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Zhang W, Diao C, Wang L. Degradation of lignin in different lignocellulosic biomass by steam explosion combined with microbial consortium treatment. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:55. [PMID: 36997991 PMCID: PMC10064694 DOI: 10.1186/s13068-023-02306-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 03/24/2023] [Indexed: 04/01/2023]
Abstract
The difficulty of degrading lignin is the main factor limiting the high-value conversion process of lignocellulosic biomass. The biodegradation of lignin has attracted much attention because of its strong environmental friendliness, but it still faces some dilemmas such as slow degradation rate and poor adaptability. The microbial consortia with high lignin degradation efficiency and strong environmental adaptability were obtained in our previous research. To further increase the lignin degradation efficiency, this paper proposes a composite treatment technology of steam explosion combined with microbial consortium degradation to treat three kinds of biomass. We measured the lignin degradation efficiency, selectivity value (SV) and enzymatic saccharification efficiency. The structural changes of the biomass materials and microbial consortium structure were also investigated. The experimental results showed that after 1.6 MPa steam explosion treatment, the lignin degradation efficiency of the eucalyptus root reached 35.35% on the 7th days by microbial consortium. At the same time, the lignin degradation efficiency of the bagasse and corn straw treated by steam explosion followed by microbial biotreatment was 37.61-44.24%, respectively, after only 7 days of biotreatment. The microbial consortium also showed strong selectivity degradation to lignin. The composite treatment technology can significantly improve the enzymatic saccharification efficiency. Saccharomycetales, Ralstonia and Pseudomonadaceae were the dominant microorganisms in the biomass degradation systems. It was proved that the combined treatment technology of steam explosion and microbial consortium degradation could overcome the drawbacks of traditional microbial pretreatment technology, and can facilitate the subsequent high-value conversion of lignocellulose.
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Affiliation(s)
- Wen Zhang
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310015, Zhejiang, China.
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Zhejiang Shuren University, Hangzhou, 310015, Zhejiang, China.
| | - Chenyang Diao
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310015, Zhejiang, China
| | - Lei Wang
- School of Engineering, Westlake University, Hangzhou, 310024, Zhejiang, China.
- Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou, 310024, Zhejiang, China.
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Wu J, Ebadian M, Kim KH, Kim CS, Saddler J. The use of steam pretreatment to enhance pellet durability and the enzyme-mediated hydrolysis of pellets to fermentable sugars. BIORESOURCE TECHNOLOGY 2022; 347:126731. [PMID: 35074465 DOI: 10.1016/j.biortech.2022.126731] [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: 12/10/2021] [Revised: 01/13/2022] [Accepted: 01/15/2022] [Indexed: 06/14/2023]
Abstract
Although densified wood pellets are an attractive biomass feedstock for bioenergy and biofuels production, partly due to their ease of transport, their friability and hygroscopic nature (attraction of moisture) have proven problematic in terms of storage and handling. Pre-steaming the biomass was shown to reduce the need for size reduction, significantly increasing pellet durability by relocating the plant cell wall lignin to the fibre surface and consequently enhancing binding between particles. Although steam pretreatment has been shown to facilitate enzyme-mediated hydrolysis of biomass, by increasing cellulose accessibility, drying and pelletization partially impeded enzymatic hydrolysis. However, the incorporation of alkaline deacetylation or neutral sulfonation step prior to pre-steaming was shown to mitigate many of the negative effects of drying. Although drying and pelletization did not significantly impact the redistribution of lignin, a mild mechanical refining step was shown to further enhance the hydrolysis of the cellulose component of the pelletized biomass.
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Affiliation(s)
- Jie Wu
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver BC V6T 1Z4, Canada
| | - Mahmood Ebadian
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver BC V6T 1Z4, Canada
| | - Kwang Ho Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Chang Soo Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jack Saddler
- Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver BC V6T 1Z4, Canada.
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Xu C, Li J, Yuan Q, Liu N, Zhang X, Wang P, Gao Y. Effects of different fermentation assisted enzyme treatments on the composition, microstructure and physicochemical properties of wheat straw used as a substitute for peat in nursery substrates. BIORESOURCE TECHNOLOGY 2021; 341:125815. [PMID: 34454234 DOI: 10.1016/j.biortech.2021.125815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
To solve the central problems caused by traditional composting treatments, such as long-time consumption and poor regulation effects, this study used three fermentation methods and four enzymes to develop rapid and directional regulation methods to convert wheat straw into a suitable substrate. The results showed that the mixed anaerobic method led to better pH (4.39-5.75) and EC values (1.27-1.89 mS/cm) in the straw substrates, while the aerobic method retained more nutrients and increased lignin and cellulose contents by 5.07-8.04% and 1.52-3.32%. The cellulase mixed with hemicellulase or laccase treatments all increased the crystallinity by 0.45-7.23%. The TG/DTG results showed that all treatments decreased the initial straw glass transition temperature, particularly when using the mixed anaerobic method, with decreases of 10.63-25.48 °C. Overall, mixed anaerobic fermentation and multiple enzymes, including cellulase, have been suggested as alternative biological modification methods for straw substrates.
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Affiliation(s)
- Chao Xu
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China
| | - Jun Li
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China
| | - Qiaoxia Yuan
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China.
| | - Nian Liu
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China
| | - Xin Zhang
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China
| | - Panpan Wang
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, China
| | - Yong Gao
- Wuhan Optics Valley Bluefire New Energy Co., Ltd., Wuhan 430000, China
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Ballmann P, Lightfoot J, Müller M, Dröge S, Prade R. Redesigning the Aspergillus nidulans xylanase regulatory pathway to enhance cellulase production with xylose as the carbon and inducer source. Microb Cell Fact 2019; 18:193. [PMID: 31699093 PMCID: PMC6839167 DOI: 10.1186/s12934-019-1243-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/24/2019] [Indexed: 11/10/2022] Open
Abstract
Background Biomass contains cellulose (C6-sugars), hemicellulose (C5-sugars) and lignin. Biomass ranks amongst the most abundant hydrocarbon resources on earth. However, biomass is recalcitrant to enzymatic digestion by cellulases. Physicochemical pretreatment methods make cellulose accessible but partially destroy hemicellulose, producing a C5-sugar-rich liquor. Typically, digestion of pretreated LCB is performed with commercial cellulase preparations, but C5-sugars could in principle be used for “on site” production of cellulases by genetically engineered microorganism, thereby reducing costs. Results Here we report a succession of genetic interventions in Aspergillus nidulans that redesign the natural regulatory circuitry of cellulase genes in such a way that recombinant strains use C5-sugar liquors (xylose) to grow a vegetative tissue and simultaneously accumulate large amounts of cellulases. Overexpression of XlnR showed that under xylose-induction conditions only xylanase C was produced. XlnR overexpression strains were constructed that use the xynCp promoter to drive the production of cellobiohydrolases, endoglucanases and β-glucosidase. All five cellulases accumulated at high levels when grown on xylose. Production of cellulases in the presence of pretreated-biomass C5-sugar liquors was investigated, and cellulases accumulated to much higher enzyme titers than those obtained for traditional fungal cell factories with cellulase-inducing substrates. Conclusions By replacing expensive substrates with a cheap by-product carbon source, the use of C5-sugar liquors directly derived from LCB pretreatment processes not only reduces enzyme production costs, but also lowers operational costs by eliminating the need for off-site enzyme production, purification, concentration, transport and dilution.
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Affiliation(s)
- Patrick Ballmann
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Jorge Lightfoot
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Michael Müller
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Stephan Dröge
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Rolf Prade
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA.
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Tang S, Liu W, Huang C, Lai C, Fan Y, Yong Q. Improving the enzymatic hydrolysis of larch by coupling water pre-extraction with alkaline hydrogen peroxide post-treatment and adding enzyme cocktail. BIORESOURCE TECHNOLOGY 2019; 285:121322. [PMID: 30965281 DOI: 10.1016/j.biortech.2019.121322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
Soluble arabinogalactan (AG) in larch leads to reagent waste during its biorefining using oxidative pretreatment strategies. A two-stage pretreatment of water pre-extraction followed by alkaline hydrogen peroxide (AHP) pretreatment was investigated to more efficiently convert larch cellulose into glucose, while also obtaining a value-added AG product stream. The results showed that water pre-extraction increases the lignin selectivity of both NaOH and H2O2 reagents, translating to improved lignin removal and enzymatic hydrolysis yields. This was found to be related to cellulose accessibility alongside the effective consumption of the reagents. Moreover, the addition of mannanase also significantly enhanced enzymatic digestibility of pretreated solid from 81.0% to 97.7% (4% H2O2 charge and 180 °C) when 40 U/g mannanase was supplemented with 20 FPU/g cellulase. In all, it was demonstrated that coupling mannanase with cellulase could improve larch's enzymatic digestibility and overall viability for biorefining processes.
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Affiliation(s)
- Shuo Tang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Wanying Liu
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Caoxing Huang
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Chenhuan Lai
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Yimin Fan
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China
| | - Qiang Yong
- Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China; Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing 210037, People's Republic of China.
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Xu H, Che X, Ding Y, Kong Y, Li B, Tian W. Effect of crystallinity on pretreatment and enzymatic hydrolysis of lignocellulosic biomass based on multivariate analysis. BIORESOURCE TECHNOLOGY 2019; 279:271-280. [PMID: 30738353 DOI: 10.1016/j.biortech.2018.12.096] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 12/24/2018] [Accepted: 12/26/2018] [Indexed: 05/26/2023]
Abstract
In this work, multivariate data analysis was employed to correlate variables of pretreatment process of lignocellulosic biomass. Principal component analysis and partial least square methods were performed to get the inner-relationship and data interpretation between the crystallinity and other parameters of mechanical refining-assisted sodium hydroxide pretreatment followed by enzymatic saccharification of corn stover. The PCA and PLS models showed that Sodium hydroxide dosage, mechanical refining treatment, lignin removal rate and crystallinity had close inner-related relationship with the efficiency of pretreatment and enzymolysis. Alkaline reaction and mechanical refining treatment had strong influence on the crystallinity. Multivariate data analysis revealed that pretreated corn stover samples with lower crystallinity were more easily hydrolyzed by enzyme and could get more final reducing sugar. This work could offer a new methodology to get further understanding of effect of crystallinity on the crop residue lignocellulosic biomass conversion process.
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Affiliation(s)
- Huanfei Xu
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China; CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; PCC & Laboratory of Wood and Paper Chemistry, Ǻbo Akademi University, Turku FI-20500, Finland; state Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
| | - Xinpeng Che
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China; CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; state Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
| | - Yu Ding
- College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
| | - Yi Kong
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China; state Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
| | - Bin Li
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China
| | - Wende Tian
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China; state Key Laboratory Base for Eco-Chemical Engineering in College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China
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Gaur R, Semwal S, Raj T, Yadav Lamba B, Ramu E, Gupta RP, Kumar R, Puri SK. Intensification of steam explosion and structural intricacies impacting sugar recovery. BIORESOURCE TECHNOLOGY 2017; 241:692-700. [PMID: 28614764 DOI: 10.1016/j.biortech.2017.05.208] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
Dilute acid (DA) pretreatment at pilot level failed for cotton stalk (CS) due to the technical issues posed by its inherent nature. Reasonable glucan conversion has been reported via two-stage pretreatment but adds on to the process cost. Proposed herewith is a single-stage steam explosion (SE) process preceded by water extraction resulting in high sugar recovery from CS. Raising the extraction temperature to 80°C increased the glucan conversion from 37.9 to 52.4%. Further improvement up to 68.4% was achieved when DA was incorporated during the room temperature extraction. LC-MS revealed the formation of xylo-oligomers limiting the glucan conversion in proportion to the length of xylo-oligomers. Varying extraction conditions induced structural alterations in biomass after SE evident by compositional analysis, Infrared Spectroscopy, X-Ray Diffraction and Scanning Electron Microscopy. Overall glucose recovery, i.e. 75.8-76.7% with and without DA extraction respectively was achieved.
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Affiliation(s)
- Ruchi Gaur
- DBT-IOC Center for Advanced Bioenergy Research, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India
| | - Surbhi Semwal
- DBT-IOC Center for Advanced Bioenergy Research, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India
| | - Tirath Raj
- DBT-IOC Center for Advanced Bioenergy Research, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India; College of Engineering, Department of Chemistry, University of Petroleum & Energy Studies, Village & P.O Bidholi, Prem Nagar, Dehradun (UA) 248007, India
| | - Bhawna Yadav Lamba
- College of Engineering, Department of Chemistry, University of Petroleum & Energy Studies, Village & P.O Bidholi, Prem Nagar, Dehradun (UA) 248007, India
| | - E Ramu
- Analytical Division, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India
| | - Ravi P Gupta
- DBT-IOC Center for Advanced Bioenergy Research, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India
| | - Ravindra Kumar
- DBT-IOC Center for Advanced Bioenergy Research, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India.
| | - Suresh K Puri
- DBT-IOC Center for Advanced Bioenergy Research, Indian Oil Corporation, R&D Centre, Sector-13, Faridabad, Haryana 121007, India
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Pielhop T, Amgarten J, Studer MH, von Rohr PR. Pilot-scale steam explosion pretreatment with 2-naphthol to overcome high softwood recalcitrance. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:130. [PMID: 28529543 PMCID: PMC5437563 DOI: 10.1186/s13068-017-0816-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/02/2017] [Indexed: 05/11/2023]
Abstract
BACKGROUND Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. It is however not effective for overcoming the extremely high recalcitrance of softwood to biochemical conversion. Recent fundamental research in small-scale liquid hot water pretreatment has shown, though, that the addition of a carbocation scavenger like 2-naphthol can prevent lignin repolymerization and thus enhance the enzymatic digestibility of softwood cellulose. This work studies the technical application potential of this approach in a larger steam explosion pilot plant for surmounting softwood recalcitrance. RESULTS The addition of 35.36 g 2-naphthol to the steam explosion pretreatment of 1.5 kg spruce wood chips allowed to considerably enhance the enzymatic cellulose digestibility. Different ways of adding the solid 2-naphthol to steam pretreatment were tested. Mixing with the biomass before pretreatment could enhance digestibility by up to 55% compared to control experiments. Impregnation of the biomass with 2-naphthol was yet more effective. Acetone and ethanol were tested to dissolve 2-naphthol and impregnate the biomass. The solvents were then removed again by evaporation before the pretreatment. The impregnation allowed to enhance digestibility by up to 179 and 192%, respectively. A comparison to prevalent acid-catalyzed steam explosion pretreatments for softwood revealed that the scavenger approach allows for obtaining exceptionally high yields in enzymatic hydrolysis. The biomass impregnation with 2-naphthol even renders a complete enzymatic cellulose conversion possible, which is remarkable for a softwood pretreatment not removing lignin. Steam pretreatment experiments without explosive decompression revealed that the enhancing effects of the explosion and the scavenger complement each other well. The explosion enhances the accessibility of the cellulose while the use of the scavenger reduces particularly the deactivation of enzymes. CONCLUSIONS This is the first study to show that a carbocation scavenger in steam pretreatment can enhance the enzymatic digestibility of lignocellulosic biomass. The approach opens up a novel possibility for overcoming the high softwood recalcitrance in a process that does not require an acid catalyst or the removal of lignin from the biomass.
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Affiliation(s)
- Thomas Pielhop
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Janick Amgarten
- Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Michael H. Studer
- School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Länggasse 85, 3052 Zollikofen, Switzerland
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Seidel CM, Pielhop T, Studer MH, Rudolf von Rohr P. The influence of the explosive decompression in steam-explosion pretreatment on the enzymatic digestibility of different biomasses. Faraday Discuss 2017; 202:269-280. [DOI: 10.1039/c7fd00066a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the production of second generation biofuels from lignocellulosic biomass, pretreatment of the biomass feedstock is necessary to overcome its recalcitrance in order to gain fermentable sugars. Due to many reasons, steam-explosion pretreatment is currently the most commonly used pretreatment method for lignocellulosic biomass on a commercial scale [S. Brethauer and M. H. Studer, CHIMIA, 2015, 69, 572–581]. In contrast to others, we showed that the explosive decompression at the end of this pretreatment step can have a positive influence on the enzymatic digestibility of softwood, especially in combination with high enzyme dosages [T. Pielhop, et al., Biotechnology for Biofuels, 2016, 9, 152]. In this study, the influence of the explosive decompression on the enzymatic digestibility of hardwood and herbaceous plants was systematically studied. Beech and corn stover were pretreated under different pretreatment conditions and enzymatically hydrolysed with different enzyme dosages. The maximum enhancement of the digestibility of corn stover was 16.53% after a 2.5 min pretreatment step at 15 barg steam pressure. For beech, a maximum relative enhancement of 58.29% after a 10 min pretreatment step at 15 barg steam pressure could be reached. With this, we show that the explosive decompression can also enhance the enzymatic cellulose digestibility of hardwood and herbaceous plants.
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Affiliation(s)
| | - Thomas Pielhop
- Institute of Process Engineering
- ETH Zurich
- 8092 Zurich
- Switzerland
| | - Michael H. Studer
- School of Agricultural
- Forest and Food Sciences
- Bern University of Applied Sciences
- 3052 Zollikofen
- Switzerland
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Zheng Y, Shi J, Tu M, Cheng YS. Principles and Development of Lignocellulosic Biomass Pretreatment for Biofuels. ADVANCES IN BIOENERGY 2017. [DOI: 10.1016/bs.aibe.2017.03.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Pielhop T, Amgarten J, von Rohr PR, Studer MH. Steam explosion pretreatment of softwood: the effect of the explosive decompression on enzymatic digestibility. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:152. [PMID: 27453727 PMCID: PMC4957380 DOI: 10.1186/s13068-016-0567-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/12/2016] [Indexed: 05/02/2023]
Abstract
BACKGROUND Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. The information available about the effect of the explosive decompression on the biochemical conversion is, however, very limited, and no studies prove that the latter is actually enhanced by the explosion. Hence, it is of great value to discern between the effect of the explosion on the one hand and the steaming on the other hand, to identify their particular influences on enzymatic digestibility. RESULTS The effect of the explosive decompression in the steam explosion pretreatment of spruce wood chips on their enzymatic cellulose digestibility was studied systematically. The explosion had a high influence on digestibility, improving it by up to 90 % compared to a steam pretreatment without explosion. Two factors were identified to be essentially responsible for the effect of the explosion on enzymatic digestibility: pretreatment severity and pressure difference of the explosion. A higher pretreatment severity can soften up and weaken the lignocellulose structure more, so that the explosion can better break up the biomass and decrease its particle size, which enhances its digestibility. In particular, increasing the pressure difference of the explosion leads to more defibration, a smaller particle size and a better digestibility. Though differences were found in the micro- and nanostructure of exploded and non-exploded biomass, the only influence of the explosion on digestibility was found to be the macroscopic particle size reduction. Steam explosion treatments with a high severity and a high pressure difference of the explosion lead to a comparatively high cellulose digestibility of the-typically very recalcitrant-softwood biomass. CONCLUSIONS This is the first study to show that explosion can enhance the enzymatic digestibility of lignocellulosic biomass. If the enhancing effect of the explosion is thoroughly exploited, even very recalcitrant biomass like softwood can be made enzymatically digestible.
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Affiliation(s)
- Thomas Pielhop
- />Transport Processes and Reactions Laboratory, Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Janick Amgarten
- />Transport Processes and Reactions Laboratory, Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Philipp Rudolf von Rohr
- />Transport Processes and Reactions Laboratory, Institute of Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Michael H. Studer
- />Laboratory for Bioenergy and Biochemicals, School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Länggasse 85, 3052 Zollikofen, Switzerland
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Pan SY, Lin YJ, Snyder SW, Ma HW, Chiang PC. Development of Low-Carbon-Driven Bio-product Technology Using Lignocellulosic Substrates from Agriculture: Challenges and Perspectives. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s40518-015-0040-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Huang C, He J, Wang Y, Min D, Yong Q. Associating cooking additives with sodium hydroxide to pretreat bamboo residues for improving the enzymatic saccharification and monosaccharides production. BIORESOURCE TECHNOLOGY 2015; 193:142-149. [PMID: 26133470 DOI: 10.1016/j.biortech.2015.06.073] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 06/04/2023]
Abstract
Cooking additive pulping technique is used in kraft mill to increase delignification degree and pulp yield. In this work, cooking additives were firstly applied in the sodium hydroxide pretreatment for improving the bioconversion of bamboo residues to monosaccharides. Meanwhile, steam explosion and sulfuric acid pretreatments were also carried out on the sample to compare their impacts on monosaccharides production. Results indicated that associating anthraquinone with sodium hydroxide pretreatment showed the best performance in improving the original carbohydrates recovery, delignification, enzymatic saccharification, and monosaccharides production. After consecutive pretreatment and enzymatic saccharification process, 347.49 g, 307.48 g, 142.93 g, and 87.15 g of monosaccharides were released from 1000 g dry bamboo residues pretreated by sodium hydroxide associating with anthraquinone, sodium hydroxide, steam explosion and sulfuric acid, respectively. The results suggested that associating cooking additive with sodium hydroxide is an effective pretreatment for bamboo residues to enhance enzymatic saccharification for monosaccharides production.
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Affiliation(s)
- Caoxing Huang
- College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Juan He
- College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Yan Wang
- College of Light Industry Science and Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Douyong Min
- College of Light Industry Science and Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Qiang Yong
- College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
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15
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Structural changes of Salix miyabeana cellulose fibres during dilute-acid steam explosion: Impact of reaction temperature and retention time. Carbohydr Polym 2015; 119:8-17. [DOI: 10.1016/j.carbpol.2014.11.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 11/11/2014] [Accepted: 11/16/2014] [Indexed: 11/21/2022]
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16
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Kang Y, Realff MJ, Sohn M, Lee JH, Bommarius AS. An effective chemical pretreatment method for lignocellulosic biomass with substituted imidazoles. Biotechnol Prog 2014; 31:25-34. [DOI: 10.1002/btpr.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/29/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Yuzhi Kang
- School of Chemical and Biomolecular Engineering; Georgia Inst. of Technology; Atlanta GA 30332
| | - Matthew J. Realff
- School of Chemical and Biomolecular Engineering; Georgia Inst. of Technology; Atlanta GA 30332
| | - Minjeong Sohn
- School of Chemical and Biomolecular Engineering; Georgia Inst. of Technology; Atlanta GA 30332
- School of Chemical and Biomolecular Engineering; Korean Advanced Inst. of Science and Technology; Daejeon South Korea
| | - Jay H. Lee
- School of Chemical and Biomolecular Engineering; Georgia Inst. of Technology; Atlanta GA 30332
- School of Chemical and Biomolecular Engineering; Korean Advanced Inst. of Science and Technology; Daejeon South Korea
| | - Andreas S. Bommarius
- School of Chemical and Biomolecular Engineering; Georgia Inst. of Technology; Atlanta GA 30332
- School of Chemistry and Biochemistry; Georgia Inst. of Technology; Atlanta GA 30332
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17
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Meng X, Ragauskas AJ. Recent advances in understanding the role of cellulose accessibility in enzymatic hydrolysis of lignocellulosic substrates. Curr Opin Biotechnol 2014; 27:150-8. [DOI: 10.1016/j.copbio.2014.01.014] [Citation(s) in RCA: 235] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/08/2014] [Accepted: 01/21/2014] [Indexed: 10/25/2022]
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18
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Lai C, Tu M, Li M, Yu S. Remarkable solvent and extractable lignin effects on enzymatic digestibility of organosolv pretreated hardwood. BIORESOURCE TECHNOLOGY 2014; 156:92-9. [PMID: 24495536 DOI: 10.1016/j.biortech.2014.01.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/06/2014] [Accepted: 01/08/2014] [Indexed: 05/02/2023]
Abstract
Low solvent concentration effect on substrate digestibility of ethanol organosolv pretreated sweetgum was examined. Surprisingly, lower ethanol concentration in organosolv pretreatments resulted in faster initial rates and higher 72h hydrolysis yields in pretreated substrates. A strong correlation (r(2)=0.96) between pretreatment combined severity factor and residual xylan/glucan ratio was observed. The residual xylan/glucan ratio was associated with the initial hydrolysis rate closely. Furthermore, it was found that preserving extractable lignin in the pretreated substrates could improve enzymatic hydrolysis yield by 33%. This has an important implication in reducing the pretreatment and enzyme cost, because the typical solvent washing after pretreatment could be eliminated and preserving extractable lignin could reduce enzyme loading. Finally, we observed that xylan removal by xylanase could improve the initial rate by 53% and increase the 72h hydrolysis yield by 21%. The extractable lignin precipitation on pretreated substrates increased the 72h hydrolysis yield by 10%.
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Affiliation(s)
- Chenhuan Lai
- College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China; Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States
| | - Maobing Tu
- Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States.
| | - Mi Li
- Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States
| | - Shiyuan Yu
- College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China
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