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Akram F, Fatima T, Ibrar R, Shabbir I, Shah FI, Haq IU. Trends in the development and current perspective of thermostable bacterial hemicellulases with their industrial endeavors: A review. Int J Biol Macromol 2024; 265:130993. [PMID: 38508567 DOI: 10.1016/j.ijbiomac.2024.130993] [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: 07/15/2023] [Revised: 03/12/2024] [Accepted: 03/17/2024] [Indexed: 03/22/2024]
Abstract
Hemicellulases are enzymes that hydrolyze hemicelluloses, common polysaccharides in nature. Thermophilic hemicellulases, derived from microbial strains, are extensively studied as natural biofuel sources due to the complex structure of hemicelluloses. Recent research aims to elucidate the catalytic principles, mechanisms and specificity of hemicellulases through investigations into their high-temperature stability and structural features, which have applications in biotechnology and industry. This review article targets to serve as a comprehensive resource, highlighting the significant progress in the field and emphasizing the vital role of thermophilic hemicellulases in eco-friendly catalysis. The primary goal is to improve the reliability of hemicellulase enzymes obtained from thermophilic bacterial strains. Additionally, with their ability to break down lignocellulosic materials, hemicellulases hold immense potential for biofuel production. Despite their potential, the commercial viability is hindered by their high enzyme costs, necessitating the development of efficient bioprocesses involving waste pretreatment with microbial consortia to overcome this challenge.
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Affiliation(s)
- Fatima Akram
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan.
| | - Taseer Fatima
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Ramesha Ibrar
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Ifrah Shabbir
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | | | - Ikram Ul Haq
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan; Pakistan Academy of Sciences, Islamabad, Pakistan
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2
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Ha NS, Onley JR, Deng K, Andeer P, Bowen BP, Gupta K, Kim PW, Kuch N, Kutschke M, Parker A, Song F, Fox B, Adams PD, de Raad M, Northen TR. A combinatorial droplet microfluidic device integrated with mass spectrometry for enzyme screening. LAB ON A CHIP 2023; 23:3361-3369. [PMID: 37401915 PMCID: PMC10484474 DOI: 10.1039/d2lc00980c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Mass spectrometry (MS) enables detection of different chemical species with a very high specificity; however, it can be limited by its throughput. Integrating MS with microfluidics has a tremendous potential to improve throughput and accelerate biochemical research. In this work, we introduce Drop-NIMS, a combination of a passive droplet loading microfluidic device and a matrix-free MS laser desorption ionization technique called nanostructure-initiator mass spectrometry (NIMS). This platform combines different droplets at random to generate a combinatorial library of enzymatic reactions that are deposited directly on the NIMS surface without requiring additional sample handling. The enzyme reaction products are then detected with MS. Drop-NIMS was used to rapidly screen enzymatic reactions containing low (on the order of nL) volumes of glycoside reactants and glycoside hydrolase enzymes per reaction. MS "barcodes" (small compounds with unique masses) were added to the droplets to identify different combinations of substrates and enzymes created by the device. We assigned xylanase activities to several putative glycoside hydrolases, making them relevant to food and biofuel industrial applications. Overall, Drop-NIMS is simple to fabricate, assemble, and operate and it has potential to be used with many other small molecule metabolites.
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Affiliation(s)
- Noel S Ha
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jenny R Onley
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Sandia National Laboratories, Livermore, California, USA
| | - Kai Deng
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Sandia National Laboratories, Livermore, California, USA
| | - Peter Andeer
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Kshitiz Gupta
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Peter W Kim
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Sandia National Laboratories, Livermore, California, USA
| | - Nathaniel Kuch
- University of Wisconsin - Madison, Madison, WI, USA
- Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, WI, USA
| | | | - Alex Parker
- University of Wisconsin - Madison, Madison, WI, USA
| | - Fangchao Song
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Brian Fox
- University of Wisconsin - Madison, Madison, WI, USA
- Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Madison, WI, USA
| | - Paul D Adams
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- University of California, Berkeley, CA, USA
| | - Markus de Raad
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Trent R Northen
- Joint BioEnergy Institute, Emeryville, CA, USA.
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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Paul M, Pandey NK, Banerjee A, Shroti GK, Tomer P, Gazara RK, Thatoi H, Bhaskar T, Hazra S, Ghosh D. An insight into omics analysis and metabolic pathway engineering of lignin-degrading enzymes for enhanced lignin valorization. BIORESOURCE TECHNOLOGY 2023; 379:129045. [PMID: 37044152 DOI: 10.1016/j.biortech.2023.129045] [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: 01/31/2023] [Revised: 04/06/2023] [Accepted: 04/09/2023] [Indexed: 05/03/2023]
Abstract
Lignin, a highly heterogeneous polymer of lignocellulosic biomass, is intricately associated with cellulose and hemicellulose, responsible for its strength and rigidity. Lignin decomposition is carried out through certain enzymes derived from microorganisms to promote the hydrolysis of lignin. Analyzing multi-omics data helps to emphasize the probable value of fungal-produced enzymes to degrade the lignocellulosic material, which provides them an advantage in their ecological niches. This review focuses on lignin biodegrading microorganisms and associated ligninolytic enzymes, including lignin peroxidase, manganese peroxidase, versatile peroxidase, laccase, and dye-decolorizing peroxidase. Further, enzymatic catalysis, lignin biodegradation mechanisms, vital factors responsible for lignin modification and degradation, and the design and selection of practical metabolic pathways are also discussed. Highlights were made on metabolic pathway engineering, different aspects of omics analyses, and its scope and applications to ligninase enzymes. Finally, the advantages and essential steps of successfully applying metabolic engineering and its path forward have been addressed.
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Affiliation(s)
- Manish Paul
- Department of Biotechnology, Maharaja Sriram Chandra Bhanja Deo University, Takatpur, Baripada, Odisha 757003, India
| | - Niteesh Kumar Pandey
- Department of Bioscience and Bioengineering, Indian Institute of Technology-Roorkee, Roorkee, Uttarakhand 247667, India
| | - Ayan Banerjee
- Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Mohkampur, Dehradun, Uttarakhand 248005, India; Academy of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
| | - Gireesh Kumar Shroti
- Department of Bioscience and Bioengineering, Indian Institute of Technology-Roorkee, Roorkee, Uttarakhand 247667, India
| | - Preeti Tomer
- Department of Bioscience and Bioengineering, Indian Institute of Technology-Roorkee, Roorkee, Uttarakhand 247667, India
| | - Rajesh Kumar Gazara
- Department of Bioscience and Bioengineering, Indian Institute of Technology-Roorkee, Roorkee, Uttarakhand 247667, India
| | - Hrudayanath Thatoi
- Department of Biotechnology, Maharaja Sriram Chandra Bhanja Deo University, Takatpur, Baripada, Odisha 757003, India
| | - Thallada Bhaskar
- Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Mohkampur, Dehradun, Uttarakhand 248005, India; Academy of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
| | - Saugata Hazra
- Department of Bioscience and Bioengineering, Indian Institute of Technology-Roorkee, Roorkee, Uttarakhand 247667, India; Centre for Nanotechnology, Indian Institute of Technology-Roorkee, Roorkee, Uttarakhand 247667, India.
| | - Debashish Ghosh
- Material Resource Efficiency Division, CSIR-Indian Institute of Petroleum, Mohkampur, Dehradun, Uttarakhand 248005, India; Academy of Scientific and Innovative Research, CSIR-HRDC Campus, Ghaziabad, Uttar Pradesh 201002, India
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4
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Zhou R, Zhang L, Zeng B, Zhou Y, Jin W, Zhang G. A novel self-purified auxiliary protein enhances the lichenase activity towards lichenan for biomass degradation. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12608-y. [PMID: 37272940 DOI: 10.1007/s00253-023-12608-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/06/2023]
Abstract
Due to the complex composition of lichenan, lichenase alone cannot always hydrolyze it efficiently. Carbohydrate-binding modules (CBMs) and lytic polysaccharide monooxygenases (LPMOs) have been confirmed to increase the hydrolysis efficiency of lichenases. However, their practical application was hampered by the complex and costly preparation procedure, as well as the poor stability of LPMOs. Herein, we discovered a novel and stable auxiliary protein named SCE to boost the hydrolysis efficiency. SCE was composed of SpyCatcher (SC) and elastin-like polypeptides (ELPs) and could be easily and cheaply prepared. Under the optimal conditions, the boosting degree for SCE/lichenase was 1.45, and the reducing sugar yield improved by nearly 45%. The results of high-performance liquid chromatography (HPLC) indicated that SCE had no influence on the hydrolysis pattern of lichenase. Through the experimental verification and bioinformatics analysis, we proposed the role of SCE in promoting the interaction between the lichenase and substrates. These findings endow SC with a novel function in binding to insoluble lichenan, paving the way for biomass degradation and biorefinery. KEY POINTS: • A novel self-purification auxiliary protein that could boost the hydrolysis efficiency of lichenase has been identified. • The protein is highly produced, simple to prepare, well stable, and does not require any external electron donor. • The novel function of SpyCatcher in binding to insoluble lichenan was first demonstrated.
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Affiliation(s)
- Rui Zhou
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Lingzhi Zhang
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Bo Zeng
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Yanhong Zhou
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China
| | - Wenhui Jin
- Technology Innovation Center for Exploitation of Marine Biological Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, Fujian Province, People's Republic of China
| | - Guangya Zhang
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian Province, People's Republic of China.
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Liu Y, Ran Q, Guo J, Zhu W, Bushra R, Duan X, Huang Y, Jiang Z, Khan MR, Jin Y, Xiao H, Song J. In-situ CBM3-modified bacterial cellulose film with improved mechanical properties. Int J Biol Macromol 2023:125193. [PMID: 37285886 DOI: 10.1016/j.ijbiomac.2023.125193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 04/19/2023] [Accepted: 05/31/2023] [Indexed: 06/09/2023]
Abstract
Cellulose materials have poor wet strength and are susceptible to acidic or basic environments. Herein, we developed a facile strategy to modify bacterial cellulose (BC) with a genetically engineered Family 3 Carbohydrate-Binding Module (CBM3). To assess the effect of BC films, water adsorption rate (WAR), water holding capacity (WHC), water contact angle (WCA), and mechanical and barrier properties were determined. The results showed that CBM3-modified BC film exhibited significant strength and ductility improvement, reflecting improved mechanical properties of the film. The excellent wet strength (both in the acidic and basic environment), bursting strength, and folding endurance of CBM3-BC films were due to the strong interaction between CBM3 and fiber. The toughness of CBM3-BC films reached 7.9, 28.0, 13.3, and 13.6 MJ/m3, which were 6.1, 1.3, 1.4, and 3.0 folds over the control for conditions of dry, wet, acidic, and basic, respectively. In addition, its gas permeability was reduced by 74.3 %, and folding times increased by 56.8 % compared with the control. The synthesized CBM3-BC films may hold promise for future applications in food packaging, paper straw, battery separator, and other fields. Finally, the in situ modification strategy used to BC can be successfully applied in other functional modifications for BC materials.
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Affiliation(s)
- Yena Liu
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Qiuping Ran
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, China
| | - Jiaqi Guo
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Wenyuan Zhu
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Rani Bushra
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China
| | - Xuguo Duan
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Yang Huang
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Zhengbing Jiang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, China.
| | - Mohammad R Khan
- Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Yongcan Jin
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
| | - Huining Xiao
- Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.
| | - Junlong Song
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
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Kuch NJ, Kutschke ME, Parker A, Bingman CA, Fox BG. Contribution of calcium ligands in substrate binding and product release in the Acetovibrio thermocellus glycoside hydrolase family 9 cellulase CelR. J Biol Chem 2023; 299:104655. [PMID: 36990218 PMCID: PMC10149213 DOI: 10.1016/j.jbc.2023.104655] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Enzymatic deconstruction of lignocellulosic biomass is crucial to establishment of the renewable biofuel and bioproduct economy. Better understanding of these enzymes, including their catalytic and binding domains, and other features offer potential avenues for improvement. Glycoside hydrolase family 9 (GH9) enzymes are attractive targets because they have members that exhibit exo- and endo-cellulolytic activity, processivity of reaction, and thermostability. This study examines a GH9 from Acetovibrio thermocellus ATCC 27405, AtCelR containing a catalytic domain and a carbohydrate binding module (CBM3c). Crystal structures of the enzyme without substrate, bound to cellohexaose (substrate) or cellobiose (product), show the positioning of ligands to calcium and adjacent residues in the catalytic domain that may contribute to substrate binding and facilitate product release. We also investigated the properties of the enzyme engineered to contain an additional carbohydrate binding module (CBM3a). Relative to the catalytic domain alone, CBM3a gave improved binding for Avicel (a crystalline form of cellulose), and catalytic efficiency (kcat/KM) was improved 40× with both CBM3c and CBM3a present. However, because of the molecular weight added by CBM3a, the specific activity of the engineered enzyme was not increased relative to the native construct consisting of only the catalytic and CBM3c domains. This work provides new insight into a potential role of the conserved calcium in the catalytic domain and identifies contributions and limitations of domain engineering for AtCelR and perhaps other GH9 enzymes.
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Affiliation(s)
- Nathaniel J Kuch
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mark E Kutschke
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alex Parker
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA; Dane County Youth Apprenticeship Program, Dane County School Consortium, Monona, Wisconsin, USA
| | - Craig A Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA; Collaborative Crystallography Core, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Brian G Fox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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Shi Q, Abdel-Hamid AM, Sun Z, Cheng Y, Tu T, Cann I, Yao B, Zhu W. Carbohydrate-binding modules facilitate the enzymatic hydrolysis of lignocellulosic biomass: Releasing reducing sugars and dissociative lignin available for producing biofuels and chemicals. Biotechnol Adv 2023; 65:108126. [PMID: 36921877 DOI: 10.1016/j.biotechadv.2023.108126] [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: 11/18/2022] [Revised: 02/05/2023] [Accepted: 03/08/2023] [Indexed: 03/16/2023]
Abstract
The microbial decomposition and utilization of lignocellulosic biomass present in the plant tissues are driven by a series of carbohydrate active enzymes (CAZymes) acting in concert. As the non-catalytic domains widely found in the modular CAZymes, carbohydrate-binding modules (CBMs) are intimately associated with catalytic domains (CDs) that effect the diverse hydrolytic reactions. The CBMs function as auxiliary components for the recognition, adhesion, and depolymerization of the complex substrate mediated by the associated CDs. Therefore, CBMs are deemed as significant biotools available for enzyme engineering, especially to facilitate the enzymatic hydrolysis of dense and insoluble plant tissues to acquire more fermentable sugars. This review aims at presenting the taxonomies and biological properties of the CBMs currently curated in the CAZy database. The molecular mechanisms that CBMs use in assisting the enzymatic hydrolysis of plant polysaccharides and the regulatory factors of CBM-substrate interactions are outlined in detail. In addition, guidelines for the rational designs of CBM-fused CAZymes are proposed. Furthermore, the potential to harness CBMs for industrial applications, especially in enzymatic pretreatment of the recalcitrant lignocellulose, is evaluated. It is envisaged that the ideas outlined herein will aid in the engineering and production of novel CBM-fused enzymes to facilitate efficient degradation of lignocellulosic biomass to easily fermentable sugars for production of value-added products, including biofuels.
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Affiliation(s)
- Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Ahmed M Abdel-Hamid
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, IL 61801, USA
| | - Zhanying Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China.
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Isaac Cann
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, IL 61801, USA; Department of Animal Science, University of Illinois at Urbana-Champaign, IL 61801, USA; Department of Microbiology, University of Illinois at Urbana-Champaign, IL 61801, USA; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, IL 61801, USA; Center for East Asian and Pacific Studies, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
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Liu J, Zhu J, Xu Q, Shi R, Liu C, Sun D, Liu W. Functional identification of two novel carbohydrate-binding modules of glucuronoxylanase CrXyl30 and their contribution to the lignocellulose saccharification. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:40. [PMID: 36890582 PMCID: PMC9996879 DOI: 10.1186/s13068-023-02290-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 02/28/2023] [Indexed: 03/10/2023]
Abstract
BACKGROUND Glycoside hydrolase (GH) family 30 xylanases are a distinct group of xylanases, most of which have a highly specific catalytic activity for glucuronoxylan. Since GH30 xylanases do not normally carry carbohydrate-binding modules (CBMs), our knowledge of the function of their CBMs is lacking. RESULTS In this work, the CBM functions of CrXyl30 were investigated. CrXyl30 was a GH30 glucuronoxylanase containing tandem CBM13 (CrCBM13) and CBM2 (CrCBM2) at its C terminus, which was identified in a lignocellulolytic bacterial consortium previously. Both CBMs could bind insoluble and soluble xylan, with CrCBM13 having binding specificity for the xylan with L-arabinosyl substitutions, whereas CrCBM2 targeted L-arabinosyl side chains themselves. Such binding abilities of these two CBMs were completely different from other CBMs in their respective families. Phylogenetic analysis also suggested that both CrCBM13 and CrCBM2 belong to novel branches. Inspection of the simulated structure of CrCBM13 identified a pocket that just accommodates the side chain of 3(2)-alpha-L-arabinofuranosyl-xylotriose, which forms hydrogen bonds with three of the five amino acid residues involved in ligand interaction. The truncation of either CrCBM13 or CrCBM2 did not alter the substrate specificity and optimal reaction conditions of CrXyl30, whereas truncation of CrCBM2 decreased the kcat/Km value by 83% (± 0%). Moreover, the absence of CrCBM2 and CrCBM13 resulted in a 5% (± 1%) and a 7% (± 0%) decrease, respectively, in the amount of reducing sugar released by the synergistic hydrolysis of delignified corncob whose hemicellulose is arabinoglucuronoxylan, respectively. In addition, fusion of CrCBM2 with a GH10 xylanase enhanced its catalytic activity against the branched xylan and improved the synergistic hydrolysis efficiency by more than fivefold when delignified corncob was used as substrate. Such a strong stimulation of hydrolysis resulted from the enhancement of hemicellulose hydrolysis on the one hand, and the cellulose hydrolysis is also improved according to the lignocellulose conversion rate measured by HPLC. CONCLUSIONS This study identifies the functions of two novel CBMs in CrXyl30 and shows the good potential of such CBMs specific for branched ligands in the development of efficient enzyme preparations.
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Affiliation(s)
- Jiawen Liu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Jingrong Zhu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Qian Xu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Rui Shi
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Cong Liu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China.
| | - Di Sun
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China.
| | - Weijie Liu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No.101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China.
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9
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Laemthong T, Bing RG, Crosby JR, Manesh MJH, Adams MWW, Kelly RM. Role of cell-substrate association during plant biomass solubilization by the extreme thermophile Caldicellulosiruptor bescii. Extremophiles 2023; 27:6. [PMID: 36802247 PMCID: PMC10514702 DOI: 10.1007/s00792-023-01290-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/02/2023] [Indexed: 02/23/2023]
Abstract
Caldicellulosiruptor species are proficient at solubilizing carbohydrates in lignocellulosic biomass through surface (S)-layer bound and secretomic glycoside hydrolases. Tāpirins, surface-associated, non-catalytic binding proteins in Caldicellulosiruptor species, bind tightly to microcrystalline cellulose, and likely play a key role in natural environments for scavenging scarce carbohydrates in hot springs. However, the question arises: If tāpirin concentration on Caldicellulosiruptor cell walls increased above native levels, would this offer any benefit to lignocellulose carbohydrate hydrolysis and, hence, biomass solubilization? This question was addressed by engineering the genes for tight-binding, non-native tāpirins into C. bescii. The engineered C. bescii strains bound more tightly to microcrystalline cellulose (Avicel) and biomass compared to the parent. However, tāpirin overexpression did not significantly improve solubilization or conversion for wheat straw or sugarcane bagasse. When incubated with poplar, the tāpirin-engineered strains increased solubilization by 10% compared to the parent, and corresponding acetate production, a measure of carbohydrate fermentation intensity, was 28% higher for the Calkr_0826 expression strain and 18.5% higher for the Calhy_0908 expression strain. These results show that enhanced binding to the substrate, beyond the native capability, did not improve C. bescii solubilization of plant biomass, but in some cases may improve conversion of released lignocellulose carbohydrates to fermentation products.
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Affiliation(s)
- Tunyaboon Laemthong
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
- Department of Chemical Engineering, Thammasat University, Pathum Thani, 12120, Thailand
| | - Ryan G Bing
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - James R Crosby
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Mohamad J H Manesh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Robert M Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA.
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10
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Metatranscriptome Profiling of a Specialized Microbial Consortium during the Degradation of Nixtamalized Maize Pericarp. Microbiol Spectr 2022; 10:e0231821. [PMID: 34985337 PMCID: PMC8729791 DOI: 10.1128/spectrum.02318-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lignocellulose degradation by microbial consortia is multifactorial; hence, it must be analyzed from a holistic perspective. In this study, the temporal transcriptional activity of consortium PM-06, a nixtamalized maize pericarp (NMP) degrader, was determined and related to structural and physicochemical data to give insights into the mechanism used to degrade this substrate. Transcripts were described in terms of metabolic profile, carbohydrate-active enzyme (CAZyme) annotation, and taxonomic affiliation. The PM-06 gene expression pattern was closely related to the differential rates of degradation. The environmental and physiological conditions preceding high-degradation periods were crucial for CAZyme expression. The onset of degradation preceded the period with the highest degradation rate in the whole process, and in this time, several CAZymes were upregulated. Functional analysis of expressed CAZymes indicated that PM-06 overcomes NMP recalcitrance through modular enzymes operating at the proximity of the insoluble substrate. Increments in the diversity of expressed modular CAZymes occurred in the last stages of degradation where the substrate is more recalcitrant and environmental conditions are stressing. Taxonomic affiliation of CAZyme transcripts indicated that Paenibacillus macerans was fundamental for degradation. This microorganism established synergistic relationships with Bacillus thuringiensis for the degradation of cellulose and hemicellulose and with Microbacterium, Leifsonia, and Nocardia for the saccharification of oligosaccharides. IMPORTANCE Nixtamalized maize pericarp is an abundant residue of the tortilla industry. Consortium PM-06 efficiently degraded this substrate in 192 h. In this work, the temporal transcriptional profile of PM-06 was determined. Findings indicated that differential degradation rates are important sample selection criteria since they were closely related to the expression of carbohydrate-active enzymes (CAZymes). The initial times of degradation were crucial for the consumption of nixtamalized pericarp. A transcriptional profile at the onset of degradation is reported for the first time. Diverse CAZyme genes were rapidly transcribed after inoculation to produce different enzymes that participated in the stage with the highest degradation rate in the whole process. This study provides information about the regulation of gene expression and mechanisms used by PM-06 to overcome recalcitrance. These findings are useful in the design of processes and enzyme cocktails for the degradation of this abundant substrate.
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11
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Hu Y, Li H, Ran Q, Liu J, Zhou S, Qiao Q, Song H, Peng F, Jiang Z. Effect of carbohydrate binding modules alterations on catalytic activity of glycoside hydrolase family 6 exoglucanase from Chaetomium thermophilum to cellulose. Int J Biol Macromol 2021; 191:222-229. [PMID: 34508724 DOI: 10.1016/j.ijbiomac.2021.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 12/31/2022]
Abstract
Exoglucanase (CBH) is the rate limiting enzyme in the process of cellulose degradation. The carbohydrate binding module (CBM) can improve the accessibility of cellulase to substrate, thereby promoting the enzymatic hydrolysis of cellulase. In this study, the influence of CBM on the properties of GH6 exoglucanase from Chaetomium thermophilum (CtCBH) is systematically explored from three perspectives: the fusion of exogenous CBM, the exogenous CBM replacement of its own CBM, and the deletion of its own CBM. The parental and reconstructed CtCBH presented the same optimum pH (6.0) and temperature (60 °C) for maximum activity. Fusion of exogenous CBM increased the binding capacity of CtCBH to Avicel by 8% and 9%, respectively, but it had no significant effect on its catalytic activity. The exogenous CBM replacement of its own CBM resulted in a 12% reduction in the binding ability of CtCBH to Avicel, and a 26% reduction in the catalytic activity of Avicel. The deletion of its own CBM significantly reduced the binding ability of CtCBH to Avicel by approximately 53%, but its catalytic activity was not obviously reduced. These observations suggest that binding ability of CBM is not necessary for the catalysis of CtCBH.
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Affiliation(s)
- Yanmei Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China
| | - Huanan Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China
| | - Qiuping Ran
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China
| | - Jiashu Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China
| | - Shanna Zhou
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China
| | - Qiming Qiao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China
| | - Huiting Song
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, PR China
| | - Fang Peng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, PR China
| | - Zhengbing Jiang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei University, Wuhan 430062, PR China; Hubei Key Laboratory of Industrial Biotechnology, School of Life Science, Hubei University, Wuhan 430062, PR China.
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12
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Harvey DJ. ANALYSIS OF CARBOHYDRATES AND GLYCOCONJUGATES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY: AN UPDATE FOR 2015-2016. MASS SPECTROMETRY REVIEWS 2021; 40:408-565. [PMID: 33725404 DOI: 10.1002/mas.21651] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/24/2020] [Indexed: 06/12/2023]
Abstract
This review is the ninth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2016. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented over 30 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show no sign of deminishing. © 2020 Wiley Periodicals, Inc.
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Affiliation(s)
- David J Harvey
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
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13
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Ing N, Deng K, Chen Y, Aulitto M, Gin JW, Pham TLM, Petzold CJ, Singer SW, Bowen B, Sale KL, Simmons BA, Singh AK, Adams PD, Northen TR. A multiplexed nanostructure-initiator mass spectrometry (NIMS) assay for simultaneously detecting glycosyl hydrolase and lignin modifying enzyme activities. Sci Rep 2021; 11:11803. [PMID: 34083602 PMCID: PMC8175421 DOI: 10.1038/s41598-021-91181-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/07/2021] [Indexed: 11/09/2022] Open
Abstract
Lignocellulosic biomass is composed of three major biopolymers: cellulose, hemicellulose and lignin. Analytical tools capable of quickly detecting both glycan and lignin deconstruction are needed to support the development and characterization of efficient enzymes/enzyme cocktails. Previously we have described nanostructure-initiator mass spectrometry-based assays for the analysis of glycosyl hydrolase and most recently an assay for lignin modifying enzymes. Here we integrate these two assays into a single multiplexed assay against both classes of enzymes and use it to characterize crude commercial enzyme mixtures. Application of our multiplexed platform based on nanostructure-initiator mass spectrometry enabled us to characterize crude mixtures of laccase enzymes from fungi Agaricus bisporus (Ab) and Myceliopthora thermophila (Mt) revealing activity on both carbohydrate and aromatic substrates. Using time-series analysis we determined that crude laccase from Ab has the higher GH activity and that laccase from Mt has the higher activity against our lignin model compound. Inhibitor studies showed a significant reduction in Mt GH activity under low oxygen conditions and increased activities in the presence of vanillin (common GH inhibitor). Ultimately, this assay can help to discover mixtures of enzymes that could be incorporated into biomass pretreatments to deconstruct diverse components of lignocellulosic biomass.
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Affiliation(s)
- Nicole Ing
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Sandia National Laboratories, Livermore, CA, 94551, USA
| | - Kai Deng
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Sandia National Laboratories, Livermore, CA, 94551, USA
| | - Yan Chen
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Martina Aulitto
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jennifer W Gin
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Thanh Le Mai Pham
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Sandia National Laboratories, Livermore, CA, 94551, USA
| | - Christopher J Petzold
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Steve W Singer
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Benjamin Bowen
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kenneth L Sale
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Sandia National Laboratories, Livermore, CA, 94551, USA
| | - Blake A Simmons
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Anup K Singh
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Sandia National Laboratories, Livermore, CA, 94551, USA
| | - Paul D Adams
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA.,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,University of California, Berkeley, CA, 94720, USA
| | - Trent R Northen
- Joint BioEnergy Institute, Emeryville, CA, 94608, USA. .,Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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14
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Rajnish KN, Samuel MS, John J A, Datta S, Chandrasekar N, Balaji R, Jose S, Selvarajan E. Immobilization of cellulase enzymes on nano and micro-materials for breakdown of cellulose for biofuel production-a narrative review. Int J Biol Macromol 2021; 182:1793-1802. [PMID: 34058212 DOI: 10.1016/j.ijbiomac.2021.05.176] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/02/2021] [Accepted: 05/26/2021] [Indexed: 12/18/2022]
Abstract
Cellulose is a very abundant polymer that is found in nature. Cellulose has been used as a raw material for production of biofuels for many years. However, there are multiple processing steps that are required so that cellulose can be used as a raw material for biofuel production. One of the most important steps is the breakdown of cellulose into intermediate sugars which can then be a viable substrate for biofuel production. Cellulases are enzymes which play a role in the catalysis of the breakdown of cellulose into glucose. Nanomaterials and micromaterials have been gaining a lot of attention over the past few years for its potential in immobilizing enzymes for industrial procedures. Immobilization of enzymes on these nanomaterials has been observed to be of great value due to the improvement in thermal stability, pH stability, regenerative capacity, increase in activity and the reusability of enzymes. Similarly, there have been multiple reports of cellulase enzymes being immobilized on various nanoparticles. The immobilization of these cellulase enzymes have resulted in very efficient processing and provide a great and economic solution for the processing of cellulose for biofuel production. Hence in this paper, we review and discuss the various advantages and disadvantages of enzymes on various available nanomaterials.
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Affiliation(s)
- K Narayanan Rajnish
- Department of Genetic Engineering, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India
| | - Melvin S Samuel
- School of Environmental Science and Engineering, School of Bioengineering, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Ashwini John J
- Department of Genetic Engineering, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India
| | - Saptashwa Datta
- Department of Genetic Engineering, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India
| | - Narendhar Chandrasekar
- Department of Nanoscience and Technology, Sri Ramakrishna Engineering College, Coimbatore, India
| | - Ramachandran Balaji
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taiwan
| | - Sujin Jose
- School of Physics, Madurai Kamaraj University, Madurai, Tamil Nadu 625021, India
| | - Ethiraj Selvarajan
- Department of Genetic Engineering, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India.
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15
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Liu J, Sun D, Zhu J, Liu C, Liu W. Carbohydrate-binding modules targeting branched polysaccharides: overcoming side-chain recalcitrance in a non-catalytic approach. BIORESOUR BIOPROCESS 2021; 8:28. [PMID: 38650221 PMCID: PMC10992016 DOI: 10.1186/s40643-021-00381-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 04/07/2021] [Indexed: 12/25/2022] Open
Abstract
Extensive decoration of backbones is a major factor resulting in resistance of enzymatic conversion in hemicellulose and other branched polysaccharides. Employing debranching enzymes is the main strategy to overcome this kind of recalcitrance at present. A carbohydrate-binding module (CBM) is a contiguous amino acid sequence that can promote the binding of enzymes to various carbohydrates, thereby facilitating enzymatic hydrolysis. According to previous studies, CBMs can be classified into four types based on their preference in ligand type, where Type III and IV CBMs prefer to branched polysaccharides than the linear and thus are able to specifically enhance the hydrolysis of substrates containing side chains. With a role in dominating the hydrolysis of branched substrates, Type III and IV CBMs could represent a non-catalytic approach in overcoming side-chain recalcitrance.
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Affiliation(s)
- Jiawen Liu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No. 101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Di Sun
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No. 101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Jingrong Zhu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No. 101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China
| | - Cong Liu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No. 101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China.
| | - Weijie Liu
- Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, No. 101, Shanghai Road, Tongshan New District, Xuzhou, 221116, Jiangsu, China.
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16
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Chundawat SPS, Nemmaru B, Hackl M, Brady SK, Hilton MA, Johnson MM, Chang S, Lang MJ, Huh H, Lee SH, Yarbrough JM, López CA, Gnanakaran S. Molecular origins of reduced activity and binding commitment of processive cellulases and associated carbohydrate-binding proteins to cellulose III. J Biol Chem 2021; 296:100431. [PMID: 33610545 PMCID: PMC8010709 DOI: 10.1016/j.jbc.2021.100431] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 02/11/2021] [Accepted: 02/16/2021] [Indexed: 11/30/2022] Open
Abstract
Efficient enzymatic saccharification of cellulosic biomass into fermentable sugars can enable production of bioproducts like ethanol. Native crystalline cellulose, or cellulose I, is inefficiently processed via enzymatic hydrolysis but can be converted into the structurally distinct cellulose III allomorph that is processed via cellulase cocktails derived from Trichoderma reesei up to 20-fold faster. However, characterization of individual cellulases from T. reesei, like the processive exocellulase Cel7A, shows reduced binding and activity at low enzyme loadings toward cellulose III. To clarify this discrepancy, we monitored the single-molecule initial binding commitment and subsequent processive motility of Cel7A enzymes and associated carbohydrate-binding modules (CBMs) on cellulose using optical tweezers force spectroscopy. We confirmed a 48% lower initial binding commitment and 32% slower processive motility of Cel7A on cellulose III, which we hypothesized derives from reduced binding affinity of the Cel7A binding domain CBM1. Classical CBM–cellulose pull-down assays, depending on the adsorption model fitted, predicted between 1.2- and 7-fold reduction in CBM1 binding affinity for cellulose III. Force spectroscopy measurements of CBM1–cellulose interactions, along with molecular dynamics simulations, indicated that previous interpretations of classical binding assay results using multisite adsorption models may have complicated analysis, and instead suggest simpler single-site models should be used. These findings were corroborated by binding analysis of other type-A CBMs (CBM2a, CBM3a, CBM5, CBM10, and CBM64) on both cellulose allomorphs. Finally, we discuss how complementary analytical tools are critical to gain insight into the complex mechanisms of insoluble polysaccharides hydrolysis by cellulolytic enzymes and associated carbohydrate-binding proteins.
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Affiliation(s)
- Shishir P S Chundawat
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA.
| | - Bhargava Nemmaru
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Markus Hackl
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Sonia K Brady
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Mark A Hilton
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Madeline M Johnson
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Sungrok Chang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Hyun Huh
- Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Sang-Hyuk Lee
- Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - John M Yarbrough
- Biosciences Center, National Renewable Energy Lab, Golden, Colorado, USA
| | - Cesar A López
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
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17
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Glasgow E, Vander Meulen K, Kuch N, Fox BG. Multifunctional cellulases are potent, versatile tools for a renewable bioeconomy. Curr Opin Biotechnol 2021; 67:141-148. [PMID: 33550093 PMCID: PMC8366578 DOI: 10.1016/j.copbio.2020.12.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/09/2020] [Accepted: 12/28/2020] [Indexed: 11/21/2022]
Abstract
Enzyme performance is critical to the future bioeconomy based on renewable plant materials. Plant biomass can be efficiently hydrolyzed by multifunctional cellulases (MFCs) into sugars suitable for conversion into fuels and chemicals, and MFCs fall into three functional categories. Recent work revealed MFCs with broad substrate specificity, dual exo-activity/endo-activity on cellulose, and intramolecular synergy, among other novel characteristics. Binding modules and accessory catalytic domains amplify MFC and xylanase activity in a wide variety of ways, and processive endoglucanases achieve autosynergy on cellulose. Multidomain MFCs from Caldicellulosiruptor are heat-tolerant, adaptable to variable cellulose crystallinity, and may provide interchangeable scaffolds for recombinant design. Further studies of MFC properties and their reactivity with plant biomass are recommended for increasing biorefinery yields.
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Affiliation(s)
- Evan Glasgow
- Dept. of Biochemistry, University of Wisconsin - Madison, 433 Babcock Dr., Madison, WI, 53706, United States; Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, 1552 University Ave, Madison, WI, 53726, United States
| | - Kirk Vander Meulen
- Dept. of Biochemistry, University of Wisconsin - Madison, 433 Babcock Dr., Madison, WI, 53706, United States; Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, 1552 University Ave, Madison, WI, 53726, United States
| | - Nate Kuch
- Dept. of Biochemistry, University of Wisconsin - Madison, 433 Babcock Dr., Madison, WI, 53706, United States; Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, 1552 University Ave, Madison, WI, 53726, United States
| | - Brian G Fox
- Dept. of Biochemistry, University of Wisconsin - Madison, 433 Babcock Dr., Madison, WI, 53706, United States; Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, 1552 University Ave, Madison, WI, 53726, United States.
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18
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Pinheiro MP, Reis RA, Dupree P, Ward RJ. Plant cell wall architecture guided design of CBM3-GH11 chimeras with enhanced xylanase activity using a tandem repeat left-handed β-3-prism scaffold. Comput Struct Biotechnol J 2021; 19:1108-1118. [PMID: 33680354 PMCID: PMC7890094 DOI: 10.1016/j.csbj.2021.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 01/19/2023] Open
Abstract
Effective use of plant biomass as an abundant and renewable feedstock for biofuel production and biorefinery requires efficient enzymatic mobilization of cell wall polymers. Knowledge of plant cell wall composition and architecture has been exploited to develop novel multifunctional enzymes with improved activity against lignocellulose, where a left-handed β-3-prism synthetic scaffold (BeSS) was designed for insertion of multiple protein domains at the prism vertices. This allowed construction of a series of chimeras fusing variable numbers of a GH11 β-endo-1,4-xylanase and the CipA-CBM3 with defined distances and constrained relative orientations between catalytic domains. The cellulose binding and endoxylanase activities of all chimeras were maintained. Activity against lignocellulose substrates revealed a rapid 1.6- to 3-fold increase in total reducing saccharide release and increased levels of all major oligosaccharides as measured by polysaccharide analysis using carbohydrate gel electrophoresis (PACE). A construct with CBM3 and GH11 domains inserted in the same prism vertex showed highest activity, demonstrating interdomain geometry rather than number of catalytic sites is important for optimized chimera design. These results confirm that the BeSS concept is robust and can be successfully applied to the construction of multifunctional chimeras, which expands the possibilities for knowledge-based protein design.
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Affiliation(s)
- Matheus P. Pinheiro
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14040-901, Brazil
| | - Renata A.G. Reis
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Ribeirão Preto, SP CEP 14040-901, Brazil
| | - Paul Dupree
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Richard J. Ward
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14040-901, Brazil
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19
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Ogonda LA, Saumonneau A, Dion M, Muge EK, Wamalwa BM, Mulaa FJ, Tellier C. Characterization and engineering of two new GH9 and GH48 cellulases from a Bacillus pumilus isolated from Lake Bogoria. Biotechnol Lett 2021; 43:691-700. [PMID: 33386499 DOI: 10.1007/s10529-020-03056-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/10/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To search for new alkaliphilic cellulases and to improve their efficiency on crystalline cellulose through molecular engineering RESULTS: Two novel cellulases, BpGH9 and BpGH48, from a Bacillus pumilus strain were identified, cloned and biochemically characterized. BpGH9 is a modular endocellulase belonging to the glycoside hydrolase 9 family (GH9), which contains a catalytic module (GH) and a carbohydrate-binding module belonging to class 3 and subclass c (CBM3c). This enzyme is extremely tolerant to high alkali pH and remains significantly active at pH 10. BpGH48 is an exocellulase, belonging to the glycoside hydrolase 48 family (GH48) and acts on the reducing end of oligo-β1,4 glucanes. A truncated form of BpGH9 and a chimeric fusion with an additional CBM3a module was constructed. The deletion of the CBM3c module results in a significant decline in the catalytic activity. However, fusion of CBM3a, although in a non native position, enhanced the activity of BpGH9 on crystalline cellulose. CONCLUSIONS A new alkaliphilic endocellulase BpGH9, was cloned and engineered as a fusion protein (CBM3a-BpGH9), which led to an improved activity on crystalline cellulose.
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Affiliation(s)
- Lydia A Ogonda
- Université de Nantes, CNRS, UFIP, UMR6286, 2, rue de la Houssinière, 44322, Nantes, France.,Department of Biochemistry, School of Medicine, College of Health Sciences, University of Nairobi, P.O BOX 30197-00100, Nairobi, Kenya.,Department of Medical Biochemistry, School of Medicine, Masinde Muliro University of Science and Technology, P.O BOX 190-50100, Kakamega, Kenya
| | - Amélie Saumonneau
- Université de Nantes, CNRS, UFIP, UMR6286, 2, rue de la Houssinière, 44322, Nantes, France
| | - Michel Dion
- Université de Nantes, IRS2, 44000, Nantes, France
| | - Edward K Muge
- Department of Biochemistry, School of Medicine, College of Health Sciences, University of Nairobi, P.O BOX 30197-00100, Nairobi, Kenya
| | - Benson M Wamalwa
- Department of Chemistry, School of Physical Sciences, College of Biological and Physical Sciences, University of Nairobi, P.O BOX 30197-00100, Nairobi, Kenya
| | - Francis J Mulaa
- Department of Biochemistry, School of Medicine, College of Health Sciences, University of Nairobi, P.O BOX 30197-00100, Nairobi, Kenya
| | - Charles Tellier
- Université de Nantes, CNRS, UFIP, UMR6286, 2, rue de la Houssinière, 44322, Nantes, France.
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Nemmaru B, Ramirez N, Farino CJ, Yarbrough JM, Kravchenko N, Chundawat SPS. Reduced type-A carbohydrate-binding module interactions to cellulose I leads to improved endocellulase activity. Biotechnol Bioeng 2020; 118:1141-1151. [PMID: 33245142 DOI: 10.1002/bit.27637] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/12/2020] [Accepted: 11/15/2020] [Indexed: 12/24/2022]
Abstract
Dissociation of nonproductively bound cellulolytic enzymes from cellulose is hypothesized to be a key rate-limiting factor impeding cost-effective biomass conversion to fermentable sugars. However, the role of carbohydrate-binding modules (CBMs) in enabling nonproductive enzyme binding is not well understood. Here, we examine the subtle interplay of CBM binding and cellulose hydrolysis activity for three models type-A CBMs (Families 1, 3a, and 64) tethered to multifunctional endoglucanase (CelE) on two distinct cellulose allomorphs (i.e., cellulose I and III). We generated a small library of mutant CBMs with varying cellulose affinity, as determined by equilibrium binding assays, followed by monitoring cellulose hydrolysis activity of CelE-CBM fusion constructs. Finally, kinetic binding assays using quartz crystal microbalance with dissipation were employed to measure CBM adsorption and desorption rate constants k on and k off , respectively, towards nanocrystalline cellulose derived from both allomorphs. Overall, our results indicate that reduced CBM equilibrium binding affinity towards cellulose I alone, resulting from increased desorption rates ( k off ) and reduced effective adsorption rates ( nk on ), is correlated to overall improved endocellulase activity. Future studies could employ similar approaches to unravel the role of CBMs in nonproductive enzyme binding and develop improved cellulolytic enzymes for industrial applications.
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Affiliation(s)
| | - Nicholas Ramirez
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Cindy J Farino
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - John M Yarbrough
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
| | - Nicholas Kravchenko
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Shishir P S Chundawat
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
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Bandi CK, Goncalves A, Pingali SV, Chundawat SPS. Carbohydrate‐binding domains facilitate efficient oligosaccharides synthesis by enhancing mutant catalytic domain transglycosylation activity. Biotechnol Bioeng 2020; 117:2944-2956. [DOI: 10.1002/bit.27473] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/16/2020] [Accepted: 06/21/2020] [Indexed: 01/31/2023]
Affiliation(s)
- Chandra Kanth Bandi
- Department of Chemical and Biochemical Engineering, Rutgers The State University of New Jersey Piscataway New Jersey
| | - Antonio Goncalves
- Department of Chemical and Biochemical Engineering, Rutgers The State University of New Jersey Piscataway New Jersey
| | - Sai Venkatesh Pingali
- Neutron Scattering Division, Center for Structural Molecular Biology Oak Ridge National Laboratory Oak Ridge Tennessee
| | - Shishir P. S. Chundawat
- Department of Chemical and Biochemical Engineering, Rutgers The State University of New Jersey Piscataway New Jersey
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Structural and Functional Studies of a Klebsiella Phage Capsule Depolymerase Tailspike: Mechanistic Insights into Capsular Degradation. Structure 2020; 28:613-624.e4. [PMID: 32386574 DOI: 10.1016/j.str.2020.04.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/09/2020] [Accepted: 04/17/2020] [Indexed: 01/01/2023]
Abstract
Capsule polysaccharide is a major virulence factor of Klebsiella pneumoniae, a nosocomial pathogen associated with a wide range of infections. It protects bacteria from harsh environmental conditions, immune system response, and phage infection. To access cell wall-located receptors, some phages possess tailspike depolymerases that degrade the capsular polysaccharide. Here, we present the crystal structure of a tailspike against Klebsiella, KP32gp38, whose primary sequence shares no similarity to other proteins of known structure. In the trimeric structure of KP32gp38, each chain contains a flexible N-terminal domain, a right-handed parallel β helix domain and two β sandwiches with carbohydrate binding features. The crystal structure and activity assays allowed us to locate the catalytic site. Also, our data provide experimental evidence of a branching architecture of depolymerases in KP32 Klebsiella viruses, as KP32gp38 displays nanomolar affinity to another depolymerase from the same phage, KP32gp37. Results provide a structural framework for enzyme engineering to produce serotype-broad-active enzyme complexes against K. pneumoniae.
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23
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Consolidated bio-saccharification: Leading lignocellulose bioconversion into the real world. Biotechnol Adv 2020; 40:107535. [DOI: 10.1016/j.biotechadv.2020.107535] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/03/2020] [Accepted: 02/12/2020] [Indexed: 11/22/2022]
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24
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Ribeiro LF, Amarelle V, Alves LDF, Viana de Siqueira GM, Lovate GL, Borelli TC, Guazzaroni ME. Genetically Engineered Proteins to Improve Biomass Conversion: New Advances and Challenges for Tailoring Biocatalysts. Molecules 2019; 24:molecules24162879. [PMID: 31398877 PMCID: PMC6719137 DOI: 10.3390/molecules24162879] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 07/30/2019] [Accepted: 08/06/2019] [Indexed: 01/02/2023] Open
Abstract
Protein engineering emerged as a powerful approach to generate more robust and efficient biocatalysts for bio-based economy applications, an alternative to ecologically toxic chemistries that rely on petroleum. On the quest for environmentally friendly technologies, sustainable and low-cost resources such as lignocellulosic plant-derived biomass are being used for the production of biofuels and fine chemicals. Since most of the enzymes used in the biorefinery industry act in suboptimal conditions, modification of their catalytic properties through protein rational design and in vitro evolution techniques allows the improvement of enzymatic parameters such as specificity, activity, efficiency, secretability, and stability, leading to better yields in the production lines. This review focuses on the current application of protein engineering techniques for improving the catalytic performance of enzymes used to break down lignocellulosic polymers. We discuss the use of both classical and modern methods reported in the literature in the last five years that allowed the boosting of biocatalysts for biomass degradation.
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Affiliation(s)
- Lucas Ferreira Ribeiro
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil.
| | - Vanesa Amarelle
- Department of Microbial Biochemistry and Genomics, Biological Research Institute Clemente Estable, Montevideo, PC 11600, Uruguay
| | - Luana de Fátima Alves
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | | | - Gabriel Lencioni Lovate
- Department of Biochemistry and Immunology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Tiago Cabral Borelli
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
| | - María-Eugenia Guazzaroni
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil.
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25
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Vita N, Borne R, Perret S, de Philip P, Fierobe HP. Turning a potent family-9 free cellulase into an operational cellulosomal component and vice versa. FEBS J 2019; 286:3359-3373. [PMID: 31004451 DOI: 10.1111/febs.14858] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/18/2019] [Accepted: 04/16/2019] [Indexed: 11/29/2022]
Abstract
Ruminiclostridium cellulolyticum and Lachnoclostridium phytofermentans are cellulolytic clostridia either producing extracellular multienzymatic complexes termed cellulosomes or secreting free cellulases respectively. In the free state, the cellulase Cel9A secreted by L. phytofermentans is much more active on crystalline cellulose than any cellulosomal family-9 enzyme produced by R. cellulolyticum. Nevertheless, the incorporation of Cel9A in vitro in hybrid cellulosomes was formerly shown to generate artificial complexes with altered activity, whereas its incorporation in vivo in native R. cellulolyticum cellulosomes resulted in a strain displaying a weakened cellulolytic phenotype. In this study, we investigated why Cel9A is so potent in the free state but functions poorly as a cellulosomal component, in contrast to the most similar enzyme synthesized by R. cellulolyticum, Cel9G, weakly active in the free state but whose activity on crystalline cellulose is drastically increased in cellulosomes. We show that the removal of the C-terminal moiety of Cel9A encompassing the two X2 modules and the family-3b carbohydrate binding module (CBM3b), reduces its activity on crystalline cellulose. Grafting a dockerin module further diminishes the activity, but this truncated cellulosomal form of Cel9A displays important synergies in hybrid cellulosomes with the pivotal family-48 cellulosomal enzyme of R. cellulolyticum. The exact inverse approach was applied to the cellulosomal Cel9G. Grafting the two X2 modules and the CBM3b of Cel9A to Cel9G strongly increases its activity on crystalline cellulose, to reach Cel9A activity levels. Altogether these data emphasize the specific features required to generate an efficient free or cellulosomal family-9 cellulase.
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Guo X, Yang F, Liu H, Hou Y, Wang Y, Sun J, Chen X, Liu Y, Li X. Prediction of Cellulose Crystallinity in Liquid Phase Using CBM-GFP Probe. Macromol Res 2019. [DOI: 10.1007/s13233-019-7059-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Glasgow EM, Vander Meulen KA, Takasuka TE, Bianchetti CM, Bergeman LF, Deutsch S, Fox BG. Extent and Origins of Functional Diversity in a Subfamily of Glycoside Hydrolases. J Mol Biol 2019; 431:1217-1233. [PMID: 30685401 DOI: 10.1016/j.jmb.2019.01.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/19/2018] [Accepted: 01/16/2019] [Indexed: 12/16/2022]
Abstract
Some glycoside hydrolases have broad specificity for hydrolysis of glycosidic bonds, potentially increasing their functional utility and flexibility in physiological and industrial applications. To deepen the understanding of the structural and evolutionary driving forces underlying specificity patterns in glycoside hydrolase family 5, we quantitatively screened the activity of the catalytic core domains from subfamily 4 (GH5_4) and closely related enzymes on four substrates: lichenan, xylan, mannan, and xyloglucan. Phylogenetic analysis revealed that GH5_4 consists of three major clades, and one of these clades, referred to here as clade 3, displayed average specific activities of 4.2 and 1.2 U/mg on lichenan and xylan, approximately 1 order of magnitude larger than the average for active enzymes in clades 1 and 2. Enzymes in clade 3 also more consistently met assay detection thresholds for reaction with all four substrates. We also identified a subfamily-wide positive correlation between lichenase and xylanase activities, as well as a weaker relationship between lichenase and xyloglucanase. To connect these results to structural features, we used the structure of CelE from Hungateiclostridium thermocellum (PDB 4IM4) as an example clade 3 enzyme with activities on all four substrates. Comparison of the sequence and structure of this enzyme with others throughout GH5_4 and neighboring subfamilies reveals at least two residues (H149 and W203) that are linked to strong activity across the substrates. Placing GH5_4 in context with other related subfamilies, we highlight several possibilities for the ongoing evolutionary specialization of GH5_4 enzymes.
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Affiliation(s)
- Evan M Glasgow
- Great Lakes Bioenergy Research Center, Madison, WI 53706 USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706 USA
| | - Kirk A Vander Meulen
- Great Lakes Bioenergy Research Center, Madison, WI 53706 USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706 USA
| | - Taichi E Takasuka
- Great Lakes Bioenergy Research Center, Madison, WI 53706 USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706 USA; Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan
| | - Christopher M Bianchetti
- Great Lakes Bioenergy Research Center, Madison, WI 53706 USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706 USA; Department of Chemistry, University of Wisconsin, Oshkosh, 54901 USA
| | - Lai F Bergeman
- Great Lakes Bioenergy Research Center, Madison, WI 53706 USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706 USA
| | | | - Brian G Fox
- Great Lakes Bioenergy Research Center, Madison, WI 53706 USA; Department of Biochemistry, University of Wisconsin, Madison, WI 53706 USA.
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Maharjan A, Alkotaini B, Kim BS. Fusion of Carbohydrate Binding Modules to Bifunctional Cellulase to Enhance Binding Affinity and Cellulolytic Activity. BIOTECHNOL BIOPROC E 2018. [DOI: 10.1007/s12257-018-0011-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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29
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Enhanced features of Dictyoglomus turgidum Cellulase A engineered with carbohydrate binding module 11 from Clostridium thermocellum. Sci Rep 2018. [PMID: 29535356 PMCID: PMC5849603 DOI: 10.1038/s41598-018-22769-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Lignocellulosic biomass (LCB) is a low-cost and abundant source of fermentable sugars. Enzymatic hydrolysis is one of the main ways to obtain sugars from biomass, but most of the polysaccharide-degrading enzymes are poorly efficient on LCB and cellulases with higher performances are required. In this study, we designed a chimeric protein by adding the carbohydrate binding module (CBM) of the cellulosomal enzyme CtLic26A-Cel5E (endoglucanase H or CelH) from Clostridium (Ruminiclostridium) thermocellum to the C-terminus of Dtur CelA, an interesting hyperthermostable endoglucanase from Dictyoglomus turgidum. The activity and binding rate of both native and chimeric enzyme were evaluated on soluble and insoluble polysaccharides. The addition of a CBM resulted in a cellulase with enhanced stability at extreme pHs, higher affinity and activity on insoluble cellulose.
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Carbohydrate active enzyme domains from extreme thermophiles: components of a modular toolbox for lignocellulose degradation. Extremophiles 2017; 22:1-12. [PMID: 29110088 DOI: 10.1007/s00792-017-0974-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/24/2017] [Indexed: 02/06/2023]
Abstract
Lignocellulosic biomass is a promising feedstock for the manufacture of biodegradable and renewable bioproducts. However, the complex lignocellulosic polymeric structure of woody tissue is difficult to access without extensive industrial pre-treatment. Enzyme processing of partly depolymerised biomass is an established technology, and there is evidence that high temperature (extremely thermophilic) lignocellulose degrading enzymes [carbohydrate active enzymes (CAZymes)] may enhance processing efficiency. However, wild-type thermophilic CAZymes will not necessarily be functionally optimal under industrial pre-treatment conditions. With recent advances in synthetic biology, it is now potentially possible to build CAZyme constructs from individual protein domains, tailored to the conditions of specific industrial processes. In this review, we identify a 'toolbox' of thermostable CAZyme domains from extremely thermophilic organisms and highlight recent advances in CAZyme engineering which will allow for the rational design of CAZymes tailored to specific aspects of lignocellulose digestion.
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Setter-Lamed E, Moraïs S, Stern J, Lamed R, Bayer EA. Modular Organization of the Thermobifida fusca Exoglucanase Cel6B Impacts Cellulose Hydrolysis and Designer Cellulosome Efficiency. Biotechnol J 2017; 12. [PMID: 28901714 DOI: 10.1002/biot.201700205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/06/2017] [Indexed: 11/09/2022]
Abstract
Cellulose deconstruction can be achieved by three distinct enzymatic paradigms: free enzymes, multifunctional enzymes, and self-assembled, multi-enzyme complexes (cellulosomes). To study their comparative efficiency, the simple and efficient cellulolytic system of the aerobic bacterium, Thermobifida fusca, is developed as an enzymatic model. In previous studies, most of its cellulases are successfully converted to the cellulosomal mode and exhibited high cellulolytic activities, except for Cel6B, a key exoglucanase of the T. fusca enzymatic system. Here, the impact of the modular organization of Cel6B on enzymatic activity is investigated. The position of the cellulose-binding module (CBM), its family and linker segment are shown to affect activity. Surprisingly, exchange of the native family-2 CBM to family-3 generates an increase in Cel6B activity on cellulosic substrates. Conversion of Cel6B to the cellulosomal mode by fusing a cohesin to the catalytic module enables formation of divalent enzyme complexes with dockerin-bearing enzymes. The resultant pseudo-cellulosomes, containing Cel6B combined with endoglucanase Cel5A, exhibits enhanced enzymatic activity, compared to mixtures of wild-type enzymes or bifunctional enzymes, unlike similar pseudo-cellulosomes containing endoglucanase Cel6A or proccessive endoglucanase Cel9A. Insight into the different enzymatic paradigms benefits ongoing development of efficient cellulolytic systems for conversion of plant-derived biomass into valuable sugars. NOVELTY STATEMENT The protein engineering of the modular arrangement of a key exoglucanase from a highly cellulolytic bacterium, Thermobifida fusca, served to explore and compare three major enzymatic paradigms for cellulose degradation. This approach revealed highly active chimaeric forms of the exoglucanase that act in synergy together with a potent endoglucanase in bifunctional enzymes or divalent pseudo-cellulosome-like complexes. Such engineered enzymes could be further integrated into larger enzymatic complexes, thereby providing a significant step forward towards conversion of the entire T. fusca free cellulolytic system into the cellulosomal modex and the enhanced conversion of cellulosic biomass into soluble sugars.
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Affiliation(s)
- Eva Setter-Lamed
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Sarah Moraïs
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Johanna Stern
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Raphael Lamed
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel
| | - Edward A Bayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
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Armenta S, Moreno-Mendieta S, Sánchez-Cuapio Z, Sánchez S, Rodríguez-Sanoja R. Advances in molecular engineering of carbohydrate-binding modules. Proteins 2017; 85:1602-1617. [PMID: 28547780 DOI: 10.1002/prot.25327] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/04/2017] [Accepted: 05/20/2017] [Indexed: 11/06/2022]
Abstract
Carbohydrate-binding modules (CBMs) are non-catalytic domains that are generally appended to carbohydrate-active enzymes. CBMs have a broadly conserved structure that allows recognition of a notable variety of carbohydrates, in both their soluble and insoluble forms, as well as in their alpha and beta conformations and with different types of bonds or substitutions. This versatility suggests a high functional plasticity that is not yet clearly understood, in spite of the important number of studies relating protein structure and function. Several studies have explored the flexibility of these systems by changing or improving their specificity toward substrates of interest. In this review, we examine the molecular strategies used to identify CBMs with novel or improved characteristics. The impact of the spatial arrangement of the functional amino acids of CBMs is discussed in terms of unexpected new functions that are not related to the original biological roles of the enzymes. Proteins 2017; 85:1602-1617. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Silvia Armenta
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Mario de la Cueva s/n Ciudad Universitaria, Ciudad de México, 04510, México
| | - Silvia Moreno-Mendieta
- CONACYT, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Mario de la Cueva s/n Ciudad Universitaria, Ciudad de México, 04510, México
| | - Zaira Sánchez-Cuapio
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Mario de la Cueva s/n Ciudad Universitaria, Ciudad de México, 04510, México
| | - Sergio Sánchez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Mario de la Cueva s/n Ciudad Universitaria, Ciudad de México, 04510, México
| | - Romina Rodríguez-Sanoja
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Circuito Mario de la Cueva s/n Ciudad Universitaria, Ciudad de México, 04510, México
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Duan CJ, Huang MY, Pang H, Zhao J, Wu CX, Feng JX. Characterization of a novel theme C glycoside hydrolase family 9 cellulase and its CBM-chimeric enzymes. Appl Microbiol Biotechnol 2017; 101:5723-5737. [DOI: 10.1007/s00253-017-8320-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/09/2017] [Accepted: 04/29/2017] [Indexed: 01/27/2023]
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Hedin N, Barchiesi J, Gomez-Casati DF, Iglesias AA, Ballicora MA, Busi MV. Identification and characterization of a novel starch branching enzyme from the picoalgae Ostreococcus tauri. Arch Biochem Biophys 2017; 618:52-61. [DOI: 10.1016/j.abb.2017.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/16/2017] [Accepted: 02/18/2017] [Indexed: 01/26/2023]
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35
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Walker JA, Pattathil S, Bergeman LF, Beebe ET, Deng K, Mirzai M, Northen TR, Hahn MG, Fox BG. Determination of glycoside hydrolase specificities during hydrolysis of plant cell walls using glycome profiling. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:31. [PMID: 28184246 PMCID: PMC5288845 DOI: 10.1186/s13068-017-0703-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/06/2017] [Indexed: 05/29/2023]
Abstract
BACKGROUND Glycoside hydrolases (GHs) are enzymes that hydrolyze polysaccharides into simple sugars. To better understand the specificity of enzyme hydrolysis within the complex matrix of polysaccharides found in the plant cell wall, we studied the reactions of individual enzymes using glycome profiling, where a comprehensive collection of cell wall glycan-directed monoclonal antibodies are used to detect polysaccharide epitopes remaining in the walls after enzyme treatment and quantitative nanostructure initiator mass spectrometry (oxime-NIMS) to determine soluble sugar products of their reactions. RESULTS Single, purified enzymes from the GH5_4, GH10, and GH11 families of glycoside hydrolases hydrolyzed hemicelluloses as evidenced by the loss of specific epitopes from the glycome profiles in enzyme-treated plant biomass. The glycome profiling data were further substantiated by oxime-NIMS, which identified hexose products from hydrolysis of cellulose, and pentose-only and mixed hexose-pentose products from the hydrolysis of hemicelluloses. The GH10 enzyme proved to be reactive with the broadest diversity of xylose-backbone polysaccharide epitopes, but was incapable of reacting with glucose-backbone polysaccharides. In contrast, the GH5 and GH11 enzymes studied here showed the ability to react with both glucose- and xylose-backbone polysaccharides. CONCLUSIONS The identification of enzyme specificity for a wide diversity of polysaccharide structures provided by glycome profiling, and the correlated identification of soluble oligosaccharide hydrolysis products provided by oxime-NIMS, offers a unique combination to understand the hydrolytic capabilities and constraints of individual enzymes as they interact with plant biomass.
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Affiliation(s)
- Johnnie A. Walker
- US Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706 USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Sivakumar Pattathil
- US Department of Energy Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Lai F. Bergeman
- US Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706 USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Emily T. Beebe
- US Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706 USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Kai Deng
- US Department of Energy Joint Bioenergy Institute, Emeryville, CA 94608 USA
- Sandia National Laboratories, Livermore, CA 94551 USA
| | - Maryam Mirzai
- US Department of Energy Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Trent R. Northen
- US Department of Energy Joint Bioenergy Institute, Emeryville, CA 94608 USA
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Michael G. Hahn
- US Department of Energy Bioenergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602 USA
| | - Brian G. Fox
- US Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706 USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706 USA
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Kubicek CP, Kubicek EM. Enzymatic deconstruction of plant biomass by fungal enzymes. Curr Opin Chem Biol 2016; 35:51-57. [DOI: 10.1016/j.cbpa.2016.08.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 08/25/2016] [Accepted: 08/26/2016] [Indexed: 10/21/2022]
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Liu S, Ding S. Replacement of carbohydrate binding modules improves acetyl xylan esterase activity and its synergistic hydrolysis of different substrates with xylanase. BMC Biotechnol 2016; 16:73. [PMID: 27770795 PMCID: PMC5075172 DOI: 10.1186/s12896-016-0305-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/13/2016] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Acetylation of the xylan backbone was a major obstacle to enzymatic decomposition. Removal of acetyl groups by acetyl xylan esterases (AXEs) is essential for completely enzymatic hydrolysis of xylan. Appended carbohydrate binding modules (CBMs) can promote the enzymatic deconstruction of plant cell walls by targeting and proximity effects. Fungal acetyl xylan esterases are strictly appended to cellulose-specific CBM1. It is still unclear whether xylan-specific CBMs have a greater advantage than CBM1 in potentiating the activity of fungal deacetylating enzymes and its synergistic hydrolysis of different substrates with xylanase. RESULTS Three recombinant AXE1s fused with different xylan-specific CBMs, together with wild-type AXE1 with CBM1 and CBM1-deleted mutant AXE1dC, were constructed in this study. The optimal temperature and pH of recombinant AXE1s was 50 °C and 8.0 (except AXE1dC-CBM6), respectively. Cellulose-specific CBM1 in AXE1 obviously contributed to its catalytic action against substrates compared with AXE1dC. However, replacement of CBM1 with xylan-specific CBM4-2 significantly enhanced AXE1 thermostability and catalytic activity against soluble substrate 4-methylumbelliferyl acetate. Whereas replacements with xylan-specific CBM6 and CBM22-2 were more effective in enzymatic release of acetic acid from destarched wheat bran, NaClO2-treated wheat straw, and water-insoluble wheat arabinoxylan compared to AXE1. Moreover, replacement with CBM6 and CBM22-2 also resulted in higher degree releases of reducing sugar and acetic acid from different substrates when simultaneous hydrolysis with xylanase. A good linear relationship exists between the acetic acid and reducing sugar release. CONCLUSIONS Our findings suggested that the replacement with CBM6 and CBM22-2 not only significantly improved the catalysis efficiency of AXE1, but also increased its synergistic hydrolysis of different substrates with xylanase, indicating the significance of targeting effect in AXE1 catalysis mediated by xylan-specific CBMs.
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Affiliation(s)
- Shiping Liu
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Shaojun Ding
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China.
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Enzymatic diversity of the Clostridium thermocellum cellulosome is crucial for the degradation of crystalline cellulose and plant biomass. Sci Rep 2016; 6:35709. [PMID: 27759119 PMCID: PMC5069625 DOI: 10.1038/srep35709] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 10/03/2016] [Indexed: 01/18/2023] Open
Abstract
The cellulosome is a supramolecular multienzyme complex comprised of a wide variety of polysaccharide-degrading enzymes and scaffold proteins. The cellulosomal enzymes that bind to the scaffold proteins synergistically degrade crystalline cellulose. Here, we report in vitro reconstitution of the Clostridium thermocellum cellulosome from 40 cellulosomal components and the full-length scaffoldin protein that binds to nine enzyme molecules. These components were each synthesized using a wheat germ cell-free protein synthesis system and purified. Cellulosome complexes were reconstituted from 3, 12, 30, and 40 components based on their contents in the native cellulosome. The activity of the enzyme-saturated complex indicated that greater enzymatic variety generated more synergy for the degradation of crystalline cellulose and delignified rice straw. Surprisingly, a less complete enzyme complex displaying fewer than nine enzyme molecules was more efficient for the degradation of delignified rice straw than the enzyme-saturated complex, despite the fact that the enzyme-saturated complex exhibited maximum synergy for the degradation of crystalline cellulose. These results suggest that greater enzymatic diversity of the cellulosome is crucial for the degradation of crystalline cellulose and plant biomass, and that efficient degradation of different substrates by the cellulosome requires not only a different enzymatic composition, but also different cellulosome structures.
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Rosnow JJ, Anderson LN, Nair RN, Baker ES, Wright AT. Profiling microbial lignocellulose degradation and utilization by emergent omics technologies. Crit Rev Biotechnol 2016; 37:626-640. [PMID: 27439855 DOI: 10.1080/07388551.2016.1209158] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The use of plant materials to generate renewable biofuels and other high-value chemicals is the sustainable and preferable option, but will require considerable improvements to increase the rate and efficiency of lignocellulose depolymerization. This review highlights novel and emerging technologies that are being developed and deployed to characterize the process of lignocellulose degradation. The review will also illustrate how microbial communities deconstruct and metabolize lignocellulose by identifying the necessary genes and enzyme activities along with the reaction products. These technologies include multi-omic measurements, cell sorting and isolation, nuclear magnetic resonance spectroscopy (NMR), activity-based protein profiling, and direct measurement of enzyme activity. The recalcitrant nature of lignocellulose necessitates the need to characterize the methods microbes employ to deconstruct lignocellulose to inform new strategies on how to greatly improve biofuel conversion processes. New technologies are yielding important insights into microbial functions and strategies employed to degrade lignocellulose, providing a mechanistic blueprint in order to advance biofuel production.
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Affiliation(s)
- Joshua J Rosnow
- a Biological Sciences Division , Pacific Northwest National Laboratory , Richland , WA , USA
| | - Lindsey N Anderson
- a Biological Sciences Division , Pacific Northwest National Laboratory , Richland , WA , USA
| | - Reji N Nair
- a Biological Sciences Division , Pacific Northwest National Laboratory , Richland , WA , USA
| | - Erin S Baker
- a Biological Sciences Division , Pacific Northwest National Laboratory , Richland , WA , USA
| | - Aaron T Wright
- a Biological Sciences Division , Pacific Northwest National Laboratory , Richland , WA , USA
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