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Cazier EA, Pham TN, Cossus L, Abla M, Ilc T, Lawrence P. Exploring industrial lignocellulosic waste: Sources, types, and potential as high-value molecules. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 188:11-38. [PMID: 39094219 DOI: 10.1016/j.wasman.2024.07.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 07/22/2024] [Accepted: 07/24/2024] [Indexed: 08/04/2024]
Abstract
Lignocellulosic biomass has a promising role in a circular bioeconomy and may be used to produce valuable molecules for green chemistry. Lignocellulosic biomass, such as food waste, agricultural waste, wood, paper or cardboard, corresponded to 15.7% of all waste produced in Europe in 2020, and has a high potential as a secondary raw material for industrial processes. This review first presents industrial lignocellulosic waste sources, in terms of their composition, quantities and types of lignocellulosic residues. Secondly, the possible high added-value chemicals obtained from transformation of lignocellulosic waste are detailed, as well as their potential for applications in the food industry, biomedical, energy or chemistry sectors, including as sources of polyphenols, enzymes, bioplastic precursors or biofuels. In a third part, various available transformation treatments, such as physical treatments with ultrasound or heat, chemical treatments with acids or bases, and biological treatments with enzymes or microorganisms, are presented. The last part discusses the perspectives of the use of lignocellulosic waste and the fact that decreasing the cost of transformation is one of the major issues for improving the use of lignocellulosic biomass in a circular economy and green chemistry approach, since it is currently often more expensive than petroleum-based counterparts.
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Affiliation(s)
- Elisabeth A Cazier
- UCLy (Lyon Catholic University), ESTBB, Lyon, France; UCLy (Lyon Catholic University), UR CONFLUENCE : Sciences et Humanités (EA 1598), Lyon, France; Nantes Université, Oniris, GEPEA, UMR 6144, F-44600 Saint-Nazaire, France(1).
| | - Thanh-Nhat Pham
- UCLy (Lyon Catholic University), ESTBB, Lyon, France; UCLy (Lyon Catholic University), UR CONFLUENCE : Sciences et Humanités (EA 1598), Lyon, France
| | - Louis Cossus
- UCLy (Lyon Catholic University), ESTBB, Lyon, France; UCLy (Lyon Catholic University), UR CONFLUENCE : Sciences et Humanités (EA 1598), Lyon, France
| | - Maher Abla
- UCLy (Lyon Catholic University), ESTBB, Lyon, France; UCLy (Lyon Catholic University), UR CONFLUENCE : Sciences et Humanités (EA 1598), Lyon, France.
| | - Tina Ilc
- UCLy (Lyon Catholic University), ESTBB, Lyon, France; UCLy (Lyon Catholic University), UR CONFLUENCE : Sciences et Humanités (EA 1598), Lyon, France.
| | - Philip Lawrence
- UCLy (Lyon Catholic University), ESTBB, Lyon, France; UCLy (Lyon Catholic University), UR CONFLUENCE : Sciences et Humanités (EA 1598), Lyon, France.
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2
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Jiang X, Zhai R, Li H, Li C, Deng Q, Jin M. Understanding acid hydrolysis of corn stover during densification pretreatment for quantitative predictions of enzymatic hydrolysis efficiency using modified pretreatment severity factor. BIORESOURCE TECHNOLOGY 2023; 386:129487. [PMID: 37454958 DOI: 10.1016/j.biortech.2023.129487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/09/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
DLCA(sa) pretreatment (densifying lignocellulosic biomass with sulfuric acid followed by autoclave treatment), featured with low treatment temperature and densification, demonstrate high efficiency in biomass pretreatment. In this study, the effects of temperature, acid loading, time on the hydrolysis of xylan, cellulose and lignin during DLCA(sa) pretreatment were systematically investigated. It was shown that DLCA(sa) pretreatment can effectively solubilize xylan, achieving an 84% xylose recovery under mild conditions (130 °C, 30 min, and 0.125 g/g acid loading). The conventional pretreatment severity factor correlated and further modified to improve the accuracy in evaluating the xylan hydrolysis. Additionally, a mathematical model based on the xylan hydrolytic kinetics was proposed to predict the enzymatic hydrolysis. Kinetic model suggested that mechanical densification facilitates the penetration of acid into the biomass matrix, leading to increased accessibility of xylan to acid catalysis.
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Affiliation(s)
- Xiaoxiao Jiang
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Rui Zhai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Haixiang Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Chen Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Qiufeng Deng
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China.
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3
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Hu Y, Liu T, Chen N, Feng C, Lu W, Guo H. Simultaneous bio-reduction of nitrate and Cr(VI) by mechanical milling activated corn straw. JOURNAL OF HAZARDOUS MATERIALS 2022; 429:128258. [PMID: 35101762 DOI: 10.1016/j.jhazmat.2022.128258] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
Abundant lignocellulose waste is an ideal energy source for environmental bioremediation, but its recalcitrance to bioavailability makes this a challenging prospect. We hypothesized that the disruption of straw's recalcitrant structure by mechanochemical ball milling would enhance its availability for the simultaneous bioreduction of nitrate and Cr(VI). The results showed that the ball-milling process increased the quantity of water-soluble organic matter released from corn straw and changed the composition of organic matter by strongly disrupting its lignocellulose structure. The increase in ball-milling time increased the specific surface area of the straw and favored the adhesion of microorganisms on the straw surface, which enhanced the bioavailability of the energy in the straw. Substantially increased removal of NO3--N (206.47 ± 0.67 mg/g) and Cr(VI) (37.62 ± 0.09 mg/g) was achieved by using straw that was ball milled for 240 min, which validated that ball milling can improve the utilization efficiency of straw by microorganisms. Cellular and molecular biological analyses showed that ball-milled straw increased microbial energy metabolism and cellular activity related to the electron transport chain. This work offers a potential way to achieve the win-win goal of utilizing agricultural wastes and remediating environmental pollution.
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Affiliation(s)
- Yutian Hu
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, and School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China
| | - Tong Liu
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, and School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China
| | - Nan Chen
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, and School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China.
| | - Chuanping Feng
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, and School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China
| | - Wang Lu
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, and School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China
| | - Huaming Guo
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, and School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, PR China.
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4
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Jiang X, Zhai R, Leng Y, Deng Q, Jin M. Understanding the toxicity of lignin-derived phenolics towards enzymatic saccharification of lignocellulose for rationally developing effective in-situ mitigation strategies to maximize sugar production from lignocellulosic biorefinery. BIORESOURCE TECHNOLOGY 2022; 349:126813. [PMID: 35134522 DOI: 10.1016/j.biortech.2022.126813] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/29/2022] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
The lignin-derived phenolics are highly inhibitory toward lignocellulose enzymatic hydrolysis, while the relationship between phenolic structure and inhibitory effect is still not fully understood. In this study, the compositions of phenolics from dilute acid pretreated wheat straw were analyzed and their impact on cellulose hydrolysis was studied. With increase of pretreatment severity, more toxic phenolics were produced from lignin degradation reactions, which were the major contributor to the increased inhibitory effect of pretreatment hydrolysate towards cellulases. Through analyzing the relationship of phenolic structure and their inhibitory effect, a useful model was developed to predict the phenolics-caused inhibition by combining the indexes of electrophilicity and hydrophobicity. Further, through understanding the interactions between phenolics and cellulases, a novel biocomponent alleviator was rationally designed to block the phenolics-cellulase interactions, the degree of improvement of enzymatic hydrolysis reached as high as 135.8%. This study provides directions for developing more effective pretreatment and detoxification methods.
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Affiliation(s)
- Xiaoxiao Jiang
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Rui Zhai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Yu Leng
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Qiufeng Deng
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China.
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5
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Noppawan P, Lanctôt AG, Magro M, Navarro PG, Supanchaiyamat N, Attard TM, Hunt AJ. High pressure systems as sustainable extraction and pre-treatment technologies for a holistic corn stover biorefinery. BMC Chem 2021; 15:37. [PMID: 34051832 PMCID: PMC8164268 DOI: 10.1186/s13065-021-00762-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/11/2021] [Indexed: 11/10/2022] Open
Abstract
This mini-review assesses supercritical carbon dioxide (scCO2) extraction and high-pressure carbon dioxide pre-treatment technologies for valorisation of corn stover agricultural residues with particular focus on showing how these can aid in the creation of a holistic biorefineries. Corn stover is currently the largest source of agriculture residues in the USA, as such there is significant potential for exploitation to yield valuable chemicals. ScCO2 extraction could lead to the recovery of a variety of different chemicals which include flavonoids, sterols, steroid ketones, hydrocarbons, saturated fatty acids, unsaturated fatty acids, fatty alcohols, phenolics and triterpenoids. Importantly, recent studies have not only demonstrated that supercritical extraction can be utilized for the recovery of plant lipids for use in consumer products, including nutraceuticals and personal care, but the processing of treated biomass can lead to enhanced yields and recovery of other products from biorefinery processes. Despite the great potential and opportunities for using scCO2 and high-pressure systems in a biorefinery context their real-world application faces significant challenges to overcome before it is widely applied. Such challenges have also been discussed in the context of this mini-review.
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Affiliation(s)
- Pakin Noppawan
- Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Adrienne Gallant Lanctôt
- Green Chemistry Centre of Excellence, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Maria Magro
- Green Chemistry Centre of Excellence, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Pablo Gil Navarro
- Green Chemistry Centre of Excellence, Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Nontipa Supanchaiyamat
- Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Thomas M Attard
- RX Extraction Ltd., Unit 10, Rowen Trade Estate, Neville Road, Bradford, BD4 8TQ, UK.
| | - Andrew J Hunt
- Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
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Ji MG, Lee YR, Nam YH, Castañeda R, Hong BN, Kang TH. Immunostimulatory Action of High-Content Active Arabinoxylan in Rice Bran. ACS OMEGA 2020; 5:26374-26381. [PMID: 33110965 PMCID: PMC7581081 DOI: 10.1021/acsomega.0c02472] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Immunostimulatory activity comprises specific and nonspecific immune responses stimulated by internal and external factors. Arabinoxylan is well known for its immunostimulatory activity in vivo and in vitro, although the biological activities of arabinoxylan oligosaccharides depend on their structural features. In this study, we aimed to evaluate in vitro and in vivo the immunostimulatory activity of high-content active arabinoxylan (HCAA) obtained from rice bran through bioconversion by microorganisms and acid hydrolysis. Three microorganisms, Penicillium rocheforti, Aspergillus oryzae, and Pleurotus osteatus, and three different acid concentrations of hydrochloric acid (5, 10, and 20%) and acetic acid (25, 50, and 75%) were used for producing HCAA. HPLC analysis of arabinose and xylose content revealed that fermentation with P. rocheforti followed by hydrolysis with 5% hydrochloric acid was the most efficient to produce HCAA. GPC analysis of HCAA indicates that HCAA is a complex of various forms of saccharides and shows an average molecular weight of 625. Further, in vitro evaluation disclosed that exposure to HCAA (10-200 μg/mL) increased cell viability in mice splenic cells and RAW 264.7 cells. Additionally, exposure of mice to oral administration of HCAA (100 mg/kg) for 4-7 days increased lymphokine-activated killer (LAK)- and macrophage-mediated cytotoxic activity in cancer cells (YAC-1). Furthermore, in vitro exposure to HCAA and oral administrations in mice revealed increased interferon-γ (IFN-γ) and interleukin-10 (IL-10) protein expression through western blot analysis in RAW 264.7 cells and isolated splenic cells. Our results suggest that HCAA developed by bioconversion and acid hydrolysis may enhance immune responses in vivo and in vitro.
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7
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Cha JS, Um BH. Levulinic acid production through two-step acidic and thermal treatment of food waste using dilute hydrochloric acid. KOREAN J CHEM ENG 2020. [DOI: 10.1007/s11814-020-0521-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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8
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Cha JS, Um BH. Delignification of Pinecone and Extraction of Formic Acid in the Hydrolysate Produced by Alkaline Fractionation. Appl Biochem Biotechnol 2020; 192:103-119. [PMID: 32270381 DOI: 10.1007/s12010-020-03311-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 03/12/2020] [Indexed: 11/29/2022]
Abstract
The objectives of our research are to investigate the concept of delignification from pinecone through alkaline fractionation and then extraction of formic acid from the hydrolysate through esterification using ethanol. The pinecone is considered a promising material because of its relatively higher lignin content (35.80%) than other lignocellulosic biomass. The recovery yield of acid insoluble lignin (AIL) reached its maximum value of 79.20% at 8% NaOH, and the concentration of formic acid in the hydrolysate had its highest value under the same conditions. Moreover, the glucan content in fractionated solid remained high. The hydrolysate was subjected to esterification with ethanol under various reaction conditions for formic acid extraction, with solvent mixing ratio range: 1:1-1:4 v/v, reaction temperature range: 30-45 °C, and reaction time range: 60-100 min. Subsequently, the ethanol mixture (ethanol and ethyl formate) was recovered through distillation. The formic acid was extracted with more than 85% at mixing ratio of 1:2 and 45 °C for all reaction times. Furthermore, salt compounds composed mainly of Na and S were recovered because of its properties not soluble in ethanol solution.
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Affiliation(s)
- Jin Seong Cha
- Department of Chemical Engineering and Interagency Convergence Energy on New Biomass Industry, Hankyong National University, 327, Jungang-ro, Anseong-si, Gyeonggi-do, 17579, South Korea
| | - Byung Hwan Um
- Department of Chemical Engineering and Interagency Convergence Energy on New Biomass Industry, Hankyong National University, 327, Jungang-ro, Anseong-si, Gyeonggi-do, 17579, South Korea.
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9
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Study of the Application of Alkaline Extrusion to the Pretreatment of Eucalyptus Biomass as First Step in a Bioethanol Production Process. ENERGIES 2018. [DOI: 10.3390/en11112961] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Eucalyptus biomass was studied as a feedstock for sugars release using an alkaline extrusion plus a neutralization-based pretreatment. This approach would be a first step in a bioconversion process aimed at obtaining fuel bioethanol from eucalyptus biomass. The best operation conditions of extrusion (screw speed, temperature, liquid to solid ratio and NaOH amount) that lead to an effective destructuration of lignocellulose and enhanced sugar release were investigated. Two process configurations, with and without filtration inside the extruder, were tested. In the case without filtration, washed and not washed extrudates were compared. It was demonstrated that filtration step was convenient to remove inorganic salts resulting from neutralization and to promote the mechanical effect of extrusion, but limitations in the machine used in the work prevented testing of temperatures above 100 °C using this configuration. In the no filtration strategy, a temperature of 150 °C allowed attaining the highest glucan and xylan conversion rates by enzymatic hydrolysis of extruded biomass, almost 40% and 75%, respectively, of the maximum yield that could be attained if all carbohydrates contained in raw eucalyptus were converted to sugars. Some of the mechanisms and individual effects underlying alkaline extrusion of eucalyptus were figured out in this work, providing guidelines for a successful pretreatment design that needs to be further studied.
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10
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Perspective and prospective of pretreatment of corn straw for butanol production. Appl Biochem Biotechnol 2014; 172:840-53. [PMID: 24122704 DOI: 10.1007/s12010-013-0548-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 09/19/2013] [Indexed: 10/26/2022]
Abstract
Corn straw, lignocellulosic biomass, is a potential substrate for microbial production of bio-butanol. Bio-butanol is a superior second generation biofuel among its kinds. Present researches are focused on the selection of butanol tolerant clostridium strain(s) to optimize butanol yield in the fermentation broth because of toxicity of bio-butanol to the clostridium strain(s) itself. However, whatever the type of the strain(s) used, pretreatment process always affects not only the total sugar yield before fermentation but also the performance and growth of microbes during fermentation due to the formation of hydroxyl-methyl furfural, furfural and phenolic compounds. In addition, the lignocellulosic biomasses also resist physical and biological attacks. Thus, selection of best pretreatment process and its parameters is crucial. In this context, worldwide research efforts are increased in past 12 years and researchers are tried to identify the best pretreatment method, pretreatment conditions for the actual biomass. In this review, effect of particle size, status of most common pretreatment method and enzymatic hydrolysis particularly for corn straw as a substrate is presented. This paper also highlights crucial parameters necessary to consider during most common pretreatment processes such as hydrothermal, steam explosion, ammonia explosion, sulfuric acid, and sodium hydroxide pretreatment. Moreover, the prospective of pretreatment methods and challenges is discussed.
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11
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Baral NR, Shah A. Microbial inhibitors: formation and effects on acetone-butanol-ethanol fermentation of lignocellulosic biomass. Appl Microbiol Biotechnol 2014; 98:9151-72. [DOI: 10.1007/s00253-014-6106-8] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/15/2014] [Accepted: 09/16/2014] [Indexed: 12/26/2022]
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Rajan K, Carrier DJ. Characterization of Rice Straw Prehydrolyzates and Their Effect on the Hydrolysis of Model Substrates Using a Commercial endo-Cellulase, β-Glucosidase and Cellulase Cocktail. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2014; 2:2124-2130. [PMID: 25243103 PMCID: PMC4165551 DOI: 10.1021/sc5002947] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/30/2014] [Indexed: 05/29/2023]
Abstract
Pretreatment and enzymatic saccharification are two major upstream processes that affect the economic feasibility and sustainability of lignocellulosic biofuel production. Cellulase-inhibiting degradation products, generated during dilute acid pretreatment, increase enzyme usage, and therefore, it is essential to mitigate their production. In an attempt to elucidate the most deleterious degradation product to enzymatic hydrolysis, hydrolyzates were generated from rice straw, and their effect on enzyme activity was determined. Ground rice straw was subjected to the following pretreatments having a combined severity factor of 1.75: T1-160 °C, pH 1.7; T2-180 °C, pH 2.25; and T3-220 °C, pH 7.0. The liquid prehydrolyzates were freeze-dried, and their inhibitory effects on the activities of a commercial cellulase cocktail, endo-cellulase, and β-glucosidase were determined using filter paper, carboxymethyl cellulose, and cellobiose, respectively. Addition of 15 g L-1 of T1, T2, or T3 freeze-dried prehydrolyzates resulted in 67%, 57%, and 77% reduction in CMC-ase activity of endo-cellulase, respectively. In the presence of 35 g L-1 of T1, T2, or T3 prehydrolyzates, the filter paper activity of the cellulase cocktail was reduced by 64%, 68%, and 82%, respectively. Characterization of the freeze-dried prehydrolyzates showed that T3 had significantly higher xylo-oligosaccharides and total phenolic content than T2 and T1.
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Affiliation(s)
- Kalavathy Rajan
- Department
of Food Science, University of Arkansas, 2650 N. Young Ave, Fayetteville, Arkansas 72704, United States
| | - Danielle Julie Carrier
- Department
of Biological and Agricultural Engineering, University of Arkansas, 203 Engineering Hall, Fayetteville, Arkansas 72701, United
States
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13
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Kim IJ, Lee HJ, Choi IG, Kim KH. Synergistic proteins for the enhanced enzymatic hydrolysis of cellulose by cellulase. Appl Microbiol Biotechnol 2014; 98:8469-80. [PMID: 25129610 DOI: 10.1007/s00253-014-6001-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 07/28/2014] [Accepted: 07/29/2014] [Indexed: 01/09/2023]
Abstract
Reducing the enzyme loadings for enzymatic saccharification of lignocellulose is required for economically feasible production of biofuels and biochemicals. One strategy is addition of small amounts of synergistic proteins to cellulase mixtures. Synergistic proteins increase the activity of cellulase without causing significant hydrolysis of cellulose. Synergistic proteins exert their activity by inducing structural modifications in cellulose. Recently, synergistic proteins from various biological sources, including bacteria, fungi, and plants, were identified based on genomic data, and their synergistic activities were investigated. Currently, an up-to-date overview of several aspects of synergistic proteins, such as their functions, action mechanisms and synergistic activity, are important for future industrial application. In this review, we summarize the current state of research on four synergistic proteins: carbohydrate-binding modules, plant expansins, expansin-like proteins, and Auxiliary Activity family 9 (formerly GH61) proteins. This review provides critical information to aid in promoting research on the development of efficient and industrially feasible synergistic proteins.
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Affiliation(s)
- In Jung Kim
- Department of Biotechnology, Korea University Graduate School, Seoul, 136-713, Republic of Korea
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14
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Rana V, Eckard AD, Teller P, Ahring BK. On-site enzymes produced from Trichoderma reesei RUT-C30 and Aspergillus saccharolyticus for hydrolysis of wet exploded corn stover and loblolly pine. BIORESOURCE TECHNOLOGY 2014; 154:282-9. [PMID: 24412480 DOI: 10.1016/j.biortech.2013.12.059] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 12/09/2013] [Accepted: 12/12/2013] [Indexed: 05/02/2023]
Abstract
Cellulase production by two filamentous fungi Trichoderma reesei RUT-C30 and novel fungal strain, Aspergillus saccharolyticus on pretreated corn stover was investigated. Cellulase production was followed by the hydrolysis of two feedstocks, wet-exploded corn stover (WECS) and wet-exploded loblolly pine (WELP) by on-site produced enzyme cocktails containing cellulase from T. reesei RUT-C30 and β-glucosidase from A. saccharolyticus. The sugar yields using the on-site enzyme cocktails were compared with commercial enzymes preparations, Celluclast 1.5L and Novozym 188 at two substrate concentrations, 5% and 10% (w/w) and enzyme loading at 5 and 15 FPU/g glucan for WECS and WELP. The highest sugar yields were obtained at 5% (w/w) substrate concentration and 15 FPU/g glucan for both feedstocks. Glucose yields of 81% and 88% were obtained from on-site and commercial enzymes, respectively using WECS as feed stock. The sugar yields were 55% and 58% for WELP samples hydrolyzed with on-site and commercial enzymes, respectively.
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Affiliation(s)
- Vandana Rana
- Bioproducts, Sciences and Engineering Laboratory (BSEL), Washington State University Richland, WA 99354, United States
| | - Anahita D Eckard
- Bioproducts, Sciences and Engineering Laboratory (BSEL), Washington State University Richland, WA 99354, United States
| | - Philip Teller
- Bioproducts, Sciences and Engineering Laboratory (BSEL), Washington State University Richland, WA 99354, United States
| | - Birgitte K Ahring
- Bioproducts, Sciences and Engineering Laboratory (BSEL), Washington State University Richland, WA 99354, United States.
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15
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Wolfrum EJ, Ness RM, Nagle NJ, Peterson DJ, Scarlata CJ. A laboratory-scale pretreatment and hydrolysis assay for determination of reactivity in cellulosic biomass feedstocks. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:162. [PMID: 24229321 PMCID: PMC4176505 DOI: 10.1186/1754-6834-6-162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 10/28/2013] [Indexed: 05/18/2023]
Abstract
BACKGROUND The rapid determination of the release of structural sugars from biomass feedstocks is an important enabling technology for the development of cellulosic biofuels. An assay that is used to determine sugar release for large numbers of samples must be robust, rapid, and easy to perform, and must use modest amounts of the samples to be tested.In this work we present a laboratory-scale combined pretreatment and saccharification assay that can be used as a biomass feedstock screening tool. The assay uses a commercially available automated solvent extraction system for pretreatment followed by a small-scale enzymatic hydrolysis step. The assay allows multiple samples to be screened simultaneously, and uses only ~3 g of biomass per sample. If the composition of the biomass sample is known, the results of the assay can be expressed as reactivity (fraction of structural carbohydrate present in the biomass sample released as monomeric sugars). RESULTS We first present pretreatment and enzymatic hydrolysis experiments on a set of representative biomass feedstock samples (corn stover, poplar, sorghum, switchgrass) in order to put the assay in context, and then show the results of the assay applied to approximately 150 different feedstock samples covering 5 different materials. From the compositional analysis data we identify a positive correlation between lignin and structural carbohydrates, and from the reactivity data we identify a negative correlation between both carbohydrate and lignin content and total reactivity. The negative correlation between lignin content and total reactivity suggests that lignin may interfere with sugar release, or that more mature samples (with higher structural sugars) may have more recalcitrant lignin. CONCLUSIONS The assay presented in this work provides a robust and straightforward method to measure the sugar release after pretreatment and saccharification that can be used as a biomass feedstock screening tool. We demonstrated the utility of the assay by identifying correlations between feedstock composition and reactivity in a population of 150 samples.
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Affiliation(s)
- Edward J Wolfrum
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Ryan M Ness
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Nicholas J Nagle
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Darren J Peterson
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Christopher J Scarlata
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
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Kont R, Kurašin M, Teugjas H, Väljamäe P. Strong cellulase inhibitors from the hydrothermal pretreatment of wheat straw. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:135. [PMID: 24053778 PMCID: PMC3849272 DOI: 10.1186/1754-6834-6-135] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/13/2013] [Indexed: 05/03/2023]
Abstract
BACKGROUND The use of the enzymatic hydrolysis of lignocellulose with subsequent fermentation to ethanol provides a green alternative for the production of transportation fuels. Because of its recalcitrant nature, the lignocellulosic biomass must be pretreated before enzymatic hydrolysis. However, the pretreatment often results in the formation of compounds that are inhibitory for the enzymes or fermenting organism. Although well recognized, little quantitative information on the inhibition of individual cellulase components by identified inhibitors is available. RESULTS Strong cellulase inhibitors were separated from the liquid fraction of the hydrothermal pretreatment of wheat straw. HPLC and mass-spectroscopy analyses confirmed that the inhibitors were oligosaccharides (inhibitory oligosaccharides, IOS) with a degree of polymerization from 7 to 16. The IOS are composed of a mixture of xylo- (XOS) and gluco-oligosaccharides (GOS). We propose that XOS and GOS are the fragments of the xylan backbone and mixed-linkage β-glucans, respectively. The IOS were approximately 100 times stronger inhibitors for Trichoderma reesei cellobiohydrolases (CBHs) than cellobiose, which is one of the strongest inhibitors of these enzymes reported to date. Inhibition of endoglucanases (EGs) by IOS was weaker than that of CBHs. Most of the tested cellulases and hemicellulases were able to slowly degrade IOS and reduce the inhibitory power of the liquid fraction to some extent. The most efficient single enzyme component here was T. reesei EG TrCel7B. Although reduced by the enzyme treatment, the residual inhibitory power of IOS and the liquid fraction was strong enough to silence the major component of the T. reesei cellulase system, CBH TrCel7A. CONCLUSIONS The cellulase inhibitors described here may be responsible for the poor yields from the enzymatic conversion of the whole slurries from lignocellulose pretreatment under conditions that do not favor complete degradation of hemicellulose. Identification of the inhibitory compounds helps to design better enzyme mixtures for their degradation and to optimize the pretreatment regimes to minimize their formation.
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Affiliation(s)
- Riin Kont
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
| | - Mihhail Kurašin
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
| | - Hele Teugjas
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23b - 202, 51010 Tartu, Estonia
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