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Sousa J, Santos-Pereira C, Gomes JS, Costa ÂMA, Santos AO, Franco-Duarte R, Linhares JMM, Sousa SF, Silvério SC, Rodrigues LR. Heterologous expression and structure prediction of a xylanase identified from a compost metagenomic library. Appl Microbiol Biotechnol 2024; 108:329. [PMID: 38727750 PMCID: PMC11087322 DOI: 10.1007/s00253-024-13169-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/22/2024] [Accepted: 05/02/2024] [Indexed: 05/13/2024]
Abstract
Xylanases are key biocatalysts in the degradation of the β-1,4-glycosidic linkages in the xylan backbone of hemicellulose. These enzymes are potentially applied in a wide range of bioprocessing industries under harsh conditions. Metagenomics has emerged as powerful tools for the bioprospection and discovery of interesting bioactive molecules from extreme ecosystems with unique features, such as high temperatures. In this study, an innovative combination of function-driven screening of a compost metagenomic library and automatic extraction of halo areas with in-house MATLAB functions resulted in the identification of a promising clone with xylanase activity (LP4). The LP4 clone proved to be an effective xylanase producer under submerged fermentation conditions. Sequence and phylogenetic analyses revealed that the xylanase, Xyl4, corresponded to an endo-1,4-β-xylanase belonging to glycosyl hydrolase family 10 (GH10). When xyl4 was expressed in Escherichia coli BL21(DE3), the enzyme activity increased about 2-fold compared to the LP4 clone. To get insight on the interaction of the enzyme with the substrate and establish possible strategies to improve its activity, the structure of Xyl4 was predicted, refined, and docked with xylohexaose. Our data unveiled, for the first time, the relevance of the amino acids Glu133 and Glu238 for catalysis, and a close inspection of the catalytic site suggested that the replacement of Phe316 by a bulkier Trp may improve Xyl4 activity. Our current findings contribute to enhancing the catalytic performance of Xyl4 towards industrial applications. KEY POINTS: • A GH10 endo-1,4-β-xylanase (Xyl4) was isolated from a compost metagenomic library • MATLAB's in-house functions were developed to identify the xylanase-producing clones • Computational analysis showed that Glu133 and Glu238 are crucial residues for catalysis.
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Affiliation(s)
- Joana Sousa
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Cátia Santos-Pereira
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Joana S Gomes
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Ângela M A Costa
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Andréia O Santos
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Ricardo Franco-Duarte
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
- IB-S - Institute of Science and Innovation for Bio-Sustainability, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - João M M Linhares
- Physics Center of Minho and Porto Universities (CF-UM-UP), Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Sérgio F Sousa
- LAQV/REQUIMTE BioSIM - Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal
| | - Sara C Silvério
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal.
| | - Lígia R Rodrigues
- CEB - Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
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2
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Tang L, Lei X, Ouyang K, Wang L, Qiu Q, Li Y, Zang Y, Liu C, Zhao X. A Glycosyl Hydrolase 30 Family Xylanase from the Rumen Metagenome and Its Effects on In Vitro Ruminal Fermentation of Wheat Straw. Animals (Basel) 2023; 14:118. [PMID: 38200851 PMCID: PMC10778502 DOI: 10.3390/ani14010118] [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: 11/07/2023] [Revised: 12/23/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
The challenge of wheat straw as a ruminant feed is its low ruminal digestibility. This study investigated the impact of a xylanase called RuXyn, derived from the rumen metagenome of beef cattle, on the in vitro ruminal fermentation of wheat straw. RuXyn encoded 505 amino acids and was categorized within subfamily 8 of the glycosyl hydrolase 30 family. RuXyn was heterologously expressed in Escherichia coli and displayed its highest level of activity at pH 6.0 and 40 °C. RuXyn primarily hydrolyzed xylan, while it did not show any noticeable activity towards other substrates, including carboxymethylcellulose and Avicel. At concentrations of 5 mM, Mn2+ and dithiothreitol significantly enhanced RuXyn's activity by 73% and 20%, respectively. RuXyn's activity was almost or completely inactivated in the presence of Cu2+, even at low concentrations. The main hydrolysis products of corncob xylan by RuXyn were xylopentose, xylotriose, and xylotetraose. RuXyn hydrolyzed wheat straw and rice straw more effectively than it did other agricultural by-products. A remarkable synergistic effect was observed between RuXyn and a cellulase cocktail on wheat straw hydrolysis. Supplementation with RuXyn increased dry matter digestibility; acetate, propionate, valerate, and total volatile fatty acid yields; NH3-N concentration, and total bacterial number during in vitro fermentation of wheat straw relative to the control. RuXyn's inactivity at 60 °C and 70 °C was remedied by mutating proline 151 to phenylalanine and aspartic acid 204 to leucine, boosting activity to 20.3% and 21.8% of the maximum activity at the respective temperatures. As an exogenous enzyme preparation, RuXyn exhibits considerable potential to improve ruminal digestion and the utilization of wheat straw in ruminants. As far as we know, this is the first study on a GH30 xylanase promoting the ruminal fermentation of agricultural straws. The findings demonstrate that the utilization of RuXyn can significantly enhance the ruminal digestibility of wheat straw by approximately 10 percentage points. This outcome signifies the emergence of a novel and highly efficient enzyme preparation that holds promise for the effective utilization of wheat straw, a by-product of crop production, in ruminants.
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Affiliation(s)
- Longzhang Tang
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
| | - Xiaowen Lei
- Ganzhou Animal Husbandry and Fisheries Research Institute, Ganzhou 341000, China;
| | - Kehui Ouyang
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
| | - Lei Wang
- Shandong Institute for Food and Drug Control, Jinan 250101, China;
| | - Qinghua Qiu
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
| | - Yanjiao Li
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
| | - Yitian Zang
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
| | - Chanjuan Liu
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
| | - Xianghui Zhao
- Jiangxi Province Key Laboratory of Animal Nutrition, Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China; (L.T.); (K.O.); (Q.Q.); (Y.L.); (Y.Z.); (C.L.)
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3
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Gharechahi J, Vahidi MF, Sharifi G, Ariaeenejad S, Ding XZ, Han JL, Salekdeh GH. Lignocellulose degradation by rumen bacterial communities: New insights from metagenome analyses. ENVIRONMENTAL RESEARCH 2023; 229:115925. [PMID: 37086884 DOI: 10.1016/j.envres.2023.115925] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/26/2023] [Accepted: 04/15/2023] [Indexed: 05/03/2023]
Abstract
Ruminant animals house a dense and diverse community of microorganisms in their rumen, an enlarged compartment in their stomach, which provides a supportive environment for the storage and microbial fermentation of ingested feeds dominated by plant materials. The rumen microbiota has acquired diverse and functionally overlapped enzymes for the degradation of plant cell wall polysaccharides. In rumen Bacteroidetes, enzymes involved in degradation are clustered into polysaccharide utilization loci to facilitate coordinated expression when target polysaccharides are available. Firmicutes use free enzymes and cellulosomes to degrade the polysaccharides. Fibrobacters either aggregate lignocellulose-degrading enzymes on their cell surface or release them into the extracellular medium in membrane vesicles, a mechanism that has proven extremely effective in the breakdown of recalcitrant cellulose. Based on current metagenomic analyses, rumen Bacteroidetes and Firmicutes are categorized as generalist microbes that can degrade a wide range of polysaccharides, while other members adapted toward specific polysaccharides. Particularly, there is ample evidence that Verrucomicrobia and Spirochaetes have evolved enzyme systems for the breakdown of complex polysaccharides such as xyloglucans, peptidoglycans, and pectin. It is concluded that diversity in degradation mechanisms is required to ensure that every component in feeds is efficiently degraded, which is key to harvesting maximum energy by host animals.
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Affiliation(s)
- Javad Gharechahi
- Human Genetics Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhad Vahidi
- Animal Science Research Department, Qom Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Qom, Iran
| | - Golandam Sharifi
- Department of Basic Sciences, Encyclopedia Research Center, Institute for Humanities and Cultural Studies, Tehran, Iran
| | - Shohreh Ariaeenejad
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education, And Extension Organization, Karaj, Iran
| | - Xue-Zhi Ding
- Key Laboratory of Yak Breeding Engineering, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences (CAAS), Lanzhou, 730050, China
| | - Jian-Lin Han
- Livestock Genetics Program, International Livestock Research, Institute (ILRI), 00100, Nairobi, Kenya; CAAS-ILRI Joint Laboratory on Livestock and Forage Genetic Resources, Institute of Animal Science, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100193, China.
| | - Ghasem Hosseini Salekdeh
- Department of Systems Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education, And Extension Organization, Karaj, Iran; School of Natural Sciences, Macquarie University, North Ryde, NSW, Australia.
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4
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Zhu L, Liu LWC, Li Y, Pan K, Ouyang K, Song X, Xiong X, Qu M, Zhao X. Characteristics of recombinant xylanase from camel rumen metagenome and its effects on wheat bran hydrolysis. Int J Biol Macromol 2022; 220:1309-1317. [PMID: 36027987 DOI: 10.1016/j.ijbiomac.2022.08.146] [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: 04/26/2022] [Revised: 08/08/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022]
Abstract
In the present study, we explored the effects of a novel xylanase from camel rumen metagenome (CrXyn) on wheat bran hydrolysis. CrXyn was heterologously expressed in Escherichia coli and showed maximum activity at 40 °C and pH 7.0. Furthermore, CrXyn exhibited preferential hydrolysis of xylan, but no obvious activity toward other substrates, including carboxymethylcellulose and Avicel. Using wheat straw xylan as a substrate, the Km and Vmax values for CrXyn were 5.98 g/L and 179.9 μmol xylose/min/mg protein, respectively. Mn2+ was a strong accelerator and significantly enhanced CrXyn activity. However, CrXyn activity was inhibited (~50 %) by 1 mM and 5 mM ethylenediaminetetraacetic acid (EDTA) and completely inactivated by 5 mM Cu2+. CrXyn tolerated 5 mM sodium dodecyl sulphate (SDS) and 15 % methanol, ethanol, and dimethyl sulfoxide (DMSO), with >50 % residual activity. CrXyn effectively hydrolyzed wheat bran, with xylobiose and xylotetraose accounting for 79.1 % of total sugars produced. A remarkable synergistic effect was found between CrXyn and protease, leading to an obvious increase in amino acids released from wheat bran compared with the control. CrXyn also enhanced the in vitro hydrolysis of wheat bran. Thus, CrXyn exhibits great potential as a feed additive to improve the utilization of wheat bran in monogastric animal production.
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Affiliation(s)
- Linli Zhu
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Lei Wang Chanjuan Liu
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Yanjiao Li
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Ke Pan
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Kehui Ouyang
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Xiaozhen Song
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Xiaowen Xiong
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Mingren Qu
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Xianghui Zhao
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China.
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5
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Mon ML, Marrero Díaz de Villegas R, Campos E, Soria MA, Talia PM. Characterization of a novel GH10 alkali-thermostable xylanase from a termite microbiome. BIORESOUR BIOPROCESS 2022; 9:84. [PMID: 38647897 PMCID: PMC10992782 DOI: 10.1186/s40643-022-00572-w] [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: 05/25/2022] [Accepted: 08/02/2022] [Indexed: 11/10/2022] Open
Abstract
The aim of the present study was to assess the biochemical and molecular structural characteristics of a novel alkali-thermostable GH10 xylanase (Xyl10B) identified in a termite gut microbiome by a shotgun metagenomic approach. This endoxylanase candidate was amplified, cloned, heterologously expressed in Escherichia coli and purified. The recombinant enzyme was active at a broad range of temperatures (37-60 ºC) and pH values (4-10), with optimal activity at 50 ºC and pH 9. Moreover, its activity remained at more than 80% of its maximum at 50 °C for 8 h. In addition, Xyl10B was found to be stable in the presence of salt and several ions and chemical reagents frequently used in the industry. These characteristics make this enzyme an interesting candidate for pulp and paper bleaching industries, since this process requires enzymes without cellulase activity and resistant to high temperatures and alkaline pH (thermo-alkaliphilic enzymes). The products of xylan hydrolysis by Xyl10B (short xylooligosaccharides, xylose and xylobiose) could be suitable for application as prebiotics and in the production of bioethanol.
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Affiliation(s)
- Maria Laura Mon
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina
| | - Rubén Marrero Díaz de Villegas
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina
| | - Eleonora Campos
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina
| | - Marcelo A Soria
- Facultad de Agronomía, Cátedra de Microbiología Agrícola, Universidad de Buenos Aires, INBA UBA-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Paola M Talia
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Buenos Aires, Argentina.
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6
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Hu D, Zhao X. Characterization of a New Xylanase Found in the Rumen Metagenome and Its Effects on the Hydrolysis of Wheat. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:6493-6502. [PMID: 35583133 DOI: 10.1021/acs.jafc.2c00827] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Wheat is the main ingredient of poultry diet, but its xylan has an adverse impact on poultry production. A novel xylanase from beef cattle rumen metagenome (RuXyn) and its effect on the wheat hydrolysis were investigated in the present study. The RuXyn coded for 377 amino acids and exhibited low identity (<40%) to previously reported proteins. The RuXyn was heterologously expressed in Escherichia coli and showed maximum activity at pH 6.0 and 40 °C. The activity of RuXyn could be increased by 79.8 and 36.0% in the presence of Ca2+ and Tween 20, respectively. The soluble xylan and insoluble xylan in wheat could be effectively degraded by RuXyn and xylooligosaccharides produced accounting for more than 80% of the products. This study demonstrates that RuXyn has substantial potential to improve the application of wheat in poultry production by degrading wheat xylan and the accompanying xylooligosaccharides produced.
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Affiliation(s)
- Die Hu
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
| | - Xianghui Zhao
- Jiangxi Province Key Laboratory of Animal Nutrition/Engineering Research Center of Feed Development, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China
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Liu Z, Wen S, Wu G, Wu H. Heterologous expression and characterization of Anaeromyces robustus xylanase and its use in bread making. Eur Food Res Technol 2022. [DOI: 10.1007/s00217-022-04047-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Verma D, Satyanarayana T. Xylanolytic Extremozymes Retrieved From Environmental Metagenomes: Characteristics, Genetic Engineering, and Applications. Front Microbiol 2020; 11:551109. [PMID: 33042057 PMCID: PMC7527525 DOI: 10.3389/fmicb.2020.551109] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 08/21/2020] [Indexed: 01/29/2023] Open
Abstract
Xylanolytic enzymes have extensive applications in paper, food, and feed, pharmaceutical, and biofuel industries. These industries demand xylanases that are functional under extreme conditions, such as high temperature, acidic/alkaline pH, and others, which are prevailing in bioprocessing industries. Despite the availability of several xylan-hydrolyzing enzymes from cultured microbes, there is a huge gap between what is available and what industries require. DNA manipulations as well as protein-engineering techniques are also not quite satisfactory in generating xylan-hydrolyzing extremozymes. With a compound annual growth rate of 6.6% of xylan-hydrolyzing enzymes in the global market, there is a need for xylanolytic extremozymes. Therefore, metagenomic approaches have been employed to uncover hidden xylanolytic genes that were earlier inaccessible in culture-dependent approaches. Appreciable success has been achieved in retrieving several unusual xylanolytic enzymes with novel and desirable characteristics from different extreme environments using functional and sequence-based metagenomic approaches. Moreover, the Carbohydrate Active Enzymes database includes approximately 400 GH-10 and GH-11 unclassified xylanases. This review discusses sources, characteristics, and applications of xylanolytic enzymes obtained through metagenomic approaches and their amelioration by genetic engineering techniques.
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Affiliation(s)
- Digvijay Verma
- Department of Microbiology, Babasaheb Bhimrao Ambedkar (Central) University, Lucknow, India
| | - Tulasi Satyanarayana
- Department of Biological Sciences and Engineering, Netaji Subhas University of Technology, Dwarka, New Delhi, India
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Díaz GV, Coniglio RO, Alvarenga AE, Zapata PD, Villalba LL, Fonseca MI. Secretomic analysis of cheap enzymatic cocktails of Aspergillus niger LBM 134 grown on cassava bagasse and sugarcane bagasse. Mycologia 2020; 112:663-676. [PMID: 32574526 DOI: 10.1080/00275514.2020.1763707] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Currently, agroindustrial wastes are little used for generating value-added products; hence, their use of these waste to produce enzymatic cocktails for the conversion of lignocellulosic biomass to fermentable sugars is a very interesting alternative in the second-generation bioethanol process. The Ascomycota fungus Aspergillus niger LBM 134 produces hydrolytic enzymes in large proportions. In this work, A. niger LBM 134 was grown on sugarcane and cassava bagasses under optimized conditions. To identify the extracellular enzymes involved in the degradation of these agroindustrial wastes, the secretomes of the culture supernatants of the fungus were analyzed and validated by biochemical assays of the enzymatic activities. A. niger LBM 134 secreted higher quantities of xylanases and accessory hemicellulases when it grew on sugarcane bagasse, whereas more cellulases, amylases, and pectinases were secreted when it grew on cassava bagasse. These findings suggest two promising enzyme cocktails for the hydrolysis of lignocellulose carbohydrate polymers to fermentable sugars. These bioinformatic analysis were functional validates through enzymatic biochemical assays that confirm the biotechnological potential of A. niger LBM 134 for the bioconversion of hemicellulosic substrates such as sugarcane and cassava bagasses.
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Affiliation(s)
- Gabriela Verónica Díaz
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología Misiones "María Ebe Reca" CONICET, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones , Ruta 12 km 7.5, C.P. 3300, Posadas, Argentina
| | - Romina Olga Coniglio
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología Misiones "María Ebe Reca" CONICET, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones , Ruta 12 km 7.5, C.P. 3300, Posadas, Argentina
| | - Adriana Elizabet Alvarenga
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología Misiones "María Ebe Reca" CONICET, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones , Ruta 12 km 7.5, C.P. 3300, Posadas, Argentina
| | - Pedro Darío Zapata
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología Misiones "María Ebe Reca" CONICET, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones , Ruta 12 km 7.5, C.P. 3300, Posadas, Argentina
| | - Laura Lidia Villalba
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología Misiones "María Ebe Reca" CONICET, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones , Ruta 12 km 7.5, C.P. 3300, Posadas, Argentina
| | - María Isabel Fonseca
- Laboratorio de Biotecnología Molecular, Instituto de Biotecnología Misiones "María Ebe Reca" CONICET, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones , Ruta 12 km 7.5, C.P. 3300, Posadas, Argentina
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10
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Neotropical termite microbiomes as sources of novel plant cell wall degrading enzymes. Sci Rep 2020; 10:3864. [PMID: 32123275 PMCID: PMC7052144 DOI: 10.1038/s41598-020-60850-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/24/2019] [Indexed: 11/08/2022] Open
Abstract
In this study, we used shotgun metagenomic sequencing to characterise the microbial metabolic potential for lignocellulose transformation in the gut of two colonies of Argentine higher termite species with different feeding habits, Cortaritermes fulviceps and Nasutitermes aquilinus. Our goal was to assess the microbial community compositions and metabolic capacity, and to identify genes involved in lignocellulose degradation. Individuals from both termite species contained the same five dominant bacterial phyla (Spirochaetes, Firmicutes, Proteobacteria, Fibrobacteres and Bacteroidetes) although with different relative abundances. However, detected functional capacity varied, with C. fulviceps (a grass-wood-feeder) gut microbiome samples containing more genes related to amino acid metabolism, whereas N. aquilinus (a wood-feeder) gut microbiome samples were enriched in genes involved in carbohydrate metabolism and cellulose degradation. The C. fulviceps gut microbiome was enriched specifically in genes coding for debranching- and oligosaccharide-degrading enzymes. These findings suggest an association between the primary food source and the predicted categories of the enzymes present in the gut microbiomes of each species. To further investigate the termite microbiomes as sources of biotechnologically relevant glycosyl hydrolases, a putative GH10 endo-β-1,4-xylanase, Xyl10E, was cloned and expressed in Escherichia coli. Functional analysis of the recombinant metagenome-derived enzyme showed high specificity towards beechwood xylan (288.1 IU/mg), with the optimum activity at 50 °C and a pH-activity range from 5 to 10. These characteristics suggest that Xy110E may be a promising candidate for further development in lignocellulose deconstruction applications.
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11
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Ghadikolaei KK, Sangachini ED, Vahdatirad V, Noghabi KA, Zahiri HS. An extreme halophilic xylanase from camel rumen metagenome with elevated catalytic activity in high salt concentrations. AMB Express 2019; 9:86. [PMID: 31209584 PMCID: PMC6579805 DOI: 10.1186/s13568-019-0809-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 06/06/2019] [Indexed: 11/22/2022] Open
Abstract
An extreme halophilic xylanase, designated as XylCMS, was characterized by cloning and expression of the encoding gene from a camel rumen metagenome. XylCMS proved to be a GH11 xylanase with high identity to a hypothetical glycosyl hydrolase from Ruminococcus flavefaciens. XylCMS with a molecular weight of about 47 kDa showed maximum activity at pH 6 and 55 °C. The enzyme activity was significantly stimulated by NaCl in 1–5 M concentrations. Interestingly, the optimum temperature was not influenced by NaCl but the Kcat of the enzyme was enhanced by 2.7-folds at 37 °C and 1.2-folds at 55 °C. The Km value was decreased with NaCl by 4.3-folds at 37 °C and 3.7-folds at 55 °C resulting in a significant increase in catalytic efficiency (Kcat/Km) by 11.5-folds at 37 °C and 4.4-folds at 55 °C. Thermodynamic analysis indicated that the activation energy (Ea) and enthalpy (∆H) of the reaction were decreased with NaCl by 2.4 and threefold, respectively. From the observations and the results of fluorescence spectroscopy, it was concluded that NaCl at high concentrations improves both the flexibility and substrate affinity of XylCMS that are crucial for catalytic activity by influencing substrate binding, product release and the energy barriers of the reaction. XylCMS as an extreme halophilic xylanase with stimulated activity in artificial seawater and low water activity conditions has potentials for application in industrial biotechnology.
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Affiliation(s)
- Tomohiko Matsuzawa
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
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13
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Myco-Degradation of Lignocellulose: An Update on the Reaction Mechanism and Production of Lignocellulolytic Enzymes by Fungi. Fungal Biol 2019. [DOI: 10.1007/978-3-030-23834-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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14
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Ngara TR, Zhang H. Recent Advances in Function-based Metagenomic Screening. GENOMICS PROTEOMICS & BIOINFORMATICS 2018; 16:405-415. [PMID: 30597257 PMCID: PMC6411959 DOI: 10.1016/j.gpb.2018.01.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/05/2018] [Accepted: 01/09/2018] [Indexed: 12/01/2022]
Abstract
Metagenomes from uncultured microorganisms are rich resources for novel enzyme genes. The methods used to screen the metagenomic libraries fall into two categories, which are based on sequence or function of the enzymes. The sequence-based approaches rely on the known sequences of the target gene families. In contrast, the function-based approaches do not involve the incorporation of metagenomic sequencing data and, therefore, may lead to the discovery of novel gene sequences with desired functions. In this review, we discuss the function-based screening strategies that have been used in the identification of enzymes from metagenomes. Because of its simplicity, agar plate screening is most commonly used in the identification of novel enzymes with diverse functions. Other screening methods with higher sensitivity are also employed, such as microtiter plate screening. Furthermore, several ultra-high-throughput methods were developed to deal with large metagenomic libraries. Among these are the FACS-based screening, droplet-based screening, and the in vivo reporter-based screening methods. The application of these novel screening strategies has increased the chance for the discovery of novel enzyme genes.
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Affiliation(s)
- Tanyaradzwa Rodgers Ngara
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, MOE Key Laboratory of Molecular Biophysics, Wuhan 430074, China
| | - Houjin Zhang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, MOE Key Laboratory of Molecular Biophysics, Wuhan 430074, China.
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Kim HB, Lee KT, Kim MJ, Lee JS, Kim KS. Identification and characterization of a novel KG42 xylanase (GH10 family) isolated from the black goat rumen-derived metagenomic library. Carbohydr Res 2018; 469:1-9. [PMID: 30170217 DOI: 10.1016/j.carres.2018.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/14/2018] [Accepted: 08/17/2018] [Indexed: 11/18/2022]
Abstract
This study was conducted to isolate and functionally characterize a novel xylan-degrading enzyme from the microbial metagenomes of black goat rumens. A novel gene, KG42, was isolated from one of the 17 xylan-degrading metagenomic fosmid clones obtained from black goat rumens. The KG42 gene, comprising a 1107 bp open reading frame, encodes a protein composed of 368 amino acids (41 kDa) with a glycosyl hydrolase family 10 (GH10) domain, consisting of a "salad-bowl" shaped tertiary structure (a typical 8-fold α/β barrel (α/β)8) and two catalytic residues. KG42 xylanase protein has at best 40% sequence identity with other homologous GH10 xylanase proteins. The enzyme displayed its optimum activity at pH 5.0 and 50 °C. The enzyme was thermally stable at pH and temperature ranges of 5.0-10.0 and 20-60 °C, respectively. Substrate specificity and hydrolytic patterns implied that the KG42 xylanase functions as an endo-β-1,4-xylanase (EC 3.2.1.8). The KG42 xylanase was also used for the preparation of bifidogenic xylan hydrolysates, demonstrating its potential applications toward preparing prebiotic xylooligosaccharides.
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Affiliation(s)
- Hye-Bin Kim
- Department of Food Science and Technology, Chung-Ang University, Ansung, 456-756, South Korea
| | - Kyung-Tai Lee
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, Rural Development Administration, Wanju, 565-851, South Korea
| | - Min-Ju Kim
- Department of Food Science and Technology, Chung-Ang University, Ansung, 456-756, South Korea
| | - Jin-Sung Lee
- Department of Biological Sciences, Kyonggi University, Suwon, 442-760, South Korea
| | - Keun-Sung Kim
- Department of Food Science and Technology, Chung-Ang University, Ansung, 456-756, South Korea.
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Yadav SK. Technological advances and applications of hydrolytic enzymes for valorization of lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2017; 245:1727-1739. [PMID: 28552567 DOI: 10.1016/j.biortech.2017.05.066] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 06/07/2023]
Abstract
Hydrolytic enzymes are indispensable tools in the production of various foodstuffs, drugs, and consumables owing to their applications in almost every industrial process nowadays. One of the foremost areas of interest involving the use of hydrolytic enzymes is in the transformation of lignocellulosic biomass into value added products. However, limitations of the processes due to inadequate enzyme activity and stability with a narrow range of pH and temperature optima often limit their effective usage. The innovative technologies, involving manipulation of enzyme activity and stability through mutagenesis, genetic engineering and metagenomics lead to a major leap in all the fields using hydrolytic enzymes. This article provides recent advancement towards the isolation and use of microbes for lignocellulosic biomass utilisation, microbes producing the hydrolytic enzymes, the modern age technologies used to manipulate and enhance the hydrolytic enzyme activity and the applications of such enzymes in value added products development from lignocellulosic biomass.
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Affiliation(s)
- Sudesh Kumar Yadav
- Center of Innovative and Applied Bioprocessing (CIAB), Knowledge City, Sector-81, Mohali, India.
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Shah RK, Patel AK, Davla DM, Parikh IK, Subramanian RB, Patel KC, Jakhesara SJ, Joshi CG. Molecular cloning, heterologous expression, and functional characterization of a cellulolytic enzyme (Cel PRII) from buffalo rumen metagenome. 3 Biotech 2017; 7:257. [PMID: 28733938 DOI: 10.1007/s13205-017-0895-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/12/2017] [Indexed: 01/02/2023] Open
Abstract
A cellulase encoding gene, Cel PRII, was identified from Mehsani buffalo rumen metagenome, and cloned and expressed in Escherichia coli BL21(DE3)pLysS. The 1170 bp full length gene encodes a 389 residue polypeptide (Cel PRII) containing a catalytic domain belonging to glycosyl hydrolase (GH) 5 family. The fusion protein consisting of the Cel PRII, thioredoxin tag and 6x Histidine tag with predicted molecular weight of 63 kDa when recovered from inclusion bodies under denaturing conditions, exhibited cellulolytic activity against carboxymethyl cellulose (CMC). Recombinant Cel PRII was stable in the pH range 4.0-10.0 with pH optima 6.0. The optimal reaction temperature of Cel PRII was 30 °C with more than 50% of its activity retained at the temperatures ranging from 0 to 50 °C. Cel PRII exhibited enhanced enzymatic activity in the presence of Mn2+ ions and was inhibited in the presence of chelating agent EDTA. The K m and V max values for CMC were found to be 166 mg/mL and 1292 IU/mg, respectively. Cel PRII identified in the present study may act as an excellent candidate for industrial applications, and may aid in lignocellulosic biomass conversion because of its potential cellulolytic activity, thermostability, and excellent pH stability.
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Affiliation(s)
- Ravi K Shah
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388110, India
- P. G. Department of Biosciences, Sardar Patel University, Bakrol, 388315, India
| | - Amrutlal K Patel
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388110, India
- Hester Biosciences Ltd., Merda-Adraj, Kadi, 382728, India
| | - Deepti M Davla
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388110, India
| | - Ishan K Parikh
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388110, India
- Zydus Vaccine Technology Centre, Changodar, Ahmedabad, 382213, India
| | | | - Kamlesh C Patel
- P. G. Department of Biosciences, Sardar Patel University, Bakrol, 388315, India
| | - Subhash J Jakhesara
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388110, India
| | - Chaitanya G Joshi
- Department of Animal Biotechnology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand, Gujarat, 388110, India.
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Gene Expression and Molecular Characterization of a Xylanase from Chicken Cecum Metagenome. Int J Microbiol 2017; 2017:4018398. [PMID: 28751915 PMCID: PMC5511640 DOI: 10.1155/2017/4018398] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 05/15/2017] [Accepted: 05/23/2017] [Indexed: 12/26/2022] Open
Abstract
A xylanase gene xynAMG1 with a 1,116-bp open reading frame, encoding an endo-β-1,4-xylanase, was cloned from a chicken cecum metagenome. The translated XynAMG1 protein consisted of 372 amino acids including a putative signal peptide of 23 amino acids. The calculated molecular mass of the mature XynAMG1 was 40,013 Da, with a theoretical pI value of 5.76. The amino acid sequence of XynAMG1 showed 59% identity to endo-β-1,4-xylanase from Prevotella bryantii and Prevotella ruminicola and 58% identity to that from Prevotella copri. XynAMG1 has two conserved motifs, DVVNE and TEXD, containing two active site glutamates and an invariant asparagine, characteristic of GH10 family xylanase. The xynAMG1 gene without signal peptide sequence was cloned and fused with thioredoxin protein (Trx.Tag) in pET-32a plasmid and overexpressed in Escherichia coli Tuner™(DE3)pLysS. The purified mature XynAMG1 was highly salt-tolerant and stable and displayed higher than 96% of its catalytic activity in the reaction containing 1 to 4 M NaCl. It was only slightly affected by common organic solvents added in aqueous solution to up to 5 M. This chicken cecum metagenome-derived xylanase has potential applications in animal feed additives and industrial enzymatic processes requiring exposure to high concentrations of salt and organic solvents.
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Maruthamuthu M, Jiménez DJ, van Elsas JD. Characterization of a furan aldehyde-tolerant β-xylosidase/α-arabinosidase obtained through a synthetic metagenomics approach. J Appl Microbiol 2017; 123:145-158. [PMID: 28489302 DOI: 10.1111/jam.13484] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/26/2017] [Accepted: 05/03/2017] [Indexed: 12/16/2022]
Abstract
AIMS The aim of the study was to characterize 10 hemicellulolytic enzymes obtained from a wheat straw-degrading microbial consortium. METHODS AND RESULTS Based on previous metagenomics analyses, 10 glycosyl hydrolases were selected, codon-optimized, synthetized, cloned and expressed in Escherichia coli. Nine of the overexpressed recombinant proteins accumulated in cellular inclusion bodies, whereas one, a 37·5-kDa protein encoded by gene xylM1989, was found in the soluble fractions. The resulting protein, denoted XylM1989, showed β-xylosidase and α-arabinosidase activities. It fell in the GH43 family and resembled a Sphingobacterium sp. protein. The XylM1989 showed optimum activity at 20°C and pH 8·0. Interestingly, it kept approximately 80% of its β-xylosidase activity in the presence of 0·5% (w/v) furfural and 0·1% (w/v) 5-hydroxymethylfurfural. Additionally, the presence of Ca2+ , Mg2+ and Mn2+ ions increased the enzymatic activity and conferred complete tolerance to 500 mmol l-1 of xylose. Protein XylM1989 is also able to release sugars from complex polysaccharides. CONCLUSION We report the characterization of a novel bifunctional hemicellulolytic enzyme obtained through a targeted synthetic metagenomics approach. SIGNIFICANCE AND IMPACT OF THE STUDY The properties of XylM1989 turn this protein into a promising enzyme that could be useful for the efficient saccharification of plant biomass.
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Affiliation(s)
- M Maruthamuthu
- Cluster of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - D J Jiménez
- Cluster of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - J D van Elsas
- Cluster of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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Sanjivkumar M, Silambarasan T, Palavesam A, Immanuel G. Biosynthesis, purification and characterization of β-1,4-xylanase from a novel mangrove associated actinobacterium Streptomyces olivaceus (MSU3) and its applications. Protein Expr Purif 2017; 130:1-12. [DOI: 10.1016/j.pep.2016.09.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 07/25/2016] [Accepted: 09/27/2016] [Indexed: 01/02/2023]
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21
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Xiao Y, Zhang Q, Luo Y, Zhang Y, Luo X, Wang Y, Cao W, Pinto VD, Liu Q, Li G. Neurospora crassa tox-1 Gene Encodes a pH- and Temperature-Tolerant Mini-Cellulase. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:4751-4757. [PMID: 27229865 DOI: 10.1021/acs.jafc.6b00043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cellulases that endure extreme conditions are essential in various industrial sectors. This study reports a mini-cellulase gene tox-1 from Neurospora crassa. The gene tox-1 was cloned in Escherichia coli after chimerization with the YebF gene and substitutions of certain isoleucine and valine with leucine residues. The yeast transformants could grow on rice straw-agar medium. The 44-amino acid peptide and its two mutant variants displayed potent cellulase activities in Congo Red assay and enzymatic assays. Conservative replacements with leucine have substantially increased the stabilities and half-lives of the peptides at alkaline pH and low and high temperatures and also the tolerance to organic solvents and surfactants, on the basis of activities toward cellose. The small size of the mini-cellulase would allow for commercially viable automatic chemical peptide synthesis. This work suggests that conservative leucine replacements may serve as a general strategy in the engineering of more robust enzymes with special features with little loss of activities.
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Affiliation(s)
| | | | | | - Ying Zhang
- Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
| | | | | | - Weiguo Cao
- Department of Genetics and Biochemistry, Clemson University , Clemson, South Carolina 29634, United States
| | - Vito De Pinto
- Department of Biomedicine and Biotechnology BIOMETEC, Section of Biology and Genetics, University of Catania , 95125 Catania, Italy
- National Institute for Biomembranes and Biosystems, Section of Catania, 95125 Catania, Italy
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Cheng J, Huang S, Jiang H, Zhang Y, Li L, Wang J, Fan C. Isolation and characterization of a non-specific endoglucanase from a metagenomic library of goat rumen. World J Microbiol Biotechnol 2015; 32:12. [DOI: 10.1007/s11274-015-1957-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 10/14/2015] [Indexed: 01/08/2023]
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Montella S, Amore A, Faraco V. Metagenomics for the development of new biocatalysts to advance lignocellulose saccharification for bioeconomic development. Crit Rev Biotechnol 2015; 36:998-1009. [PMID: 26381035 DOI: 10.3109/07388551.2015.1083939] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The world economy is moving toward the use of renewable and nonedible lignocellulosic biomasses as substitutes for fossil sources in order to decrease the environmental impact of manufacturing processes and overcome the conflict with food production. Enzymatic hydrolysis of the feedstock is a key technology for bio-based chemical production, and the identification of novel, less expensive and more efficient biocatalysts is one of the main challenges. As the genomic era has shown that only a few microorganisms can be cultured under standard laboratory conditions, the extraction and analysis of genetic material directly from environmental samples, termed metagenomics, is a promising way to overcome this bottleneck. Two screening methodologies can be used on metagenomic material: the function-driven approach of expression libraries and sequence-driven analysis based on gene homology. Both techniques have been shown to be useful for the discovery of novel biocatalysts for lignocellulose conversion, and they enabled identification of several (hemi)cellulases and accessory enzymes involved in (hemi)cellulose hydrolysis. This review summarizes the latest progress in metagenomics aimed at discovering new enzymes for lignocellulose saccharification.
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Affiliation(s)
- Salvatore Montella
- a Department of Chemical Sciences , University of Naples "Federico II", Complesso Universitario Monte S. Angelo , Naples , Italy
| | - Antonella Amore
- a Department of Chemical Sciences , University of Naples "Federico II", Complesso Universitario Monte S. Angelo , Naples , Italy
| | - Vincenza Faraco
- a Department of Chemical Sciences , University of Naples "Federico II", Complesso Universitario Monte S. Angelo , Naples , Italy
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Loaces I, Amarelle V, Muñoz-Gutierrez I, Fabiano E, Martinez A, Noya F. Improved ethanol production from biomass by a rumen metagenomic DNA fragment expressed in Escherichia coli MS04 during fermentation. Appl Microbiol Biotechnol 2015; 99:9049-60. [DOI: 10.1007/s00253-015-6801-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 06/21/2015] [Accepted: 06/24/2015] [Indexed: 10/23/2022]
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25
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Wang M, Lai GL, Nie Y, Geng S, Liu L, Zhu B, Shi Z, Wu XL. Synergistic function of four novel thermostable glycoside hydrolases from a long-term enriched thermophilic methanogenic digester. Front Microbiol 2015; 6:509. [PMID: 26052323 PMCID: PMC4441150 DOI: 10.3389/fmicb.2015.00509] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 05/08/2015] [Indexed: 12/25/2022] Open
Abstract
In biofuel production from lignocellulose, low thermostability and product inhibition strongly restrict the enzyme activities and production process. Application of multiple thermostable glycoside hydrolases, forming an enzyme "cocktail", can result in a synergistic action and therefore improve production efficiency and reduce operational costs. Therefore, increasing enzyme thermostabilities and compatibility are important for the biofuel industry. In this study, we reported the screening, cloning and biochemical characterization of four novel thermostable lignocellulose hydrolases from a metagenomic library of a long-term dry thermophilic methanogenic digester community, which were highly compatible with optimal conditions and specific activities. The optimal temperatures of the four enzymes, β-xylosidase, xylanase, β-glucosidase, and cellulase ranged from 60 to 75°C, and over 80% residual activities were observed after 2 h incubation at 50°C. Mixtures of these hydrolases retained high residual synergistic activities after incubation with cellulose, xylan, and steam-exploded corncob at 50°C for 72 h. In addition, about 55% dry weight of steam-exploded corncob was hydrolyzed to glucose and xylose by the synergistic action of the four enzymes at 50°C for 48 h. This work suggested that since different enzymes from a same ecosystem could be more compatible, screening enzymes from a long-term enriching community could be a favorable strategy.
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Affiliation(s)
- Meng Wang
- School of Biotechnology, Jiangnan University Wuxi, China ; Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China
| | - Guo-Li Lai
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China ; Institute of Engineering (Baotou), College of Engineering, Peking University Baotou, China
| | - Yong Nie
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China ; Institute of Engineering (Baotou), College of Engineering, Peking University Baotou, China
| | - Shuang Geng
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China
| | - Liming Liu
- School of Biotechnology, Jiangnan University Wuxi, China
| | - Baoli Zhu
- Institute of Microbiology, Chinese Academy of Sciences Beijing, China
| | - Zhongping Shi
- School of Biotechnology, Jiangnan University Wuxi, China
| | - Xiao-Lei Wu
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China ; Institute of Engineering (Baotou), College of Engineering, Peking University Baotou, China
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Matsuzawa T, Kaneko S, Yaoi K. Screening, identification, and characterization of a GH43 family β-xylosidase/α-arabinofuranosidase from a compost microbial metagenome. Appl Microbiol Biotechnol 2015; 99:8943-54. [DOI: 10.1007/s00253-015-6647-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 04/09/2015] [Accepted: 04/19/2015] [Indexed: 01/09/2023]
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Abstract
Metagenomics deals with the isolation of genetic material directly recovered from environmental samples. Metagenomics as an approach has emerged over the past two decades to elucidate a host of microbial communities inhabiting a specific niche with the goal of understanding their genetic diversity, population structure, and ecological role played by them. A number of new and novel molecules with significant functionalities and applications have been identified through this approach. In fact, many investigators are engaged in this field to unlock the untapped genetic resources with funding from governments sector. The sustainable economic future of modern industrialized societies requires the development of novel molecules, enzymes, processes, products, and applications. Metagenomics can also be applied to solve practical challenges in the field of medicine, agriculture, sustainability, and ecology. Metagenomics promises to provide new molecules and novel enzymes with diverse functions and enhanced features compared to the enzymes from the culturable microorganisms. Besides the application of metagenomics for unlocking novel biocatalysts from nature, it also has found applications in fields as diverse as bioremediation, personalized medicine, xenobiotic metabolism, and so forth.
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Guazzaroni ME, Silva-Rocha R, Ward RJ. Synthetic biology approaches to improve biocatalyst identification in metagenomic library screening. Microb Biotechnol 2014; 8:52-64. [PMID: 25123225 PMCID: PMC4321373 DOI: 10.1111/1751-7915.12146] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/22/2014] [Accepted: 06/28/2014] [Indexed: 11/28/2022] Open
Abstract
There is a growing demand for enzymes with improved catalytic performance or tolerance to process-specific parameters, and biotechnology plays a crucial role in the development of biocatalysts for use in industry, agriculture, medicine and energy generation. Metagenomics takes advantage of the wealth of genetic and biochemical diversity present in the genomes of microorganisms found in environmental samples, and provides a set of new technologies directed towards screening for new catalytic activities from environmental samples with potential biotechnology applications. However, biased and low level of expression of heterologous proteins in Escherichia coli together with the use of non-optimal cloning vectors for the construction of metagenomic libraries generally results in an extremely low success rate for enzyme identification. The bottleneck arising from inefficient screening of enzymatic activities has been addressed from several perspectives; however, the limitations related to biased expression in heterologous hosts cannot be overcome by using a single approach, but rather requires the synergetic implementation of multiple methodologies. Here, we review some of the principal constraints regarding the discovery of new enzymes in metagenomic libraries and discuss how these might be resolved by using synthetic biology methods.
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Characterization and high-level expression of a metagenome-derived alkaline pectate lyase in recombinant Escherichia coli. Process Biochem 2014. [DOI: 10.1016/j.procbio.2013.10.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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30
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Gruninger RJ, Gong X, Forster RJ, McAllister TA. Biochemical and kinetic characterization of the multifunctional β-glucosidase/β-xylosidase/α-arabinosidase, Bgxa1. Appl Microbiol Biotechnol 2013; 98:3003-12. [DOI: 10.1007/s00253-013-5191-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/06/2013] [Accepted: 08/11/2013] [Indexed: 12/28/2022]
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