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Long L, Lin Q, Wang J, Ding S. Microbial α-L-arabinofuranosidases: diversity, properties, and biotechnological applications. World J Microbiol Biotechnol 2024; 40:84. [PMID: 38294733 DOI: 10.1007/s11274-023-03882-z] [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: 11/12/2023] [Accepted: 12/28/2023] [Indexed: 02/01/2024]
Abstract
Arabinoxylans (AXs) are hemicellulosic polysaccharides consisting of a linear backbone of β-1,4-linked xylose residues branched by high content of α-L-arabinofuranosyl (Araf) residues along with other side-chain substituents, and are abundantly found in various agricultural crops especially cereals. The efficient bioconversion of AXs into monosaccharides, oligosaccharides and/or other chemicals depends on the synergism of main-chain enzymes and de-branching enzymes. Exo-α-L-arabinofuranosidases (ABFs) catalyze the hydrolysis of terminal non-reducing α-1,2-, α-1,3- or α-1,5- linked α-L-Araf residues from arabinose-substituted polysaccharides or oligosaccharides. ABFs are critically de-branching enzymes in bioconversion of agricultural biomass, and have received special attention due to their application potentials in biotechnological industries. In recent years, the researches on microbial ABFs have developed quickly in the aspects of the gene mining, properties of novel members, catalytic mechanisms, methodologies, and application technologies. In this review, we systematically summarize the latest advances in microbial ABFs, and discuss the future perspectives of the enzyme research.
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Affiliation(s)
- Liangkun Long
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China.
- Jiangsu Province Key Laboratory of Green Biomass-Based Fuels and Chemicals, Nanjing, 210037, People's Republic of China.
| | - Qunying Lin
- Nanjing Institute for the Comprehensive Utilization of Wild Plants, China CO-OP, Nanjing, 211111, People's Republic of China
| | - Jing Wang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
| | - Shaojun Ding
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
- Jiangsu Province Key Laboratory of Green Biomass-Based Fuels and Chemicals, Nanjing, 210037, People's Republic of China
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Si Z, Cai Y, Zhao L, Han L, Wang F, Yang X, Gao X, Lu M, Liu W. Structure and function characterization of the α-L-arabinofuranosidase from the white-rot fungus Trametes hirsuta. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12561-w. [PMID: 37178306 DOI: 10.1007/s00253-023-12561-w] [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: 02/07/2023] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023]
Abstract
α-L-Arabinofuranosidases (Abfs) play a crucial role in the degradation of hemicelluloses, especially arabinoxylans (AX). Most of the available characterized Abfs are from bacteria, while fungi, as natural decomposers, contain Abfs with little attention given. An arabinofuranosidase (ThAbf1), belonging to the glycoside hydrolase 51 (GH51) family, from the genome of the white-rot fungus Trametes hirsuta, was recombinantly expressed, characterized, and functionally determined. The general biochemical properties showed that the optimal conditions for ThAbf1 were pH 6.0 and 50°C. In substrate kinetics assays, ThAbf1 preferred small fragment arabinoxylo-oligosaccharides (AXOS) and could surprisingly hydrolyze di-substituted 23,33-di-L-arabinofuranosyl-xylotriose (A2,3XX). It also synergized with commercial xylanase (XYL) and increased the saccharification efficiency of arabinoxylan. The crystal structure of ThAbf1 indicated the presence of an adjacent cavity next to the catalytic pocket which led to the ability of ThAbf1 to degrade di-substituted AXOS. The narrow binding pocket prevents ThAbf1 from binding larger substrates. These findings have strengthened our understanding of the catalytic mechanism of GH51 family Abfs and provided a theoretical foundation for the development of more efficient and versatile Abfs to accelerate the degradation and biotransformation of hemicellulose in biomass. KEY POINTS: • ThAbf1 from Trametes hirsuta degraded di-substituted arabinoxylo-oligosaccharide. • ThAbf1 performed detailed biochemical characterization and kinetics. • ThAbf1 structure has been obtained to illustrate the substrate specificity.
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Affiliation(s)
- Zhenyuan Si
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Yang Cai
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Lang Zhao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Lu Han
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China
| | - Feng Wang
- Simcere Pharmaceutical Group Limited, Nanjing, 210042, PR China
| | - Xiaobing Yang
- Biology and Medicine Department, Jiangsu Industrial Technology Research Institute, Nanjing, 210031, PR China
| | - Xiangdong Gao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China.
| | - Meiling Lu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China.
| | - Wei Liu
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, College of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009, PR China.
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Wang R, Zhang Y, Liu L, Yang J, Yuan H. Discovery of a bifunctional xylanolytic enzyme with arabinoxylan arabinofuranohydrolase-d3 and endo-xylanase activities and its application in the hydrolysis of cereal arabinoxylans. Microb Biotechnol 2023. [PMID: 37096984 DOI: 10.1111/1751-7915.14267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 04/26/2023] Open
Abstract
Xylanolytic enzymes, with both endo-xylanase and arabinoxylan arabinofuranohydrolase (AXH) activities, are attractive for the economically feasible conversion of recalcitrant arabinoxylan. However, their characterization and utilization of these enzymes in biotechnological applications have been limited. Here, we characterize a novel bifunctional enzyme, rAbf43A, cloned from a bacterial consortium that exhibits AXH and endo-xylanase activities. Hydrolytic pattern analyses revealed that the AXH activity belongs to AXHd3 because it attacked only the C(O)-3-linked arabinofuranosyl residues of double-substituted xylopyranosyl units of arabinoxylan and arabinoxylan-derived oligosaccharides, which are usually resistant to hydrolysis. The enzyme rAbf43A also liberated a series of xylo-oligosaccharides (XOSs) from beechwood xylan, xylohexaose and xylopentaose, indicating that rAbf43A exhibited endo-xylanase activity. Homology modelling based on AlphaFold2 and site-directed mutagenesis identified three non-catalytic residues (H161, A270 and L505) located in the substrate-binding pocket essential for its dual-functionality, while the mutation of A117 located in the -1 subsite to the proline residue only affected its endo-xylanase activity. Additionally, rAbf43A showed significant synergistic action with the bifunctional xylanase/feruloyl esterase rXyn10A/Fae1A from the same bacterial consortium on insoluble wheat arabinoxylan and de-starched wheat bran degradation. When rXyn10A/Fae1A was added to the rAbf43A pre-hydrolyzed reactions, the amount of released reducing sugars, xylose and ferulic acid increased by 9.43% and 25.16%, 189.37% and 93.54%, 31.39% and 32.30%, respectively, in comparison with the sum of hydrolysis products released by each enzyme alone. The unique characteristics of rAbf43A position it as a promising candidate not only for designing high-performance enzyme cocktails but also for investigating the structure-function relationship of GH43 multifunctional enzymes.
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Affiliation(s)
- Ruonan Wang
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
- College of Life Science, Luoyang Normal University, Luoyang, China
| | - Yu Zhang
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Liang Liu
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jinshui Yang
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Hongli Yuan
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
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Khamassi A, Dumon C. Enzyme synergy for plant cell wall polysaccharide degradation. Essays Biochem 2023; 67:521-531. [PMID: 37067158 DOI: 10.1042/ebc20220166] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/17/2023] [Accepted: 03/07/2023] [Indexed: 04/18/2023]
Abstract
Valorizing plant cell wall, marine and algal polysaccharides is of utmost importance for the development of the circular bioeconomy. This is because polysaccharides are by far the most abundant organic molecules found in nature with complex chemical structures that require a large set of enzymes for their degradation. Microorganisms produce polysaccharide-specific enzymes that act in synergy when performing hydrolysis. Although discovered since decades enzyme synergy is still poorly understood at the molecular level and thus it is difficult to harness and optimize. In the last few years, more attention has been given to improve and characterize enzyme synergy for polysaccharide valorization. In this review, we summarize literature to provide an overview of the different type of synergy involving carbohydrate modifying enzymes and the recent advances in the field exemplified by plant cell-wall degradation.
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Affiliation(s)
- Ahmed Khamassi
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Claire Dumon
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
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Ji S, Gavande PV, Choudhury B, Goyal A. Computational design and structure dynamics analysis of bifunctional chimera of endoxylanase from Clostridium thermocellum and xylosidase from Bacteroides ovatus. 3 Biotech 2023; 13:59. [PMID: 36714550 PMCID: PMC9877272 DOI: 10.1007/s13205-023-03482-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023] Open
Abstract
Development of chimeric enzymes by protein engineering can more efficiently contribute toward biomass conversion for bioenergy generation. Therefore, prior to experimental validation, a computational approach by modeling and molecular dynamic simulation can assess the structural and functional behavior of chimeric enzymes. In this study, a bifunctional chimera, CtXyn11A-BoGH43A comprising an efficient endoxylanase (CtXyn11A) from Clostridium thermocellum and xylosidase (BoGH43A) from Bacteroides ovatus was computationally designed and its binding and stability analysis with xylooligosaccharides were performed. The modeled chimera showed β-jellyroll fold for CtXyn11A and 5-bladed β-propeller fold for BoGH43A module. Stereo-chemical properties analyzed by Ramachandran plot showed 98.8% residues in allowed region, validating the modeled chimera. The catalytic residues identified by multiple sequence alignment were Glu94 and Glu184 for CtXyn11A and Asp229 and Glu384 for BoGH43A modules. CtXyn11A followed retaining-type, whereas BoGH43A enforced inverting-type of reaction mechanism during xylan hydrolysis as revealed by superposition and GH11 and GH43 familial analyses. Molecular docking studies showed binding energy, (ΔG) - 4.54 and - 4.18 kcal/mol for CtXyn11A and BoGH43A modules of chimera, respectively, with xylobiose, while - 3.94 and - 3.82 kcal/mol for CtXyn11A and BoGH43A modules of chimera, respectively, with xylotriose. MD simulation of CtXyn11A-BoGH43A complexed with xylobiose and xylotriose till 100 ns displayed stability by RMSD, compactness by R g and conformational stability by SASA analyses. The lowered values of RMSF in active-site residues, Glu94, Glu184, Asp229, Asp335 and Glu384 confirmed the efficient binding of chimera with xylobiose and xylotriose. These results were in agreement with the earlier experimental studies on CtXyn11A releasing xylooligosaccharides from xylan and BoGH43A releasing d-xylose from xylooligosaccharides and xylobiose. The chimera showed stronger affinity in terms of total short-range interaction energy; - 190 and - 121 kJ/mol for with xylobiose and xylotriose, respectively. The bifunctional chimera, CtXyn11A-BoGH43A showed stability and integrity with xylobiose and xylotriose. The designed chimera can be constructed and applied for efficient biomass conversion.
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Affiliation(s)
- Shyam Ji
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 India
| | - Parmeshwar Vitthal Gavande
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 India
| | - Bipasha Choudhury
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 India
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 India
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Kumar Saini J, Himanshu, Hemansi, Kaur A, Mathur A. Strategies to enhance enzymatic hydrolysis of lignocellulosic biomass for biorefinery applications: A review. BIORESOURCE TECHNOLOGY 2022; 360:127517. [PMID: 35772718 DOI: 10.1016/j.biortech.2022.127517] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Global interest in lignocellulosic biorefineries has increased in the recent past due to technological advancements in sustainable and cost-effective production of numerous commodity and speciality chemicals and fuels from renewable lignocellulosic biomass (LCB). As a result, the market value of biorefinery products has also increased over the time, with an estimated worth of USD 867.7 billion by 2025. However, biorefinery operations, especially enzymatic hydrolysis, suffer from many challenges that limits the cost-effectiveness of conversion of LCB. Therefore, it is essential to understand and address these challenges in future biorefineries. The paper focuses on recent trends and challenges in enzymatic hydrolysis of LCB during lignocellulosic biorefinery operation for greener synthesis of energy, fuels, chemicals and other high-value products. Insights into the gaps in knowledge and technological challenges have also been addressed together with focus on future research needs and perspectives of enzymatic hydrolysis of LCB for biorefinery applications.
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Affiliation(s)
- Jitendra Kumar Saini
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India.
| | - Himanshu
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
| | - Hemansi
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India; Research & Development Office, Ashoka University, Sonipat, Haryana PIN- 131029, India
| | - Amanjot Kaur
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
| | - Aayush Mathur
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
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Chen C, Qi K, Chi F, Song X, Feng Y, Cui Q, Liu YJ. Dissolved xylan inhibits cellulosome-based saccharification by binding to the key cellulosomal component of Clostridium thermocellum. Int J Biol Macromol 2022; 207:784-790. [PMID: 35351552 DOI: 10.1016/j.ijbiomac.2022.03.158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 03/01/2022] [Accepted: 03/24/2022] [Indexed: 12/16/2022]
Abstract
Polysaccharides derived from lignocellulose are promising sustainable carbon sources. Cellulosome is a supramolecular machine integrating multi-function enzymes for effective lignocellulose bio-saccharification. However, how various non-cellulose components of lignocellulose affect the cellulosomal saccharification is hitherto unclear. This study first investigated the stability and oxygen sensitivity of the cellulosome from Clostridium thermocellum during long-term saccharification process. Then, the differential inhibitory effects of non-cellulose components, including lignin, xylan, and arabinoxylan, on the cellulosome-based saccharification were determined. The results showed that lignin played inhibitory roles by non-productively adsorbing extracellular proteins of C. thermocellum. Differently, arabinoxylan preferred to bind with the cellulosomal components. Almost no adsorption of cellulosomal proteins on solid xylan was detected. Instead, xylan in water-dissolved form interacted with the cellulosomal proteins, especially the key exoglucanase Cel48S, leading to the xylan inhibitory effect. Compared to xylan, xylooligosaccharides influenced the cellulosome activity slightly. Hence, this work demonstrates that the timely hydrolysis or removal of dissolved xylan is important for cellulosome-based lignocellulose saccharification.
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Affiliation(s)
- Chao Chen
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Kuan Qi
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Fang Chi
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiaojin Song
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Ya-Jun Liu
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, PR China; Shandong Energy Institute, Qingdao 266101, PR China; Qingdao New Energy Shandong Laboratory; Dalian National Laboratory for Clean Energy, Qingdao 266101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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An Environmentally Friendly Approach for the Release of Essential Fatty Acids from Cereal By-Products Using Cellulose-Degrading Enzymes. BIOLOGY 2022; 11:biology11050721. [PMID: 35625449 PMCID: PMC9138263 DOI: 10.3390/biology11050721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 01/05/2023]
Abstract
Simple Summary Fatty acids, especially the representatives of essential mono- and polyunsaturated ones, play an important role in the human organism, as they are involved in the regulation of the immune and central nervous systems. Whole grain products are considered to be a rich source of multiple health-promoting phytochemicals, including fatty acids, where polyunsaturated fatty acids take prevalence over saturated ones. To improve the milling performance of grain and ensure the high-quality standards of flour, technologies presently utilized within the milling process, e.g., dehulling and debranning, generally aim at removing outer layers of cereal grain and result in substantial reduction of valuable nutrients along with loss of functionality. In spite of the relative abundance of valuable compounds in cereal bran, currently less than 10% of produced bran is used in the food industry. To valorize cereal bran for food and pharmaceutical applications, additional pre-treatment is required. Abstract The main intention of the present work was to investigate the ability of cellulose-degrading enzymes (C-DE) to release fatty acids (FAs) from complex matrices of cereal by-products during enzymatic hydrolysis (EH). For this purpose, three types of cereal bran (CB), i.e., wheat, rye, and oat, were used as lignocellulose substrates for three commercially available hydrolytic enzymes, i.e., Viscozyme L, Viscoferm, and Celluclast 1.5 L. The yield and composition of FAs after EH were assessed and compared with those obtained after either conventional Soxhlet extraction or after alkaline-assisted hydrolysis (A-AH) with 10% KOH in 80% MeOH and subsequent liquid–liquid extraction. The experimental results demonstrated that up to 6.3% and 43.7% higher total FA yield can be achieved by EH of rye bran using Celluclast 1.5 L than by A-AH and Soxhlet extraction, respectively. However, the application of Viscoferm for EH of wheat bran ensured up to 7.7% and 13.4% higher total FA yield than A-AH and Soxhlet extraction, respectively. The concentration of essential linolenic acid (C18:3) in lipids extracted after EH of rye bran with Celluclast 1.5 L was up to 24.4% and 57.0% higher than in lipids recovered by A-AH and Soxhlet extraction, respectively. In turn, the highest content of linolenic acid in wheat bran lipids was observed after EH with Viscoferm and Viscozyme L, ensuring 17.0% and 13.6% higher yield than after A-AH, respectively. SEM analysis confirmed substantial degradation of the CB matrix promoted by the ability of C-DE to act specifically on glycosidic bonds in cellulose and on xylosidic bonds in arabinoxylans, arabinans, and other arabinose-containing hemicelluloses. Structural alterations in cell integrity greatly contributed to the release of bound FAs and their better transfer into the extraction solvent. It has been shown that the proposed process of EH can be used for the efficient release of FAs from the CB matrix more sustainably and with a safer profile, thereby conveying greener production of FAs for certain purposes.
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Wu X, Zhang S, Zhao S, Dai L, Huang S, Liu X, Yu J, Wang L. Functional Specificity of Three α-Arabinofuranosidases from Different Glycoside Hydrolase Families in Aspergillus niger An76. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:5039-5048. [PMID: 35420820 DOI: 10.1021/acs.jafc.1c08388] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
α-l-Arabinofuranosidase (Abf), a debranching enzyme that can remove arabinose substituents from arabinoxylan, promotes the hydrolysis of hemicellulose in plant biomass. However, the functional specificity of Abfs from different glycoside hydrolase (GH) families on the digestion of arabinoxylan and their synergistic interaction with xylanase have not been systematically studied. In this work, we characterized three Abfs (AxhA, AbfB, and AbfC) from GH62, GH54, and GH51 families in Aspergillus niger An76. Quantitative transcriptional analysis showed that expression of the axhA gene was upregulated as a result of induction by xylose substrates, whereas expression of the abfB gene was mainly induced by arabinose. Recombinant AxhA, AbfB, and AbfC exhibited different hydrolytic performances. AxhA showed the highest catalytic activity toward wheat arabinoxylan (WAX) and tended to hydrolyze monosubstituted arabinofuranose units, whereas AbfB had higher catalytic activity on AN and debranched arabinan (DAN), having the ability to cope with mono- and disubstituted arabinofuranose units. Furthermore, AbfC had greater arabinofuranosidase activity on p-nitrophenyl-α-l-arabinofuranoside (pNP-AraF) than on other substrates. Moreover, three Abfs displayed obvious synergistic action with GH11 xylanase XynB against WAX and barley husk residues. The elucidation of the degradation mechanisms of Abfs will lay a theoretical foundation for the efficient industrialized transformation of arabinoxylans.
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Affiliation(s)
- Xiuyun Wu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
- State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266000, Shandong, China
| | - Shu Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
| | - Sha Zhao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
| | - Lin Dai
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
| | - Shuxia Huang
- State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266000, Shandong, China
| | - Xinli Liu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, Shandong, China
| | - Junhong Yu
- State Key Laboratory of Biological Fermentation Engineering of Beer, Qingdao 266000, Shandong, China
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, Shandong, China
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Du J, Liang J, Zhang X, Wang J, Li W, Song P, Feng X. Identifying the negative cooperation between major inhibitors of cellulase activity and minimizing their inhibitory potential during hydrolysis of acid-pretreated corn stover. BIORESOURCE TECHNOLOGY 2022; 343:126113. [PMID: 34648965 DOI: 10.1016/j.biortech.2021.126113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Soluble compounds produced during the enzymatic hydrolysis of lignocelluloses hampers cellulose conversion. Cellobiose and vanillin most severely inhibited the effect of cellobiohydrolase I. A concentration-dependent negative cooperative effect was found between cellobiose and vanillin. The combined inhibitory effect was about 83.5% of the cellobiose and 88.1% of the vanillin when their concentration was 20 mg/ml. However, the negative synergy could be eliminated by excessive enzyme loading. Differences in their binding sites on the catalytic domain of cellobiohydrolase I lead to negative synergistic inhibition, which should be considered in devising strategies to alleviate this effect. Combined β-glucosidase and PEG addition at an appropriate dose was feasible to balance cost and hydrolytic efficiency. To achieve efficient hydrolysis, especially at high solid concentrations, it is important to understand the synergistic inhibition between these inhibitors.
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Affiliation(s)
- Jian Du
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang 277160, China.
| | - Jingrui Liang
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang 277160, China
| | - Xiujun Zhang
- College of Biological Science and Technology, Jinan University, Jinan 250024, China
| | - Jinglong Wang
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang 277160, China
| | - Wei Li
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang 277160, China
| | - Peixue Song
- College of City and Architectural Engineering, Zaozhuang University, Zaozhuang 277160, China
| | - Xiaohui Feng
- College of Food Science and Pharmaceutical Engineering, Zaozhuang University, Zaozhuang 277160, China
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11
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Lignocellulose-Degrading Enzymes: A Biotechnology Platform for Ferulic Acid Production from Agro-Industrial Side Streams. Foods 2021; 10:foods10123056. [PMID: 34945607 PMCID: PMC8701750 DOI: 10.3390/foods10123056] [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: 11/05/2021] [Revised: 11/28/2021] [Accepted: 12/03/2021] [Indexed: 01/30/2023] Open
Abstract
Biorefining by enzymatic hydrolysis (EH) of lignocellulosic waste material due to low costs and affordability has received enormous interest amongst scientists as a potential strategy suitable for the production of bioactive ingredients and chemicals. In this study, a sustainable and eco-friendly approach to extracting bound ferulic acid (FA) was demonstrated using single-step EH by a mixture of lignocellulose-degrading enzymes. For comparative purposes of the efficiency of EH, an online extraction and analysis technique using supercritical fluid extraction-supercritical fluid chromatography-mass spectrometry (SFE-SFC-MS) was performed. The experimental results demonstrated up to 369.3 mg 100 g-1 FA release from rye bran after 48 h EH with Viscozyme L. The EH of wheat and oat bran with Viscoferm for 48 h resulted in 255.1 and 33.5 mg 100 g-1 of FA, respectively. The release of FA from bran matrix using supercritical fluid extraction with carbon dioxide and ethanol as a co-solvent (SFE-CO2-EtOH) delivered up to 464.3 mg 100 g-1 of FA, though the extractability varied depending on the parameters used. The 10-fold and 30-fold scale-up experiments confirmed the applicability of EH as a bioprocessing method valid for the industrial scale. The highest yield of FA in both scale-up experiments was obtained from rye bran after 48 h of EH with Viscozyme L. In purified extracts, the absence of xylose, arabinose, and glucose as the final degradation products of lignocellulose was proven by high-performance liquid chromatography with refractive index detection (HPLC-RID). Up to 94.0% purity of FA was achieved by solid-phase extraction (SPE) using the polymeric reversed-phase Strata X column and 50% EtOH as the eluent.
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12
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Agrawal R, Verma A, Singhania RR, Varjani S, Di Dong C, Kumar Patel A. Current understanding of the inhibition factors and their mechanism of action for the lignocellulosic biomass hydrolysis. BIORESOURCE TECHNOLOGY 2021; 332:125042. [PMID: 33813178 DOI: 10.1016/j.biortech.2021.125042] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 06/12/2023]
Abstract
Biorefining of lignocellulosic biomass is a relatively new concept but it has strong potential to develop and partially replace the fossil derived fuels and myriad of value products to subsequently reduce the greenhouse gas emissions. However, the energy and cost intensive process of releasing the entrapped fermentable sugars is a major challenge for its commercialization. Various factors playing a detrimental role during enzymatic hydrolysis of biomass are inherent recalcitrance of lignocellulosic biomass, expensive enzymes, sub-optimal enzyme composition, lack of synergistic activity and enzyme inhibition caused by various inhibitors. The current study investigated the mechanism of enzyme inhibition during lignocellulosic biomass saccharification especially at high solid loadings. These inhibition factors are categorized into physio-chemical factors, water-soluble and -insoluble enzyme inhibitors, oligomers and enzyme-lignin binding. Furthermore, different approaches are proposed to alleviate the challenges and improve the enzymatic hydrolysis efficiency such as supplementation with surfactants, synergistic catalytic/non-catalytic proteins, and bioprocess modifications.
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Affiliation(s)
- Ruchi Agrawal
- The Energy and Resources Institute, TERI Gram, Gwal Pahari, Gurugram, Haryana, India
| | - Amit Verma
- College of Basic Science and Humanities, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar - 385506 (Banaskantha), Gujarat, India
| | - Reeta Rani Singhania
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar, Gujarat 382010, India
| | - Cheng Di Dong
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Anil Kumar Patel
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan.
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13
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Mafa MS, Malgas S, Pletschke BI. Feruloyl esterase (FAE-1) sourced from a termite hindgut and GH10 xylanases synergy improves degradation of arabinoxylan. AMB Express 2021; 11:21. [PMID: 33464449 PMCID: PMC7815865 DOI: 10.1186/s13568-021-01180-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 01/05/2021] [Indexed: 12/26/2022] Open
Abstract
Cereal feedstocks have high arabinoxylan content as their main hemicellulose, which is linked to lignin by hydroxycinnamic acids such as ferulic acid. The ferulic acid is linked to arabinoxylan by ester bonds, and generally, the high substitution of ferulic acid leads to a loss of activity of xylanases targeting the arabinoxylan. In the current study, a feruloyl esterase (FAE-1) from a termite hindgut bacteria was functionally characterised and used in synergy with xylanases during xylan hydrolysis. The FAE-1 displayed temperature and pH optima of 60 ℃ and 7.0, respectively. FAE-1 did not release reducing sugars from beechwood xylan (BWX), wheat arabinoxylan (WAX) and oat spelt xylan (OX), however, displayed high activity of 164.74 U/mg protein on p-nitrophenyl-acetate (pNPA). In contrast, the GH10 xylanases; Xyn10 and XT6, and a GH11 xylanase, Xyn2A, showed more than two-fold increased activity on xylan substrates with low sidechain substitutions; BWX and OX, compared to the highly branched substrate, WAX. Interestingly, the FAE-1 and GH10 xylanases (Xyn10D and XT6) displayed a degree of synergy (DS) that was higher than 1 in all enzyme loading combinations during WAX hydrolysis. The 75%XT6:25%FAE-1 synergistic enzyme combination increased the release of reducing sugars by 1.34-fold from WAX compared to the control, while 25%Xyn10D:75%FAE-1 synergistic combination released about 2.1-fold of reducing sugars from WAX compared to controls. These findings suggest that FAE-1 can be used in concert with xylanases, particularly those from GH10, to efficiently degrade arabinoxylans contained in cereal feedstocks for various industrial settings such as in animal feeds and baking.
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Poria V, Saini JK, Singh S, Nain L, Kuhad RC. Arabinofuranosidases: Characteristics, microbial production, and potential in waste valorization and industrial applications. BIORESOURCE TECHNOLOGY 2020; 304:123019. [PMID: 32089440 DOI: 10.1016/j.biortech.2020.123019] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/09/2020] [Accepted: 02/11/2020] [Indexed: 05/15/2023]
Abstract
Alpha-L-arabinofuranoside arabinofuranohydrolase (ARA), more commonly known as alpha-L-arabinofuranosidase (E.C. number 3.2.1.55), is a hydrolytic enzyme, catalyzing the cleavage of alpha-L-arabinose by acting on the non-reducing ends of alpha-L-arabinofuranosides, alpha-L-arabinans containing (1,3)- and/or (1,5)-linked arabinoxylans and arabinogalactans. ARA functions as debranching enzyme removing arabinose substituents from arabinoxylan and arabinoxylooligomers, thereby, boosting the hydrolysis of arabinoxylan fraction of hemicellulose and improving bioconversion of lignocellulosic biomass. Previously, comprehensive information on this enzyme has not been reviewed thoroughly. Therefore, the main aim of this review is to highlight the important properties of this interesting enzyme, microorganisms used for its production, and enhanced production using genetic engineering approach. An account on synergism with other biomass hydrolyzing enzymes and various industrial applications of this enzyme has also been provided along with an outlook on further research and development.
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Affiliation(s)
- Vikram Poria
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
| | - Jitendra Kumar Saini
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India
| | - Surender Singh
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana PIN-123031, India; Division of Microbiology, Indian Agricultural Research Institute, New Delhi PIN-110012, India.
| | - Lata Nain
- Division of Microbiology, Indian Agricultural Research Institute, New Delhi PIN-110012, India
| | - Ramesh Chander Kuhad
- Central University of Haryana, Mahendergarh, Haryana PIN-123031, India; Lignocellulose Biotechnology Laboratory, Department of Microbiology, University of Delhi South Campus, New Delhi PIN-110021, India
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15
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Wu Y, Chen Y, Lu Y, Hao H, Liu J, Huang R. Structural features, interaction with the gut microbiota and anti-tumor activity of oligosaccharides. RSC Adv 2020; 10:16339-16348. [PMID: 35498870 PMCID: PMC9053055 DOI: 10.1039/d0ra00344a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/16/2020] [Indexed: 12/11/2022] Open
Abstract
Some oligosaccharides are regarded as biological constituents with benefits to human health in an indirect way. They enter the intestinal tract to be fermented by the gut microbiota, causing changes in the abundance and composition of the gut microbiota and producing fermentation products such as short-chain fatty acids (SCFAs). In this review, the structural features and biological activities of eight common natural oligosaccharides were summarized, including human milk oligosaccharides (HMOS), xylo-oligosaccharides (XOS), arabinoxylo-oligosaccharides (AXOS), isomaltooligosaccharides (IMOS), chitin oligosaccharides (NACOS), mannan-oligosaccharides (MOS), galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS). Furthermore, XOS were selected to explain the anti-tumor mechanism mediated by gut microbiota. The review aims to reveal primary structural features of natural functional oligosaccharides related to the biological activities and also provide an explanation of the anti-tumor activity of functional oligosaccharides mediated by the gut microbiota. Some oligosaccharides are regarded as biological constituents with benefits to human health in an indirect way.![]()
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Affiliation(s)
- Yulin Wu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University Guangzhou 510642 China +86 20 8528 3448 +86 7592388240
| | - Yinning Chen
- Guangdong Polytechnic College 526100 Zhaoqing China
| | - Yingfang Lu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University Guangzhou 510642 China +86 20 8528 3448 +86 7592388240
| | - Huili Hao
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University Guangzhou 510642 China +86 20 8528 3448 +86 7592388240
| | - Jun Liu
- Laboratory of Pathogenic Biology, Guangdong Medical University Zhanjiang 524023 China
| | - Riming Huang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University Guangzhou 510642 China +86 20 8528 3448 +86 7592388240
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16
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Valadares F, Gonçalves TA, Damasio A, Milagres AM, Squina FM, Segato F, Ferraz A. The secretome of two representative lignocellulose-decay basidiomycetes growing on sugarcane bagasse solid-state cultures. Enzyme Microb Technol 2019; 130:109370. [PMID: 31421724 DOI: 10.1016/j.enzmictec.2019.109370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/27/2019] [Accepted: 07/02/2019] [Indexed: 12/14/2022]
Abstract
Secretome evaluations of lignocellulose-decay basidiomycetes can reveal new enzymes in selected fungal species that degrade specific substrates. Proteins discovered in such studies can support biorefinery development. Brown-rot (Gloeophyllum trabeum) and white-rot (Pleurotus ostreatus) fungi growing in sugarcane bagasse solid-state cultures produced 119 and 63 different extracellular proteins, respectively. Several of the identified enzymes are suitable for in vitro biomass conversion, including a range of cellulases (endoglucanases, cellobiohydrolases and β-glucosidases), hemicellulases (endoxylanases, α-arabinofuranosidases, α-glucuronidases and acetylxylan esterases) and carbohydrate-active auxiliary proteins, such as AA9 lytic polysaccharide monooxygenase, AA1 laccase and AA2 versatile peroxidase. Extracellular oxalate decarboxylase was also detected in both fungal species, exclusively in media containing sugarcane bagasse. Interestingly, intracellular AA6 quinone oxidoreductases were also exclusively produced under sugarcane bagasse induction in both fungi. These enzymes promote quinone redox cycling, which is used to produce Fenton's reagents by lignocellulose-decay fungi. Hitherto undiscovered hypothetical proteins that are predicted in lignocellulose-decay fungi genomes appeared in high relative abundance in the cultures containing sugarcane bagasse, which suggests undisclosed, new biochemical mechanisms that are used by lignocellulose-decay fungi to degrade sugarcane biomass. In general, lignocellulose-decay fungi produce a number of canonical hydrolases, as well as some newly observed enzymes, that are suitable for in vitro biomass digestion in a biorefinery context.
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Affiliation(s)
- Fernanda Valadares
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil
| | - Thiago A Gonçalves
- Programa de Processos Tecnológicos e Ambientais, Universidade de Sorocaba, 18023-000 Sorocaba, SP, Brazil; Institute of Biology, University of Campinas (UNICAMP), 13080-655, Campinas, SP, Brazil
| | - André Damasio
- Institute of Biology, University of Campinas (UNICAMP), 13080-655, Campinas, SP, Brazil
| | - Adriane Mf Milagres
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil
| | - Fabio M Squina
- Programa de Processos Tecnológicos e Ambientais, Universidade de Sorocaba, 18023-000 Sorocaba, SP, Brazil
| | - Fernando Segato
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil
| | - André Ferraz
- Departamento de Biotecnologia, Escola de Engenharia de Lorena, Universidade de São Paulo, 12602-810, Lorena, SP, Brazil.
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