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Bombardi L, Orlando M, Aulitto M, Fusco S. Thermophilic Hemicellulases Secreted by Microbial Consortia Selected from an Anaerobic Digester. Int J Mol Sci 2024; 25:9887. [PMID: 39337375 PMCID: PMC11432564 DOI: 10.3390/ijms25189887] [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: 07/24/2024] [Revised: 08/30/2024] [Accepted: 09/09/2024] [Indexed: 09/30/2024] Open
Abstract
The rise of agro-industrial activities over recent decades has exponentially increased lignocellulose biomasses (LCB) production. LCB serves as a cost-effective source for fermentable sugars and other renewable chemicals. This study explores the use of microbial consortia, particularly thermophilic consortia, for LCB deconstruction. Thermophiles produce stable enzymes that retain activity under industrial conditions, presenting a promising approach for LCB conversion. This research focused on two microbial consortia (i.e., microbiomes) that were analyzed for enzyme production using a cheap medium, i.e., a mixture of spent mushroom substrate (SMS) and digestate. The secreted xylanolytic enzymes were characterized in terms of temperature and pH optima, thermal stability, and hydrolysis products from LCB-derived polysaccharides. These enzymes showed optimal activity aligning with common biorefinery conditions and outperformed a formulated enzyme mixture in thermostability tests in the digestate. Phylogenetic and genomic analyses highlighted the genetic diversity and metabolic potential of these microbiomes. Bacillus licheniformis was identified as a key species, with two distinct strains contributing to enzyme production. The presence of specific glycoside hydrolases involved in the cellulose and hemicellulose degradation underscores these consortia's capacity for efficient LCB conversion. These findings highlight the potential of thermophilic microbiomes, isolated from an industrial environment, as a robust source of robust enzymes, paving the way for more sustainable and cost-effective bioconversion processes in biofuel and biochemical production and other biotechnological applications.
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Affiliation(s)
- Luca Bombardi
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Marco Orlando
- Department of Biotechnology and Biosciences, University of Milano Bicocca, 20126 Milano, Italy
| | - Martina Aulitto
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Salvatore Fusco
- Biochemistry and Industrial Biotechnology (BIB) Laboratory, Department of Biotechnology, University of Verona, 37134 Verona, Italy
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Akram F, Fatima T, Ibrar R, Shabbir I, Shah FI, Haq IU. Trends in the development and current perspective of thermostable bacterial hemicellulases with their industrial endeavors: A review. Int J Biol Macromol 2024; 265:130993. [PMID: 38508567 DOI: 10.1016/j.ijbiomac.2024.130993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 03/12/2024] [Accepted: 03/17/2024] [Indexed: 03/22/2024]
Abstract
Hemicellulases are enzymes that hydrolyze hemicelluloses, common polysaccharides in nature. Thermophilic hemicellulases, derived from microbial strains, are extensively studied as natural biofuel sources due to the complex structure of hemicelluloses. Recent research aims to elucidate the catalytic principles, mechanisms and specificity of hemicellulases through investigations into their high-temperature stability and structural features, which have applications in biotechnology and industry. This review article targets to serve as a comprehensive resource, highlighting the significant progress in the field and emphasizing the vital role of thermophilic hemicellulases in eco-friendly catalysis. The primary goal is to improve the reliability of hemicellulase enzymes obtained from thermophilic bacterial strains. Additionally, with their ability to break down lignocellulosic materials, hemicellulases hold immense potential for biofuel production. Despite their potential, the commercial viability is hindered by their high enzyme costs, necessitating the development of efficient bioprocesses involving waste pretreatment with microbial consortia to overcome this challenge.
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Affiliation(s)
- Fatima Akram
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan.
| | - Taseer Fatima
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Ramesha Ibrar
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Ifrah Shabbir
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | | | - Ikram Ul Haq
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan; Pakistan Academy of Sciences, Islamabad, Pakistan
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Mustafa M, Ali L, Islam W, Noman A, Zhou C, Shen L, Zhu T, Can L, Nasif O, Gasparovic K, latif F, Gao J. Heterologous expression and characterization of glycoside hydrolase with its potential applications in hyperthermic environment. Saudi J Biol Sci 2022; 29:751-757. [PMID: 35197741 PMCID: PMC8847942 DOI: 10.1016/j.sjbs.2021.09.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/07/2021] [Accepted: 09/29/2021] [Indexed: 01/25/2023] Open
Abstract
With the progressive focus on renewable energy via biofuels production from lignocellulosic biomass, cellulases are the key enzymes that play a fundamental role in this regard. This study aims to unravel the characteristics of Thermotoga maritima MSB8 (Tma) (a hyperthermophile from hot springs) thermostable glycoside hydrolase enzyme. Here, a glycoside hydrolase gene of Thermotoga maritima (Tma) was heterologously expressed and characterized. The gene was placed in the pQE-30 expression vector under the T5 promotor, and the construct pQE-30-Gh was then successfully integrated into Escherichia coli BL21 (DH5α) genome by transformation. Sequence of the glycoside hydrolase contained an open reading frame of 2.124 kbp, encoded a polypeptide of 721 amino acid residues. The molecular weight of the recombinant protein estimated was 79 kDa. The glycoside hydrolase was purified by Ni+2-NTA affinity chromatography and its enzymatic activity was investigated. The recombinant enzyme is highly stable within an extreme pH range (2.0–7.0) and highly thermostable at 80 °C for 72 h indicating its viability in hyperthermic environment and acidic nature. Moreover, the Ca2+ and Mn2+ introduction stimulated the residual activity of recombinant enzyme. Conclusively, the thermostable glycoside hydrolase possesses potential to be exploited for industrial applications at hyperthermic environment.
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Affiliation(s)
- Muhammad Mustafa
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Liaqat Ali
- Kansas State University, Manhattan, KS 66506, United States
| | - Waqar Islam
- College of Geography, Fujian Normal University, Fuzhou 350007, China
| | - Ali Noman
- Department of Botany, Government College University, Faisalabad 38040, Pakistan
| | - Chengzeng Zhou
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Linsong Shen
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Taoting Zhu
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Liu Can
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Omaima Nasif
- Department of Physiology, College of Medicine and King Khalid University Hospital, King Saud University, Medical City, PO Box-2925, Riyadh 11461, Saudi Arabia
| | - Kristina Gasparovic
- Department of Plant Physiology, Slovak University of Agriculture, A.Hlinku 2, 94976, Slovakia
| | - Farooq latif
- National Institute for Biotechnology and Genetic Engineering, Faisalabad 38000, Pakistan
| | - Jiangtao Gao
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Corresponding author at: Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Bai X, Yuan X, Wen A, Li J, Bai Y, Shao T. Cloning, expression and characterization of a cold-adapted endo-1, 4- β-glucanase from Citrobacter farmeri A1, a symbiotic bacterium of Reticulitermes labralis. PeerJ 2016; 4:e2679. [PMID: 27843715 PMCID: PMC5103814 DOI: 10.7717/peerj.2679] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/12/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Many biotechnological and industrial applications can benefit from cold-adapted EglCs through increased efficiency of catalytic processes at low temperature. In our previous study, Citrobacter farmeri A1 which was isolated from a wood-inhabiting termite Reticulitermes labralis could secrete a cold-adapted EglC. However, its EglC was difficult to purify for enzymatic properties detection because of its low activity (0.8 U/ml). The objective of the present study was to clone and express the C. farmeri EglC gene in Escherichia coli to improve production level and determine the enzymatic properties of the recombinant enzyme. METHODS The EglC gene was cloned from C. farmeri A1 by thermal asymmetric interlaced PCR. EglC was transformed into vector pET22b and functionally expressed in E. coli. The recombination protein EglC22b was purified for properties detection. RESULTS SDS-PAGE revealed that the molecular mass of the recombinant endoglucanase was approximately 42 kDa. The activity of the E. coli pET22b-EglC crude extract was 9.5 U/ml. Additionally, it was active at pH 6.5-8.0 with an optimum pH of 7.0. The recombinant enzyme had an optimal temperature of 30-40 °C and exhibited >50% relative activity even at 5 °C, whereas it lost approximately 90% of its activity after incubation at 60 °C for 30 min. Its activity was enhanced by Co2+ and Fe3+, but inhibited by Cd2+, Zn2+, Li+, Triton X-100, DMSO, acetonitrile, Tween 80, SDS, and EDTA. CONCLUSION These biochemical properties indicate that the recombinant enzyme is a cold-adapted endoglucanase that can be used for various industrial applications.
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Affiliation(s)
- Xi Bai
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University , Nanjing , China
| | - Xianjun Yuan
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University , Nanjing , China
| | - Aiyou Wen
- College of Animal Science, University of Science and Technology of Anhui , Fengyang , China
| | - Junfeng Li
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University , Nanjing , China
| | - Yunfeng Bai
- Institute of Agricultural Resource and Environment, Jiangsu Academy of Agricultural Sciences , Nanjing , China
| | - Tao Shao
- Institute of Ensiling and Processing of Grass, Nanjing Agricultural University , Nanjing , China
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HELIANTI IS, ULFAH MARIA, NURHAYATI NIKNIK, MULYAWATI LINA. Cloning, Sequencing, and Expression of the Gene Encoding a Family 9 Cellulase from Bacillus licheniformis F11 in Escherichia coli and Bacillus megaterium, and Characterization of the Recombinant Enzymes. MICROBIOLOGY INDONESIA 2014. [DOI: 10.5454/mi.8.4.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Seo JK, Park TS, Kwon IH, Piao MY, Lee CH, Ha JK. Characterization of Cellulolytic and Xylanolytic Enzymes of Bacillus licheniformis JK7 Isolated from the Rumen of a Native Korean Goat. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2014; 26:50-8. [PMID: 25049705 PMCID: PMC4093055 DOI: 10.5713/ajas.2012.12506] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 11/02/2012] [Accepted: 10/26/2012] [Indexed: 12/01/2022]
Abstract
A facultative bacterium producing cellulolytic and hemicellulolytic enzymes was isolated from the rumen of a native Korean goat. The bacterium was identified as a Bacillus licheniformis on the basis of biochemical and morphological characteristics and 16S rDNA sequences, and has been designated Bacillus licheniformis JK7. Endoglucanase activities were higher than those of β-glucosidase and xylanase at all temperatures. Xylanase had the lowest activity among the three enzymes examined. The optimum temperature for the enzymes of Bacillus licheniformis JK7 was 70°C for endoglucanase (0.75 U/ml) and 50°C for β-glucosidase and xylanase (0.63 U/ml, 0.44 U/ml, respectively). All three enzymes were stable at a temperature range of 20 to 50°C. At 50°C, endoglucanse, β-glucosidase, and xylanase had 90.29, 94.80, and 88.69% residual activity, respectively. The optimal pH for the three enzymes was 5.0, at which their activity was 1.46, 1.10, and 1.08 U/ml, respectively. The activity of all three enzymes was stable in the pH range of 3.0 to 6.0. Endoglucanase activity was increased 113% by K+, while K+, Zn+, and tween 20 enhanced β-glucosidase activity. Xylanase showed considerable activity even in presence of selected chemical additives, with the exception of Mn2+ and Cu2+. The broad range of optimum temperatures (20 to 40°C) and the stability under acidic pH (4 to 6) suggest that the cellulolytic enzymes of Bacillus licheniformis JK7 may be good candidates for use in the biofuel industry.
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Affiliation(s)
- J K Seo
- Department of Agriculture Biotechnology, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea
| | - T S Park
- Department of Agriculture Biotechnology, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea
| | - I H Kwon
- Department of Agriculture Biotechnology, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea
| | - M Y Piao
- Department of Agriculture Biotechnology, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea
| | - C H Lee
- Department of Agriculture Biotechnology, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea
| | - Jong K Ha
- Department of Agriculture Biotechnology, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Science, Seoul National University, Seoul 151-742, Korea
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de Almeida MN, Falkoski DL, Guimarães VM, Ramos HJDO, Visser EM, Maitan-Alfenas GP, de Rezende ST. Characteristics of free endoglucanase and glycosidases multienzyme complex from Fusarium verticillioides. BIORESOURCE TECHNOLOGY 2013; 143:413-22. [PMID: 23819978 DOI: 10.1016/j.biortech.2013.06.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/05/2013] [Accepted: 06/08/2013] [Indexed: 05/24/2023]
Abstract
A novel multienzyme complex, E1C, and a free endoglucanase, E2 (GH5), from Fusarium verticillioides were purified. The E1C contained two endoglucanases (GH6 and GH10), one cellobiohydrolase (GH7) and one xylanase (GH10). Maximum activity was observed at 80 °C for both enzymes and they were thermostable at 50 and 60 °C. The activation energies for E1C and E2 were 21.3 and 27.5 kJ/mol, respectively. The KM for E1C was 10.25 g/L while for E2 was 6.58 g/L. Both E1C and E2 were activated by Mn(2+) and CoCl2 while they were inhibited by SDS, CuSO4, FeCl3, AgNO4, ZnSO4 and HgCl2. E1C and E2 presented endo-β-1,3-1,4-glucanase activity. E1C presented crescent activity towards cellopentaose, cellotetraose and cellotriose. E2 hydrolyzed the substrates cellopentaose, cellotetraose and cellotriose with the same efficiency. E1C showed a higher stability and a better hydrolysis performance than E2, suggesting advantages resulting from the physical interaction between proteins.
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Affiliation(s)
- Maíra N de Almeida
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil
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Yan P, Su L, Chen J, Wu J. Heterologous expression and biochemical characterization of an endo-β-1,4-glucanase fromThermobifida fusca. Biotechnol Appl Biochem 2013; 60:348-55. [DOI: 10.1002/bab.1097] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 01/08/2013] [Indexed: 11/10/2022]
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Bhalla A, Bansal N, Kumar S, Bischoff KM, Sani RK. Improved lignocellulose conversion to biofuels with thermophilic bacteria and thermostable enzymes. BIORESOURCE TECHNOLOGY 2013; 128:751-9. [PMID: 23246299 DOI: 10.1016/j.biortech.2012.10.145] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 09/20/2012] [Accepted: 10/29/2012] [Indexed: 05/07/2023]
Abstract
Second-generation feedstock, especially nonfood lignocellulosic biomass is a potential source for biofuel production. Cost-intensive physical, chemical, biological pretreatment operations and slow enzymatic hydrolysis make the overall process of lignocellulosic conversion into biofuels less economical than available fossil fuels. Lignocellulose conversions carried out at ≤ 50 °C have several limitations. Therefore, this review focuses on the importance of thermophilic bacteria and thermostable enzymes to overcome the limitations of existing lignocellulosic biomass conversion processes. The influence of high temperatures on various existing lignocellulose conversion processes and those that are under development, including separate hydrolysis and fermentation, simultaneous saccharification and fermentation, and extremophilic consolidated bioprocess are also discussed.
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Affiliation(s)
- Aditya Bhalla
- Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, USA
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Wagschal K, Lee CC. Microplate-based active/inactive 1° screen for biomass degrading enzyme library purification and gene discovery. J Microbiol Methods 2012; 89:83-5. [DOI: 10.1016/j.mimet.2012.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 01/11/2012] [Accepted: 01/12/2012] [Indexed: 11/16/2022]
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Graham JE, Clark ME, Nadler DC, Huffer S, Chokhawala HA, Rowland SE, Blanch HW, Clark DS, Robb FT. Identification and characterization of a multidomain hyperthermophilic cellulase from an archaeal enrichment. Nat Commun 2011; 2:375. [DOI: 10.1038/ncomms1373] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 06/02/2011] [Indexed: 11/09/2022] Open
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Ko CH, Tsai CH, Lin PH, Chang KC, Tu J, Wang YN, Yang CY. Characterization and pulp refining activity of a Paenibacillus campinasensis cellulase expressed in Escherichia coli. BIORESOURCE TECHNOLOGY 2010; 101:7882-7888. [PMID: 20541400 DOI: 10.1016/j.biortech.2010.05.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 05/16/2010] [Accepted: 05/17/2010] [Indexed: 05/29/2023]
Abstract
The Cel-BL11 gene from Paenibacillus campinasensis BL11 was cloned and expressed in Escherichia coli as a His-tag fusion protein. Zymographic analysis of the recombinant protein revealed cellulase activity corresponding to a protein with a 38-kDa molecular weight. The optimum temperature and pH for purified cellulase were 60 °C and pH 7.0, respectively. The enzyme retained more than 80% activity after 8h at 60 °C at pH 6 and 7. The cellulase has a Km of 11.25 mg/ml and a Vmax of 1250 μmol/min/mg with carboxylmethyl cellulose (CMC). Then enzyme was active on Avicel, swollen Avicel, CMC, barley β-glucan, laminarin in the presence of 100 mM acetate buffer. It was inhibited by Hg²⁺, Cu²⁺ and Zn²⁺. Significant kraft pulp refining energy saving, 10%, was exhibited by the pretreatment of this cellulase applied at 2 IU per gram of oven-dried pulp. Broad pH and temperature stability render this cellulase a convenient applicability toward current mainstream biomass conversion and other industrial processes.
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Affiliation(s)
- Chun-Han Ko
- School of Forestry and Resource Conservation, National Taiwan University, Taipei 10617, Taiwan, ROC.
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van Dyk JS, Sakka M, Sakka K, Pletschke BI. Identification of endoglucanases, xylanases, pectinases and mannanases in the multi-enzyme complex of Bacillus licheniformis SVD1. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2010.05.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Nurachman. Cloning of the Endoglucanase Gene from a Bacillus amyloliquefaciens PSM 3.1 in Escherichia coli Revealed Catalytic Triad Residues Thr-His-Glu. ACTA ACUST UNITED AC 2010. [DOI: 10.3844/ajbbsp.2010.268.274] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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van Dyk JS, Sakka M, Sakka K, Pletschke BI. The cellulolytic and hemi-cellulolytic system of Bacillus licheniformis SVD1 and the evidence for production of a large multi-enzyme complex. Enzyme Microb Technol 2009. [DOI: 10.1016/j.enzmictec.2009.06.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Wang Y, Yuan H, Wang J, Yu Z. Truncation of the cellulose binding domain improved thermal stability of endo-beta-1,4-glucanase from Bacillus subtilis JA18. BIORESOURCE TECHNOLOGY 2009; 100:345-9. [PMID: 18632263 DOI: 10.1016/j.biortech.2008.06.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 06/01/2008] [Accepted: 06/04/2008] [Indexed: 05/23/2023]
Abstract
The C-terminus region of endo-beta-glucanase Egl499 from Bacillus subtilis JA18 was suggested to be a putative family 3 cellulose-binding domain (CBD) by computer analysis. To prove this proposal, C-terminus truncation mutant Egl330 was constructed and expressed. Compared with Egl499, Egl330 lost the cellulose binding capability at 4 degrees C, confirming the C-terminus region was a CBD. Binding of the CBD to Avicel was inhibited by carboxymethylcellulose (CMC), but not by barley beta-glucan and glucose at concentration of 0.1% and 0.5%. Kinetic analysis showed both the turnover rate (k(cat)) and the catalytic efficiency (k(cat)/K(m)) of Egl330 increased for the substrate CMC compared to Egl499. A great improvement in thermal stability was observed in Egl330. The half life of Egl330 at 65 degrees C increased to three folds that of Egl499, from 10 to 29 min. After treated at 80 degrees C for 10 min, Egl330 could recover more than 60% of its original activity while Egl499 only recovered 12% activity. UV spectrometry analysis showed Egl330 and Egl499 differed in refolding efficiency after heat treatment.
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Affiliation(s)
- Yujuan Wang
- Key Laboratory of Ion Beam Bioengineering, Chinese Academy of Sciences, Hefei, PR China
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Xia W, Liu P, Liu J. Advance in chitosan hydrolysis by non-specific cellulases. BIORESOURCE TECHNOLOGY 2008; 99:6751-6762. [PMID: 18328693 DOI: 10.1016/j.biortech.2008.01.011] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 12/25/2007] [Accepted: 01/03/2008] [Indexed: 05/26/2023]
Abstract
Besides the specific chitinase, chitosanase and lysozyme, chitosan also could be hydrolyzed by some non-specific enzymes such as cellulase, protease, lipase and pepsin, especially cellulase, which show high activity on chitosan. Almost all the cellulases produced by different kinds of microorganisms could degrade chitosan to chitooligomers. The existence of bifunctional enzymes with cellulase and chitosanase activity is one of the reasons for cellulase on chitosan hydrolysis. The bifunctional cellulase-chitosanases mainly belong to glycoside hydrolase family 8 (GH-8), few belong to GH-5 and GH-7, according to the homogeneity analysis of amino acids sequences. Their three dimensional structures however have not been clearly determined. This paper may serve as a guide for a further study on the relationship between structure and function of chitosanolytic cellulases.
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Affiliation(s)
- Wenshui Xia
- Wuhan Polytechnic University, Wuhan, 430023 Hubei, PR China.
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