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Chandrasekar M, Collins JL, Habibi S, Ong RG. Microfluidic reactor designed for time-lapsed imaging of pretreatment and enzymatic hydrolysis of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2024; 393:129989. [PMID: 37931765 DOI: 10.1016/j.biortech.2023.129989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 11/08/2023]
Abstract
The effect of tissue-specific biochemical heterogeneities of lignocellulosic biomass on biomass deconstruction is best understood through confocal laser scanning microscopy (CLSM) combined with immunohistochemistry. However, this process can be challenging, given the fragility of plant materials, and is generally not able to observe changes in the same section of biomass during both pretreatment and enzymatic hydrolysis. To overcome this challenge, a custom polydimethylsiloxane (PDMS) microfluidic imaging reactor was constructed using standard photolithographic techniques. As proof of concept, CLSM was performed on 60 μm-thick corn stem sections during pretreatment and enzymatic hydrolysis using the imaging reactor. Based on the fluorescence images, the less lignified parenchyma cell walls were more susceptible to pretreatment than the lignin-rich vascular bundles. During enzymatic hydrolysis, the highly lignified protoxylem cell wall was the most resistant, remaining unhydrolyzed even after 48 h. Therefore, imaging thin whole biomass sections was useful to obtain tissue-specific changes during biomass deconstruction.
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Affiliation(s)
- Meenaa Chandrasekar
- Department of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, 49931, MI, USA; DOE Great Lakes Bioenergy Research Center, Michigan Technological University, 1400 Townsend Drive, Houghton, 49931, MI, USA
| | - Jeana L Collins
- Department of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, 49931, MI, USA
| | - Sanaz Habibi
- Department of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, 49931, MI, USA
| | - Rebecca G Ong
- Department of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, 49931, MI, USA; DOE Great Lakes Bioenergy Research Center, Michigan Technological University, 1400 Townsend Drive, Houghton, 49931, MI, USA.
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2
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Wang G, Huang M, Li F, Li Q, Chen F, Wang S, Ling Z, Ji Z. Insights into the poplar cell wall deconstruction following deep eutectic solvent pretreatment for enhanced enzymatic saccharification and lignin valorization. Int J Biol Macromol 2024; 254:127673. [PMID: 38287581 DOI: 10.1016/j.ijbiomac.2023.127673] [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: 08/23/2023] [Revised: 10/17/2023] [Accepted: 10/23/2023] [Indexed: 01/31/2024]
Abstract
In this study, a combination of microcosmic and chemical analysis methods was used to investigate deep eutectic solvent (DES) pretreatment effects on cell wall's micromorphology and lignin's dissolution regular, in order to achieve high-performance biorefinery. The atomic force microscope observed that DES pretreatment peeled off non-cellulose components to reduced "anti-degradation barrier", resulting to improve the enzymatic saccharification from 12.36 % to 90.56 %. In addition, DES pretreatment can break the β-O-4 bond between the lignin units resulting in a decline in molecular weight from 3187 g/mol to 1112 g/mol (0-6 h). However, long pretreatment time resulted regenerated lignin samples repolymerization. Finally, DES has good recoverability which showed saccharification still can reach 51.51 % at 6 h following four recycling rounds and regenerated lignin also had a typical and well-preserved structure. In general, this work offers important information for industrial biorefinery technologies and lignin valorization.
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Affiliation(s)
- Gaomin Wang
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Mingjun Huang
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Fucheng Li
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Qiang Li
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Fushan Chen
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Songlin Wang
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Zhe Ling
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Zhe Ji
- College of Marine Science and Bioengineering, Qingdao University of Science and Technology, Qingdao 266042, China.
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3
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Cellulosic Ethanol Production from Weed Biomass Hydrolysate of Vietnamosasa pusilla. Polymers (Basel) 2023; 15:polym15051103. [PMID: 36904344 PMCID: PMC10007069 DOI: 10.3390/polym15051103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
Lignocellulosic biomass can be used as a renewable and sustainable energy source to help reduce the consequences of global warming. In the new energy age, the bioconversion of lignocellulosic biomass into green and clean energy displays remarkable potential and makes efficient use of waste. Bioethanol is a biofuel that can diminish reliance on fossil fuels while minimizing carbon emissions and increasing energy efficiency. Various lignocellulosic materials and weed biomass species have been selected as potential alternative energy sources. Vietnamosasa pusilla, a weed belonging to the Poaceae family, contains more than 40% glucan. However, research on the applications of this material is limited. Thus, here we aimed to achieve maximum fermentable glucose recovery and bioethanol production from weed biomass (V. pusilla). To this end, V. pusilla feedstocks were treated with varying concentrations of H3PO4 and then subjected to enzymatic hydrolysis. The results indicated that after pretreatment with different concentrations of H3PO4, the glucose recovery and digestibility at each concentration were markedly enhanced. Moreover, 87.5% of cellulosic ethanol was obtained from V. pusilla biomass hydrolysate medium without detoxification. Overall, our findings reveal that V. pusilla biomass can be introduced into sugar-based biorefineries to produce biofuels and other valuable chemicals.
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Huang C, Zhan Y, Cheng J, Wang J, Meng X, Fang G, Ragauskas AJ. The bamboo delignification saturation point in alkaline hydrogen peroxide pretreatment and its association with enzymatic hydrolysis. BIORESOURCE TECHNOLOGY 2022; 359:127462. [PMID: 35700894 DOI: 10.1016/j.biortech.2022.127462] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
A delignification saturation point (DSP) was observed for bamboo alkaline hydrogen peroxide pretreatment (AHP). Lignin removal was increased from 52.23% to ∼70% when increasing H2O2 dosage from 0% to 2% at the optimum pH, but it cannot be further reinforced as increasing the H2O2. With partial lignin preserved, the glucan hydrolysis yield was found to have a ceiling of ∼80%. This study indicated a strong association between enzymatic digestibility and lignin removal. Anatomical analysis by fluorescence microscope and confocal Raman microscope revealed that the undegradable lignin was mainly existing in the cell corner of sclerenchyma fibers, causing the DSP in the bamboo AHP. Finally, the residual lignin in pretreated bamboo was characterized with GPC, HSQC NMR, and 31P NMR, which revealed the nature of DSP. This study could help to understand the lignin modification during the AHP and further contribute to the establishment of a chemical-saving biorefinery.
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Affiliation(s)
- Chen Huang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042
| | - Yunni Zhan
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042
| | - Jinyuan Cheng
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042
| | - Jia Wang
- Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China
| | - Xianzhi Meng
- Department of Chemical and Biomolecular Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, USA
| | - Guigan Fang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042
| | - Arthur J Ragauskas
- Department of Chemical and Biomolecular Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, USA; Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, The University of Tennessee Institute of Agriculture, Knoxville, TN 37996, USA; UTK-ORNL Joint Institute for Biological Science, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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5
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Zhou X, Guan C, Xu Y, Yang S, Huang C, Sha J, Dai H. Mechanistic insights into morphological and chemical changes during benzenesulfonic acid pretreatment and simultaneous saccharification and fermentation process for ethanol production. BIORESOURCE TECHNOLOGY 2022; 360:127586. [PMID: 35798163 DOI: 10.1016/j.biortech.2022.127586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
The anatomical and histochemical characterization of pretreated substrates is essential for the further valorization of biomass during the biorefinery process. In this work, the benzenesulfonic acid (BA)-treated substrates were employed for simultaneous saccharification and fermentation (SSF) of ethanol for the first time. An ethanol yield of 50.36% was attained at 10% solids loading and 47.45 g/L of ethanol accumulated at 30 % solids loading. The dramatic improvements could result from the deconstruction of cell walls, which were evidenced by fluorescence microscope and confocal Raman microscopy spectra. Additionally, for a thorough comprehension of the inherent chemistry of lignin during the BA pretreatment, the changes in lignin structure features were identified for the first time by gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). In summary, this study tried to probe the possibility of BA-treated Miscanthus for the SSF process and unveiled the mechanism of the efficient BA pretreatment.
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Affiliation(s)
- Xuelian Zhou
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China
| | - Chunlong Guan
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China
| | - Yexuan Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China
| | - Shilong Yang
- Advanced Analysis & Testing Center, Nanjing Forestry University, Nanjing 210037, China
| | - Chen Huang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China
| | - Jiulong Sha
- Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, School of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China
| | - Hongqi Dai
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
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6
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Zhan Y, Cheng J, Liu X, Huang C, Wang J, Han S, Fang G, Meng X, Ragauskas AJ. Assessing the availability of two bamboo species for fermentable sugars by alkaline hydrogen peroxide pretreatment. BIORESOURCE TECHNOLOGY 2022; 349:126854. [PMID: 35176465 DOI: 10.1016/j.biortech.2022.126854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/09/2022] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
This study comprehensively investigated two bamboo species (i.e. Neosinocalamus affinis and Phyllostachys edulis) in terms of their cell wall ultrastructure, chemical compositions, enzymatic saccharification, and lignin structure before and after alkaline hydrogen peroxide pretreatment (AHP). During AHP, Neosinocalamus affinis (NAB) had higher delignification than Phyllostachys edulis (PEB), and thus showed better enzymatic digestibility (93.05% vs 53.57% for glucan). The fundamental chemical behavior of the bamboo lignins was analyzed by fluorescence microscope (FM), confocal Raman microscope (CRM), molecular weight analysis, and 2D HSQC-NMR. Results indicated that the PEB has thicker cell wall and more concentrated lignin in its compound middle lamella and cell corner middle lamella than NAB. Moreover, PEB lignin contains more G units (S/G of 0.95), in evident contrast to that of NAB lignin (S/G of 1.30), which favor the formation of C-C linkages, thus impeding its degradation during the AHP.
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Affiliation(s)
- Yunni Zhan
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China
| | - Jinyuan Cheng
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China
| | - Xuze Liu
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China
| | - Chen Huang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China; Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China.
| | - Jia Wang
- Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China
| | - Shanming Han
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China
| | - Guigan Fang
- Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Jiangsu Province Key Laboratory of Biomass Energy and Materials, Nanjing 210042, China; Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China
| | - Xianzhi Meng
- Department of Chemical and Biomolecular Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, USA
| | - Arthur J Ragauskas
- Department of Chemical and Biomolecular Engineering, University of Tennessee Knoxville, Knoxville, TN 37996, USA; Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, The University of Tennessee Institute of Agriculture, Knoxville, TN 37996, USA; Joint Institute for Biological Science, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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7
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Ding D, Hu J, Hui L, Liu Z, Shao L. Valorization of Miscanthus × giganteus by γ-Valerolactone/H 2O/FeCl 3 system toward efficient conversion of cellulose and hemicelluloses. Carbohydr Polym 2021; 270:118388. [PMID: 34364629 DOI: 10.1016/j.carbpol.2021.118388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 10/21/2022]
Abstract
γ-Valerolactone (GVL), a biomass-derived green chemical, offers an environmentally responsible solvent for conversion of lignocellulose to high value-added chemicals. Herein, we report a two-step process for directly producing cellulosic residual, furfural and lignin from Miscanthus × giganteus (M. × giganteus) bypassing the isolation of xylose, which exhibits promising advantage in energy reduction. The optimized pretreatment (100 mM FeCl3 at 160 °C for 60 min) induced significant xylan removal (98.4%), resulting in rugged fibre surface, thus leading to the peak cellulose conversion of 99.3%. Furfural yield in the second step reached to 76.6% after 100 mM FeCl3 catalyzed GVL/H2O treatment at 180 °C for 10 min without addition of any chemical. The extracted lignin showed representative structure (such as β-O-4', β-β' linkages) and medium molecular weight (4275.5 g/mol). 79.6% of furfural can be recovered by distillation. This study proposes a systematic and energy efficient approach for maximizing biomass utilization.
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Affiliation(s)
- Dayong Ding
- College of Light Industry Science and Engineering, Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China; Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
| | - Jianquan Hu
- College of Light Industry Science and Engineering, Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Lanfeng Hui
- College of Light Industry Science and Engineering, Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Zhong Liu
- College of Light Industry Science and Engineering, Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Lupeng Shao
- Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
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8
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Xue F, Li W, An S, Li C, Li X, Wu M, Wei X. Ethylene glycol based acid pretreatment of corn stover for cellulose enzymatic hydrolysis. RSC Adv 2021; 11:14140-14147. [PMID: 35423947 PMCID: PMC8697755 DOI: 10.1039/d0ra10877d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/08/2021] [Indexed: 11/21/2022] Open
Abstract
A highly efficient pretreatment strategy using ethylene glycol with dilute sulfuric acid was developed for the fractionation of lignocellulose. The pretreatment behaviors were related to the composition analysis and structure of the samples analyzed by SEM, XRD, FTIR and 2D HSQC NMR, resulting in 80.3% delignification and 84.7% retention of cellulose under the selected conditions (120 °C, 60 min, and 0.6 wt% H2SO4 (w/w)). The enzymatic hydrolysis sugar yield significantly increased from 24.1 to 70.6% (3 FPU g-1), which displayed immense improvement compared with untreated corn stover (24.1%), nearly 3-fold higher than its untreated counterparts. Besides, the regenerated lignin could be fitted to valorize renewable aromatic chemicals and alkane fuels. The present study shows that the pretreatment is a simple, efficient and promising process for corn stover biorefinery.
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Affiliation(s)
- Fengyang Xue
- Laboratory of Basic Research in Biomass Conversion and Utilization, University of Science and Technology of China Hefei 230026 PR China
| | - Wenzhi Li
- Laboratory of Basic Research in Biomass Conversion and Utilization, University of Science and Technology of China Hefei 230026 PR China
- Institute of Energy, Hefei Comprehensive National Science Center Hefei 230031 China
| | - Shengxin An
- Institute of Chemical Engineering, Anhui University of Science and Technology Huainan 232001 PR China
| | - Cunshuo Li
- Laboratory of Basic Research in Biomass Conversion and Utilization, University of Science and Technology of China Hefei 230026 PR China
| | - Xu Li
- Laboratory of Basic Research in Biomass Conversion and Utilization, University of Science and Technology of China Hefei 230026 PR China
| | - Mingwei Wu
- Laboratory of Basic Research in Biomass Conversion and Utilization, University of Science and Technology of China Hefei 230026 PR China
| | - Xiuzhi Wei
- Laboratory of Basic Research in Biomass Conversion and Utilization, University of Science and Technology of China Hefei 230026 PR China
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9
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Zhang X. Visualising lignin quantitatively in plant cell walls by micro-Raman spectroscopy. RSC Adv 2021; 11:13124-13129. [PMID: 35423841 PMCID: PMC8697320 DOI: 10.1039/d1ra01825f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/31/2021] [Indexed: 11/21/2022] Open
Abstract
As a main component in plant cell wall, lignin is commonly determined by wet chemical analysis which only provides general information rather than specifics for different cell wall layers. To address this issue, we attempted to use micro-Raman spectroscopy for quantitative visualisation of the lignin in various cell wall layers during delignification.
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Affiliation(s)
- Xun Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University Beijing 100083 P. R. China
- National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials Fuzhou 350002 P. R. China
- Qilu University of Technology, Shandong Academy of Sciences, State Key Laboratory of Biobased Material and Green Papermaking Jinan 250353 P. R. China
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10
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Breeding Targets to Improve Biomass Quality in Miscanthus. Molecules 2021; 26:molecules26020254. [PMID: 33419100 PMCID: PMC7825460 DOI: 10.3390/molecules26020254] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/31/2020] [Accepted: 01/01/2021] [Indexed: 01/02/2023] Open
Abstract
Lignocellulosic crops are attractive bioresources for energy and chemicals production within a sustainable, carbon circular society. Miscanthus is one of the perennial grasses that exhibits great potential as a dedicated feedstock for conversion to biobased products in integrated biorefineries. The current biorefinery strategies are primarily focused on polysaccharide valorization and require severe pretreatments to overcome the lignin barrier. The need for such pretreatments represents an economic burden and impacts the overall sustainability of the biorefinery. Hence, increasing its efficiency has been a topic of great interest. Inversely, though pretreatment will remain an essential step, there is room to reduce its severity by optimizing the biomass composition rendering it more exploitable. Extensive studies have examined the miscanthus cell wall structures in great detail, and pinpointed those components that affect biomass digestibility under various pretreatments. Although lignin content has been identified as the most important factor limiting cell wall deconstruction, the effect of polysaccharides and interaction between the different constituents play an important role as well. The natural variation that is available within different miscanthus species and increased understanding of biosynthetic cell wall pathways have specified the potential to create novel accessions with improved digestibility through breeding or genetic modification. This review discusses the contribution of the main cell wall components on biomass degradation in relation to hydrothermal, dilute acid and alkaline pretreatments. Furthermore, traits worth advancing through breeding will be discussed in light of past, present and future breeding efforts.
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11
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Liu W, Zhuo S, Si M, Yuan M, Shi Y. Derived high reducing sugar and lignin colloid particles from corn stover. BMC Chem 2020; 14:72. [PMID: 33303003 PMCID: PMC7727252 DOI: 10.1186/s13065-020-00725-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/01/2020] [Indexed: 11/30/2022] Open
Abstract
Lignocellulosic biomass is considered as the largest potential candidate to develop alternative energy, such as biofuel, biomaterial. However, the efficient conversion of cellulose and practical utilization of lignin are great challenges for sustainable biorefinery. In this study, high reducing sugar yield and different size of lignin colloid particles (LCPs) were obtained via tetrahydrofuran-water (THF-H2O) pretreatment of corn stover (CS). THF-H2O as a co-solvent, could efficiently dissolve lignin and retain cellulose. After the pretreatment, 640.87 mg/g of reducing sugar was produced, that was 6.66-fold higher than that of the untreated CS. Meanwhile, the pretreatment liquor could form spherical LCPs with different sizes ranged from 202 to 732 nm through self-assembly. We studied the optimal pretreatment condition to simultaneously realize the high reducing sugar yield (588.4 mg/g) and excellent LCPs preparation with average size of 243 nm was under TH22 (THF-H2O pretreatment at 120 °C for 2 h). To further explore the formation of LCPs with different sizes. We studied the lignin structure changes of various conditions, concluded the size of LCPs was related to the lignin concentration and syringyl/guaiacyl (S/G) ratio. As the increase of the lignin concentration and S/G, the sizes of LCPs were increased. G-type lignin was easier to dissolve in the mild pretreatment supernatant, contributing to form smaller LCPs with a good dispersibility. In the severe condition, both of S and G-type lignin were dissolved due to the lignin depolymerization, formed the larger sphere particles. This work provides a novel perspective for the technical design of lignocellulosic biomass conversion.
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Affiliation(s)
- Wei Liu
- School of Life Science, Tonghua Normal University, Tonghua, 134000, China
| | - Shengnan Zhuo
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China.
- Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China.
- School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Mengying Si
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
- Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Mengting Yuan
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
- Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
| | - Yan Shi
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
- Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha, 410083, China
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12
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Bhatia R, Winters A, Bryant DN, Bosch M, Clifton-Brown J, Leak D, Gallagher J. Pilot-scale production of xylo-oligosaccharides and fermentable sugars from Miscanthus using steam explosion pretreatment. BIORESOURCE TECHNOLOGY 2020; 296:122285. [PMID: 31715557 PMCID: PMC6920740 DOI: 10.1016/j.biortech.2019.122285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 05/12/2023]
Abstract
This study investigated pilot-scale production of xylo-oligosaccharides (XOS) and fermentable sugars from Miscanthus using steam explosion (SE) pretreatment. SE conditions (200 °C; 15 bar; 10 min) led to XOS yields up to 52 % (w/w of initial xylan) in the hydrolysate. Liquid chromatography-mass spectrometry demonstrated that the solubilised XOS contained bound acetyl- and hydroxycinnamate residues, physicochemical properties known for high prebiotic effects and anti-oxidant activity in nutraceutical foods. Enzymatic hydrolysis of XOS-rich hydrolysate with commercial endo-xylanases resulted in xylobiose yields of 380 to 500 g/kg of initial xylan in the biomass after only 4 h, equivalent to ~74 to 90 % conversion of XOS into xylobiose. Fermentable glucose yields from enzymatic hydrolysis of solid residues were 8 to 9-fold higher than for untreated material. In view of an integrated biorefinery, we demonstrate the potential for efficient utilisation of Miscanthus for the production of renewable sources, including biochemicals and biofuels.
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Affiliation(s)
- Rakesh Bhatia
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EE, UK.
| | - Ana Winters
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EE, UK
| | - David N Bryant
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EE, UK
| | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EE, UK
| | - John Clifton-Brown
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EE, UK
| | - David Leak
- Department of Biology & Biochemistry, University of Bath, Bath BA2 7AY, UK
| | - Joe Gallagher
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Plas Gogerddan, Aberystwyth SY23 3EE, UK
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Structural Characterization and Antioxidant Activity of Milled Wood Lignin from Xylose Residue and Corncob. Polymers (Basel) 2019; 11:polym11122092. [PMID: 31847271 PMCID: PMC6960613 DOI: 10.3390/polym11122092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/06/2019] [Accepted: 12/12/2019] [Indexed: 11/16/2022] Open
Abstract
Xylose residue (XR), after diluted acid treatment of corncob, consists of cellulose and lignin. However, structural changes of XR lignin have not been investigated comprehensively, and this has seriously hindered the efficient utilization of lignin. In this study, corncob milled wood lignin (CC MWL), and xylose residue milled wood lignin (XR MWL) were isolated according to the modified milled wood lignin (MWL) method. The structural features of two lignin fractions were thoroughly investigated via fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and two dimensional nuclear magnetic resonance (2D NMR) spectroscopy techniques. XR MWL with higher yield and lower bound carbohydrate contents presented more phenolic OH contents than CC MWL due to partial cleavage of β-O-4. Furthermore, the molecular weights of XR MWL were increased, possibly because of condensation of the lignin during the xylose production. A study on antioxidant activity showed that XR lignin had better radical scavenging ability than that of 2,6-Di-tert-butyl-4-methyl-phenol (BHT) and CC MWL. The results suggested that the lignin in xylose residue, showing great antioxidant properties, has potential applications in food additives.
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Guo Z, Zhang Q, You T, Ji Z, Zhang X, Qin Y, Xu F. Heteropoly acids enhanced neutral deep eutectic solvent pretreatment for enzymatic hydrolysis and ethanol fermentation of Miscanthus x giganteus under mild conditions. BIORESOURCE TECHNOLOGY 2019; 293:122036. [PMID: 31479857 DOI: 10.1016/j.biortech.2019.122036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/16/2019] [Accepted: 08/17/2019] [Indexed: 06/10/2023]
Abstract
To improve the neutral DES (choline chloride/glycerol) pretreatment performance, three environmentally friendly heteropoly acids (phosphotungstic, phosphomolybdic and silicotungstic acids) were used as catalysts. Pretreatment with silicotungstic acid at 120 °C for 3 h resulted in 97.3% of enzymatic digestibility at an enzyme loading of 15FPU/g substrate, which was approximately eight times more than that of raw samples. More importantly, 80% of glucose yield was obtained within 12 h. Simultaneously, 81.8% of ethanol yield was achieved in the SSSF process. The efficient conversion was ascribed to the significant delignification (89.5%), which resulted in the exposure of more accessible specific surface area. This was attributed to that the proton (H+) from heteropoly acids could significantly contribute to the lignin degradation. Intriguingly, trace acetic acid (0.39 g/L) and HMF (0.21-0.95 g/L) in the pretreatment liquor were produced without any significant deleterious effects. These discoveries provide new insights for efficient biomass conversion under mild conditions.
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Affiliation(s)
- Zongwei Guo
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Qilin Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Tingting You
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Zhe Ji
- College of Marine Science and Biological Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Xun Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Yanlin Qin
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Feng Xu
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
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Abstract
Background: Common buckwheat (Fagopyrum esculentum Moench) is an annual spring-emerging crop that is classified among the dicotyledons, due to the manner of its cultivation, use, and chemical composition of seeds. The use of buckwheat straw for energy purposes—for example, for the production of second generation bioethanol—might enable its wider application and increase the cost-effectiveness of tillage. Methods: In this study, we examined the usability of buckwheat straw for the production of bioethanol. We pretreated the raw material with ionic liquids and subsequently performed enzymatic hydrolysis and alcoholic fermentation. The obtained chemometric data were analyzed using the Partial Least Squares (PLS) regression model. PLS regression in combination with spectral analysis within the near-infrared (NIR) spectrum allowed for the rapid determination of the amount of cellulose in the raw material and also provided information on the changes taking place in its structure. Results: We obtained good results for the combination of 1-ethyl-3-methylimidazolium acetate as the ionic liquid and Cellic CTec2 as the enzymatic preparation for the pretreatment of buckwheat straw. The highest concentration of glucose following 72 h of enzymatic hydrolysis was found to be around 5.5 g/dm3. The highest concentration of ethanol (3.31 g/dm3) was obtained with the combination of 1-butyl-3-methylimidazolium acetate for the pretreatment and cellulase from Trichoderma reesei for enzymatic hydrolysis. Conclusions: In summary, the efficiency of the fermentation process is strictly associated with the pool of available fermenting sugars, and it depends on the type of ionic liquid used during the pretreatment and on the enzymatic preparation. It is possible to obtain bioethanol from buckwheat straw using ionic liquid for pretreatment of the raw material prior to the enzymatic hydrolysis and alcoholic fermentation of the material.
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Zhang H, Huang S, Wei W, Zhang J, Xie J. Investigation of alkaline hydrogen peroxide pretreatment and Tween 80 to enhance enzymatic hydrolysis of sugarcane bagasse. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:107. [PMID: 31073331 PMCID: PMC6498686 DOI: 10.1186/s13068-019-1454-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/25/2019] [Indexed: 05/25/2023]
Abstract
BACKGROUND Due to the intact structure of lignocellulosic biomass, pretreatment was a prerequisite to improve the enzymatic hydrolysis by disrupting the recalcitrant lignocellulose and increasing the accessibility of cellulose to enzyme. In this study, an alkaline hydrogen peroxide (AHP) pretreatment of sugarcane bagasse with various loadings of H2O2 (1.25-6.25 wt%) at temperatures of 60-160 °C was proposed to degrade hemicellulose/lignin and improve the enzymatic digestibility. RESULTS It was found that increasing H2O2 loadings during pretreatment lead to the enhancement of substrate digestibility, whereas the alkali (only NaOH)-pretreated solid generated higher glucose yield than that pretreated under AHP pretreatment with lower loading of H2O2. This enhancement of enzymatic digestibility was due to the degradation of hemicellulose and lignin. Furthermore, Tween 80 was added to promote enzymatic digestibility, however, the increased yields were different with various substrates and hydrolysis time. The highest glucose yield of 77.6% was obtained after pretreatment at 160 °C for 60 min with 6.25% H2O2 and the addition of Tween 80, representing 89.1% of glucose in pretreated substrate. CONCLUSIONS This study demonstrated that the AHP pretreatment could greatly enhance the enzymatic saccharification. The addition of Tween 80 played remarkable performances in promoting the glucose yield during enzymatic hydrolysis by stabilizing and protecting the enzyme activity. This study provided an economical feasible and gradual process for the generation of glucose, which will be subsequently converted to bioethanol and bio-chemicals.
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Affiliation(s)
- Hongdan Zhang
- College of Forestry and Landscape Architecture, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, South China Agricultural University, Guangzhou, 510642 People’s Republic of China
- CAS Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Guangzhou, 510640 People’s Republic of China
| | - Shihang Huang
- College of Forestry and Landscape Architecture, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, South China Agricultural University, Guangzhou, 510642 People’s Republic of China
| | - Weiqi Wei
- College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, 210037 People’s Republic of China
| | - Jiajie Zhang
- College of Forestry and Landscape Architecture, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, South China Agricultural University, Guangzhou, 510642 People’s Republic of China
| | - Jun Xie
- College of Forestry and Landscape Architecture, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture, South China Agricultural University, Guangzhou, 510642 People’s Republic of China
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Mohapatra S, Mishra C, Merritt BB, Pattathil S, Thatoi H. Evaluating the Role of Ultrasonication-Assisted Alkali Pretreatment and Enzymatic Hydrolysis on Cellwall Polysaccharides of Pennisetum
Grass Varieties as Potential Biofuel Feedstock. ChemistrySelect 2019. [DOI: 10.1002/slct.201802187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sonali Mohapatra
- Department of Biotechnology; College of Engineering and Technology; Biju Pattnaik University of Technology; Bhubaneswar- 751003 India
| | - Chinmaya Mishra
- Department of Biotechnology; College of Engineering and Technology; Biju Pattnaik University of Technology; Bhubaneswar- 751003 India
| | - Brian B Merritt
- Complex Carbohydrate Research Center; University of Georgia, GA 30602 USA and BioEnergy Science Center (BESC); Oak Ridge National Laboratory; Oak Ridge, TN 37831 USA
| | - Sivakumar Pattathil
- Complex Carbohydrate Research Center; University of Georgia, GA 30602 USA and BioEnergy Science Center (BESC); Oak Ridge National Laboratory; Oak Ridge, TN 37831 USA
| | - Hrudayanath Thatoi
- Department of Biotechnology; North Orissa University; Sriram Chandra vihar, Takatpur Baripada- 757003, Odisha India
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Paës G, Navarro D, Benoit Y, Blanquet S, Chabbert B, Chaussepied B, Coutinho PM, Durand S, Grigoriev IV, Haon M, Heux L, Launay C, Margeot A, Nishiyama Y, Raouche S, Rosso MN, Bonnin E, Berrin JG. Tracking of enzymatic biomass deconstruction by fungal secretomes highlights markers of lignocellulose recalcitrance. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:76. [PMID: 30976326 PMCID: PMC6442405 DOI: 10.1186/s13068-019-1417-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/23/2019] [Indexed: 05/12/2023]
Abstract
BACKGROUND Lignocellulose biomass is known as a recalcitrant material towards enzymatic hydrolysis, increasing the process cost in biorefinery. In nature, filamentous fungi naturally degrade lignocellulose, using an arsenal of hydrolytic and oxidative enzymes. Assessment of enzyme hydrolysis efficiency generally relies on the yield of glucose for a given biomass. To better understand the markers governing recalcitrance to enzymatic degradation, there is a need to enlarge the set of parameters followed during deconstruction. RESULTS Industrially-pretreated biomass feedstocks from wheat straw, miscanthus and poplar were sequentially hydrolysed following two steps. First, standard secretome from Trichoderma reesei was used to maximize cellulose hydrolysis, producing three recalcitrant lignin-enriched solid substrates. Then fungal secretomes from three basidiomycete saprotrophs (Laetisaria arvalis, Artolenzites elegans and Trametes ljubarskyi) displaying various hydrolytic and oxidative enzymatic profiles were applied to these recalcitrant substrates, and compared to the T. reesei secretome. As a result, most of the glucose was released after the first hydrolysis step. After the second hydrolysis step, half of the remaining glucose amount was released. Overall, glucose yield after the two sequential hydrolyses was more dependent on the biomass source than on the fungal secretomes enzymatic profile. Solid residues obtained after the two hydrolysis steps were characterized using complementary methodologies. Correlation analysis of several physico-chemical parameters showed that released glucose yield was negatively correlated with lignin content and cellulose crystallinity while positively correlated with xylose content and water sorption. Water sorption appears as a pivotal marker of the recalcitrance as it reflects chemical and structural properties of lignocellulosic biomass. CONCLUSIONS Fungal secretomes applied to highly recalcitrant biomass samples can further extend the release of the remaining glucose. The glucose yield can be correlated to chemical and physical markers, which appear to be independent from the biomass type and secretome. Overall, correlations between these markers reveal how nano-scale properties (polymer content and organization) influence macro-scale properties (particle size and water sorption). Further systematic assessment of these markers during enzymatic degradation will foster the development of novel cocktails to unlock the degradation of lignocellulose biomass.
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Affiliation(s)
- Gabriel Paës
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, Reims, France
| | - David Navarro
- INRA, Aix Marseille Univ., UMR1163, BBF, Biodiversité et Biotechnologie Fongiques, Marseille, France
- INRA, Aix-Marseille Univ., UMR1163, CIRM-CF, Marseille, France
| | - Yves Benoit
- IFP Energies Nouvelles, Rueil-Malmaison, France
| | | | - Brigitte Chabbert
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, Reims, France
| | | | - Pedro M. Coutinho
- CNRS, Aix-Marseille Univ., UMR7857 AFMB, Architecture et Fonction des Macromolécules Biologiques, Marseille, France
| | - Sylvie Durand
- INRA, UR1268 Biopolymères Interactions Assemblages, Nantes, France
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, CA USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA USA
| | - Mireille Haon
- INRA, Aix Marseille Univ., UMR1163, BBF, Biodiversité et Biotechnologie Fongiques, Marseille, France
| | - Laurent Heux
- CNRS, Univ. Grenoble Alpes, CERMAV, Grenoble, France
| | - Charlène Launay
- INRA, UR1268 Biopolymères Interactions Assemblages, Nantes, France
| | | | | | - Sana Raouche
- INRA, Aix Marseille Univ., UMR1163, BBF, Biodiversité et Biotechnologie Fongiques, Marseille, France
| | - Marie-Noëlle Rosso
- INRA, Aix Marseille Univ., UMR1163, BBF, Biodiversité et Biotechnologie Fongiques, Marseille, France
| | - Estelle Bonnin
- INRA, UR1268 Biopolymères Interactions Assemblages, Nantes, France
| | - Jean-Guy Berrin
- INRA, Aix Marseille Univ., UMR1163, BBF, Biodiversité et Biotechnologie Fongiques, Marseille, France
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Dong M, Wang S, Xu F, Wang J, Yang N, Li Q, Chen J, Li W. Pretreatment of sweet sorghum straw and its enzymatic digestion: insight into the structural changes and visualization of hydrolysis process. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:276. [PMID: 31768194 PMCID: PMC6874820 DOI: 10.1186/s13068-019-1613-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/10/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND The efficient utilization of lignocellulosic biomass for biofuel production has received increasing attention. Previous studies have investigated the pretreatment process of biomass, but the detailed enzymatic hydrolysis process of pretreated biomass remains largely unclear. Thus, this study investigated the pretreatment efficiency of dilute alkali, acid, hydrogen peroxide and its ultimate effects on enzymatic hydrolysis. Furthermore, to better understand the enzymatic digestion process of alkali-pretreated sweet sorghum straw (SSS), multimodal microscopy techniques were used to visualize the enzymatic hydrolysis process. RESULT After pretreatment with alkali, an enzymatic hydrolysis efficiency of 86.44% was obtained, which increased by 99.54% compared to the untreated straw (43.23%). The FTIR, XRD and SEM characterization revealed a sequence of microstructural changes occurring in plant cell walls after pretreatment, including the destruction of lignin-polysaccharide interactions, the increase of porosity and crystallinity, and reduction of recalcitrance. During the course of hydrolysis, the cellulase dissolved the cell walls in the same manner and the digestion firstly occurred from the middle of cell walls and then toward the cell wall corners. The CLSM coupled with fluorescent labeling demonstrated that the sclerenchyma cells and vascular bundles in natural SSS were highly lignified, which caused the nonproductive bindings of cellulase on lignin. However, the efficient delignification significantly increased the accessibility and digestibility of cellulase to biomass, thereby improving the saccharification efficiency. CONCLUSION This work will be helpful in investigating the biomass pretreatment and its structural characterization. In addition, the visualization results of the enzymatic hydrolysis process of pretreated lignocellulose could be used for guidance to explore the lignocellulosic biomass processing and large-scale biofuel production.
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Affiliation(s)
- Miaoyin Dong
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, 730000 Gansu People’s Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 People’s Republic of China
| | - Shuyang Wang
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, 730000 Gansu People’s Republic of China
- Institute of Biology, Gansu Academy of Sciences, 197 Dingxi South Rd., Lanzhou, 730000 Gansu People’s Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 People’s Republic of China
| | - Fuqiang Xu
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, 730000 Gansu People’s Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 People’s Republic of China
| | - Junkai Wang
- College of Physics and Electronic Engineering, Northwest Normal University, Anning Rd., Lanzhou, 730000 Gansu People’s Republic of China
| | - Ning Yang
- College of Life Sciences, Northwest Normal University, Anning Rd., Lanzhou, 730000 Gansu People’s Republic of China
| | - Qiaoqiao Li
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, 730000 Gansu People’s Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 People’s Republic of China
| | - Jihong Chen
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, 730000 Gansu People’s Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 People’s Republic of China
| | - Wenjian Li
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, 730000 Gansu People’s Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049 People’s Republic of China
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20
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Wang Z, Hou X, Sun J, Li M, Chen Z, Gao Z. Comparison of ultrasound-assisted ionic liquid and alkaline pretreatment of Eucalyptus for enhancing enzymatic saccharification. BIORESOURCE TECHNOLOGY 2018; 254:145-150. [PMID: 29413915 DOI: 10.1016/j.biortech.2018.01.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/03/2018] [Accepted: 01/04/2018] [Indexed: 05/14/2023]
Abstract
Two ultrasound-assisted pretreatment technologies, ultrasound-assisted alkaline and ultrasound-assisted aqueous ionic liquid tetrabutylammonium hydroxide ([TBA][OH]), are compared systematically in regard to enzymatic saccharification. Pretreated Eucalyptus samples were characterized by powder X-ray diffraction, 13C cross polarization/magic-angle spinning solid state NMR spectroscopy, Fourier transform infrared spectroscopy, Scanning electron microscope (SEM) and chemistry composition analysis. These results not only explain the enzymatic saccharification difference between samples from the microstructure level, but also provide helpful information for relevant pretreatment research. Ultrasound-assisted [TBA][OH] pretreatment acquired a significant enhancement in the initial enzymatic rate of cellulose (79.39 mg/g/h), and a reducing sugar yield of 426.6 mg/g at 48 h. The pretreatment combining inexpensive aqueous ionic liquid and ultrasound may provide a promising strategy in the field of bio-refinery because of its unique advantages.
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Affiliation(s)
- Zhinan Wang
- College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China
| | - Xianfeng Hou
- College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China
| | - Jin Sun
- College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China
| | - Meng Li
- College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China
| | - Zhiyong Chen
- Zhongshan Collaborative Innovation Center of National Analytical Center of China, Zhongshan 528476, China
| | - Zhenzhong Gao
- College of Materials & Energy, South China Agricultural University, Guangzhou 510642, China.
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21
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Isaac A, de Paula J, Viana CM, Henriques AB, Malachias A, Montoro LA. From nano- to micrometer scale: the role of microwave-assisted acid and alkali pretreatments in the sugarcane biomass structure. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:73. [PMID: 29588658 PMCID: PMC5863382 DOI: 10.1186/s13068-018-1071-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 03/08/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND To date, great strides have been made in elucidating the role of thermochemical pretreatments in the chemical and structural features of plant cell walls; however, there is no clear picture of the plant recalcitrance and its relationship to deconstruction. Previous studies precluded full answers due to the challenge of multiscale features of plant cell wall organization. Complementing the previous efforts, we undertook a systematic, multiscale, and integrated approach to track the effect of microwave-assisted H2SO4 and NaOH treatments on the hierarchical structure of plants, i.e., from a nano- to micrometer scale. We focused on the investigation of the highly recalcitrant sclerenchyma cell walls from sugarcane bagasse. RESULTS Through atomic force microscopy and X-ray diffraction analyses, remarkable details of the assembly of cellulose microfibrils not previously seen were revealed. Following the H2SO4 treatment, we observed that cellulose microfibrils were almost double the width of the alkali pretreated sample at the temperature of 160 °C. Such enlargement led to a greater contact between cellulose chains, with a subsequent molecule alignment, as indicated by the X-ray diffraction (XRD) results with the conspicuous expansion of the average crystallite size. The delignification process had little effect on the local nanometer-sized arrangement of cellulose molecules. However, the rigidity and parallel alignment of cellulose microfibrils were partially degraded. The XRD analysis also agrees with these findings as evidenced by large momentum transfer vectors (q > 20 nm-1), interpreted as indicators of the long-range order of cell wall components, which were similar for all the studied samples except with application of the NaOH treatment at 160 °C. These changes were followed by the eventual swelling of the fiber cell walls. CONCLUSIONS Based on an integrated approach, we presented multidimensional architectural models of cell wall deconstruction resulting from microwave-assisted pretreatments. We provided direct evidence supporting the idea that hemicellulose is the main barrier for the swelling of cellulose microfibrils, whereas lignin adds rigidity to cell walls. Our findings shed light on the design of more efficient strategies, not only for the conversion of biomass to fuels but also for the production of nanocellulose, which has great potential for several applications such as composites, rheology modifiers, and pharmaceuticals.
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Affiliation(s)
- Augusta Isaac
- Department of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 Brazil
| | - Jéssica de Paula
- Microscopy Center, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 Brazil
| | - Carlos Martins Viana
- Department of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 Brazil
| | - Andréia Bicalho Henriques
- Mining Engineering Department, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 Brazil
| | - Angelo Malachias
- Department of Physics, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 Brazil
| | - Luciano A. Montoro
- Department of Chemistry, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 Brazil
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Zhu N, Wu D, Chen K. Label-free visualization of fruit lignification: Raman molecular imaging of loquat lignified cells. PLANT METHODS 2018; 14:58. [PMID: 30008794 PMCID: PMC6043974 DOI: 10.1186/s13007-018-0328-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/06/2018] [Indexed: 05/10/2023]
Abstract
BACKGROUND Flesh lignification, leading to increased fruit firmness, has been reported in several kinds of fruit. Understanding the mechanisms underlying fruit lignification is important to optimize the postharvest storage strategies and reduce the quality deterioration of postharvest fruit. Especially cellular level investigation of lignin deposition in fruits provides novel insight for deciphering the mechanisms underlying fruit lignification. The primary objective of this study was to establish a procedure of using Raman microspectroscopy technique to depict fruit lignification at the cell level. RESULTS Lignified cells, a special kind of cells contained high lignin content, were found abundantly scattered in red-fleshed 'Luoyangqing' loquat. Whereas these special lignified cells were barely detected in 'Baisha' loquat flesh. Dominant Raman bands of lignified cells were found primarily attributed to lignin (1664, 1628, 1603, 1467, and 1272 cm-1), cellulose (1383, 1124 and 1098 cm-1) and pectin (852 and 1740 cm-1). The band intensity correlation analysis indicated the peak at 1335 cm-1 assigned to either lignin or cellulose in previous works was related to lignin for the lignified cells. Multi-peaks Gaussian fitting successfully resolved the overlapped fingerprint peaks of lignin in 1550-1700 cm-1 into three independent peaks, which were assigned to different functional groups of lignin. Furthermore, the spatially resolved Raman images of lignified cells were generated, indicating that lignin and cellulose saturated the whole lignified cells, pectin mainly located in the cell corner, and the parenchyma cells contained little lignin. In addition, both phloroglucinol-HCl staining and autofluorescence analysis confirmed the results of lignin distribution of Raman microscopic analysis. CONCLUSIONS A procedure for the simultaneous visualization of the main components of the flesh cells without labeling by high-resolution Raman microspectroscopy has been established. With Raman microscopic imaging technique, we can add a microscopic level to cell compositions, essential for a detailed molecular understanding of loquat lignification. Such method can be further used to chemically monitor the textural changes during the ripening process or postharvest storage of other fruits and vegetables.
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Affiliation(s)
- Nan Zhu
- College of Agriculture and Biotechnology, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth/Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058 People’s Republic of China
| | - Di Wu
- College of Agriculture and Biotechnology, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth/Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058 People’s Republic of China
| | - Kunsong Chen
- College of Agriculture and Biotechnology, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth/Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou, 310058 People’s Republic of China
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Ling Z, Chen S, Zhang X, Xu F. Exploring crystalline-structural variations of cellulose during alkaline pretreatment for enhanced enzymatic hydrolysis. BIORESOURCE TECHNOLOGY 2017; 224:611-617. [PMID: 27816348 DOI: 10.1016/j.biortech.2016.10.064] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/19/2016] [Accepted: 10/20/2016] [Indexed: 05/24/2023]
Abstract
The study aimed to explore the crystallinity and crystalline structure of alkaline pretreated cellulose. The enzymatic hydrolysis followed by pretreatment was conducted for measuring the efficiency of sugar conversion. For cellulose Iβ dominated samples, alkaline pretreatment (<8wt%) caused increased cellulose crystallinity and depolymerized hemicelluloses, that were superimposed to affect the enzymatic conversion to glucose. Varying crystallite sizes and lattice spacings indicated the separation of cellulose crystals during mercerization (8-12wt% NaOH). Completion of mercerization was proved under higher alkaline concentration (14-18wt% NaOH), leading to distortion of crystalline cellulose to some extent. Cellulose II crystallinity showed a stimulative impact on enzymatic hydrolysis due to the weakened hydrophobic interactions within cellulose chains. The current study may provide innovative explanations for enhanced enzymatic digestibility of alkaline pretreated lignocellulosic materials.
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Affiliation(s)
- Zhe Ling
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Sheng Chen
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Xun Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Feng Xu
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
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Kim JE, Lee JW. Improved Ethanol Production from Deacetylated Yellow Poplar (Liriodendron tulipifera) by Detoxification of Hydrolysate and Semi-SSF. KOREAN CHEMICAL ENGINEERING RESEARCH 2016. [DOI: 10.9713/kcer.2016.54.4.494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Ji Z, Zhang X, Ling Z, Sun RC, Xu F. Tissue specific response of Miscanthus×giganteus to dilute acid pretreatment for enhancing cellulose digestibility. Carbohydr Polym 2016; 154:247-56. [PMID: 27577916 DOI: 10.1016/j.carbpol.2016.06.086] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 10/21/2022]
Abstract
The recalcitrance in grasses varies according to cell type and tissue. In this study, dilute acid pretreatment was performed on Miscanthus×giganteus internodes that include rind and pith regions which showing heterogeneous structural and chemical changes. Pretreatment on pith effectively hydrolyzed 73.33% hemicelluloses and separated cohesive cell walls from the compound middle lamella due to lignin migration. Lignin droplets with an average diameter of 49.5±29.3nm were concurrently coalesced on wall surface, that in turn exposed more microfibrils deep in walls to be enzymatically hydrolyzed reaching 82.55%. By contrast, the rind with a relatively intergrated cell structure was covered by larger lignin droplets (101.2±44.1nm) and filled with inaccessible microfibrils limiting enzymatic sacchrification (31.50%). Taken together, the cellulose digestibility of biomass was not majorly influenced by cellulose crystallinity, while it was strongly correlated with the positive effects of hemicelluloses degradation, lignin redistribution, cellulose exposure and loosening cell wall structure.
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Affiliation(s)
- Zhe Ji
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China; College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Xun Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Zhe Ling
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Run-Cang Sun
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China
| | - Feng Xu
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China; Shandong Key Laboratory of Pulping and Papermaking Engineering, Qilu University of Technology, Jinan 250353, China.
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Chen S, Zhang X, Ling Z, Ji Z, Ramarao BV, Ramaswamy S, Xu F. Probing and visualizing the heterogeneity of fiber cell wall deconstruction in sugar maple (Acer saccharum) during liquid hot water pretreatment. RSC Adv 2016. [DOI: 10.1039/c6ra18333f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The S2 layer was differentiated into heavy-damaged region with more polysaccharides removed and relatively intact light-damaged region after LHW pretreatment.
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Affiliation(s)
- Sheng Chen
- Beijing Key Laboratory of Lignocellulosic Chemistry
- Beijing Forestry University
- Beijing 100083
- China
| | - Xun Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry
- Beijing Forestry University
- Beijing 100083
- China
| | - Zhe Ling
- Beijing Key Laboratory of Lignocellulosic Chemistry
- Beijing Forestry University
- Beijing 100083
- China
| | - Zhe Ji
- College of Chemistry and Molecular Engineering
- Qingdao University of Science and Technology
- Qingdao
- China
| | - Bandaru V. Ramarao
- Department of Paper and Bioprocess Engineering
- SUNY College of Environmental Science and Forestry
- Syracuse
- USA
| | - Shri Ramaswamy
- Department of Bioproducts and Biosystems Engineering
- University of Minnesota
- Saint Paul
- USA
| | - Feng Xu
- Beijing Key Laboratory of Lignocellulosic Chemistry
- Beijing Forestry University
- Beijing 100083
- China
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Li HY, Chen X, Wang CZ, Sun SN, Sun RC. Evaluation of the two-step treatment with ionic liquids and alkali for enhancing enzymatic hydrolysis of Eucalyptus: chemical and anatomical changes. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:166. [PMID: 27499809 PMCID: PMC4974680 DOI: 10.1186/s13068-016-0578-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/27/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND The biomass recalcitrance resulting from its chemical compositions and physical structures impedes the conversion of biomass into fermentable sugars. Pretreatment is a necessary procedure to increase the cellulase accessibility for bioconversion of lignocelluloses into bioethanol. Alternatively, ionic liquids, a series of promising solvents, provide unique opportunities for pretreating a wide range of lignocellulosic materials. In this study, a two-step treatment including ionic liquids pretreatment and successive alkali fractionations was performed on Eucalyptus to achieve a high enzymatic digestibility. The compositional and structural changes of Eucalyptus cell walls and their possible effect on saccharification ratio were comprehensively investigated. RESULTS After the ionic liquids pretreatment, the cell walls became loose and even swelled, accompanying with the decrease of cellulose crystallinity. As compared to the simplex ionic liquids pretreatment, the integrated process resulted in the significant removal of hemicelluloses and lignin, enhancing the disruption of the cell walls and increasing the exposure of cellulose, which led to a higher conversion of cellulose to glucose. The glucose yield of Eucalyptus underwent the combination of [Bmim]OAc and alkali treatments reached the maximum (90.53 %), which was 6.6 times higher than that of the untreated Eucalyptus. The combination of chemical compositions and physical structure of Eucalyptus affected the efficiency of cellulose enzymatic hydrolysis. Especially, the changes of cellulose crystallinity played a major role in enhancing the enzymatic digestibility of Eucalyptus in this study. CONCLUSIONS The two-step treatment with ionic liquids pretreatment and successive alkali fractionation can be considered as a promising method to improve the conversion of cellulose to glucose. The detailed information obtained about chemical and anatomical changes was helpful to understand the underlying mechanism of the integrated treatment process acting on Eucalyptus for enhancing enzymatic digestibility.
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Affiliation(s)
- Han-Yin Li
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083 China
| | - Xue Chen
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083 China
| | - Chen-Zhou Wang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083 China
| | - Shao-Ni Sun
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083 China
| | - Run-Cang Sun
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083 China
- State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640 China
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