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Andrew LJ, Lizundia E, MacLachlan MJ. Designing for Degradation: Transient Devices Enabled by (Nano)Cellulose. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2401560. [PMID: 39221689 DOI: 10.1002/adma.202401560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 08/11/2024] [Indexed: 09/04/2024]
Abstract
Transient technology involves materials and devices that undergo controlled degradation after a reliable operation period. This groundbreaking strategy offers significant advantages over conventional devices based on non-renewable materials by limiting environmental exposure to potentially hazardous components after disposal, and by increasing material circularity. As the most abundant naturally occurring polymer on Earth, cellulose is an attractive material for this purpose. Besides, (nano)celluloses are inherently biodegradable and have competitive mechanical, optical, thermal, and ionic conductivity properties that can be exploited to develop sustainable devices and avoid the end-of-life issues associated with conventional systems. Despite its potential, few efforts have been made to review current advances in cellulose-based transient technology. Therefore, this review catalogs the state-of-the-art developments in transient devices enabled by cellulosic materials. To provide a wide perspective, the various degradation mechanisms involved in cellulosic transient devices are introduced. The advanced capabilities of transient cellulosic systems in sensing, photonics, energy storage, electronics, and biomedicine are also highlighted. Current bottlenecks toward successful implementation are discussed, with material circularity and environmental impact metrics at the center. It is believed that this review will serve as a valuable resource for the proliferation of cellulose-based transient technology and its implementation into fully integrated, circular, and environmentally sustainable devices.
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Affiliation(s)
- Lucas J Andrew
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
| | - Erlantz Lizundia
- Life Cycle Thinking Group, Department of Graphic Design and Engineering Projects, Faculty of Engineering in Bilbao, University of the Basque Country (UPV/EHU), Bilbao, 48013, Spain
- BCMaterials, Basque Center for Materials, Applications, and Nanostructures, UPV/EHU Science Park, Leioa, 48940, Spain
| | - Mark J MacLachlan
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, 2355 East Mall, Vancouver, BC, V6T 1Z4, Canada
- WPI Nano Life Science Institute, Kanazawa University, Kanazawa, 920-1192, Japan
- UBC BioProducts Institute, 2385 East Mall, Vancouver, BC, V6T 1Z4, Canada
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2
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Ramtanon I, Berlioz-Barbier A, Remy S, Renault JH, Masle AL. A combined liquid chromatography - trapped ion mobility - tandem high-resolution mass spectrometry and multivariate analysis approach for the determination of enzymatic reactivity descriptors in biomass hydrolysates. J Chromatogr A 2023; 1706:464277. [PMID: 37573756 DOI: 10.1016/j.chroma.2023.464277] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/17/2023] [Accepted: 08/02/2023] [Indexed: 08/15/2023]
Abstract
Intermediate products such as oxygenated compounds may interfere with bioconversion kinetics of lignocellulosic biomass into bioethanol. This work presents a multidimensional approach, based on liquid chromatography (LC), trapped ion mobility spectrometry (TIMS), tandem high-resolution mass spectrometry (HRMS/MS), and multivariate analysis, for the identification of enzymatic reactivity descriptors in 22 industrial biomass samples, called hydrolysates. The first part of the study is dedicated to the improvement of the chemical diversity assessment of the hydrolysates through an original three-dimensional Van Krevelen diagram displaying the double bond equivalent (DBE) as third dimension. In a second part, the evaluation of data by multivariate data analysis allowed the discrimination of sample according to the biomass type and the level of enzymatic reactivity. In the last part, a potential descriptor of low enzymatic reactivity was selected and used in a case study. An in-depth structural analysis was performed on the feature annotated as carbohydrate derivative. Considering the intricate fragmentation spectrum exhibited by the selected feature, trapped ion mobility was employed to enhance separation prior to the HRMS/MS experiments. This final step improved data interpretation and increased the identification confidence level leading to the characterization of xylotriose, 3,5-dimethoxy-4-hydroxybenzaldehyde and 4-hydroxy-3-methoxy-cinnamaldehyde. This is the first study to present an untargeted multidimensional approach for the identification of enzymatic hydrolysis inhibitors in industrial hydrolysate samples.
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Affiliation(s)
- Ian Ramtanon
- IFP Energies nouvelles, rond-point de l'échangeur de Solaize, BP 3, 69360 Solaize, France
| | | | - Simon Remy
- Université de Reims Champagne-Ardenne, CNRS, ICMR 7312, 51097, Reims, France
| | - Jean-Hugues Renault
- Université de Reims Champagne-Ardenne, CNRS, ICMR 7312, 51097, Reims, France
| | - Agnès Le Masle
- IFP Energies nouvelles, rond-point de l'échangeur de Solaize, BP 3, 69360 Solaize, France.
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Carrillo-Varela I, Vidal C, Vidaurre S, Parra C, Machuca Á, Briones R, Mendonça RT. Alkalization of Kraft Pulps from Pine and Eucalyptus and Its Effect on Enzymatic Saccharification and Viscosity Control of Cellulose. Polymers (Basel) 2022; 14:3127. [PMID: 35956642 PMCID: PMC9370887 DOI: 10.3390/polym14153127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/19/2022] [Accepted: 07/28/2022] [Indexed: 02/04/2023] Open
Abstract
Bleached kraft pulps from eucalyptus and pine were subjected to cold caustic extraction (CCE) with NaOH (5, 10, 17.5, and 35%) for hemicelluloses removal and to increase cellulose accessibility. The effect of these changes was evaluated in enzymatic saccharification with the multicomponent Cellic CTec3 enzyme cocktail, and in viscosity reduction of pulps with the monocomponent Trichoderma reesei endoglucanase (EG). After CCE with 10% NaOH (CCE10) and 17.5% NaOH (CCE17.5), hemicellulose content lower than 1% was achieved in eucalyptus and pine pulps, respectively. At these concentrations, cellulose I started to be converted into cellulose II. NaOH concentrations higher than 17.5% decreased the intrinsic viscosity (from 730 to 420 mL/g in eucalyptus and from 510 to 410 mL/g in pine). Cellulose crystallinity was reduced from 60% to 44% in eucalyptus and from 71% to 44% in pine, as the NaOH concentration increased. Enzymatic multicomponent saccharification showed higher glucose yields in all CCE-treated eucalyptus samples (up to 93%) while only CCE17.5 and CCE35 pine pulps achieved 90% after 40 h of incubation. Untreated bleached pulps of both species presented saccharification yields lower than 70%. When monocomponent EG was used to treat the same pulps, depending on enzyme charge and incubation time, a wide range of intrinsic viscosity reduction was obtained (up to 74%). Results showed that eucalyptus pulps are more accessible and easier to hydrolyze by enzymes than pine pulps and that the conversion of cellulose I to cellulose II hydrate only has the effect of increasing saccharification of CCE pine samples. Viscosity reduction of CCE pulps and EG treated pulps were obtained in a wide range indicating that pulps presented characteristics suitable for cellulose derivatives production.
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Affiliation(s)
- Isabel Carrillo-Varela
- Centro de Investigación de Polímeros Avanzados, CIPA, Concepción 4030000, Chile; (I.C.-V.); (R.B.)
| | - Claudia Vidal
- Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile; (C.V.); (S.V.); (C.P.)
- Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
| | - Sebastián Vidaurre
- Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile; (C.V.); (S.V.); (C.P.)
- Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
| | - Carolina Parra
- Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile; (C.V.); (S.V.); (C.P.)
| | - Ángela Machuca
- Departamento de Ciencias y Tecnología Vegetal, Universidad de Concepción, Los Ángeles 4440000, Chile;
| | - Rodrigo Briones
- Centro de Investigación de Polímeros Avanzados, CIPA, Concepción 4030000, Chile; (I.C.-V.); (R.B.)
| | - Regis Teixeira Mendonça
- Centro de Investigación de Polímeros Avanzados, CIPA, Concepción 4030000, Chile; (I.C.-V.); (R.B.)
- Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile; (C.V.); (S.V.); (C.P.)
- Facultad de Ciencias Forestales, Universidad de Concepción, Concepción 4030000, Chile
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Cosgrove DJ. Building an extensible cell wall. PLANT PHYSIOLOGY 2022; 189:1246-1277. [PMID: 35460252 PMCID: PMC9237729 DOI: 10.1093/plphys/kiac184] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/21/2022] [Indexed: 05/15/2023]
Abstract
This article recounts, from my perspective of four decades in this field, evolving paradigms of primary cell wall structure and the mechanism of surface enlargement of growing cell walls. Updates of the structures, physical interactions, and roles of cellulose, xyloglucan, and pectins are presented. This leads to an example of how a conceptual depiction of wall structure can be translated into an explicit quantitative model based on molecular dynamics methods. Comparison of the model's mechanical behavior with experimental results provides insights into the molecular basis of complex mechanical behaviors of primary cell wall and uncovers the dominant role of cellulose-cellulose interactions in forming a strong yet extensible network.
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Affiliation(s)
- Daniel J Cosgrove
- Department of Biology, Penn State University, Pennsylvania 16802, USA
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Pramanik S, Semenova MV, M Rozhkova A, Zorov IN, Korotkova O, Sinitsyn AP, Davari MD. An engineered cellobiohydrolase I for sustainable degradation of lignocellulosic biomass. Biotechnol Bioeng 2021; 118:4014-4027. [PMID: 34196389 DOI: 10.1002/bit.27877] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/29/2021] [Accepted: 06/20/2021] [Indexed: 11/11/2022]
Abstract
This study provides computational-assisted engineering of the cellobiohydrolase I (CBH-I) from Penicillium verruculosum with simultaneous enhanced thermostability and tolerance in ionic liquids, deep eutectic solvent, and concentrated seawater without affecting its wild-type activity. Engineered triple variant CBH-I R1 (A65R-G415R-S181F) showed 2.48-fold higher thermostability in terms of relative activity at 65°C after 1 h of incubation when compared with CBH-I wild type. CBH-I R1 exhibited 1.87-fold, 1.36-fold, and 1.57-fold higher specific activities compared with CBH-I wild type in [Bmim]Cl (50 g/L), [Ch]Cl (50 g/L), and two-fold concentrated seawater, respectively. In the multicellulases mixture, CBH-I R1 showed higher hydrolytic efficiency to hydrolyze aspen wood compared with CBH-I wild type in the buffer, [Bmim]Cl (50 g/L), and two-fold concentrated seawater, respectively. Structural analysis revealed a molecular basis for the higher stability of the CBH-I structure in which A65R and G415R substitutions form salt bridges (D64 … R65, E411 … R415) and S181F forms π-π interaction (Y155 … F181), leading to stabilize surface-exposed flexible α-helixes and loop in the multidomain β-jelly roll fold structure, respectively. In conclusion, the variant CBH-I R1 could enable efficient lignocellulosic biomass degradation as a cost-effective alternative for the sustainable production of biofuels and value-added chemicals.
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Affiliation(s)
- Subrata Pramanik
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Margarita V Semenova
- Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, Russia
| | - Aleksandra M Rozhkova
- Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, Russia
| | - Ivan N Zorov
- Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, Russia.,Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Olga Korotkova
- Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, Russia
| | - Arkady P Sinitsyn
- Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow, Russia.,Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Mehdi D Davari
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
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6
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From lignocellulose to plastics: Knowledge transfer on the degradation approaches by fungi. Biotechnol Adv 2021; 50:107770. [PMID: 33989704 DOI: 10.1016/j.biotechadv.2021.107770] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/04/2021] [Accepted: 05/08/2021] [Indexed: 01/21/2023]
Abstract
In this review, we argue that there is much to be learned by transferring knowledge from research on lignocellulose degradation to that on plastic. Plastic waste accumulates in the environment to hazardous levels, because it is inherently recalcitrant to biological degradation. Plants evolved lignocellulose to be resistant to degradation, but with time, fungi became capable of utilising it for their nutrition. Examples of how fungal strategies to degrade lignocellulose could be insightful for plastic degradation include how fungi overcome the hydrophobicity of lignin (e.g. production of hydrophobins) and crystallinity of cellulose (e.g. oxidative approaches). In parallel, knowledge of the methods for understanding lignocellulose degradation could be insightful such as advanced microscopy, genomic and post-genomic approaches (e.g. gene expression analysis). The known limitations of biological lignocellulose degradation, such as the necessity for physiochemical pretreatments for biofuel production, can be predictive of potential restrictions of biological plastic degradation. Taking lessons from lignocellulose degradation for plastic degradation is also important for biosafety as engineered plastic-degrading fungi could also have increased plant biomass degrading capabilities. Even though plastics are significantly different from lignocellulose because they lack hydrolysable C-C or C-O bonds and therefore have higher recalcitrance, there are apparent similarities, e.g. both types of compounds are mixtures of hydrophobic polymers with amorphous and crystalline regions, and both require hydrolases and oxidoreductases for their degradation. Thus, many lessons could be learned from fungal lignocellulose degradation.
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7
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Haske-Cornelius O, Hartmann A, Brunner F, Pellis A, Bauer W, Nyanhongo GS, Guebitz GM. Effects of enzymes on the refining of different pulps. J Biotechnol 2020; 320:1-10. [PMID: 32553829 DOI: 10.1016/j.jbiotec.2020.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/29/2020] [Accepted: 06/09/2020] [Indexed: 11/30/2022]
Abstract
Comparative studies of the effects of two commercial enzyme formulations on fiber refining were conducted. Extensive basic characterisation of the enzymes involved, assessment of their hydrolytic activities on different model substrates as well as on different pulps (softwood sulfate, softwood sulfite, hardwood sulfate) were evaluated. Both enzyme formulations showed endoglucanase as well as some xylanase and β-glucosidase activity. In addition, Enzyme A reached a CMC end viscosity of 19.5 mPa compared to 11.1 mPa for Enzyme B. Reducing sugar release almost doubled from 695 μmol mL-1 for hardwood sulfate pulp to 1300 μmol mL-1 for softwood sulfite pulp with Enzyme B under the same conditions. Enzyme A increased the degree of refining even under non-ideal conditions from 23 °SR to up to 50 °SR. Further characterization of hand sheets, made from enzyme pre-treated and refined cellulose fibers with Enzyme A and B, showed that Enzyme A had the best effects leading to hand sheets with increased tensile strength and low air permeability. In summary, the increase in the degree of refining seen for Enzyme A correlated to higher xylanase and β-glucosidase activity and lower endoglucanase activity.
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Affiliation(s)
- Oskar Haske-Cornelius
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 20, 3430, Tulln an der Donau, Austria
| | - Alexandra Hartmann
- Graz University of Technology, Institute of Paper, Pulp and Fiber Technology, Inffeldgasse 23, Graz, 8010, Austria
| | - Florian Brunner
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 20, 3430, Tulln an der Donau, Austria
| | - Alessandro Pellis
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 20, 3430, Tulln an der Donau, Austria
| | - Wolfgang Bauer
- Graz University of Technology, Institute of Paper, Pulp and Fiber Technology, Inffeldgasse 23, Graz, 8010, Austria
| | - Gibson S Nyanhongo
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 20, 3430, Tulln an der Donau, Austria.
| | - Georg M Guebitz
- Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 20, 3430, Tulln an der Donau, Austria; Austrian Centre of Industrial Biotechnology, Konrad-Lorenz-Strasse 20, 3430, Tulln an der Donau, Austria
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8
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Ren M, Wang Y, Liu G, Zuo B, Zhang Y, Wang Y, Liu W, Liu X, Zhong Y. The effects of deletion of cellobiohydrolase genes on carbon source-dependent growth and enzymatic lignocellulose hydrolysis in Trichoderma reesei. J Microbiol 2020; 58:687-695. [PMID: 32524344 DOI: 10.1007/s12275-020-9630-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/22/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
The saprophytic fungus Trichoderma reesei has long been used as a model to study microbial degradation of lignocellulosic biomass. The major cellulolytic enzymes of T. reesei are the cellobiohydrolases CBH1 and CBH2, which constitute more than 70% of total proteins secreted by the fungus. However, their physiological functions and effects on enzymatic hydrolysis of cellulose substrates are not sufficiently elucidated. Here, the cellobiohydrolase-encoding genes cbh1 and cbh2 were deleted, individually or combinatively, by using an auxotrophic marker-recycling technique in T. reesei. When cultured on media with different soluble carbon sources, all three deletion strains (Δcbh1, Δcbh2, and Δcbh1Δcbh2) exhibited no dramatic variation in morphological phenotypes, but their growth rates increased apparently when cultured on soluble cellulase-inducing carbon sources. In addition, Δcbh1 showed dramatically reduced growth and Δcbh1Δcbh2 could hardly grew on microcrystalline cellulose (MCC), whereas all strains grew equally on sodium carboxymethyl cellulose (CMC-Na), suggesting that the influence of the CBHs on growth was carbon source-dependent. Moreover, five representative cellulose substrates were used to analyse the influence of the absence of CBHs on saccharification efficiency. CBH1 deficiency significantly affected the enzymatic hydrolysis rates of various cellulose substrates, where acid pre-treated corn stover (PCS) was influenced the least. CBH2 deficiency reduced the hydrolysis of MCC, PCS, and acid pre-treated and delignified corncob but improved the hydrolysis ability of filter paper. These results demonstrate the specific contributions of CBHs to the hydrolysis of different types of biomass, which could facilitate the development of tailor-made strains with highly efficient hydrolysis enzymes for certain biomass types in the biofuel industry.
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Affiliation(s)
- Meibin Ren
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China
| | - Yifan Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China
| | - Guoxin Liu
- Zibo Center Hospital, Zi Bo, 255036, P. R. China
| | - Bin Zuo
- Leling Shengli New Energy Co., Ltd., Leling, 253600, P. R. China
| | - Yuancheng Zhang
- Leling Shengli New Energy Co., Ltd., Leling, 253600, P. R. China
| | - Yunhe Wang
- Leling Shengli New Energy Co., Ltd., Leling, 253600, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China
| | - Xiangmei Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China.
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, P. R. China.
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Biocatalysis of Industrial Kraft Pulps: Similarities and Differences between Hardwood and Softwood Pulps in Hydrolysis by Enzyme Complex of Penicillium verruculosum. Catalysts 2020. [DOI: 10.3390/catal10050536] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Kraft pulp enzymatic hydrolysis is a promising method of woody biomass bioconversion. The influence of composition and structure of kraft fibers on their hydrolysis efficiency was evaluated while using four substrates, unbleached hardwood pulp (UHP), unbleached softwood pulp (USP), bleached hardwood pulp (BHP), and bleached softwood pulp (BSP). Hydrolysis was carried out with Penicillium verruculosum enzyme complex at a dosage of 10 filter paper units (FPU)/g pulp. The changes in fiber morphology and structure were visualized while using optical and electron microscopy. Fiber cutting and swelling and quick xylan destruction were the main processes at the beginning of hydrolysis. The negative effect of lignin content was more pronounced for USP. Drying decreased the sugar yield of dissolved hydrolysis products for all kraft pulps. Fiber morphology, different xylan and mannan content, and hemicelluloses localization in kraft fibers deeply affected the hydrolyzability of bleached pulps. The introduction of additional xylobiase, mannanase, and cellobiohydrolase activities to enzyme mixture will further improve the hydrolysis of bleached pulps. A high efficiency of never-dried bleached pulp bioconversion was shown. At 10% substrate concentration, hydrolysates with more than 50 g/L sugar concentration were obtained. The bioconversion of never-dried BHP and BSP could be integrated into working kraft pulp mills.
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Yang T, Guo Y, Gao N, Li X, Zhao J. Modification of a cellulase system by engineering Penicillium oxalicum to produce cellulose nanocrystal. Carbohydr Polym 2020; 234:115862. [DOI: 10.1016/j.carbpol.2020.115862] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 12/31/2022]
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11
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Yoo CG, Meng X, Pu Y, Ragauskas AJ. The critical role of lignin in lignocellulosic biomass conversion and recent pretreatment strategies: A comprehensive review. BIORESOURCE TECHNOLOGY 2020; 301:122784. [PMID: 31980318 DOI: 10.1016/j.biortech.2020.122784] [Citation(s) in RCA: 200] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 05/19/2023]
Abstract
Heterogeneity and rigidity of lignocellulose causing resistance to its deconstruction have provided technical and economic challenges in the current biomass conversion processes. Lignin has been considered as a crucial recalcitrance component in biomass utilization. An in-depth understanding of lignin properties and their influences on biomass conversion can provide clues to improve biomass utilization. Also, utilization of lignin can significantly increase the economic viability of biorefinery. Recent lignin-targeting pretreatments have aimed not only to overcome recalcitrance for biomass conversion but also to selectively fractionate lignin for lignin valorization. Numerous studies have been conducted in biomass characteristics and conversion technologies, and the role of lignin is critical for lignin valorization and biomass pretreatment development. This review provides a comprehensive review of lignin-related biomass characteristics, the impact of lignin on the biological conversion of biomass, and recent lignin-targeting pretreatment strategies. The desired lignin properties in biorefinery and future pretreatment directions are also discussed.
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Affiliation(s)
- Chang Geun Yoo
- Department of Paper and Bioprocess Engineering, State University of New York - College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Xianzhi Meng
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996-2200, USA
| | - Yunqiao Pu
- Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA; Center for Bioenergy Innovation (CBI), Joint Institute for Biological Sciences, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA
| | - Arthur J Ragauskas
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996-2200, USA; Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA; Center for Bioenergy Innovation (CBI), Joint Institute for Biological Sciences, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA; Department of Forestry, Wildlife and Fisheries, Center of Renewable Carbon, The University of Tennessee, Institute of Agriculture, Knoxville, TN 37996-2200, USA.
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12
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Lu M, Li J, Han L, Xiao W. An aggregated understanding of cellulase adsorption and hydrolysis for ball-milled cellulose. BIORESOURCE TECHNOLOGY 2019; 273:1-7. [PMID: 30368157 DOI: 10.1016/j.biortech.2018.10.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/13/2018] [Accepted: 10/15/2018] [Indexed: 05/22/2023]
Abstract
This study evaluated the effects of physicochemical properties of a series of ball-milled cellulose on cellulase adsorption and glucose yield. The relationship between cellulase adsorption and initial hydrolysis rate was also discussed. We found that hydrophobicity and surface charge are the key factors affecting cellulase adsorption on ball-milled cellulose. The results demonstrated that glucose yield had a positive correlation with specific surface area, while showed a negative correlation with particle size, degree of polymerization and crystallinity. Among these properties, specific surface area and crystallinity are the key factors affecting glucose yield. As ball milling progressed, cellulose showed lower enzyme adsorption capacity/amount of bound enzyme during initial stage of hydrolysis, but had higher initial hydrolysis rate. The enhanced rate is attributed to the fact that the amorphous region produced by ball milling reduces the free energy required for decrystallization thus increases the catalytic efficiency of the bound enzyme.
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Affiliation(s)
- Minsheng Lu
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Junbao Li
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Lujia Han
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Weihua Xiao
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
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13
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Lambert E, Aguié-Béghin V, Dessaint D, Foulon L, Chabbert B, Paës G, Molinari M. Real Time and Quantitative Imaging of Lignocellulosic Films Hydrolysis by Atomic Force Microscopy Reveals Lignin Recalcitrance at Nanoscale. Biomacromolecules 2018; 20:515-527. [DOI: 10.1021/acs.biomac.8b01539] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Eléonore Lambert
- LRN EA 4682, Université de Reims Champagne-Ardenne, 51685 Reims, France
| | | | - Delphine Dessaint
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, 51100, Reims, France
| | - Laurence Foulon
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, 51100, Reims, France
| | - Brigitte Chabbert
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, 51100, Reims, France
| | - Gabriel Paës
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, 51100, Reims, France
| | - Michaël Molinari
- LRN EA 4682, Université de Reims Champagne-Ardenne, 51685 Reims, France
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15
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Quero F, Padilla C, Campos V, Luengo J, Caballero L, Melo F, Li Q, Eichhorn SJ, Enrione J. Stress transfer and matrix-cohesive fracture mechanism in microfibrillated cellulose-gelatin nanocomposite films. Carbohydr Polym 2018; 195:89-98. [DOI: 10.1016/j.carbpol.2018.04.059] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/22/2018] [Accepted: 04/15/2018] [Indexed: 10/17/2022]
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16
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Sun J, Lu J, Xie G. Secretome analysis of Trichoderma reesei
CICC41495 for degradation of arabinoxylan in malted barley. JOURNAL OF THE INSTITUTE OF BREWING 2018. [DOI: 10.1002/jib.505] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Junyong Sun
- The Key Laboratory of Industrial Biotechnology, Ministry of Education; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
- National Engineering Laboratory for Cereal Fermentation Technology; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
- School of Biotechnology; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
| | - Jian Lu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
- National Engineering Laboratory for Cereal Fermentation Technology; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
- School of Biotechnology; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
| | - Guangfa Xie
- School of Biotechnology; Jiangnan University; 1800 Lihu Road Wuxi 214122 People's Republic of China
- National Engineering Research Center for Chinese Rice Wine; China Shaoxing Rice Wine Group Co. Ltd; Shaoxing 312000 People's Republic of China
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17
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The PT/S-Box of Modular Cellulase AcCel12B Plays a Key Role in the Hydrolysis of Insoluble Cellulose. Catalysts 2018. [DOI: 10.3390/catal8030123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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18
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Spertino S, Boatti L, Icardi S, Manfredi M, Cattaneo C, Marengo E, Cavaletto M. Cellulomonas fimi secretomes: In vivo and in silico approaches for the lignocellulose bioconversion. J Biotechnol 2018; 270:21-29. [PMID: 29409863 DOI: 10.1016/j.jbiotec.2018.01.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/30/2017] [Accepted: 01/26/2018] [Indexed: 12/17/2022]
Abstract
Lignocellulose degradation is a challenging step for value added products and biofuels production. Cellulomonas fimi secretes complex mixtures of carbohydrate active enzymes (CAZymes) which synergistically degrade cellulose and hemicelluloses. Their characterization may provide new insights for enzymatic cocktails implementation. Bioinformatic analysis highlighted 1127 secreted proteins, constituting the in silico secretome, graphically represented in a 2DE map. According to Blast2GO functional annotation, many of these are involved in carbohydrates metabolism. In vivo secretomes were obtained, growing C. fimi on glucose, CMC or wheat straw for 24 h. Zymography revealed degradative activity on carbohydrates and proteomic analysis identified some CAZymes, only in secretomes obtained with CMC and wheat straw. An interaction between cellobiohydrolases is proposed as a strategy adopted by soluble multimodular cellulases. Such approach can be crucial for a better characterization and industrial exploitation of the synergism among C. fimi enzymes.
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Affiliation(s)
- Stefano Spertino
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy.
| | - Lara Boatti
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Sara Icardi
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Marcello Manfredi
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy; ISALIT S.r.l., Novara, Italy
| | - Chiara Cattaneo
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Emilio Marengo
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
| | - Maria Cavaletto
- Department of Scienze e Innovazione Tecnologica, University of Piemonte Orientale, Alessandria, Italy
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19
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Kadowaki MAS, Higasi P, de Godoy MO, Prade RA, Polikarpov I. Biochemical and structural insights into a thermostable cellobiohydrolase from Myceliophthora thermophila. FEBS J 2018; 285:559-579. [PMID: 29222836 DOI: 10.1111/febs.14356] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/20/2017] [Accepted: 12/05/2017] [Indexed: 12/27/2022]
Abstract
Cellobiohydrolases hydrolyze cellulose, a linear polymer with glucose monomers linked exclusively by β-1,4 glycosidic linkages. The widespread hydrogen bonding network tethers individual cellulose polymers forming crystalline cellulose, which prevent the access of hydrolytic enzymes and water molecules. The most abundant enzyme secreted by Myceliophthora thermophila M77 in response to the presence of biomass is the cellobiohydrolase MtCel7A, which is composed by a GH7-catalytic domain (CD), a linker, and a CBM1-type carbohydrate-binding module. GH7 cellobiohydrolases have been studied before, and structural models have been proposed. However, currently available GH7 crystal structures only define separate catalytic domains and/or cellulose-binding modules and do not include the full-length structures that are involved in shaping the catalytic mode of operation. In this study, we determined the 3D structure of catalytic domain using X-ray crystallography and retrieved the full-length enzyme envelope via small-angle X-ray scattering (SAXS) technique. The SAXS data reveal a tadpole-like molecular shape with a rigid linker connecting the CD and CBM. Our biochemical studies show that MtCel7A has higher catalytic efficiency and thermostability as well as lower processivity when compared to the well-studied TrCel7A from Trichoderma reesei. Based on a comparison of the crystallographic structures of CDs and their molecular dynamic simulations, we demonstrate that MtCel7A has considerably higher flexibility than TrCel7A. In particular, loops that cover the active site are more flexible and undergo higher conformational fluctuations, which might account for decreased processivity and enhanced enzymatic efficiency. Our statistical coupling analysis suggests co-evolution of amino acid clusters comprising the catalytic site of MtCel7A, which correlate with the steps in the catalytic cycle of the enzyme. DATABASE The atomic coordinates and structural factors of MtCel7A have been deposited in the Protein Data Bank with accession number 5W11.
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Affiliation(s)
| | - Paula Higasi
- São Carlos Institute of Physics, University of São Paulo, Brazil
| | | | - Rolf A Prade
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Igor Polikarpov
- São Carlos Institute of Physics, University of São Paulo, Brazil
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20
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Song B, Li B, Wang X, Shen W, Park S, Collings C, Feng A, Smith SJ, Walton JD, Ding SY. Real-time imaging reveals that lytic polysaccharide monooxygenase promotes cellulase activity by increasing cellulose accessibility. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:41. [PMID: 29467819 PMCID: PMC5815216 DOI: 10.1186/s13068-018-1023-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/11/2018] [Indexed: 05/08/2023]
Abstract
BACKGROUND The high cost of enzymes is one of the key technical barriers that must be overcome to realize the economical production of biofuels and biomaterials from biomass. Supplementation of enzyme cocktails with lytic polysaccharide monooxygenase (LPMO) can increase the efficiency of these cellulase mixtures for biomass conversion. The previous studies have revealed that LPMOs cleave polysaccharide chains by oxidization of the C1 and/or C4 carbons of the monomeric units. However, how LPMOs enhance enzymatic degradation of lignocellulose is still poorly understood. RESULTS In this study, we combined enzymatic assays and real-time imaging using atomic force microscopy (AFM) to study the molecular interactions of an LPMO [TrAA9A, formerly known as TrCel61A) from Trichoderma reesei] and a cellobiohydrolase I (TlCel7A from T. longibrachiatum) with bacterial microcrystalline cellulose (BMCC) as a substrate. Cellulose conversion by TlCel7A alone was enhanced from 46 to 54% by the addition of TrAA9A. Conversion by a mixture of TlCel7A, endoglucanase, and β-glucosidase was increased from 79 to 87% using pretreated BMCC with TrAA9A for 72 h. AFM imaging demonstrated that individual TrAA9A molecules exhibited intermittent random movement along, across, and penetrating into the ribbon-like microfibril structure of BMCC, which was concomitant with the release of a small amount of oxidized sugars and the splitting of large cellulose ribbons into fibrils with smaller diameters. The dividing effect of the cellulose microfibril occurred more rapidly when TrAA9A and TlCel7A were added together compared to TrAA9A alone; TlCel7A alone caused no separation. CONCLUSIONS TrAA9A increases the accessible surface area of BMCC by separating large cellulose ribbons, and thereby enhances cellulose hydrolysis yield. By providing the first direct observation of LPMO action on a cellulosic substrate, this study sheds new light on the mechanisms by which LPMO enhances biomass conversion.
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Affiliation(s)
- Bo Song
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Bingyao Li
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Xiaoyan Wang
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Wei Shen
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Sungjin Park
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Cynthia Collings
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Anran Feng
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
| | - Steve J. Smith
- Nanoscience and Nanoengineering Program, South Dakota School of Mines and Technology, Rapid City, SD 57701 USA
| | - Jonathan D. Walton
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
| | - Shi-You Ding
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 USA
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21
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Zeng Y, Himmel ME, Ding SY. Visualizing chemical functionality in plant cell walls. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:263. [PMID: 29213316 PMCID: PMC5708085 DOI: 10.1186/s13068-017-0953-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/02/2017] [Indexed: 05/07/2023]
Abstract
Understanding plant cell wall cross-linking chemistry and polymeric architecture is key to the efficient utilization of biomass in all prospects from rational genetic modification to downstream chemical and biological conversion to produce fuels and value chemicals. In fact, the bulk properties of cell wall recalcitrance are collectively determined by its chemical features over a wide range of length scales from tissue, cellular to polymeric architectures. Microscopic visualization of cell walls from the nanometer to the micrometer scale offers an in situ approach to study their chemical functionality considering its spatial and chemical complexity, particularly the capabilities of characterizing biomass non-destructively and in real-time during conversion processes. Microscopic characterization has revealed heterogeneity in the distribution of chemical features, which would otherwise be hidden in bulk analysis. Key microscopic features include cell wall type, wall layering, and wall composition-especially cellulose and lignin distributions. Microscopic tools, such as atomic force microscopy, stimulated Raman scattering microscopy, and fluorescence microscopy, have been applied to investigations of cell wall structure and chemistry from the native wall to wall treated by thermal chemical pretreatment and enzymatic hydrolysis. While advancing our current understanding of plant cell wall recalcitrance and deconstruction, microscopic tools with improved spatial resolution will steadily enhance our fundamental understanding of cell wall function.
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Affiliation(s)
- Yining Zeng
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
| | - Shi-You Ding
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
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22
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Videcoq P, Barbacci A, Assor C, Magnenet V, Arnould O, Le Gall S, Lahaye M. Examining the contribution of cell wall polysaccharides to the mechanical properties of apple parenchyma tissue using exogenous enzymes. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5137-5146. [PMID: 29036637 PMCID: PMC5853499 DOI: 10.1093/jxb/erx329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The viscoelastic mechanical properties of water-rich plant tissues are fundamental for many aspects of organ physiology and plant functioning. These properties are determined partly by the water in cellular vacuole and partly by the mechanical properties of the cell wall, the latter varying according to the composition and organization of its polysaccharides. In this study, relationships between the viscoelastic properties of apple cortex parenchyma tissue and cell wall pectin, hemicelluloses, and cellulose structures were studied by infusing the tissue with selected sets of purified enzymes in a controlled osmoticum. The results showed that tissue elasticity and viscosity were related, and controlled to variable extents by all the targeted polysaccharides. Among them, pectic homogalacturonan domains, crystalline cellulose, and fucosylated xyloglucan were revealed as being of prime importance in determining the viscoelastic mechanical properties of apple cortex tissue.
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Affiliation(s)
- Pauline Videcoq
- INRA, UR1268 Biopolymères Interactions et Assemblages, Nantes, France
| | - Adelin Barbacci
- INRA, UR1268 Biopolymères Interactions et Assemblages, Nantes, France
- Correspondence: or
| | - Carole Assor
- INRA, UR1268 Biopolymères Interactions et Assemblages, Nantes, France
- Université de Montpellier, LMGC, CNRS, Montpellier, France
| | - Vincent Magnenet
- Université de Strasbourg, UMR 7357 Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), CNRS, Illkirch, France
| | | | - Sophie Le Gall
- INRA, UR1268 Biopolymères Interactions et Assemblages, Nantes, France
| | - Marc Lahaye
- INRA, UR1268 Biopolymères Interactions et Assemblages, Nantes, France
- Correspondence: or
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23
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24
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Notable fibrolytic enzyme production by Aspergillus spp. isolates from the gastrointestinal tract of beef cattle fed in lignified pastures. PLoS One 2017; 12:e0183628. [PMID: 28850605 PMCID: PMC5574564 DOI: 10.1371/journal.pone.0183628] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 08/08/2017] [Indexed: 11/25/2022] Open
Abstract
Fungi have the ability to degrade vegetal cell wall carbohydrates, and their presence in the digestive tract of ruminants can minimize the effects of lignified forage on ruminal fermentation. Here, we evaluated enzyme production by Aspergillus spp. isolates from the digestive tracts of cattle grazed in tropical pastures during the dry season. Filamentous fungi were isolated from rumen and feces by culture in cellulose-based medium. Ninety fungal strains were isolated and identified by rDNA sequence analysis, microculture, or both. Aspergillus terreus was the most frequently isolated species, followed by Aspergillus fumigatus. The isolates were characterized with respect to their cellulolytic, xylanolytic, and lignolytic activity through qualitative evaluation in culture medium containing a specific corresponding carbon source. Carboxymethyl cellulase (CMCase) activity was quantified by the reducing sugar method. In the avicel and xilan degradation test, the enzyme activity (EA) at 48 h was significantly higher other periods (P < 0.05). Intra- and inter-specific differences in EA were verified, and high levels of phenoloxidases, which are crucial for lignin degradation, were observed in 28.9% of the isolates. Aspergillus terreus showed significantly higher EA for avicelase (3.96 ±1.77) and xylanase (3.13 ±.091) than the other Aspergillus species at 48 h of incubation. Isolates AT13 and AF69 showed the highest CMCase specific activity (54.84 and 33.03 U mg-1 protein, respectively). Selected Aspergillus spp. isolates produced remarkable levels of enzymes involved in vegetal cell wall degradation, suggesting their potential as antimicrobial additives or probiotics in ruminant diets.
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25
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Singh MK, Kumar M, Thakur IS. Proteomic characterization and schizophyllan production by Schizophyllum commune ISTL04 cultured on Leucaena leucocephala wood under submerged fermentation. BIORESOURCE TECHNOLOGY 2017; 236:29-36. [PMID: 28390274 DOI: 10.1016/j.biortech.2017.03.170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/26/2017] [Accepted: 03/27/2017] [Indexed: 05/07/2023]
Abstract
In this study Schizophyllum commune ISTL04 was grown on Leucaena leucocephala wood (LLW) for secretome analysis and schizophyllan production. There is no report on extracellular protein profile and schizophyllan production on woody biomass by this fungus under submerged fermentation conditions. Leucaena leucocephala, a promising bioenergy crop having high holocellulose content was used as substrate without pretreatment. The maximum sugar, extracellular protein and exopolysaccharide (EPS) production during fermentation was found to be 8.53±0.07mgmL-1, 391±7.51mgL-1 and 4.2±0.1gL-1 or 0.21gg-1LLW on day 18 respectively. The secretome profile was dominated by glycoside hydrolases followed by carbohydrate esterase and other oxidative enzymes. EPS was further characterized by FTIR and GC-MS for functional group, monomer composition and linkage analysis and was identified as schizophyllan. The result indicated that LLW can be utilized as a low cost substrate for enzyme cocktail and schizophyllan production.
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Affiliation(s)
- Manoj Kumar Singh
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Madan Kumar
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Indu Shekhar Thakur
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
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26
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Badino SF, Christensen SJ, Kari J, Windahl MS, Hvidt S, Borch K, Westh P. Exo-exo synergy between Cel6A and Cel7A fromHypocrea jecorina: Role of carbohydrate binding module and the endo-lytic character of the enzymes. Biotechnol Bioeng 2017; 114:1639-1647. [DOI: 10.1002/bit.26276] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/17/2017] [Accepted: 02/21/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Silke F. Badino
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | - Stefan J. Christensen
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | - Jeppe Kari
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | - Michael S. Windahl
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
- Novozymes A/S; Bagsvaerd Denmark
| | - Søren Hvidt
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | | | - Peter Westh
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
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27
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Pereira CS, Silveira RL, Dupree P, Skaf MS. Effects of Xylan Side-Chain Substitutions on Xylan–Cellulose Interactions and Implications for Thermal Pretreatment of Cellulosic Biomass. Biomacromolecules 2017; 18:1311-1321. [DOI: 10.1021/acs.biomac.7b00067] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Caroline S. Pereira
- Institute
of Chemistry, University of Campinas, Campinas, Sao Paulo 13084-862, Brazil
| | - Rodrigo L. Silveira
- Institute
of Chemistry, University of Campinas, Campinas, Sao Paulo 13084-862, Brazil
| | - Paul Dupree
- Department
of Biochemistry and the Leverhulme Natural Material Innovation Centre, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Munir S. Skaf
- Institute
of Chemistry, University of Campinas, Campinas, Sao Paulo 13084-862, Brazil
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28
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Li M, Cao S, Meng X, Studer M, Wyman CE, Ragauskas AJ, Pu Y. The effect of liquid hot water pretreatment on the chemical-structural alteration and the reduced recalcitrance in poplar. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:237. [PMID: 29213308 PMCID: PMC5707831 DOI: 10.1186/s13068-017-0926-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 10/06/2017] [Indexed: 05/12/2023]
Abstract
BACKGROUND Hydrothermal pretreatment using liquid hot water (LHW) is capable of substantially reducing the cell wall recalcitrance of lignocellulosic biomass. It enhances the saccharification of polysaccharides, particularly cellulose, into glucose with relatively low capital required. Due to the close association with biomass recalcitrance, the structural change of the components of lignocellulosic materials during the pretreatment is crucial to understand pretreatment chemistry and advance the bio-economy. Although the LHW pretreatment has been extensively applied and studied, the molecular structural alteration during pretreatment and its significance to reduced recalcitrance have not been well understood. RESULTS We investigated the effects of LHW pretreatment with different severity factors (log R0) on the structural changes of fast-grown poplar (Populus trichocarpa). With the severity factor ranging from 3.6 to 4.2, LHW pretreatment resulted in a substantial xylan solubilization by 50-77% (w/w, dry matter). The molecular weights of the remained hemicellulose in pretreated solids also have been significantly reduced by 63-75% corresponding to LHW severity factor from 3.6 to 4.2. In addition, LHW had a considerable impact on the cellulose structure. The cellulose crystallinity increased 6-9%, whereas its degree of polymerization decreased 35-65% after pretreatment. We found that the pretreatment severity had an empirical linear correlation with the xylan solubilization (R2 = 0.98, r = + 0.99), hemicellulose molecular weight reduction (R2 = 0.97, r = - 0.96 and R2 = 0.93, r = - 0.98 for number-average and weight-average degree of polymerization, respectively), and cellulose crystallinity index increase (R2 = 0.98, r = + 0.99). The LHW pretreatment also resulted in small changes in lignin structure such as decrease of β-O-4' ether linkages and removal of cinnamyl alcohol end group and acetyl group, while the S/G ratio of lignin in LHW pretreated poplar residue remained no significant change compared with the untreated poplar. CONCLUSIONS This study revealed that the solubilization of xylan, the reduction of hemicellulose molecular weights and cellulose degree of polymerization, and the cleavage of alkyl-aryl ether bonds in lignin resulted from LHW pretreatment are critical factors associated with reduced cell wall recalcitrance. The chemical-structural changes of the three major components, cellulose, lignin, and hemicellulose, during LHW pretreatment provide useful and fundamental information of factors governing feedstock recalcitrance during hydrothermal pretreatment.
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Affiliation(s)
- Mi Li
- BioEnergy Science Center (BESC), Oak Ridge, USA
- Biosciences Division, ORNL, Oak Ridge, TN USA
| | - Shilin Cao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA USA
- Present Address: College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou, People’s Republic of China
| | - Xianzhi Meng
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN USA
| | - Michael Studer
- BioEnergy Science Center (BESC), Oak Ridge, USA
- College of Engineering - Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, CA USA
- Present Address: Laboratory for Bioenergy and Biochemicals, School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Bern, Switzerland
| | - Charles E. Wyman
- BioEnergy Science Center (BESC), Oak Ridge, USA
- College of Engineering - Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, CA USA
| | - Arthur J. Ragauskas
- BioEnergy Science Center (BESC), Oak Ridge, USA
- Biosciences Division, ORNL, Oak Ridge, TN USA
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN USA
- Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, University of Tennessee Institute of Agriculture, Knoxville, TN USA
| | - Yunqiao Pu
- BioEnergy Science Center (BESC), Oak Ridge, USA
- Biosciences Division, ORNL, Oak Ridge, TN USA
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29
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Kamat RK, Zhang Y, Anuganti M, Ma W, Noshadi I, Fu H, Ekatan S, Parnas R, Wang C, Kumar CV, Lin Y. Enzymatic Activities of Polycatalytic Complexes with Nonprocessive Cellulases Immobilized on the Surface of Magnetic Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11573-11579. [PMID: 27797206 DOI: 10.1021/acs.langmuir.6b02573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Polycatalytic enzyme complexes made by immobilization of industrial enzymes on polymer- or nanoparticle-based scaffolds are technologically attractive due to their recyclability and their improved substrate binding and catalytic activities. Herein, we report the synthesis of polycatalytic complexes by the immobilization of nonprocessive cellulases on the surface of colloidal polymers with a magnetic nanoparticle core and the study of their binding and catalytic activities. These polycatalytic cellulase complexes have increased binding affinity for the substrate. But due to their larger size, these complexes were unable to access to the internal surfaces of cellulose and have significantly lower binding capacity when compared to those of the corresponding free enzymes. Analysis of released soluble sugars indicated that the formation of complexes may promote the prospect of having consistent, multiple attacks on cellulose substrate. Once bound to the substrate, polycatalytic complexes tend to remain on the surface with very limited mobility due to their strong, multivalent binding to cellulose. Hence, the overall performance of polycatalytic complexes is limited by its substrate accessibility as well as mobility on the substrate surface.
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Affiliation(s)
| | - Yuting Zhang
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University , Shanghai 200433, China
| | | | - Wanfu Ma
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University , Shanghai 200433, China
| | | | | | | | | | - Changchun Wang
- State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University , Shanghai 200433, China
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Crystal structures of wild‐type
Trichoderma reesei
Cel7A catalytic domain in open and closed states. FEBS Lett 2016; 590:4429-4438. [DOI: 10.1002/1873-3468.12464] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/03/2016] [Accepted: 10/10/2016] [Indexed: 11/07/2022]
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Nakamura A, Tasaki T, Ishiwata D, Yamamoto M, Okuni Y, Visootsat A, Maximilien M, Noji H, Uchiyama T, Samejima M, Igarashi K, Iino R. Single-molecule Imaging Analysis of Binding, Processive Movement, and Dissociation of Cellobiohydrolase Trichoderma reesei Cel6A and Its Domains on Crystalline Cellulose. J Biol Chem 2016; 291:22404-22413. [PMID: 27609516 DOI: 10.1074/jbc.m116.752048] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 08/24/2016] [Indexed: 11/06/2022] Open
Abstract
Trichoderma reesei Cel6A (TrCel6A) is a cellobiohydrolase that hydrolyzes crystalline cellulose into cellobiose. Here we directly observed the reaction cycle (binding, surface movement, and dissociation) of single-molecule intact TrCel6A, isolated catalytic domain (CD), cellulose-binding module (CBM), and CBM and linker (CBM-linker) on crystalline cellulose Iα The CBM-linker showed a binding rate constant almost half that of intact TrCel6A, whereas those of the CD and CBM were only one-tenth of intact TrCel6A. These results indicate that the glycosylated linker region largely contributes to initial binding on crystalline cellulose. After binding, all samples showed slow and fast dissociations, likely caused by the two different bound states due to the heterogeneity of cellulose surface. The CBM showed much higher specificity to the high affinity site than to the low affinity site, whereas the CD did not, suggesting that the CBM leads the CD to the hydrophobic surface of crystalline cellulose. On the cellulose surface, intact molecules showed slow processive movements (8.8 ± 5.5 nm/s) and fast diffusional movements (30-40 nm/s), whereas the CBM-Linker, CD, and a catalytically inactive full-length mutant showed only fast diffusional movements. These results suggest that both direct binding and surface diffusion contribute to searching of the hydrolysable point of cellulose chains. The duration time constant for the processive movement was 7.7 s, and processivity was estimated as 68 ± 42. Our results reveal the role of each domain in the elementary steps of the reaction cycle and provide the first direct evidence of the processive movement of TrCel6A on crystalline cellulose.
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Affiliation(s)
- Akihiko Nakamura
- From the Okazaki Institute for Integrative Bioscience and.,the Department of Functional Molecular Science, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Kanagawa 240-0193, Japan
| | - Tomoyuki Tasaki
- the Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Daiki Ishiwata
- From the Okazaki Institute for Integrative Bioscience and
| | | | - Yasuko Okuni
- From the Okazaki Institute for Integrative Bioscience and
| | - Akasit Visootsat
- the Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Morice Maximilien
- the National Chemical Engineering Institute in Paris, Paris 75005, France
| | - Hiroyuki Noji
- the Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Taku Uchiyama
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan, and
| | - Masahiro Samejima
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan, and
| | - Kiyohiko Igarashi
- the Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan, and.,the VTT Technical Research Centre of Finland, Espoo FI-02044 VTT, Finland
| | - Ryota Iino
- From the Okazaki Institute for Integrative Bioscience and .,the Department of Functional Molecular Science, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Kanagawa 240-0193, Japan.,Institute for Molecular Science, National Institutes of Natural Sciences, Aichi 444-8787, Japan
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Tegl G, Öhlknecht C, Vielnascher R, Rollett A, Hofinger-Horvath A, Kosma P, Guebitz GM. Cellobiohydrolases Produce Different Oligosaccharides from Chitosan. Biomacromolecules 2016; 17:2284-92. [DOI: 10.1021/acs.biomac.6b00547] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gregor Tegl
- Institute
of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Straße 20, 3430 Tulln an der Donau, Austria
| | - Christoph Öhlknecht
- Institute
of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Straße 20, 3430 Tulln an der Donau, Austria
| | - Robert Vielnascher
- Institute
of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Straße 20, 3430 Tulln an der Donau, Austria
| | - Alexandra Rollett
- Institute
of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Straße 20, 3430 Tulln an der Donau, Austria
| | - Andreas Hofinger-Horvath
- Department
of Chemistry, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Wien, Austria
| | - Paul Kosma
- Department
of Chemistry, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Wien, Austria
| | - Georg M. Guebitz
- Institute
of Environmental Biotechnology, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Straße 20, 3430 Tulln an der Donau, Austria
- ACIB − Austrian Centre of Industrial Biotechnology, Konrad Lorenz Straße 20, 3430 Tulln, Austria
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Arslan B, Colpan M, Ju X, Zhang X, Kostyukova A, Abu-Lail NI. The Effects of Noncellulosic Compounds on the Nanoscale Interaction Forces Measured between Carbohydrate-Binding Module and Lignocellulosic Biomass. Biomacromolecules 2016; 17:1705-15. [PMID: 27065303 DOI: 10.1021/acs.biomac.6b00129] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The lack of fundamental understanding of the types of forces that govern how cellulose-degrading enzymes interact with cellulosic and noncellulosic components of lignocellulosic surfaces limits the design of new strategies for efficient conversion of biomass to bioethanol. In a step to improve our fundamental understanding of such interactions, nanoscale forces acting between a model cellulase-a carbohydrate-binding module (CBM) of cellobiohydrolase I (CBH I)-and a set of lignocellulosic substrates with controlled composition were measured using atomic force microscopy (AFM). The three model substrates investigated were kraft (KP), sulfite (SP), and organosolv (OPP) pulped substrates. These substrates varied in their surface lignin coverage, lignin type, and xylan and acetone extractives' content. Our results indicated that the overall adhesion forces of biomass to CBM increased linearly with surface lignin coverage with kraft lignin showing the highest forces among lignin types investigated. When the overall adhesion forces were decoupled into specific and nonspecific component forces via the Poisson statistical model, hydrophobic and Lifshitz-van der Waals (LW) forces dominated the binding forces of CBM to kraft lignin, whereas permanent dipole-dipole interactions and electrostatic forces facilitated the interactions of lignosulfonates to CBM. Xylan and acetone extractives' content increased the attractive forces between CBM and lignin-free substrates, most likely through hydrogen bonding forces. When the substrates treated differently were compared, it was found that both the differences in specific and nonspecific forces between lignin-containing and lignin-free substrates were the least for OPP. Therefore, cellulase enzymes represented by CBM would weakly bind to organosolv lignin. This will facilitate an easy enzyme recovery compared to other substrates treated with kraft or sulfite pulping. Our results also suggest that altering the surface hydrophobicity and the surface energy of lignin that facilitates the LW forces should be a priori to avoid nonproductive binding of cellulase to kraft lignin.
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Affiliation(s)
- Baran Arslan
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University , Pullman, Washington 99164-6515, United States
| | - Mert Colpan
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University , Pullman, Washington 99164-6515, United States
| | - Xiaohui Ju
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Bioproducts' Science and Engineering Laboratory, Washington State University , Richland, Washington 99354-1670, United States
| | - Xiao Zhang
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Bioproducts' Science and Engineering Laboratory, Washington State University , Richland, Washington 99354-1670, United States
| | - Alla Kostyukova
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University , Pullman, Washington 99164-6515, United States
| | - Nehal I Abu-Lail
- Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University , Pullman, Washington 99164-6515, United States
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Zhang Y, Zhang M, Alexander Reese R, Zhang H, Xu B. Real-time single molecular study of a pretreated cellulose hydrolysis mode and individual enzyme movement. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:85. [PMID: 27073415 PMCID: PMC4828794 DOI: 10.1186/s13068-016-0498-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 03/31/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND The main challenges of large-scale biochemical conversion involve the high costs of cellulolytic enzymes and the inefficiency in enzymatic deconstruction of polysaccharides embedded in the complex structure of the plant cell wall, leading to ongoing interests in studying the predominant mode of enzymatic hydrolysis. In this study, complete enzymatic hydrolysis of pretreated biomass substrates was visualized in situ and in real time by atomic force microscopy (AFM) topography and recognition imaging. Throughout the entire hydrolytic process, a hydrolysis mode for exoglucanase (CBH I) consisting of a peeling action, wherein cellulose microfibrils are peeled from sites on the pretreated cellulose substrate that have cracks sufficiently large for CBH I to immobilize. RESULTS We quantitatively monitored the complete hydrolytic process on pretreated cellulose. The synergetic effect among the different enzymes can accelerate the cellulose hydrolysis rate dramatically. However, the combination of CBH I and β-glucosidases (β-G) exhibited a similar degradation capacity as did whole enzyme (contains the cellobiohydrolases and endoglucanase as its major enzyme components). We developed a comprehensive dynamic analysis for individual cellulase acting on single pretreated cellulose through use of functional AFM topography and recognition imaging. The single crystalline cellulose was divided into different regions based on the cracks on the substrate surface and was observed to either depolymerize or to peel away by the jammed enzyme molecules. After the exfoliation of one region, new cracks were produced for the enzyme molecules to immobilize. The fiber width may have a relationship with the peeling mode of the fibers. We performed a statistical height measure of the generated peaks of the peeled fibers. The height values range from 11 to 24 nm. We assume that the CBH I enzymes stop progressing along the cellulose microfibril when the peeled microfibril height exceeds 11 nm. CONCLUSION The combination of CBH I and β-G can achieve an effective hydrolysis of the pretreated biomass substrates. The single-molecule study of the complete hydrolytic process indicates that the hydrolytic mode involves the peeling of the microfibrils and progressive depolymerization, which depend on the size of the cracks on the surface of the pretreated cellulose microfibrils.
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Affiliation(s)
- Yanan Zhang
- />Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 USA
- />College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 People’s Republic of China
| | - Mengmeng Zhang
- />Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 USA
| | - R. Alexander Reese
- />Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 USA
| | - Haiqian Zhang
- />College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 People’s Republic of China
| | - Bingqian Xu
- />Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, GA 30602 USA
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Pihlajaniemi V, Sipponen MH, Kallioinen A, Nyyssölä A, Laakso S. Rate-constraining changes in surface properties, porosity and hydrolysis kinetics of lignocellulose in the course of enzymatic saccharification. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:18. [PMID: 26816528 PMCID: PMC4727270 DOI: 10.1186/s13068-016-0431-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/07/2016] [Indexed: 05/27/2023]
Abstract
BACKGROUND Explaining the reduction of hydrolysis rate during lignocellulose hydrolysis is a challenge for the understanding and modelling of the process. This article reports the changes of cellulose and lignin surface areas, porosity and the residual cellulase activity during the hydrolysis of autohydrolysed wheat straw and delignified wheat straw. The potential rate-constraining mechanisms are assessed with a simplified kinetic model and compared to the observed effects, residual cellulase activity and product inhibition. RESULTS The reaction rate depended exclusively on the degree of hydrolysis, while enzyme denaturation or time-dependent changes in substrate hydrolysability were absent. Cellulose surface area decreased linearly with hydrolysis, in correlation with total cellulose content. Lignin surface area was initially decreased by the dissolution of phenolics and then remained unchanged. The dissolved phenolics did not contribute to product inhibition. The porosity of delignified straw was decreased during hydrolysis, but no difference in porosity was detected during the hydrolysis of autohydrolysed straw. CONCLUSIONS Although a hydrolysis-dependent increase of non-productive binding capacity of lignin was not apparent, the dependence of hydrolysis maxima on the enzyme dosage was best explained by partial irreversible product inhibition. Cellulose surface area correlated with the total cellulose content, which is thus an appropriate approximation of the substrate concentration for kinetic modelling. Kinetic models of cellulose hydrolysis should be simplified enough to include reversible and irreversible product inhibition and reduction of hydrolysability, as well as their possible non-linear relations to hydrolysis degree, without overparameterization of particular factors.
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Affiliation(s)
- Ville Pihlajaniemi
- Aalto University, School of Chemical Technology, P.O. Box 16100, FI-00076 Espoo, Finland
| | - Mika Henrikki Sipponen
- Aalto University, School of Chemical Technology, P.O. Box 16100, FI-00076 Espoo, Finland
| | - Anne Kallioinen
- Aalto University, School of Chemical Technology, P.O. Box 16100, FI-00076 Espoo, Finland
| | - Antti Nyyssölä
- Aalto University, School of Chemical Technology, P.O. Box 16100, FI-00076 Espoo, Finland
| | - Simo Laakso
- Aalto University, School of Chemical Technology, P.O. Box 16100, FI-00076 Espoo, Finland
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dos Reis TF, de Lima PBA, Parachin NS, Mingossi FB, de Castro Oliveira JV, Ries LNA, Goldman GH. Identification and characterization of putative xylose and cellobiose transporters in Aspergillus nidulans. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:204. [PMID: 27708711 PMCID: PMC5037631 DOI: 10.1186/s13068-016-0611-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 09/06/2016] [Indexed: 05/07/2023]
Abstract
BACKGROUND The conversion of lignocellulosic biomass to biofuels (second-generation biofuel production) is an environmentally friendlier alternative to petroleum-based energy sources. Enzymatic deconstruction of lignocellulose, catalyzed by filamentous fungi such as Aspergillus nidulans, releases a mixture of mono- and polysaccharides, including hexose (glucose) and pentose (xylose) sugars, cellodextrins (cellobiose), and xylooligosaccharides (xylobiose). These sugars can subsequently be fermented by yeast cells to ethanol. One of the major drawbacks in this process lies in the inability of yeast, such as Saccharomyces cerevisiae, to successfully internalize sugars other than glucose. The aim of this study was, therefore, to screen the genome of A. nidulans, which encodes a multitude of sugar transporters, for transporters able to internalize non-glucose sugars and characterize them when introduced into S. cerevisiae. RESULTS This work identified two proteins in A. nidulans, CltA and CltB, with roles in cellobiose transport and cellulose signaling, respectively. CltA, when introduced into S. cerevisiae, conferred growth on low and high concentrations of cellobiose. Deletion of cltB resulted in reduced growth and extracellular cellulase activity in A. nidulans in the presence of cellobiose. CltB, when introduced into S. cerevisiae, was not able to confer growth on cellobiose, suggesting that this protein is a sensor rather than a transporter. However, we have shown that the introduction of additional functional copies of CltB increases the growth in the presence of low concentrations of cellobiose, strongly indicating CltB is able to transport cellobiose. Furthermore, a previously identified glucose transporter, HxtB, was also found to be a major xylose transporter in A. nidulans. In S. cerevisiae, HxtB conferred growth on xylose which was accompanied by ethanol production. CONCLUSIONS This work identified a cellobiose transporter, a xylose transporter, and a putative cellulose transceptor in A. nidulans. This is the first time that a sensor role for a protein in A. nidulans has been proposed. Both transporters are also able to transport glucose, highlighting the preference of A. nidulans for this carbon source. This work provides a basis for future studies which aim at characterizing and/or genetically engineering Aspergillus spp. transporters, which, in addition to glucose, can also internalize other carbon sources, to improve transport and fermentation of non-glucose sugars in S. cerevisiae.
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Affiliation(s)
- Thaila Fernanda dos Reis
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, Ribeirão Preto, SP CEP 14040-903 Brazil
| | | | - Nádia Skorupa Parachin
- Departamento de Biologia Celular, Instituto de Biologia, Universidade de Brasília, Brasília, CEP 70910-900 Brazil
| | | | | | - Laure Nicolas Annick Ries
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, Ribeirão Preto, SP CEP 14040-903 Brazil
| | - Gustavo Henrique Goldman
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café S/N, Ribeirão Preto, SP CEP 14040-903 Brazil
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Eibinger M, Zahel T, Ganner T, Plank H, Nidetzky B. Cellular automata modeling depicts degradation of cellulosic material by a cellulase system with single-molecule resolution. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:56. [PMID: 26962329 PMCID: PMC4784381 DOI: 10.1186/s13068-016-0463-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/19/2016] [Indexed: 05/15/2023]
Abstract
BACKGROUND Enzymatic hydrolysis of cellulose involves the spatiotemporally correlated action of distinct polysaccharide chain cleaving activities confined to the surface of an insoluble substrate. Because cellulases differ in preference for attacking crystalline compared to amorphous cellulose, the spatial distribution of structural order across the cellulose surface imposes additional constraints on the dynamic interplay between the enzymes. Reconstruction of total system behavior from single-molecule activity parameters is a longstanding key goal in the field. RESULTS We have developed a stochastic, cellular automata-based modeling approach to describe degradation of cellulosic material by a cellulase system at single-molecule resolution. Substrate morphology was modeled to represent the amorphous and crystalline phases as well as the different spatial orientations of the polysaccharide chains. The enzyme system model consisted of an internally chain-cleaving endoglucanase (EG) as well as two processively acting, reducing and non-reducing chain end-cleaving cellobiohydrolases (CBHs). Substrate preference (amorphous: EG, CBH II; crystalline: CBH I) and characteristic frequencies for chain cleavage, processive movement, and dissociation were assigned from biochemical data. Once adsorbed, enzymes were allowed to reach surface-exposed substrate sites through "random-walk" lateral diffusion or processive motion. Simulations revealed that slow dissociation of processive enzymes at obstacles obstructing further movement resulted in local jamming of the cellulases, with consequent delay in the degradation of the surface area affected. Exploiting validation against evidence from atomic force microscopy imaging as a unique opportunity opened up by the modeling approach, we show that spatiotemporal characteristics of cellulose surface degradation by the system of synergizing cellulases were reproduced quantitatively at the nanometer resolution of the experimental data. This in turn gave useful prediction of the soluble sugar release rate. CONCLUSIONS Salient dynamic features of cellulose surface degradation by different cellulases acting in synergy were reproduced in simulations in good agreement with evidence from high-resolution visualization experiments. Due to the single-molecule resolution of the modeling approach, the utility of the presented model lies not only in predicting system behavior but also in elucidating inherently complex (e.g., stochastic) phenomena involved in enzymatic cellulose degradation. Thus, it creates synergy with experiment to advance the mechanistic understanding for improved application.
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Affiliation(s)
- Manuel Eibinger
- />Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, 8010 Graz, Austria
| | - Thomas Zahel
- />Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, 8010 Graz, Austria
| | - Thomas Ganner
- />Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Harald Plank
- />Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
- />Graz Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz, Austria
| | - Bernd Nidetzky
- />Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, 8010 Graz, Austria
- />Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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Bhagia S, Li H, Gao X, Kumar R, Wyman CE. Flowthrough pretreatment with very dilute acid provides insights into high lignin contribution to biomass recalcitrance. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:245. [PMID: 27833657 PMCID: PMC5103384 DOI: 10.1186/s13068-016-0660-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/01/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND Flowthrough pretreatment is capable of removing much higher quantities of hemicellulose and lignin from lignocellulosic biomass than batch pretreatment performed at otherwise similar conditions. Comparison of these two pretreatment configurations for sugar yields and lignin removal can provide insights into lignocellulosic biomass deconstruction. Therefore, we applied liquid hot water (LHW) and extremely dilute acid (EDA, 0.05%) flowthrough and batch pretreatments of poplar at two temperatures and the same pretreatment severity for the solids. Composition of solids, sugar mass distribution with pretreatment, sugar yields, and lignin removal from pretreatment and enzymatic hydrolysis were measured. RESULTS Flowthrough aqueous pretreatment of poplar showed between 63 and 69% lignin removal at both 140 and 180 °C, while batch pretreatments showed about 20 to 33% lignin removal at similar conditions. Extremely dilute acid slightly enhanced lignin removal from solids with flowthrough pretreatment at both pretreatment temperatures. However, extremely dilute acid batch pretreatment did realize greater than 70% xylan yields largely in the form of monomeric xylose. Close to 100% total sugar yields were measured from LHW and EDA flowthrough pretreatments and one batch EDA pretreatment at 180 °C. The high lignin removal by flowthrough pretreatment enhanced cellulose digestibility compared to batch pretreatment, consistent with lignin being a key contributor to biomass recalcitrance. Furthermore, solids from 180 °C flowthrough pretreatment were much more digestible than solids pretreated at 140 °C despite similar lignin and extensive hemicellulose removal. CONCLUSIONS Results with flowthrough pretreatment show that about 65-70% of the lignin is solubilized and removed before it can react further to form low solubility lignin rich fragments that deposit on the biomass surface in batch operations and hinder enzyme action. The leftover 30-35% lignin in poplar was a key player in biomass recalcitrance to enzymatic deconstruction and it might be more difficult to dislodge from biomass with lower temperature of pretreatment. These results also point to the possibility that hemicellulose removal is more important as an indicator of lignin disruption than in playing a direct role in reducing biomass recalcitrance.
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Affiliation(s)
- Samarthya Bhagia
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, 900 University Ave, Riverside, CA 92521 USA
- Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Ave, Riverside, CA 92507 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
| | - Hongjia Li
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, 900 University Ave, Riverside, CA 92521 USA
- Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Ave, Riverside, CA 92507 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
| | - Xiadi Gao
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, 900 University Ave, Riverside, CA 92521 USA
- Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Ave, Riverside, CA 92507 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
| | - Rajeev Kumar
- Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Ave, Riverside, CA 92507 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
| | - Charles E. Wyman
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, 900 University Ave, Riverside, CA 92521 USA
- Center for Environmental Research and Technology, Bourns College of Engineering, University of California Riverside, 1084 Columbia Ave, Riverside, CA 92507 USA
- BioEnergy Science Center (BESC), Oak Ridge National Laboratory, PO Box 2008 MS6341, Oak Ridge, TN 37831 USA
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Junior AT, Dolce LG, de Oliveira Neto M, Polikarpov I. Xanthomonas campestris expansin-like X domain is a structurally disordered beta-sheet macromolecule capable of synergistically enhancing enzymatic efficiency of cellulose hydrolysis. Biotechnol Lett 2015; 37:2419-26. [DOI: 10.1007/s10529-015-1927-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 08/04/2015] [Indexed: 01/30/2023]
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Hamid SBA, Islam MM, Das R. Cellulase biocatalysis: key influencing factors and mode of action. CELLULOSE 2015; 22:2157-2182. [DOI: 10.1007/s10570-015-0672-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Ishiguro M, Endo T. Effect of the addition of calcium hydroxide on the hydrothermal-mechanochemical treatment of Eucalyptus. BIORESOURCE TECHNOLOGY 2015; 177:298-301. [PMID: 25496951 DOI: 10.1016/j.biortech.2014.10.135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 06/04/2023]
Abstract
The effect of Ca(OH)2 addition on optimization of hydrothermal-mechanochemical pretreatment, which combines hydrothermal and milling treatments, was examined. The highest glucose yield of 90% was achieved in the ball-milled specimen previously treated at 170°C in the presence of 20% Ca(OH)2 per substrate weight. The specific surface area of the substrate was closely correlated with glucose yield, and a larger specific surface area was obtained when treating the specimen at 170°C in the presence of Ca(OH)2 compared to treatment at 170°C without Ca(OH)2. Although the Ca(OH)2-treated specimen was relatively unaffected by delignification, the cleavage of the ester bonds between lignin and hemicellulose was confirmed by FT-IR. This suggests that Ca(OH)2 weakens the substrate structure by loosening the bonds between lignin and hemicellulose as the mechanism to increase the specific surface area regardless of the high lignin content, facilitating the fibrillation of fibers with mechanical milling.
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Affiliation(s)
- Maki Ishiguro
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - Takashi Endo
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
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Payne CM, Knott BC, Mayes HB, Hansson H, Himmel ME, Sandgren M, Ståhlberg J, Beckham GT. Fungal Cellulases. Chem Rev 2015; 115:1308-448. [DOI: 10.1021/cr500351c] [Citation(s) in RCA: 533] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christina M. Payne
- Department
of Chemical and Materials Engineering and Center for Computational
Sciences, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, Kentucky 40506, United States
| | - Brandon C. Knott
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Heather B. Mayes
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Henrik Hansson
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Michael E. Himmel
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mats Sandgren
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Jerry Ståhlberg
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Gregg T. Beckham
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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Vermaas JV, Petridis L, Qi X, Schulz R, Lindner B, Smith JC. Mechanism of lignin inhibition of enzymatic biomass deconstruction. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:217. [PMID: 26697106 PMCID: PMC4687093 DOI: 10.1186/s13068-015-0379-8] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/09/2015] [Indexed: 05/06/2023]
Abstract
BACKGROUND The conversion of plant biomass to ethanol via enzymatic cellulose hydrolysis offers a potentially sustainable route to biofuel production. However, the inhibition of enzymatic activity in pretreated biomass by lignin severely limits the efficiency of this process. RESULTS By performing atomic-detail molecular dynamics simulation of a biomass model containing cellulose, lignin, and cellulases (TrCel7A), we elucidate detailed lignin inhibition mechanisms. We find that lignin binds preferentially both to the elements of cellulose to which the cellulases also preferentially bind (the hydrophobic faces) and also to the specific residues on the cellulose-binding module of the cellulase that are critical for cellulose binding of TrCel7A (Y466, Y492, and Y493). CONCLUSIONS Lignin thus binds exactly where for industrial purposes it is least desired, providing a simple explanation of why hydrolysis yields increase with lignin removal.
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Affiliation(s)
- Josh V. Vermaas
- />UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 37831 Oak Ridge, TN USA
- />Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 61801 Urbana, IL USA
| | - Loukas Petridis
- />UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 37831 Oak Ridge, TN USA
| | - Xianghong Qi
- />UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 37831 Oak Ridge, TN USA
- />Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, 37996 Knoxville, TN USA
| | - Roland Schulz
- />UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 37831 Oak Ridge, TN USA
- />Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, 37996 Knoxville, TN USA
| | - Benjamin Lindner
- />UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 37831 Oak Ridge, TN USA
| | - Jeremy. C. Smith
- />UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 37831 Oak Ridge, TN USA
- />Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, 37996 Knoxville, TN USA
- />University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, P.O.Box 2008, Oak Ridge, TN 37831-6309 USA
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Peciulyte A, Karlström K, Larsson PT, Olsson L. Impact of the supramolecular structure of cellulose on the efficiency of enzymatic hydrolysis. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:56. [PMID: 25870653 PMCID: PMC4394567 DOI: 10.1186/s13068-015-0236-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 03/11/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND The efficiency of enzymatic hydrolysis is reduced by the structural properties of cellulose. Although efforts have been made to explain the mechanism of enzymatic hydrolysis of cellulose by considering the interaction of cellulolytic enzymes with cellulose or the changes in the structure of cellulose during enzymatic hydrolysis, the process of cellulose hydrolysis is not yet fully understood. We have analysed the characteristics of the complex supramolecular structure of cellulose on the nanometre scale in terms of the spatial distribution of fibrils and fibril aggregates, the accessible surface area and the crystallinity during enzymatic hydrolysis. Influence of the porosity of the substrates and the hydrolysability was also investigated. All cellulosic substrates used in this study contained more than 96% cellulose. RESULTS Conversion yields of six cellulosic substrates were as follows, in descending order: nano-crystalline cellulose produced from never-dried soda pulp (NCC-OPHS-ND) > never-dried soda pulp (OPHS-ND) > dried soda pulp (OPHS-D) > Avicel > cotton treated with sodium hydroxide (cotton + NaOH) > cotton. CONCLUSIONS No significant correlations were observed between the yield of conversion and supramolecular characteristics, such as specific surface area (SSA) and lateral fibril dimensions (LFD). A strong correlation was found between the average pore size of the starting material and the enzymatic conversion yield. The degree of crystallinity was maintained during enzymatic hydrolysis of the cellulosic substrates, contradicting previous explanations of the increasing crystallinity of cellulose during enzymatic hydrolysis. Both acid and enzymatic hydrolysis can increase the LFD, but no plausible mechanisms could be identified. The sample with the highest initial degree of crystallinity, NCC-OPHS-ND, exhibited the highest conversion yield, but this was not accompanied by any change in LFD, indicating that the hydrolysis mechanism is not based on lateral erosion.
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Affiliation(s)
- Ausra Peciulyte
- />Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, Gothenburg, SE-412 96 Sweden
| | | | - Per Tomas Larsson
- />Innventia AB, Drottning Kristinas väg 61, Stockholm, SE-114 86 Sweden
- />Wallenberg Wood Science Center, KTH Royal Institute of Technology, Teknikringen 56-58, Stockholm, SE-100 44 Sweden
| | - Lisbeth Olsson
- />Department of Biology and Biological Engineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, Gothenburg, SE-412 96 Sweden
- />Wallenberg Wood Science Center, Chalmers University of Technology, Kemigården 4, Gothenburg, SE-412 96 Sweden
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Jalak J, Väljamäe P. Multi-mode binding of Cellobiohydrolase Cel7A from Trichoderma reesei to cellulose. PLoS One 2014; 9:e108181. [PMID: 25265511 PMCID: PMC4180464 DOI: 10.1371/journal.pone.0108181] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 08/19/2014] [Indexed: 01/26/2023] Open
Abstract
Enzymatic hydrolysis of recalcitrant polysaccharides like cellulose takes place on the solid-liquid interface. Therefore the adsorption of enzymes to the solid surface is a pre-requisite for catalysis. Here we used enzymatic activity measurements with fluorescent model-substrate 4-methyl-umbelliferyl-β-D-lactoside for sensitive monitoring of the binding of cellobiohydrolase TrCel7A from Trichoderma reesei to bacterial cellulose (BC). The binding at low nanomolar free TrCel7A concentrations was exclusively active site mediated and was consistent with Langmuir's one binding site model with Kd and Amax values of 2.9 nM and 126 nmol/g BC, respectively. This is the strongest binding observed with non-complexed cellulases and apparently represents the productive binding of TrCel7A to cellulose chain ends on the hydrophobic face of BC microfibril. With increasing free TrCel7A concentrations the isotherm gradually deviated from the Langmuir's one binding site model. This was caused by the increasing contribution of lower affinity binding modes that included both active site mediated binding and non-productive binding with active site free from cellulose chain. The binding of TrCel7A to BC was found to be only partially reversible. Furthermore, the isotherm was dependent on the concentration of BC with more efficient binding observed at lower BC concentrations. The phenomenon can be ascribed to the BC concentration dependent aggregation of BC microfibrils with concomitant reduction of specific surface area.
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Affiliation(s)
- Jürgen Jalak
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
- * E-mail:
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Bornscheuer U, Buchholz K, Seibel J. Enzymatic degradation of (ligno)cellulose. Angew Chem Int Ed Engl 2014; 53:10876-93. [PMID: 25136976 DOI: 10.1002/anie.201309953] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Indexed: 11/06/2022]
Abstract
Glycoside-degrading enzymes play a dominant role in the biochemical conversion of cellulosic biomass into low-price biofuels and high-value-added chemicals. New insight into protein functions and substrate structures, the kinetics of recognition, and degradation events has resulted in a substantial improvement of our understanding of cellulose degradation.
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Affiliation(s)
- Uwe Bornscheuer
- Ernst-Moritz-Arndt-Universität Greifswald, Biotechnologie und Enzymkatalyse, Institut für Biochemie, Felix-Hausdorff-Strasse 4, 17487 Greifswald (Germany)
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Peciulyte A, Anasontzis GE, Karlström K, Larsson PT, Olsson L. Morphology and enzyme production of Trichoderma reesei Rut C-30 are affected by the physical and structural characteristics of cellulosic substrates. Fungal Genet Biol 2014; 72:64-72. [PMID: 25093270 DOI: 10.1016/j.fgb.2014.07.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/18/2014] [Accepted: 07/19/2014] [Indexed: 12/20/2022]
Abstract
The industrial production of cellulolytic enzymes is dominated by the filamentous fungus Trichoderma reesei (anamorph of Hypocrea jecorina). In order to develop optimal enzymatic cocktail, it is of importance to understand the natural regulation of the enzyme profile as response to the growth substrate. The influence of the complexity of cellulose on enzyme production by the microorganisms is not understood. In the present study we attempted to understand how different physical and structural properties of cellulose-rich substrates affected the levels and profiles of extracellular enzymes produced by T. reesei. Enzyme production by T. reesei Rut C-30 was studied in submerged cultures on five different cellulose-rich substrates, namely, commercial cellulose Avicel® and industrial-like cellulosic pulp substrates which consist mainly of cellulose, but also contain residual hemicellulose and lignin. In order to evaluate the hydrolysis of the substrates by the fungal enzymes, the spatial polymer distributions were characterised by cross-polarisation magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS (13)C-NMR) in combination with spectral fitting. Proteins in culture supernatants at early and late stages of enzyme production were labeled by Tandem Mass Tags (TMT) and protein profiles were analysed by liquid chromatography-tandem mass spectrometry. The data have been deposited to the ProteomeXchange with identifier PXD001304. In total 124 proteins were identified and quantified in the culture supernatants, including cellulases, hemicellulases, other glycoside hydrolases, lignin-degrading enzymes, auxiliary activity 9 (AA9) family (formerly GH61), supporting activities of proteins and enzymes acting on cellulose, proteases, intracellular proteins and several hypothetical proteins. Surprisingly, substantial differences in the enzyme profiles were found even though there were minor differences in the chemical composition between the cellulose-rich substrates.
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Affiliation(s)
- Ausra Peciulyte
- Department of Chemical and Biological Engineering, Industrial Biotechnology Group, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - George E Anasontzis
- Department of Chemical and Biological Engineering, Industrial Biotechnology Group, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers, SE-412 96 Gothenburg, Sweden
| | | | - Per Tomas Larsson
- Innventia AB, SE-114 86 Stockholm, Sweden; Wallenberg Wood Science Center, KTH, SE-100 44 Stockholm, Sweden
| | - Lisbeth Olsson
- Department of Chemical and Biological Engineering, Industrial Biotechnology Group, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers, SE-412 96 Gothenburg, Sweden.
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Carbohydrate-binding modules of fungal cellulases: occurrence in nature, function, and relevance in industrial biomass conversion. ADVANCES IN APPLIED MICROBIOLOGY 2014; 88:103-65. [PMID: 24767427 DOI: 10.1016/b978-0-12-800260-5.00004-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this review, the present knowledge on the occurrence of cellulases, with a special emphasis on the presence of carbohydrate-binding modules (CBMs) in various fungal strains, has been summarized. The importance of efficient fungal cellulases is growing due to their potential uses in biorefinery processes where lignocellulosic biomasses are converted to platform sugars and further to biofuels and chemicals. Most secreted cellulases studied in detail have a bimodular structure containing an active core domain attached to a CBM. CBMs are traditionally been considered as essential parts in cellulases, especially in cellobiohydrolases. However, presently available genome data indicate that many cellulases lack the binding domains in cellulose-degrading organisms. Recent data also demonstrate that CBMs are not necessary for the action of cellulases and they solely increase the concentration of enzymes on the substrate surfaces. On the other hand, in practical industrial processes where high substrate concentrations with low amounts of water are employed, the enzymes have been shown to act equally efficiently with and without CBM. Furthermore, available kinetic data show that enzymes without CBMs can desorb more readily from the often lignaceous substrates, that is, they are not stuck on the substrates and are thus available for new actions. In this review, the available data on the natural habitats of different wood-degrading organisms (with emphasis on the amount of water present during wood degradation) and occurrence of cellulose-binding domains in their genome have been assessed in order to identify evolutionary advantages for the development of CBM-less cellulases in nature.
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Particulate size of microalgal biomass affects hydrolysate properties and bioethanol concentration. BIOMED RESEARCH INTERNATIONAL 2014; 2014:435631. [PMID: 24971327 PMCID: PMC4058105 DOI: 10.1155/2014/435631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/03/2014] [Accepted: 05/06/2014] [Indexed: 11/21/2022]
Abstract
Effective optimization of microalgae-to-bioethanol process systems hinges on an in-depth characterization of key process parameters relevant to the overall bioprocess engineering. One of the such important variables is the biomass particle size distribution and the effects on saccharification levels and bioethanol titres. This study examined the effects of three different microalgal biomass particle size ranges, 35 μm ≤ x ≤ 90 μm, 125 μm ≤ x ≤ 180 μm, and 295 μm ≤ x ≤ 425 μm, on the degree of enzymatic hydrolysis and bioethanol production. Two scenarios were investigated: single enzyme hydrolysis (cellulase) and double enzyme hydrolysis (cellulase and cellobiase). The glucose yield from biomass in the smallest particle size range (35 μm ≤ x ≤ 90 μm) was the highest, 134.73 mg glucose/g algae, while the yield from biomass in the larger particle size range (295 μm ≤ x ≤ 425 μm) was 75.45 mg glucose/g algae. A similar trend was observed for bioethanol yield, with the highest yield of 0.47 g EtOH/g glucose obtained from biomass in the smallest particle size range. The results have shown that the microalgal biomass particle size has a significant effect on enzymatic hydrolysis and bioethanol yield.
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