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Tafoukt D, Soric A, Sigoillot JC, Ferrasse JH. Determination of kinetics and heat of hydrolysis for non-homogenous substrate by isothermal calorimetry. Bioprocess Biosyst Eng 2017; 40:643-650. [PMID: 28062914 DOI: 10.1007/s00449-016-1728-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/13/2016] [Indexed: 10/20/2022]
Abstract
The competitiveness of the second-generation bioethanol by biotechnological process requires an effective and quantitative control of biochemical reactions. In this study, the potential of isothermal calorimetry technique to measure heat and kinetics of a non-homogeneous substrate enzymatic hydrolysis is intended. Using this technique, optimum temperature of the enzymes used for lignocellulosic molecules hydrolysis was determined. Thus, the amount of substrate-to-enzyme ratio was highlighted as an important parameter of the hydrolysis yield. Furthermore, a new enzymes' cocktail efficiency consisting of a mix of cellulases and cellobiose dehydrogenase (CDH) was qualified by this technique. The results showed that this cocktail allowed the production of a high amount of gluconic acid that could improve the attractiveness of these second-generation biofuels. From the set of experiments, the hydrolysis heat of wheat straw was derived and a meaningful value of -32.2 ± 3.2 J g-1 (gram reducing sugars product) is calculated. Then, isothermal measurements were used to determine kinetic constants of the cellulases and CDH mix on wheat straw. Results showed that this enzyme cocktail has an optimal rate at 45 °C in the range of temperatures tested (40-55 °C).
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Affiliation(s)
- D Tafoukt
- Aix Marseille Univ, CNRS, Centrale Marseille, M2P2, Marseille, France
| | - A Soric
- Aix Marseille Univ, CNRS, Centrale Marseille, M2P2, Marseille, France
| | | | - J-H Ferrasse
- Aix Marseille Univ, CNRS, Centrale Marseille, M2P2, Marseille, France.
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Vargas F, Domínguez E, Vila C, Rodríguez A, Garrote G. Agricultural residue valorization using a hydrothermal process for second generation bioethanol and oligosaccharides production. BIORESOURCE TECHNOLOGY 2015; 191:263-270. [PMID: 26000836 DOI: 10.1016/j.biortech.2015.05.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/11/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
In the present work, the hydrothermal valorization of an abundant agricultural residue has been studied in order to look for high added value applications by means of hydrothermal pretreatment followed by fed-batch simultaneous saccharification and fermentation, to obtain oligomers and sugars from autohydrolysis liquors and bioethanol from the solid phase. Non-isothermal autohydrolysis was applied to barley straw, leading to a solid phase with about a 90% of glucan and lignin and a liquid phase with up to 168 g kg(-1) raw material valuable hemicellulose-derived compounds. The solid phase showed a high enzymatic susceptibility (up to 95%). It was employed in the optimization study of the fed-batch simultaneous saccharification and fermentation, carried out at high solids loading, led up to 52 g ethanol/L (6.5% v/v).
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Affiliation(s)
- Fátima Vargas
- Department of Chemical Engineering, Faculty of Science, University of Cordoba, Campus of Rabanales, Marie-Curie Building (C-3), N-IV Road, km. 396, 14071 Cordoba, Spain
| | - Elena Domínguez
- Department of Chemical Engineering, Faculty of Science, University of Vigo (Campus Ourense), As Lagoas, 32004 Ourense, Spain; CITI (Centro de Investigación, Transferencia e Innovación), University of Vigo, Tecnopole, San Cibrao das Viñas, Ourense, Spain
| | - Carlos Vila
- Department of Chemical Engineering, Faculty of Science, University of Vigo (Campus Ourense), As Lagoas, 32004 Ourense, Spain; CITI (Centro de Investigación, Transferencia e Innovación), University of Vigo, Tecnopole, San Cibrao das Viñas, Ourense, Spain
| | - Alejandro Rodríguez
- Department of Chemical Engineering, Faculty of Science, University of Cordoba, Campus of Rabanales, Marie-Curie Building (C-3), N-IV Road, km. 396, 14071 Cordoba, Spain
| | - Gil Garrote
- Department of Chemical Engineering, Faculty of Science, University of Vigo (Campus Ourense), As Lagoas, 32004 Ourense, Spain; CITI (Centro de Investigación, Transferencia e Innovación), University of Vigo, Tecnopole, San Cibrao das Viñas, Ourense, Spain.
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5
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Sykes RW, Gjersing EL, Foutz K, Rottmann WH, Kuhn SA, Foster CE, Ziebell A, Turner GB, Decker SR, Hinchee MAW, Davis MF. Down-regulation of p-coumaroyl quinate/shikimate 3'-hydroxylase (C3'H) and cinnamate 4-hydroxylase (C4H) genes in the lignin biosynthetic pathway of Eucalyptus urophylla × E. grandis leads to improved sugar release. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:128. [PMID: 26312068 PMCID: PMC4550073 DOI: 10.1186/s13068-015-0316-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/13/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND Lignocellulosic materials provide an attractive replacement for food-based crops used to produce ethanol. Understanding the interactions within the cell wall is vital to overcome the highly recalcitrant nature of biomass. One factor imparting plant cell wall recalcitrance is lignin, which can be manipulated by making changes in the lignin biosynthetic pathway. In this study, eucalyptus down-regulated in expression of cinnamate 4-hydroxylase (C4H, EC 1.14.13.11) or p-coumaroyl quinate/shikimate 3'-hydroxylase (C3'H, EC 1.14.13.36) were evaluated for cell wall composition and reduced recalcitrance. RESULTS Eucalyptus trees with down-regulated C4H or C3'H expression displayed lowered overall lignin content. The control samples had an average of 29.6 %, the C3'H reduced lines had an average of 21.7 %, and the C4H reduced lines had an average of 18.9 % lignin from wet chemical analysis. The C3'H and C4H down-regulated lines had different lignin compositions with average S/G/H ratios of 48.5/33.2/18.3 for the C3'H reduced lines and 59.0/39.8/1.2 for the C4H reduced lines, compared to the control with 65.9/33.2/1.0. Both the C4H and C3'H down-regulated lines had reduced recalcitrance as indicated by increased sugar release as determined using enzymatic conversion assays utilizing both no pretreatment and a hot water pretreatment. CONCLUSIONS Lowering lignin content rather than altering sinapyl alcohol/coniferyl alcohol/4-coumaryl alcohol ratios was found to have the largest impact on reducing recalcitrance of the transgenic eucalyptus variants. The development of lower recalcitrance trees opens up the possibility of using alternative pretreatment strategies in biomass conversion processes that can reduce processing costs.
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Affiliation(s)
- Robert W. Sykes
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401-3393 USA
| | - Erica L. Gjersing
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401-3393 USA
| | - Kirk Foutz
- />ArborGen Inc., 2011 Broadbank Ct., Ridgeville, SC 29472 USA
| | | | - Sean A. Kuhn
- />ArborGen Inc., 2011 Broadbank Ct., Ridgeville, SC 29472 USA
| | - Cliff E. Foster
- />Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Angela Ziebell
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401-3393 USA
| | - Geoffrey B. Turner
- />Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401-3393 USA
| | - Stephen R. Decker
- />Biosciences Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401-3393 USA
| | | | - Mark F. Davis
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401-3393 USA
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Xu N, Zhang W, Ren S, Liu F, Zhao C, Liao H, Xu Z, Huang J, Li Q, Tu Y, Yu B, Wang Y, Jiang J, Qin J, Peng L. Hemicelluloses negatively affect lignocellulose crystallinity for high biomass digestibility under NaOH and H2SO4 pretreatments in Miscanthus. BIOTECHNOLOGY FOR BIOFUELS 2012; 5:58. [PMID: 22883929 PMCID: PMC3462114 DOI: 10.1186/1754-6834-5-58] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 07/18/2012] [Indexed: 05/02/2023]
Abstract
BACKGROUND Lignocellulose is the most abundant biomass on earth. However, biomass recalcitrance has become a major factor affecting biofuel production. Although cellulose crystallinity significantly influences biomass saccharification, little is known about the impact of three major wall polymers on cellulose crystallization. In this study, we selected six typical pairs of Miscanthus samples that presented different cell wall compositions, and then compared their cellulose crystallinity and biomass digestibility after various chemical pretreatments. RESULTS A Miscanthus sample with a high hemicelluloses level was determined to have a relatively low cellulose crystallinity index (CrI) and enhanced biomass digestibility at similar rates after pretreatments of NaOH and H2SO4 with three concentrations. By contrast, a Miscanthus sample with a high cellulose or lignin level showed increased CrI and low biomass saccharification, particularly after H2SO4 pretreatment. Correlation analysis revealed that the cellulose CrI negatively affected biomass digestion. Increased hemicelluloses level by 25% or decreased cellulose and lignin contents by 31% and 37% were also found to result in increased hexose yields by 1.3-times to 2.2-times released from enzymatic hydrolysis after NaOH or H2SO4 pretreatments. The findings indicated that hemicelluloses were the dominant and positive factor, whereas cellulose and lignin had synergistic and negative effects on biomass digestibility. CONCLUSIONS Using six pairs of Miscanthus samples with different cell wall compositions, hemicelluloses were revealed to be the dominant factor that positively determined biomass digestibility after pretreatments with NaOH or H2SO4 by negatively affecting cellulose crystallinity. The results suggested potential approaches to the genetic modifications of bioenergy crops.
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Affiliation(s)
- Ning Xu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
- Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, Huaian, 223300, China
| | - Wei Zhang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuangfeng Ren
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Fei Liu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chunqiao Zhao
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Haofeng Liao
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhengdan Xu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jiangfeng Huang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qing Li
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuanyuan Tu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Bin Yu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yanting Wang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jianxiong Jiang
- Department of Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Jingping Qin
- Department of Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Liangcai Peng
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070, China
- Biomass and Bioenergy Research Centre, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
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