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Leroy A, Fanuel M, Alvarado C, Rogniaux H, Grisel S, Haon M, Berrin JG, Paës G, Guillon F. In situ imaging of LPMO action on plant tissues. Carbohydr Polym 2024; 343:122465. [PMID: 39174080 DOI: 10.1016/j.carbpol.2024.122465] [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] [Received: 04/23/2024] [Revised: 06/20/2024] [Accepted: 07/04/2024] [Indexed: 08/24/2024]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that oxidatively cleave recalcitrant polysaccharides such as cellulose. Several studies have reported LPMO action in synergy with other carbohydrate-active enzymes (CAZymes) for the degradation of lignocellulosic biomass but direct LPMO action at the plant tissue level remains challenging to investigate. Here, we have developed a MALDI-MS imaging workflow to detect oxidised oligosaccharides released by a cellulose-active LPMO at cellular level on maize tissues. Using this workflow, we imaged LPMO action and gained insight into the spatial variation and relative abundance of oxidised and non-oxidised oligosaccharides. We reveal a targeted action of the LPMO related to the composition and organisation of plant cell walls.
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Affiliation(s)
- Amandine Leroy
- INRAE, UR 1268 BIA, 44316 Nantes, France; INRAE, Université de Reims Champagne Ardenne, FARE, UMR A 614, 51100 Reims, France.
| | - Mathieu Fanuel
- INRAE, UR 1268 BIA, 44316 Nantes, France; INRAE, BIBS Facility, 44316 Nantes, France.
| | | | - Hélène Rogniaux
- INRAE, UR 1268 BIA, 44316 Nantes, France; INRAE, BIBS Facility, 44316 Nantes, France.
| | - Sacha Grisel
- INRAE, Aix Marseille Université, Biodiversité et Biotechnologie Fongiques (BBF), 13009 Marseille, France; INRAE, Aix Marseille Université, 3PE platform, 13009 Marseille, France.
| | - Mireille Haon
- INRAE, Aix Marseille Université, Biodiversité et Biotechnologie Fongiques (BBF), 13009 Marseille, France; INRAE, Aix Marseille Université, 3PE platform, 13009 Marseille, France.
| | - Jean-Guy Berrin
- INRAE, Aix Marseille Université, Biodiversité et Biotechnologie Fongiques (BBF), 13009 Marseille, France.
| | - Gabriel Paës
- INRAE, Université de Reims Champagne Ardenne, FARE, UMR A 614, 51100 Reims, France.
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2
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Forsberg Z, Tuveng TR, Eijsink VGH. A modular enzyme with combined hemicellulose-removing and LPMO activity increases cellulose accessibility in softwood. FEBS J 2024. [PMID: 39190632 DOI: 10.1111/febs.17250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 07/05/2024] [Accepted: 08/13/2024] [Indexed: 08/29/2024]
Abstract
Because of the association with other complex polysaccharides, extracting and utilizing cellulose from lignocellulosic materials requires the combined action of a broad range of carbohydrate-active enzymes, including multiple glycoside hydrolases (GHs) and lytic polysaccharide monooxygenases (LPMOs). The interplay between these enzymes and the way in which Nature orchestrates their co-existence and combined action are topics of great scientific and industrial interest. To gain more insight into these issues, we have studied the lignocellulose-degrading abilities of an enzyme from Caldibacillus cellulovorans (CcLPMO10-Man5), comprising an LPMO domain, a GH5 mannanase domain and two family 3 carbohydrate-binding modules (CBM3). Using a natural softwood substrate, we show that this enzyme promotes cellulase activity, i.e., saccharification of cellulose, both by removing mannan covering the cellulose and by oxidatively breaking up the cellulose structure. Synergy with CcLPMO10-Man5 was most pronounced for two tested cellobiohydrolases, whereas effects were smaller for a tested endoglucanase, which is in line with the notion that cellobiohydrolases and LPMOs attack the same crystalline regions of the cellulose, whereas endoglucanases attack semi-crystalline and amorphous regions. Importantly, the LPMO domain of CcLPMO10-Man5 is incapable of accessing the softwood cellulose in absence of the mannanase domain. Considering that LPMOs not bound to a substrate are sensitive to autocatalytic inactivation, this intramolecular synergy provides a perfect rationale for the evolution of modular enzymes such as CcLPMO10-Man5. The intramolecular coupling of the LPMO with a mannanase and two CBMs ensures that the LPMO is directed to areas where mannans are removed and cellulose thus becomes available.
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Affiliation(s)
- Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Tina R Tuveng
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
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3
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Angeltveit CF, Várnai A, Eijsink VGH, Horn SJ. Enhancing enzymatic saccharification yields of cellulose at high solid loadings by combining different LPMO activities. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:39. [PMID: 38461298 PMCID: PMC10924376 DOI: 10.1186/s13068-024-02485-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 02/24/2024] [Indexed: 03/11/2024]
Abstract
BACKGROUND The polysaccharides in lignocellulosic biomass hold potential for production of biofuels and biochemicals. However, achieving efficient conversion of this resource into fermentable sugars faces challenges, especially when operating at industrially relevant high solid loadings. While it is clear that combining classical hydrolytic enzymes and lytic polysaccharide monooxygenases (LPMOs) is necessary to achieve high saccharification yields, exactly how these enzymes synergize at high solid loadings remains unclear. RESULTS An LPMO-poor cellulase cocktail, Celluclast 1.5 L, was spiked with one or both of two fungal LPMOs from Thermothielavioides terrestris and Thermoascus aurantiacus, TtAA9E and TaAA9A, respectively, to assess their impact on cellulose saccharification efficiency at high dry matter loading, using Avicel and steam-exploded wheat straw as substrates. The results demonstrate that LPMOs can mitigate the reduction in saccharification efficiency associated with high dry matter contents. The positive effect of LPMO inclusion depends on the type of feedstock and the type of LPMO and increases with the increasing dry matter content and reaction time. Furthermore, our results show that chelating free copper, which may leak out of the active site of inactivated LPMOs during saccharification, with EDTA prevents side reactions with in situ generated H2O2 and the reductant (ascorbic acid). CONCLUSIONS This study shows that sustaining LPMO activity is vital for efficient cellulose solubilization at high substrate loadings. LPMO cleavage of cellulose at high dry matter loadings results in new chain ends and thus increased water accessibility leading to decrystallization of the substrate, all factors making the substrate more accessible to cellulase action. Additionally, this work highlights the importance of preventing LPMO inactivation and its potential detrimental impact on all enzymes in the reaction.
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Affiliation(s)
- Camilla F Angeltveit
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
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4
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Chen K, Zhao X, Zhang P, Long L, Ding S. A novel AA14 LPMO from Talaromyces rugulosus with bifunctional cellulolytic/hemicellulolytic activity boosted cellulose hydrolysis. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:30. [PMID: 38395898 PMCID: PMC10885436 DOI: 10.1186/s13068-024-02474-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 02/10/2024] [Indexed: 02/25/2024]
Abstract
BACKGROUND The recently discovered PcAA14A and B from white-rot basidiomycete Pycnoporus coccineus enriched our understanding of the oxidative degradation of xylan in fungi, however, the unusual mode of action of AA14 LPMOs has sparked controversy. The substrate specificity and functionality of AA14 LPMOs still remain enigmatic and need further investigation. RESULTS In this study, a novel AA14 LPMO was characterized from the ascomycete Talaromyces rugulosus. TrAA14A has a broad substrate specificity with strong oxidative activity on pure amorphous cellulose and xyloglucan. It could simultaneously oxidize cellulose, xylan and xyloglucan in natural hemi/cellulosic substrate such as fibrillated eucalyptus pulp, and released native and oxidized cello-oligosaccharides, xylo-oligosaccharides and xyloglucan oligosaccharides from this substrate, but its cellulolytic/hemicellulolytic activity became weaker as the contents of xylan increase in the alkaline-extracted hemi/cellulosic substrates. The dual cellulolytic/hemicellulolytic activity enables TrAA14A to possess a profound boosting effect on cellulose hydrolysis by cellulolytic enzymes. Structure modelling of TrAA14A revealed that it exhibits a relatively flat active-site surface similar to the active-site surfaces in AA9 LPMOs but quite distinct from PcAA14B, despite TrAA14A is strongly clustered together with AA14 LPMOs. Remarkable difference in electrostatic potentials of L2 and L3 surfaces was also observed among TrAA14A, PcAA14B and NcLPMO9F. We speculated that the unique feature in substrate-binding surface might contribute to the cellulolytic/hemicellulolytic activity of TrAA14A. CONCLUSIONS The extensive cellulolytic/hemicellulolytic activity on natural hemi/cellulosic substrate indicated that TrAA14A from ascomycete is distinctively different from previously characterized xylan-active AA9 or AA14 LPMOs. It may play as a bifunctional enzyme to decompose some specific network structures formed between cellulose and hemicellulose in the plant cell walls. Our findings shed new insights into the novel substrate specificities and biological functionalities of AA14 LPMOs, and will contribute to developing novel bifunctional LPMOs as the booster in commercial cellulase cocktails to efficiently break down the hemicellulose-cellulose matrix in lignocellulose.
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Affiliation(s)
- Kaixiang Chen
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Xu Zhao
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Peiyu Zhang
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Liangkun Long
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Shaojun Ding
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
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5
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Nousi A, Molina GA, Schiano-di-Cola C, Sørensen TH, Borch K, Pedersen JN, Westh P, Marie R. Impact of Synergy Partner Cel7B on Cel7A Binding Rates: Insights from Single-Molecule Data. J Phys Chem B 2024; 128:635-647. [PMID: 38227769 PMCID: PMC10824242 DOI: 10.1021/acs.jpcb.3c05697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/18/2024]
Abstract
Enzymatic degradation of cellulosic biomass is a well-established route for the sustainable production of biofuels, chemicals, and materials. A strategy employed by nature and industry to achieve an efficient degradation of cellulose is that cellobiohydrolases (or exocellulases), such as Cel7A, work synergistically with endoglucanases, such as Cel7B, to achieve the complete degradation of cellulose. However, a complete mechanistic understanding of this exo-endo synergy is still lacking. Here, we used single-molecule fluorescence microscopy to quantify the binding kinetics of Cel7A on cellulose when it is acting alone on the cellulose fibrils and in the presence of its synergy partner, the endoglucanase Cel7B. To this end, we used a fluorescently tagged Cel7A and studied its binding in the presence of the unlabeled Cel7B. This provided the single-molecule data necessary for the estimation of the rate constants of association kON and dissociation kOFF of Cel7A for the substrate. We show that the presence of Cel7B does not impact the dissociation rate constant, kOFF. But, the association rate of Cel7A decreases by a factor of 2 when Cel7B is present at a molar proportion of 10:1. This ratio has previously been shown to lead to synergy. This decrease in association rate is observed in a wide range of total enzyme concentrations, from sub nM to μM concentrations. This decrease in kON is consistent with the formation of cellulase clusters recently observed by others using atomic force microscopy.
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Affiliation(s)
- Aimilia Nousi
- Department
of Health Technology, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
| | - Gustavo Avelar Molina
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, 2800 Kongens Lyngby, Denmark
- The
Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | | | | | - Kim Borch
- Novozymes
A/S, Krogshøjvej
36, 2880 Bagsværd, Denmark
| | - Jonas N. Pedersen
- Department
of Health Technology, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
| | - Peter Westh
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Rodolphe Marie
- Department
of Health Technology, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
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6
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Paudel L, Pardhe BD, Han SR, Lee JH, Oh TJ. Identification and evaluation of CAZyme genes, along with functional characterization of a new GH46 chitosanase from Streptomyces sp. KCCM12257. Int J Biol Macromol 2023; 253:127457. [PMID: 37844821 DOI: 10.1016/j.ijbiomac.2023.127457] [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] [Received: 07/30/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
The genomic analysis of Streptomyces sp. KCCM12257 presented 233 CAZyme genes with a predominant glycosyl hydrolase family. This contributes degradation of various polysaccharides including chitin and chitosan, and other promising candidates for the production of different oligosaccharides. We screened the strain providing different polysaccharides as a sole source of carbon and strain KCCM12257, showed higher activity towards colloidal chitosan. Further, we identified and characterized a new chitosanase (MDI5907146) of GH46 family. There was no activity towards chitin, carboxymethylcellulose, or even with chitosan powder. This enzyme acts on colloidal chitosan and hydrolyzes it down into monoacetyl chitobiose, which consists of two glucosamine units with an acetyl group attached to them. The maximum enzyme activity was observed at pH 6.5 and 40 °C using colloidal chitosan as a substrate. The Co2+ metal ions almost double the reaction as compared to other metal ions. The dissociation constant (Km) and of colloidal chitosan (≥90 % and ≥75%DD) were 3.03 mg/ml and 5.01 mg/ml respectively, while maximum velocity (Vmax) values were found to be 36 mg/ml, and 30 μM/μg/min, respectively. Similarly, catalytic efficiency (Kcat/Km) of colloidal chitosan with ≥90 %DD was 1.9 fold higher than colloidal chitosan with ≥75%DD.
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Affiliation(s)
- Lakshan Paudel
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea
| | - Bashu Dev Pardhe
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea
| | - So-Ra Han
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea; Genome-based BioIT Convergence Institute, Asan 31460, Republic of Korea; Bio Big Data-based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, Republic of Korea
| | - Jun Hyuck Lee
- Research Unit of Cryogenic Novel Materials, Korea Polar Research Institute, Incheon 21990, Republic of Korea.
| | - Tae-Jin Oh
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, Republic of Korea; Genome-based BioIT Convergence Institute, Asan 31460, Republic of Korea; Bio Big Data-based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, Republic of Korea; Department of Pharmaceutical Engineering and Biotechnology, SunMoon University, Asan 31460, Republic of Korea.
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7
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Angeltveit CF, Jeoh T, Horn SJ. Lytic polysaccharide monooxygenase activity increases productive binding capacity of cellobiohydrolases on cellulose. BIORESOURCE TECHNOLOGY 2023; 389:129806. [PMID: 37769978 DOI: 10.1016/j.biortech.2023.129806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Cellobiohydrolases are crucial for cellulose breakdown, but their efficiency on crystalline cellulose is hampered by limited access to single chain ends to initiate hydrolysis. As a result, they depend on enzymes like lytic polysaccharide monooxygenases (LPMOs), which directly target the crystalline cellulose surface. This study investigated how LPMO pretreatment affected the productive binding capacity of a Trichoderma longibrachiatum cellobiohydrolase, TlCBHI, on crystalline cellulose by applying an amperometric cellobiose dehydrogenase biosensor. After the 24-hour of LPMO pretreatment, the productive binding capacity of TlCBHI significantly increased in all reactions. However, with a shorter 5-hour LPMO pretreatment, minimal to no effect on productive binding capacity was observed. Of note, all LPMO reactions were inactivated around this time point. This delayed LPMO effect suggests that the improved binding capacity for cellulases does not directly result from cellulose chain cleavage by LPMOs but rather from the cellulose decrystallization following the oxidative cleavage.
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Affiliation(s)
- Camilla F Angeltveit
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Tina Jeoh
- Biological and Agricultural Engineering, University of California, Davis, United States
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
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8
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Yao RA, Reyre JL, Tamburrini KC, Haon M, Tranquet O, Nalubothula A, Mukherjee S, Le Gall S, Grisel S, Longhi S, Madhuprakash J, Bissaro B, Berrin JG. The Ustilago maydis AA10 LPMO is active on fungal cell wall chitin. Appl Environ Microbiol 2023; 89:e0057323. [PMID: 37702503 PMCID: PMC10617569 DOI: 10.1128/aem.00573-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/14/2023] [Indexed: 09/14/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) can perform oxidative cleavage of glycosidic bonds in carbohydrate polymers (e.g., cellulose, chitin), making them more accessible to hydrolytic enzymes. While most studies have so far mainly explored the role of LPMOs in a (plant) biomass conversion context, alternative roles and paradigms begin to emerge. The AA10 LPMOs are active on chitin and/or cellulose and mostly found in bacteria and in some viruses and archaea. Interestingly, AA10-encoding genes are also encountered in some pathogenic fungi of the Ustilaginomycetes class, such as Ustilago maydis, responsible for corn smut disease. Transcriptomic studies have shown the overexpression of the AA10 gene during the infectious cycle of U. maydis. In fact, U. maydis has a unique AA10 gene that codes for a catalytic domain appended with a C-terminal disordered region. To date, there is no public report on fungal AA10 LPMOs. In this study, we successfully produced the catalytic domain of this LPMO (UmAA10_cd) in Pichia pastoris and carried out its biochemical characterization. Our results show that UmAA10_cd oxidatively cleaves α- and β-chitin with C1 regioselectivity and boosts chitin hydrolysis by a GH18 chitinase from U. maydis (UmGH18A). Using a biologically relevant substrate, we show that UmAA10_cd exhibits enzymatic activity on U. maydis fungal cell wall chitin and promotes its hydrolysis by UmGH18A. These results represent an important step toward the understanding of the role of LPMOs in the fungal cell wall remodeling process during the fungal life cycle.IMPORTANCELytic polysaccharide monooxygenases (LPMOs) have been mainly studied in a biotechnological context for the efficient degradation of recalcitrant polysaccharides. Only recently, alternative roles and paradigms begin to emerge. In this study, we provide evidence that the AA10 LPMO from the phytopathogen Ustilago maydis is active against fungal cell wall chitin. Given that chitin-active LPMOs are commonly found in microbes, it is important to consider fungal cell wall as a potential target for this enigmatic class of enzymes.
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Affiliation(s)
- Roseline Assiah Yao
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
| | - Jean-Lou Reyre
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
- IFP Energies Nouvelles, Rueil-Malmaison, France
| | - Ketty C. Tamburrini
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
- CNRS, Aix Marseille Univ, UMR 7257 Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Mireille Haon
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
- INRAE, Aix Marseille Univ, 3PE Platform, Marseille, France
| | - Olivier Tranquet
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
| | - Akshay Nalubothula
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Saumashish Mukherjee
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Sophie Le Gall
- INRAE, UR1268 BIA, Nantes, France
- INRAE, PROBE Research Infrastructure, BIBS Facility, Nantes, France
| | - Sacha Grisel
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
- INRAE, Aix Marseille Univ, 3PE Platform, Marseille, France
| | - Sonia Longhi
- CNRS, Aix Marseille Univ, UMR 7257 Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Jogi Madhuprakash
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India
| | - Bastien Bissaro
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
| | - Jean-Guy Berrin
- INRAE, Aix Marseille Univ, UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), Marseille, France
- INRAE, Aix Marseille Univ, 3PE Platform, Marseille, France
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9
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Grace Barrios-Gutiérrez S, Inés Vélez-Mercado M, Rodrigues Ortega J, da Silva Lima A, Luiza da Rocha Fortes Saraiva A, Leila Berto G, Segato F. Oxidative Machinery of basidiomycetes as potential enhancers in lignocellulosic biorefineries: A lytic polysaccharide monooxygenases approach. BIORESOURCE TECHNOLOGY 2023; 386:129481. [PMID: 37437815 DOI: 10.1016/j.biortech.2023.129481] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/05/2023] [Accepted: 07/08/2023] [Indexed: 07/14/2023]
Abstract
Basidiomycetes are renowned as highly effective decomposers of plant materials, due to their extensive array of oxidative enzymes, which enable them to efficiently break down complex lignocellulosic biomass structures. Among the oxidative machinery of industrially relevant basidiomycetes, the role of lytic polysaccharide monooxygenases (LPMO) in lignocellulosic biomass deconstruction is highlighted. So far, only a limited number of basidiomycetes LPMOs have been identified and heterologously expressed. These LPMOs have presented activity on cellulose and hemicellulose, as well as participation in the deconstruction of lignin. Expanding on this, the current review proposes both enzymatic and non-enzymatic mechanisms of LPMOs for biomass conversion, considering the significance of the Carbohydrate-Binding Modules and other C-terminal regions domains associated with their structure, which is involved in the deconstruction of lignocellulosic biomass.
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Affiliation(s)
- Solange Grace Barrios-Gutiérrez
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil
| | - Martha Inés Vélez-Mercado
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil
| | - Júlia Rodrigues Ortega
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil
| | - Awana da Silva Lima
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil
| | - Ana Luiza da Rocha Fortes Saraiva
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil
| | - Gabriela Leila Berto
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil
| | - Fernando Segato
- Synthetic and Molecular Biology Laboratory (SyMB), Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, São Paulo, Brazil.
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10
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Gonçalves AL, Cunha PM, da Silva Lima A, Dos Santos JC, Segato F. Production of recombinant lytic polysaccharide monooxygenases and evaluation effect of its addition into Aspergillus fumigatus var. niveus cocktail for sugarcane bagasse saccharification. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140919. [PMID: 37164048 DOI: 10.1016/j.bbapap.2023.140919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/01/2023] [Accepted: 05/03/2023] [Indexed: 05/12/2023]
Abstract
Lignocellulosic biomass is a promising alternative for producing biofuels, despite its recalcitrant nature. There are microorganisms in nature capable of efficiently degrade biomass, such as the filamentous fungi. Among them, Aspergillus fumigatus var. niveus (AFUMN) has a wide variety of carbohydrate-active enzymes (CAZymes), especially hydrolases, but a low number of oxidative enzymes in its genome. To confirm the enzymatic profile of this fungus, this study analyzed the secretome of AFUMN cultured in sugarcane bagasse as the sole carbon source. As expected, the secretome showed a predominance of hydrolytic enzymes compared to oxidative activity. However, it is known that hydrolytic enzymes act in synergy with oxidative proteins to efficiently degrade cellulose polymer, such as the Lytic Polysaccharide Monooxygenases (LPMOs). Thus, three LPMOs from the fungus Thermothelomyces thermophilus (TtLPMO9D, TtLPMO9H, and TtLPMO9O) were selected, heterologous expressed in Aspergillus nidulans, purified, and used to supplement the AFUMN secretome to evaluate their effect on the saccharification of sugarcane bagasse. The saccharification assay was carried out using different concentrations of AFUMN secretome supplemented with recombinant T. thermophilus LPMOs, as well as ascorbic acid as reducing agent for oxidative enzymes. Through a statistic design created by Design-Expert software, we were able to analyze a possible cooperative effect between these components. The results indicated that, in general, the addition of TtLPMO9D and ascorbic acid did not favor the conversion process in this study, while TtLPMO9O had a highly significant cooperative effect in bagasse saccharification compared to the control using only AFUMN secretome.
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Affiliation(s)
- Aline Larissa Gonçalves
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Paula Macedo Cunha
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Awana da Silva Lima
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Júlio César Dos Santos
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil
| | - Fernando Segato
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, SP, Brazil.
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11
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Chemin M, Kansou K, Cahier K, Grellier M, Grisel S, Novales B, Moreau C, Villares A, Berrin JG, Cathala B. Optimized Lytic Polysaccharide Monooxygenase Action Increases Fiber Accessibility and Fibrillation by Releasing Tension Stress in Cellulose Cotton Fibers. Biomacromolecules 2023. [PMID: 37327397 DOI: 10.1021/acs.biomac.3c00303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Lytic polysaccharide monooxygenase (LPMO) enzymes have recently shaken up our knowledge of the enzymatic degradation of biopolymers and cellulose in particular. This unique class of metalloenzymes cleaves cellulose and other recalcitrant polysaccharides using an oxidative mechanism. Despite their potential in biomass saccharification and cellulose fibrillation, the detailed mode of action of LPMOs at the surface of cellulose fibers still remains poorly understood and highly challenging to investigate. In this study, we first determined the optimal parameters (temperature, pH, enzyme concentration, and pulp consistency) of LPMO action on the cellulose fibers by analyzing the changes in molar mass distribution of solubilized fibers using high performance size exclusion chromatography (HPSEC). Using an experimental design approach with a fungal LPMO from the AA9 family (PaLPMO9H) and cotton fibers, we revealed a maximum decrease in molar mass at 26.6 °C and pH 5.5, with 1.6% w/w enzyme loading in dilute cellulose dispersions (100 mg of cellulose at 0.5% w/v). These optimal conditions were used to further investigate the effect of PaLPMO9H on the cellulosic fiber structure. Direct visualization of the fiber surface by scanning electron microscopy (SEM) revealed that PaLPMO9H created cracks on the cellulose surface while it attacked tension regions that triggered the rearrangement of cellulose chains. Solid-state NMR indicated that PaLPMO9H increased the lateral fibril dimension and created novel accessible surfaces. This study confirms the LPMO-driven disruption of cellulose fibers and extends our knowledge of the mechanism underlying such modifications. We hypothesize that the oxidative cleavage at the surface of the fibers releases the tension stress with loosening of the fiber structure and peeling of the surface, thereby increasing the accessibility and facilitating fibrillation.
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Affiliation(s)
| | | | | | | | - Sacha Grisel
- INRAE, Aix Marseille Univ., UMR BBF, F-13009 Marseille, France
- INRAE, Aix Marseille Univ., 3PE platform, F-13009 Marseille, France
| | - Bruno Novales
- INRAE, BIBS Facility, PROBE Infrastructure, F-44316 Nantes, France
| | | | | | - Jean-Guy Berrin
- INRAE, Aix Marseille Univ., UMR BBF, F-13009 Marseille, France
- INRAE, Aix Marseille Univ., 3PE platform, F-13009 Marseille, France
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12
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Qin X, Yang K, Zou J, Wang X, Tu T, Wang Y, Su X, Yao B, Huang H, Luo H. Heterologous expression and characterization of novel GH12 β-glucanase and AA10 lytic polysaccharide monooxygenase from Streptomyces megaspores and their synergistic action in cellulose saccharification. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:89. [PMID: 37221623 DOI: 10.1186/s13068-023-02332-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 04/27/2023] [Indexed: 05/25/2023]
Abstract
BACKGROUND The combination of cellulase and lytic polysaccharide monooxygenase (LPMO) is known to boost enzymatic saccharification of cellulose. Although the synergy between cellulases (GH5, 6 or 7) and LPMOs (AA9) has been extensively studied, the interplay between other glycoside hydrolase and LPMO families remains poorly understood. RESULTS In this study, two cellulolytic enzyme-encoding genes SmBglu12A and SmLpmo10A from Streptomyces megaspores were identified and heterologously expressed in Escherichia coli. The recombinant SmBglu12A is a non-typical endo-β-1,4-glucanase that preferentially hydrolyzed β-1,3-1,4-glucans and slightly hydrolyzed β-1,4-glucans and belongs to GH12 family. The recombinant SmLpmo10A belongs to a C1-oxidizing cellulose-active LPMO that catalyzed the oxidation of phosphoric acid swollen cellulose to produce celloaldonic acids. Moreover, individual SmBglu12A and SmLpmo10A were both active on barley β-1,3-1,4-glucan, lichenan, sodium carboxymethyl cellulose, phosphoric acid swollen cellulose, as well as Avicel. Furthermore, the combination of SmBglu12A and SmLpmo10A enhanced enzymatic saccharification of phosphoric acid swollen cellulose by improving the native and oxidized cello-oligosaccharides yields. CONCLUSIONS These results proved for the first time that the AA10 LPMO was able to boost the catalytic efficiency of GH12 glycoside hydrolases on cellulosic substrates, providing another novel combination of glycoside hydrolase and LPMO for cellulose enzymatic saccharification.
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Affiliation(s)
- Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Kun Yang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiahuan Zou
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
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13
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Qin X, Yang K, Wang X, Tu T, Wang Y, Zhang J, Su X, Yao B, Huang H, Luo H. Insights into the H 2O 2-Driven Lytic Polysaccharide Monooxygenase Activity on Efficient Cellulose Degradation in the White Rot Fungus Irpex lacteus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:8104-8111. [PMID: 37204864 DOI: 10.1021/acs.jafc.3c01777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In contrast to O2, H2O2 as the cosubstrate for lytic polysaccharide monooxygenases (LPMOs) exhibits great advantages in industrial settings for cellulose degradation. However, H2O2-driven LPMO reactions from natural microorganisms have not been fully explored and understood. Herein, secretome analysis unraveled the H2O2-driven LPMO reaction in the efficient lignocellulose-degrading fungus Irpex lacteus, including LPMOs with different oxidative regioselectivities and various H2O2-generating oxidases. Biochemical characterization of H2O2-driven LPMO catalysis showed orders of magnitude improvement in catalytic efficiency compared to that of O2-driven LPMO catalysis for cellulose degradation. Significantly, H2O2 tolerance of LPMO catalysis in I. lacteus was an order of magnitude higher than that in other filamentous fungi. In addition, natural reductants, gallic acid, in particular, presented in lignocellulosic biomass could sufficiently maintain LPMO catalytic reactions. Moreover, the H2O2-driven LPMO catalysis exhibited synergy with canonical endoglucanases for efficient cellulose degradation. Taken together, these findings demonstrate the great application potential of the H2O2-driven LPMO catalysis for upgrading cellulase cocktails to further improve cellulose degradation efficiency.
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Affiliation(s)
- Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kun Yang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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14
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Berhe MH, Song X, Yao L. Improving the Enzymatic Activity and Stability of a Lytic Polysaccharide Monooxygenase. Int J Mol Sci 2023; 24:ijms24108963. [PMID: 37240310 DOI: 10.3390/ijms24108963] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Lytic Polysaccharide Monooxygenases (LPMOs) are copper-dependent enzymes that play a pivotal role in the enzymatic conversion of the most recalcitrant polysaccharides, such as cellulose and chitin. Hence, protein engineering is highly required to enhance their catalytic efficiencies. To this effect, we optimized the protein sequence encoding for an LPMO from Bacillus amyloliquefaciens (BaLPMO10A) using the sequence consensus method. Enzyme activity was determined using the chromogenic substrate 2,6-Dimethoxyphenol (2,6-DMP). Compared with the wild type (WT), the variants exhibit up to a 93.7% increase in activity against 2,6-DMP. We also showed that BaLPMO10A can hydrolyze p-nitrophenyl-β-D-cellobioside (PNPC), carboxymethylcellulose (CMC), and phosphoric acid-swollen cellulose (PASC). In addition to this, we investigated the degradation potential of BaLPMO10A against various substrates such as PASC, filter paper (FP), and Avicel, in synergy with the commercial cellulase, and it showed up to 2.7-, 2.0- and 1.9-fold increases in production with the substrates PASC, FP, and Avicel, respectively, compared to cellulase alone. Moreover, we examined the thermostability of BaLPMO10A. The mutants exhibited enhanced thermostability with an apparent melting temperature increase of up to 7.5 °C compared to the WT. The engineered BaLPMO10A with higher activity and thermal stability provides a better tool for cellulose depolymerization.
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Affiliation(s)
- Miesho Hadush Berhe
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Department of Biotechnology, College of Natural and Computational Sciences, Aksum University, Axum 1010, Ethiopia
| | - Xiangfei Song
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
| | - Lishan Yao
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
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15
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Khamassi A, Dumon C. Enzyme synergy for plant cell wall polysaccharide degradation. Essays Biochem 2023; 67:521-531. [PMID: 37067158 DOI: 10.1042/ebc20220166] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/17/2023] [Accepted: 03/07/2023] [Indexed: 04/18/2023]
Abstract
Valorizing plant cell wall, marine and algal polysaccharides is of utmost importance for the development of the circular bioeconomy. This is because polysaccharides are by far the most abundant organic molecules found in nature with complex chemical structures that require a large set of enzymes for their degradation. Microorganisms produce polysaccharide-specific enzymes that act in synergy when performing hydrolysis. Although discovered since decades enzyme synergy is still poorly understood at the molecular level and thus it is difficult to harness and optimize. In the last few years, more attention has been given to improve and characterize enzyme synergy for polysaccharide valorization. In this review, we summarize literature to provide an overview of the different type of synergy involving carbohydrate modifying enzymes and the recent advances in the field exemplified by plant cell-wall degradation.
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Affiliation(s)
- Ahmed Khamassi
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Claire Dumon
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
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16
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Ipsen JØ, Johansen KS, Brander S. A fast, sensitive and fluorescent LPMO activity assay. Front Microbiol 2023; 14:1128470. [PMID: 36998406 PMCID: PMC10043361 DOI: 10.3389/fmicb.2023.1128470] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/21/2023] [Indexed: 03/16/2023] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are industrially relevant enzymes that utilize a copper co-factor and an oxygen species to break down recalcitrant polysaccharides. These enzymes are secreted by microorganisms and are used in lignocellulosic refineries. As such, they are interesting from both the ecological/biological and industrial perspectives. Here we describe the development of a new fluorescence-based kinetic LPMO activity assay. The assay is based on the enzymatic production of fluorescein from its reduced counterpart. The assay can detect as little as 1 nM LPMO with optimized assay conditions. Furthermore, the reduced fluorescein substrate can also be used to identify peroxidase activity as seen by the formation of fluorescein by horseradish peroxidase. The assay was shown to work well at relatively low H2O2 and dehydroascorbate concentrations. The applicability of the assay was demonstrated.
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Affiliation(s)
| | | | - Søren Brander
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
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17
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The interplay between lytic polysaccharide monooxygenases and glycoside hydrolases. Essays Biochem 2023; 67:551-559. [PMID: 36876880 DOI: 10.1042/ebc20220156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 03/07/2023]
Abstract
In nature, enzymatic degradation of recalcitrant polysaccharides such as chitin and cellulose takes place by a synergistic interaction between glycoside hydrolases (GHs) and lytic polysaccharide monooxygenases (LPMOs). The two different families of carbohydrate-active enzymes use two different mechanisms when breaking glycosidic bonds between sugar moieties. GHs employ a hydrolytic activity and LPMOs are oxidative. Consequently, the topologies of the active sites differ dramatically. GHs have tunnels or clefts lined with a sheet of aromatic amino acid residues accommodating single polymer chains being threaded into the active site. LPMOs are adapted to bind to the flat crystalline surfaces of chitin and cellulose. It is believed that the LPMO oxidative mechanism provides new chain ends that the GHs can attach to and degrade, often in a processive manner. Indeed, there are many reports of synergies as well as rate enhancements when LPMOs are applied in concert with GHs. Still, these enhancements vary in magnitude with respect to the nature of the GH and the LPMO. Moreover, impediment of GH catalysis is also observed. In the present review, we discuss central works where the interplay between LPMOs and GHs has been studied and comment on future challenges to be addressed to fully use the potential of this interplay to improve enzymatic polysaccharide degradation.
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18
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Chaudhari YB, Várnai A, Sørlie M, Horn SJ, Eijsink VGH. Engineering cellulases for conversion of lignocellulosic biomass. Protein Eng Des Sel 2023; 36:gzad002. [PMID: 36892404 PMCID: PMC10394125 DOI: 10.1093/protein/gzad002] [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: 10/28/2022] [Revised: 02/13/2023] [Accepted: 02/24/2023] [Indexed: 03/10/2023] Open
Abstract
Lignocellulosic biomass is a renewable source of energy, chemicals and materials. Many applications of this resource require the depolymerization of one or more of its polymeric constituents. Efficient enzymatic depolymerization of cellulose to glucose by cellulases and accessory enzymes such as lytic polysaccharide monooxygenases is a prerequisite for economically viable exploitation of this biomass. Microbes produce a remarkably diverse range of cellulases, which consist of glycoside hydrolase (GH) catalytic domains and, although not in all cases, substrate-binding carbohydrate-binding modules (CBMs). As enzymes are a considerable cost factor, there is great interest in finding or engineering improved and robust cellulases, with higher activity and stability, easy expression, and minimal product inhibition. This review addresses relevant engineering targets for cellulases, discusses a few notable cellulase engineering studies of the past decades and provides an overview of recent work in the field.
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Affiliation(s)
- Yogesh B Chaudhari
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Morten Sørlie
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology, and Food Science, NMBU-Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
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19
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Guo H, Zhao Y, Chang JS, Lee DJ. Enzymes and enzymatic mechanisms in enzymatic degradation of lignocellulosic biomass: A mini-review. BIORESOURCE TECHNOLOGY 2023; 367:128252. [PMID: 36334864 DOI: 10.1016/j.biortech.2022.128252] [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: 09/29/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Enzymatic hydrolysis is the key step limiting the efficiency of the biorefinery of lignocellulosic biomass. Enzymes involved in enzymatic hydrolysis and their interactions with biomass should be comprehended to form the basis for looking for strategies to improve process efficiency. This article updates the contemporary research on the properties of key enzymes in the lignocellulose biorefinery and their interactions with biomass, adsorption, and hydrolysis. The advanced analytical techniques to track the interactions for exploiting mechanisms are discussed. The challenges and prospects for future research are outlined.
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Affiliation(s)
- Hongliang Guo
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Ying Zhao
- College of Forestry, Northeast Forestry University, Harbin 150040, China
| | - Jo-Shu Chang
- Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung 407, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan; Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-li 32003, Taiwan.
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20
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Uchiyama T, Uchihashi T, Ishida T, Nakamura A, Vermaas JV, Crowley MF, Samejima M, Beckham GT, Igarashi K. Lytic polysaccharide monooxygenase increases cellobiohydrolases activity by promoting decrystallization of cellulose surface. SCIENCE ADVANCES 2022; 8:eade5155. [PMID: 36563138 PMCID: PMC9788756 DOI: 10.1126/sciadv.ade5155] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/21/2022] [Indexed: 05/31/2023]
Abstract
Efficient depolymerization of crystalline cellulose requires cooperation between multiple cellulolytic enzymes. Through biochemical approaches, molecular dynamics (MD) simulation, and single-molecule observations using high-speed atomic force microscopy (HS-AFM), we quantify and track synergistic activity for cellobiohydrolases (CBHs) with a lytic polysaccharide monooxygenase (LPMO) from Phanerochaete chrysosporium. Increasing concentrations of LPMO (AA9D) increased the activity of a glycoside hydrolase family 6 CBH, Cel6A, whereas the activity of a family 7 CBH (Cel7D) was enhanced only at lower concentrations of AA9D. MD simulation suggests that the result of AA9D action to produce chain breaks in crystalline cellulose can oxidatively disturb the crystalline surface by disrupting hydrogen bonds. HS-AFM observations showed that AA9D increased the number of Cel7D molecules moving on the substrate surface and increased the processivity of Cel7D, thereby increasing the depolymerization performance, suggesting that AA9D not only generates chain ends but also amorphizes the crystalline surface, thereby increasing the activity of CBHs.
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Affiliation(s)
- Taku Uchiyama
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takayuki Uchihashi
- Department of Physics and Structural Biology Research Center, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan
- Department of Physics, Structural Biology Center, and Institute for Glyco-core Research (iGCORE), Nagoya University, Nagoya, 464-8602, Japan
| | - Takuya Ishida
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Akihiko Nakamura
- Department of Applied Life Sciences, Faculty of Agriculture, Shizuoka University, Suruga-ku, Shizuoka 422-8529, Japan
| | - Josh V. Vermaas
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Michael F. Crowley
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Masahiro Samejima
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Faculty of Engineering, Shinshu University, 4-17-1, Wakasato, Nagano 380-8533, Japan
| | - Gregg T. Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Kiyohiko Igarashi
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- VTT Technical Research Center of Finland Ltd., Tietotie 2, P.O. Box 1000, Espoo, FI-02044 VTT, Finland
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21
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Qin X, Zou J, Yang K, Li J, Wang X, Tu T, Wang Y, Yao B, Huang H, Luo H. Deciphering the efficient cellulose degradation by the thermophilic fungus Myceliophthora thermophila focused on the synergistic action of glycoside hydrolases and lytic polysaccharide monooxygenases. BIORESOURCE TECHNOLOGY 2022; 364:128027. [PMID: 36174898 DOI: 10.1016/j.biortech.2022.128027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The thermophilic fungus Myceliophthora thermophila as an efficient decomposer secretes various glycoside hydrolases and auxiliary oxidation enzymes to deconstruct cellulose. However, the core enzymes critical for efficient cellulose degradation and their interactions with other cellulolytic enzymes remain unclear. Herein, the transcriptomic analysis of M. thermophila grown on Avicel exhibited that cellulases from GH5_5, GH6 and GH7, and lytic polysaccharide monooxygenases (LPMOs) from AA9 contributed to cellulose degradation. Moreover, the peptide mass fingerprinting analysis of major extracellular proteins and corresponding gene-knockout strains studies revealed that MtCel7A and MtCel5A were the core cellulolytic enzymes. Furthermore, synergistic experiments found that hydrolytic efficiencies of MtCel7A and MtCel5A were both improved by mixture C1/C4 oxidizing MtLPMO9H, but inhibited by C1 oxidizing MtLPMO9E and C4 oxidizing MtLPMO9J respectively. These results demonstrated the potential application of C1/C4 oxidizing LPMOs for future designing novel cellulolytic enzyme cocktails on the efficient conversion of cellulose into biofuels and biochemicals.
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Affiliation(s)
- Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jiahuan Zou
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kun Yang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jinyang Li
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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22
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Roles of PKAc1 and CRE1 in cellulose degradation, conidiation, and yellow pigment synthesis in Trichoderma reesei QM6a. Biotechnol Lett 2022; 44:1465-1475. [PMID: 36269496 DOI: 10.1007/s10529-022-03312-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/11/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE This study aimed to reveal the roles of the protein kinase A catalytic subunit 1 (pkac1) and carbon catabolite repressor cre1 genes in cellulase production by Trichoderma reesei wild-type strain QM6a. Our strategy might be useful to construct a high-yielding cellulase strain for its wide application. METHODS This paper describes cellulase activity, plate conidiation, and yellow pigment synthesis assays of QM6a with the disruption of pkac1 and cre1. RESULTS Deletion of pkac1 (Δpkac1) had no effect on cellulase production or transcript levels of major cellulase genes in the presence of cellulose. Disruption of cre1 (Δcre1) resulted in a remarkable increase in cellulase production and expression of the four major cellulase genes. Double disruption of pkac1 and cre1 significantly improved enzyme activity and protein production. The double disruption also resulted in a significant reduction in yellow pigment production and abrogated conidial production. CONCLUSION Double deletion of pkac1 and cre1 led to increased hydrolytic enzyme production in T. reesei using cellulose as a carbon source.
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23
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Chang H, Gacias Amengual N, Botz A, Schwaiger L, Kracher D, Scheiblbrandner S, Csarman F, Ludwig R. Investigating lytic polysaccharide monooxygenase-assisted wood cell wall degradation with microsensors. Nat Commun 2022; 13:6258. [PMID: 36271009 PMCID: PMC9586961 DOI: 10.1038/s41467-022-33963-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 10/10/2022] [Indexed: 12/25/2022] Open
Abstract
Lytic polysaccharide monooxygenase (LPMO) supports biomass hydrolysis by increasing saccharification efficiency and rate. Recent studies demonstrate that H2O2 rather than O2 is the cosubstrate of the LPMO-catalyzed depolymerization of polysaccharides. Some studies have questioned the physiological relevance of the H2O2-based mechanism for plant cell wall degradation. This study reports the localized and time-resolved determination of LPMO activity on poplar wood cell walls by measuring the H2O2 concentration in their vicinity with a piezo-controlled H2O2 microsensor. The investigated Neurospora crassa LPMO binds to the inner cell wall layer and consumes enzymatically generated H2O2. The results point towards a high catalytic efficiency of LPMO at a low H2O2 concentration that auxiliary oxidoreductases in fungal secretomes can easily generate. Measurements with a glucose microbiosensor additionally demonstrate that LPMO promotes cellobiohydrolase activity on wood cell walls and plays a synergistic role in the fungal extracellular catabolism and in industrial biomass degradation.
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Affiliation(s)
- Hucheng Chang
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Neus Gacias Amengual
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Alexander Botz
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Lorenz Schwaiger
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Daniel Kracher
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria ,grid.410413.30000 0001 2294 748XPresent Address: Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Stefan Scheiblbrandner
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Florian Csarman
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Roland Ludwig
- grid.5173.00000 0001 2298 5320Department of Food Science and Technology, Institute of Food Technology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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24
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Long L, Hu Y, Sun F, Gao W, Hao Z, Yin H. Advances in lytic polysaccharide monooxygenases with the cellulose-degrading auxiliary activity family 9 to facilitate cellulose degradation for biorefinery. Int J Biol Macromol 2022; 219:68-83. [PMID: 35931294 DOI: 10.1016/j.ijbiomac.2022.07.240] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 11/18/2022]
Abstract
One crucial step in processing the recalcitrant lignocellulosic biomass is the fast hydrolysis of natural cellulose to fermentable sugars that can be subsequently converted to biofuels and bio-based chemicals. Recent studies have shown that lytic polysaccharide monooxygenase (LPMOs) with auxiliary activity family 9 (AA9) are capable of efficiently depolymerizing the crystalline cellulose via regioselective oxidation reaction. Intriguingly, the catalysis by AA9 LPMOs requires reductant to provide electrons, and lignin and its phenolic derivatives can be oxidized, releasing reductant to activate the reaction. The activity of AA9 LPMOs can be enhanced by in-situ generation of H2O2 in the presence of O2. Although scientific understanding of these enzymes remains somewhat unknown or controversial, structure modifications on AA9 LPMOs through protein engineering have emerged in recent years, which are prerequisite for their extensive applications in the development of cellulase-mediated lignocellulosic biorefinery processes. In this review, we critically comment on advances in studies for AA9 LPMOs, i.e., characteristic of AA9 LPMOs catalysis, external electron donors to AA9 LPMOs, especially the role of the oxidization of lignin and its derivatives, and AA9 LPMOs protein engineering as well as their extensive applications in the bioprocessing of lignocellulosic biomass. Perspectives are also highlighted for addressing the challenges.
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Affiliation(s)
- Lingfeng Long
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yun Hu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Wa Gao
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS(, Dalian 116023, China
| | - Zhikui Hao
- Institute of Applied Biotechnology, School of Medicine and Pharmaceutical Engineering, Taizhou Vocational and Technical College, Taizhou 318000, China
| | - Heng Yin
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS(, Dalian 116023, China
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25
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Espinheira RP, Rocha VAL, Guimarães TM, Oliveira CA, de Souza MF, Domont GB, Nogueira FCS, Teixeira RSS, Bon EPDS, Silva ASD. Aspergillus awamori endoglucanase-rich supernatant enhances lignocellulosic biomass liquefaction in high-solids enzymatic hydrolysis. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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26
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Liu N, Yu W, Guo X, Chen J, Xia D, Yu J, Li D. Oxidative cleavage of cellulose in the horse gut. Microb Cell Fact 2022; 21:38. [PMID: 35279161 PMCID: PMC8917663 DOI: 10.1186/s12934-022-01767-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/01/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Lytic polysaccharide monooxygenases (LPMOs) belonging to the auxiliary activity 9 family (AA9) are widely found in aerobic fungi. These enzymes are O2-dependent copper oxidoreductases that catalyze the oxidative cleavage of cellulose. However, studies that have investigated AA9 LPMOs of aerobic fungi in the herbivore gut are scare. To date, whether oxidative cleavage of cellulose occurs in the herbivore gut is unknown.
Results
We report for the first time experimental evidence that AA9 LPMOs from aerobic thermophilic fungi catalyze the oxidative cleavage of cellulose present in the horse gut to C1-oxidized cellulose and C1- and C4-oxidized cello-oligosaccharides. We isolated and identified three thermophilic fungi and measured their growth and AA9 LPMO expression at 37 °C in vitro. We also assessed the expression and the presence of AA9 LPMOs from thermophilic fungi in situ. Finally, we used two recombinant AA9 LPMOs and a native AA9 LPMO from thermophilic fungi to cleave cellulose to yield C1-oxidized products at 37 °C in vitro.
Conclusions
The oxidative cleavage of cellulose occurs in the horse gut. This finding will broaden the known the biological functions of the ubiquitous LPMOs and aid in determining biological significance of aerobic thermophilic fungi.
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27
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Synergy of Cellulase Systems between Acetivibrio thermocellus and Thermoclostridium stercorarium in Consolidated-Bioprocessing for Cellulosic Ethanol. Microorganisms 2022; 10:microorganisms10030502. [PMID: 35336078 PMCID: PMC8951355 DOI: 10.3390/microorganisms10030502] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 11/18/2022] Open
Abstract
Anaerobes harbor some of the most efficient biological machinery for cellulose degradation, especially thermophilic bacteria, such as Acetivibrio thermocellus and Thermoclostridium stercorarium, which play a fundamental role in transferring lignocellulose into ethanol through consolidated bioprocessing (CBP). In this study, we compared activities of two cellulase systems under varying kinds of hemicellulose and cellulose. A. thermocellus was identified to contribute specifically to cellulose hydrolysis, whereas T. stercorarium contributes to hemicellulose hydrolysis. The two systems were assayed in various combinations to assess their synergistic effects using cellulose and corn stover as the substrates. Their maximum synergy degrees on cellulose and corn stover were, respectively, 1.26 and 1.87 at the ratio of 3:2. Furthermore, co-culture of these anaerobes on the mixture of cellulose and xylan increased ethanol concentration from 21.0 to 40.4 mM with a high cellulose/xylan-to-ethanol conversion rate of up to 20.7%, while the conversion rates of T. stercorarium and A. thermocellus monocultures were 19.3% and 15.2%. The reason is that A. thermocellus had the ability to rapidly degrade cellulose while T. stercorarium co-utilized both pentose and hexose, the metabolites of cellulose degradation, to produce ethanol. The synergistic effect of cellulase systems and metabolic pathways in A. thermocellus and T. stercorarium provides a novel strategy for the design, selection, and optimization of ethanol production from cellulosic biomass through CBP.
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28
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Karnaouri A, Chorozian K, Zouraris D, Karantonis A, Topakas E, Rova U, Christakopoulos P. Lytic polysaccharide monooxygenases as powerful tools in enzymatically assisted preparation of nano-scaled cellulose from lignocellulose: A review. BIORESOURCE TECHNOLOGY 2022; 345:126491. [PMID: 34871721 DOI: 10.1016/j.biortech.2021.126491] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 06/13/2023]
Abstract
Nanocellulose, either in the form of fibers or crystals, constitutes a renewable, biobased, biocompatible material with advantageous mechanical properties that can be isolated from lignocellulosic biomass. Enzyme-assisted isolation of nanocellulose is an attractive, environmentally friendly approach that leads to products of higher quality compared to their chemically prepared counterparts. Lytic polysaccharide monooxygenases (LPMOs) are enzymes that oxidatively cleave the β-1,4-glycosidic bond of polysaccharides upon activation of O2 or H2O2 and presence of an electron donor. Their use for treatment of cellulose fibers towards the preparation of nano-scaled cellulose is related to the ability of LPMOs to create nicking points on the fiber surface, thus facilitating fiber disruption and separation. The aim of this review is to describe the mode of action of LPMOs on cellulose fibers towards the isolation of nanostructures, thus highlighting their great potential for the production of nanocellulose as a novel value added product from lignocellulose.
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Affiliation(s)
- Anthi Karnaouri
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Lab, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece; Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
| | - Koar Chorozian
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Lab, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Dimitrios Zouraris
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece
| | - Antonis Karantonis
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou, 15780 Athens, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Lab, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Ulrika Rova
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
| | - Paul Christakopoulos
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
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29
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Comparison of six lytic polysaccharide monooxygenases from Thermothielavioides terrestris shows that functional variation underlies the multiplicity of LPMO genes in filamentous fungi. Appl Environ Microbiol 2022; 88:e0009622. [PMID: 35080911 PMCID: PMC8939357 DOI: 10.1128/aem.00096-22] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are mono-copper enzymes that oxidatively degrade various polysaccharides. Genes encoding LPMOs in the AA9 family are abundant in filamentous fungi while their multiplicity remains elusive. We describe a detailed functional characterization of six AA9 LPMOs from the ascomycetous fungus Thermothielavioides terrestris LPH172 (syn. Thielavia terrestris). These six LPMOs were shown to be upregulated during growth on different lignocellulosic substrates in our previous study. Here, we produced them heterologously in Pichia pastoris and tested their activity on various model and native plant cell wall substrates. All six T. terrestris AA9 (TtAA9) LPMOs produced hydrogen peroxide in the absence of polysaccharide substrate and displayed peroxidase-like activity on a model substrate, yet only five of them were active on selected cellulosic substrates. TtLPMO9A and TtLPMO9E were also active on birch acetylated glucuronoxylan, but only when the xylan was combined with phosphoric acid-swollen cellulose (PASC). Another of the six AA9s, TtLPMO9G, was active on spruce arabinoglucuronoxylan mixed with PASC. TtLPMO9A, TtLPMO9E, TtLPMO9G, and TtLPMO9T could degrade tamarind xyloglucan and, with the exception of TtLPMO9T, beechwood xylan when combined with PASC. Interestingly, none of the tested enzymes were active on wheat arabinoxylan, konjac glucomannan, acetylated spruce galactoglucomannan, or cellopentaose. Overall, these functional analyses support the hypothesis that the multiplicity of the fungal LPMO genes assessed in this study relates to the complex and recalcitrant structure of lignocellulosic biomass. Our study also highlights the importance of using native substrates in functional characterization of LPMOs, as we were able to demonstrate distinct, previously unreported xylan-degrading activities of AA9 LPMOs using such substrates. IMPORTANCE The discovery of LPMOs in 2010 has revolutionized the industrial biotechnology field, mainly by increasing the efficiency of cellulolytic enzyme cocktails. Nonetheless, the biological purpose of the multiplicity of LPMO-encoding genes in filamentous fungi has remained an open question. Here, we address this point by showing that six AA9 LPMOs from a single fungal strain have various substrate preferences and activities on tested cellulosic and hemicellulosic substrates, including several native xylan substrates. Importantly, several of these activities could only be detected when using copolymeric substrates that likely resemble plant cell walls more than single fractionated polysaccharides do. Our results suggest that LPMOs have evolved to contribute to the degradation of different complex structures in plant cell walls where different biomass polymers are closely associated. This knowledge together with the elucidated novel xylanolytic activities could aid in further optimization of enzymatic cocktails for efficient degradation of lignocellulosic substrates and more.
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30
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Schmitz E, Leontakianakou S, Norlander S, Nordberg Karlsson E, Adlercreutz P. Lignocellulose degradation for the bioeconomy: The potential of enzyme synergies between xylanases, ferulic acid esterase and laccase for the production of arabinoxylo-oligosaccharides. BIORESOURCE TECHNOLOGY 2022; 343:126114. [PMID: 34648963 DOI: 10.1016/j.biortech.2021.126114] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
The success of establishing bioeconomies replacing current economies based on fossil resources largely depends on our ability to degrade recalcitrant lignocellulosic biomass. This study explores the potential of employing various enzymes acting synergistically on previously pretreated agricultural side streams (corn bran, oat hull, soluble and insoluble oat bran). Degrees of synergy (oligosaccharide yield obtained with the enzyme combination divided by the sum of yields obtained with individual enzymes) of up to 88 were obtained. Combinations of a ferulic acid esterase and xylanases resulted in synergy on all substrates, while a laccase and xylanases only acted synergistically on the more recalcitrant substrates. Synergy between different xylanases (glycoside hydrolase (GH) families 5 and 11) was observed particularly on oat hulls, producing a yield of 57%. The synergistic ability of the enzymes was found to be partly due to the increased enzyme stability when in combination with the substrates.
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Affiliation(s)
- Eva Schmitz
- Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund, SE-22100, Sweden.
| | - Savvina Leontakianakou
- Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund, SE-22100, Sweden
| | - Siri Norlander
- Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund, SE-22100, Sweden
| | - Eva Nordberg Karlsson
- Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund, SE-22100, Sweden
| | - Patrick Adlercreutz
- Biotechnology, Department of Chemistry, Lund University, PO Box 124, Lund, SE-22100, Sweden
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31
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Inhibition of LPMOs by Fermented Persimmon Juice. Biomolecules 2021; 11:biom11121890. [PMID: 34944533 PMCID: PMC8699118 DOI: 10.3390/biom11121890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 02/03/2023] Open
Abstract
Fermented persimmon juice, Kakishibu, has traditionally been used for wood and paper protection. This protective effect stems at least partially from inhibition of microbial cellulose degrading enzymes. The inhibitory effect of Kakishibu on lytic polysaccharide monooxygenases (LPMOs) and on a cocktail of cellulose hydrolases was studied, using three different cellulosic substrates. Dose dependent inhibition of LPMO activity by a commercial Kakishibu product was assessed for the well-characterized LPMO from Thermoascus aurantiacus TaAA9A, and the inhibitory effect was confirmed on five additional microbial LPMOs. The model tannin compound, tannic acid exhibited a similar inhibitory effect on TaAA9A as Kakishibu. It was further shown that both polyethylene glycol and tannase can alleviate the inhibitory effect of Kakishibu and tannic acid, indicating a likely mechanism of inhibition caused by unspecific tannin-protein interactions.
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32
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Zerva A, Pentari C, Ferousi C, Nikolaivits E, Karnaouri A, Topakas E. Recent advances on key enzymatic activities for the utilisation of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2021; 342:126058. [PMID: 34597805 DOI: 10.1016/j.biortech.2021.126058] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
The field of enzymatic degradation of lignocellulose is actively growing and the recent updates of the last few years indicate that there is still much to learn. The growing number of protein sequences with unknown function in microbial genomes indicates that there is still much to learn on the mechanisms of lignocellulose degradation. In this review, a summary of the progress in the field is presented, including recent discoveries on the nature of the structural polysaccharides, new technologies for the discovery and functional annotation of gene sequences including omics technologies, and the novel lignocellulose-acting enzymes described. Novel enzymatic activities and enzyme families as well as accessory enzymes and their synergistic relationships regarding biomass breakdown are described. Moreover, it is shown that all the valuable knowledge of the enzymatic decomposition of plant biomass polymers can be employed towards the decomposition and upgrading of synthetic polymers, such as plastics.
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Affiliation(s)
- Anastasia Zerva
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Christina Pentari
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Christina Ferousi
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Efstratios Nikolaivits
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Anthi Karnaouri
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece; Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
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33
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Støpamo FG, Røhr ÅK, Mekasha S, Petrović DM, Várnai A, Eijsink VGH. Characterization of a lytic polysaccharide monooxygenase from Aspergillus fumigatus shows functional variation among family AA11 fungal LPMOs. J Biol Chem 2021; 297:101421. [PMID: 34798071 PMCID: PMC8668981 DOI: 10.1016/j.jbc.2021.101421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 11/26/2022] Open
Abstract
The discovery of oxidative cleavage of recalcitrant polysaccharides by lytic polysaccharide monooxygenases (LPMOs) has affected the study and industrial application of enzymatic biomass processing. Despite being widespread in fungi, LPMOs belonging to the auxiliary activity (AA) family AA11 have been understudied. While these LPMOs are considered chitin active, some family members have little or no activity toward chitin, and the only available crystal structure of an AA11 LPMO lacks features found in bacterial chitin-active AA10 LPMOs. Here, we report structural and functional characteristics of a single-domain AA11 LPMO from Aspergillus fumigatus, AfAA11A. The crystal structure shows a substrate-binding surface with features resembling those of known chitin-active LPMOs. Indeed, despite the absence of a carbohydrate-binding module, AfAA11A has considerable affinity for α-chitin and, more so, β-chitin. AfAA11A is active toward both these chitin allomorphs and enhances chitin degradation by an endoacting chitinase, in particular for α-chitin. The catalytic activity of AfAA11A on chitin increases when supplying reactions with hydrogen peroxide, showing that, like LPMOs from other families, AfAA11A has peroxygenase activity. These results show that, in stark contrast to the previously characterized AfAA11B from the same organism, AfAA11A likely plays a role in fungal chitin turnover. Thus, members of the hitherto rather enigmatic family of AA11 LPMOs show considerable structural and functional differences and may have multiple roles in fungal physiology.
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Affiliation(s)
- Fredrik Gjerstad Støpamo
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Åsmund Kjendseth Røhr
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Sophanit Mekasha
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Dejan M Petrović
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
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34
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Zhang X, Chen K, Long L, Ding S. Two C1-oxidizing AA9 lytic polysaccharide monooxygenases from Sordaria brevicollis differ in thermostability, activity, and synergy with cellulase. Appl Microbiol Biotechnol 2021; 105:8739-8759. [PMID: 34748039 DOI: 10.1007/s00253-021-11677-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 11/24/2022]
Abstract
Cellulolytic fungi usually have multiple genes for C1-oxidizing auxiliary activity 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) in their genomes, but their potential functional differences are less understood. In this study, two C1-oxidizing AA9 LPMOs, SbLPMO9A and SbLPMO9B, were identified from Sordaria brevicollis, and their differences, particularly in terms of thermostability, reducing agent specificity, and synergy with cellulase, were explored. The two enzymes exhibited weak binding to cellulose and intolerance to hydrogen peroxide. Their oxidative activity was influenced by cellulose crystallinity and surface morphology, and both enzymes tended to oxidize celluloses of lower crystallinity and high surface area. Comparably, SbLPMO9A had much better thermostability than SbLPMO9B, which may be attributed to the presence of a carbohydrate binding module 1 (CBM1)-like sequence at its C-terminus. In addition, the two enzymes exhibited different specificities and responsivities toward electron donors. SbLPMO9A and SbLPMO9B were able to boost the catalytic efficiency of endoglucanase I (EGI) on physically and chemically pretreated substrates but with different degrees of synergy. Substrate- and enzyme-specific synergism was observed by comparing the synergistic action of SbLPMO9A or SbLPMO9B with commercial Celluclast 1.5L on three kinds of cellulosic substrates. On regenerated amorphous cellulose and PFI (Papirindustriens Forskningsinstitut)-fibrillated bleached eucalyptus pulp, SbLPMO9B showed a higher synergistic effect than SbLPMO9A, while on delignified wheat straw, the synergistic effect of SbLPMO9A was higher than that of SbLPMO9B. On account of its excellent thermostability and boosting effect on the enzymatic hydrolysis of delignified wheat straw, SbLPMO9A may have high application potential in biorefineries for lignocellulosic biomass. KEY POINTS: • C1-oxidizing SbLPMO9A displayed higher thermostability than SbLPMO9B, probably due to the presence of a CBM1-like module. • The oxidative activity of the two SbLPMO9s on celluloses increased with decreasing cellulose crystallinity or increasing beating degree. • The two SbLPMO9s boosted the catalytic efficiency of cellulase, but the synergistic effect was substrate- and enzyme-specific.
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Affiliation(s)
- Xi Zhang
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Kaixiang Chen
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Liangkun Long
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Shaojun Ding
- The Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
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Defining the Frontiers of Synergism between Cellulolytic Enzymes for Improved Hydrolysis of Lignocellulosic Feedstocks. Catalysts 2021. [DOI: 10.3390/catal11111343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lignocellulose has economic potential as a bio-resource for the production of value-added products (VAPs) and biofuels. The commercialization of biofuels and VAPs requires efficient enzyme cocktail activities that can lower their costs. However, the basis of the synergism between enzymes that compose cellulolytic enzyme cocktails for depolymerizing lignocellulose is not understood. This review aims to address the degree of synergism (DS) thresholds between the cellulolytic enzymes and how this can be used in the formulation of effective cellulolytic enzyme cocktails. DS is a powerful tool that distinguishes between enzymes’ synergism and anti-synergism during the hydrolysis of biomass. It has been established that cellulases, or cellulases and lytic polysaccharide monooxygenases (LPMOs), always synergize during cellulose hydrolysis. However, recent evidence suggests that this is not always the case, as synergism depends on the specific mechanism of action of each enzyme in the combination. Additionally, expansins, nonenzymatic proteins responsible for loosening cell wall fibers, seem to also synergize with cellulases during biomass depolymerization. This review highlighted the following four key factors linked to DS: (1) a DS threshold at which the enzymes synergize and produce a higher product yield than their theoretical sum, (2) a DS threshold at which the enzymes display synergism, but not a higher product yield, (3) a DS threshold at which enzymes do not synergize, and (4) a DS threshold that displays anti-synergy. This review deconvolutes the DS concept for cellulolytic enzymes, to postulate an experimental design approach for achieving higher synergism and cellulose conversion yields.
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Tokin R, Frandsen KEH, Ipsen JØ, Lo Leggio L, Poojary MM, Berrin JG, Grisel S, Brander S, Jensen PE, Johansen KS. Inhibition of lytic polysaccharide monooxygenase by natural plant extracts. THE NEW PHYTOLOGIST 2021; 232:1337-1349. [PMID: 34389999 DOI: 10.1111/nph.17676] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/25/2021] [Indexed: 06/13/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are monocopper enzymes of industrial and biological importance. In particular, LPMOs play important roles in fungal lifestyle. No inhibitors of LPMOs have yet been reported. In this study, a diverse library of 100 plant extracts was screened for LPMO activity-modulating effects. By employing protein crystallography and LC-MS, we successfully identified a natural LPMO inhibitor. Extract screening revealed a significant LPMO inhibition by methanolic extract of Cinnamomum cassia (cinnamon), which inhibited LsAA9A LPMO from Lentinus similis in a concentration-dependent manner. With a notable exception, other microbial LPMOs from families AA9 and AA10 were also inhibited by this cinnamon extract. The polyphenol cinnamtannin B1 was identified as the inhibitory component by crystallography. Cinnamtannin B1 was bound to the surface of LsAA9A at two distinct binding sites: one close to the active site and another at a pocket on the opposite side of the protein. Independent characterization of cinnamon extract by LC-MS and subsequent activity measurements confirmed that the compound inhibiting LsAA9A was cinnamtannin B1. The results of this study show that specific natural LPMO inhibitors of plant origin exist in nature, providing the opportunity for future exploitation of such compounds within various biotechnological contexts.
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Affiliation(s)
- Radina Tokin
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, 1871, Denmark
| | - Kristian E H Frandsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, 1871, Denmark
- Department of Chemistry, University of Copenhagen, Copenhagen Ø, 2100, Denmark
| | - Johan Ørskov Ipsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, 1871, Denmark
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, Copenhagen Ø, 2100, Denmark
| | - Mahesha M Poojary
- Department of Food Science, University of Copenhagen, Frederiksberg C, 1958, Denmark
| | - Jean-Guy Berrin
- INRAE, Aix Marseille Université, Biodiversité et Biotechnologie Fongiques (BBF), Marseille, 13009, France
| | - Sacha Grisel
- INRAE, Aix Marseille Université, Biodiversité et Biotechnologie Fongiques (BBF), Marseille, 13009, France
| | - Søren Brander
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, 1958, Denmark
| | - Poul Erik Jensen
- Department of Food Science, University of Copenhagen, Frederiksberg C, 1958, Denmark
| | - Katja Salomon Johansen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, 1958, Denmark
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Long L, Sun L, Ding D, Chen K, Lin Q, Ding S. Two C1-oxidizing lytic polysaccharide monooxygenases from Ceriporiopsis subvermispora enhance the saccharification of wheat straw by a commercial cellulase cocktail. Process Biochem 2021. [DOI: 10.1016/j.procbio.2021.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Głazowska S, Mravec J. An aptamer highly specific to cellulose enables the analysis of the association of cellulose with matrix cell wall polymers in vitro and in muro. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:579-599. [PMID: 34314513 DOI: 10.1111/tpj.15442] [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: 04/21/2021] [Revised: 06/27/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
The current toolbox of cell wall-directed molecular probes has been pivotal for advancing basic and application-oriented plant carbohydrate research; however, it still exhibits limitations regarding target diversity and specificity. Scarcity of probes targeting intramolecular associations between cell wall polymers particularly hinders our understanding of the cell wall microstructure and affects the development of effective means for its efficient deconstruction for bioconversion. Here we report a detailed characterization of a cellulose-binding DNA aptamer CELAPT MINI using a combination of various in vitro biochemical, biophysical, and molecular biology techniques. Our results show evidence for its high specificity towards long non-substituted β-(1-4)-glucan chains in both crystalline and amorphous forms. Fluorescent conjugates of CELAPT MINI are applicable as in situ cellulose probes and are well suited for various microscopy techniques, including super-resolution imaging. Compatibility of fluorescent CELAPT MINI variants with immunodetection of cell wall matrix polymers enabled them simultaneously to resolve the fibrillar organization of complex cellulose-enriched pulp material and to quantify the level of cellulose masking by xyloglucan and xylan. Using enzymatically, chemically, or genetically modulated Brachypodium internode sections we showed the diversity in cell wall packing among various cell types and even cell wall microdomains. We showed that xylan is the most prominent, but not the only, cellulose-masking agent in Brachypodium internode tissues. These results collectively highlight the hitherto unexplored potential to expand the cell wall probing toolbox with highly specific and versatile in vitro generated polynucleotide probes.
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Affiliation(s)
- Sylwia Głazowska
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
| | - Jozef Mravec
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
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Semenova MV, Gusakov AV, Telitsin VD, Sinitsyn AP. Enzymatic Destruction of Cellulose: Characteristics of the Kinetic Interaction of Lytic Polysaccharide Monooxygenases and Individual Cellulases. APPL BIOCHEM MICRO+ 2021. [DOI: 10.1134/s0003683821050136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Bhatia S, Yadav SK. Novel catalytic potential of a hyperthermostable mono‑copper oxidase (LPMO-AOAA17) for the oxidation of lignin monomers and depolymerisation of lignin dimer in aqueous media. Int J Biol Macromol 2021; 186:563-573. [PMID: 34273339 DOI: 10.1016/j.ijbiomac.2021.07.063] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/06/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
Abstract
Lytic polysaccharide monooxygenase (LPMO) are mono‑copper enzymes known for the oxidative cleavage of recalcitrant polysaccharides with their intriguing and unique catalytic chemistry. Such impeccable oxidation potential has made them highly valuable in the enzymatic consortia for the degradation of ligno-cellulosic biomass. Bioinformatic analysis has revealed an unannotated LPMO gene in the genome of A. oryzae. Multiple sequence alignment showed the presence of conserved "histidine brace" of LPMO in the amino acid sequence of the enzyme. The enzyme, named as LPMO-AOAA17 was recombinantly expressed in E. coli BL21 and characterised for its substrate specificity. Recombinant enzyme did not show any characteristic cleavage of polysaccharides. However, it was found to be oxidising broad range of phenolic and non-phenolic monomers of lignin. Biochemical study revealed the optimum activity of LPMO-AOAA17 at pH 7 and was highly stable and active at 100 °C. The enzyme LPMO-AOAA17 was also observed to be stable after autoclaving at 121 °C and 15 psi. Thermal stability of the LPMO-AOAA17 was further confirmed through differential scanning calorimetry. GC-MS analysis has confirmed the catalysis of LPMO-AOAA17 for the depolymerisation of lignin dimer, guaicyl glycerol β-guaicyl ether into guaiacol. This study has first time documented the identification of a hyperthermostable LPMO for oxidative cleavage of β-O-4 linkage of lignin compounds to form aromatic products in aqueous media.
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Affiliation(s)
- Simran Bhatia
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali 140306, Punjab, India
| | - Sudesh Kumar Yadav
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali 140306, Punjab, India.
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Chen K, Zhang X, Long L, Ding S. Comparison of C4-oxidizing and C1/C4-oxidizing AA9 LPMOs in substrate adsorption, H 2O 2-driven activity and synergy with cellulase on celluloses of different crystallinity. Carbohydr Polym 2021; 269:118305. [PMID: 34294322 DOI: 10.1016/j.carbpol.2021.118305] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 11/15/2022]
Abstract
Two C1/C4-oxidizing AA9 lytic polysaccharide monooxygenases (AA9 LPMOs), AoLPMO9A and AoLPMO9B, and one C4-oxidizing AoLPMO9C from Aspergillus oryzae, were characterized and compared with the well-studied C4-oxidizing NcLPMO9C. NcLPMO9C and AoLPMO9C harboring carbohydrate-binding module 1 (CBM1) exhibited much stronger adsorption capacity than AoLPMO9A and B without CBM1. The binding affinity is crucial for the efficacy of H2O2 as cosubstrate and oxidative activity of AA9 LPMOs on crystalline cellulose. C4-oxidizing AA9 LPMOs had a striking boosting effect on cellobiohydrolase I (CBHI), while C1/C4-oxidizing AA9 LPMOs boosted CBHII and endoglucanase I (EGI) activity. Our results indicated that two types of AA9 LPMOs with different modularities and regioselectivities varied in cellulose adsorption, H2O2-driven activity and synergy with cellulase on celluloses of different crystallinity which could complement each other in lignocellulose degradation. C4-oxidizing AA9 LPMOs with CBM1 were particularly essential in cellulase cocktail due to high H2O2-driven activity and a striking boosting effect on CBHI.
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Affiliation(s)
- Kaixiang Chen
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Xi Zhang
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Liangkun Long
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
| | - Shaojun Ding
- The Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
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A comparative biochemical investigation of the impeding effect of C1-oxidizing LPMOs on cellobiohydrolases. J Biol Chem 2021; 296:100504. [PMID: 33675751 PMCID: PMC8047454 DOI: 10.1016/j.jbc.2021.100504] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/17/2021] [Accepted: 03/02/2021] [Indexed: 11/20/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are known to act synergistically with glycoside hydrolases in industrial cellulolytic cocktails. However, a few studies have reported severe impeding effects of C1-oxidizing LPMOs on the activity of reducing-end cellobiohydrolases. The mechanism for this effect remains unknown, but it may have important implications as reducing-end cellobiohydrolases make up a significant part of such cocktails. To elucidate whether the impeding effect is general for different reducing-end cellobiohydrolases and study the underlying mechanism, we conducted a comparative biochemical investigation of the cooperation between a C1-oxidizing LPMO from Thielavia terrestris and three reducing-end cellobiohydrolases; Trichoderma reesei (TrCel7A), T. terrestris (TtCel7A), and Myceliophthora heterothallica (MhCel7A). The enzymes were heterologously expressed in the same organism and thoroughly characterized biochemically. The data showed distinct differences in synergistic effects between the LPMO and the cellobiohydrolases; TrCel7A was severely impeded, TtCel7A was moderately impeded, while MhCel7A was slightly boosted by the LPMO. We investigated effects of C1-oxidations on cellulose chains on the activity of the cellobiohydrolases and found reduced activity against oxidized cellulose in steady-state and pre-steady-state experiments. The oxidations led to reduced maximal velocity of the cellobiohydrolases and reduced rates of substrate complexation. The extent of these effects differed for the cellobiohydrolases and scaled with the extent of the impeding effect observed in the synergy experiments. Based on these results, we suggest that C1-oxidized chain ends are poor attack sites for reducing-end cellobiohydrolases. The severity of the impeding effects varied considerably among the cellobiohydrolases, which may be relevant to consider for optimization of industrial cocktails.
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Kadić A, Várnai A, Eijsink VGH, Horn SJ, Lidén G. In situ measurements of oxidation-reduction potential and hydrogen peroxide concentration as tools for revealing LPMO inactivation during enzymatic saccharification of cellulose. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:46. [PMID: 33602308 PMCID: PMC7893893 DOI: 10.1186/s13068-021-01894-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Biochemical conversion of lignocellulosic biomass to simple sugars at commercial scale is hampered by the high cost of saccharifying enzymes. Lytic polysaccharide monooxygenases (LPMOs) may hold the key to overcome economic barriers. Recent studies have shown that controlled activation of LPMOs by a continuous H2O2 supply can boost saccharification yields, while overdosing H2O2 may lead to enzyme inactivation and reduce overall sugar yields. While following LPMO action by ex situ analysis of LPMO products confirms enzyme inactivation, currently no preventive measures are available to intervene before complete inactivation. RESULTS Here, we carried out enzymatic saccharification of the model cellulose Avicel with an LPMO-containing enzyme preparation (Cellic CTec3) and H2O2 feed at 1 L bioreactor scale and followed the oxidation-reduction potential and H2O2 concentration in situ with corresponding electrode probes. The rate of oxidation of the reductant as well as the estimation of the amount of H2O2 consumed by LPMOs indicate that, in addition to oxidative depolymerization of cellulose, LPMOs consume H2O2 in a futile non-catalytic cycle, and that inactivation of LPMOs happens gradually and starts long before the accumulation of LPMO-generated oxidative products comes to a halt. CONCLUSION Our results indicate that, in this model system, the collapse of the LPMO-catalyzed reaction may be predicted by the rate of oxidation of the reductant, the accumulation of H2O2 in the reactor or, indirectly, by a clear increase in the oxidation-reduction potential. Being able to monitor the state of the LPMO activity in situ may help maximizing the benefit of LPMO action during saccharification. Overcoming enzyme inactivation could allow improving overall saccharification yields beyond the state of the art while lowering LPMO and, potentially, cellulase loads, both of which would have beneficial consequences on process economics.
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Affiliation(s)
- Adnan Kadić
- Department of Chemical Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, NO-1432, Ås, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, NO-1432, Ås, Norway
| | - Svein Jarle Horn
- Faculty of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, NO-1432, Ås, Norway.
| | - Gunnar Lidén
- Department of Chemical Engineering, Lund University, P.O. Box 118, 221 00, Lund, Sweden.
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Lytic polysaccharide monooxygenases and other histidine-brace copper proteins: structure, oxygen activation and biotechnological applications. Biochem Soc Trans 2021; 49:531-540. [PMID: 33449071 PMCID: PMC7924993 DOI: 10.1042/bst20201031] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 11/17/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are mononuclear copper enzymes that catalyse the oxidative cleavage of glycosidic bonds. They are characterised by two histidine residues that coordinate copper in a configuration termed the Cu-histidine brace. Although first identified in bacteria and fungi, LPMOs have since been found in all biological kingdoms. LPMOs are now included in commercial enzyme cocktails used in industrial biorefineries. This has led to increased process yield due to the synergistic action of LPMOs with glycoside hydrolases. However, the introduction of LPMOs makes control of the enzymatic step in industrial stirred-tank reactors more challenging, and the operational stability of the enzymes is reduced. It is clear that much is still to be learned about the interaction between LPMOs and their complex natural and industrial environments, and fundamental scientific studies are required towards this end. Several atomic-resolution structures have been solved providing detailed information on the Cu-coordination sphere and the interaction with the polysaccharide substrate. However, the molecular mechanisms of LPMOs are still the subject of intense investigation; the key question being how the proteinaceous environment controls the copper cofactor towards the activation of the O-O bond in O2 and cleavage of the glycosidic bonds in polysaccharides. The need for biochemical characterisation of each putative LPMO is discussed based on recent reports showing that not all proteins with a Cu-histidine brace are enzymes.
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Bernardi AV, Gerolamo LE, de Gouvêa PF, Yonamine DK, Pereira LMS, de Oliveira AHC, Uyemura SA, Dinamarco TM. LPMO AfAA9_B and Cellobiohydrolase AfCel6A from A. fumigatus Boost Enzymatic Saccharification Activity of Cellulase Cocktail. Int J Mol Sci 2020; 22:E276. [PMID: 33383972 PMCID: PMC7795096 DOI: 10.3390/ijms22010276] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/21/2020] [Accepted: 12/24/2020] [Indexed: 01/02/2023] Open
Abstract
Cellulose is the most abundant polysaccharide in lignocellulosic biomass, where it is interlinked with lignin and hemicellulose. Bioethanol can be produced from biomass. Since breaking down biomass is difficult, cellulose-active enzymes secreted by filamentous fungi play an important role in degrading recalcitrant lignocellulosic biomass. We characterized a cellobiohydrolase (AfCel6A) and lytic polysaccharide monooxygenase LPMO (AfAA9_B) from Aspergillus fumigatus after they were expressed in Pichia pastoris and purified. The biochemical parameters suggested that the enzymes were stable; the optimal temperature was ~60 °C. Further characterization revealed high turnover numbers (kcat of 147.9 s-1 and 0.64 s-1, respectively). Surprisingly, when combined, AfCel6A and AfAA9_B did not act synergistically. AfCel6A and AfAA9_B association inhibited AfCel6A activity, an outcome that needs to be further investigated. However, AfCel6A or AfAA9_B addition boosted the enzymatic saccharification activity of a cellulase cocktail and the activity of cellulase Af-EGL7. Enzymatic cocktail supplementation with AfCel6A or AfAA9_B boosted the yield of fermentable sugars from complex substrates, especially sugarcane exploded bagasse, by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass.
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Affiliation(s)
- Aline Vianna Bernardi
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
| | - Luis Eduardo Gerolamo
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
| | - Paula Fagundes de Gouvêa
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
| | - Deborah Kimie Yonamine
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
| | - Lucas Matheus Soares Pereira
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
| | - Arthur Henrique Cavalcante de Oliveira
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
| | - Sérgio Akira Uyemura
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-903, Brazil;
| | - Taisa Magnani Dinamarco
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, Brazil; (A.V.B.); (L.E.G.); (P.F.d.G.); (D.K.Y.); (L.M.S.P.); (A.H.C.d.O.)
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46
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Tuveng TR, Jensen MS, Fredriksen L, Vaaje-Kolstad G, Eijsink VGH, Forsberg Z. A thermostable bacterial lytic polysaccharide monooxygenase with high operational stability in a wide temperature range. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:194. [PMID: 33292445 PMCID: PMC7708162 DOI: 10.1186/s13068-020-01834-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Lytic polysaccharide monooxygenases (LPMOs) are oxidative, copper-dependent enzymes that function as powerful tools in the turnover of various biomasses, including lignocellulosic plant biomass. While LPMOs are considered to be of great importance for biorefineries, little is known about industrial relevant properties such as the ability to operate at high temperatures. Here, we describe a thermostable, cellulose-active LPMO from a high-temperature compost metagenome (called mgLPMO10). RESULTS MgLPMO10 was found to have the highest apparent melting temperature (83 °C) reported for an LPMO to date, and is catalytically active up to temperatures of at least 80 °C. Generally, mgLPMO10 showed good activity and operational stability over a wide temperature range. The LPMO boosted cellulose saccharification by recombinantly produced GH48 and GH6 cellobiohydrolases derived from the same metagenome, albeit to a minor extent. Cellulose saccharification studies with a commercial cellulase cocktail (Celluclast®) showed that the performance of this thermostable bacterial LPMO is comparable with that of a frequently utilized fungal LPMO from Thermoascus aurantiacus (TaLPMO9A). CONCLUSIONS The high activity and operational stability of mgLPMO10 are of both fundamental and applied interest. The ability of mgLPMO10 to perform oxidative cleavage of cellulose at 80 °C and the clear synergy with Celluclast® make this enzyme an interesting candidate in the development of thermostable enzyme cocktails for use in lignocellulosic biorefineries.
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Affiliation(s)
- Tina Rise Tuveng
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Marianne Slang Jensen
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Lasse Fredriksen
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway.
| | - Zarah Forsberg
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Aas, Norway.
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47
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Nakagawa YS, Kudo M, Onodera R, Ang LZP, Watanabe T, Totani K, Eijsink VGH, Vaaje-Kolstad G. Analysis of Four Chitin-Active Lytic Polysaccharide Monooxygenases from Streptomyces griseus Reveals Functional Variation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:13641-13650. [PMID: 33151668 DOI: 10.1021/acs.jafc.0c05319] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are redox-active enzymes that cleave insoluble polysaccharides by an oxidative reaction. In the present study, we have characterized four recombinant putative chitin-active LPMOs from Streptomyces griseus (SgLPMO10B, -C, -D, and -F) and evaluated their potential in enhancing hydrolysis of α- and β-chitin by three families of 18 chitinases of Serratia marcescens, SmChiA, -B, and -C. All four recombinant SgLPMO10s showed oxidative activity toward both α- and β-chitin but exhibited different abilities to promote the release of chitobiose from chitin by chitinases depending on both the chitinase and the chitin type. These effects were observed under conditions where the amount of LPMO in the reaction was not rate-limiting, showing that the observed functional differences relate to different abilities of the LPMOs to interact with and act on the substrate. These results show that four seemingly similar LPMOs carrying out the same reaction, cleavage of chitin by C1 oxidation, may have different roles in natural chitin conversion, which provides a rationale for the multiplicity of these enzymes within the same organism. The ability of the LPMOs to act on more natural substrates was demonstrated by showing that SgLPMO10B improved chitin solubilization in dried powdered shrimp shells.
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Affiliation(s)
- Yuko S Nakagawa
- Division of Chemical Engineering and Biotechnology, National Institute of Technology, Ichinoseki College, Ichinoseki Iwate 021-8511, Japan
| | - Madoka Kudo
- Division of Chemical Engineering and Biotechnology, National Institute of Technology, Ichinoseki College, Ichinoseki Iwate 021-8511, Japan
| | - Reiya Onodera
- Division of Chemical Engineering and Biotechnology, National Institute of Technology, Ichinoseki College, Ichinoseki Iwate 021-8511, Japan
| | - Lily Zuin Ping Ang
- Division of Chemical Engineering and Biotechnology, National Institute of Technology, Ichinoseki College, Ichinoseki Iwate 021-8511, Japan
| | - Takeshi Watanabe
- Faculty of Agro-Food Science, Niigata Agro-Food University, Tainai, Niigata 959-2702, Japan
| | - Kazuhide Totani
- Division of Chemical Engineering and Biotechnology, National Institute of Technology, Ichinoseki College, Ichinoseki Iwate 021-8511, Japan
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås 1432, Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, Ås 1432, Norway
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48
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Bunterngsook B, Mhuantong W, Kanokratana P, Iseki Y, Watanabe T, Champreda V. Identification and characterization of a novel AA9-type lytic polysaccharide monooxygenase from a bagasse metagenome. Appl Microbiol Biotechnol 2020; 105:197-210. [PMID: 33230603 DOI: 10.1007/s00253-020-11002-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/20/2020] [Accepted: 11/03/2020] [Indexed: 11/25/2022]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are auxiliary enzymes catalyzing oxidative cleavages of cellulose chains in crystalline regions, resulting in their increasing accessibility to the hydrolytic enzyme counterparts and hence higher released sugars from biomass saccharification. In this study, a novel auxiliary protein family 9 LPMO (BgAA9) was identified from a metagenomic library derived from a thermophilic microbial community in bagasse collection site where diverse AA9 and AA10 putative sequences were annotated. The enzyme showed highest similarity to a glycoside hydrolase family 61 from Chaetomium thermophilum. Recombinant BgAA9 expressed in Pichia pastoris cleaved cellohexaose (DP6) into shorter cellooligosaccharides (DP2, DP3, and DP4). Supplementation BgAA9 to a commercial cellulase, Accellerase® 1500 showed strong synergistic effect on saccharification of Avicel® PH101, decrystallized cellulose, filter paper, and alkaline-pretreated sugarcane bagasse, resulting in 63-93% increase in the total reducing sugar yield after incubation at 50 °C for 72 h. Strong synergism was shown between BgAA9 and the cellulase with the highest total fermentable sugar yield obtained from 75:25% of Accellerase®1500:BgAA9 which released 39 mg glucose/FPU (filter paper unit) equivalent to 38.7% higher than Accellerase®1500 alone at the same total protein dosage of 5 mg/g substrate according to the mixture design study. The enzyme represented the first characterized LPMO from environmental metagenome and a potent auxiliary component for biomass saccharification. KEY POINTS: • BgAA9 represents the first characterized LPMO from metagenome. • 12 AA families were annotated in thermophilic bagasse fosmid library by NGS. • BgAA9 showed homology to Cel61 in Chaetomium thermophilum. • BgAA9 oxidized cellohexaose and PASC to DP2, DP4, and DP6. • BgAA9 showed strong synergism to Accellerase on bagasse hydrolysis.
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Affiliation(s)
- Benjarat Bunterngsook
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Wuttichai Mhuantong
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Pattanop Kanokratana
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand
| | - Yu Iseki
- Laboratory of Biomass Conversion, Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Takashi Watanabe
- Laboratory of Biomass Conversion, Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Verawat Champreda
- Enzyme Technology Laboratory, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathumthani, 12120, Thailand.
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49
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Østby H, Hansen LD, Horn SJ, Eijsink VGH, Várnai A. Enzymatic processing of lignocellulosic biomass: principles, recent advances and perspectives. J Ind Microbiol Biotechnol 2020; 47:623-657. [PMID: 32840713 PMCID: PMC7658087 DOI: 10.1007/s10295-020-02301-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023]
Abstract
Efficient saccharification of lignocellulosic biomass requires concerted development of a pretreatment method, an enzyme cocktail and an enzymatic process, all of which are adapted to the feedstock. Recent years have shown great progress in most aspects of the overall process. In particular, increased insights into the contributions of a wide variety of cellulolytic and hemicellulolytic enzymes have improved the enzymatic processing step and brought down costs. Here, we review major pretreatment technologies and different enzyme process setups and present an in-depth discussion of the various enzyme types that are currently in use. We pay ample attention to the role of the recently discovered lytic polysaccharide monooxygenases (LPMOs), which have led to renewed interest in the role of redox enzyme systems in lignocellulose processing. Better understanding of the interplay between the various enzyme types, as they may occur in a commercial enzyme cocktail, is likely key to further process improvements.
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Affiliation(s)
- Heidi Østby
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Line Degn Hansen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Svein J Horn
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Vincent G H Eijsink
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway
| | - Anikó Várnai
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), P.O. Box 5003, 1432, Aas, Norway.
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