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Fang X, Li Q, Lin Y, Lin X, Dai Y, Guo Z, Pan D. Screening of a microbial consortium for selective degradation of lignin from tree trimmings. BIORESOURCE TECHNOLOGY 2018; 254:247-255. [PMID: 29413930 DOI: 10.1016/j.biortech.2018.01.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 05/27/2023]
Abstract
To acquire microbial consortia with effectively precedent degradation of lignin, samples obtained from rotten trunks, rotten stumps and soil near it were screened and isolated after generations of subculture. The dynamic change illustrated that their community structures were affected by pH and tended to be stable after 6 days' cultivation. The desired one, named DM-1, was gained through successive cultivation for over 5 generations, whose high selectivity in lignin degradation was observed within 16 days' cultivation (SV = 2.78). Meanwhile, a remarkable reduction in the fiber crystallinity of tree trimmings (10.35%) resulted from the bio-degradation of DM-1, displayed a greater exposure of cellulose by selective removal of lignin. The diversity analysis of DM-1 was investigated by PCR amplification and 16S rDNA sequencing, indicated that mesorhizobium, cellulosimicrobium, pandoraea, achromobacter and stenotrophomones were the predominant genera. Furthermore, fungi (3 strains), bacteria (4 strains) and actinomycetes (5 strains) constituted 12 strains in total were gained by plate isolation from DM-1.
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Affiliation(s)
- Xiuxiu Fang
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
| | - Qiumin Li
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China; School of Agriculture and Food Science, Belfield Campus, University College Dublin, Dublin 4, Ireland
| | - Yunqin Lin
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China; Integrate Microbiology Research Center, South China Agricultural University, Guangzhou, Guangdong 510642, PR China.
| | - Xinlei Lin
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
| | - Yiqi Dai
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
| | - Zexiang Guo
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
| | - Dezhao Pan
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, Guangdong 510642, PR China
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102
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Teramura H, Sasaki K, Oshima T, Kawaguchi H, Ogino C, Sazuka T, Kondo A. Effective usage of sorghum bagasse: Optimization of organosolv pretreatment using 25% 1-butanol and subsequent nanofiltration membrane separation. BIORESOURCE TECHNOLOGY 2018; 252:157-164. [PMID: 29324275 DOI: 10.1016/j.biortech.2017.12.100] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/27/2017] [Accepted: 12/28/2017] [Indexed: 06/07/2023]
Abstract
We investigated the use of low concentrations of butanol (<40%, all v/v) as an organosolv pretreatment to fractionate lignocellulosic biomass into cellulose, hemicellulose, and lignin. The pretreatment conditions were optimized for sorghum bagasse by focusing on four parameters: butanol concentration, sulfuric acid concentration, pretreatment temperature, and pretreatment time. A butanol concentration of 25% or higher together with 0.5% or higher acid was effective for removing lignin while retaining most of the cellulose in the solid fraction. The highest cellulose (84.9%) and low lignin (15.3%) content were obtained after pretreatment at 200 °C for 60 min. Thus, pretreatment comprising 25% butanol, 0.5% acid, 200 °C, and 60 min process time was considered optimal. Enzymatic saccharification and fermentation by Saccharomyces cerevisiae produced 61.9 g/L ethanol from 200 g/L solid fraction obtained following pretreatment, and 10.2 g/L ethanol was obtained from the liquid fraction by xylose-utilizing S. cerevisiae following membrane nanofiltration to remove butanol.
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Affiliation(s)
- Hiroshi Teramura
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Kengo Sasaki
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Tomoko Oshima
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Hideo Kawaguchi
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Chiaki Ogino
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Takashi Sazuka
- Bioscience and Biotechnology Center, Nagoya University, Furocho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan; Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
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103
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Schückel J, Kračun SK. Two-Dimensional High-Throughput Endo-Enzyme Screening Assays Based on Chromogenic Polysaccharide Hydrogel and Complex Biomass Substrates. Methods Mol Biol 2018; 1796:201-217. [PMID: 29856056 DOI: 10.1007/978-1-4939-7877-9_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this chapter, we present a two-dimensional approach for high-throughput screening of endo-cellulases as well as other endo-acting enzymes. The method is based on chromogenic substrates, produced either from purified or complex material, providing valuable information about enzyme activity toward its target as well as that same target in a context of complex natural material normally encountered in bioindustrial settings. The enzymes that can be tested using this assay can be from virtually any source: in purified form, directly from microbial cultures or even from raw materials, enabling study of the interplay between enzyme mixtures such as synergistic or inhibitory effects. By using the method of analysis described in this chapter, enzymes can be screened and evaluated quickly and information pertinent to both the inherent properties of the enzyme itself as well as predictions about its performance on complex biomass samples can be obtained.
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104
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Khatri V, Meddeb-Mouelhi F, Adjallé K, Barnabé S, Beauregard M. Determination of optimal biomass pretreatment strategies for biofuel production: investigation of relationships between surface-exposed polysaccharides and their enzymatic conversion using carbohydrate-binding modules. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:144. [PMID: 29796085 PMCID: PMC5960114 DOI: 10.1186/s13068-018-1145-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/09/2018] [Indexed: 05/03/2023]
Abstract
BACKGROUND Pretreatment of lignocellulosic biomass (LCB) is a key step for its efficient bioconversion into ethanol. Determining the best pretreatment and its parameters requires monitoring its impacts on the biomass material. Here, we used fluorescent protein-tagged carbohydrate-binding modules method (FTCM)-depletion assay to study the relationship between surface-exposed polysaccharides and enzymatic hydrolysis of LCB. RESULTS Our results indicated that alkali extrusion pretreatment led to the highest hydrolysis rates for alfalfa stover, cattail stems and flax shives, despite its lower lignin removal efficiency compared to alkali pretreatment. Corn crop residues were more sensitive to alkali pretreatments, leading to higher hydrolysis rates. A clear relationship was consistently observed between total surface-exposed cellulose detected by the FTCM-depletion assay and biomass enzymatic hydrolysis. Comparison of bioconversion yield and total composition analysis (by NREL/TP-510-42618) of LCB prior to or after pretreatments did not show any close relationship. Lignin removal efficiency and total cellulose content (by NREL/TP-510-42618) led to an unreliable prediction of enzymatic polysaccharide hydrolysis. CONCLUSIONS Fluorescent protein-tagged carbohydrate-binding modules method (FTCM)-depletion assay provided direct evidence that cellulose exposure is the key determinant of hydrolysis yield. The clear and robust relationships that were observed between the cellulose accessibility by FTCM probes and enzymatic hydrolysis rates change could be evolved into a powerful prediction tool that might help develop optimal biomass pretreatment strategies for biofuel production.
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Affiliation(s)
- Vinay Khatri
- Centre de recherche sur les matériaux lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada
- PROTEO, Université Laval, Québec, QC G1V 4G2 Canada
| | - Fatma Meddeb-Mouelhi
- Centre de recherche sur les matériaux lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada
- PROTEO, Université Laval, Québec, QC G1V 4G2 Canada
| | - Kokou Adjallé
- Centre de recherche sur les matériaux lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada
| | - Simon Barnabé
- Centre de recherche sur les matériaux lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada
| | - Marc Beauregard
- Centre de recherche sur les matériaux lignocellulosiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières, QC G9A 5H7 Canada
- PROTEO, Université Laval, Québec, QC G1V 4G2 Canada
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105
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Yoav S, Salame TM, Feldman D, Levinson D, Ioelovich M, Morag E, Yarden O, Bayer EA, Hadar Y. Effects of cre1 modification in the white-rot fungus Pleurotus ostreatus PC9: altering substrate preference during biological pretreatment. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:212. [PMID: 30065786 PMCID: PMC6062969 DOI: 10.1186/s13068-018-1209-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 07/18/2018] [Indexed: 05/16/2023]
Abstract
BACKGROUND During the process of bioethanol production, cellulose is hydrolyzed into its monomeric soluble units. For efficient hydrolysis, a chemical and/or mechanical pretreatment step is required. Such pretreatment is designed to increase enzymatic digestibility of the cellulose chains inter alia by de-crystallization of the cellulose chains and by removing barriers, such as lignin from the plant cell wall. Biological pretreatment, in which lignin is decomposed or modified by white-rot fungi, has also been considered. One disadvantage in biological pretreatment, however, is the consumption of the cellulose by the fungus. Thus, fungal species that attack lignin with only minimal cellulose loss are advantageous. The secretomes of white-rot fungi contain carbohydrate-active enzymes (CAZymes) including lignin-modifying enzymes. Thus, modification of secretome composition can alter the ratio of lignin/cellulose degradation. RESULTS Pleurotus ostreatus PC9 was genetically modified to either overexpress or eliminate (by gene replacement) the transcriptional regulator CRE1, known to act as a repressor in the process of carbon catabolite repression. The cre1-overexpressing transformant demonstrated lower secreted cellulolytic activity and slightly increased selectivity (based on the chemical composition of pretreated wheat straw), whereas the knockout transformant demonstrated increased cellulolytic activity and significantly reduced residual cellulose, thereby displaying lower selectivity. Pretreatment of wheat straw using the wild-type PC9 resulted in 2.8-fold higher yields of soluble sugar compared to untreated wheat straw. The overexpression transformant showed similar yields (2.6-fold), but the knockout transformant exhibited lower yields (1.2-fold) of soluble sugar. Based on proteomic secretome analysis, production of numerous CAZymes was affected by modification of the expression level of cre1. CONCLUSIONS The gene cre1 functions as a regulator for expression of fungal CAZymes active against plant cell wall lignocelluloses, hence altering the substrate preference of the fungi tested. While the cre1 knockout resulted in a less efficient biological pretreatment, i.e., less saccharification of the treated biomass, the converse manipulation of cre1 (overexpression) failed to improve efficiency. Despite the inverse nature of the two genetic alterations, the expected "mirror image" (i.e., opposite regulatory response) was not observed, indicating that the secretion level of CAZymes, was not exclusively dependent on CRE1 activity.
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Affiliation(s)
- Shahar Yoav
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100 Israel
| | - Tomer M. Salame
- Flow Cytometry Unit, Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Daria Feldman
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100 Israel
| | - Dana Levinson
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100 Israel
| | | | - Ely Morag
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100 Israel
| | - Edward A. Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 76100 Israel
| | - Yitzhak Hadar
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100 Israel
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106
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Lara-Flores AA, Araújo RG, Rodríguez-Jasso RM, Aguedo M, Aguilar CN, Trajano HL, Ruiz HA. Bioeconomy and Biorefinery: Valorization of Hemicellulose from Lignocellulosic Biomass and Potential Use of Avocado Residues as a Promising Resource of Bioproducts. ENERGY, ENVIRONMENT, AND SUSTAINABILITY 2018. [DOI: 10.1007/978-981-10-7431-8_8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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107
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Naidu DS, Hlangothi SP, John MJ. Bio-based products from xylan: A review. Carbohydr Polym 2018; 179:28-41. [DOI: 10.1016/j.carbpol.2017.09.064] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 09/08/2017] [Accepted: 09/20/2017] [Indexed: 01/12/2023]
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108
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Quehenberger J, Shen L, Albers SV, Siebers B, Spadiut O. Sulfolobus - A Potential Key Organism in Future Biotechnology. Front Microbiol 2017; 8:2474. [PMID: 29312184 PMCID: PMC5733018 DOI: 10.3389/fmicb.2017.02474] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/28/2017] [Indexed: 11/13/2022] Open
Abstract
Extremophilic organisms represent a potentially valuable resource for the development of novel bioprocesses. They can act as a source for stable enzymes and unique biomaterials. Extremophiles are capable of carrying out microbial processes and biotransformations under extremely hostile conditions. Extreme thermoacidophilic members of the well-characterized genus Sulfolobus are outstanding in their ability to thrive at both high temperatures and low pH. This review gives an overview of the biological system Sulfolobus including its central carbon metabolism and the development of tools for its genetic manipulation. We highlight findings of commercial relevance and focus on potential industrial applications. Finally, the current state of bioreactor cultivations is summarized and we discuss the use of Sulfolobus species in biorefinery applications.
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Affiliation(s)
- Julian Quehenberger
- Research Division Biochemical Engineering, Faculty of Technical Chemistry, Institute of Chemical, Environmental and Biological Engineering, Vienna University of Technology, Vienna, Austria
| | - Lu Shen
- Department of Molecular Enzyme Technology and Biochemistry, Faculty of Chemistry – Biofilm Centre, University of Duisburg-Essen, Essen, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II-Microbiology, Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Bettina Siebers
- Department of Molecular Enzyme Technology and Biochemistry, Faculty of Chemistry – Biofilm Centre, University of Duisburg-Essen, Essen, Germany
| | - Oliver Spadiut
- Research Division Biochemical Engineering, Faculty of Technical Chemistry, Institute of Chemical, Environmental and Biological Engineering, Vienna University of Technology, Vienna, Austria
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109
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de la Torre I, Ravelo M, Segarra S, Tortajada M, Santos VE, Ladero M. Study on the effects of several operational variables on the enzymatic batch saccharification of orange solid waste. BIORESOURCE TECHNOLOGY 2017; 245:906-915. [PMID: 28931207 DOI: 10.1016/j.biortech.2017.08.094] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
In this work, batch enzyme-aided extraction and enzymatic saccharification of blade-milled orange waste was studied. The operation variables for this process were thoroughly analysed. It was determined that batch runs with initial pH values of 5.0 and 5.2 controlled during the first hour, 50°C and 300-500r.p.m. agitation resulted in the best yields, with a limited total and partial first-order enzyme deactivation (for cellulases and polygalacturonidase, respectively). Orange peel waste (OPW) at 6.7% w/w dry solid, 0.22 filter paper units (FPU)/g DS and proportional activities of other enzymes led to over 40g/L free monosaccharides and global yields to glucose over 80%. When using 10.1% w/w DS in these conditions, glucose yield was 63%, with total monosaccharide concentration on top of 50g/L. Similar concentrations were obtained by additional partial drying of OPW to 60% humidity at DS/L ratios near 7.5% (glucose yield >80%).
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Affiliation(s)
- Isabel de la Torre
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Marianela Ravelo
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Silvia Segarra
- BIOPOLIS, S.L., Parc Científic Universitat de València, 46980, Paterna, Valencia, Spain
| | - Marta Tortajada
- BIOPOLIS, S.L., Parc Científic Universitat de València, 46980, Paterna, Valencia, Spain
| | - Victoria E Santos
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Miguel Ladero
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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110
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Xie C, Gong W, Yang Q, Zhu Z, Yan L, Hu Z, Peng Y. White-rot fungi pretreatment combined with alkaline/oxidative pretreatment to improve enzymatic saccharification of industrial hemp. BIORESOURCE TECHNOLOGY 2017; 243:188-195. [PMID: 28662388 DOI: 10.1016/j.biortech.2017.06.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/12/2017] [Accepted: 06/13/2017] [Indexed: 06/07/2023]
Abstract
White-rot fungi combined with alkaline/oxidative (A/O) pretreatments of industrial hemp woody core were proposed to improve enzymatic saccharification. In this study, hemp woody core were treated with only white rot fungi, only A/O and combined with the two methods. The results showed that Pleurotus eryngii (P. eryngii) was the most effective fungus for pretreatment. Reducing sugars yield was 329mg/g with 30 Filter Paper Unit (FPU)/g cellulase loading when treated 21day. In the A/O groups, the results showed that when treated with 3% NaOH and 3% H2O2, the yield of reducing sugars was 288mg/g with 30FPU/g cellulase loading. After combination pretreatment with P. eryngii and A/O pretreatment, the reducing sugar yield from enzymatic hydrolysis of combined sample increased 1.10-1.29-fold than that of bio-treated or A/O pretreatment sample at the same conditions, suggesting that P. eryngii combined with A/O pretreatment was an effective method to improve enzyme hydrolysis.
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Affiliation(s)
- Chunliang Xie
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Wenbing Gong
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Qi Yang
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Zuohua Zhu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Li Yan
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Zhenxiu Hu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China
| | - Yuande Peng
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, PR China.
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111
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Effects of alkaline catalysts on acetone-based organosolv pretreatment of rice straw. 3 Biotech 2017; 7:340. [PMID: 28955637 DOI: 10.1007/s13205-017-0969-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/07/2017] [Indexed: 10/18/2022] Open
Abstract
Organosolv is an effective pretreatment strategy for increasing digestibility of lignocellulosic materials owing to selectivity of solvents on separating biopolymeric constituents of plant biomass. In the present work, a novel low-temperature alkali-catalyzed organosolv pretreatment of rice straw was studied. The effects of alkaline catalysts (i.e., NaOH, ammonia, and tri-ethylamine) and solvent types (i.e., acetone, ethanol, and water) were carried out. Addition of alkalis led to increasing sugar from enzymatic hydrolysis while acetone was found to be superior to ethanol and water on selectivity towards cellulose preservation. The optimal alkaline-catalyzed pretreatment reaction contained 5% (w/v) NaOH in an aqueous-acetone mixture (1:4) at 80 °C for 5 min. A glucose yield of 913 mg/g of pretreated biomass was achieved, equivalent to a maximal glucose recovery of 93.0% from glucan in the native biomass. Scanning electron microscope revealed efficient removal of non-cellulosic components, resulting in exposed cellulose microfibers with a reduced crystallite size as determined by X-ray diffraction. With potential on obtaining high-quality lignin, the work demonstrated potential of the novel low-temperature alkaline-catalyzed acetone-based organosolv process for pretreatment of lignocellulosic materials in biorefineries.
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112
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Wood IP, Garcia-Gutierrez E, Wellner N, Waldron KW. Feedstock selection for polymer and chemical production: feedstock-specific recalcitrance. Faraday Discuss 2017; 202:391-402. [PMID: 28682402 DOI: 10.1039/c7fd00044h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Plant cell wall materials derived from a range of waste biomass sources have great potential as a source of sustainable alternatives to petrochemicals. Perhaps the most straightforward way of realising this potential would be to hydrolyse the most efficiently fermentable polymers into their constituent sugars and use yeast to ferment these into useful chemicals. However, it also makes sense to pre-extract components which have a greater value in polymeric form. This is particularly true for non-cellulosic polymers, which are rich in poorly-fermentable pentose sugars. Liquid hot water (LHW) pretreatment can be used to extract non-cellulosic carbohydrates in a cost-effective manner, leaving a cellulose-rich substrate which is easier to hydrolyse using commercial cellulases. However, inherent differences in the plant cell wall structure and composition mean that some biomass sources may be more suitable for exploitation than others. Here, we examine eight different feedstocks (two each from hardwood, softwood, cereal straws and dicotyledonous crops), expose them to 26 different LHW pretreatment conditions and hydrolyse the entire pretreated slurry with a commercial cellulase. This enables side-by-side comparisons, in terms of saccharification yield, of the feedstocks. The results clearly demonstrate considerable differences in suitability between the feedstocks, in relation to the quantity of products released and the processes needed to obtain them.
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Affiliation(s)
- Ian P Wood
- Quadram Institute Bioscience, Norwich Research Park, Colney, Norwich NR47UA, UK.
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113
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Industrial Biotechnology: A Unique Potential for Pollution Prevention. Ind Biotechnol (New Rochelle N Y) 2017. [DOI: 10.1089/ind.2017.29088.bio] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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114
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Goldmann WM, Ahola J, Mikola M, Tanskanen J. Formic acid aided hot water extraction of hemicellulose from European silver birch (Betula pendula) sawdust. BIORESOURCE TECHNOLOGY 2017; 232:176-182. [PMID: 28231535 DOI: 10.1016/j.biortech.2017.02.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/06/2017] [Accepted: 02/08/2017] [Indexed: 06/06/2023]
Abstract
Hemicellulose has been extracted from birch (Betula pendula) sawdust by formic acid aided hot water extraction. The maximum amount of hemicellulose extracted was about 70mol% of the total hemicellulose content at 170°C, measured as the combined yield of xylose and furfural. Lower temperatures (130 and 140°C) favored hemicellulose hydrolysis rather than cellulose hydrolysis, even though the total hemicellulose yield was less than at 170°C. It was found that formic acid greatly increased the hydrolysis of hemicellulose to xylose and furfural at the experimental temperatures. The amount of lignin in the extract remained below the detection limit of the analysis (3g/L) in all cases. Formic acid aided hot water extraction is a promising technique for extracting hemicellulose from woody biomass, while leaving a solid residue with low hemicellulose content, which can be delignified to culminate in the three main isolated lignocellulosic fractions: cellulose, hemicellulose, and lignin.
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Affiliation(s)
- Werner Marcelo Goldmann
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, Oulu 90014, Finland.
| | - Juha Ahola
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, Oulu 90014, Finland
| | - Marja Mikola
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, Oulu 90014, Finland
| | - Juha Tanskanen
- Chemical Process Engineering, Faculty of Technology, University of Oulu, P.O. Box 4300, Oulu 90014, Finland
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115
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Mohapatra S, Dandapat SJ, Thatoi H. Physicochemical characterization, modelling and optimization of ultrasono-assisted acid pretreatment of two Pennisetum sp. using Taguchi and artificial neural networking for enhanced delignification. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 187:537-549. [PMID: 27865731 DOI: 10.1016/j.jenvman.2016.09.060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/16/2016] [Accepted: 09/18/2016] [Indexed: 06/06/2023]
Abstract
Acid as well as ultrasono-assisted acid pretreatment of lignocellulosic biomass of two Pennisetum sp.; Denanath grass (DG) and Hybrid Napier grass (HNG) have been investigated for enhanced delignification and maximum exposure of cellulose for production of bioethanol. Screening of pretreatment with different acids such as H2SO4, HCl, H3PO4 and H2NO3 were optimized for different temperature, soaking time and acid concentrations using Taguchi orthogonal array and the data obtained were statistically validated using artificial neural networking. HCl was found to be the most effective acid for pretreatment of both the Pennisetum sp. The optimized conditions of HCl pretreatment were acid concentration of 1% and 1.5%, soaking time 130 and 50 min and temperature 121 °C and 110 °C which yielded maximum delignification of 33.0% and 33.8% for DG and HNG respectively. Further ultrosono-assisted HCl pretreatment with a power supply of 100 W, temperature of 353 K, and duty cycle of 70% has resulted in significantly higher delignification of 80.4% and 82.1% for both DG and HNG respectively than that of acid pretreatment. Investigation using SEM, FTIR and autofloresence microscopy for both acid and ultrasono-assisted acid pretreatment lignocellulosic biomass revealed conformational changes of pretreated lignocellulosic biomass with decreased lignin content and increased exposure of cellulose, with greater effectiveness in case of ultrasono assisted acid pretreatment condition.
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Affiliation(s)
- Sonali Mohapatra
- Department of Biotechnology, College of Engineering and Technology, Biju Pattnaik University of Technology, Bhubaneswar, 751003, India
| | - Snigdha Jyotsna Dandapat
- Department of Biotechnology, College of Engineering and Technology, Biju Pattnaik University of Technology, Bhubaneswar, 751003, India
| | - Hrudayanath Thatoi
- Department of Biotechnology, North Orissa University, Sriramchandra Vihar, Takatpur, Baripada, 757003, Odisha, India.
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Zhong C, Jia H, Wei P. Enhanced saccharification of wheat straw with the application of ultrasonic-assisted quaternary ammonium hydroxide pretreatment. Process Biochem 2017. [DOI: 10.1016/j.procbio.2016.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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117
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Duwe A, Tippkötter N, Ulber R. Lignocellulose-Biorefinery: Ethanol-Focused. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 166:177-215. [PMID: 29071401 DOI: 10.1007/10_2016_72] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The development prospects of the world markets for petroleum and other liquid fuels are diverse and partly contradictory. However, comprehensive changes for the energy supply of the future are essential. Notwithstanding the fact that there are still very large deposits of energy resources from a geological point of view, the finite nature of conventional oil reserves is indisputable. To reduce our dependence on oil, the EU, the USA, and other major economic zones rely on energy diversification. For this purpose, alternative materials and technologies are being sought, and is most obvious in the transport sector. The objective is to progressively replace fossil fuels with renewable and more sustainable fuels. In this respect, biofuels have a pre-eminent position in terms of their capability of blending with fossil fuels and being usable in existing cars without substantial modification. Ethanol can be considered as the primary renewable liquid fuel. In this chapter enzymes, micro-organisms, and processes for ethanol production based on renewable resources are described.
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Affiliation(s)
- A Duwe
- Institute of Bioprocess Engineering, University of Kaiserslautern, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany.
| | - N Tippkötter
- Institute of Bioprocess Engineering, University of Kaiserslautern, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany
| | - R Ulber
- Institute of Bioprocess Engineering, University of Kaiserslautern, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany
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118
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Chang KL, Chen XM, Han YJ, Wang XQ, Potprommanee L, Ning XA, Liu JY, Sun J, Peng YP, Sun SY, Lin YC. Synergistic effects of surfactant-assisted ionic liquid pretreatment rice straw. BIORESOURCE TECHNOLOGY 2016; 214:371-375. [PMID: 27155265 DOI: 10.1016/j.biortech.2016.04.113] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 05/24/2023]
Abstract
The aim of this work was to study an environmentally friendly method for pretreating rice straw by using 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as an ionic liquid (IL) assisted by surfactants. Different temperatures, reaction times, and surfactant concentrations were studied. Compared with [BMIM]Cl only pretreatment, the addition of 1% sodium dodecyl sulfate (SDS) and 1% cetyl trimethyl ammonium bromide (CTAB) increased lignin removal to 49.48% and 34.76%, respectively. Untreated and pretreated rice straw was thoroughly characterized through FTIR, XRD, and FE-SEM. Cellulose crystallinity and surface morphology of the rice straw were substantially altered after surfactant-assisted IL pretreatment. In conclusion, surfactant-assisted IL pretreatment is an effective method for producing fermentable sugars from lignocellulosic substrates.
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Affiliation(s)
- Ken-Lin Chang
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China; Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Xi-Mei Chen
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Ye-Ju Han
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Xiao-Qin Wang
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Laddawan Potprommanee
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Xun-An Ning
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Jing-Yong Liu
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Jian Sun
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Yen-Ping Peng
- Department of Environmental Science and Engineering, Tunghai University, Taichung, Taiwan
| | - Shui-Yu Sun
- School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, China
| | - Yuan-Chung Lin
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan.
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119
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Qing Q, Zhou L, Huang M, Guo Q, He Y, Wang L, Zhang Y. Improving enzymatic saccharification of bamboo shoot shell by alkalic salt pretreatment with H2O2. BIORESOURCE TECHNOLOGY 2016; 201:230-6. [PMID: 26675047 DOI: 10.1016/j.biortech.2015.11.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/19/2015] [Accepted: 11/21/2015] [Indexed: 05/25/2023]
Abstract
Pretreatment of bamboo shoot shell (BSS) by a combination of alkalic salts with hydrogen peroxide (H2O2) was evaluated for its delignification effect and for its ability to enhance enzymatic saccharification of pretreated solids. By comparing different alkalic salts, the combination of 9% Na3PO4·12H2O and 0.3g/g H2O2 (ASHP) was identified as an effective system that showed the highest delignification of 87.7% and the total reducing sugar yield of 97.1% when pretreated BSS at a solid to liquid ratio of 1/20 (w/w) at 80°C for 2h. The delignification effect and the disruption of the lignocelluloses structure by this novel pretreatment method were deduced to be the main reasons that led to enhanced enzymatic saccharification as supported by the chemical composition analysis and the results of SEM, FTIR and XRD analyses of the untreated and alkalic salt pretreated BSS.
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Affiliation(s)
- Qing Qing
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Linlin Zhou
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Meizi Huang
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Qi Guo
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Yucai He
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Liqun Wang
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China
| | - Yue Zhang
- Department of Biochemical Engineering, College of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou 213164, Jiangsu, China.
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Tan HT, Corbin KR, Fincher GB. Emerging Technologies for the Production of Renewable Liquid Transport Fuels from Biomass Sources Enriched in Plant Cell Walls. FRONTIERS IN PLANT SCIENCE 2016; 7:1854. [PMID: 28018390 PMCID: PMC5161040 DOI: 10.3389/fpls.2016.01854] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 11/24/2016] [Indexed: 05/15/2023]
Abstract
Plant cell walls are composed predominantly of cellulose, a range of non-cellulosic polysaccharides and lignin. The walls account for a large proportion not only of crop residues such as wheat straw and sugarcane bagasse, but also of residues of the timber industry and specialist grasses and other plants being grown specifically for biofuel production. The polysaccharide components of plant cell walls have long been recognized as an extraordinarily large source of fermentable sugars that might be used for the production of bioethanol and other renewable liquid transport fuels. Estimates place annual plant cellulose production from captured light energy in the order of hundreds of billions of tons. Lignin is synthesized in the same order of magnitude and, as a very large polymer of phenylpropanoid residues, lignin is also an abundant, high energy macromolecule. However, one of the major functions of these cell wall constituents in plants is to provide the extreme tensile and compressive strengths that enable plants to resist the forces of gravity and a broad range of other mechanical forces. Over millions of years these wall constituents have evolved under natural selection to generate extremely tough and resilient biomaterials. The rapid degradation of these tough cell wall composites to fermentable sugars is therefore a difficult task and has significantly slowed the development of a viable lignocellulose-based biofuels industry. However, good progress has been made in overcoming this so-called recalcitrance of lignocellulosic feedstocks for the biofuels industry, through modifications to the lignocellulose itself, innovative pre-treatments of the biomass, improved enzymes and the development of superior yeasts and other microorganisms for the fermentation process. Nevertheless, it has been argued that bioethanol might not be the best or only biofuel that can be generated from lignocellulosic biomass sources and that hydrocarbons with intrinsically higher energy densities might be produced using emerging and continuous flow systems that are capable of converting a broad range of plant and other biomasses to bio-oils through so-called 'agnostic' technologies such as hydrothermal liquefaction. Continued attention to regulatory frameworks and ongoing government support will be required for the next phase of development of internationally viable biofuels industries.
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Affiliation(s)
- Hwei-Ting Tan
- Centre for Tropical Crops and Biocommodities, Queensland University of Technology, BrisbaneQLD, Australia
| | - Kendall R. Corbin
- Centre for Marine Bioproducts Development, School of Medicine, Flinders University, Bedford ParkSA, Australia
| | - Geoffrey B. Fincher
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Agriculture, Food and Wine, University of Adelaide, Glen OsmondSA, Australia
- *Correspondence: Geoffrey B. Fincher,
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122
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Zhou S, Raouche S, Grisel S, Navarro D, Sigoillot JC, Herpoël-Gimbert I. Solid-state fermentation in multi-well plates to assess pretreatment efficiency of rot fungi on lignocellulose biomass. Microb Biotechnol 2015; 8:940-9. [PMID: 26249037 PMCID: PMC4621447 DOI: 10.1111/1751-7915.12307] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 06/01/2015] [Accepted: 06/10/2015] [Indexed: 12/01/2022] Open
Abstract
The potential of fungal pretreatment to improve fermentable sugar yields from wheat straw or Miscanthus was investigated. We assessed 63 fungal strains including 53 white-rot and 10 brown-rot fungi belonging to the Basidiomycota phylum in an original 12 day small-scale solid-state fermentation (SSF) experiment using 24-well plates. This method offers the convenience of one-pot processing of samples from SSF to enzymatic hydrolysis. The comparison of the lignocellulolytic activity profiles of white-rot fungi and brown-rot fungi showed different behaviours. The hierarchical clustering according to glucose and reducing sugars released from each biomass after 72 h enzymatic hydrolysis splits the set of fungal strains into three groups: efficient, no-effect and detrimental-effect species. The efficient group contained 17 species belonging to seven white-rot genera and one brown-rot genus. The yield of sugar released increased significantly (max. 62%) compared with non-inoculated controls for both substrates.
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Affiliation(s)
- Simeng Zhou
- INRA, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,Aix-Marseille Université, Polytech Marseille, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France
| | - Sana Raouche
- INRA, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,Aix-Marseille Université, Polytech Marseille, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France
| | - Sacha Grisel
- INRA, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,Aix-Marseille Université, Polytech Marseille, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France
| | - David Navarro
- INRA, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,Aix-Marseille Université, Polytech Marseille, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,International Centre for Microbial Resources collection-Filamentous Fungi, CIRM-CF, F-13009, Marseille, France
| | - Jean-Claude Sigoillot
- INRA, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,Aix-Marseille Université, Polytech Marseille, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France
| | - Isabelle Herpoël-Gimbert
- INRA, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France.,Aix-Marseille Université, Polytech Marseille, UMR 1163 Biodiversity and Biotechnology of Fungi, F-13009, Marseille, France
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