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Chorozian K, Karnaouri A, Tryfona T, Kondyli NG, Karantonis A, Topakas E. Characterization of a novel AA16 lytic polysaccharide monooxygenase from Thermothelomyces thermophilus and comparison of biochemical properties with an LPMO from AA9 family. Carbohydr Polym 2024; 342:122387. [PMID: 39048228 DOI: 10.1016/j.carbpol.2024.122387] [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: 02/21/2024] [Revised: 06/01/2024] [Accepted: 06/07/2024] [Indexed: 07/27/2024]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes which are categorized in the CAZy database under auxiliary activities families AA9-11, 13, 14-17. Secreted by various microorganisms, they play a crucial role in carbon recycling, particularly in fungal saprotrophs. LPMOs oxidize polysaccharides through monooxygenase/peroxygenase activities and exhibit peroxidase and oxidase activities, with variations among different families. AA16, a newly identified LPMO family, is noteworthy due to limited studies on its members, thus rendering the characterization of AA16 enzymes vital for addressing controversies around their functions. This study focused on heterologous expression and biochemical study of an AA16 LPMO from Thermothelomyces thermophilus (formerly known as Myceliophthora thermophila), namely MtLPMO16A. Substrate specificity evaluation of MtLPMO16A showed oxidative cleavage of hemicellulosic substrates and no activity on cellulose, accompanied by a strong oxidase activity. A comparative analysis with an LPMO from AA9 family explored correlations between these families, while MtLPMO16A was shown to boost the activity of some AA9 family LPMOs. The results offer new insights into the AA16 family's action mode and microbial hemicellulose decomposition mechanisms in nature.
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Affiliation(s)
- Koar Chorozian
- Ιndustrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Greece
| | - Anthi Karnaouri
- Laboratory of General and Agricultural Microbiology, Department of Crop Science, Agricultural University of Athens, Athens 11855, Greece.
| | - Theodora Tryfona
- Department of Biochemistry, School of Biological Sciences, University of Cambridge, Cambridge CB2 1QW, UK
| | - Nefeli Georgaki Kondyli
- Ιndustrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Greece; Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15780, Greece
| | - Antonis Karantonis
- Laboratory of Physical Chemistry and Applied Electrochemistry, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15780, Greece
| | - Evangelos Topakas
- Ιndustrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772, Greece.
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Raheja Y, Singh V, Kumar N, Agrawal D, Sharma G, Di Falco M, Tsang A, Chadha BS. Transcriptional and secretome analysis of Rasamsonia emersonii lytic polysaccharide mono-oxygenases. Appl Microbiol Biotechnol 2024; 108:444. [PMID: 39167166 PMCID: PMC11339117 DOI: 10.1007/s00253-024-13240-0] [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: 10/02/2023] [Revised: 06/10/2024] [Accepted: 06/14/2024] [Indexed: 08/23/2024]
Abstract
The current study is the first to describe the temporal and differential transcriptional expression of two lytic polysaccharide monooxygenase (LPMO) genes of Rasamsonia emersonii in response to various carbon sources. The mass spectrometry based secretome analysis of carbohydrate active enzymes (CAZymes) expression in response to different carbon sources showed varying levels of LPMOs (AA9), AA3, AA7, catalase, and superoxide dismutase enzymes pointing toward the redox-interplay between the LPMOs and auxiliary enzymes. Moreover, it was observed that cello-oligosaccharides have a negative impact on the expression of LPMOs, which has not been highlighted in previous reports. The LPMO1 (30 kDa) and LPMO2 (47 kDa), cloned and expressed in Pichia pastoris, were catalytically active with (kcat/Km) of 6.6×10-2 mg-1 ml min-1 and 1.8×10-2 mg-1 ml min-1 against Avicel, respectively. The mass spectrometry of hydrolysis products of Avicel/carboxy methyl cellulose (CMC) showed presence of C1/C4 oxidized oligosaccharides indicating them to be Type 3 LPMOs. The 3D structural analysis of LPMO1 and LPMO2 revealed distinct arrangements of conserved catalytic residues at their active site. The developed enzyme cocktails consisting of cellulase from R. emersonii mutant M36 supplemented with recombinant LPMO1/LPMO2 resulted in significantly enhanced saccharification of steam/acid pretreated unwashed rice straw slurry from PRAJ industries (Pune, India). The current work indicates that LPMO1 and LPMO2 are catalytically efficient and have a high degree of thermostability, emphasizing their usefulness in improving benchmark enzyme cocktail performance. KEY POINTS: • Mass spectrometry depicts subtle interactions between LPMOs and auxiliary enzymes. • Cello-oligosaccharides strongly downregulated the LPMO1 expression. • Developed LPMO cocktails showed superior hydrolysis in comparison to CellicCTec3.
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Affiliation(s)
- Yashika Raheja
- Department of Microbiology, Guru Nanak Dev University, Amritsar-143005, Punjab, India
| | - Varinder Singh
- Department of Microbiology, Guru Nanak Dev University, Amritsar-143005, Punjab, India
| | - Nitish Kumar
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, India
| | - Dhruv Agrawal
- Department of Microbiology, Guru Nanak Dev University, Amritsar-143005, Punjab, India
| | - Gaurav Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar-143005, Punjab, India
| | - Marcos Di Falco
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, H4B 1R6, Canada
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, H4B 1R6, Canada
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Sharma G, Kaur B, Singh V, Raheja Y, Falco MD, Tsang A, Chadha BS. Genome and secretome insights: unravelling the lignocellulolytic potential of Myceliophthora verrucosa for enhanced hydrolysis of lignocellulosic biomass. Arch Microbiol 2024; 206:236. [PMID: 38676717 DOI: 10.1007/s00203-024-03974-w] [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: 02/22/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
Lignocellulolytic enzymes from a novel Myceliophthora verrucosa (5DR) strain was found to potentiate the efficacy of benchmark cellulase during saccharification of acid/alkali treated bagasse by ~ 2.24 fold, indicating it to be an important source of auxiliary enzymes. The De-novo sequencing and analysis of M. verrucosa genome (31.7 Mb) revealed to encode for 7989 putative genes, representing a wide array of CAZymes (366) with a high proportions of auxiliary activity (AA) genes (76). The LC/MS QTOF based secretome analysis of M. verrucosa showed high abundance of glycosyl hydrolases and AA proteins with cellobiose dehydrogenase (CDH) (AA8), being the most prominent auxiliary protein. A gene coding for lytic polysaccharide monooxygenase (LPMO) was expressed in Pichia pastoris and CDH produced by M. verrucosa culture on rice straw based solidified medium were purified and characterized. The mass spectrometry of LPMO catalyzed hydrolytic products of avicel showed the release of both C1/C4 oxidized products, indicating it to be type-3. The lignocellulolytic cocktail comprising of in-house cellulase produced by Aspergillus allahabadii strain spiked with LPMO & CDH exhibited enhanced and better hydrolysis of mild alkali deacetylated (MAD) and unwashed acid pretreated rice straw slurry (UWAP), when compared to Cellic CTec3 at high substrate loading rate.
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Affiliation(s)
- Gaurav Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Varinder Singh
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Yashika Raheja
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, 143005, India
| | - Marcos Di Falco
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
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Raheja Y, Singh V, Sharma G, Tsang A, Chadha BS. A thermostable and inhibitor resistant β-glucosidase from Rasamsonia emersonii for efficient hydrolysis of lignocellulosics biomass. Bioprocess Biosyst Eng 2024; 47:567-582. [PMID: 38470501 DOI: 10.1007/s00449-024-02988-4] [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: 11/06/2023] [Accepted: 02/20/2024] [Indexed: 03/14/2024]
Abstract
The present study reports a highly thermostable β-glucosidase (GH3) from Rasamsonia emersonii that was heterologously expressed in Pichia pastoris. Extracellular β-glucosidase was purified to homogeneity using single step affinity chromatography with molecular weight of ~ 110 kDa. Intriguingly, the purified enzyme displayed high tolerance to inhibitors mainly acetic acid, formic acid, ferulic acid, vanillin and 5-hydroxymethyl furfural at concentrations exceeding those present in acid steam pretreated rice straw slurry used for hydrolysis and subsequent fermentation in 2G ethanol plants. Characteristics of purified β-glucosidase revealed the optimal activity at 80 °C, pH 5.0 and displayed high thermostability over broad range of temperature 50-70 °C with maximum half-life of ~ 60 h at 50 °C, pH 5.0. The putative transglycosylation activity of β-glucosidase was appreciably enhanced in the presence of methanol as an acceptor. Using the transglycosylation ability of β-glucosidase, the generated low cost mixed glucose disaccharides resulted in the increased induction of R. emersonii cellulase under submerged fermentation. Scaling up the recombinant protein production at fermenter level using temporal feeding approach resulted in maximal β-glucosidase titres of 134,660 units/L. Furthermore, a developed custom made enzyme cocktail consisting of cellulase from R. emersonii mutant M36 supplemented with recombinant β-glucosidase resulted in significantly enhanced hydrolysis of pretreated rice straw slurry from IOCL industries (India). Our results suggest multi-faceted β-glucosidase from R. emersonii can overcome obstacles mainly high cost associated enzyme production, inhibitors that impair the sugar yields and thermal inactivation of enzyme.
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Affiliation(s)
- Yashika Raheja
- Department of Microbiology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Varinder Singh
- Department of Microbiology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Gaurav Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India
| | - Adrian Tsang
- Center for Structural and Functional Genomics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
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Chen X, Zhang X, Zhao X, Zhang P, Long L, Ding S. A novel cellulolytic/xylanolytic SbAA14 from Sordaria brevicollis with a branched chain preference and its synergistic effects with glycoside hydrolases on lignocellulose. Int J Biol Macromol 2024; 260:129504. [PMID: 38228212 DOI: 10.1016/j.ijbiomac.2024.129504] [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: 07/25/2023] [Revised: 01/05/2024] [Accepted: 01/12/2024] [Indexed: 01/18/2024]
Abstract
In this study, the novel auxiliary activity (AA) family 14 lytic polysaccharide monooxygenase (LPMO) SbAA14 from Sordaria brevicollis was successfully characterized. It was active against heteroxylan, xyloglucan and cellulose in β-cellulose and released native oligosaccharides and corresponding C1- and/or C4-oxidized products. SbAA14 showed a branched chain preference, because partial removal of arabinosyl substituents from heteroxylan led to a decrease in activity. SbAA14 had synergistic effects with the debranching enzyme EpABF62C in an enzyme- and ascorbic acid-dependent manner. SbAA14 had synergistic effects with the GH10 endoxylanase EpXYN1, and the degree of synergy was greater with step-by-step addition than with simultaneous addition. SbAA14 could also synergize with Celluclast® 1.5 L on NaOH-pretreated wheat straw and on NaOH-pretreated and hydrogen peroxide-acetic acid (HPAC)-H2SO4-pretreated bamboo substrates. The greatest synergistic effect between SbAA14 and Celluclast® 1.5 L was observed for HPAC-H2SO4-200 mM pretreated bamboo, in which the degree of synergy reached approximately 1.61. The distinctive substrate preference of SbAA14 indicated that it is a novel AA14 LPMO that may act mainly on heteroxylan with numerous arabinosyl substituents between cellulose fibers rather than on recalcitrant xylan tightly associated with cellulose. These findings broaden the understanding of enigmatic AA14 LPMOs and provide new insights into the substrate specificities and biological functionalities of AA14 LPMOs in fungi.
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Affiliation(s)
- Xueer 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
| | - 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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Ma L, Wang M, Gao Y, Wu Y, Zhu C, An S, Tang S, She Q, Gao J, Meng X. Functional study of a lytic polysaccharide monooxygenase MsLPMO3 from Morchella sextelata in the oxidative degradation of cellulose. Enzyme Microb Technol 2024; 173:110376. [PMID: 38096655 DOI: 10.1016/j.enzmictec.2023.110376] [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: 07/15/2023] [Revised: 11/09/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) can improve the effectiveness with which agricultural waste is utilized. This study described the potent AA9 family protein MsLPMO3, derived from Morchella sextelata. It exhibited strong binding to phosphoric acid swollen cellulose (PASC), and had the considerable binding ability to Cu2+ with a Kd value of 2.70 μM by isothermal titration calorimetry (ITC). MsLPMO3 could also act on PASC at the C1 carbon via MALDI-TOF-MS results. Moreover, MsLPMO3 could boost the hydrolysis efficiency of corncob and wheat bran in combination with glycoside hydrolases. MsLPMO3 also exhibited strong oxidizing ability for 2,6-dimethoxyphenol (2,6-DMP), achieving the best Vmax value of 443.36 U·g-1 for pH 7.4 with a H2O2 concentration of 300 µM. The structure of MsLPMO3 was obtained using AlphaFold2, and the molecular docking results elucidated the specific interactions and key residues involved in the recognition process between MsLPMO3 and cellulose. Altogether, this study expands the knowledge of AA9 family proteins in cellulose degradation, providing valuable insights into the mechanisms of synergistic degradation of lignocellulose with cellulases.
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Affiliation(s)
- Lei Ma
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Mengmeng Wang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, People's Republic of China
| | - Ya Gao
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Yinghong Wu
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Chaoqiang Zhu
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Shuyu An
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Siyu Tang
- Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, Hunan, People's Republic of China
| | - Qiusheng She
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Jianmin Gao
- College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan 467000, Henan, People's Republic of China
| | - Xiaohui Meng
- Department of Agronomy and Horticulture, Jiangsu Vocational College of Agriculture and Forestry, Jurong 212400, People's Republic of China.
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Dan M, Zheng Y, Zhao G, Hsieh YSY, Wang D. Current insights of factors interfering the stability of lytic polysaccharide monooxygenases. Biotechnol Adv 2023; 67:108216. [PMID: 37473820 DOI: 10.1016/j.biotechadv.2023.108216] [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: 03/20/2023] [Revised: 06/30/2023] [Accepted: 07/16/2023] [Indexed: 07/22/2023]
Abstract
Cellulose and chitin are two of the most abundant biopolymers in nature, but they cannot be effectively utilized in industry due to their recalcitrance. This limitation was overcome by the advent of lytic polysaccharide monooxygenases (LPMOs), which promote the disruption of biopolymers through oxidative mechanism and provide a breakthrough in the action of hydrolytic enzymes. In the application of LPMOs to biomass degradation, the key to consistent and effective functioning lies in their stability. The efficient transformation of biomass resources using LPMOs depends on factors that interfere with their stability. This review discussed three aspects that affect LPMO stability: general external factors, structural factors, and factors in the enzyme-substrate reaction. It explains how these factors impact LPMO stability, discusses the resulting effects, and finally presents relevant measures and considerations, including potential resolutions. The review also provides suggestions for the application of LPMOs in polysaccharide degradation.
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Affiliation(s)
- Meiling Dan
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Yuting Zheng
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Guohua Zhao
- College of Food Science, Southwest University, Chongqing 400715, China
| | - Yves S Y Hsieh
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Centre, 106 91 Stockholm, Sweden; School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan.
| | - Damao Wang
- College of Food Science, Southwest University, Chongqing 400715, China.
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Tõlgo M, Hegnar OA, Larsbrink J, Vilaplana F, Eijsink VGH, Olsson L. Enzymatic debranching is a key determinant of the xylan-degrading activity of family AA9 lytic polysaccharide monooxygenases. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:2. [PMID: 36604763 PMCID: PMC9814446 DOI: 10.1186/s13068-022-02255-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 12/26/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND Previous studies have revealed that some Auxiliary Activity family 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) oxidize and degrade certain types of xylans when incubated with mixtures of xylan and cellulose. Here, we demonstrate that the xylanolytic activities of two xylan-active LPMOs, TtLPMO9E and TtLPMO9G from Thermothielavioides terrestris, strongly depend on the presence of xylan substitutions. RESULTS Using mixtures of phosphoric acid-swollen cellulose (PASC) and wheat arabinoxylan (WAX), we show that removal of arabinosyl substitutions with a GH62 arabinofuranosidase resulted in better adsorption of xylan to cellulose, and enabled LPMO-catalyzed cleavage of this xylan. Furthermore, experiments with mixtures of PASC and arabinoglucuronoxylan from spruce showed that debranching of xylan with the GH62 arabinofuranosidase and a GH115 glucuronidase promoted LPMO activity. Analyses of mixtures with PASC and (non-arabinosylated) beechwood glucuronoxylan showed that GH115 action promoted LPMO activity also on this xylan. Remarkably, when WAX was incubated with Avicel instead of PASC in the presence of the GH62, both xylan and cellulose degradation by the LPMO9 were impaired, showing that the formation of cellulose-xylan complexes and their susceptibility to LPMO action also depend on the properties of the cellulose. These debranching effects not only relate to modulation of the cellulose-xylan interaction, which influences the conformation and rigidity of the xylan, but likely also affect the LPMO-xylan interaction, because debranching changes the architecture of the xylan surface. CONCLUSIONS Our results shed new light on xylanolytic LPMO9 activity and on the functional interplay and possible synergies between the members of complex lignocellulolytic enzyme cocktails. These findings will be relevant for the development of future lignocellulolytic cocktails and biomaterials.
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Affiliation(s)
- Monika Tõlgo
- grid.5371.00000 0001 0775 6028Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden ,grid.5371.00000 0001 0775 6028Wallenberg Wood Science Centre, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Olav A. Hegnar
- grid.19477.3c0000 0004 0607 975XFaculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Johan Larsbrink
- grid.5371.00000 0001 0775 6028Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden ,grid.5371.00000 0001 0775 6028Wallenberg Wood Science Centre, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Francisco Vilaplana
- grid.5037.10000000121581746Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, 106 91 Stockholm, Sweden ,grid.5037.10000000121581746Wallenberg Wood Science Centre, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden
| | - Vincent G. H. Eijsink
- grid.19477.3c0000 0004 0607 975XFaculty of Chemistry, Biotechnology and Food Science, NMBU-Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Lisbeth Olsson
- grid.5371.00000 0001 0775 6028Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden ,grid.5371.00000 0001 0775 6028Wallenberg Wood Science Centre, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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Moon M, Lee JP, Park GW, Lee JS, Park HJ, Min K. Lytic polysaccharide monooxygenase (LPMO)-derived saccharification of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2022; 359:127501. [PMID: 35753567 DOI: 10.1016/j.biortech.2022.127501] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Given that traditional biorefineries have been based on microbial fermentation to produce useful fuels, materials, and chemicals as metabolites, saccharification is an important step to obtain fermentable sugars from biomass. It is well-known that glycosidic hydrolases (GHs) are responsible for the saccharification of recalcitrant polysaccharides through hydrolysis, but the discovery of lytic polysaccharide monooxygenase (LPMO), which is a kind of oxidative enzyme involved in cleaving polysaccharides and boosting GH performance, has profoundly changed the understanding of enzyme-based saccharification. This review briefly introduces the classification, structural information, and catalytic mechanism of LPMOs. In addition to recombinant expression strategies, synergistic effects with GH are comprehensively discussed. Challenges and perspectives for LPMO-based saccharification on a large scale are also briefly mentioned. Ultimately, this review can provide insights for constructing an economically viable lignocellulose-based biorefinery system and a closed-carbon loop to cope with climate change.
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Affiliation(s)
- Myounghoon Moon
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Joon-Pyo Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Gwon Woo Park
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Jin-Suk Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea
| | - Hyun June Park
- Department of Biotechnology, Duksung Women's University, Seoul 01369, Republic of Korea
| | - Kyoungseon Min
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research (KIER), Gwangju 61003, Republic of Korea.
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Li Y, Li T, Guo J, Wang G, Chen G. Expression and characterization of a novel lytic polysaccharide monooxygenase, PdLPMO9A, from the edible fungus Pleurotus djamor and its synergistic interactions with cellulase in corn straw biomass saccharification. BIORESOURCE TECHNOLOGY 2022; 348:126792. [PMID: 35121098 DOI: 10.1016/j.biortech.2022.126792] [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: 12/21/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Lytic polysaccharide monooxygenases play a unique role in biomass saccharification. A novel gene, PdLPMO9A, from Pleurotus djamor, was reported to be upregulated during the degradation of corn straw in our previous research. However, very little information is available on PdLPMO9A. Therefore, PdLPMO9A was heterologously expressed in Pichia pastoris, and biophysical characterisitics of the recombinant protein PdLPMO9A were investigated; it was shown to have superior thermostability and pH stability. PdLPMO9A markedly improved the cellulase-mediated saccharification of corn straw, when the dosage of PdLPMO9A was 0.66 mg/g corn straw and hydrolysis time was 48 h. When CuSO4 was added at a concentration of 0.1 mM, glucose yield rose by a further 28.16%. In light of these findings, it was concluded that PdLPMO9A has the potential to function as an essential component of a cellulase cocktail capable of ensuring the saccharification of corn straw biomass.
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Affiliation(s)
- Yanli Li
- College of Life Science, Jilin Agricultural University, Jilin 130118, China; Key laboratory of straw comprehensive utilization and black soil conservation, Education Ministry of China, Jilin Agricultural University, Jilin 130118, China.
| | - Tongbing Li
- College of Life Science, Jilin Agricultural University, Jilin 130118, China
| | - Juntong Guo
- College of Life Science, Jilin Agricultural University, Jilin 130118, China
| | - Gang Wang
- College of Life Science, Jilin Agricultural University, Jilin 130118, China; Key laboratory of straw comprehensive utilization and black soil conservation, Education Ministry of China, Jilin Agricultural University, Jilin 130118, China
| | - Guang Chen
- College of Life Science, Jilin Agricultural University, Jilin 130118, China; Key laboratory of straw comprehensive utilization and black soil conservation, Education Ministry of China, Jilin Agricultural University, Jilin 130118, China
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11
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Li X, Dilokpimol A, Kabel MA, de Vries RP. Fungal xylanolytic enzymes: Diversity and applications. BIORESOURCE TECHNOLOGY 2022; 344:126290. [PMID: 34748977 DOI: 10.1016/j.biortech.2021.126290] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 05/26/2023]
Abstract
As important polysaccharide degraders in nature, fungi can diversify their extensive set of carbohydrate-active enzymes to survive in ecological habitats of various composition. Among these enzymes, xylanolytic ones can efficiently and sustainably degrade xylans into (fermentable) monosaccharides to produce valuable chemicals or fuels from, for example relevant for upgrading agro-food industrial side streams. Moreover, xylanolytic enzymes are being used in various industrial applications beyond biomass saccharification, e.g. food, animal feed, biofuel, pulp and paper. As a reference for researchers working in related areas, this review summarized the current knowledge on substrate specificity of xylanolytic enzymes from different families of the Carbohydrate-Active enZyme database. Additionally, the diversity of enzyme sets in fungi were discussed by comparing the number of genes encoding xylanolytic enzymes in selected fungal genomes. Finally, to support bio-economy, the current applications of fungal xylanolytic enzymes in industry were reviewed.
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Affiliation(s)
- Xinxin Li
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Adiphol Dilokpimol
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
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12
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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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13
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Rani Singhania R, Dixit P, Kumar Patel A, Shekher Giri B, Kuo CH, Chen CW, Di Dong C. Role and significance of lytic polysaccharide monooxygenases (LPMOs) in lignocellulose deconstruction. BIORESOURCE TECHNOLOGY 2021; 335:125261. [PMID: 34000697 DOI: 10.1016/j.biortech.2021.125261] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 05/27/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) emerged a decade ago and have been described as biomass deconstruction boosters as they play an extremely important role in unravelling the enzymatic biomass hydrolysis scheme. These are oxidative enzymes requiring partners to donate electrons during catalytic action on cellulose backbone. Commercial cellulase preparations are mostly from the robust fungal sources, hence LPMOs from fungi (AA9) have been discussed. Characterisation of LPMOs suffers due to multiple complications which has been discussed and challenges in detection of LPMOs in secretomes has also been highlighted. This review focuses on the significance of LPMOs on biomass hydrolysis due to which it has become a key component of cellulolytic cocktail available commercially for biomass deconstruction and its routine analysis challenge has also been discussed. It has also outlined a few key points that help in expressing catalytic active recombinant AA9 LPMOs.
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Affiliation(s)
- Reeta Rani Singhania
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Pooja Dixit
- Department of Chemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Anil Kumar Patel
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Balendu Shekher Giri
- Department of Chemical Engineering, Indian Institute of Technology, Guwahati 781039 India
| | - Chia-Hung Kuo
- Department of Seafood Science, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Chiu-Wen Chen
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Cheng Di Dong
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
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14
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Ma L, Liu Z, Kong Z, Wang M, Li T, Zhu H, Wan Q, Liu D, Shen Q. Functional characterization of a novel copper-dependent lytic polysaccharide monooxygenase TgAA11 from Trichoderma guizhouense NJAU 4742 in the oxidative degradation of chitin. Carbohydr Polym 2021; 258:117708. [DOI: 10.1016/j.carbpol.2021.117708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/14/2020] [Accepted: 01/22/2021] [Indexed: 01/05/2023]
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15
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Improved strategies to efficiently isolate thermophilic, thermotolerant, and heat-resistant fungi from compost and soil. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01674-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractThermophilic, thermotolerant and heat-resistant fungi developed different physiological traits, enabling them to sustain or even flourish under elevated temperatures, which are life-hostile for most other eukaryotes. With the growing demand of heat-stable molecules in biotechnology and industry, the awareness of heat-adapted fungi as a promising source of respective enzymes and biomolecules is still increasing. The aim of this study was to test two different strategies for the efficient isolation and identification of distinctly heat-adapted fungi from easily accessible substrates and locations. Eight compost piles and ten soil sites were sampled in combination with different culture-dependent approaches to describe suitable strategies for the isolation and selection of thermophilous fungi. Additionally, an approach with a heat-shock treatment, but without elevated temperature incubation led to the isolation of heat-resistant mesophilic species. The cultures were identified based on morphology, DNA barcodes, and microsatellite fingerprinting. In total, 191 obtained isolates were assigned to 31 fungal species, from which half are truly thermophilic or thermotolerant, while the other half are heat-resistant fungi. A numerous amount of heat-adapted fungi was isolated from both compost and soil samples, indicating the suitability of the used approaches and that the richness and availability of those organisms in such environments are substantially high.
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16
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Jawaharraj K, Sudha Dhiman S, Bedwell S, Vemuri B, Islam J, Sani RK, Gadhamshetty V. Electricity from methane by Methylococcus capsulatus (Bath) and Methylosinus trichosporium OB3b. BIORESOURCE TECHNOLOGY 2021; 321:124398. [PMID: 33257167 DOI: 10.1016/j.biortech.2020.124398] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/31/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Given the difficulties valorizing methane (CH4) via catalytic routes, this study explores use of CH4-oxidizing bacteria ("methanotrophs") for generating electricity directly from CH4. A preconditioned methanotrophic biofilm on 3D nickel foam with reduced graphene oxide (rGO/Ni) was used as the anode in two-compartment microbial fuel cells (MFCs). This study demonstrates a proof of concept for turning CH4 into electricity by two model methanotrophs including Methylosinus trichosposium OB3b and Methylococcus capsulatus (Bath). Both OB3b (205 mW.m-2) and Bath (110 mW.m-2) strains yielded a higher electricity from CH4 when grown on rGO/Ni compared to graphite felt electrodes. Based on electrochemistry tests, molecular dynamics simulations, genome annotations and interaction analysis, a mechanistic understanding of reasons behind enhanced performance of methanotrophs grown on rGO/Ni are presented.
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Affiliation(s)
- Kalimuthu Jawaharraj
- Department of Civil and Environmental Engineering, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; BuG ReMeDEE Consortia, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; 2D-materials for Biofilm Engineering, Science and Technology (2DBEST) Center, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD 57701, USA
| | - Saurabh Sudha Dhiman
- BuG ReMeDEE Consortia, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; Chemical and Biological Engineering, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD 57701, USA; 2D-materials for Biofilm Engineering, Science and Technology (2DBEST) Center, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD 57701, USA
| | - Sierra Bedwell
- Department of Microbiology and Immunology, Montana State University, Culbertson Hall, 100, Bozeman, MT 59717, USA
| | - Bhuvan Vemuri
- Department of Civil and Environmental Engineering, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; BuG ReMeDEE Consortia, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA
| | - Jamil Islam
- Department of Civil and Environmental Engineering, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; BuG ReMeDEE Consortia, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA
| | - Rajesh Kumar Sani
- BuG ReMeDEE Consortia, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; Chemical and Biological Engineering, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD 57701, USA; 2D-materials for Biofilm Engineering, Science and Technology (2DBEST) Center, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD 57701, USA
| | - Venkataramana Gadhamshetty
- Department of Civil and Environmental Engineering, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; BuG ReMeDEE Consortia, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD, USA; 2D-materials for Biofilm Engineering, Science and Technology (2DBEST) Center, South Dakota Mines, 501 E. St. Joseph Street, Rapid City, SD 57701, USA.
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17
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Frandsen KEH, Haon M, Grisel S, Henrissat B, Lo Leggio L, Berrin JG. Identification of the molecular determinants driving the substrate specificity of fungal lytic polysaccharide monooxygenases (LPMOs). J Biol Chem 2021; 296:100086. [PMID: 33199373 PMCID: PMC7949027 DOI: 10.1074/jbc.ra120.015545] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 01/30/2023] Open
Abstract
Understanding enzymatic breakdown of plant biomass is crucial to develop nature-inspired biotechnological processes. Lytic polysaccharide monooxygenases (LPMOs) are microbial enzymes secreted by fungal saprotrophs involved in carbon recycling. LPMOs modify biomass by oxidatively cleaving polysaccharides, thereby enhancing the efficiency of glycoside hydrolases. Fungal AA9 LPMOs are active on cellulose, but some members also display activity on hemicelluloses and/or oligosaccharides. Although the active site subsites are well defined for a few model LPMOs, the molecular determinants driving broad substrate specificity are still not easily predictable. Based on bioinformatic clustering and sequence alignments, we selected seven fungal AA9 LPMOs that differ in the amino-acid residues constituting their subsites. Investigation of their substrate specificities revealed that all these LPMOs are active on cellulose and cello-oligosaccharides, as well as plant cell wall-derived hemicellulosic polysaccharides, and carry out C4 oxidative cleavage. The product profiles from cello-oligosaccharide degradation suggest that the subtle differences in amino-acid sequence within the substrate-binding loop regions lead to different preferred binding modes. Our functional analyses allowed us to probe the molecular determinants of substrate binding within two AA9 LPMO subclusters. Many wood-degrading fungal species rich in AA9 genes have at least one AA9 enzyme with structural loop features that allow recognition of short β-(1,4)-linked glucan chains. Time-course monitoring of these AA9 LPMOs on cello-oligosaccharides also provides a useful model system for mechanistic studies of LPMO catalysis. These results are valuable for the understanding of LPMO contribution to wood decaying process in nature and for the development of sustainable biorefineries.
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Affiliation(s)
- Kristian E H Frandsen
- INRAE, Aix-Marseille University, Polytech Marseille, UMR1163 BBF, Marseille, France; Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Mireille Haon
- INRAE, Aix-Marseille University, Polytech Marseille, UMR1163 BBF, Marseille, France
| | - Sacha Grisel
- INRAE, Aix-Marseille University, Polytech Marseille, UMR1163 BBF, Marseille, France
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix-Marseille Université, Marseille, France; INRAE, USC1408 Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France; Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Leila Lo Leggio
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Jean-Guy Berrin
- INRAE, Aix-Marseille University, Polytech Marseille, UMR1163 BBF, Marseille, France.
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18
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Improving the fermentable sugar yields of wheat straw by high-temperature pre-hydrolysis with thermophilic enzymes of Malbranchea cinnamomea. Microb Cell Fact 2020; 19:149. [PMID: 32711527 PMCID: PMC7382850 DOI: 10.1186/s12934-020-01408-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 07/20/2020] [Indexed: 12/23/2022] Open
Abstract
Background Enzymatic hydrolysis is a key step in the conversion of lignocellulosic polysaccharides to fermentable sugars for the production of biofuels and high-value chemicals. However, current enzyme preparations from mesophilic fungi are deficient in their thermostability and biomass-hydrolyzing efficiency at high temperatures. Thermophilic fungi represent promising sources of thermostable and highly active enzymes for improving the biomass-to-sugar conversion process. Here we present a comprehensive study on the lignocellulosic biomass-degrading ability and enzyme system of thermophilic fungus Malbranchea cinnamomea N12 and the application of its enzymes in the synergistic hydrolysis of lignocellulosic biomass. Results Malbranchea cinnamomea N12 was capable of utilizing untreated wheat straw to produce high levels of xylanases and efficiently degrading lignocellulose under thermophilic conditions. Temporal analysis of the wheat straw-induced secretome revealed that M. cinnamomea N12 successively degraded the lignocellulosic polysaccharides through sequential secretion of enzymes targeting xylan and cellulose. Xylanase-enriched cocktail from M. cinnamomea N12 was more active on native and alkali‑pretreated wheat straw than the commercial xylanases from Trichoderma reesei over temperatures ranging from 40 to 75 °C. Integration of M. cinnamomea N12 enzymes with the commercial cellulase preparation increased the glucose and xylose yields of alkali‑pretreated wheat straw by 32 and 166%, respectively, with pronounced effects at elevated temperature. Conclusions This study demonstrated the remarkable xylanase-producing ability and strategy of sequential lignocellulose breakdown of M. cinnamomea N12. A new process for the hydrolysis of lignocellulosic biomass was proposed, comprising thermophilic enzymolysis by enzymes of M. cinnamomea N12 followed with mesophilic enzymolysis by commercial cellulases. Developing M. cinnamomea N12 as platforms for thermophilic enzyme mixture production will provide new perspectives for improved conversion yields for current biomass saccharification schemes.
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19
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Limsakul P, Phitsuwan P, Waeonukul R, Pason P, Tachaapaikoon C, Poomputsa K, Kosugi A, Sakka M, Sakka K, Ratanakhanokchai K. A novel AA10 from Paenibacillus curdlanolyticus and its synergistic action on crystalline and complex polysaccharides. Appl Microbiol Biotechnol 2020; 104:7533-7550. [PMID: 32651597 DOI: 10.1007/s00253-020-10758-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/18/2020] [Accepted: 06/24/2020] [Indexed: 02/08/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) play an important role in the degradation of complex polysaccharides in lignocellulosic biomass. In the present study, we characterized a modular LPMO (PcAA10A), consisting of a family 10 auxiliary activity of LPMO (AA10) catalytic domain, and non-catalytic domains including a family 5 carbohydrate-binding module, two fibronectin type-3 domains, and a family 3 carbohydrate-binding module from Paenibacillus curdlanolyticus B-6, which was expressed in a recombinant Escherichia coli. Comparison of activities between full-length PcAA10A and the catalytic domain polypeptide (PcAA10A_CD) indicates that the non-catalytic domains are important for the deconstruction of crystalline cellulose and complex polysaccharides contained in untreated lignocellulosic biomass. Interestingly, PcAA10A_CD acted not only on cellulose and chitin, but also on xylan, mannan, and xylan and cellulose contained in lignocellulosic biomass, which has not been reported for the AA10 family. Mutation of the key residues, Trp51 located at subsite - 2 and Phe171 located at subsite +2, in the substrate-binding site of PcAA10A_CD revealed that these residues are substantially involved in broad substrate specificity toward cellulose, xylan, and mannan, albeit with a low effect toward chitin. Furthermore, PcAA10A had a boosting effect on untreated corn hull degradation by P. curdlanolyticus B-6 endo-xylanase Xyn10D and Clostridium thermocellum endo-glucanase Cel9A. These results suggest that PcAA10A is a unique LPMO capable of cleaving and enhancing lignocellulosic biomass degradation, making it a good candidate for biotechnological applications. KEY POINTS: • PcAA10A is a novel modular LPMO family 10 from Paenibacillus curdlanolyticus. • PcAA10A showed broad substrate specificity on β-1,4 glycosidic linkage substrates. • Non-catalytic domains are important for degrading complex polysaccharides. • PcAA10A is a unique LPMO capable of enhancing lignocellulosic biomass degradation.
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Affiliation(s)
- Puangpen Limsakul
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Paripok Phitsuwan
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Rattiya Waeonukul
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Patthra Pason
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Chakrit Tachaapaikoon
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Kanokwan Poomputsa
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand
| | - Akihiko Kosugi
- Biological Resources and Post-harvest Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, 305-8686, Japan
| | - Makiko Sakka
- Graduated School of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan
| | - Kazuo Sakka
- Graduated School of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan.
| | - Khanok Ratanakhanokchai
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, 10150, Thailand.
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20
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Agrawal D, Kaur B, Kaur Brar K, Chadha BS. An innovative approach of priming lignocellulosics with lytic polysaccharide mono-oxygenases prior to saccharification with glycosyl hydrolases can economize second generation ethanol process. BIORESOURCE TECHNOLOGY 2020; 308:123257. [PMID: 32244131 DOI: 10.1016/j.biortech.2020.123257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Two Lytic polysaccharide Mono-Oxygenases (LPMOs), non-modular (PMO_08942) and modular (PMO_07920), from thermotolerant fungus Aspergillus terreus 9DR cloned and expressed in Pichia pastoris X33 and purified to homogeneity using ion-exchange chromatography were found to be of ~29 and ~40 kDa, respectively. Both LPMOs were optimally active at 50 °C; PMO_08942 was active under acidic condition (pH 5.0) and PMO_07920 at pH 7.0. Modular LPMO (PMO_07920) tethered to CBM-1 was found to be versatile as it showed appreciable activity on complex polysaccharide (both cellulose and xylans) as compared to non-modular (PMO_08942). The t1/2 of PMO_08942 (~192 h, pH 5.0) and PMO_0792 (~192 h, pH 7.0) at 50 °C, suggests highly stable nature of these LPMOs. Fluorescently tagged modular AA9 was studied microscopically to understand interaction with pretreated biomass. Priming of biomass for up to 6 h with LPMOs prior to initiating hydrolysis with core cellulase enzyme resulted in significantly higher saccharification.
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Affiliation(s)
- Dhruv Agrawal
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab 143005, India
| | - Baljit Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab 143005, India
| | - Kamalpreet Kaur Brar
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab 143005, India
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21
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Zhang R. Functional characterization of cellulose-degrading AA9 lytic polysaccharide monooxygenases and their potential exploitation. Appl Microbiol Biotechnol 2020; 104:3229-3243. [PMID: 32076777 DOI: 10.1007/s00253-020-10467-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 12/25/2019] [Accepted: 02/12/2020] [Indexed: 01/05/2023]
Abstract
Cellulose-degrading auxiliary activity family 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) are known to be widely distributed among filamentous fungi and participate in the degradation of lignocellulose via the oxidative cleavage of celluloses, cello-oligosaccharides, or hemicelluloses. AA9 LPMOs have been reported to have extensive interactions with not only cellulases but also oxidases. The addition of AA9 LPMOs can greatly reduce the amount of cellulase needed for saccharification and increase the yield of glucose. The discovery of AA9 LPMOs has greatly changed our understanding of how fungi degrade cellulose. In this review, apart from summarizing the recent discoveries related to their catalytic reaction, functional diversity, and practical applications, the stability, expression system, and protein engineering of AA9 LPMOs are reviewed for the first time. This review may provide a reference value to further broaden the substrate range of AA9 LPMOs, expand the scope of their practical applications, and realize their customization for industrial utilization.Key Points• The stability and expression system of AA9 LPMOs are reviewed for the first time.• The protein engineering of AA9 LPMOs is systematically summarized for the first time.• The latest research results on the catalytic mechanism of AA9 LPMOs are summarized.• The application of AA9 LPMOs and their relationship with other enzymes are reviewed.
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Affiliation(s)
- Ruiqin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, No. 72 Binhai Road, Qingdao, 266237, China.
- Department of Bioengineering, Huainan Normal University, No. 278 Xueyuannan Road, Huainan, 232038, China.
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Zerva A, Pentari C, Grisel S, Berrin JG, Topakas E. A new synergistic relationship between xylan-active LPMO and xylobiohydrolase to tackle recalcitrant xylan. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:142. [PMID: 32793303 PMCID: PMC7419196 DOI: 10.1186/s13068-020-01777-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/29/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND Hemicellulose accounts for a significant part of plant biomass, and still poses a barrier to the efficient saccharification of lignocellulose. The recalcitrant part of hemicellulose is a serious impediment to the action of cellulases, despite the use of xylanases in the cellulolytic cocktail mixtures. However, the complexity and variety of hemicelluloses in different plant materials require the use of highly specific enzymes for a complete breakdown. Over the last few years, new fungal enzymes with novel activities on hemicelluloses have emerged. In the present study, we explored the synergistic relationships of the xylan-active AA14 lytic polysaccharide monooxygenase (LPMO), PcAA14B, with the recently discovered glucuronoxylan-specific xylanase TtXyn30A, of the (sub)family GH30_7, displaying xylobiohydrolase activity, and with commercial cellobiohydrolases, on pretreated natural lignocellulosic substrates. RESULTS PcAA14B and TtXyn30A showed a strong synergistic interaction on the degradation of the recalcitrant part of xylan. PcAA14B was able to increase the release of xylobiose from TtXyn30A, showing a degree of synergism (DS) of 3.8 on birchwood cellulosic fibers, and up to 5.7 on pretreated beechwood substrates. The increase in activity was dose- and time- dependent. A screening study on beechwood materials pretreated with different methods showed that the effect of the PcAA14B-TtXyn30A synergism was more prominent on substrates with low hemicellulose content, indicating that PcAA14B is mainly active on the recalcitrant part of xylan, which is in close proximity to the underlying cellulose fibers. Simultaneous addition of both enzymes resulted in higher DS than sequential addition. Moreover, PcAA14B was found to enhance cellobiose release from cellobiohydrolases during hydrolysis of pretreated lignocellulosic substrates, as well as microcrystalline cellulose. CONCLUSIONS The results of the present study revealed a new synergistic relationship not only among two recently discovered xylan-active enzymes, the LPMO PcAA14B, and the GH30_7 glucuronoxylan-active xylobiohydrolase TtXyn30A, but also among PcAA14B and cellobiohydrolases. We hypothesize that PcAA14B creates free ends in the xylan polymer, which can be used as targets for the action of TtXyn30A. The results are of special importance for the design of next-generation enzymatic cocktails, able to efficiently remove hemicelluloses, allowing complete saccharification of cellulose in plant biomass.
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Affiliation(s)
- Anastasia Zerva
- Industrial Biotechnology and Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
- INRAE, Aix Marseille University, Biodiversité Et Biotechnologie Fongiques (BBF), UMR1163, 13009 Marseille, France
| | - Christina Pentari
- Industrial Biotechnology and Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
| | - Sacha Grisel
- INRAE, Aix Marseille University, Biodiversité Et Biotechnologie Fongiques (BBF), UMR1163, 13009 Marseille, France
| | - Jean-Guy Berrin
- INRAE, Aix Marseille University, Biodiversité Et Biotechnologie Fongiques (BBF), UMR1163, 13009 Marseille, France
| | - Evangelos Topakas
- Industrial Biotechnology and Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780 Athens, Greece
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Discovery and Expression of Thermostable LPMOs from Thermophilic Fungi for Producing Efficient Lignocellulolytic Enzyme Cocktails. Appl Biochem Biotechnol 2019; 191:463-481. [DOI: 10.1007/s12010-019-03198-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/23/2019] [Indexed: 01/18/2023]
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Specific Xylan Activity Revealed for AA9 Lytic Polysaccharide Monooxygenases of the Thermophilic Fungus Malbranchea cinnamomea by Functional Characterization. Appl Environ Microbiol 2019; 85:AEM.01408-19. [PMID: 31540984 PMCID: PMC6856335 DOI: 10.1128/aem.01408-19] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/14/2019] [Indexed: 11/20/2022] Open
Abstract
The thermophilic biomass-degrader Malbranchea cinnamomea exhibits poor growth on cellulose but excellent growth on hemicelluloses as the sole carbon source. This is surprising considering that its genome encodes eight lytic polysaccharide monooxygenases (LPMOs) from auxiliary activity family 9 (AA9), enzymes known for their high potential in accelerating cellulose depolymerization. We characterized four of the eight (M. cinnamomea AA9s) McAA9s, namely, McAA9A, McAA9B, McAA9F, and McAA9H, to gain a deeper understanding about their roles in the fungus. The characterized McAA9s were active on hemicelluloses, including xylan, glucomannan, and xyloglucan, and furthermore, in accordance with transcriptomics data, differed in substrate specificity. Of the McAA9s, McAA9H is unique, as it preferentially cleaves residual xylan in phosphoric acid-swollen cellulose (PASC). Moreover, when exposed to cellulose-xylan blends, McAA9H shows a preference for xylan and for releasing (oxidized) xylooligosaccharides. The cellulose dependence of the xylan activity suggests that a flat conformation, with rigidity similar to that of cellulose microfibrils, is a prerequisite for productive interaction between xylan and the catalytic surface of the LPMO. McAA9H showed a similar trend on xyloglucan, underpinning the suggestion that LPMO activity on hemicelluloses strongly depends on the polymers' physicochemical context and conformation. Our results support the notion that LPMO multiplicity in fungal genomes relates to the large variety of copolymeric polysaccharide arrangements occurring in the plant cell wall.IMPORTANCE The Malbranchea cinnamomea LPMOs (McAA9s) showed activity on a broad range of soluble and insoluble substrates, suggesting their involvement in various steps of biomass degradation besides cellulose decomposition. Our results indicate that the fungal AA9 family is more diverse than originally thought and able to degrade almost any kind of plant cell wall polysaccharide. The discovery of an AA9 that preferentially cleaves xylan enhances our understanding of the physiological roles of LPMOs and enables the use of xylan-specific LPMOs in future applications.
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