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de Jesus CG, da Rocha Rodrigues R, da Silva CAM, Péres LO. Artificial neural networks in the modeling of the catalytic activity of a biosensor composed of conjugated polymers and urease. Anal Bioanal Chem 2024; 416:1217-1227. [PMID: 38180497 DOI: 10.1007/s00216-023-05114-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/26/2023] [Accepted: 12/11/2023] [Indexed: 01/06/2024]
Abstract
Thin films of conjugated polymer and enzyme can be used to unravel the interaction between components in a biosensor. Using artificial neural networks (ANNs) improves data interpretability and helps construct models with great capacity for classifying and processing information. The present work used kinetic data from the catalytic activity of urease immobilized in different conjugated polymers to create ANN models using time, substrate concentration, and absorbance as input variables since the models had absorbance in a posterior instant as output value to explore the predictivity of the ANNs. The performance of the models was evaluated by Pearson's correlation coefficient (ρ) and mean squared error (MSE) values. After the learning process, a series of new experiments were performed to verify the generality of the models. As the main results, the best ANN model presented 0.9980 and 3.0736 × 10-5 for ρ and MSE, respectively. For the simulation step, intermediary values of substrate concentration were used. The mean absolute percentage error (MAPE) values were 3.34, 3.07, and 3.78 for 12 mM, 22 mM, and 32 mM concentrations, respectively. Overall, with the simulations, it was possible to ascertain the interpolatory capacity of the model, which has a learning mechanism based on absorbance and time as variables. Thus, the potential of ANNs would be in their use in pre-evaluations, helping to determine the substrate concentration at which there is higher catalytic activity or in determining the linear range of the sensor.
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Affiliation(s)
- Cléber Gomes de Jesus
- Laboratory of Hybrid Materials, Federal University of São Paulo, Diadema, SP, Brazil
| | | | | | - Laura Oliveira Péres
- Laboratory of Hybrid Materials, Federal University of São Paulo, Diadema, SP, Brazil.
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Lebas B, Paës G. Bioinspired Polymer Assemblies of Plant Cell Walls for Measuring Protein-Carbohydrate Interactions by FRAP. Methods Mol Biol 2023; 2657:151-162. [PMID: 37149529 DOI: 10.1007/978-1-0716-3151-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The interactions of proteins involved in plant cell wall hydrolysis, such as enzymes and CBMs, significantly determine their role and efficiency. In order to go beyond the characterization of interactions with simple ligands, bioinspired assemblies combined with the measurement of diffusion and interaction by FRAP offer a relevant alternative for highlighting the importance of different parameters related to the protein affinity and to the polymer type and organization in the assembly.
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Affiliation(s)
- Berangère Lebas
- Fractionation of AgroResources and Environment (FARE) laboratory, INRAE, Université de Reims Champagne-Ardenne, Reims, France
| | - Gabriel Paës
- Fractionation of AgroResources and Environment (FARE) laboratory, INRAE, Université de Reims Champagne-Ardenne, Reims, France.
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Ranganathan S, Mahesh S, Suresh S, Nagarajan A, Z Sen T, M Yennamalli R. Experimental and computational studies of cellulases as bioethanol enzymes. Bioengineered 2022; 13:14028-14046. [PMID: 35730402 PMCID: PMC9345620 DOI: 10.1080/21655979.2022.2085541] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bioethanol industries and bioprocesses have many challenges that constantly impede commercialization of the end product. One of the bottlenecks in the bioethanol industry is the challenge of discovering highly efficient catalysts that can improve biomass conversion. The current promising bioethanol conversion catalysts are microorganism-based cellulolytic enzymes, but lack optimization for high bioethanol conversion, due to biological and other factors. A better understanding of molecular underpinnings of cellulolytic enzyme mechanisms and significant ways to improve them can accelerate the bioethanol commercial production process. In order to do this, experimental methods are the primary choice to evaluate and characterize cellulase’s properties, but they are time-consuming and expensive. A time-saving, complementary approach involves computational methods that evaluate the same properties and improves our atomistic-level understanding of enzymatic mechanism of action. Theoretical methods in many cases have proposed research routes for subsequent experimental testing and validation, reducing the overall research cost. Having a plethora of tools to evaluate cellulases and the yield of the enzymatic process will aid in planning more optimized experimental setups. Thus, there is a need to connect the computational evaluation methods with the experimental methods to overcome the bottlenecks in the bioethanol industry. This review discusses various experimental and computational methods and their use in evaluating the multiple properties of cellulases.
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Affiliation(s)
- Shrivaishnavi Ranganathan
- Department of Biotechnology, School of Chemical and Biotechnology, SASTRA Deemed to be University, Tirumalaisamudram, Thanjavur, India
| | - Sankar Mahesh
- Department of Biotechnology, School of Chemical and Biotechnology, SASTRA Deemed to be University, Tirumalaisamudram, Thanjavur, India
| | - Sruthi Suresh
- Department of Biotechnology, School of Chemical and Biotechnology, SASTRA Deemed to be University, Tirumalaisamudram, Thanjavur, India
| | - Ayshwarya Nagarajan
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed to be University, Tirumalaisamudram, Thanjavur, India
| | - Taner Z Sen
- S. Department of Agriculture, Agricultural Research Service, Crop Improvement and Genetics Research UnitU., California, USA
| | - Ragothaman M Yennamalli
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed to be University, Tirumalaisamudram, Thanjavur, India
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Leroy A, Falourd X, Foucat L, Méchin V, Guillon F, Paës G. Evaluating polymer interplay after hot water pretreatment to investigate maize stem internode recalcitrance. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:164. [PMID: 34332625 PMCID: PMC8325808 DOI: 10.1186/s13068-021-02015-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/21/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. RESULTS HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β-O-4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in [Formula: see text], [Formula: see text] and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5-15 nm pore size range. CONCLUSION The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.
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Affiliation(s)
- Amandine Leroy
- INRAE, UR 1268 BIA, 44316, Nantes, France
- Université de Reims Champagne Ardenne, INRAE, FARE, UMR A614, 51100, Reims, France
| | - Xavier Falourd
- INRAE, UR 1268 BIA, 44316, Nantes, France
- INRAE, BIBS Facility, 44316, Nantes, France
| | - Loïc Foucat
- INRAE, UR 1268 BIA, 44316, Nantes, France
- INRAE, BIBS Facility, 44316, Nantes, France
| | - Valérie Méchin
- INRAE, Institut Jean-Pierre Bourgin, 78026, Versailles, France
| | | | - Gabriel Paës
- Université de Reims Champagne Ardenne, INRAE, FARE, UMR A614, 51100, Reims, France.
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Evolution of Fungal Carbohydrate-Active Enzyme Portfolios and Adaptation to Plant Cell-Wall Polymers. J Fungi (Basel) 2021; 7:jof7030185. [PMID: 33807546 PMCID: PMC7998857 DOI: 10.3390/jof7030185] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/25/2021] [Accepted: 02/25/2021] [Indexed: 12/21/2022] Open
Abstract
The postindustrial era is currently facing two ecological challenges. First, the rise in global temperature, mostly caused by the accumulation of carbon dioxide (CO2) in the atmosphere, and second, the inability of the environment to absorb the waste of human activities. Fungi are valuable levers for both a reduction in CO2 emissions, and the improvement of a circular economy with the optimized valorization of plant waste and biomass. Soil fungi may promote plant growth and thereby increase CO2 assimilation via photosynthesis or, conversely, they may prompt the decomposition of dead organic matter, and thereby contribute to CO2 emissions. The strategies that fungi use to cope with plant-cell-wall polymers and access the saccharides that they use as a carbon source largely rely on the secretion of carbohydrate-active enzymes (CAZymes). In the past few years, comparative genomics and phylogenomics coupled with the functional characterization of CAZymes significantly improved the understanding of their evolution in fungal genomes, providing a framework for the design of nature-inspired enzymatic catalysts. Here, we provide an overview of the diversity of CAZyme enzymatic systems employed by fungi that exhibit different substrate preferences, different ecologies, or belong to different taxonomical groups for lignocellulose degradation.
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Enzymes to unravel bioproducts architecture. Biotechnol Adv 2020; 41:107546. [PMID: 32275940 DOI: 10.1016/j.biotechadv.2020.107546] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/20/2020] [Accepted: 04/03/2020] [Indexed: 11/20/2022]
Abstract
Enzymes are essential and ubiquitous biocatalysts involved in various metabolic pathways and used in many industrial processes. Here, we reframe enzymes not just as biocatalysts transforming bioproducts but also as sensitive probes for exploring the structure and composition of complex bioproducts, like meat tissue, dairy products and plant materials, in both food and non-food bioprocesses. This review details the global strategy and presents the most recent investigations to prepare and use enzymes as relevant probes, with a focus on glycoside-hydrolases involved in plant deconstruction and proteases and lipases involved in food digestion. First, to expand the enzyme repertoire to fit bioproduct complexity, novel enzymes are mined from biodiversity and can be artificially engineered. Enzymes are further characterized by exploring sequence/structure/dynamics/function relationships together with the environmental factors influencing enzyme interactions with their substrates. Then, the most advanced experimental and theoretical approaches developed for exploring bioproducts at various scales (from nanometer to millimeter) using active and inactive enzymes as probes are illustrated. Overall, combining multimodal and multiscale approaches brings a better understanding of native-form or transformed bioproduct architecture and composition, and paves the way to mainstream the use of enzymes as probes.
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Zerva A, Pentari C, Grisel S, Berrin JG, Topakas E. A new synergistic relationship between xylan-active LPMO and xylobiohydrolase to tackle recalcitrant xylan. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:142. [PMID: 32793303 PMCID: PMC7419196 DOI: 10.1186/s13068-020-01777-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/29/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND Hemicellulose accounts for a significant part of plant biomass, and still poses a barrier to the efficient saccharification of lignocellulose. The recalcitrant part of hemicellulose is a serious impediment to the action of cellulases, despite the use of xylanases in the cellulolytic cocktail mixtures. However, the complexity and variety of hemicelluloses in different plant materials require the use of highly specific enzymes for a complete breakdown. Over the last few years, new fungal enzymes with novel activities on hemicelluloses have emerged. In the present study, we explored the synergistic relationships of the xylan-active AA14 lytic polysaccharide monooxygenase (LPMO), PcAA14B, with the recently discovered glucuronoxylan-specific xylanase TtXyn30A, of the (sub)family GH30_7, displaying xylobiohydrolase activity, and with commercial cellobiohydrolases, on pretreated natural lignocellulosic substrates. RESULTS PcAA14B and TtXyn30A showed a strong synergistic interaction on the degradation of the recalcitrant part of xylan. PcAA14B was able to increase the release of xylobiose from TtXyn30A, showing a degree of synergism (DS) of 3.8 on birchwood cellulosic fibers, and up to 5.7 on pretreated beechwood substrates. The increase in activity was dose- and time- dependent. A screening study on beechwood materials pretreated with different methods showed that the effect of the PcAA14B-TtXyn30A synergism was more prominent on substrates with low hemicellulose content, indicating that PcAA14B is mainly active on the recalcitrant part of xylan, which is in close proximity to the underlying cellulose fibers. Simultaneous addition of both enzymes resulted in higher DS than sequential addition. Moreover, PcAA14B was found to enhance cellobiose release from cellobiohydrolases during hydrolysis of pretreated lignocellulosic substrates, as well as microcrystalline cellulose. CONCLUSIONS The results of the present study revealed a new synergistic relationship not only among two recently discovered xylan-active enzymes, the LPMO PcAA14B, and the GH30_7 glucuronoxylan-active xylobiohydrolase TtXyn30A, but also among PcAA14B and cellobiohydrolases. We hypothesize that PcAA14B creates free ends in the xylan polymer, which can be used as targets for the action of TtXyn30A. The results are of special importance for the design of next-generation enzymatic cocktails, able to efficiently remove hemicelluloses, allowing complete saccharification of cellulose in plant biomass.
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Affiliation(s)
- Anastasia Zerva
- Industrial Biotechnology and Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
- INRAE, Aix Marseille University, Biodiversité Et Biotechnologie Fongiques (BBF), UMR1163, 13009 Marseille, France
| | - Christina Pentari
- Industrial Biotechnology and Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Sacha Grisel
- INRAE, Aix Marseille University, Biodiversité Et Biotechnologie Fongiques (BBF), UMR1163, 13009 Marseille, France
| | - Jean-Guy Berrin
- INRAE, Aix Marseille University, Biodiversité Et Biotechnologie Fongiques (BBF), UMR1163, 13009 Marseille, France
| | - Evangelos Topakas
- Industrial Biotechnology and Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
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Deng Z, Xia A, Liao Q, Zhu X, Huang Y, Fu Q. Laccase pretreatment of wheat straw: effects of the physicochemical characteristics and the kinetics of enzymatic hydrolysis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:159. [PMID: 31249622 PMCID: PMC6589886 DOI: 10.1186/s13068-019-1499-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 06/14/2019] [Indexed: 05/15/2023]
Abstract
BACKGROUND Wheat straw, the most abundant lignocellulosic biomass in China, is rich in cellulose that can be hydrolyzed and then converted into biofuels, such as bioethanol and biohydrogen. However, the accessibility of cellulose and the enzyme activity are greatly reduced in the presence of lignin. This significantly increases the enzyme cost in the saccharification, which hampers industrial production of lignocellulosic biofuels. In this study, a laccase treatment system mediated by 1-hydroxybenzotriazole was employed to modify and degrade lignin to enhance subsequent enzymatic saccharification of wheat straw. A kinetic model considering enzyme adsorption on lignin was proposed to estimate the saccharification performance. RESULTS Fourier transform infrared spectroscopy (FTIR) analyses showed that the peak intensity of lignin structure characteristics significantly changed after laccase-mediated system (LMS) treatment. 2D-nuclear magnetic resonance (NMR) analyses indicated that the aromatic ether bonds were cleaved and that guaiacyl (G) was oxidized after LMS treatment. X-ray diffraction (XRD) analyses suggested that the crystallinity of lignocellulose increased due to the partial degradation of lignin. As a result, the nonproductive adsorption of the enzyme on lignin was reduced by 28%, while the reducing sugar yield increased by 26%. A semi-empirical kinetic model was used to estimate the reducing sugar yield, the initial hydrolysis rate (K M ) and deactivation rate coefficient (α) of LMS-pretreated wheat straw were 0.157 (h-1) and 0.214 (h-1), respectively. The model showed high accuracy (predicting error < 10%) for describing the behavior of laccase-treated wheat straw hydrolysis when the solid loading is < 5%. CONCLUSIONS The adsorption ability of the enzyme to lignin was reduced after LMS pretreatment. Physicochemical analyses showed that the chemical groups of lignin and lignocellulose were changed, with the crystallinity of the lignocellulose increasing after LMS treatment. A semi-empirical kinetic model was proposed to estimate the reducing sugar yield, which showed high accuracy for predicting the hydrolysis performance of laccase-treated wheat straw.
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Affiliation(s)
- Zhichao Deng
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, 400044 China
- Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044 China
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, 400044 China
- Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044 China
| | - Qiang Liao
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, 400044 China
- Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044 China
| | - Xianqing Zhu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, 400044 China
- Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044 China
| | - Yun Huang
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, 400044 China
- Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044 China
| | - Qian Fu
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, 400044 China
- Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044 China
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Paës G, Habrant A, Terryn C. Fluorescent Nano-Probes to Image Plant Cell Walls by Super-Resolution STED Microscopy. PLANTS 2018; 7:plants7010011. [PMID: 29415498 PMCID: PMC5874600 DOI: 10.3390/plants7010011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 01/28/2018] [Accepted: 02/02/2018] [Indexed: 11/21/2022]
Abstract
Lignocellulosic biomass is a complex network of polymers making up the cell walls of plants. It represents a feedstock of sustainable resources to be converted into fuels, chemicals, and materials. Because of its complex architecture, lignocellulose is a recalcitrant material that requires some pretreatments and several types of catalysts to be transformed efficiently. Gaining more knowledge in the architecture of plant cell walls is therefore important to understand and optimize transformation processes. For the first time, super-resolution imaging of poplar wood samples has been performed using the Stimulated Emission Depletion (STED) technique. In comparison to standard confocal images, STED reveals new details in cell wall structure, allowing the identification of secondary walls and middle lamella with fine details, while keeping open the possibility to perform topochemistry by the use of relevant fluorescent nano-probes. In particular, the deconvolution of STED images increases the signal-to-noise ratio so that images become very well defined. The obtained results show that the STED super-resolution technique can be easily implemented by using cheap commercial fluorescent rhodamine-PEG nano-probes which outline the architecture of plant cell walls due to their interaction with lignin. Moreover, the sample preparation only requires easily-prepared plant sections of a few tens of micrometers, in addition to an easily-implemented post-treatment of images. Overall, the STED super-resolution technique in combination with a variety of nano-probes can provide a new vision of plant cell wall imaging by filling in the gap between classical photon microscopy and electron microscopy.
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Affiliation(s)
- Gabriel Paës
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, 2 Esplanade Roland Garros, 51100 Reims, France.
| | - Anouck Habrant
- FARE Laboratory, INRA, Université de Reims Champagne-Ardenne, 2 Esplanade Roland Garros, 51100 Reims, France.
| | - Christine Terryn
- Plateforme d'Imagerie Cellulaire et Tissulaire (PICT), Université de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, 51100 Reims, France.
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Rodygin KS, Werner I, Ananikov VP. A Green and Sustainable Route to Carbohydrate Vinyl Ethers for Accessing Bioinspired Materials with a Unique Microspherical Morphology. CHEMSUSCHEM 2018; 11:292-298. [PMID: 28898575 DOI: 10.1002/cssc.201701489] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/07/2017] [Indexed: 06/07/2023]
Abstract
Synthesizing chemicals and materials from renewable sources is one of the main aims of modern science. Carbohydrates represent excellent renewable natural raw materials that are ecofriendly, inexpensive, and biologically compatible. A green procedure has been developed for the vinylation of carbohydrates by using readily available calcium carbide. Various carbohydrates were utilized as starting materials, resulting in mono-, di-, and tetravinyl ethers in high to excellent yields (81-92 %). The synthesized biobased vinyl ethers were utilized as monomers in free radical and cationic polymerizations. A unique combination of a smooth surface and intrinsic microcompartments was achieved in the synthesized materials. Two types of biobased materials were prepared involving microspheres and intrinsic hollow compartments in polymers. Scanning electron microscopy with built-in ion beam cutting was applied to reveal the spatial hierarchical structures in 3D space.
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Affiliation(s)
- Konstantin S Rodygin
- Saint Petersburg State University, Universitetskii prospect, 26, Petergof, Russia
| | - Irina Werner
- Saint Petersburg State University, Universitetskii prospect, 26, Petergof, Russia
| | - Valentine P Ananikov
- Saint Petersburg State University, Universitetskii prospect, 26, Petergof, Russia
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect, 47, Moscow, Russia
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Terryn C, Paës G, Spriet C. FRET-SLiM on native autofluorescence: a fast and reliable method to study interactions between fluorescent probes and lignin in plant cell wall. PLANT METHODS 2018; 14:74. [PMID: 30154910 PMCID: PMC6109981 DOI: 10.1186/s13007-018-0342-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/17/2018] [Indexed: 05/20/2023]
Abstract
BACKGROUND Lignocellulosic biomass is a complex network of polymers making the cell walls of plants. It represents a feedstock of sustainable resources to be converted into fuels, chemicals and materials. Because of its complex architecture, lignocellulose is a recalcitrant material that necessitates some pretreatments and several types of catalysts to be transformed efficiently. In particular, enzymes degrading lignocellulose can become inactivated due to their binding to lignin through non-specific interactions, leading to a loss in catalytic efficiency of industrial processes. Gaining more knowledge in the strength of interactions would allow optimizing enzymes and selecting appropriate pretreatments. RESULTS Measuring interactions directly in plant cell wall can theoretically be performed using confocal fluorescence techniques by evaluating fluorescence resonance energy transfer (FRET) between compatible fluorophores. In this study, autofluorescence of plant cell wall, mainly originating from lignin, was considered as a donor fluorophore while the acceptor was a common rhodamine-based fluorescent probe. To overcome complex plant cell wall fluorescence, which limits FRET analysis by standard techniques, we have developed an original approach, combining spectral and lifetime measurements. It consists in (1) dissecting autofluorescence signal in each spectral channel, (2) optimizing spectral channel choice for lifetime measurements and (3) achieving an unambiguous FRET signature with an autofluorescent donor fluorophore. Interactions between rhodamine-based probes of various sizes and untreated or pretreated wheat sample were evaluated, showing it was possible to discriminate interactions at the nano-scale, revealing some accessibility differences and the effect of pretreatment. CONCLUSIONS SLiM measurement allows precise estimation of the optimal spectral range for FRET measurement. SLiM response allows for the first time doubtless FRET measurements between lignin as a donor, and an acceptor fluorophore with high accuracy and sensitivity related to lifetime decrease studies. As demonstrated, it thus becomes possible to measure interactions of fluorescent probes directly inside plant cell wall samples. This approach can thus be applied to various fields such as lignocellulose deconstruction to optimize the action of enzymes or plant cell wall development to assay in situ the biosynthesis of lignin.
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Affiliation(s)
- Christine Terryn
- PICT Platform, University of Reims Champagne-Ardenne, 51 rue Cognacq-Jay, 51100 Reims, France
| | - Gabriel Paës
- Fractionation of AgroResources and Environment (FARE) Laboratory, INRA, University of Reims Champagne-Ardenne, 2 Esplanade Roland-Garros, 51100 Reims, France
| | - Corentin Spriet
- TISBio, Unité de Glycobiologie Structurale et Fonctionnelle (UGSF), CNRS, UMR 8576, Université de Lille, 59000 Lille, France
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Herbaut M, Zoghlami A, Paës G. Dynamical assessment of fluorescent probes mobility in poplar cell walls reveals nanopores govern saccharification. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:271. [PMID: 30305844 PMCID: PMC6169017 DOI: 10.1186/s13068-018-1267-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/20/2018] [Indexed: 05/15/2023]
Abstract
BACKGROUND Improving lignocellulolytic enzymes' diffusion and accessibility to their substrate in the plant cell walls is recognised as a critical issue for optimising saccharification. Although many chemical features are considered as detrimental to saccharification, enzymes' dynamics within the cell walls remains poorly explored and understood. To address this issue, poplar fragments were submitted to hot water and ionic liquid pretreatments selected for their contrasted effects on both the structure and composition of lignocellulose. In addition to chemical composition and porosity analyses, the diffusion of polyethylene glycol probes of different sizes was measured at three different time points during the saccharification. RESULTS Probes' diffusion was mainly affected by probes size and pretreatments but only slightly by saccharification time. This means that, despite the removal of polysaccharides during saccharification, diffusion of probes was not improved since they became hindered by changes in lignin conformation, whose relative amount increased over time. Porosity measurements showed that probes' diffusion was highly correlated with the amount of pores having a diameter at least five times the size of the probes. Testing the relationship with saccharification demonstrated that accessibility of 1.3-1.7-nm radius probes measured by FRAP on non-hydrolysed samples was highly correlated with poplar digestibility together with the measurement of initial porosity on the range 5-20 nm. CONCLUSION Mobility measurements performed before hydrolysis can serve to explain and even predict saccharification with accuracy. The discrepancy observed between probes' size and pores' diameters to explain accessibility is likely due to biomass features such as lignin content and composition that prevent probes' diffusion through non-specific interactions probably leading to pores' entanglements.
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Affiliation(s)
- Mickaël Herbaut
- Fractionation of AgroResources and Environment (FARE) Laboratory, INRA, University of Reims Champagne-Ardenne, Reims, France
| | - Aya Zoghlami
- Fractionation of AgroResources and Environment (FARE) Laboratory, INRA, University of Reims Champagne-Ardenne, Reims, France
| | - Gabriel Paës
- Fractionation of AgroResources and Environment (FARE) Laboratory, INRA, University of Reims Champagne-Ardenne, Reims, France
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Thévenot J, Cauty C, Legland D, Dupont D, Floury J. Pepsin diffusion in dairy gels depends on casein concentration and microstructure. Food Chem 2017; 223:54-61. [DOI: 10.1016/j.foodchem.2016.12.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 01/23/2023]
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Miyauchi S, Navarro D, Grisel S, Chevret D, Berrin JG, Rosso MN. The integrative omics of white-rot fungus Pycnoporus coccineus reveals co-regulated CAZymes for orchestrated lignocellulose breakdown. PLoS One 2017; 12:e0175528. [PMID: 28394946 PMCID: PMC5386290 DOI: 10.1371/journal.pone.0175528] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 03/27/2017] [Indexed: 01/22/2023] Open
Abstract
Innovative green technologies are of importance for converting plant wastes into renewable sources for materials, chemicals and energy. However, recycling agricultural and forestry wastes is a challenge. A solution may be found in the forest. Saprotrophic white-rot fungi are able to convert dead plants into consumable carbon sources. Specialized fungal enzymes can be utilized for breaking down hard plant biopolymers. Thus, understanding the enzymatic machineries of such fungi gives us hints for the efficient decomposition of plant materials. Using the saprotrophic white-rot fungus Pycnoporus coccineus as a fungal model, we examined the dynamics of transcriptomic and secretomic responses to different types of lignocellulosic substrates at two time points. Our integrative omics pipeline (SHIN+GO) enabled us to compress layers of biological information into simple heatmaps, allowing for visual inspection of the data. We identified co-regulated genes with corresponding co-secreted enzymes, and the biological roles were extrapolated with the enriched Carbohydrate-Active Enzyme (CAZymes) and functional annotations. We observed the fungal early responses for the degradation of lignocellulosic substrates including; 1) simultaneous expression of CAZy genes and secretion of the enzymes acting on diverse glycosidic bonds in cellulose, hemicelluloses and their side chains or lignin (i.e. hydrolases, esterases and oxido-reductases); 2) the key role of lytic polysaccharide monooxygenases (LPMO); 3) the early transcriptional regulation of lignin active peroxidases; 4) the induction of detoxification processes dealing with biomass-derived compounds; and 5) the frequent attachments of the carbohydrate binding module 1 (CBM1) to enzymes from the lignocellulose-responsive genes. Our omics combining methods and related biological findings may contribute to the knowledge of fungal systems biology and facilitate the optimization of fungal enzyme cocktails for various industrial applications.
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Affiliation(s)
- Shingo Miyauchi
- Aix-Marseille Université, INRA, UMR 1163, Biodiversité et Biotechnologie Fongiques, BBF, Marseille, France
| | - David Navarro
- Aix-Marseille Université, INRA, UMR 1163, Biodiversité et Biotechnologie Fongiques, BBF, Marseille, France
| | - Sacha Grisel
- Aix-Marseille Université, INRA, UMR 1163, Biodiversité et Biotechnologie Fongiques, BBF, Marseille, France
| | - Didier Chevret
- PAPPSO, Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Jean-Guy Berrin
- Aix-Marseille Université, INRA, UMR 1163, Biodiversité et Biotechnologie Fongiques, BBF, Marseille, France
| | - Marie-Noelle Rosso
- Aix-Marseille Université, INRA, UMR 1163, Biodiversité et Biotechnologie Fongiques, BBF, Marseille, France
- * E-mail:
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Paës G. Bioinspired Assemblies of Plant Cell Walls for Measuring Protein-Carbohydrate Interactions by FRAP. Methods Mol Biol 2017; 1588:169-179. [PMID: 28417368 DOI: 10.1007/978-1-4939-6899-2_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The interactions of proteins involved in plant cell wall hydrolysis, such as enzymes and CBMs, significantly determine their role and efficiency. In order to go beyond the characterization of interactions with simple ligands, bioinspired assemblies combined with the measurement of diffusion and interaction by FRAP offer a relevant alternative for highlighting the importance of different parameters related to the protein affinity and to the assembly.
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Affiliation(s)
- Gabriel Paës
- FARE laboratory, INRA, University of Reims Champagne-Ardenne, 2 esplanade Roland-Garros, 51100, Reims, France.
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Paës G, Habrant A, Ossemond J, Chabbert B. Exploring accessibility of pretreated poplar cell walls by measuring dynamics of fluorescent probes. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:15. [PMID: 28101142 PMCID: PMC5237506 DOI: 10.1186/s13068-017-0704-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 01/06/2017] [Indexed: 05/09/2023]
Abstract
BACKGROUND The lignocellulosic cell wall network is resistant to enzymatic degradation due to the complex chemical and structural features. Pretreatments are thus commonly used to overcome natural recalcitrance of lignocellulose. Characterization of their impact on architecture requires combinatory approaches. However, the accessibility of the lignocellulosic cell walls still needs further insights to provide relevant information. RESULTS Poplar specimens were pretreated using different conditions. Chemical, spectral, microscopic and immunolabeling analysis revealed that poplar cell walls were more altered by sodium chlorite-acetic acid and hydrothermal pretreatments but weakly modified by soaking in aqueous ammonium. In order to evaluate the accessibility of the pretreated poplar samples, two fluorescent probes (rhodamine B-isothiocyanate-dextrans of 20 and 70 kDa) were selected, and their mobility was measured by using the fluorescence recovery after photobleaching (FRAP) technique in a full factorial experiment. The mobility of the probes was dependent on the pretreatment type, the cell wall localization (secondary cell wall and cell corner middle lamella) and the probe size. Overall, combinatory analysis of pretreated poplar samples showed that even the partial removal of hemicellulose contributed to facilitate the accessibility to the fluorescent probes. On the contrary, nearly complete removal of lignin was detrimental to accessibility due to the possible cellulose-hemicellulose collapse. CONCLUSIONS Evaluation of plant cell wall accessibility through FRAP measurement brings further insights into the impact of physicochemical pretreatments on lignocellulosic samples in combination with chemical and histochemical analysis. This technique thus represents a relevant approach to better understand the effect of pretreatments on lignocellulose architecture, while considering different limitations as non-specific interactions and enzyme efficiency.
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Affiliation(s)
- Gabriel Paës
- FARE laboratory, INRA, Université de Reims Champagne-Ardenne, 51100 Reims, France
| | - Anouck Habrant
- FARE laboratory, INRA, Université de Reims Champagne-Ardenne, 51100 Reims, France
| | - Jordane Ossemond
- FARE laboratory, INRA, Université de Reims Champagne-Ardenne, 51100 Reims, France
| | - Brigitte Chabbert
- FARE laboratory, INRA, Université de Reims Champagne-Ardenne, 51100 Reims, France
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