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Singh YR, Thakur A, Fontes CMGA, Goyal A. A novel thermophilic recombinant obligate xylobiohydrolase (AcGH30A) from Acetivibrio clariflavus orchestrates the deconstruction of xylan polysaccharides. Carbohydr Polym 2024; 340:122295. [PMID: 38858006 DOI: 10.1016/j.carbpol.2024.122295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/15/2024] [Accepted: 05/18/2024] [Indexed: 06/12/2024]
Abstract
GH30 xylobiohydrolases, an expanding enzyme category, need deeper insights for optimal use. The primary aim of this study was to characterize a new xylobiohydrolase, AcGH30A of GH30 family from Acetivibrio clariflavus. The gene encoding AcGH30A was cloned using pET28a(+) vector and expressed in E. coli BL21(DE3) cells. AcGH30A was purified by immobilized metal-ion affinity chromatography. SDS-PAGE analysis of AcGH30A showed molecular mass of ~58 kDa. AcGH30A showed optimum temperature 80 °C and optimum pH 7.0. AcGH30A was stable (maintaining >80 % of control activity) in pH range, 4-7 and temperature range, 30 °C -70 °C when incubated for 90 min. AcGH30A displayed melting temperature, 72 °C and half-life, 21 days at 4 °C. The enzyme activity of AcGH30A was enhanced by 10 mM Ca2+ and Mg2+ ions by 25 % and 21 %, respectively, whereas 10 mM Co2+, Zn2+, Fe2+, and Cu2+ ions significantly reduced it. AcGH30A showed activity against various xylan polysaccharides displaying highest Vmax, 139 U.mg-1 and KM, 0.71 mg.ml-1 against 4-O-methyl glucuronoxylan under optimum conditions. TLC, HPLC and LC-MS analyses of AcGH30A hydrolyzed products from xylan substrates revealed the release of sole product, xylobiose, confirming it as an obligate xylobiohydrolase. AcGH30A being a highly thermostable enzyme can be potentially utlilized in various biotechnological applications.
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Affiliation(s)
- Yumnam Robinson Singh
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Guwahati, Assam 781039, India
| | - Abhijeet Thakur
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Guwahati, Assam 781039, India
| | - Carlos M G A Fontes
- NZYTech - Genes & Enzymes, Estrada do Paço do Lumiar, Campus do Lumiar, Edifício E - R/C, 1649-038 Lisbon, Portugal; CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, Guwahati, Assam 781039, India.
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2
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Tagade A, Sawarkar AN. Valorization of millet agro-residues for bioenergy production through pyrolysis: Recent inroads, technological bottlenecks, possible remedies, and future directions. BIORESOURCE TECHNOLOGY 2023:129335. [PMID: 37343798 DOI: 10.1016/j.biortech.2023.129335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/23/2023]
Abstract
Millets are receiving increasing attention, lately, in view of their preeminent agronomic traits, nutritional significance, and renewed emphasis on highlighting their health benefits through national and international programs. As a consequence, a variety of millets are being cultivated in different parts of the world resulting in significant amount of millet agro-residues. Present study comprehends critical analysis of reported investigations on pyrolysis of different millet agro-residues encompassing (i) physico-chemical characterization (ii) kinetics and thermodynamic parameters (iii) reactors employed and (iv) relationship between the reaction conditions and characteristics of millets-derived biochar and its prospective applications. Based on the analysis of reported investigations, specific research gaps have been figured out. Finally, future directions for leveraging the energy potential of millet agro-residues are also discussed. The analysis elucidated is expected to be useful for the researchers for making further inroads pertaining to sustainable utilization of millet agro-residues in tandem with other commonly employed agro-residues.
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Affiliation(s)
- Ankita Tagade
- Department of Chemical Engineering, Motilal Nehru National Institute of Technology Allahabad, Prayagraj 211004, Uttar Pradesh, India
| | - Ashish N Sawarkar
- Department of Chemical Engineering, Motilal Nehru National Institute of Technology Allahabad, Prayagraj 211004, Uttar Pradesh, India.
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3
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Haldar D, Shabbirahmed AM, Mahanty B. Multivariate regression and artificial neural network modelling of sugar yields from acid pretreatment and enzymatic hydrolysis of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2023; 370:128519. [PMID: 36563864 DOI: 10.1016/j.biortech.2022.128519] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/13/2022] [Accepted: 12/18/2022] [Indexed: 05/26/2023]
Abstract
Reducing sugar generation from lignocellulosic biomass (LCB) is closely linked with biomass characteristics, pretreatment and enzymatic hydrolysis conditions. In this study curated experimental data from literature was used to develop multivariate regression and artificial neural network (ANN) model considering nine predictors (i.e., cellulose, hemicellulose, lignin content, cellulose-lignin ratio, acid concentration, temperature, time, pretreatment severity, and enzyme concentration). Selected reduced polynomial model (R2: 0.891, Adj. R2: 0.849) suggests positive influence of acid and enzyme, while negative influence of treatment severity, temperature and time on reducing sugar generation. Genetic algorithm-optimized ANN model offered excellent fitness for LCB hydrolysis on training (R2: 0.997), validation (R2: 0.984), and test sets (R2: 0.967). Sensitivity analysis of the ANN predictors suggests lignin and to some extent hemicellulose contents can be inhibitory. Though polynomial models can have simple interpretation, use of optimized ANN offers better predictability in dataset with diverse biomass compositions.
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Affiliation(s)
- Dibyajyoti Haldar
- Department of Biotechnology, Karunya Institute of Technology and Sciences, Coimbatore 641114, India
| | | | - Biswanath Mahanty
- Department of Biotechnology, Karunya Institute of Technology and Sciences, Coimbatore 641114, India.
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4
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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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Chen L, Qu Z, Yu W, Zheng L, Qiao H, Wang D, Wei B, Zhao Z. Comparative genomic and transcriptome analysis of Bacillus velezensis CL-4 fermented corn germ meal. AMB Express 2023; 13:10. [PMID: 36683079 PMCID: PMC9868226 DOI: 10.1186/s13568-023-01510-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/08/2023] [Indexed: 01/24/2023] Open
Abstract
Bacillus, an excellent organic-degrading agent, can degrade lignocellulose. Notably, some B. velezensis strains encode lignocellulases. However, their ability to degrade lignocellulose in fermented feed is not much appreciated. This study performed a comparative genomic analysis of twenty-three B. velezensis strains to find common carbohydrate-active enzymes (CAZymes) encoding genes and evaluated their potential to degrade lignocellulose. The comparative genomic and CAZyme database-based analyses identified several potential CAZymes genes that degrade cellulose (GH1, GH4, GH5, GH13, GH16, GH32, PL1, and PL9), hemicellulose (GH11, GH26, GH43, GH51, and CE3) and lignin (AA4, AA6, AA7, and AA10). Furthermore, Illumina RNA-seq transcriptome analysis revealed the expression of more than 1794 genes in B. velezensis CL-4 fermented corn germ meal at 48 h (FCGM 48 h). Gene ontology analysis of expressed genes revealed their enrichment in hydrolase activity (breaking the glycosyl bonds during carbohydrate metabolism), indicating the upregulation of CAZymes. In total, 58 differentially upregulated CAZymes-encoding genes were identified in FCGM 48 h compared to FCGM 0 h. The upregulated CAZymes-encoding genes were related to cellulose (6-phospho-β-galactosidase and 6-phospho-α-glucosidase), starch (α-glucosidase and α-amylase), pectin (pectin lyase), and hemicellulose (arabinan endo-1,5-α-L-arabinosidase, xylan 1,4-beta-xylosidase, α-N-arabinofuranosidase, and acetyl xylan esterase). Importantly, arabinoxylan degradation mainly occurred in FCGM 48 h, followed by partial degradation of cellulose, pectin, and starch. This study can support the development of enzymatic cocktails for the solid-state fermented feed (SFF).
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Affiliation(s)
- Long Chen
- grid.464388.50000 0004 1756 0215Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100 Jilin China
| | - Zihui Qu
- grid.464388.50000 0004 1756 0215Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100 Jilin China
| | - Wei Yu
- grid.464388.50000 0004 1756 0215Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100 Jilin China
| | - Lin Zheng
- grid.464388.50000 0004 1756 0215Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100 Jilin China
| | - Haixin Qiao
- Information Application Department, Jilin Intellectual Property Protection Center, Changchun, 130000 China
| | - Dan Wang
- grid.464388.50000 0004 1756 0215Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100 Jilin China
| | - Bingdong Wei
- grid.464388.50000 0004 1756 0215Institute of Animal Nutrition and Feed, Jilin Academy of Agricultural Sciences, No. 186 Dong Xinghua Street, Gongzhuling, 136100 Jilin China
| | - Zijian Zhao
- grid.464388.50000 0004 1756 0215Institute of Agro-Food Technology, Jilin Academy of Agricultural Sciences, No. 1366 Cai Yu Street, Changchun, 130033 Jilin Province China
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6
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Gavande PV, Nath P, Kumar K, Ahmed N, Fontes CMGA, Goyal A. Highly efficient, processive and multifunctional recombinant endoglucanase RfGH5_4 from Ruminococcus flavefaciens FD-1 v3 for recycling lignocellulosic plant biomasses. Int J Biol Macromol 2022; 209:801-813. [PMID: 35421411 DOI: 10.1016/j.ijbiomac.2022.04.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/18/2022] [Accepted: 04/08/2022] [Indexed: 11/26/2022]
Abstract
Gene encoding endoglucanase, RfGH5_4 from R. flavefaciens FD-1 v3 was cloned, expressed in Escherichia coli BL21(DE3) cells and purified. RfGH5_4 showed molecular size 41 kDa and maximum activity at pH 5.5 and 55 °C. It was stable between pH 5.0-8.0, retaining 85% activity and between 5 °C-45 °C, retaining 75% activity, after 60 min. RfGH5_4 displayed maximum activity (U/mg) against barley β-D-glucan (665) followed by carboxymethyl cellulose (450), xyloglucan (343), konjac glucomannan (285), phosphoric acid swollen cellulose (86), beechwood xylan (21.7) and carob galactomannan (16), thereby displaying the multi-functionality. Catalytic efficiency (mL.mg-1 s-1) of RfGH5_4 against carboxymethyl cellulose (146) and konjac glucomannan (529) was significantly high. TLC and MALDI-TOF-MS analyses of RfGH5_4 treated hydrolysates of cellulosic and hemicellulosic polysaccharides displayed oligosaccharides of degree of polymerization (DP) between DP2-DP11. TLC, HPLC and Processivity-Index analyses revealed RfGH5_4 to be a processive endoglucanase as initially, for 30 min it hydrolysed cellulose to cellotetraose followed by persistent release of cellotriose and cellobiose. RfGH5_4 yielded sufficiently high Total Reducing Sugar (TRS, mg/g) from saccharification of alkali pre-treated sorghum (72), finger millet (62), sugarcane bagasse (38) and cotton (27) in a 48 h saccharification reaction. Thus, RfGH5_4 can be considered as a potential endoglucanase for renewable energy applications.
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Affiliation(s)
- Parmeshwar Vitthal Gavande
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Priyanka Nath
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Krishan Kumar
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Nazneen Ahmed
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Carlos M G A Fontes
- CIISA - Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal; NZYTech - Genes & Enzymes, Estrada do Paço do Lumiar, Campus do Lumiar, Edifício, Lisbon, Portugal
| | - Arun Goyal
- Department of Biosciences and Bioengineering, Carbohydrate Enzyme Biotechnology Laboratory, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
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7
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Long L, Sun L, Liu Z, Lin Q, Wang J, Ding S. Functional characterization of a GH62 family α-L-arabinofuranosidase from Eupenicillium parvum suitable for monosaccharification of corncob arabinoxylan in combination with key enzymes. Enzyme Microb Technol 2021; 154:109965. [PMID: 34933174 DOI: 10.1016/j.enzmictec.2021.109965] [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: 08/16/2021] [Revised: 11/20/2021] [Accepted: 12/06/2021] [Indexed: 11/30/2022]
Abstract
Corncob rich in arabinoxylan is an important raw material widely used in bio-refinery. Complete saccharification of arabinoxylan depends on the synergism of different enzymes including α-L-arabinofuranosidase (ABF). This study aimed to investigate the functional characteristics of a new ABF EpABF62A belonging to glycoside hydrolase (GH) 62 family from the fungus Eupenicillium parvum, and to explore its potential in the saccharification of corncob arabinoxylan. The recombinant EpABF62A showed high activity against wheat arabinoxylan and rye arabinoxylan, with the optimal temperature of 55 °C and pH of 4.5. The protein contains an N-terminal cellulose-binding domain family 1 (CBM_1) domain, and displayed a 59.5% absorption rate to phosphoric acid swollen cellulose. Regioselectivity analysis indicated that the enzyme selectively removed α-1,2 or α-1,3 linked arabinofuranosyl residues on mono-substituted xylose residues on arabinoxylan. Corncob arabinoxylans (CAX1 or CAX2) with different (low or high) branching degrees were extracted from the raw material by alkaline hydrogen peroxide pretreatment and graded ethanol precipitation. Single EpABF62A removed 69.5% or 67.1% arabinose from CAX1 or CAX2, respectively. EpABF62A combined with a GH10 xylanase, a GH43 β-D-xylosidase and a GH67 α-glucuronidase released 75.0% or 64.5% xylose from CAX1 or CAX2, respectively. The addition of the four hemicellulases enhanced the saccharification the solid fraction of the pretreated corncob by the commercial cellulase Cellic® CTec2, and the conversion ratios of glucose, xylose and arabinose were up to 94.0%, 91.8% and 82.6%, respectively.
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Affiliation(s)
- Liangkun Long
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, Nanjing 210037, China
| | - Lu Sun
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Zhen Liu
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Qunying Lin
- Nanjing Institute for the Comprehensive Utilization of Wild Plants, Nanjing 211111, China
| | - Jing Wang
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China
| | - Shaojun Ding
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Jiangsu Key Lab for the Chemistry & Utilization of Agricultural and Forest Biomass, Nanjing 210037, China.
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8
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Karuppasamy Vikraman V, Praveen Kumar D, Boopathi G, Subramanian P. Kinetic and thermodynamic study of finger millet straw pyrolysis through thermogravimetric analysis. BIORESOURCE TECHNOLOGY 2021; 342:125992. [PMID: 34583115 DOI: 10.1016/j.biortech.2021.125992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Pyrolysis kinetics of finger millet straw (FMS) was studied using a thermogravimetric analyzer under N2 environment. Physico-chemical characteristics of FMS were comparable with the established pyrolysis feedstocks. FMS thermally decomposed in three stages: drying, active pyrolysis, and char formation resulting in 70.37% overall weight loss. Average activation energy determined by Friedman and Starink methods was 177.80 and 172.18 kJ mol-1, respectively. Frequency factor was found to be in the range of 108 to 1029. Reaction pathway followed diffusion, nucleation, and order-based mechanisms. The pyrolysis of FMS was characterized by empirical modeling and predicted well with model adequacy of 97.55%. Thermodynamic parameters (ΔG and ΔH) revealed the non-spontaneous and endothermic nature of FMS pyrolysis. The biochar obtained at multiple heating rates were characterized for its physicochemical, functional, and morphological characteristics. The kinetic and thermodynamic analyses illustrate the feasibility of exploiting finger millet straw as a pyrolysis feedstock to derive biofuels.
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Affiliation(s)
- V Karuppasamy Vikraman
- Department of Renewable Energy Engineering, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641003, India
| | - D Praveen Kumar
- Department of Renewable Energy Engineering, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641003, India
| | - G Boopathi
- Department of Agricultural Engineering, Amrita School of Agricultural Sciences, Amrita Vishwa Vidyapeetham, Coimbatore, Tamil Nadu 642109, India.
| | - P Subramanian
- Department of Renewable Energy Engineering, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641003, India
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Thakur A, Sharma A, Khaire KC, Moholkar VS, Pathak P, Bhardwaj NK, Goyal A. Two-Step Saccharification of the Xylan Portion of Sugarcane Waste by Recombinant Xylanolytic Enzymes for Enhanced Xylose Production. ACS OMEGA 2021; 6:11772-11782. [PMID: 34056331 PMCID: PMC8153997 DOI: 10.1021/acsomega.1c01262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/08/2021] [Indexed: 05/10/2023]
Abstract
Sugarcane bagasse (SB) and sugarcane trash (SCT) containing 30% hemicellulose content are the waste from the sugarcane industry. Hemicellulose being heterogeneous, more complex, and less abundant than cellulose remains less explored. The optimized conditions for the pretreatment of SB and SCT for maximizing the delignification are soaking in aqueous ammonia (SAA), 18.5 wt %, followed by heating at 70 °C for 14 h. The optimization of hydrolysis of SAA pretreated (ptd) SB and SCT by the Box-Behnken design in the first step of saccharification by xylanase (CtXyn11A) and α-l-arabinofuranosidase (PsGH43_12) resulted in the total reducing sugar (TRS) yield of xylooligosaccharides (TRS(XOS)) of 93.2 mg/g ptd SB and 85.1 mg/g ptd SCT, respectively. The second step of saccharification by xylosidase (BoGH43) gave the TRS yield of 164.7 mg/g ptd SB and 147.2 mg/g ptd SCT. The high-performance liquid chromatography analysis of hydrolysate obtained after the second step of saccharification showed 69.6% xylan-to-xylose conversion for SB and 64.1% for SCT. This study demonstrated the optimization of the pretreatment method and of the enzymatic saccharification by recombinant xylanolytic enzymes, resulting in the efficient saccharification of ptd hemicellulose to TRS by giving 73.5% conversion for SB and 71.1% for SCT. These optimized conditions for the pretreatment and saccharification of sugarcane waste can also be used at a large scale.
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Affiliation(s)
- Abhijeet Thakur
- Carbohydrate
Enzyme Biotechnology Laboratory, Department of Biosciences
and Bioengineering, Center for Energy, Department of Chemical Engineering, Indian
Institute of Technology Guwahati, Guwahati 781039, India
| | - Aakash Sharma
- Carbohydrate
Enzyme Biotechnology Laboratory, Department of Biosciences
and Bioengineering, Center for Energy, Department of Chemical Engineering, Indian
Institute of Technology Guwahati, Guwahati 781039, India
| | - Kaustubh Chandrakant Khaire
- Carbohydrate
Enzyme Biotechnology Laboratory, Department of Biosciences
and Bioengineering, Center for Energy, Department of Chemical Engineering, Indian
Institute of Technology Guwahati, Guwahati 781039, India
| | - Vijayanand Suryakant Moholkar
- Carbohydrate
Enzyme Biotechnology Laboratory, Department of Biosciences
and Bioengineering, Center for Energy, Department of Chemical Engineering, Indian
Institute of Technology Guwahati, Guwahati 781039, India
| | - Puneet Pathak
- Avantha
Centre for Industrial Research & Development, Paper Mill Campus, Yamuna Nagar, Haryana 135001, India
| | - Nishi Kant Bhardwaj
- Avantha
Centre for Industrial Research & Development, Paper Mill Campus, Yamuna Nagar, Haryana 135001, India
| | - Arun Goyal
- Carbohydrate
Enzyme Biotechnology Laboratory, Department of Biosciences
and Bioengineering, Center for Energy, Department of Chemical Engineering, Indian
Institute of Technology Guwahati, Guwahati 781039, India
- E-mail: . Phone: +91-361-258-2208
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10
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Chen L, Yi Z, Fang Y, Jin Y, He K, Xiao Y, Zhao D, Luo H, He H, Sun Q, Zhao H. Biochemical and synergistic properties of a novel alpha-amylase from Chinese nong-flavor Daqu. Microb Cell Fact 2021; 20:80. [PMID: 33827572 PMCID: PMC8028695 DOI: 10.1186/s12934-021-01571-w] [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: 12/16/2020] [Accepted: 03/25/2021] [Indexed: 11/10/2022] Open
Abstract
Background Daqu is the most important fermentation starter for Chinese liquor, with large number of microbes and enzymes being openly enriched in the Daqu system over thousands of years. However, only a few enzymes have been analyzed with crude protein for total liquefying power and saccharifying power of Daqu. Therefore, the complex enzymatic system present in Daqu has not been completely characterized. Moreover, their pivotal and complicated functions in Daqu are completely unknown. Results
In this study, a novel α-amylase NFAmy13B, from GH13_5 subfamily (according to the Carbohydrate-Active enZYmes Database, CAZy) was successfully heterologous expressed by Escherichia coli from Chinese Nong-flavor (NF) Daqu. It exhibited high stability ranging from pH 5.5 to 12.5, and higher specific activity, compared to other GH13_5 fungal α-amylases. Moreover, NFAmy13B did not show activity loss and retained 96% residual activity after pre-incubation at pH 11 for 21 h and pH 12 for 10 h, respectively. Additionally, 1.25 mM Ca2+ significantly improved its thermostability. NFAmy13B showed a synergistic effect on degrading wheat starch with NFAmy13A (GH13_1), another α-amylase from Daqu. Both enzymes could cleave maltotetraose and maltopentaose in same degradation pattern, and only NFAmy13A could efficiently degrade maltotriose. Moreover, NFAmy13B showed higher catalytic efficiency on long-chain starch, while NFAmy13A had higher catalytic efficiency on short-chain maltooligosaccharides. Their different catalytic efficiencies on starch and maltooligosaccharides may be caused by their discrepant substrate-binding region. Conclusions This study mined a novel GH13_5 fungal α-amylase (NFAmy13B) with outstanding alkali resistance from Nong-flavor (NF) Daqu. Furthermore, its synergistic effect with NFAmy13A (GH13_1) on hydrolyzing wheat starch was confirmed, and their possible contribution in NF Daqu was also speculated. Thus, we not only provide a candidate α-amylase for industry, but also a useful strategy for further studying the interactions in the complex enzyme system of Daqu. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01571-w.
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Affiliation(s)
- Lanchai Chen
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041, Sichuan, People's Republic of China.,Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu, 610065, People's Republic of China
| | - Zhuolin Yi
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yang Fang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yanling Jin
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041, Sichuan, People's Republic of China
| | - Kaize He
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yao Xiao
- Analytical and Testing Center, Sichuan University of Science and Engineering, Zigong, 643000, China
| | - Dong Zhao
- Wuliangye Group, Yibin, 644007, China
| | - Huibo Luo
- Liquor Making Bio-Technology and Application of Key Laboratory of Sichuan Province, Bioengineering College, Sichuan University of Science and Engineering, Zigong, 643000, China
| | - Hui He
- Department of Liquor Making Engineering, Moutai College, Renhuai, 564501, China
| | - Qun Sun
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu, 610065, People's Republic of China.
| | - Hai Zhao
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, 610041, Sichuan, People's Republic of China.
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Silambarasan S, Logeswari P, Sivaramakrishnan R, Pugazhendhi A, Kamaraj B, Ruiz A, Ramadoss G, Cornejo P. Polyhydroxybutyrate production from ultrasound-aided alkaline pretreated finger millet straw using Bacillus megaterium strain CAM12. BIORESOURCE TECHNOLOGY 2021; 325:124632. [PMID: 33485084 DOI: 10.1016/j.biortech.2020.124632] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 06/12/2023]
Abstract
In this study, finger millet straw (FMS) was utilized for the production of Polyhydroxybutyrate (PHB) by Bacillus megaterium strain CAM12. Ultrasound-assisted alkaline (NaOH) pretreatment of FMS under optimized conditions followed by enzymatic saccharification resulted in the maximum delignification (72%), hydrolysis yield (84%), glucose yield (86%) and xylose yield (61%). The effects of different pH, temperature, incubation period, inoculum concentration, agitation speed and FMS enzymatic hydrolysates concentration were investigated to improve the PHB production. Under optimized conditions, strain CAM12 used the FMS hydrolysates as the sole carbon source for their growth and produced 8.31 g L-1 of PHB. The extracted polymer on Fourier transform infrared (FTIR), X-ray diffraction (XRD) and Nuclear magnetic resonance (NMR) analyses were confirmed to be PHB. These results suggest the potential of combined ultrasound and alkaline pretreated FMS hydrolysates as a promising feedstock for PHB production.
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Affiliation(s)
- Sivagnanam Silambarasan
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile
| | - Peter Logeswari
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile
| | - Ramachandran Sivaramakrishnan
- Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | | | - Balu Kamaraj
- Department of Neuroscience Technology, College of Applied Medical Science in Jubail, Imam Abdulrahman Bin Faisal University, Jubail, Saudi Arabia
| | - Antonieta Ruiz
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile; Scientific and Technological Bioresource Nucleus, BIOREN-UFRO, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile
| | - Govindarajan Ramadoss
- School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur 613401, India
| | - Pablo Cornejo
- Centro de Investigación en Micorrizas y Sustentabilidad Agroambiental, CIMYSA, Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile; Scientific and Technological Bioresource Nucleus, BIOREN-UFRO, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile.
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12
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Ye SQ, Zou Y, Zheng QW, Liu YL, Li RR, Lin JF, Guo LQ. TMT-MS/MS proteomic analysis of the carbohydrate-active enzymes in the fruiting body of Pleurotus tuoliensis during storage. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:1879-1891. [PMID: 32894778 DOI: 10.1002/jsfa.10803] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 08/21/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The fruiting body of Pleurotus tuoliensis deteriorates rapidly after harvest, causing a decline in its commercial value and a great reduction in its shelf life. According to the present research, carbohydrate-active enzymes (CAZymes) may cause the softening, liquefaction and autolysis of mature mushrooms after harvest. To further understand the in vivo molecular mechanism of CAZymes affecting the postharvest quality of P. tuoliensis fruiting bodies, a tandem mass tags labelling combined liquid chromatography-tandem mass spectrometry (TMT-MS/MS) proteomic analysis was performed on P. tuoliensis fruiting bodies during storage at 25 °C. RESULTS A total of 4737 proteins were identified, which had at least one unique peptide and had a confidence level above 95%. Consequently, 1307 differentially expressed proteins (DEPs) were recruited using the criteria of abundance fold change (FC) >1.5 or < 0.67 and P < 0.05. The identified proteins were annotated by dbCAN2, a meta server for automated CAZymes annotation. Subsequently, 222 CAZymes were obtained. Several CAZymes participating in the cell wall degradation process, including β-glucosidase, glucan 1,3-β-glucosidase, endo-1,3(4)-β-glucanase and chitinases, were significantly upregulated during storage. The protein expression level of CAZymes, such as xylanase, amylase and glucoamylase, were upregulated significantly, which may participate in the P. tuoliensis polysaccharide degradation. CONCLUSIONS The identified CAZymes degraded the polysaccharides and lignin, destroying the cell wall structure, preventing cell wall remodeling, causing a loss of nutrients and the browning phenomenon, accelerating the deterioration of P. tuoliensis fruiting body. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Si-Qiang Ye
- College of Food Science and Institute of Food Biotechnology, South China Agricultural University, Guangzhou, 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, 510640, China
| | - Yuan Zou
- College of Food Science and Institute of Food Biotechnology, South China Agricultural University, Guangzhou, 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, 510640, China
| | - Qian-Wang Zheng
- College of Food Science and Institute of Food Biotechnology, South China Agricultural University, Guangzhou, 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, 510640, China
| | - Ying-Li Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, 100048, China
| | - Rui-Rong Li
- College of Food Science and Institute of Food Biotechnology, South China Agricultural University, Guangzhou, 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, 510640, China
| | - Jun-Fang Lin
- College of Food Science and Institute of Food Biotechnology, South China Agricultural University, Guangzhou, 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, 510640, China
| | - Li-Qiong Guo
- College of Food Science and Institute of Food Biotechnology, South China Agricultural University, Guangzhou, 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou, 510640, China
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13
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Extraction and characterization of xylan from sugarcane tops as a potential commercial substrate. J Biosci Bioeng 2021; 131:647-654. [PMID: 33676868 DOI: 10.1016/j.jbiosc.2021.01.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 01/17/2023]
Abstract
Xylan is the major hemicellulose present in sugarcane stem secondary cell walls. Xylan is composed of xylose backbone with a high degree of substitutions, which affects its properties. In the present study, the xylan from sugarcane tops (SCT) was extracted and characterized. Compositional analysis of xylan extracted from SCT (SCTx) displayed the presence of 74% of d-xylose residues, 16% of d-glucuronic acid residues and 10% of l-arabinose. High performance size exclusion chromatographic analysis of SCTx displayed a single peak corresponding to a molecular mass of ∼57 kDa. The Fourier transform infrared spectroscopic analysis of SCTx displayed the peaks corresponding to those obtained from commercial xylan. FESEM analysis of SCTx showed the granular and porous surface structure. Differential thermogravimetric analysis (DTG) of SCTx displayed two thermal degradation temperatures (Td) of 228°C, due to breakdown of the side chains of glucuronic acid and arabinose and 275°C, due to breakdown of xylan back bone. The presence of arabinose and glucuronic acid as a side chains was confirmed by the DTG and thermogravimetric analysis. The CHNS analysis of SCTx showed the presence of only carbon and hydrogen supporting its purity. The recombinant xylanase (CtXyn11A) from Clostridium thermocellum displayed a specific activity of 1394 ± 51 U/mg with SCTx, which was higher than those with commercial xylans. The thin layer chromatography and electrospray ionization mass spectroscopy analyses of CtXyn11A hydrolysed SCTx contained a series of linear xylo-oligosaccharides ranging from degree of polymerization 2-6 and no substituted xylo-oligosaccharides because of the endolytic activity of enzyme. The extracted xylan from SCT can be used as an alternative commercial substrate and for oligo-saccharide production.
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14
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Li Q, Jiang Y, Tong X, Zhao L, Pei J. Co-production of Xylooligosaccharides and Xylose From Poplar Sawdust by Recombinant Endo-1,4-β-Xylanase and β-Xylosidase Mixture Hydrolysis. Front Bioeng Biotechnol 2021; 8:637397. [PMID: 33598452 PMCID: PMC7882696 DOI: 10.3389/fbioe.2020.637397] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 12/21/2020] [Indexed: 11/29/2022] Open
Abstract
As is well-known, endo-1,4-β-xylanase and β-xylosidase are the rate-limiting enzymes in the degradation of xylan (the major hemicellulosic component), main functions of which are cleavaging xylan to release xylooligosaccharides (XOS) and xylose that these two compounds have important application value in fuel, food, and other industries. This study focuses on enzymatic hydrolysis of poplar sawdust xylan for production of XOS and xylose by a GH11 endo-1,4-β-xylanase MxynB-8 and a GH39 β-xylosidase Xln-DT. MxynB-8 showed excellent ability to hydrolyze hemicellulose of broadleaf plants, such as poplar. Under optimized conditions (50°C, pH 6.0, dosage of 500 U/g, substrate concentration of 2 mg/mL), the final XOS yield was 85.5%, and the content of XOS2−3 reached 93.9% after 18 h. The enzymatic efficiency by MxynB-8 based on the poplar sawdust xylan in the raw material was 30.5%. Xln-DT showed excellent xylose/glucose/arabinose tolerance, which is applied as a candidate to apply in degradation of hemicellulose. In addition, the process and enzymatic mode of poplar sawdust xylan with MxynB-8 and Xln-DT were investigated. The results showed that the enzymatic hydrolysis yield of poplar sawdust xylan was improved by adding Xln-DT, and a xylose-rich hydrolysate could be obtained at high purity, with the xylose yield of 89.9%. The enzymatic hydrolysis yield was higher (32.2%) by using MxynB-8 and Xln-DT together. This study provides a deep understanding of double-enzyme synergetic enzymolysis of wood polysaccharides to valuable products.
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Affiliation(s)
- Qi Li
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Products, Nanjing Forestry University, Nanjing, China.,College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
| | - Yunpeng Jiang
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
| | - Xinyi Tong
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
| | - Linguo Zhao
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, China.,Co-innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jianjun Pei
- Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Products, Nanjing Forestry University, Nanjing, China.,College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
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15
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Thakur A, Sharma K, Jamaldheen SB, Goyal A. Molecular Characterization, Regioselective and Synergistic Action of First Recombinant Type III α-L-arabinofuranosidase of Family 43 Glycoside Hydrolase (PsGH43_12) from Pseudopedobacter saltans. Mol Biotechnol 2020; 62:443-455. [DOI: 10.1007/s12033-020-00263-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2020] [Indexed: 01/26/2023]
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16
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Sharma K, Khaire KC, Thakur A, Moholkar VS, Goyal A. Acacia Xylan as a Substitute for Commercially Available Xylan and Its Application in the Production of Xylooligosaccharides. ACS OMEGA 2020; 5:13729-13738. [PMID: 32566838 PMCID: PMC7301597 DOI: 10.1021/acsomega.0c00896] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/19/2020] [Indexed: 05/08/2023]
Abstract
Over the past two decades, birchwood and beechwood xylans have been used as a popular substrate for the characterization of xylanases. Recently, major companies have discontinued their commercial production. Therefore, there is a need to find an alternative to these substrates. Xylan extraction from Acacia sawdust resulted in 23.5% (w/w) yield. The extracted xylan is composed of xylose and glucuronic acid residues in a molar ratio of 6:1 with a molecular mass of ∼70 kDa. The specific optical rotation analysis of extracted xylan displayed that it is composed of the d-form of xylose and glucuronic acid monomeric sugars. The nuclear magnetic resonance analysis of extracted xylan revealed that the xylan backbone is substituted with 4-O-methyl glucuronic acid at the O2 position. Fourier transform infrared analysis confirmed the absence of lignin contamination in the extracted xylan. Xylanase from Clostridium thermocellum displayed the enzyme activity of 1761 U/mg against extracted xylan, and the corresponding activity against beechwood xylan was 1556 U/mg, which confirmed that the extracted xylan could be used as an alternative substrate for the characterization of xylanases.
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Affiliation(s)
- Kedar Sharma
- Carbohydrate
Enzyme Biotechnology Laboratory, Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Kaustubh Chandrakant Khaire
- Carbohydrate
Enzyme Biotechnology Laboratory, Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Abhijeet Thakur
- Carbohydrate
Enzyme Biotechnology Laboratory, Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Vijayanand Suryakant Moholkar
- Carbohydrate
Enzyme Biotechnology Laboratory, Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Arun Goyal
- Carbohydrate
Enzyme Biotechnology Laboratory, Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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Malgas S, Mafa MS, Mkabayi L, Pletschke BI. A mini review of xylanolytic enzymes with regards to their synergistic interactions during hetero-xylan degradation. World J Microbiol Biotechnol 2019; 35:187. [PMID: 31728656 DOI: 10.1007/s11274-019-2765-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/06/2019] [Indexed: 10/25/2022]
Abstract
This review examines the recent models describing the mode of action of various xylanolytic enzymes and how these enzymes can be applied (sequentially or simultaneously) with their distinctive roles in mind to achieve efficient xylan degradation. With respect to homeosynergy, synergism appears to be as a result of β-xylanase and/or oligosaccharide reducing-end β-xylanase liberating xylo-oligomers (XOS) that are preferred substrates of the processive β-xylosidase. With regards to hetero-synergism, two cross relationships appear to exist and seem to be the reason for synergism between the enzymes during xylan degradation. These cross relations are the debranching enzymes such as α-glucuronidase or side-chain cleaving enzymes such as carbohydrate esterases (CE) removing decorations that would have hindered back-bone-cleaving enzymes, while backbone-cleaving-enzymes liberate XOS that are preferred substrates of the debranching and side-chain-cleaving enzymes. This interaction is demonstrated by high yields in co-production of xylan substituents such as arabinose, glucuronic acid and ferulic acid, and XOS. Finally, lytic polysaccharide monooxygenases (LPMO) have also been implicated in boosting whole lignocellulosic biomass or insoluble xylan degradation by glycoside hydrolases (GH) by possibly disrupting entangled xylan residues. Since it has been observed that the same enzyme (same Enzyme Commission, EC, classification) from different GH or CE and/or AA families can display different synergistic interactions with other enzymes due to different substrate specificities and properties, in this review, we propose an approach of enzyme selection (and mode of application thereof) during xylan degradation, as this can improve the economic viability of the degradation of xylan for producing precursors of value added products.
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Affiliation(s)
- Samkelo Malgas
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa
| | - Mpho S Mafa
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa.,Protein Structure-Function Research Unit (PSFRU), School of Molecular and Cell Biology, Wits University, Johannesburg, Gauteng, 2000, South Africa
| | - Lithalethu Mkabayi
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa
| | - Brett I Pletschke
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa.
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