1
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Wu J, Dong Y, Zhang H, Liu J, Renneckar S, Saddler J. Reduced cellulose accessibility slows down enzyme-mediated hydrolysis of cellulose. BIORESOURCE TECHNOLOGY 2023; 371:128647. [PMID: 36681353 DOI: 10.1016/j.biortech.2023.128647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Enzyme-mediated hydrolysis of cellulose always starts with an initial rapid phase, which gradually slows down, sometimes resulting in incomplete cellulose hydrolysis even after prolonged incubation. Although mechanisms such as end-product inhibition are known to play a role, the predominant mechanism appears to be reduced cellulose accessibility to the enzymes. When using Simon's stain to quantify accessibility, the accessibility of mechanically disintegrated and phosphoric acid-swollen cellulose substrates decreased as hydrolysis proceeded. In contrast, the poor initial accessibility of Avicel remained low throughout hydrolysis. However, washing the residual cellulose increased cellulose accessibility, likely due to the removal of tightly bound but non-productive enzymes which blocked access to more active enzymes in solution. Atomic force microscopy (AFM) analysis of the initial and residual cellulose collected when the hydrolysis plateaued, showed an increase in the roughness of the cellulose surface, possibly resulting in the tighter binding of less active cellulases.
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Affiliation(s)
- Jie Wu
- Forest Product Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Yintian Dong
- Forest Product Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Huaiyu Zhang
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Jingyun Liu
- Forest Product Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada; School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Scott Renneckar
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Jack Saddler
- Forest Product Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada.
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2
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Sagarika MS, Parameswaran C, Senapati A, Barala J, Mitra D, Prabhukarthikeyan SR, Kumar A, Nayak AK, Panneerselvam P. Lytic polysaccharide monooxygenases (LPMOs) producing microbes: A novel approach for rapid recycling of agricultural wastes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150451. [PMID: 34607097 DOI: 10.1016/j.scitotenv.2021.150451] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/12/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
Out of the huge quantity of agricultural wastes produced globally, rice straw is one of the most abundant ligno-cellulosic waste. For efficient utilization of these wastes, several cost-effective biological processes are available. The practice of field level in-situ or ex-situ decomposition of rice straw is having less degree of adoption due to its poor decomposition ability within a short time span between rice harvest and sowing of the next crop. Agricultural wastes including rice straw are in general utilized by using lignocellulose degrading microbes for industrial metabolite or compost production. However, bioconversion of crystalline cellulose and lignin present in the waste, into simple molecules is a challenging task. To resolve this issue, researchers have identified a novel new generation microbial enzyme i.e., lytic polysaccharide monooxygenases (LPMOs) and reported that the combination of LPMOs with other glycolytic enzymes are found efficient. This review explains the progress made in LPMOs and their role in lignocellulose bioconversion and the possibility of exploring LPMOs producers for rapid decomposition of agricultural wastes. Also, it provides insights to identify the knowledge gaps in improving the potential of the existing ligno-cellulolytic microbial consortium for efficient utilization of agricultural wastes at industrial and field levels.
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Affiliation(s)
- Mahapatra Smruthi Sagarika
- ICAR - National Rice Research Institute, Cuttack, Odisha 753006, India; Indira Gandhi Agricultural University, Raipur, Chhattisgarh 492012, India
| | | | - Ansuman Senapati
- ICAR - National Rice Research Institute, Cuttack, Odisha 753006, India
| | - Jatiprasad Barala
- ICAR - National Rice Research Institute, Cuttack, Odisha 753006, India
| | - Debasis Mitra
- ICAR - National Rice Research Institute, Cuttack, Odisha 753006, India
| | | | - Anjani Kumar
- ICAR - National Rice Research Institute, Cuttack, Odisha 753006, India
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3
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Zajki-Zechmeister K, Kaira GS, Eibinger M, Seelich K, Nidetzky B. Processive Enzymes Kept on a Leash: How Cellulase Activity in Multienzyme Complexes Directs Nanoscale Deconstruction of Cellulose. ACS Catal 2021; 11:13530-13542. [PMID: 34777910 PMCID: PMC8576811 DOI: 10.1021/acscatal.1c03465] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/11/2021] [Indexed: 12/15/2022]
Abstract
Biological deconstruction of polymer materials gains efficiency from the spatiotemporally coordinated action of enzymes with synergetic function in polymer chain depolymerization. To perpetuate enzyme synergy on a solid substrate undergoing deconstruction, the overall attack must alternate between focusing the individual enzymes locally and dissipating them again to other surface sites. Natural cellulases working as multienzyme complexes assembled on a scaffold protein (the cellulosome) maximize the effect of local concentration yet restrain the dispersion of individual enzymes. Here, with evidence from real-time atomic force microscopy to track nanoscale deconstruction of single cellulose fibers, we show that the cellulosome forces the fiber degradation into the transversal direction, to produce smaller fragments from multiple local attacks ("cuts"). Noncomplexed enzymes, as in fungal cellulases or obtained by dissociating the cellulosome, release the confining force so that fiber degradation proceeds laterally, observed as directed ablation of surface fibrils and leading to whole fiber "thinning". Processive cellulases that are enabled to freely disperse evoke the lateral degradation and determine its efficiency. Our results suggest that among natural cellulases, the dispersed enzymes are more generally and globally effective in depolymerization, while the cellulosome represents a specialized, fiber-fragmenting machinery.
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Affiliation(s)
- Krisztina Zajki-Zechmeister
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Gaurav Singh Kaira
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
| | - Manuel Eibinger
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Klara Seelich
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 10-12/1, 8010 Graz, Austria
- Austrian
Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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4
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Anuganti M, Fu H, Ekatan S, Kumar CV, Lin Y. Kinetic Study on Enzymatic Hydrolysis of Cellulose in an Open, Inhibition-Free System. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5180-5192. [PMID: 33872034 DOI: 10.1021/acs.langmuir.1c00115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Due to the complexity of cellulases and the requirement of enzyme adsorption on cellulose prior to reactions, it is difficult to evaluate their reaction with a general mechanistic scheme. Nevertheless, it is of great interest to come up with an approximate analytic description of a valid model for the purpose of developing an intuitive understanding of these complex enzyme systems. Herein, we used the surface plasmonic resonance method to monitor the action of a cellobiohydrolase by itself, as well as its mixture with a synergetic endoglucanase, on the surface of a regenerated model cellulose film, under continuous flow conditions. We found a phenomenological approach by taking advantage of the long steady state of cellulose hydrolysis in the open, inhibition-free system. This provided a direct and reliable way to analyze the adsorption and reaction processes with a minimum number of fitting parameters. We investigated a generalized Langmuir-Michaelis-Menten model to describe a full set of kinetic results across a range of enzyme concentrations, compositions, and temperatures. The overall form of the equations describing the pseudo-steady-state kinetics of the flow-system shares some interesting similarities with the Michaelis-Menten equation. The use of familiar Michaelis-Menten parameters in the analysis provides a unifying framework to study cellulase kinetics. The strategy may provide a shortcut for approaching a quantitative while intuitive understanding of enzymatic degradation of cellulose from top to bottom. The open system approach and the kinetic analysis should be applicable to a variety of cellulases and reaction systems to accelerate the progress in the field.
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Affiliation(s)
- Murali Anuganti
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Hailin Fu
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Stephen Ekatan
- Polymer Program, Institute of Material Sciences, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Challa V Kumar
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yao Lin
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
- Polymer Program, Institute of Material Sciences, University of Connecticut, Storrs, Connecticut 06269, United States
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5
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Mitchell DA, Moreira I, Krieger N. Potential of time-stepping stochastic models as tools for guiding the design and operation of processes for the enzymatic hydrolysis of polysaccharides - A review. BIORESOURCE TECHNOLOGY 2021; 323:124559. [PMID: 33388211 DOI: 10.1016/j.biortech.2020.124559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 06/12/2023]
Abstract
Processes for the enzymatic hydrolysis of polysaccharides in biorefineries are becoming increasingly important. The complex network of reactions involved in polysaccharide hydrolysis can be described by stochastic models that advance in steps of time. Such models have the potential to be important tools for guiding process design and operation, and several have been developed over the last two decades. We evaluate these models. Many of the current stochastic models for the hydrolysis of colloidal polysaccharides use empirical parameters that have no recognized biological meaning. Only one model uses classical parameters of enzyme kinetics, namely specificity constants and saturation constants. Recent stochastic models for the hydrolysis of insoluble cellulose give valuable insights into the molecular-level phenomenon that limit hydrolysis rates. We conclude that, if stochastic models of enzymatic polysaccharide hydrolysis are to become widely used tools for guiding process development, then further improvements are required.
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Affiliation(s)
- David Alexander Mitchell
- Postgraduate Program in Chemical Engineering, Federal University of Paraná, P.O. Box 19011, Central Polytechnic, Curitiba 81531-980, Paraná, Brazil; Department of Biochemistry and Molecular Biology, Federal University of Paraná, P.O. Box 19046, Central Polytechnic, Curitiba 81531-980, Paraná, Brazil
| | - Isabelle Moreira
- Postgraduate Program in Chemical Engineering, Federal University of Paraná, P.O. Box 19011, Central Polytechnic, Curitiba 81531-980, Paraná, Brazil
| | - Nadia Krieger
- Postgraduate Program in Chemical Engineering, Federal University of Paraná, P.O. Box 19011, Central Polytechnic, Curitiba 81531-980, Paraná, Brazil; Department of Chemistry, Federal University of Paraná, P.O. Box 19061, Central Polytechnic, Curitiba 81531-980, Paraná, Brazil.
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6
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Oh Y, Park S, Jung D, Oh KK, Lee SH. Effect of hydrogen bond donor on the choline chloride-based deep eutectic solvent-mediated extraction of lignin from pine wood. Int J Biol Macromol 2020; 165:187-197. [PMID: 32991892 DOI: 10.1016/j.ijbiomac.2020.09.145] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/16/2020] [Accepted: 09/19/2020] [Indexed: 12/21/2022]
Abstract
In this work, twenty-five kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) containing acid, hydroxyl, amide, and binary hydrogen bond donors (HBDs) were prepared and successfully used to pretreat pine wood powder. As a result of the pretreatment, the glucan content in the pretreated biomass was increased, whereas the contents of hemicellulose and lignin were significantly decreased. The biomass pretreatment efficiency of the DESs had improved with increasing the polarity and hydrogen bond acidity (α) of the DESs. Among the studied DESs, ChCl:lactic acid:formic acid (1:1:1) with the highest α value was the most efficient DES in extracting lignin from biomass. The pretreated biomass also showed an enhanced enzymatic saccharification yield owing to the decreased particle size of the biomass and reduced content of hemicellulose and lignin. During the pretreatment process of biomass using DESs, the extracted lignin could be recovered successfully, with a yield of up to 60% and purity of over 90%. The molecular weight of the extracted lignin was much lower than that of the native cellulolytic enzyme lignin. The DES used for pretreatment process could be also successfully reused with high recovery yield of DES and high retention of delignification capacity.
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Affiliation(s)
- Yujin Oh
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Saerom Park
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Dahun Jung
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea
| | - Kyeong Keun Oh
- Department of Chemical Engineering, Dankook University, Yongin 16890, Gyeonggi, South Korea
| | - Sang Hyun Lee
- Department of Biological Engineering, Konkuk University, Seoul 05029, South Korea.
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7
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Tallian C, Rumpler V, Skopek L, Russmayer H, Steiger MG, Vielnascher R, Weinberger S, Pellis A, Vecchiato S, Guebitz GM. Glutathione from recovered glucose as ingredient in antioxidant nanocapsules for triggered flavor delivery. J Mater Chem B 2019. [DOI: 10.1039/c9tb00473d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Glucose recovered via enzymatic hydrolysis of rayon fibers was used for glutathione production by S. cerevisiae. Glutathione was used in combination with HSA and silk fibroin for ultrasound assisted nanocapsules production. Triggered release of flavor substances and antioxidant properties of the nanocapsules was demonstrated.
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Affiliation(s)
- Claudia Tallian
- University of Natural Resources and Life Sciences
- Vienna (BOKU)
- Institute for Environmental Biotechnology
- Department for Agrobiotechnology (IFA-Tulln)
- 3430 Tulln an der Donau
| | - Vanessa Rumpler
- University of Natural Resources and Life Sciences
- Vienna (BOKU)
- Institute for Environmental Biotechnology
- Department for Agrobiotechnology (IFA-Tulln)
- 3430 Tulln an der Donau
| | - Lukas Skopek
- Austrian Centre of Industrial Biotechnology
- 3430 Tulln an der Donau
- Austria
| | - Hannes Russmayer
- University of Natural Resources and Life Sciences
- Department of Biotechnology
- 1190 Vienna
- Austria
| | - Matthias G. Steiger
- Austrian Centre of Industrial Biotechnology
- 3430 Tulln an der Donau
- Austria
- University of Natural Resources and Life Sciences
- Department of Biotechnology
| | - Robert Vielnascher
- University of Natural Resources and Life Sciences
- Vienna (BOKU)
- Institute for Environmental Biotechnology
- Department for Agrobiotechnology (IFA-Tulln)
- 3430 Tulln an der Donau
| | - Simone Weinberger
- University of Natural Resources and Life Sciences
- Vienna (BOKU)
- Institute for Environmental Biotechnology
- Department for Agrobiotechnology (IFA-Tulln)
- 3430 Tulln an der Donau
| | - Alessandro Pellis
- University of York
- Department of Chemistry
- Green Chemistry Centre of Excellence
- Heslington
- UK
| | - Sara Vecchiato
- Austrian Centre of Industrial Biotechnology
- 3430 Tulln an der Donau
- Austria
| | - Georg M. Guebitz
- University of Natural Resources and Life Sciences
- Vienna (BOKU)
- Institute for Environmental Biotechnology
- Department for Agrobiotechnology (IFA-Tulln)
- 3430 Tulln an der Donau
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8
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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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9
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Jain KK, Kumar S, Bhardwaj KN, Kuhad RC. Functional Expression of a Thermostable Endoglucanase from Thermoascus aurantiacus RCKK in Pichia pastoris X-33 and Its Characterization. Mol Biotechnol 2018; 60:736-748. [PMID: 30076532 DOI: 10.1007/s12033-018-0106-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Thermostable cellulases offer several advantages like higher rates of substrate hydrolysis, lowered risk of contamination, and increased flexibility with respect to process design. In the present study, a thermostable native endoglucanase nEG (EC 3.2.1.4) was purified and characterized from T. aurantiacus RCKK. Further, it was cloned in P. pastoris X-33 and processed for over expression. Expression of recombinant endoglucanase (rEG) of molecular size ~ 33 kDa was confirmed by SDS-PAGE and western blotting followed by in gel activity determination by zymogram analysis. Similar to nEG, the purified rEG was characterized to harbor high thermostability while retaining 50% of its initial activity even after 6- and 10-h incubation at 80 and 70 °C, respectively, and exhibited considerable stability in pH range 3.0-7.0. CD spectroscopy revealed more than 20% β-sheets in protein structure consistently when incubated upto 85 °C as a speculated reason for protein high thermostability. Interestingly, both nEG and rEG were found tolerant up to 10% of the presence of 1-ethyl-3-methylimidazolium acetate [C2mim][OAc]. Values of the catalytic constants Km and Vmax for rEG were recorded as 2.5 mg/ml and 303.4 µmol/mg/min, respectively. Thermostability, pH stability, and resistance to the presence of ionic liquid signify the potential applicability of present enzyme in cellulose hydrolysis and enzymatic deinking of recycled paper pulp.
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Affiliation(s)
- Kavish Kumar Jain
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.,Department of Microbiology, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Sandeep Kumar
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Kailash N Bhardwaj
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.,Uttarakhan State Council of Science and Technology [UCOST], Vigyan Dham, Post Office- Jhajra, Dehradun, Uttarakhand, 248007, India
| | - Ramesh Chander Kuhad
- Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. .,Central University of Haryana, Jant-Pali Village, Mahendergarh District, Haryana, 123029, India.
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10
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Wojtusik M, Villar JC, Ladero M, Garcia-Ochoa F. Physico-chemical kinetic modelling of hydrolysis of a steam-explosion pre-treated corn stover: A two-step approach. BIORESOURCE TECHNOLOGY 2018; 268:592-598. [PMID: 30138871 DOI: 10.1016/j.biortech.2018.08.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 08/11/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
A physico-chemical kinetic model for the hydrolysis of pre-treated corn stover is proposed. This model takes into account two reactions in series, the hydrolysis of cellulose to cellobiose and the production of glucose from cellobiose. Experiments have been carried out with an industrial enzymatic cocktail from Trichoderma reesei containing endo and exoglucanases and a very low activity of β-glucosidase. Kinetic parameters were calculated by fitting the proposed model to experimental data of cellulose and glucose concentrations with time. The kinetic parameters fulfilled all relevant statistical and physical criteria. The kinetic model has been validated with published saccharification data regarding differently pre-treated corn stover and enzymatic cocktail, in this case with a very high β-glucosidase activity (as it is common in modern industrial cellulase cocktails). In both cases, the kinetic model proposed could be fitted very appropriately to cellulose hydrolysis data.
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Affiliation(s)
- Mateusz Wojtusik
- Chemical and Materials Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Juan C Villar
- Laboratory of Cellulose and Paper, INIA, Forest Research Center, 28040 Madrid, Spain
| | - Miguel Ladero
- Chemical and Materials Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - Felix Garcia-Ochoa
- Chemical and Materials Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
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11
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de la Torre I, Ravelo M, Segarra S, Tortajada M, Santos VE, Ladero M. Study on the effects of several operational variables on the enzymatic batch saccharification of orange solid waste. BIORESOURCE TECHNOLOGY 2017; 245:906-915. [PMID: 28931207 DOI: 10.1016/j.biortech.2017.08.094] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
In this work, batch enzyme-aided extraction and enzymatic saccharification of blade-milled orange waste was studied. The operation variables for this process were thoroughly analysed. It was determined that batch runs with initial pH values of 5.0 and 5.2 controlled during the first hour, 50°C and 300-500r.p.m. agitation resulted in the best yields, with a limited total and partial first-order enzyme deactivation (for cellulases and polygalacturonidase, respectively). Orange peel waste (OPW) at 6.7% w/w dry solid, 0.22 filter paper units (FPU)/g DS and proportional activities of other enzymes led to over 40g/L free monosaccharides and global yields to glucose over 80%. When using 10.1% w/w DS in these conditions, glucose yield was 63%, with total monosaccharide concentration on top of 50g/L. Similar concentrations were obtained by additional partial drying of OPW to 60% humidity at DS/L ratios near 7.5% (glucose yield >80%).
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Affiliation(s)
- Isabel de la Torre
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Marianela Ravelo
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Silvia Segarra
- BIOPOLIS, S.L., Parc Científic Universitat de València, 46980, Paterna, Valencia, Spain
| | - Marta Tortajada
- BIOPOLIS, S.L., Parc Científic Universitat de València, 46980, Paterna, Valencia, Spain
| | - Victoria E Santos
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Miguel Ladero
- Chemical Engineering Department, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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12
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Single-molecule study of oxidative enzymatic deconstruction of cellulose. Nat Commun 2017; 8:894. [PMID: 29026070 PMCID: PMC5638905 DOI: 10.1038/s41467-017-01028-y] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 08/02/2017] [Indexed: 01/29/2023] Open
Abstract
LPMO (lytic polysaccharide monooxygenase) represents a unique paradigm of cellulosic biomass degradation by an oxidative mechanism. Understanding the role of LPMO in deconstructing crystalline cellulose is fundamental to the enzyme’s biological function and will help to specify the use of LPMO in biorefinery applications. Here we show with real-time atomic force microscopy that C1 and C4 oxidizing types of LPMO from Neurospora crassa (NcLPMO9F, NcLPMO9C) bind to nanocrystalline cellulose with high preference for the very same substrate surfaces that are also used by a processive cellulase (Trichoderma reesei CBH I) to move along during hydrolytic cellulose degradation. The bound LPMOs, however, are immobile during their adsorbed residence time ( ~ 1.0 min for NcLPMO9F) on cellulose. Treatment with LPMO resulted in fibrillation of crystalline cellulose and strongly ( ≥ 2-fold) enhanced the cellulase adsorption. It also increased enzyme turnover on the cellulose surface, thus boosting the hydrolytic conversion. Understanding the role of enzymes in biomass depolymerization is essential for the development of more efficient biorefineries. Here, the authors show by atomic force microscopy the real-time mechanism of cellulose deconstruction by lytic polysaccharide monooxygenases.
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13
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Donaldson L, Vaidya A. Visualising recalcitrance by colocalisation of cellulase, lignin and cellulose in pretreated pine biomass using fluorescence microscopy. Sci Rep 2017; 7:44386. [PMID: 28281670 PMCID: PMC5345003 DOI: 10.1038/srep44386] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/07/2017] [Indexed: 11/08/2022] Open
Abstract
Mapping the location of bound cellulase enzymes provides information on the micro-scale distribution of amenable and recalcitrant sites in pretreated woody biomass for biofuel applications. The interaction of a fluorescently labelled cellulase enzyme cocktail with steam-exploded pine (SEW) was quantified using confocal microscopy. The spatial distribution of Dylight labelled cellulase was quantified relative to lignin (autofluorescence) and cellulose (Congo red staining) by measuring their colocalisation using Pearson correlations. Correlations were greater in cellulose-rich secondary cell walls compared to lignin-rich middle lamella but with significant variations among individual biomass particles. The distribution of cellulose in the pretreated biomass accounted for 30% of the variation in the distribution of enzyme after correcting for the correlation between lignin and cellulose. For the first time, colocalisation analysis was able to quantify the spatial distribution of amenable and recalcitrant sites in relation to the histochemistry of cellulose and lignin. This study will contribute to understanding the role of pretreatment in enzymatic hydrolysis of recalcitrant softwood biomass.
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Affiliation(s)
- Lloyd Donaldson
- Scion, 49 Sala Street, Private Bag 3020, Rotorua 3010, New Zealand
| | - Alankar Vaidya
- Scion, 49 Sala Street, Private Bag 3020, Rotorua 3010, New Zealand
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Takenaka M, Kobayashi T, Inokuma K, Hasunuma T, Maruyama T, Ogino C, Kondo A. Mapping of endoglucanases displayed on yeast cell surface using atomic force microscopy. Colloids Surf B Biointerfaces 2017; 151:134-142. [PMID: 27988474 DOI: 10.1016/j.colsurfb.2016.12.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/14/2016] [Accepted: 12/09/2016] [Indexed: 11/29/2022]
Abstract
The surface of yeast cells has been an attractive interface for the effective use of cellulose. Surface enzymes, however, are difficult to visualize and evaluate. In this study, two kinds of unique anchoring regions were used to display the cellulase, endoglucanase (EG), on a yeast cell surface. Differences in the display level and the localization of EG were observed by atomic force microscopy. By surveying the yeast cell surface with a chemically modified cantilever, the interactive force between the cellulose and EG was measured. Force curve mapping revealed differences in the display levels and the localization of EG according to anchoring regions. The proposed methodology enables visualization of displayed enzymes such as EG on the yeast cell surface.
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Affiliation(s)
- Musashi Takenaka
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Takuya Kobayashi
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Tatsuo Maruyama
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Chiaki Ogino
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
| | - Akihiko Kondo
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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15
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Olsen JP, Borch K, Westh P. Endo/exo-synergism of cellulases increases with substrate conversion. Biotechnol Bioeng 2016; 114:696-700. [PMID: 27617666 DOI: 10.1002/bit.26179] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/01/2016] [Accepted: 09/05/2016] [Indexed: 01/08/2023]
Abstract
Synergy between cellulolytic enzymes is important for their industrial utilization, and numerous studies have addressed the problem of how to optimize the composition of enzyme cocktails with respect to this. The degree of synergy (DS) may change with substrate conversion, and some studies have suggested a maximum in DS early in the process. Here, we systematically investigated interrelationships of DS and conversion in a model system covering a wide range of experimental conditions. The results did not reveal any correlation between DS and contact time, but when plotted against the degree of substrate conversion we saw a systematic increase in DS. We suggest that this is linked to a decreasing reactivity of the substrate. Hence, synergy became increasingly important as the recalcitrance of the remaining substrate grew. Such conversion dependent changes in DS appear to be important both in mechanistic studies and attempts to find industrial enzymes blends with optimal synergy. Biotechnol. Bioeng. 2017;114: 696-700. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Johan Pelck Olsen
- Research Unit for Functional Biomaterials, Department of Science and Environment, Roskilde University, INM, 1 Universitetsvej, Build. 28, DK-4000, Roskilde, Denmark
| | | | - Peter Westh
- Research Unit for Functional Biomaterials, Department of Science and Environment, Roskilde University, INM, 1 Universitetsvej, Build. 28, DK-4000, Roskilde, Denmark
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16
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Pal S, Joy S, Trimukhe KD, Kumbhar PS, Varma AJ, Padmanabhan S. Pretreatment and enzymatic process modification strategies to improve efficiency of sugar production from sugarcane bagasse. 3 Biotech 2016; 6:126. [PMID: 28330198 PMCID: PMC4909031 DOI: 10.1007/s13205-016-0446-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/26/2016] [Indexed: 11/25/2022] Open
Abstract
Pretreatment and enzymatic hydrolysis play a critical role in the economic production of sugars and fuels from lignocellulosic biomass. In this study, we evaluated diverse pilot-scale pretreatments and different post-pretreatment strategies for the production of fermentable sugars from sugarcane bagasse. For the pretreatment of bagasse at pilot-scale level, steam explosion without catalyst and combination of sulfuric and oxalic acids at low and high loadings were used. Subsequently, to enhance the efficiency of enzymatic hydrolysis of the pretreated bagasse, three different post-pretreatment process schemes were investigated. In the first scheme (Scheme 1), enzymatic hydrolysis was conducted on the whole pretreated slurry, without treatments such as washing or solid–liquid separation. In the second scheme (Scheme 2), the pretreated slurry was first pressure filtered to yield a solid and liquid phase. Following filtration, the separated liquid phase was remixed with the solid wet cake to generate slurry, which was then subsequently used for enzymatic hydrolysis. In the third scheme (Scheme 3), the pretreated slurry was washed with more water and filtered to obtain a solid and liquid phase, in which only the former was subjected to enzymatic hydrolysis. A 10 % higher enzymatic conversion was obtained in Scheme 2 than Scheme 1, while Scheme 3 resulted in only a 5–7 % increase due to additional washing unit operation and solid–liquid separation. Dynamic light scattering experiments conducted on post-pretreated bagasse indicate decrease of particle size due to solid–liquid separation involving pressure filtration provided increased the yield of C6 sugars. It is anticipated that different process modification methods used in this study before the enzymatic hydrolysis step can make the overall cellulosic ethanol process effective and possibly cost effective.
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Affiliation(s)
- Siddhartha Pal
- Praj Matrix R&D Center, Urawade, Pune, Maharashtra India
- Department of Technology, Savitribai Phule Pune University, Ganeshkhind, Pune, Maharashtra India
| | - Shereena Joy
- Praj Matrix R&D Center, Urawade, Pune, Maharashtra India
| | - Kalpana D. Trimukhe
- Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune, Maharashtra India
| | - Pramod S. Kumbhar
- Praj Matrix R&D Center, Urawade, Pune, Maharashtra India
- Department of Technology, Savitribai Phule Pune University, Ganeshkhind, Pune, Maharashtra India
| | - Anjani J. Varma
- Department of Technology, Savitribai Phule Pune University, Ganeshkhind, Pune, Maharashtra India
- Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune, Maharashtra India
- Central University of Haryana, Post-Pali District, Mahendergarh, Haryana 123029 India
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17
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Eibinger M, Sigl K, Sattelkow J, Ganner T, Ramoni J, Seiboth B, Plank H, Nidetzky B. Functional characterization of the native swollenin from Trichoderma reesei: study of its possible role as C1 factor of enzymatic lignocellulose conversion. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:178. [PMID: 27570542 PMCID: PMC5000517 DOI: 10.1186/s13068-016-0590-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/15/2016] [Indexed: 05/28/2023]
Abstract
BACKGROUND Through binding to cellulose, expansin-like proteins are thought to loosen the structural order of crystalline surface material, thus making it more accessible for degradation by hydrolytic enzymes. Swollenin SWO1 is the major expansin-like protein from the fungus Trichoderma reesei. Here, we have performed a detailed characterization of a recombinant native form of SWO1 with respect to its possible auxiliary role in the enzymatic saccharification of lignocellulosic substrates. RESULTS The swo1 gene was overexpressed in T. reesei QM9414 Δxyr1 mutant, featuring downregulated cellulase production, and the protein was purified from culture supernatant. SWO1 was N-glycosylated and its circular dichroism spectrum suggested a folded protein. Adsorption isotherms (25 °C, pH 5.0, 1.0 mg substrate/mL) revealed SWO1 to be 120- and 20-fold more specific for binding to birchwood xylan and kraft lignin, respectively, than for binding to Avicel PH-101. The SWO1 binding capacity on lignin (25 µmol/g) exceeded 12-fold that on Avicel PH-101 (2.1 µmol/g). On xylan, not only the binding capacity (22 µmol/g) but also the affinity of SWO1 (K d = 0.08 µM) was enhanced compared to Avicel PH-101 (K d = 0.89 µM). SWO1 caused rapid release of a tiny amount of reducing sugars (<1 % of total) from different substrates (Avicel PH-101, nanocrystalline cellulose, steam-pretreated wheat straw, barley β-glucan, cellotetraose) but did not promote continued saccharification. Atomic force microscopy revealed that amorphous cellulose films were not affected by SWO1. Also with AFM, binding of SWO1 to cellulose nanocrystallites was demonstrated at the single-molecule level, but adsorption did not affect this cellulose. SWO1 exhibited no synergy with T. reesei cellulases in the hydrolysis of the different celluloses. However, SWO1 boosted slightly (1.5-fold) the reducing sugar release from a native grass substrate. CONCLUSIONS SWO1 is a strongly glycosylated protein, which has implications for producing it in heterologous hosts. Although SWO1 binds to crystalline cellulose, its adsorption to xylan is much stronger. SWO1 is not an auxiliary factor of the enzymatic degradation of a variety of cellulosic substrates. Effect of SWO1 on sugar release from intact plant cell walls might be exploitable with certain (e.g., mildly pretreated) lignocellulosic feedstocks.
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Affiliation(s)
- Manuel Eibinger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010 Graz, Austria
| | - Karin Sigl
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, 8010 Graz, Austria
| | - Jürgen Sattelkow
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Thomas Ganner
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Jonas Ramoni
- Research Division Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1A/166, 1060 Vienna, Austria
| | - Bernhard Seiboth
- Research Division Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1A/166, 1060 Vienna, 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, Petersgasse 12/1, 8010 Graz, Austria
- Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
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18
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Wallace J, Brienzo M, García-Aparicio MP, Görgens JF. Lignin enrichment and enzyme deactivation as the root cause of enzymatic hydrolysis slowdown of steam pretreated sugarcane bagasse. N Biotechnol 2016; 33:361-71. [PMID: 26820122 DOI: 10.1016/j.nbt.2016.01.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 11/25/2015] [Accepted: 01/14/2016] [Indexed: 01/21/2023]
Abstract
The enzymatic hydrolysis (EH) rate normally decreases during the hydrolysis, leaving unhydrolyzed material as residue. This phenomenon occurs during the hydrolysis of both cellulose (avicel) and lignocellulosic material, in nature or even pretreated. The progression of EH of steam pretreated sugarcane bagasse was associated with an initial (fast), intermediate (slower) and recalcitrant (slowest) phases, at glucan to glucose conversion yields of 61.7, 81.6 and 86%, respectively. Even though the EH of avicel as a simpler material than steam pretreated sugarcane bagasse, EH slowdown was present. The less thermo-stable endo-xylanase lost 58% of initial enzyme activity, followed by β-glucosidase that lost 16%, culminating in FPase activity loss of 30% in the first 24hours. After 72hours of EH the total loss of FPase activity was 40% compared to the initial activity. Analysis of the solid residue from EH showed that lignin content, phenolic compounds and ash increased while glucan decreased as hydrolysis progressed. During the initial fast phase of EH, the total solid residue surface area consisted predominantly of internal surface area. Thereafter, in the intermediate and recalcitrant phases of EH, the ratio of external:internal surface area increased. The proposed fiber damage and decrease in internal surface area, probably by EH action, was visualized by scanning electron microscopy imagery. The higher lignin/glucan ratio as EH progressed and enzyme deactivation by thermo instability were the main effects observed, respectively to substrate and enzyme.
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Affiliation(s)
- Joshua Wallace
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa
| | - Michel Brienzo
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
| | - María P García-Aparicio
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa; Department of Microbiology, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa
| | - Johann F Görgens
- Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa
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19
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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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20
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Ganner T, Roŝker S, Eibinger M, Kraxner J, Sattelkow J, Rattenberger J, Fitzek H, Chernev B, Grogger W, Nidetzky B, Plank H. Tunable Semicrystalline Thin Film Cellulose Substrate for High-Resolution, In-Situ AFM Characterization of Enzymatic Cellulose Degradation. ACS APPLIED MATERIALS & INTERFACES 2015; 7:27900-27909. [PMID: 26618709 DOI: 10.1021/acsami.5b09948] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In the field of enzymatic cellulose degradation, fundamental interactions between different enzymes and polymorphic cellulose materials are of essential importance but still not understood in full detail. One technology with the potential of direct visualization of such bioprocesses is atomic force microscopy (AFM) due to its capability of real-time in situ investigations with spatial resolutions down to the molecular scale. To exploit the full capabilities of this technology and unravel fundamental enzyme-cellulose bioprocesses, appropriate cellulose substrates are decisive. In this study, we introduce a semicrystalline-thin-film-cellulose (SCFTC) substrate which fulfills the strong demands on such ideal cellulose substrates by means of (1) tunable polymorphism via variable contents of homogeneously sized cellulose nanocrystals embedded in an amorphous cellulose matrix; (2) nanoflat surface topology for high-resolution and high-speed AFM; and (3) fast, simple, and reproducible fabrication. The study starts with a detailed description of SCTFC preparation protocols including an in-depth material characterization. In the second part, we demonstrate the suitability of SCTFC substrates for enzymatic degradation studies by combined, individual, and sequential exposure to TrCel6A/TrCel7A cellulases (Trichoderma reesei) to visualize synergistic effects down to the nanoscale.
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Affiliation(s)
- Thomas Ganner
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology , Steyrergasse 17, A-8010 Graz, Austria
| | - Stephanie Roŝker
- Graz Centre for Electron Microscopy , Steyrergasse 17, A-8010 Graz, Austria
| | - Manuel Eibinger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology , Petersgasse 12, A-8010 Graz, Austria
| | - Johanna Kraxner
- Graz Centre for Electron Microscopy , Steyrergasse 17, A-8010 Graz, Austria
| | - Jürgen Sattelkow
- Graz Centre for Electron Microscopy , Steyrergasse 17, A-8010 Graz, Austria
| | | | - Harald Fitzek
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology , Steyrergasse 17, A-8010 Graz, Austria
| | - Boril Chernev
- Graz Centre for Electron Microscopy , Steyrergasse 17, A-8010 Graz, Austria
| | - Werner Grogger
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology , Steyrergasse 17, A-8010 Graz, Austria
- Graz Centre for Electron Microscopy , Steyrergasse 17, A-8010 Graz, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology , Petersgasse 12, A-8010 Graz, Austria
- Austrian Centre of Industrial Biotechnology , Petersgasse 14, A-8010 Graz, Austria
| | - Harald Plank
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology , Steyrergasse 17, A-8010 Graz, Austria
- Graz Centre for Electron Microscopy , Steyrergasse 17, A-8010 Graz, Austria
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21
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Malinowska KH, Rind T, Verdorfer T, Gaub HE, Nash MA. Quantifying Synergy, Thermostability, and Targeting of Cellulolytic Enzymes and Cellulosomes with Polymerization-Based Amplification. Anal Chem 2015; 87:7133-40. [DOI: 10.1021/acs.analchem.5b00936] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Klara H. Malinowska
- Lehrstuhl für Angewandte
Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, 80799 Munich, Germany
| | - Thomas Rind
- Lehrstuhl für Angewandte
Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, 80799 Munich, Germany
| | - Tobias Verdorfer
- Lehrstuhl für Angewandte
Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, 80799 Munich, Germany
| | - Hermann E. Gaub
- Lehrstuhl für Angewandte
Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, 80799 Munich, Germany
| | - Michael A. Nash
- Lehrstuhl für Angewandte
Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, 80799 Munich, Germany
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22
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Yang D, Parlange JY, Walker LP. Cellulases Significantly Alter the Nano-Scale Reaction Space for Pretreated Lignocellulosic Biomass. Ind Biotechnol (New Rochelle N Y) 2014. [DOI: 10.1089/ind.2014.0028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Dong Yang
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY
| | - Jean-Yves Parlange
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY
| | - Larry P. Walker
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY
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23
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Eibinger M, Ganner T, Bubner P, Rošker S, Kracher D, Haltrich D, Ludwig R, Plank H, Nidetzky B. Cellulose surface degradation by a lytic polysaccharide monooxygenase and its effect on cellulase hydrolytic efficiency. J Biol Chem 2014; 289:35929-38. [PMID: 25361767 PMCID: PMC4276861 DOI: 10.1074/jbc.m114.602227] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lytic polysaccharide monooxygenase (LPMO) represents a unique principle of oxidative degradation of recalcitrant insoluble polysaccharides. Used in combination with hydrolytic enzymes, LPMO appears to constitute a significant factor of the efficiency of enzymatic biomass depolymerization. LPMO activity on different cellulose substrates has been shown from the slow release of oxidized oligosaccharides into solution, but an immediate and direct demonstration of the enzyme action on the cellulose surface is lacking. Specificity of LPMO for degrading ordered crystalline and unordered amorphous cellulose material of the substrate surface is also unknown. We show by fluorescence dye adsorption analyzed with confocal laser scanning microscopy that a LPMO (from Neurospora crassa) introduces carboxyl groups primarily in surface-exposed crystalline areas of the cellulosic substrate. Using time-resolved in situ atomic force microscopy we further demonstrate that cellulose nano-fibrils exposed on the surface are degraded into shorter and thinner insoluble fragments. Also using atomic force microscopy, we show that prior action of LPMO enables cellulases to attack otherwise highly resistant crystalline substrate areas and that it promotes an overall faster and more complete surface degradation. Overall, this study reveals key characteristics of LPMO action on the cellulose surface and suggests the effects of substrate morphology on the synergy between LPMO and hydrolytic enzymes in cellulose depolymerization.
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Affiliation(s)
- Manuel Eibinger
- From the Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria
| | - Thomas Ganner
- Institute of Electron Microscopy and Nanoanalysis and
| | - Patricia Bubner
- From the Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria
| | | | - Daniel Kracher
- Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria, and
| | - Dietmar Haltrich
- Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria, and
| | - Roland Ludwig
- Department of Food Science and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria, and
| | - Harald Plank
- Institute of Electron Microscopy and Nanoanalysis and Graz Centre for Electron Microscopy, Steyrergasse 17, A-8010 Graz, Austria,
| | - Bernd Nidetzky
- From the Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria, Austrian Centre of Industrial Biotechnology, Petersgasse 14, A-8010 Graz, Austria
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24
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Monschein M, Reisinger C, Nidetzky B. Dissecting the effect of chemical additives on the enzymatic hydrolysis of pretreated wheat straw. BIORESOURCE TECHNOLOGY 2014; 169:713-722. [PMID: 25108473 DOI: 10.1016/j.biortech.2014.07.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 07/13/2014] [Accepted: 07/14/2014] [Indexed: 05/24/2023]
Abstract
Chemical additives were examined for ability to increase the enzymatic hydrolysis of thermo-acidically pretreated wheat straw by Trichoderma reesei cellulase at 50 °C. Semi-empirical descriptors derived from the hydrolysis time courses were applied to compare influence of these additives on lignocellulose bioconversion on a kinetic level, presenting a novel view on their mechanism of action. Focus was on rate retardation during hydrolysis, substrate conversion and enzyme adsorption. PEG 8000 enabled a reduction of enzyme loading by 50% while retaining the same conversion of 67% after 24h. For the first time, a beneficial effect of urea is reported, increasing the final substrate conversion after 48 h by 16%. The cationic surfactant cetyl-trimethylammonium bromide (CTAB) enhanced the hydrolysis rate at extended reaction time (rlim) by 34% and reduced reaction time by 28%. A combination of PEG 8000 and urea increased sugar release more than additives used individually.
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Affiliation(s)
- Mareike Monschein
- Austrian Centre of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria
| | - Christoph Reisinger
- CLARIANT Produkte (Deutschland) GmbH, Group Biotechnology, Staffelseestraße 6, 81477 Munich, Germany
| | - Bernd Nidetzky
- Austrian Centre of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria; Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/I, 8010 Graz, Austria.
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