251
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Weiss ND, Thygesen LG, Felby C, Roslander C, Gourlay K. Biomass-water interactions correlate to recalcitrance and are intensified by pretreatment: An investigation of water constraint and retention in pretreated spruce using low field NMR and water retention value techniques. Biotechnol Prog 2016; 33:146-153. [DOI: 10.1002/btpr.2398] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/28/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Noah D. Weiss
- Dept. of Geosciences and Natural Resource Management; University of Copenhagen; Copenhagen Denmark
| | | | - Claus Felby
- Dept. of Geosciences and Natural Resource Management; University of Copenhagen; Copenhagen Denmark
| | | | - Keith Gourlay
- Dept. of Forest Products, Biotechnology and Bioenergy; University of British Columbia; Vancouver Canada
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252
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Zuorro A, Maffei G, Lavecchia R. Optimization of enzyme-assisted lipid extraction from Nannochloropsis microalgae. J Taiwan Inst Chem Eng 2016. [DOI: 10.1016/j.jtice.2016.08.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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253
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Jung JH, Altpeter F. TALEN mediated targeted mutagenesis of the caffeic acid O-methyltransferase in highly polyploid sugarcane improves cell wall composition for production of bioethanol. PLANT MOLECULAR BIOLOGY 2016; 92:131-42. [PMID: 27306903 PMCID: PMC4999463 DOI: 10.1007/s11103-016-0499-y] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 05/30/2016] [Indexed: 05/18/2023]
Abstract
Sugarcane (Saccharum spp. hybrids) is a prime crop for commercial biofuel production. Advanced conversion technology utilizes both, sucrose accumulating in sugarcane stems as well as cell wall bound sugars for commercial ethanol production. Reduction of lignin content significantly improves the conversion of lignocellulosic biomass into ethanol. Conventional mutagenesis is not expected to confer reduction in lignin content in sugarcane due to its high polyploidy (x = 10-13) and functional redundancy among homo(eo)logs. Here we deploy transcription activator-like effector nuclease (TALEN) to induce mutations in a highly conserved region of the caffeic acid O-methyltransferase (COMT) of sugarcane. Capillary electrophoresis (CE) was validated by pyrosequencing as reliable and inexpensive high throughput method for identification and quantitative characterization of TALEN mediated mutations. Targeted COMT mutations were identified by CE in up to 74 % of the lines. In different events 8-99 % of the wild type COMT were converted to mutant COMT as revealed by pyrosequencing. Mutation frequencies among mutant lines were positively correlated to lignin reduction. Events with a mutation frequency of 99 % displayed a 29-32 % reduction of the lignin content compared to non-transgenic controls along with significantly reduced S subunit content and elevated hemicellulose content. CE analysis displayed similar peak patterns between primary COMT mutants and their vegetative progenies suggesting that TALEN mediated mutations were faithfully transmitted to vegetative progenies. This is the first report on genome editing in sugarcane. The findings demonstrate that targeted mutagenesis can improve cell wall characteristics for production of lignocellulosic ethanol in crops with highly complex genomes.
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Affiliation(s)
- Je Hyeong Jung
- Agronomy Department, University of Florida, IFAS, PO Box 110300, Gainesville, FL, 32611, USA
- Institute of Life Science and Natural Resources, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Fredy Altpeter
- Agronomy Department, University of Florida, IFAS, PO Box 110300, Gainesville, FL, 32611, USA.
- Plant Molecular and Cellular Biology Program, University of Florida, IFAS, PO Box 110300, Gainesville, FL, 32611, USA.
- Agronomy Department, University of Florida-IFAS, PO Box 103610, Gainesville, FL, 32611, USA.
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254
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Reverse membrane bioreactor: Introduction to a new technology for biofuel production. Biotechnol Adv 2016; 34:954-975. [DOI: 10.1016/j.biotechadv.2016.05.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 04/08/2016] [Accepted: 05/25/2016] [Indexed: 11/22/2022]
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255
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Martins MTB, de Souza WR, da Cunha BADB, Basso MF, de Oliveira NG, Vinecky F, Martins PK, de Oliveira PA, Arenque-Musa BC, de Souza AP, Buckeridge MS, Kobayashi AK, Quirino BF, Molinari HBC. Characterization of sugarcane (Saccharum spp.) leaf senescence: implications for biofuel production. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:153. [PMID: 27453728 PMCID: PMC4957918 DOI: 10.1186/s13068-016-0568-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/12/2016] [Indexed: 05/29/2023]
Abstract
BACKGROUND Second-generation ethanol (2G-bioethanol) uses lignocellulosic feedstocks for ethanol production. Sugarcane is one among the most suitable crops for biofuel production. Its juice is extracted for sugar production, while sugarcane bagasse, straw, and senescing leaves are considered industrial waste. Senescence is the age-dependent deterioration of plant cells, ultimately leading to cell death and completion of the plant life cycle. Because senescing leaves may also be used for biofuel production, understanding the process of natural senescence, including remobilization of nutrients and its effect on cell walls can provide useful information for 2G-bioethanol production from sugarcane leaves. RESULTS The natural senescence process in leaves of the commercial sugarcane cultivar RB867515 was investigated. Senescence was characterized by strong reduction in photosynthetic pigments content, remobilization of the nutrients N, P, K, B, Cu, Fe, and Zn, and accumulation of Ca, S, Mg, B, Mn, and Al. No significant changes in the cell-wall composition occurred, and only small changes in the expression of cell wall-related genes were observed, suggesting that cell walls are preserved during senescence. Senescence-marker genes, such as SAG12-like and XET-like genes, were also identified in sugarcane and found to be highly expressed. CONCLUSIONS Our study on nutrient remobilization under senescence in a vigorous sugarcane cultivar can contribute to the understanding on how nutrient balance in a high-yielding crop is achieved. In general, neutral monosaccharide profile did not change significantly with leaf senescence, suggesting that senescing leaves of sugarcane can be as a feedstock for biofuel production using pretreatments established for non-senescing leaves without additional efforts. Based on our findings, the potential biotechnological applications for the improvement of sugarcane cultivars are discussed.
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Affiliation(s)
- Maria Thereza Bazzo Martins
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
- />Genomic Sciences and Biotechnology Program, Universidade Catolica de Brasilia, Brasília, DF 70790‑160 Brazil
| | - Wagner Rodrigo de Souza
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
| | | | - Marcos Fernando Basso
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
| | | | - Felipe Vinecky
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
| | - Polyana Kelly Martins
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
| | | | - Bruna Cersózimo Arenque-Musa
- />Laboratory of Plant Physiological Ecology (LAFIECO), Department of Botany-Institute of Biosciences, University of São Paulo, São Paulo, SP 05508-090 Brazil
| | - Amanda Pereira de Souza
- />Laboratory of Plant Physiological Ecology (LAFIECO), Department of Botany-Institute of Biosciences, University of São Paulo, São Paulo, SP 05508-090 Brazil
| | - Marcos Silveira Buckeridge
- />Laboratory of Plant Physiological Ecology (LAFIECO), Department of Botany-Institute of Biosciences, University of São Paulo, São Paulo, SP 05508-090 Brazil
| | - Adilson Kenji Kobayashi
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
| | - Betania Ferraz Quirino
- />Genetics and Biotechnology Laboratory, Embrapa Agroenergy (CNPAE), Brasília, DF 70770-901 Brazil
- />Genomic Sciences and Biotechnology Program, Universidade Catolica de Brasilia, Brasília, DF 70790‑160 Brazil
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256
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Vasheghani Farahani S, Kim YW, Schall CA. A coupled low temperature oxidative and ionic liquid pretreatment of lignocellulosic biomass. Catal Today 2016. [DOI: 10.1016/j.cattod.2015.12.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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257
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Zuorro A, Miglietta S, Familiari G, Lavecchia R. Enhanced lipid recovery from Nannochloropsis microalgae by treatment with optimized cell wall degrading enzyme mixtures. BIORESOURCE TECHNOLOGY 2016; 212:35-41. [PMID: 27078205 DOI: 10.1016/j.biortech.2016.04.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 06/05/2023]
Abstract
A statistical mixture design approach was used to investigate the effects of cell wall degrading enzymes on the recovery of lipids from Nannochloropsis sp. A preliminary screening of potentially suitable enzyme preparations, including lysozyme, cellulase and different types of hemicellulases, was carried out. The most effective preparations were then taken as basic components for the formulation of enzyme mixtures. Optimized ternary mixtures consisting of cellulase and two hemicellulases were obtained which allowed the recovery of up to 37.2g of lipids per 100g of dry biomass. SEM and TEM images of the enzymatically treated microalga revealed extensive cell damage, with degradation of the cell wall and release of intracellular material. Overall, the results obtained demonstrate that the mixture design method can be used to prepare cell wall degrading enzyme cocktails that can significantly improve the recovery of lipids or other valuable components from microalgae.
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Affiliation(s)
- Antonio Zuorro
- Department of Chemical Engineering, Materials and Environment, Sapienza University, Roma, Italy
| | - Selenia Miglietta
- Department of Anatomical, Histological, Forensic and Locomotor Apparatus Sciences, Sapienza University, Roma, Italy
| | - Giuseppe Familiari
- Department of Anatomical, Histological, Forensic and Locomotor Apparatus Sciences, Sapienza University, Roma, Italy
| | - Roberto Lavecchia
- Department of Chemical Engineering, Materials and Environment, Sapienza University, Roma, Italy.
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258
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Willson BJ, Kovács K, Wilding-Steele T, Markus R, Winzer K, Minton NP. Production of a functional cell wall-anchored minicellulosome by recombinant Clostridium acetobutylicum ATCC 824. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:109. [PMID: 27222664 PMCID: PMC4877998 DOI: 10.1186/s13068-016-0526-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/10/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND The use of fossil fuels is no longer tenable. Not only are they a finite resource, their use is damaging the environment through pollution and global warming. Alternative, environmentally friendly, renewable sources of chemicals and fuels are required. To date, the focus has been on using lignocellulose as a feedstock for microbial fermentation. However, its recalcitrance to deconstruction is making the development of economic processes extremely challenging. One solution is the generation of an organism suitable for use in consolidated bioprocessing (CBP), i.e. one able to both hydrolyse lignocellulose and ferment the released sugars, and this represents an important goal for synthetic biology. We aim to use synthetic biology to develop the solventogenic bacterium C. acetobutylicum as a CBP organism through the introduction of a cellulosome, a complex of cellulolytic enzymes bound to a scaffold protein called a scaffoldin. In previous work, we were able to demonstrate the in vivo production of a C. thermocellum-derived minicellulosome by recombinant strains of C. acetobutylicum, and aim to develop on this success, addressing potential issues with the previous strategy. RESULTS The genes for the cellulosomal enzymes Cel9G, Cel48F, and Xyn10A from C. cellulolyticum were integrated into the C. acetobutylicum genome using Allele-Coupled Exchange (ACE) technology, along with a miniscaffoldin derived from C. cellulolyticum CipC. The possibility of anchoring the recombinant cellulosome to the cell surface using the native sortase system was assessed, and the cellulolytic properties of the recombinant strains were assayed via plate growth, batch fermentation and sugar release assays. CONCLUSIONS We have been able to demonstrate the synthesis and in vivo assembly of a four-component minicellulosome by recombinant C. acetobutylicum strains. Furthermore, we have been able to anchor a minicellulosome to the C. acetobutylicum cell wall by the use of the native sortase system. The recombinant strains display an improved growth phenotype on xylan and an increase in released reducing sugar from several substrates including untreated powdered wheat straw. This constitutes an important milestone towards the development of a truly cellulolytic strain suitable for CBP.
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Affiliation(s)
- Benjamin J. Willson
- />Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Katalin Kovács
- />Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Tom Wilding-Steele
- />Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Robert Markus
- />SLIM Imaging Unit, Faculty of Medicine and Health Sciences, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Klaus Winzer
- />Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
| | - Nigel P. Minton
- />Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre, School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD UK
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259
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Costa THF, Vega-Sánchez ME, Milagres AMF, Scheller HV, Ferraz A. Tissue-specific distribution of hemicelluloses in six different sugarcane hybrids as related to cell wall recalcitrance. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:99. [PMID: 27148403 PMCID: PMC4855430 DOI: 10.1186/s13068-016-0513-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 04/20/2016] [Indexed: 05/05/2023]
Abstract
BACKGROUND Grasses are lignocellulosic materials useful to supply the billion-tons annual requirement for renewable resources that aim to produce transportation fuels and a variety of chemicals. However, the polysaccharides contained in grass cell walls are built in a recalcitrant composite. Deconstruction of these cell walls is still a challenge for the energy-efficient and economically viable transformation of lignocellulosic materials. The varied tissue-specific distribution of cell wall components adds complexity to the origins of cell wall recalcitrance in grasses. This complexity usually led to empirically developed pretreatment processes to overcome recalcitrance. A further complication is that efficient pretreatment procedures generally treat the less recalcitrant tissues more than necessary, which results in the generation of undesirable biomass degradation products. RESULTS Six different sugarcane hybrids were used as model grasses to evaluate the tissue-specific distribution of hemicelluloses and the role of these components in cell wall recalcitrance. Acetylated glucuronoarabinoxylan (GAX) occurs in all tissues. Mixed-linkage glucan (MLG) was relevant in the innermost regions of the sugarcane internodes (up to 15.4 % w/w), especially in the low-lignin content hybrids. Immunofluorescence microscopy showed that xylans predominated in vascular bundles, whereas MLG occurred mostly in the parenchyma cell walls from the pith region of the hybrids with low-lignin content. Evaluation of the digestibility of sugarcane polysaccharides by commercial enzymes indicated that the cell wall recalcitrance varied considerably along the internode regions and in the sugarcane hybrids. Pith regions of the hybrids with high MLG and low-lignin contents reached up to 85 % cellulose conversion after 72 h of hydrolysis, without any pretreatment. CONCLUSIONS The collective characteristics of the internode regions were related to the varied recalcitrance found in the samples. Components such as lignin and GAX were critical for the increased recalcitrance, but low cellulose crystallinity index, high MLG contents, and highly substituted GAX contributed to the generation of a less recalcitrant material.
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Affiliation(s)
- Thales H. F. Costa
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Miguel E. Vega-Sánchez
- />The Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 USA
- />Monsanto Company, 800N. Lindbergh Blvd., Creve Coeur (St. Louis), MO 63141 USA
| | - Adriane M. F. Milagres
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
| | - Henrik V. Scheller
- />The Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 USA
| | - André Ferraz
- />Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP 12602-810 Brazil
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260
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Akimkulova A, Zhou Y, Zhao X, Liu D. Improving the enzymatic hydrolysis of dilute acid pretreated wheat straw by metal ion blocking of non-productive cellulase adsorption on lignin. BIORESOURCE TECHNOLOGY 2016; 208:110-116. [PMID: 26930032 DOI: 10.1016/j.biortech.2016.02.059] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 05/08/2023]
Abstract
Eleven salts were selected to screen the possible metal ions for blocking the non-productive adsorption of cellulase onto the lignin of dilute acid pretreated wheat straw. Mg(2+) was screened finally as the promising candidate. The optimal concentration of MgCl2 was 1 mM, but the beneficial action was also dependent on pH, hydrolysis time and cellulase loading. Significant improvement of glucan conversion (19.3%) was observed at low cellulase loading (5 FPU/g solid). Addition of isolated lignins, tannic acid and lignin model compounds to pure cellulose hydrolysis demonstrated that phenolic hydroxyl group (Ph-OH) was the main active site blocked by Mg(2+). The interaction between Mg(2+) and Ph-OH of lignin monomeric moieties followed an order of p-hydroxyphenyl (H)>guaiacyl (G)>syringyl (S). Mg(2+) blocking made the lignin surface less negatively charged, which might weaken the hydrogen bonding and electrostatically attractive interaction between lignin and cellulase enzymes.
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Affiliation(s)
- Ardak Akimkulova
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yan Zhou
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Xuebing Zhao
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Tsinghua Innovation Center in Dongguan, Dongguan 523808, China.
| | - Dehua Liu
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Tsinghua Innovation Center in Dongguan, Dongguan 523808, China
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261
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Insights into the mechanism of enzymatic hydrolysis of xylan. Appl Microbiol Biotechnol 2016; 100:5205-14. [PMID: 27112349 DOI: 10.1007/s00253-016-7555-z] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 04/11/2016] [Accepted: 04/14/2016] [Indexed: 01/06/2023]
Abstract
Hemicelluloses are a vast group of complex, non-cellulosic heteropolysaccharides that are classified according to the principal monosaccharides present in its structure. Xylan is the most abundant hemicellulose found in lignocellulosic biomass. In the current trend of a more effective utilization of lignocellulosic biomass and developments of environmentally friendly industrial processes, increasing research activities have been directed to a practical application of the xylan component of plants and plant residues as biopolymer resources. A variety of enzymes, including main- and side-chain acting enzymes, are responsible for xylan breakdown. Xylanase is a main-chain enzyme that randomly cleaves the β-1,4 linkages between the xylopyranosyl residues in xylan backbone. This enzyme presents varying folds, mechanisms of action, substrate specificities, hydrolytic activities, and physicochemical characteristics. This review pays particular attention to different aspects of the mechanisms of action of xylan-degrading enzymes and their contribution to improve the production of bioproducts from plant biomass. Furthermore, the influence of phenolic compounds on xylanase activity is also discussed.
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262
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Siripong P, Duangporn P, Takata E, Tsutsumi Y. Phosphoric acid pretreatment of Achyranthes aspera and Sida acuta weed biomass to improve enzymatic hydrolysis. BIORESOURCE TECHNOLOGY 2016; 203:303-308. [PMID: 26744804 DOI: 10.1016/j.biortech.2015.12.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 12/12/2015] [Accepted: 12/13/2015] [Indexed: 06/05/2023]
Abstract
Achyranthes aspera and Sida acuta, two types of weed biomass are abundant and waste in Thailand. We focus on them as novel feedstock for bio-ethanol production because they contain high-cellulose content (45.9% and 46.9%, respectively) and unutilized material. Phosphoric acid (70%, 75%, and 80%) was employed for the pretreatment to improve by enzymatic hydrolysis. The pretreatment process removed most of the xylan and a part of the lignin from the weeds, while most of the glucan remained. The cellulose conversion to glucose was greater for pretreated A. aspera (86.2 ± 0.3%) than that of the pretreated S. acuta (82.2 ± 1.1%). Thus, the removal of hemicellulose significantly affected the efficiency of the enzymatic hydrolysis. The scanning electron microscopy images showed the exposed fibrous cellulose on the cell wall surface, and this substantial change of the surface structure contributed to improving the enzyme accessibility.
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Affiliation(s)
- Premjet Siripong
- Department of Biology, Faculty of Science, Naresuan University, Muang, Phitsanulok 65000, Thailand
| | - Premjet Duangporn
- Center for Agricultural Biotechnology, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Muang, Phitsanulok 65000, Thailand
| | - Eri Takata
- Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki 305-8687, Japan; Department of Agro-environmental Sciences, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Yuji Tsutsumi
- Department of Agro-environmental Sciences, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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263
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Wallace J, Brienzo M, García-Aparicio MP, Görgens JF. Lignin enrichment and enzyme deactivation as the root cause of enzymatic hydrolysis slowdown of steam pretreated sugarcane bagasse. N Biotechnol 2016; 33:361-71. [PMID: 26820122 DOI: 10.1016/j.nbt.2016.01.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 11/25/2015] [Accepted: 01/14/2016] [Indexed: 01/21/2023]
Abstract
The enzymatic hydrolysis (EH) rate normally decreases during the hydrolysis, leaving unhydrolyzed material as residue. This phenomenon occurs during the hydrolysis of both cellulose (avicel) and lignocellulosic material, in nature or even pretreated. The progression of EH of steam pretreated sugarcane bagasse was associated with an initial (fast), intermediate (slower) and recalcitrant (slowest) phases, at glucan to glucose conversion yields of 61.7, 81.6 and 86%, respectively. Even though the EH of avicel as a simpler material than steam pretreated sugarcane bagasse, EH slowdown was present. The less thermo-stable endo-xylanase lost 58% of initial enzyme activity, followed by β-glucosidase that lost 16%, culminating in FPase activity loss of 30% in the first 24hours. After 72hours of EH the total loss of FPase activity was 40% compared to the initial activity. Analysis of the solid residue from EH showed that lignin content, phenolic compounds and ash increased while glucan decreased as hydrolysis progressed. During the initial fast phase of EH, the total solid residue surface area consisted predominantly of internal surface area. Thereafter, in the intermediate and recalcitrant phases of EH, the ratio of external:internal surface area increased. The proposed fiber damage and decrease in internal surface area, probably by EH action, was visualized by scanning electron microscopy imagery. The higher lignin/glucan ratio as EH progressed and enzyme deactivation by thermo instability were the main effects observed, respectively to substrate and enzyme.
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Affiliation(s)
- Joshua Wallace
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa
| | - Michel Brienzo
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
| | - María P García-Aparicio
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa; Department of Microbiology, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa
| | - Johann F Görgens
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa
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264
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Jiang J, Wang J, Zhang X, Wolcott M. Evaluation of physical structural features on influencing enzymatic hydrolysis efficiency of micronized wood. RSC Adv 2016. [DOI: 10.1039/c6ra22371k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enzymatic hydrolysis of lignocellulosic biomass is highly dependent on the changes in structural features after pretreatment.
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Affiliation(s)
- Jinxue Jiang
- Composite Materials and Engineering Center
- Washington State University
- Pullman
- USA
| | - Jinwu Wang
- Forest Products Laboratory
- United States Department of Agriculture Forest Service
- Orono
- USA
| | - Xiao Zhang
- Voiland School of Chemical Engineering and Bioengineering
- Washington State University
- Richland
- USA
| | - Michael Wolcott
- Composite Materials and Engineering Center
- Washington State University
- Pullman
- USA
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265
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Lu X, Zheng X, Li X, Zhao J. Adsorption and mechanism of cellulase enzymes onto lignin isolated from corn stover pretreated with liquid hot water. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:118. [PMID: 27274766 PMCID: PMC4891831 DOI: 10.1186/s13068-016-0531-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/19/2016] [Indexed: 05/02/2023]
Abstract
BACKGROUND In the bioconversion of lignocellulosic substrates, the adsorption behavior of cellulase onto lignin has a negative effect on enzymatic hydrolysis of cellulose, decreasing glucose production during enzymatic hydrolysis, thus decreasing the yield of fermentation and the production of useful products. Understanding the interaction between lignin and cellulase is necessary to optimize the components of cellulase mixture, genetically engineer high-efficiency cellulase, and reduce cost of bioconversion. Most lignin is not removed during liquid hot water (LHW) pretreatment, and the characteristics of lignin in solid substrate are also changed. To understand the interactions between cellulase and lignin, this study investigated the change in the characteristics of lignin obtained from corn stover, as well as the behavior of cellulase adsorption onto lignin, under various severities of LHW pretreatment. RESULTS LHW pretreatment removed most hemicellulose and some lignin in corn stover, as well as improved enzymatic digestibility of corn stover. After LHW pretreatment, the molecular weight of lignin obviously increased, whereas its polydispersity decreased and became more negative. The hydrophobicity and functional groups in lignin also changed. Adsorption of cellulase from Penicillium oxalicum onto lignin isolated from corn stover was enhanced after LHW pretreatment, and increased under increasing pretreatment severity. Different adsorption behaviors were observed in different lignin samples and components of cellulase mixtures, even in different cellobiohydrolases (CBHs), endo-beta-1, 4-glucanases (EGs). The greatest reduction in enzyme activity caused by lignin was observed in CBH, followed by that in xylanase and then in EG and β-Glucosidase (BGL). The adsorption behavior exerted different effects on subsequent enzymatic hydrolysis of various biomass substrates. Hydrophobic and electrostatic interactions may be important factors affecting different adsorption behaviors between lignin and cellulase. CONCLUSIONS LHW pretreatment changed the characteristics of the remaining lignin in corn stover, thus affected the adsorption behavior of lignin toward cellulase. For different protein components in cellulase solution from P. oxalicum, electrostatic action was a main factor influencing the adsorption of EG and xylanase onto lignin in corn stover, while hydrophobicity affected the adsorption of CBH and BGL onto lignin.
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Affiliation(s)
- Xianqin Lu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 Shandong China
| | - Xiaoju Zheng
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 Shandong China
| | - Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 Shandong China
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100 Shandong China
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266
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Nkemka VN, Li Y, Hao X. Effect of thermal and alkaline pretreatment of giant miscanthus and Chinese fountaingrass on biogas production. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2016; 73:849-856. [PMID: 26901728 DOI: 10.2166/wst.2015.559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Giant miscanthus (Miscanthus × giganteus) and Chinese fountaingrass (Pennisetum alopecuroides (L.) Spreng), cultivated for landscaping and soil conservation, are potential energy crops. The study investigated the effect of combined thermal and alkaline pretreatments on biogas production of these energy crops. The pretreatment included two types of alkali (6% CaO and 6% NaOH) at 22, 70 and 100 °C. The alkaline pretreatment resulted in a greater breakdown of the hemicellulose fraction, with CaO more effective than NaOH. Pretreatment of giant miscanthus with 6% CaO at 100 °C for 24 h produced a CH4 yield (313 mL g(-1) volatile solids (VS)) that was 1.7 times that of the untreated sample (186 mL g(-1) VS). However, pretreatment of Chinese fountaingrass with 6% CaO or 6% NaOH at 70 °C for 24 h resulted in similar CH4 yields (328 and 302 mL g(-1) VS for CaO and NaOH pretreatments) as the untreated sample (311 mL g(-1) VS). Chinese fountaingrass was more easily digestible but had a low overall CH4 yield per hectare (1,831 m(3) ha(-1) y(-1)) compared to giant miscanthus (6,868 m(3) ha(-1) y(-1)). This study demonstrates the potential of thermal/alkaline pretreatment and the use of giant miscanthus and Chinese fountaingrass for biogas production.
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Affiliation(s)
- Valentine Nkongndem Nkemka
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Ave S. Lethbridge, Alberta, T1J 4B1, Canada E-mail:
| | - Yongqiang Li
- Department of Grassland Science, College of Resource and Environment, Shandong Agricultural University, Taian, Shandong, 271018 China
| | - Xiying Hao
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Ave S. Lethbridge, Alberta, T1J 4B1, Canada E-mail:
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267
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Mathew AK, Parameshwaran B, Sukumaran RK, Pandey A. An evaluation of dilute acid and ammonia fiber explosion pretreatment for cellulosic ethanol production. BIORESOURCE TECHNOLOGY 2016; 199:13-20. [PMID: 26358144 DOI: 10.1016/j.biortech.2015.08.121] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/24/2015] [Accepted: 08/27/2015] [Indexed: 06/05/2023]
Abstract
The challenge associated with cellulosic ethanol production is maximizing sugar yield at low cost. Current research is being focused to develop a pretreatment method to overcome biomass recalcitrance in an efficient way. This review is focused on two major pretreatments: dilute acid (DA) and ammonia fiber explosion (AFEX) pretreatment of corn stover and how these pretreatment cause morphological and chemical changes to corn stover in order to overcome the biomass recalcitrance. This review highlights the key differences of these two pretreatments based on compositional analysis, cellulose and its crystallinity, morphological changes, structural changes to lignin, enzymatic reactivity and enzyme adsorption onto pretreated solids and finally cellulosic ethanol production from the hydrolysate of DA and AFEX treated corn stover. Each stage of the process, AFEX pretreated corn stover was superior to DA treated corn stover.
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Affiliation(s)
- Anil Kuruvilla Mathew
- Centre for Biofuels, Biotechnology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019, India
| | - Binod Parameshwaran
- Centre for Biofuels, Biotechnology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019, India
| | - Rajeev Kumar Sukumaran
- Centre for Biofuels, Biotechnology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019, India
| | - Ashok Pandey
- Centre for Biofuels, Biotechnology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695019, India
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268
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Lou H, Yuan L, Qiu X, Qiu K, Fu J, Pang Y, Huang J. Enhancing enzymatic hydrolysis of xylan by adding sodium lignosulfonate and long-chain fatty alcohols. BIORESOURCE TECHNOLOGY 2016; 200:48-54. [PMID: 26476164 DOI: 10.1016/j.biortech.2015.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/04/2015] [Accepted: 10/06/2015] [Indexed: 06/05/2023]
Abstract
Sodium lignosulfonate (SXSL) and long-chain fatty alcohols (LFAs) could enhance the enzymatic hydrolysis of xylan, and the compound of SXSL and LFAs have synergies on the enzymatic hydrolysis. SXSL shows a strong enhancement in buffer pH range from 4.0 to 6.0. The enhancement increased with the SXSL dosage and the xylanase loading. The cellulose and lignin in corncob substrate could not only adsorb xylanase nonproductively, but also seriously reduce the accessibility of xylanase on xylan to impede the enzymatic hydrolysis of xylan. Cellulase could break the plant cell wall structure of corncob and make additives work better. The xylose yield of corncob at 72h increased from 59.4% to 73.7% by adding the compound of 5g/L SXSL and 0.01% (v/v) n-decanol, which was higher than that without cellulase and additives by 30.7%. Meanwhile, the glucose yield at 72h of corncob increased from 45.8% to 62.3%.
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Affiliation(s)
- Hongming Lou
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China
| | - Long Yuan
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Xueqing Qiu
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China.
| | - Kexian Qiu
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Jinguo Fu
- Guangdong Key Laboratory of Sugarcane Improvement & Biorefinery, Sugarcane Industry Research Institute, Guangzhou, China
| | - Yuxia Pang
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Jinhao Huang
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
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269
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Monschein M, Nidetzky B. Effect of pretreatment severity in continuous steam explosion on enzymatic conversion of wheat straw: Evidence from kinetic analysis of hydrolysis time courses. BIORESOURCE TECHNOLOGY 2016; 200:287-96. [PMID: 26496218 DOI: 10.1016/j.biortech.2015.10.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/08/2015] [Accepted: 10/10/2015] [Indexed: 05/15/2023]
Abstract
Focusing on continuous steam explosion, the influence of pretreatment severity due to varied acid loading on hydrolysis of wheat straw by Trichoderma reesei cellulases was investigated based on kinetic evaluation of the saccharification of each pretreated substrate. Using semi-empirical descriptors of the hydrolysis time course, key characteristics of saccharification efficiency were captured in a quantifiable fashion. Not only hydrolysis rates per se, but also the transition point of their bi-phasic decline was crucial for high saccharification degree. After 48h the highest saccharification was achieved for substrate pretreated at relatively low severity (1.2% acid). Higher severity increased enzyme binding to wheat straw, but reduced the specific hydrolysis rates. Higher affinity of the lignocellulosic material for cellulases does not necessarily result in increased saccharification, probably because of lignin modifications occurring at high pretreatment severities. At comparable severity, continuous pretreatment produced a substrate more susceptible to enzymatic hydrolysis than the batch process.
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Affiliation(s)
- Mareike Monschein
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH, Petersgasse 14, 8010 Graz, Austria
| | - Bernd Nidetzky
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH, Petersgasse 14, 8010 Graz, Austria; Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/I, 8010 Graz, Austria.
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270
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Shuai L, Luterbacher J. Organic Solvent Effects in Biomass Conversion Reactions. CHEMSUSCHEM 2016; 9:133-155. [PMID: 26676907 DOI: 10.1002/cssc.201501148] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/03/2015] [Indexed: 06/05/2023]
Abstract
Transforming lignocellulosic biomass into fuels and chemicals has been intensely studied in recent years. A large amount of work has been dedicated to finding suitable solvent systems, which can improve the transformation of biomass into value-added chemicals. These efforts have been undertaken based on numerous research results that have shown that organic solvents can improve both conversion and selectivity of biomass to platform molecules. We present an overview of these organic solvent effects, which are harnessed in biomass conversion processes, including conversion of biomass to sugars, conversion of sugars to furanic compounds, and production of lignin monomers. A special emphasis is placed on comparing the solvent effects on conversion and product selectivity in water with those in organic solvents while discussing the origins of the differences that arise. We have categorized results as benefiting from two major types of effects: solvent effects on solubility of biomass components including cellulose and lignin and solvent effects on chemical thermodynamics including those affecting reactants, intermediates, products, and/or catalysts. Finally, the challenges of using organic solvents in industrial processes are discussed from the perspective of solvent cost, solvent stability, and solvent safety. We suggest that a holistic view of solvent effects, the mechanistic elucidation of these effects, and the careful consideration of the challenges associated with solvent use could assist researchers in choosing and designing improved solvent systems for targeted biomass conversion processes.
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Affiliation(s)
- Li Shuai
- Laboratory of Sustainable and Catalytic Processing, Institute of Chemical Sciences and Engineering, École polytechnique fédérale de Lausanne (EPFL), Station 6, CH.H2.545, 1015, Lausanne, Switzerland
| | - Jeremy Luterbacher
- Laboratory of Sustainable and Catalytic Processing, Institute of Chemical Sciences and Engineering, École polytechnique fédérale de Lausanne (EPFL), Station 6, CH.H2.545, 1015, Lausanne, Switzerland.
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271
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Kumar A, Gautam A, Dutt D. Biotechnological Transformation of Lignocellulosic Biomass in to Industrial Products: An Overview. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/abb.2016.73014] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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272
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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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273
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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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274
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Bhalla A, Bansal N, Stoklosa RJ, Fountain M, Ralph J, Hodge DB, Hegg EL. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:34. [PMID: 26862348 PMCID: PMC4746924 DOI: 10.1186/s13068-016-0442-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 01/20/2016] [Indexed: 05/11/2023]
Abstract
BACKGROUND Strategies to improve copper-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment of hybrid poplar were investigated. These improvements included a combination of increasing hydrolysis yields, while simultaneously decreasing process inputs through (i) more efficient utilization of H2O2 and (ii) the addition of an alkaline extraction step prior to the metal-catalyzed AHP pretreatment. We hypothesized that utilizing this improved process could substantially lower the chemical inputs needed during pretreatment. RESULTS Hybrid poplar was pretreated utilizing a modified process in which an alkaline extraction step was incorporated prior to the Cu-AHP treatment step and H2O2 was added batch-wise over the course of 10 h. Our results revealed that the alkaline pre-extraction step improved both lignin and xylan solubilization, which ultimately led to improved glucose (86 %) and xylose (95 %) yields following enzymatic hydrolysis. An increase in the lignin solubilization was also observed with fed-batch H2O2 addition relative to batch-only addition, which again resulted in increased glucose and xylose yields (77 and 93 % versus 63 and 74 %, respectively). Importantly, combining these strategies led to significantly improved sugar yields (96 % glucose and 94 % xylose) following enzymatic hydrolysis. In addition, we found that we could substantially lower the chemical inputs (enzyme, H2O2, and catalyst), while still maintaining high product yields utilizing the improved Cu-AHP process. This pretreatment also provided a relatively pure lignin stream consisting of ≥90 % Klason lignin and only 3 % xylan and 2 % ash following precipitation. Two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR and size-exclusion chromatography demonstrated that the solubilized lignin was high molecular weight (Mw ≈ 22,000 Da) and only slightly oxidized relative to lignin from untreated poplar. CONCLUSIONS This study demonstrated that the fed-batch, two-stage Cu-AHP pretreatment process was effective in pretreating hybrid poplar for its conversion into fermentable sugars. Results showed sugar yields near the theoretical maximum were achieved from enzymatically hydrolyzed hybrid poplar by incorporating an alkaline extraction step prior to pretreatment and by efficiently utilizing H2O2 during the Cu-AHP process. Significantly, this study reports high sugar yields from woody biomass treated with an AHP pretreatment under mild reaction conditions.
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Affiliation(s)
- Aditya Bhalla
- />DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- />Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - Namita Bansal
- />DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- />Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - Ryan J. Stoklosa
- />DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- />Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, USA
| | - Mackenzie Fountain
- />Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
| | - John Ralph
- />DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, USA
| | - David B. Hodge
- />DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- />Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, USA
- />Division of Sustainable Process Engineering, Luleå University of Technology, Luleå, Sweden
| | - Eric L. Hegg
- />DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, USA
- />Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, USA
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275
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A Neurospora crassa ÿ-glucosidase with potential for lignocellulose hydrolysis shows strong glucose tolerance and stimulation by glucose and xylose. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcatb.2015.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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276
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Overcome the recalcitrance of eucalyptus bark to enzymatic hydrolysis by concerted ionic liquid pretreatment. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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277
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Bradfield MFA, Nicol W. Continuous succinic acid production from xylose by Actinobacillus succinogenes. Bioprocess Biosyst Eng 2015; 39:233-44. [PMID: 26610345 DOI: 10.1007/s00449-015-1507-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/14/2015] [Indexed: 11/28/2022]
Abstract
Continuous, anaerobic fermentations of D-xylose were performed by Actinobacillus succinogenes 130Z in a custom, biofilm reactor at dilution rates of 0.05, 0.10 and 0.30 h(-1). Succinic acid yields on xylose (0.55-0.68 g g(-1)), titres (10.9-29.4 g L(-1)) and productivities (1.5-3.4 g L(-1) h(-1)) were lower than those of a previous study on glucose, but product ratios (succinic acid/acetic acid = 3.0-5.0 g g(-1)) and carbohydrate consumption rates were similar. Also, mass balance closures on xylose were up to 18.2 % lower than those on glucose. A modified HPLC method revealed pyruvic acid excretion at appreciable concentrations (1.2-1.9 g L(-1)) which improved the mass balance closure by up to 16.8 %. Furthermore, redox balances based on the accounted xylose consumed and the excreted metabolites, indicated an overproduction of reducing power. The oxidative pentose phosphate pathway was shown to be a plausible source of the additional reducing power.
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Affiliation(s)
- Michael F A Bradfield
- Department of Chemical Engineering, University of Pretoria, Lynnwood Road, Hatfield, Pretoria, 0002, South Africa.
| | - Willie Nicol
- Department of Chemical Engineering, University of Pretoria, Lynnwood Road, Hatfield, Pretoria, 0002, South Africa.
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278
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Gu Y, Zhang Y, Zhou X. Effect of Ca(OH)2 pretreatment on extruded rice straw anaerobic digestion. BIORESOURCE TECHNOLOGY 2015; 196:116-122. [PMID: 26231131 DOI: 10.1016/j.biortech.2015.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 06/30/2015] [Accepted: 07/01/2015] [Indexed: 06/04/2023]
Abstract
It has been proven that extrusion can change the structure of rice straw and increase biogas production, but the effect of a single pretreatment is limited. Ca(OH)2 pretreatment was used to enhance the enzyme hydrolysis and biogas production of extruded rice straw. After Ca(OH)2 pretreatment, the glucose and xylose conversion rates in enzymatic hydrolysis increased from 36.0% and 22.4% to 66.8% and 50.2%, respectively. The highest biogas production observed in 8% and 10% Ca(OH)2 pretreated rice straw reached 564.7mL/g VS and 574.5mL/g VS, respectively, which are 34.3% and 36.7% higher than the non-Ca(OH)2-loaded sample. The Ca(OH)2 pretreatment can effectively remove the lignin and increase the fermentable sugar content. The structural changes in the extruded rice straw have also been analyzed by XRD, FTIR, and SEM. Considering all of the results, an 8% Ca(OH)2 loading rate is the best option for the pretreatment of extruded rice straw.
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Affiliation(s)
- Yu Gu
- Key Laboratory of Yangtze Water Environment of Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yalei Zhang
- Key Laboratory of Yangtze Water Environment of Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xuefei Zhou
- Key Laboratory of Yangtze Water Environment of Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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279
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Shi N, Liu QY, Wang TJ, Zhang Q, Ma LL, Cai CL. Production of 5-Hydroxymethylfurfural and Furfural from Lignocellulosic Biomass in Water-Tetrahydrofuran Media with Sodium Bisulfate. CHINESE J CHEM PHYS 2015. [DOI: 10.1063/1674-0068/28/cjcp1501008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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280
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He Q, Chen HZ. Comparative study on occurrence characteristics of matrix water in static and gas double-dynamic solid-state fermentations using low-field NMR and MRI. Anal Bioanal Chem 2015; 407:9115-23. [DOI: 10.1007/s00216-015-9077-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/20/2015] [Accepted: 09/23/2015] [Indexed: 10/22/2022]
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281
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Zhou L, Li Z, Pang J, Zheng M, Wang A, Zhang T. Catalytic conversion of Jerusalem artichoke tuber into hexitols using the bifunctional catalyst Ru/(AC-SO3H). CHINESE JOURNAL OF CATALYSIS 2015. [DOI: 10.1016/s1872-2067(15)60933-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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282
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Paës G, von Schantz L, Ohlin M. Bioinspired assemblies of plant cell wall polymers unravel the affinity properties of carbohydrate-binding modules. SOFT MATTER 2015; 11:6586-94. [PMID: 26189625 DOI: 10.1039/c5sm01157d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Lignocellulose-acting enzymes play a central role in the biorefinery of plant biomass to make fuels, chemicals and materials. These enzymes are often appended to carbohydrate binding modules (CBMs) that promote substrate targeting. When used in plant materials, which are complex assemblies of polymers, the binding properties of CBMs can be difficult to understand and predict, thus limiting the efficiency of enzymes. In order to gain more information on the binding properties of CBMs, some bioinspired model assemblies that contain some of the polymers and covalent interactions found in the plant cell walls have been designed. The mobility of three engineered CBMs has been investigated by FRAP in these assemblies, while varying the parameters related to the polymer concentration, the physical state of assemblies and the oligomerization state of CBMs. The features controlling the mobility of the CBMs in the assemblies have been quantified and hierarchized. We demonstrate that the parameters can have additional or opposite effects on mobility, depending on the CBM tested. We also find evidence of a relationship between the mobility of CBMs and their binding strength. Overall, bioinspired assemblies are able to reveal the unique features of affinity of CBMs. In particular, the results show that oligomerization of CBMs and the presence of ferulic acid motifs in the assemblies play an important role in the binding affinity of CBMs. Thus we propose that these features should be finely tuned when CBMs are used in plant cell walls to optimise bioprocesses.
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Affiliation(s)
- Gabriel Paës
- INRA, UMR0614 Fractionnement des AgroRessources et Environnement, 2 esplanade Roland-Garros, 51100 Reims, France.
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283
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Gandolfi S, Pistone L, Ottolina G, Xu P, Riva S. Hemp hurds biorefining: A path to green L-(+)-lactic acid production. BIORESOURCE TECHNOLOGY 2015; 191:59-65. [PMID: 25983223 DOI: 10.1016/j.biortech.2015.04.118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 06/04/2023]
Abstract
Sugars streams generated by organosolv pretreatment of hemp hurds, cellulose (C6) and hemicellulose (C5) fractions, were fermented to lactic acid (LA) by Bacillus coagulans strains XZL4 and DSM1. Pretreatment conditions and enzymatic hydrolysis were optimized and B. coagulans aptness to use lignocellulosic-derived sugars as a carbon source was evaluated. Methanolic organosolv pretreatment with 2.5% (w/w) H2SO4 gave the best results in terms of glucan recovery (98%), enzymatic hydrolysis of pretreated biomass (70%) and hemicellulosic sugars recovery (61%). C6 and C5 sugars fermentation by strain XZL4 gave, high LA yields (0.90 and 0.84 g/g), high titers (141 and 109 g/L), and high enantiomeric excess (>99%). Overall, 42 g of l-LA were obtained from 100 g of raw hemp hurds. These results can be considered promising for lignocellulosic feedstock valorization toward the production of polymer-grade LA.
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Affiliation(s)
- Stefano Gandolfi
- Istituto di Chimica del Riconoscimento Molecolare (ICRM), Consiglio Nazioneale delle Ricerche (CNR), Via Mario Bianco 9, 20131 Milano, Italy; The Protein Factory, Centro Interuniversitario di Biotecnologie Proteiche, Università degli Studi dell'Insubria, Politecnico di Milano, ICRM CNR, Milano, Italy.
| | - Lucia Pistone
- Istituto di Chimica del Riconoscimento Molecolare (ICRM), Consiglio Nazioneale delle Ricerche (CNR), Via Mario Bianco 9, 20131 Milano, Italy; The Protein Factory, Centro Interuniversitario di Biotecnologie Proteiche, Università degli Studi dell'Insubria, Politecnico di Milano, ICRM CNR, Milano, Italy
| | - Gianluca Ottolina
- Istituto di Chimica del Riconoscimento Molecolare (ICRM), Consiglio Nazioneale delle Ricerche (CNR), Via Mario Bianco 9, 20131 Milano, Italy; The Protein Factory, Centro Interuniversitario di Biotecnologie Proteiche, Università degli Studi dell'Insubria, Politecnico di Milano, ICRM CNR, Milano, Italy
| | - Ping Xu
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Sergio Riva
- Istituto di Chimica del Riconoscimento Molecolare (ICRM), Consiglio Nazioneale delle Ricerche (CNR), Via Mario Bianco 9, 20131 Milano, Italy; The Protein Factory, Centro Interuniversitario di Biotecnologie Proteiche, Università degli Studi dell'Insubria, Politecnico di Milano, ICRM CNR, Milano, Italy
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284
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Comparative Secretome Analysis of Aspergillus niger, Trichoderma reesei, and Penicillium oxalicum During Solid-State Fermentation. Appl Biochem Biotechnol 2015; 177:1252-71. [DOI: 10.1007/s12010-015-1811-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/17/2015] [Indexed: 10/23/2022]
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285
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Vicentini R, Bottcher A, Brito MDS, dos Santos AB, Creste S, Landell MGDA, Cesarino I, Mazzafera P. Large-Scale Transcriptome Analysis of Two Sugarcane Genotypes Contrasting for Lignin Content. PLoS One 2015; 10:e0134909. [PMID: 26241317 PMCID: PMC4524650 DOI: 10.1371/journal.pone.0134909] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/15/2015] [Indexed: 12/16/2022] Open
Abstract
Sugarcane is an important crop worldwide for sugar and first generation ethanol production. Recently, the residue of sugarcane mills, named bagasse, has been considered a promising lignocellulosic biomass to produce the second-generation ethanol. Lignin is a major factor limiting the use of bagasse and other plant lignocellulosic materials to produce second-generation ethanol. Lignin biosynthesis pathway is a complex network and changes in the expression of genes of this pathway have in general led to diverse and undesirable impacts on plant structure and physiology. Despite its economic importance, sugarcane genome was still not sequenced. In this study a high-throughput transcriptome evaluation of two sugarcane genotypes contrasting for lignin content was carried out. We generated a set of 85,151 transcripts of sugarcane using RNA-seq and de novo assembling. More than 2,000 transcripts showed differential expression between the genotypes, including several genes involved in the lignin biosynthetic pathway. This information can give valuable knowledge on the lignin biosynthesis and its interactions with other metabolic pathways in the complex sugarcane genome.
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Affiliation(s)
- Renato Vicentini
- Systems Biology Laboratory, Centre for Molecular Biology and Genetic Engineering, State University of Campinas, Campinas, SP, Brazil
- * E-mail:
| | - Alexandra Bottcher
- Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
| | - Michael dos Santos Brito
- Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
- Sugarcane Center, Agronomic Institute of Campinas, Ribeirão Preto, SP, Brazil
| | | | - Silvana Creste
- Sugarcane Center, Agronomic Institute of Campinas, Ribeirão Preto, SP, Brazil
| | | | - Igor Cesarino
- Department of Botany, Institute of Biosciences, University of São Paulo, São Paulo, SP, Brazil
| | - Paulo Mazzafera
- Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, SP, Brazil
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286
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Westman JO, Franzén CJ. Current progress in high cell density yeast bioprocesses for bioethanol production. Biotechnol J 2015. [PMID: 26211654 DOI: 10.1002/biot.201400581] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
High capital costs and low reaction rates are major challenges for establishment of fermentation-based production systems in the bioeconomy. Using high cell density cultures is an efficient way to increase the volumetric productivity of fermentation processes, thereby enabling faster and more robust processes and use of smaller reactors. In this review, we summarize recent progress in the application of high cell density yeast bioprocesses for first and second generation bioethanol production. High biomass concentrations obtained by retention of yeast cells in the reactor enables easier cell reuse, simplified product recovery and higher dilution rates in continuous processes. High local cell density cultures, in the form of encapsulated or strongly flocculating yeast, furthermore obtain increased tolerance to convertible fermentation inhibitors and utilize glucose and other sugars simultaneously, thereby overcoming two additional hurdles for second generation bioethanol production. These effects are caused by local concentration gradients due to diffusion limitations and conversion of inhibitors and sugars by the cells, which lead to low local concentrations of inhibitors and glucose. Quorum sensing may also contribute to the increased stress tolerance. Recent developments indicate that high cell density methodology, with emphasis on high local cell density, offers significant advantages for sustainable second generation bioethanol production.
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Affiliation(s)
- Johan O Westman
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden
| | - Carl Johan Franzén
- Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden.
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287
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Bundhoo MAZ, Mohee R, Hassan MA. Effects of pre-treatment technologies on dark fermentative biohydrogen production: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2015; 157:20-48. [PMID: 25881150 DOI: 10.1016/j.jenvman.2015.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 04/05/2015] [Accepted: 04/07/2015] [Indexed: 05/24/2023]
Abstract
Biohydrogen production from dark fermentation of lignocellulosic materials represents a huge potential in terms of renewable energy exploitation. However, the low hydrogen yield is currently hindering its development on industrial scale. This study reviewed various technologies that have been investigated for enhancing dark fermentative biohydrogen production. The pre-treatment technologies can be classified based on their applications as inoculum or substrates pre-treatment or they can be categorised into physical, chemical, physicochemical and biological based on the techniques used. From the different technologies reviewed, heat and acid pre-treatments are the most commonly studied technologies for both substrates and inoculum pre-treatment. Nevertheless, these two technologies need not necessarily be the most suitable since across different studies, a wide array of other emerging techniques as well as combined technologies have yielded positive findings. To date, there exists no perfect technology for either inoculum or substrate pre-treatment. Although the aim of inoculum pre-treatment is to suppress H2-consumers and enrich H2-producers, many sporulating H2-consumers survive the pre-treatment while some non-spore H2-producers are inhibited. Besides, several inoculum pre-treatment techniques are not effective in the long run and repeated pre-treatment may be required for continuous suppression of H2-consumers and sustained biohydrogen production. Furthermore, many technologies employed for substrates pre-treatment may yield inhibitory compounds that can eventually decrease biohydrogen production. Consequently, much research needs to be done to find out the best technology for both substrates and inoculum pre-treatment while also taking into consideration the energetic, economic and technical feasibility of implementing such a process on an industrial scale.
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Affiliation(s)
- M A Zumar Bundhoo
- Department of Chemical & Environmental Engineering, Faculty of Engineering, University of Mauritius, Réduit, Mauritius.
| | | | - M Ali Hassan
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia.
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288
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Pattathil S, Hahn MG, Dale BE, Chundawat SPS. Insights into plant cell wall structure, architecture, and integrity using glycome profiling of native and AFEXTM-pre-treated biomass. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4279-94. [PMID: 25911738 PMCID: PMC4493783 DOI: 10.1093/jxb/erv107] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Cell walls, which constitute the bulk of plant biomass, vary considerably in their structure, composition, and architecture. Studies on plant cell walls can be conducted on both native and pre-treated plant biomass samples, allowing an enhanced understanding of these structural and compositional variations. Here glycome profiling was employed to determine the relative abundance of matrix polysaccharides in several phylogenetically distinct native and pre-treated plant biomasses. Eight distinct biomass types belonging to four different subgroups (i.e. monocot grasses, woody dicots, herbaceous dicots, and softwoods) were subjected to various regimes of AFEX™ (ammonia fiber expansion) pre-treatment [AFEX is a trademark of MBI, Lansing (http://www.mbi.org]. This approach allowed detailed analysis of close to 200 cell wall glycan epitopes and their relative extractability using a high-throughput platform. In general, irrespective of the phylogenetic origin, AFEX™ pre-treatment appeared to cause loosening and improved accessibility of various xylan epitope subclasses in most plant biomass materials studied. For most biomass types analysed, such loosening was also evident for other major non-cellulosic components including subclasses of pectin and xyloglucan epitopes. The studies also demonstrate that AFEX™ pre-treatment significantly reduced cell wall recalcitrance among diverse phylogenies (except softwoods) by inducing structural modifications to polysaccharides that were not detectable by conventional gross composition analyses. It was found that monitoring changes in cell wall glycan compositions and their relative extractability for untreated and pre-treated plant biomass can provide an improved understanding of variations in structure and composition of plant cell walls and delineate the role(s) of matrix polysaccharides in cell wall recalcitrance.
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Affiliation(s)
- Sivakumar Pattathil
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Michael G Hahn
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Bruce E Dale
- DOE Great Lakes Bioenergy Research Center, Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA
| | - Shishir P S Chundawat
- DOE Great Lakes Bioenergy Research Center, Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA Present address: Department of Chemical and Biochemical Engineering, C-150A Engineering Building, Rutgers The State University of New Jersey, Piscataway, NJ 08854, USA
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289
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Ma J, Ji Z, Chen JC, Zhou X, Kim YS, Xu F. The mechanism of xylans removal during hydrothermal pretreatment of poplar fibers investigated by immunogold labeling. PLANTA 2015; 242:327-337. [PMID: 25926363 DOI: 10.1007/s00425-015-2313-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 04/21/2015] [Indexed: 06/04/2023]
Abstract
Hydrothermal pretreatment initially removed the lignin-free xylan from the middle layer of secondary wall, followed by the lignin-bound xylan, but the cellulose-bound xylan was seldom removed by this pretreatment. An in-depth understanding of the mechanism of xylan removal during hydrothermal pretreatment (HTP) of wood is critical for cost-effective conversion of lignocellulosic biomass to biofuels. Several studies demonstrated the kinetics and mechanism of xylan removal during HTP on molecular scale, but the dissolution mechanism of xylan during HTP remains unclear at ultra-structural level. Our study investigated changes in the micro-distribution of xylan in poplar fiber cell walls during HTP by transmission electron microscopy (TEM) in combination with immunogold labeling. The study revealed that HTP caused greater decline in the density of xylan labeling in the S2 layer of fiber wall than in the S1 layer. There was a greater loss in the density of xylan labeling during HTP in the delignified and enzymatically treated fibers compared to untreated fibers. We propose that in the initial stages of HTP lignin-free xylan in the S2 layer was more readily hydrolyzed than in the S1 layer by hydronium ions. With increasing pretreatment time, the xylan covalently bound to lignin was also removed from the S2 layer due to the dissolution of lignin. The xylan tightly bound to cellulose was seldom removed during HTP, but was hydrolyzed in subsequent enzymatic treatment. This TEM-immunolabeling investigation reveals the manner in which different xylan fractions are removed from fiber cell wall during HTP, and we expect the information to be helpful in developing processes tailored for more effective conversion of cellulosic biomass into fermentable sugars.
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Affiliation(s)
- Jing Ma
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083, China
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290
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Eom IY, Oh YH, Park SJ, Lee SH, Yu JH. Fermentative l-lactic acid production from pretreated whole slurry of oil palm trunk treated by hydrothermolysis and subsequent enzymatic hydrolysis. BIORESOURCE TECHNOLOGY 2015; 185:143-149. [PMID: 25768416 DOI: 10.1016/j.biortech.2015.02.060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/12/2015] [Accepted: 02/13/2015] [Indexed: 06/04/2023]
Abstract
A simple and cost-effective biochemical conversion process consisting of hydrothermal treatment, enzymatic hydrolysis and fermentation of pretreated whole slurry (PWS) was developed for producing l-lactic acid (L-LA) from oil palm trunk (OPT). When OPT was hydrothermally treated at optimal condition capable of achieving maximum yield of hemicellulosic sugars after enzymatic hydrolysis, the enzymatic digestibility of the PWS afforded a yield of 81.4% of the theoretical glucose yield (TGY). However, glucose yield from washed pretreated solid (WPS) was only 43.5% of TGY. The use of two hydrolysates from PWS and WPS for fermentation by Lactobacillus paracasei engineered to selectively produce L-LA afforded yields of 89.5% and 45.8% of the theoretical LA yield (TLY), respectively. This study confirmed the inevitable extensive sugar loss during washing of pretreated slurry due to loss of soluble starch. Alternatively, the proposed design process is considered suitable for converting OPT to L-LA without such starch loss.
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Affiliation(s)
- In-Yong Eom
- Center for Bio-based Chemistry, Green Chemistry & Engineering Division, Korea Research Institute of Chemical Technology, P.O. Box 107, 141 Gajeong-ro, Yuseong-gu, Daejeon 305-600, Republic of Korea
| | - Young-Hoon Oh
- Center for Bio-based Chemistry, Green Chemistry & Engineering Division, Korea Research Institute of Chemical Technology, P.O. Box 107, 141 Gajeong-ro, Yuseong-gu, Daejeon 305-600, Republic of Korea
| | - Si Jae Park
- Department of Environmental Engineering and Energy, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggido 449-728, Republic of Korea
| | - Seung-Hwan Lee
- Department of Biotechnology and Bioengineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, Republic of Korea
| | - Ju-Hyun Yu
- Center for Bio-based Chemistry, Green Chemistry & Engineering Division, Korea Research Institute of Chemical Technology, P.O. Box 107, 141 Gajeong-ro, Yuseong-gu, Daejeon 305-600, Republic of Korea.
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291
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Lin X, Qiu X, Yuan L, Li Z, Lou H, Zhou M, Yang D. Lignin-based polyoxyethylene ether enhanced enzymatic hydrolysis of lignocelluloses by dispersing cellulase aggregates. BIORESOURCE TECHNOLOGY 2015; 185:165-70. [PMID: 25768419 DOI: 10.1016/j.biortech.2015.02.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/12/2015] [Accepted: 02/13/2015] [Indexed: 05/08/2023]
Abstract
Water-soluble lignin-based polyoxyethylene ether (EHL-PEG), prepared from enzymatic hydrolysis lignin (EHL) and polyethylene glycol (PEG1000), was used to improve enzymatic hydrolysis efficiency of corn stover. The glucose yield of corn stover at 72h was increased from 16.7% to 70.1% by EHL-PEG, while increase in yield with PEG4600 alone was 52.3%. With the increase of lignin content, EHL-PEG improved enzymatic hydrolysis of microcrystalline cellulose more obvious than PEG4600. EHL-PEG could reduce at least 88% of the adsorption of cellulase on the lignin film measured by quartz crystal microbalance with dissipation monitoring (QCM-D), while reduction with PEG4600 was 43%. Cellulase aggregated at 1220nm in acetate buffer analyzed by dynamic light scattering. EHL-PEG dispersed cellulase aggregates and formed smaller aggregates with cellulase, thereby, reduced significantly nonproductive adsorption of cellulase on lignin and enhanced enzymatic hydrolysis of lignocelluloses.
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Affiliation(s)
- Xuliang Lin
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Xueqing Qiu
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China.
| | - Long Yuan
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Zihao Li
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Hongming Lou
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China.
| | - Mingsong Zhou
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Dongjie Yang
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
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292
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Chen HZ, Liu ZH. Steam explosion and its combinatorial pretreatment refining technology of plant biomass to bio-based products. Biotechnol J 2015; 10:866-85. [DOI: 10.1002/biot.201400705] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 02/13/2015] [Accepted: 03/25/2015] [Indexed: 11/09/2022]
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293
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Zhou Y, Chen H, Qi F, Zhao X, Liu D. Non-ionic surfactants do not consistently improve the enzymatic hydrolysis of pure cellulose. BIORESOURCE TECHNOLOGY 2015; 182:136-143. [PMID: 25689307 DOI: 10.1016/j.biortech.2015.01.137] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/27/2015] [Accepted: 01/30/2015] [Indexed: 05/18/2023]
Abstract
Non-ionic surfactants have been frequently reported to improve the enzymatic hydrolysis of pretreated lignocellulosic biomass and pure cellulose. However, how the hydrolysis condition, substrate structure and cellulase formulation affect the beneficial action of surfactants has not been well elucidated. In this work, it was found that the enzymatic hydrolysis of pure cellulose was not consistently improved by surfactants. Contrarily, high surfactant concentration, e.g. 5 g/L, which greatly improved the hydrolysis of dilute acid pretreated substrates, actually showed notable inhibition to pure cellulose conversion in the late phase of hydrolysis. Under an optimal hydrolysis condition, the improvement by surfactant was limited, but under harsh conditions surfactant indeed could enhance cellulose conversion. It was proposed that non-ionic surfactants could interact with substrates and cellulases to impact the adsorption behaviors of cellulases. Therefore, the beneficial action of surfactants on pure cellulose hydrolysis is influenced by hydrolysis condition, cellulose structural features and cellulase formulation.
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Affiliation(s)
- Yan Zhou
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Hongmei Chen
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Feng Qi
- College of Life Sciences/Engineering Research Center of Industrial Microbiology, Fujian Normal University, Fuzhou 350108, China
| | - Xuebing Zhao
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
| | - Dehua Liu
- Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
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294
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Shi F, Xiang H, Li Y. Combined pretreatment using ozonolysis and ball milling to improve enzymatic saccharification of corn straw. BIORESOURCE TECHNOLOGY 2015; 179:444-451. [PMID: 25569033 DOI: 10.1016/j.biortech.2014.12.063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 05/23/2023]
Abstract
Two clean pretreatments, ozonolysis (OZ) and planetary ball milling (BM) were applied separately and in combination to improve the enzymatic hydrolysis of corn straw. Pretreatment of corn straw by OZ and BM alone improved the enzymatic hydrolysis significantly, primarily through delignification and decrystallization of cellulose, respectively. When combined, OZ-BM and BM-OZ pretreatments made the enzymatic hydrolysis more efficient. The glucose and xylose yield of corn straw treated with OZ for 90 min followed by BM for 8 min (OZ90-BM8) reached to 407.8 and 101.9 mg/g-straw, respectively under cellulase loading of 15 FPU/g-straw, which was fivefold more than that of untreated straw. Under much lower cellulase loading of 1.5 FPU/g-straw, the glucose and xylose yield of treated straw OZ90-BM8 remained at 416.0 and 108.4 mg/g-straw, respectively, while the yield of untreated straw decreased. These findings indicate that the combined OZ-BM can be used as a promising pretreatment for corn straw.
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Affiliation(s)
- Feng Shi
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China.
| | - Heji Xiang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yongfu Li
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
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295
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Kapoor M, Raj T, Vijayaraj M, Chopra A, Gupta RP, Tuli DK, Kumar R. Structural features of dilute acid, steam exploded, and alkali pretreated mustard stalk and their impact on enzymatic hydrolysis. Carbohydr Polym 2015; 124:265-73. [PMID: 25839820 DOI: 10.1016/j.carbpol.2015.02.044] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/12/2015] [Accepted: 02/22/2015] [Indexed: 11/26/2022]
Abstract
To overcome the recalcitrant nature of biomass several pretreatment methodologies have been explored to make it amenable to enzymatic hydrolysis. These methodologies alter cell wall structure primarily by removing/altering hemicelluloses and lignin. In this work, alkali, dilute acid, steam explosion pretreatment are systematically studied for mustard stalk. To assess the structural variability after pretreatment, chemical analysis, surface area, crystallinity index, accessibility of cellulose, FT-IR and thermal analysis are conducted. Although the extent of enzymatic hydrolysis varies upon the methodologies used, nevertheless, cellulose conversion increases from <10% to 81% after pretreatment. Glucose yield at 2 and 72h are well correlated with surface area and maximum adsorption capacity. However, no such relationship is observed for xylose yield. Mass balance of the process is also studied. Dilute acid pretreatment is the best methodology in terms of maximum sugar yield at lower enzyme loading.
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Affiliation(s)
- Manali Kapoor
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | - Tirath Raj
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | - M Vijayaraj
- Nanotechnology Division, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | - Anju Chopra
- Analytical Division, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | - Ravi P Gupta
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | - Deepak K Tuli
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | - Ravindra Kumar
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India.
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296
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Castillo RDP, Araya J, Troncoso E, Vinet S, Freer J. Fourier transform infrared imaging and microscopy studies of Pinus radiata pulps regarding the simultaneous saccharification and fermentation process. Anal Chim Acta 2015; 866:10-20. [PMID: 25732688 DOI: 10.1016/j.aca.2015.01.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 10/24/2022]
Abstract
The distribution and chemical patterns of lignocellulosic components at microscopic scale and their effect on the simultaneous saccharification and fermentation process (SSF) in the production of bioethanol from Pinus radiata pulps were analyzed by the application of diverse microscopical techniques, including scanning electronic microscopy (SEM), confocal laser scanning microscopy (CLSM) and attenuated total reflectance (ATR) - Fourier transform infrared microspectroscopy. This last technique was accompanied with multivariate methods, including principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS) to evaluate the distribution patterns and to generate pure spectra of the lignocellulosic components of fibers. The results indicate that the information obtained by the techniques is complementary (ultrastructure, confocality and chemical characterization) and that the distribution of components affects the SSF yield, identifying lignin coalescence droplets as a characteristic factor to increase the SSF yield. Therefore, multivariate analysis of the infrared spectra enabled the in situ identification of the cellulose, lignin and lignin-carbohydrates arrangements. These techniques could be used to investigate the lignocellulosic components distribution and consequently their recalcitrance in many applications where minimal sample manipulation and microscale chemical information is required.
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Affiliation(s)
- Rosario Del P Castillo
- Faculty of Pharmacy, University of Concepcion, Concepcion, Chile; Biotechnology Center, University of Concepcion, Concepcion, Chile.
| | - Juan Araya
- Faculty of Pharmacy, University of Concepcion, Concepcion, Chile; Biotechnology Center, University of Concepcion, Concepcion, Chile
| | - Eduardo Troncoso
- Consorcio Bioenercel S.A, University of Concepcion, Concepcion, Chile
| | - Silenne Vinet
- Biotechnology Center, University of Concepcion, Concepcion, Chile; Faculty of Chemical Sciences, University of Concepcion, Concepcion, Chile
| | - Juanita Freer
- Biotechnology Center, University of Concepcion, Concepcion, Chile; Faculty of Chemical Sciences, University of Concepcion, Concepcion, Chile
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297
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Dong L, Zhao X, Liu D. Kinetic modeling of atmospheric formic acid pretreatment of wheat straw with “potential degree of reaction” models. RSC Adv 2015. [DOI: 10.1039/c4ra14634d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Potential degree of reaction models, which are developed based on the multilayered structure of plant cell wall, have been found applicable as general models for describing the kinetics of various chemical pretreatments of different biomass feedstocks.
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Affiliation(s)
- Lei Dong
- Institute of Applied Chemistry
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Xuebing Zhao
- Institute of Applied Chemistry
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Dehua Liu
- Institute of Applied Chemistry
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
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298
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Sun SL, Sun SN, Wen JL, Zhang XM, Peng F, Sun RC. Assessment of integrated process based on hydrothermal and alkaline treatments for enzymatic saccharification of sweet sorghum stems. BIORESOURCE TECHNOLOGY 2015; 175:473-9. [PMID: 25459857 DOI: 10.1016/j.biortech.2014.10.111] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 10/20/2014] [Accepted: 10/21/2014] [Indexed: 05/15/2023]
Abstract
In this study, sweet sorghum stem was subjected to hydrothermal pretreatment (HTP) and alkaline post-treatment to enhance its saccharification ratio by reducing its recalcitrance. The results showed that the HTP (110-210°C, 0.5-2.0h) significantly degraded hemicelluloses, and the pretreatment at the temperature higher than 190°C led to the partial degradation of the cellulose. As compared to the sole HTP, the integrated process removed most of lignin and hemicelluloses, which incurred a higher cellulose saccharification ratio. Under an optimum condition evaluated (HTP at 170°C for 0.5h and subsequent 2% NaOH treatment), 77.5% saccharification ratio was achieved, which was 1.8, 2.0 and 5.5 times as compared to the only HTP pretreated substrates, alkaline treated substrates alone and the raw material without pretreatment, respectively. Clearly, the integrated process can be considered as a promising approach to achieve an efficient conversion of lignocellulose to fermentable glucose.
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Affiliation(s)
- Shao-Long Sun
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, China
| | - Shao-Ni Sun
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, China
| | - Jia-Long Wen
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, China
| | - Xue-Ming Zhang
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, China
| | - Feng Peng
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, China.
| | - Run-Cang Sun
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, China
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299
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Yu H, You Y, Lei F, Liu Z, Zhang W, Jiang J. Comparative study of alkaline hydrogen peroxide and organosolv pretreatments of sugarcane bagasse to improve the overall sugar yield. BIORESOURCE TECHNOLOGY 2015; 187:161-166. [PMID: 25846186 DOI: 10.1016/j.biortech.2015.03.123] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 05/17/2023]
Abstract
Green liquor (GL) combined with H2O2 (GL-H2O2) and green liquor (GL) combined with ethanol (GL-ethanol) were chosen for treating sugarcane bagasse. Results showed that the glucose yield (calculated from the glucose content as a percentage of the theoretical glucose available in the substrates)of sugarcane bagasse from GL-ethanol pretreatment (97.7%) was higher than that from GL-H2O2 pretreatment (41.7%) after 72h hydrolysis with 18 filter paper unit (FPU)/g-cellulose for cellulase, 27,175 cellobiase units (CBU)/g-cellulose for β-glucosidase. Furthermore, about 94.1% of xylan was converted to xylose after GL-ethanol pretreatment without additional xylanase, while the xylose yield was only 29.2% after GL-H2O2 pretreatment. Scanning electron microscopy showed that GL-ethanol pretreatment could break up the fiber severely. Moreover, GL-ethanol pretreated substrate was more accessible to cellulase and more hydrophilic than that of GL-H2O2 pretreated. Therefore, GL-ethanol pretreatment is a promising method for improving the overall sugar (glucose and xylan) yield of sugarcane bagasse.
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Affiliation(s)
- Hailong Yu
- Department of Chemistry and Chemical Engineering, MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083, China
| | - Yanzhi You
- Department of Chemistry and Chemical Engineering, MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083, China
| | - Fuhou Lei
- GuangXi Key Laboratory of Chemistry and Engineering of Forest Products, Nanning 530006, China
| | - Zuguang Liu
- GuangXi Key Laboratory of Chemistry and Engineering of Forest Products, Nanning 530006, China
| | - Weiming Zhang
- Nanjing Institute for the Comprehensive Utilization of Wild Plant, Nanjing 210042, China
| | - Jianxin Jiang
- Department of Chemistry and Chemical Engineering, MOE Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Forestry University, Beijing 100083, China
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300
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Lebaz N, Cockx A, Spérandio M, Morchain J. Population balance approach for the modelling of enzymatic hydrolysis of cellulose. CAN J CHEM ENG 2014. [DOI: 10.1002/cjce.22088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Noureddine Lebaz
- Toulouse White Biotechnology; 3 rue des satellites 31400 Toulouse France
- Université de Toulouse; INSA; UPS; INP; LISBP; 135 Avenue de Rangueil F-31077 Toulouse France
- INRA; UMR792 Ingénierie des Systèmes Biologiques et des Procédés; F-31400 Toulouse France
- CNRS; UMR5504; F-31400 Toulouse France
| | - Arnaud Cockx
- Université de Toulouse; INSA; UPS; INP; LISBP; 135 Avenue de Rangueil F-31077 Toulouse France
- INRA; UMR792 Ingénierie des Systèmes Biologiques et des Procédés; F-31400 Toulouse France
- CNRS; UMR5504; F-31400 Toulouse France
| | - Mathieu Spérandio
- Université de Toulouse; INSA; UPS; INP; LISBP; 135 Avenue de Rangueil F-31077 Toulouse France
- INRA; UMR792 Ingénierie des Systèmes Biologiques et des Procédés; F-31400 Toulouse France
- CNRS; UMR5504; F-31400 Toulouse France
| | - Jérôme Morchain
- Université de Toulouse; INSA; UPS; INP; LISBP; 135 Avenue de Rangueil F-31077 Toulouse France
- INRA; UMR792 Ingénierie des Systèmes Biologiques et des Procédés; F-31400 Toulouse France
- CNRS; UMR5504; F-31400 Toulouse France
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