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Vacilotto MM, de Araujo Montalvão L, Pellegrini VDOA, Liberato MV, de Araujo EA, Polikarpov I. Two-domain GH30 xylanase from human gut microbiota as a tool for enzymatic production of xylooligosaccharides: Crystallographic structure and a synergy with GH11 xylosidase. Carbohydr Polym 2024; 337:122141. [PMID: 38710568 DOI: 10.1016/j.carbpol.2024.122141] [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: 12/24/2023] [Revised: 03/21/2024] [Accepted: 04/07/2024] [Indexed: 05/08/2024]
Abstract
Production of value-added compounds and sustainable materials from agro-industrial residues is essential for better waste management and building of circular economy. This includes valorization of hemicellulosic fraction of plant biomass, the second most abundant biopolymer from plant cell walls, aiming to produce prebiotic oligosaccharides, widely explored in food and feed industries. In this work, we conducted biochemical and biophysical characterization of a prokaryotic two-domain R. champanellensis xylanase from glycoside hydrolase (GH) family 30 (RcXyn30A), and evaluated its applicability for XOS production from glucuronoxylan in combination with two endo-xylanases from GH10 and GH11 families and a GH11 xylobiohydrolase. RcXyn30A liberates mainly long monoglucuronylated xylooligosaccharides and is inefficient in cleaving unbranched oligosaccharides. Crystallographic structure of RcXyn30A catalytic domain was solved and refined to 1.37 Å resolution. Structural analysis of the catalytic domain releveled that its high affinity for glucuronic acid substituted xylan is due to the coordination of the substrate decoration by several hydrogen bonds and ionic interactions in the subsite -2. Furthermore, the protein has a larger β5-α5 loop as compared to other GH30 xylanases, which might be crucial for creating an additional aglycone subsite (+3) of the catalytic site. Finally, RcXyn30A activity is synergic to that of GH11 xylobiohydrolase.
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Affiliation(s)
- Milena Moreira Vacilotto
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Lucas de Araujo Montalvão
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | | | - Marcelo Vizona Liberato
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Evandro Ares de Araujo
- Centro Nacional de Pesquisa em Energia e Materiais, Giuseppe Máximo Scolfaro 10000, 13083-100 Campinas, SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil.
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2
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Østby H, Várnai A. Hemicellulolytic enzymes in lignocellulose processing. Essays Biochem 2023; 67:533-550. [PMID: 37068264 PMCID: PMC10160854 DOI: 10.1042/ebc20220154] [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: 12/15/2022] [Revised: 01/25/2023] [Accepted: 01/30/2023] [Indexed: 04/19/2023]
Abstract
Lignocellulosic biomass is the most abundant source of carbon-based material on a global basis, serving as a raw material for cellulosic fibers, hemicellulosic polymers, platform sugars, and lignin resins or monomers. In nature, the various components of lignocellulose (primarily cellulose, hemicellulose, and lignin) are decomposed by saprophytic fungi and bacteria utilizing specialized enzymes. Enzymes are specific catalysts and can, in many cases, be produced on-site at lignocellulose biorefineries. In addition to reducing the use of often less environmentally friendly chemical processes, the application of such enzymes in lignocellulose processing to obtain a range of specialty products can maximize the use of the feedstock and valorize many of the traditionally underutilized components of lignocellulose, while increasing the economic viability of the biorefinery. While cellulose has a rich history of use in the pulp and paper industries, the hemicellulosic fraction of lignocellulose remains relatively underutilized in modern biorefineries, among other reasons due to the heterogeneous chemical structure of hemicellulose polysaccharides, the composition of which varies significantly according to the feedstock and the choice of pretreatment method and extraction solvent. This paper reviews the potential of hemicellulose in lignocellulose processing with focus on what can be achieved using enzymatic means. In particular, we discuss the various enzyme activities required for complete depolymerization of the primary hemicellulose types found in plant cell walls and for the upgrading of hemicellulosic polymers, oligosaccharides, and pentose sugars derived from hemicellulose depolymerization into a broad spectrum of value-added products.
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Affiliation(s)
- Heidi Østby
- Norwegian University of Life Sciences (NMBU), Faculty of Chemistry, Biotechnology and Food Science, P.O. Box 5003, N-1432 Aas, Norway
| | - Anikó Várnai
- Norwegian University of Life Sciences (NMBU), Faculty of Chemistry, Biotechnology and Food Science, P.O. Box 5003, N-1432 Aas, Norway
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3
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Fuso A, Dejonghe W, Cauwenberghs L, Rosso G, Rosso F, Manera I, Caligiani A. DPPH radical scavenging activity of xylo-oligosaccharides mixtures of controlled composition: A step forward in understanding structure–activity relationship. J Funct Foods 2023. [DOI: 10.1016/j.jff.2023.105417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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4
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Capetti CCDM, Pellegrini VOA, Espirito Santo MC, Cortez AA, Falvo M, Curvelo AADS, Campos E, Filgueiras JG, Guimaraes FEG, de Azevedo ER, Polikarpov I. Enzymatic production of xylooligosaccharides from corn cobs: Assessment of two different pretreatment strategies. Carbohydr Polym 2023; 299:120174. [PMID: 36876789 DOI: 10.1016/j.carbpol.2022.120174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 10/14/2022]
Abstract
Corn cobs (CCs) are abundant xylan-rich agricultural wastes. Here, we compared CCs XOS yields obtained via two different pretreatment routs, alkali and hydrothermal, using a set of recombinant endo- and exo-acting enzymes from GH10 and GH11 families, which have different restrictions for xylan substitutions. Furthermore, impacts of the pretreatments on chemical composition and physical structure of the CCs samples were evaluated. We demonstrated that alkali pretreatment route rendered 59 mg of XOS per gram of initial biomass, while an overall XOS yield of 115 mg/g was achieved via hydrothermal pretreatment using a combination of GH10 and GH11 enzymes. These results hold a promise of ecologically sustainable enzymatic valorization of CCs via "green" and sustainable XOS production.
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Affiliation(s)
- Caio Cesar de Mello Capetti
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | | | - Melissa Cristina Espirito Santo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Anelyse Abreu Cortez
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Maurício Falvo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Antonio Aprigio da Silva Curvelo
- Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Eleonora Campos
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Los Reseros y N. Repetto, Hurlingham B1686, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Jefferson Gonçalves Filgueiras
- Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, 24020-007, Niterói, RJ, Brazil; Instituto de Física, Universidade Federal do Rio de Janeiro, CP68528, 21941-972, Rio de Janeiro, RJ, Brazil
| | | | - Eduardo Ribeiro de Azevedo
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil.
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2019-2020. MASS SPECTROMETRY REVIEWS 2022:e21806. [PMID: 36468275 DOI: 10.1002/mas.21806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing.
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Affiliation(s)
- David J Harvey
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire, United Kingdom
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Wei H, Liu M, Zhang K, Li J, Ouyang X. Heterologous expression of family GH11 Aspergillus niger xylanase B (AnXylB11) in Pichia pastoris and competitive inhibition by riceXIP: An experimental and simulation study. Colloids Surf B Biointerfaces 2022; 220:112907. [DOI: 10.1016/j.colsurfb.2022.112907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/03/2022] [Accepted: 10/07/2022] [Indexed: 11/27/2022]
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Silva VTF, Ruschoni UCM, Ferraz A, Milagres AMF. Xylan, Xylooligosaccharides, and Aromatic Structures With Antioxidant Activity Released by Xylanase Treatment of Alkaline-Sulfite–Pretreated Sugarcane Bagasse. Front Bioeng Biotechnol 2022; 10:940712. [PMID: 35898646 PMCID: PMC9313595 DOI: 10.3389/fbioe.2022.940712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/09/2022] [Indexed: 11/29/2022] Open
Abstract
Xylanase enzymes are useful to fractionate plant biomass, producing xylan, xylooligosaccharides (XOS), and antioxidant-derived XOS. In a biorefinery, pretreated biomass can be digested with xylanase prior to cellulose saccharification, enhancing the product portfolio in the process. With this vision, this study highlighted a wide range of new products attainable from alkaline-sulfite–pretreated sugarcane bagasse by treatments with endo-xylanase under controlled conditions. The developed process provided a crude extract corresponding to 29.7% (w/w) of pretreated sugarcane bagasse. The crude extract included a relatively polymeric glucuronoarabinoxylan fraction, DP2-DP6 xylooligosaccharides, and aromatic compounds. The enzymatically produced extract was fractionated with increasing ethanol concentrations [up to 90% (v/v)], providing precipitation of varied polymeric xylan fractions (48% (w/w) of the crude extract) with average molar masses ranging from 28 kDa to 3.6 kDa. The fraction soluble in 90% ethanol was subjected to adsorption on 4% (w/v) activated charcoal and eluted with an ethanol gradient from 10% to 70% (v/v), thus providing xylooligosaccharides and aromatic fractions. Most of the xylooligosaccharides (74% of the eluted sugars) were washed out in 10%–30% ethanol. DP2 and DP3 structures predominated in the 10% ethanol fraction, while DP5 structures were significantly enriched in the 30% ethanol fraction. Higher ethanol concentrations desorbed xylooligosaccharides associated with higher amounts of aromatic compounds. Total aromatics, phenolic structures, and p-hydroxycinnamates predominated in the fractions desorbed with 60% and 70% ethanol. The antioxidant activity of produced fractions correlated with their phenolic contents. Compiled results indicate that a wide variety of products can be prepared from pretreated biomass using xylanase-aided extraction procedures. Recovered fractions presented different features and specific application prospects. Beyond polymeric xylan with low lignin contamination, xylooligosaccharides or even lignin-carbohydrate complexes with antioxidant activity can be included in the biorefinery portfolio based on the currently developed fractionation studies.
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8
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Vacilotto MM, Pellegrini VOA, Sepulchro AGV, Capetti CCDM, Curvelo AAS, Marcondes WF, Arantes V, Polikarpov I. Paludibacter propionicigenes GH10 xylanase as a tool for enzymatic xylooligosaccharides production from heteroxylans. Carbohydr Polym 2022; 275:118684. [PMID: 34742414 DOI: 10.1016/j.carbpol.2021.118684] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/30/2021] [Accepted: 09/16/2021] [Indexed: 12/17/2022]
Abstract
Bioconversion of lignocellulosic biomass into value-added products relies on polysaccharides depolymerization by carbohydrate active enzymes. This work reports biochemical characterization of Paludibacter propionicigenes xylanase from GH10 (PpXyn10A) and its application for enzymatic xylooligosaccharides (XOS) production from commercial heteroxylans and liquor of hydrothermally pretreated corn cobs (PCC). PpXyn10A is tolerant to ethanol and NaCl, and releases xylobiose (X2) and xylotriose (X3) as the main hydrolytic products. The conversion rate of complex substrates into short XOS was approximately 30% for glucuronoxylan and 8.8% for rye arabinoxylan, after only 4 h; while for PCC, PpXyn10A greatly increased unbranched XOS yields. B. adolescentis fermentation with XOS from beechwood glucuronoxylan produced mainly acetic and lactic acids. Structural analysis shows that while the glycone region of PpXyn10A active site is well preserved, the aglycone region has aromatic interactions in the +2 subsite that may explain why PpXyn10A does not release xylose.
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Affiliation(s)
- Milena Moreira Vacilotto
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Vanessa O Arnoldi Pellegrini
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Ana Gabriela Veiga Sepulchro
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Caio C de Mello Capetti
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Antonio Aprigio S Curvelo
- Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil
| | - Wilian Fioreli Marcondes
- Biocatalysis and Bioproducts Laboratory, Department of Biotechnology, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP, Brazil
| | - Valdeir Arantes
- Biocatalysis and Bioproducts Laboratory, Department of Biotechnology, Escola de Engenharia de Lorena, Universidade de São Paulo, Lorena, SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos, SP, Brazil.
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9
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Glucuronosylated and linear xylooligosaccharides from Quinoa stalks xylan as potential prebiotic source for growth of Bifidobacterium adolescentis and Weissella cibaria. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.112348] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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10
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Chen Y, Xie Y, Ajuwon KM, Zhong R, Li T, Chen L, Zhang H, Beckers Y, Everaert N. Xylo-Oligosaccharides, Preparation and Application to Human and Animal Health: A Review. Front Nutr 2021; 8:731930. [PMID: 34568407 PMCID: PMC8458953 DOI: 10.3389/fnut.2021.731930] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/16/2021] [Indexed: 01/19/2023] Open
Abstract
Xylo-oligosaccharides (XOS) are considered as functional oligosaccharides and have great prebiotic potential. XOS are the degraded products of xylan prepared via chemical, physical or enzymatic degradation. They are mainly composed of xylose units linked by β-1, 4 bonds. XOS not only exhibit some specific physicochemical properties such as excellent water solubility and high temperature resistance, but also have a variety of functional biological activities including anti-inflammation, antioxidative, antitumor, antimicrobial properties and so on. Numerous studies have revealed in the recent decades that XOS can be applied to many food and feed products and exert their nutritional benefits. XOS have also been demonstrated to reduce the occurrence of human health-related diseases, improve the growth and resistance to diseases of animals. These effects open a new perspective on XOS potential applications for human consumption and animal production. Herein, this review aims to provide a general overview of preparation methods for XOS, and will also discuss the current application of XOS to human and animal health field.
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Affiliation(s)
- Yuxia Chen
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.,Precision Livestock and Nutrition Unit, Gembloux Agro-Bio Tech, TERRA Teaching and Research Centre, Liège University, Gembloux, Belgium
| | - Yining Xie
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Kolapo M Ajuwon
- Departments of Animal Sciences, Purdue University, West Lafayette, IN, United States
| | - Ruqing Zhong
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tao Li
- Hunan United Bio-Technology Co., Changsha, China
| | - Liang Chen
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hongfu Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yves Beckers
- Precision Livestock and Nutrition Unit, Gembloux Agro-Bio Tech, TERRA Teaching and Research Centre, Liège University, Gembloux, Belgium
| | - Nadia Everaert
- Precision Livestock and Nutrition Unit, Gembloux Agro-Bio Tech, TERRA Teaching and Research Centre, Liège University, Gembloux, Belgium
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Endo-xylanases from Cohnella sp. AR92 aimed at xylan and arabinoxylan conversion into value-added products. Appl Microbiol Biotechnol 2021; 105:6759-6778. [PMID: 34458936 DOI: 10.1007/s00253-021-11495-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 06/29/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
The genus Cohnella belongs to a group of Gram-positive endospore-forming bacteria within the Paenibacillaceae family. Although most species were described as xylanolytic bacteria, the literature still lacks some key information regarding their repertoire of xylan-degrading enzymes. The whole genome sequence of an isolated xylan-degrading bacterium Cohnella sp. strain AR92 was found to contain five genes encoding putative endo-1,4-β-xylanases, of which four were cloned, expressed, and characterized to better understand the contribution of the individual endo-xylanases to the overall xylanolytic properties of strain AR92. Three of the enzymes, CoXyn10A, CoXyn10C, and CoXyn11A, were shown to be effective at hydrolyzing xylans-derived from agro-industrial, producing oligosaccharides with substrate conversion values of 32.5%, 24.7%, and 10.6%, respectively, using sugarcane bagasse glucuronoarabinoxylan and of 29.9%, 19.1%, and 8.0%, respectively, using wheat bran-derived arabinoxylan. The main reaction products from GH10 enzymes were xylobiose and xylotriose, whereas CoXyn11A produced mostly xylooligosaccharides (XOS) with 2 to 5 units of xylose, often substituted, resulting in potentially prebiotic arabinoxylooligosaccharides (AXOS). The endo-xylanases assay displayed operational features (temperature optima from 49.9 to 50.4 °C and pH optima from 6.01 to 6.31) fitting simultaneous xylan utilization. Homology modeling confirmed the typical folds of the GH10 and GH11 enzymes, substrate docking studies allowed the prediction of subsites (- 2 to + 1 in GH10 and - 3 to + 1 in GH11) and identification of residues involved in ligand interactions, supporting the experimental data. Overall, the Cohnella sp. AR92 endo-xylanases presented significant potential for enzymatic conversion of agro-industrial by-products into high-value products.Key points• Cohnella sp. AR92 genome encoded five potential endo-xylanases.• Cohnella sp. AR92 enzymes produced xylooligosaccharides from xylan, with high yields.• GH10 enzymes from Cohnella sp. AR92 are responsible for the production of X2 and X3 oligosaccharides.• GH11 from Cohnella sp. AR92 contributes to the overall xylan degradation by producing substituted oligosaccharides.
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12
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Xylanases of glycoside hydrolase family 30 - An overview. Biotechnol Adv 2021; 47:107704. [PMID: 33548454 DOI: 10.1016/j.biotechadv.2021.107704] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 01/23/2021] [Accepted: 01/25/2021] [Indexed: 12/22/2022]
Abstract
Xylan is the most abundant hemicellulose in nature and as such it is a huge source of renewable carbon. Its bioconversion requires a battery of xylanolytic enzymes. Of them the most important are the endo-β-1,4-xylanases which depolymerize the polysaccharide into smaller fragments. Most of the xylanases are members of glycoside hydrolase (GH) families 10 and 11, although they are classified in some other GH families. The relatively new xylanases of GH30 are of special interest. Initially, they appeared to be specific glucuronoxylanases, however, other specificities were found later among prokaryotic and in particular eukaryotic enzymes. This review gives an overview of the substrate and product specificities observed for the GH30 xylanases characterized to date. An emphasis is given to the structure-activity relationship in order to explain how minor differences in catalytic centre and its vicinity can alter catalytic properties from the endoxylanase into the reducing end xylose releasing exoxylanase or into the non-reducing end xylobiohydrolase. Biotechnological potential of the GH30 xylanases is also considered.
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13
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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: 14] [Impact Index Per Article: 3.5] [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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14
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Jiménez‐Ortega E, Valenzuela S, Ramírez‐Escudero M, Pastor FJ, Sanz‐Aparicio J. Structural analysis of the reducing‐end xylose‐releasing exo‐oligoxylanase Rex8A from
Paenibacillus barcinonensis
BP‐23 deciphers its molecular specificity. FEBS J 2020; 287:5362-5374. [DOI: 10.1111/febs.15332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/27/2020] [Accepted: 04/09/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Elena Jiménez‐Ortega
- Macromolecular Crystallography and Structural Biology Department Institute of Physical‐Chemistry ‘Rocasolano’ CSIC Madrid Spain
| | - Susana Valenzuela
- Department of Microbiology Faculty of Biology University of Barcelona Spain
- Institute of Nanoscience and Nanotechnology (IN2UB) University of Barcelona Spain
| | - Mercedes Ramírez‐Escudero
- Macromolecular Crystallography and Structural Biology Department Institute of Physical‐Chemistry ‘Rocasolano’ CSIC Madrid Spain
| | - Francisco Javier Pastor
- Department of Microbiology Faculty of Biology University of Barcelona Spain
- Institute of Nanoscience and Nanotechnology (IN2UB) University of Barcelona Spain
| | - Julia Sanz‐Aparicio
- Macromolecular Crystallography and Structural Biology Department Institute of Physical‐Chemistry ‘Rocasolano’ CSIC Madrid Spain
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