCann
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 USA
| | - Melvin P. Tucker
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Hui Wei
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
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Li Q, Jiang Y, Tong X, Zhao L, Pei J. Co-production of Xylooligosaccharides and Xylose From Poplar Sawdust by Recombinant Endo-1,4-β-Xylanase and β-Xylosidase Mixture Hydrolysis. Front Bioeng Biotechnol 2021; 8:637397. [PMID: 33598452 PMCID: PMC7882696 DOI: 10.3389/fbioe.2020.637397] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 12/21/2020] [Indexed: 11/29/2022] Open
Abstract
As is well-known, endo-1,4-β-xylanase and β-xylosidase are the rate-limiting enzymes in the degradation of xylan (the major hemicellulosic component), main functions of which are cleavaging xylan to release xylooligosaccharides (XOS) and xylose that these two compounds have important application value in fuel, food, and other industries. This study focuses on enzymatic hydrolysis of poplar sawdust xylan for production of XOS and xylose by a GH11 endo-1,4-β-xylanase MxynB-8 and a GH39 β-xylosidase Xln-DT. MxynB-8 showed excellent ability to hydrolyze hemicellulose of broadleaf plants, such as poplar. Under optimized conditions (50°C, pH 6.0, dosage of 500 U/g, substrate concentration of 2 mg/mL), the final XOS yield was 85.5%, and the content of XOS2−3 reached 93.9% after 18 h. The enzymatic efficiency by MxynB-8 based on the poplar sawdust xylan in the raw material was 30.5%. Xln-DT showed excellent xylose/glucose/arabinose tolerance, which is applied as a candidate to apply in degradation of hemicellulose. In addition, the process and enzymatic mode of poplar sawdust xylan with MxynB-8 and Xln-DT were investigated. The results showed that the enzymatic hydrolysis yield of poplar sawdust xylan was improved by adding Xln-DT, and a xylose-rich hydrolysate could be obtained at high purity, with the xylose yield of 89.9%. The enzymatic hydrolysis yield was higher (32.2%) by using MxynB-8 and Xln-DT together. This study provides a deep understanding of double-enzyme synergetic enzymolysis of wood polysaccharides to valuable products.
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Affiliation(s)
- Qi Li
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Products, Nanjing Forestry University, Nanjing, China.,College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
| | - Yunpeng Jiang
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
| | - Xinyi Tong
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
| | - Linguo Zhao
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Co-innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jianjun Pei
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Products, Nanjing Forestry University, Nanjing, China.,College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
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Environmentally Friendly Approach for the Production of Glucose and High-Purity Xylooligosaccharides from Edible Biomass Byproducts. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10228119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Xylooligosaccharides (XOS) production from sweet sorghum bagasse (SSB) has been barely studied using other edible biomasses. Therefore, we evaluated the XOS content as well as its purity by comparing the content of total sugars from SSB. An environmentally friendly approach involving autohydrolysis was employed, and the reaction temperature and time had variations in order to search for the conditions that would yield high-purity XOS. After autohydrolysis, the remaining solid residues, the glucan-rich fraction, were used as substrates to be enzymatically hydrolyzed for glucose conversion. The highest XOS was observed for total sugars (68.7%) at 190 °C for 5 min among the autohydrolysis conditions. However, we also suggested two alternative conditions, 180 °C for 20 min and 190 °C for 15 min, because the former condition might have the XOS at a low degree of polymerization with a high XOS ratio (67.6%), while the latter condition presented a high glucose to total sugar ratio (91.4%) with a moderate level XOS ratio (64.4%). Although it was challenging to conclude on the autohydrolysis conditions required to obtain the best result of XOS content and purity and glucose yield, this study presented approaches that could maximize the desired product from SSB, and additional processes to reduce these differences in conditions may warrant further research.
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Igbojionu LI, Laluce C, Silva JP, Silva JL. Optimization of FeSO4-Assisted Sulfuric Acid Hydrolysis for Improved Sugar Yield from Sugarcane Bagasse. Ind Biotechnol (New Rochelle N Y) 2020. [DOI: 10.1089/ind.2020.0020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Longinus Ifeanyi Igbojionu
- Bioenergy Research Institute, Institute of Chemistry, São Paulo State University Araraquara, São Paulo, Brazil
| | - Cecilia Laluce
- Bioenergy Research Institute, Institute of Chemistry, São Paulo State University Araraquara, São Paulo, Brazil
| | - João Pedro Silva
- Department of Analytical Chemistry, Institute of Chemistry, São Paulo State University Araraquara, São Paulo, Brazil
| | - José Luiz Silva
- Bioenergy Research Institute, Institute of Chemistry, São Paulo State University Araraquara, São Paulo, Brazil
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Di Fidio N, Antonetti C, Raspolli Galletti AM. Microwave-assisted cascade exploitation of giant reed (Arundo donax L.) to xylose and levulinic acid catalysed by ferric chloride. BIORESOURCE TECHNOLOGY 2019; 293:122050. [PMID: 31454732 DOI: 10.1016/j.biortech.2019.122050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/17/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
The present work aimed to investigate and optimize the selective exploitation of hemicellulose and cellulose fractions of the energy crop Arundo donax L. (giant reed), to give xylose and levulinic acid, respectively. In order to improve the sustainability of this process, a microwave-assisted hydrolysis in the presence of FeCl3 was implemented using as substrate the raw biomass without any pretreatment process. The effects of the hydrolysis reaction conditions, such as temperature, reaction time, salt amount and biomass loading, on giant reed exploitation were investigated. In the first step, under the optimized conditions (150 °C, 2.5 min and 1.6 wt% FeCl3), the xylose yield reached 98.2 mol%. In the second step, under the best conditions (190 °C, 30 min and 2.4 wt% FeCl3), the levulinic acid yield was 57.6 mol%. This novel cascade approach ensured an extensive exploitation of giant reed polysaccharides working in the respect of Green Chemistry principles.
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Affiliation(s)
- Nicola Di Fidio
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Claudia Antonetti
- Department of Chemistry and Industrial Chemistry, University of Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
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Effect of Dilute Acid and Alkali Pretreatments on the Catalytic Performance of Bamboo-Derived Carbonaceous Magnetic Solid Acid. Catalysts 2019. [DOI: 10.3390/catal9030245] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lignocellulose is a widely used renewable energy source on the Earth that is rich in carbon skeletons. The catalytic hydrolysis of lignocellulose over magnetic solid acid is an efficient pathway for the conversion of biomass into fuels and chemicals. In this study, a bamboo-derived carbonaceous magnetic solid acid catalyst was synthesized by FeCl3 impregnation, followed by carbonization and –SO3H group functionalization. The prepared catalyst was further subjected as the solid acid catalyst for the catalytic conversion of corncob polysaccharides into reducing sugars. The results showed that the as-prepared magnetic solid acid contained –SO3H, –COOH, and polycyclic aromatic, and presented good catalytic performance for the hydrolysis of corncob in the aqueous phase. The concentration of H+ was in the range of 0.6487 to 2.3204 mmol/g. Dilute acid and alkali pretreatments of raw material can greatly improve the catalytic activity of bamboo-derived carbonaceous magnetic solid acid. Using the catalyst prepared by 0.25% H2SO4-pretreated bamboo, 6417.5 mg/L of reducing sugars corresponding to 37.17% carbohydrates conversion could be obtained under the reaction conditions of 120 °C for 30 min.
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Recent progress in homogeneous Lewis acid catalysts for the transformation of hemicellulose and cellulose into valuable chemicals, fuels, and nanocellulose. REV CHEM ENG 2018. [DOI: 10.1515/revce-2017-0071] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Abstract
The evolution from petroleum-based products to the bio-based era by using renewable resources is one of the main research challenges in the coming years. Lignocellulosic biomass, consisting of inedible plant material, has emerged as a potential alternative for the production of biofuels, biochemicals, and nanocellulose-based advanced materials. The lignocellulosic biomass, which consists mainly of carbohydrate-based polysaccharides (hemicellulose and cellulose), is a green intermediate for the synthesis of bio-based products. In recent years, the re-engineering of biomass into a variety of commodity chemicals and liquid fuels by using Lewis acid catalysts has attracted much attention. Much research has been focused on developing new chemical strategies for the valorization of different biomass components. Homogeneous Lewis acid catalysts seem to be one of the most promising catalysts due to their astonishing features such as being less corrosive to equipment and being friendlier to the environment, as well as having the ability to disrupt the bonding system effectively and having high selectivity. Thus, these catalysts have emerged as important tools for the highly selective transformation of biomass components into valuable chemicals and fuels. This review provides an insightful overview of the most important recent developments in homogeneous Lewis acid catalysis toward the production and upgrading of biomass. The chemical valorization of the main components of lignocellulosic biomass (hemicellulose and cellulose), the reaction conditions, and process mechanisms are reviewed.
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