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Leis B, Angelov A, Li H, Liebl W. Genetic analysis of lipolytic activities in Thermus thermophilus HB27. J Biotechnol 2014; 191:150-7. [DOI: 10.1016/j.jbiotec.2014.07.448] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/17/2014] [Accepted: 07/25/2014] [Indexed: 11/28/2022]
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52
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Glutaraldehyde cross-linking of immobilized thermophilic esterase on hydrophobic macroporous resin for application in poly(ε-caprolactone) synthesis. Molecules 2014; 19:9838-49. [PMID: 25006789 PMCID: PMC6270815 DOI: 10.3390/molecules19079838] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/03/2014] [Accepted: 07/04/2014] [Indexed: 11/24/2022] Open
Abstract
The immobilized thermophilic esterase from Archaeoglobus fulgidus was successfully constructed through the glutaraldehyde-mediated covalent coupling after its physical adsorption on a hydrophobic macroporous resin, Sepabeads EC-OD. Through 0.05% glutaraldehyde treatment, the prevention of enzyme leaching and the maintenance of catalytic activity could be simultaneously realized. Using the enzymatic ring-opening polymerization of ε-caprolactone as a model, effects of organic solvents and reaction temperature on the monomer conversion and product molecular weight were systematically investigated. After the optimization of reaction conditions, products were obtained with 100% monomer conversion and Mn values lower than 1010 g/mol. Furthermore, the cross‑linked immobilized thermophilic esterase exhibited an excellent operational stability, with monomer conversion values exceeding 90% over the course of 12 batch reactions, still more than 80% after 16 batch reactions.
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Killens-Cade R, Turner R, MacInnes C, Grunden A. Characterization of a Thermostable, Recombinant Carboxylesterase from the Hyperthermophilic Archaeon <em>Metallosphaera sedula</em> DSM5348. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/aer.2014.21001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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54
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Falcicchio P, Levisson M, Kengen SWM, Koutsopoulos S. (Hyper)thermophilic enzymes: production and purification. Methods Mol Biol 2014; 1129:487-496. [PMID: 24648095 DOI: 10.1007/978-1-62703-977-2_34] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The discovery of thermophilic and hyperthermophilic microorganisms, thriving at environmental temperatures near or above 100 °C, has revolutionized our ideas about the upper temperature limit at which life can exist. The characterization of (hyper)thermostable proteins has broadened our understanding and presented new opportunities for solving one of the most challenging problems in biophysics: how is structural stability and biological function maintained at high temperatures where "normal" proteins undergo dramatic structural changes? In our laboratory we have purified and studied many thermostable and hyperthermostable proteins in an attempt to determine the molecular basis of heat stability. Here, we present methods to express such proteins and enzymes in E. coli and provide a general protocol for overproduction and purification. The ability to produce enzymes that retain their stability and activity at elevated temperatures creates exciting opportunities for a wide range of biocatalytic applications.
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Stergiou PY, Foukis A, Filippou M, Koukouritaki M, Parapouli M, Theodorou LG, Hatziloukas E, Afendra A, Pandey A, Papamichael EM. Advances in lipase-catalyzed esterification reactions. Biotechnol Adv 2013; 31:1846-59. [DOI: 10.1016/j.biotechadv.2013.08.006] [Citation(s) in RCA: 270] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 11/30/2022]
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Song C, Sheng L, Zhang X. Immobilization and characterization of a thermostable lipase. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2013; 15:659-667. [PMID: 23748908 DOI: 10.1007/s10126-013-9515-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 05/16/2013] [Indexed: 06/02/2023]
Abstract
Lipases have found a number of commercial applications. However, thermostable lipase immobilized on nanoparticle is not extensively characterized. In this study, a recombinant thermostable lipase (designated as TtL) from Thermus thermophilus WL was expressed in Escherichia coli and immobilized onto 3-APTES-modified Fe3O4@SiO2 supermagnetic nanoparticles. Based on analyses with tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer observation, the diameter of immobilized lipase nanoparticle was 18.4 (± 2.4) nm, and its saturation magnetization value was 52.3 emu/g. The immobilized lipase could be separated from the reaction medium rapidly and easily in a magnetic field. The biochemical characterizations revealed that, comparing with the free one, the immobilized lipase exhibited better resistance to temperature, pH, metal ions, enzyme inhibitors, and detergents. The K m value for the immobilized TtL (2.56 mg/mL) was found to be lower than that of the free one (3.74 mg/mL), showing that the immobilization improved the affinity of lipase for its substrate. In addition, the immobilized TtL exhibited good reusability. It retained more than 79.5 % of its initial activity after reusing for 10 cycles. Therefore, our study presented that the possibility of the efficient reuse of the thermostable lipase immobilized on supermagnetic nanoparticles made it attractive from the viewpoint of practical application.
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Affiliation(s)
- Chongfu Song
- Key Laboratory of Conservation Biology for Endangered Wildlife of Ministry of Education and College of Life Sciences, Zhejiang University, Hangzhou, 310058, The People's Republic of China
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Nam JK, Park YJ, Lee HB. Cloning, expression, purification, and characterization of a thermostable esterase from the archaeon Sulfolobus solfataricus P1. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.05.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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58
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Characterization of a cold-adapted and salt-tolerant esterase from a psychrotrophic bacterium Psychrobacter pacificensis. Extremophiles 2013; 17:809-19. [DOI: 10.1007/s00792-013-0562-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 07/09/2013] [Indexed: 10/26/2022]
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59
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Production, Purification and Partial Characterization of Four Lipases from a Thermophile Isolated from Deception Island. Lipids 2013; 48:527-33. [DOI: 10.1007/s11745-013-3771-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
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60
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Tao W, Shengxue F, Duobin M, Xuan Y, Congcong D, Xihua W. Characterization of a new thermophilic and acid tolerant esterase from Thermotoga maritima capable of hydrolytic resolution of racemic ketoprofen ethyl ester. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2012.08.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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61
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Leis B, Angelov A, Liebl W. Screening and expression of genes from metagenomes. ADVANCES IN APPLIED MICROBIOLOGY 2013; 83:1-68. [PMID: 23651593 DOI: 10.1016/b978-0-12-407678-5.00001-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Microorganisms are the most abundant and widely spread organisms on earth. They colonize a huge variety of natural and anthropogenic environments, including very specialized ecological niches and even extreme habitats, which are made possible by the immense metabolic diversity and genetic adaptability of microbes. As most of the organisms from environmental samples defy cultivation, cultivation-independent metagenomics approaches have been applied since more than one decade to access and characterize the phylogenetic diversity in microbial communities as well as their metabolic potential and ecological functions. Thereby, metagenomics has fully emerged as an own scientific field for mining new biocatalysts for many industrially relevant processes in biotechnology and pharmaceutics. This review summarizes common metagenomic approaches ranging from sampling, isolation of nucleic acids, construction of metagenomic libraries and their evaluation. Sequence-based screenings implement next-generation sequencing platforms, microarrays or PCR-based methods, while function-based analysis covers heterologous expression of metagenomic libraries in diverse screening setups. Major constraints and advantages of each strategy are described. The importance of alternative host-vector systems is discussed, and in order to underline the role of phylogenetic and physiological distance from the gene donor and the expression host employed, a case study is presented that describes the screening of a genomic library from an extreme thermophilic bacterium in both Escherichia coli and Thermus thermophilus. Metatranscriptomics, metaproteomics and single-cell-based methods are expected to complement metagenomic screening efforts to identify novel biocatalysts from environmental samples.
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Affiliation(s)
- Benedikt Leis
- Lehrstuhl für Mikrobiologie, Technische Universität München, Freising, Bavaria, Germany
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62
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Hedge MK, Gehring AM, Adkins CT, Weston LA, Lavis LD, Johnson RJ. The structural basis for the narrow substrate specificity of an acetyl esterase from Thermotoga maritima. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:1024-30. [DOI: 10.1016/j.bbapap.2012.05.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 05/09/2012] [Accepted: 05/22/2012] [Indexed: 10/28/2022]
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63
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Angkawidjaja C, Koga Y, Takano K, Kanaya S. Structure and stability of a thermostable carboxylesterase from the thermoacidophilic archaeon Sulfolobus tokodaii. FEBS J 2012; 279:3071-84. [PMID: 22748144 DOI: 10.1111/j.1742-4658.2012.08687.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hormone-sensitive lipase (HSL) family is comprised of carboxylesterases and lipases with similarity to mammalian HSL. Thermophilic enzymes of this family have a high potential for use in biocatalysis. We prepared and crystallized a carboxylesterase of the HSL family from Sulfolobus tokodaii (Sto-Est), and determined its structures in the presence and absence of an inhibitor. Sto-Est forms a dimer in solution and the crystal structure suggests the presence of a stable biological dimer. We identified a residue close to the dimer interface, R267, which is conserved in archaeal enzymes of HSL family and is in close proximity to the same residue from the other monomer. Mutations of R267 to Glu, Gly and Lys were conducted and the resultant R267 mutants were characterized and crystallized. The structures of R267E, R267G and R267K are highly similar to that of Sto-Est with only slight differences in atomic coordinates. The dimerized states of R267E and R267G are unstable under denaturing conditions or at high temperature, as shown by a urea-induced dimer dissociation experiment and molecular dynamics simulation. R267E is the most unstable mutant protein, followed by R267G and R267K, as shown by the thermal denaturation curve and optimum temperature for activity. From the data, we discuss the importance of R267 in maintaining the dimer integrity of Sto-Est.
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Affiliation(s)
- Clement Angkawidjaja
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, Japan.
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64
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Liszka MJ, Clark ME, Schneider E, Clark DS. Nature Versus Nurture: Developing Enzymes That Function Under Extreme Conditions. Annu Rev Chem Biomol Eng 2012; 3:77-102. [DOI: 10.1146/annurev-chembioeng-061010-114239] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Elizabeth Schneider
- Department of Chemical and Biomolecular Engineering,
- UC Berkeley and UCSF Graduate Program in Bioengineering, University of California, Berkeley, California 94720; , , ,
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65
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Lipases and esterases from extremophiles: overview and case example of the production and purification of an esterase from Thermus thermophilus HB27. Methods Mol Biol 2012; 861:239-66. [PMID: 22426723 DOI: 10.1007/978-1-61779-600-5_15] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Extremophiles are organisms that have evolved to exist in a variety of extreme environments. They fall into a number of different classes that include thermophiles, halophiles, acidophiles, alkalophiles, psychrophiles, and barophiles (piezophiles). Extremophiles have the potential to produce uniquely valuable biocatalysts that function under conditions in which usually the enzymes of their nonextremophilic counterparts could not. Among novel enzymes isolated from extremophilic microorganisms, hydrolases, and particularly lipases and esterases are experiencing a growing demand. Lipases (EC 3.1.1.3) and esterases (EC 3.1.1.1) catalyze the cleavage of ester bounds in aqueous media and the reverse reaction in organic solvents. Both lipolytic enzymes have relevant applications in food, dairy, detergent, biofuel, and pharmaceutical industries. Here, we summarize the properties of lipases and esterases from the main extremophile groups: thermophiles and hyperthermophiles, psychrophiles, halophiles, alkalophiles/acidophiles, and solvent-resistant microorganisms.We report the biomass and lipolytic activity production by Thermus thermophilus HB27 in 5-L stirred-tank bioreactor at 70°C. Suitability of thermal spring water for culture media formulation is shown. In addition, a protocol to isolate and purify a cell-bound esterase from this microorganism is described.
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66
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Thermophilic esterase from the archaeon Archaeoglobus fulgidus physically immobilized on hydrophobic macroporous resin: A novel biocatalyst for polyester synthesis. BIOTECHNOL BIOPROC E 2011. [DOI: 10.1007/s12257-011-0260-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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67
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Atomi H, Sato T, Kanai T. Application of hyperthermophiles and their enzymes. Curr Opin Biotechnol 2011; 22:618-26. [DOI: 10.1016/j.copbio.2011.06.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 06/14/2011] [Accepted: 06/16/2011] [Indexed: 12/27/2022]
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68
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Yang Y, Yu Y, Zhang Y, Liu C, Shi W, Li Q. Lipase/esterase-catalyzed ring-opening polymerization: A green polyester synthesis technique. Process Biochem 2011. [DOI: 10.1016/j.procbio.2011.07.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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69
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Mei Y, Peng N, Zhao S, Hu Y, Wang H, Liang Y, She Q. Exceptional thermal stability and organic solvent tolerance of an esterase expressed from a thermophilic host. Appl Microbiol Biotechnol 2011; 93:1965-74. [PMID: 21847512 DOI: 10.1007/s00253-011-3504-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 07/07/2011] [Accepted: 07/19/2011] [Indexed: 11/29/2022]
Abstract
A protein expression system recently developed for the thermophilic crenarchaeon Sulfolobus islandicus was employed to produce recombinant protein for EstA, a thermophilic esterase encoded in the same organism. Large amounts of protein were readily obtained by an affinity protein purification, giving SisEstA. Upon Escherichia coli expression, only the thioredoxin-tagged EstA recombinant protein was soluble. The fusion protein was then purified, and removing the protein tag yielded EcSisEstA. Both forms of the thermophilic EstA enzyme were characterized. We found that SisEstA formed dimer exclusively in solution, whereas EcSisEstA appeared solely as monomer. The former exhibited a stronger resistance to organic solvents than the latter in general, having a much higher temperature optimum (90°C vs. 65°C). More strikingly, SisEstA exhibited a half-life that was more than 32-fold longer than that of EcSisEstA at 90°C. This indicated that thermophilic enzymes yielded from homologous expression should be better biocatalysts than those obtained from mesophilic expression.
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Affiliation(s)
- Yuxia Mei
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
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70
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Fuciños P, Pastrana L, Sanromán A, Longo M, Hermoso J, Rúa M. An esterase from Thermus thermophilus HB27 with hyper-thermoalkalophilic properties: Purification, characterisation and structural modelling. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.molcatb.2011.02.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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71
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Li Q, Li G, Yu S, Zhang Z, Ma F, Feng Y. Ring-opening polymerization of ɛ-caprolactone catalyzed by a novel thermophilic lipase from Fervidobacterium nodosum. Process Biochem 2011. [DOI: 10.1016/j.procbio.2010.08.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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72
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Guo J, Zheng X, Xu L, Liu Z, Xu K, Li S, Wen T, Liu S, Pang H. Characterization of a novel esterase Rv0045c from Mycobacterium tuberculosis. PLoS One 2010; 5. [PMID: 20957207 PMCID: PMC2948520 DOI: 10.1371/journal.pone.0013143] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 09/08/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND It was proposed that there are at least 250 enzymes in M. tuberculosis involved in lipid metabolism. Rv0045c was predicted to be a hydrolase by amino acid sequence similarity, although its precise biochemical characterization and function remained to be defined. METHODOLOGY/PRINCIPAL FINDINGS We expressed the Rv0045c protein to high levels in E. coli and purified the protein to high purity. We confirmed that the prepared protein was the Rv0045c protein by mass spectrometry analysis. Circular dichroism spectroscopy analysis showed that the protein possessed abundant β-sheet secondary structure, and confirmed that its conformation was stable in the range pH 6.0-10.0 and at temperatures ≤ 40 °C. Enzyme activity analysis indicated that the Rv0045c protein could efficiently hydrolyze short chain p-nitrophenyl esters (C₂-C₈), and its suitable substrate was p-nitrophenyl caproate (C₆) with optimal catalytic conditions of 39 °C and pH 8.0. CONCLUSIONS/SIGNIFICANCE Our results demonstrated that the Rv0045c protein is a novel esterase. These experiments will be helpful in understanding ester/lipid metabolism related to M. tuberculosis.
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Affiliation(s)
- Jiubiao Guo
- School of Medicine, Tsinghua University, Beijing, China
- Harbin Veterinary Research Institute, Chinese Academy of Agriculture, Harbin, China
| | | | - Lipeng Xu
- School of Medicine, Tsinghua University, Beijing, China
| | - Zhongyuan Liu
- School of Medicine, Tsinghua University, Beijing, China
| | - Kehui Xu
- School of Medicine, Tsinghua University, Beijing, China
| | - Shentao Li
- Department of Immunology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Tingyi Wen
- Department of Industrial Microbiology and Biotechnology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Siguo Liu
- Harbin Veterinary Research Institute, Chinese Academy of Agriculture, Harbin, China
- * E-mail: (SL); (HP)
| | - Hai Pang
- School of Medicine, Tsinghua University, Beijing, China
- * E-mail: (SL); (HP)
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Lv XY, Guo LZ, Song L, Fu Q, Zhao K, Li AX, Luo XL, Lu WD. Purification and characterization of a novel extracellular carboxylesterase from the moderately halophilic bacterium Thalassobacillus sp. strain DF-E4. ANN MICROBIOL 2010. [DOI: 10.1007/s13213-010-0135-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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74
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Barnard D, Casanueva A, Tuffin M, Cowan D. Extremophiles in biofuel synthesis. ENVIRONMENTAL TECHNOLOGY 2010; 31:871-888. [PMID: 20662378 DOI: 10.1080/09593331003710236] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The current global energy situation has demonstrated an urgent need for the development of alternative fuel sources to the continually diminishing fossil fuel reserves. Much research to address this issue focuses on the development of financially viable technologies for the production of biofuels. The current market for biofuels, defined as fuel products obtained from organic substrates, is dominated by bioethanol, biodiesel, biobutanol and biogas, relying on the use of substrates such as sugars, starch and oil crops, agricultural and animal wastes, and lignocellulosic biomass. This conversion from biomass to biofuel through microbial catalysis has gained much momentum as biotechnology has evolved to its current status. Extremophiles are a robust group of organisms producing stable enzymes, which are often capable of tolerating changes in environmental conditions such as pH and temperature. The potential application of such organisms and their enzymes in biotechnology is enormous, and a particular application is in biofuel production. In this review an overview of the different biofuels is given, covering those already produced commercially as well as those under development. The past and present trends in biofuel production are discussed, and future prospects for the industry are highlighted. The focus is on the current and future application of extremophilic organisms and enzymes in technologies to develop and improve the biotechnological production of biofuels.
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Affiliation(s)
- Desire Barnard
- Institute for Microbial Biotechnology and Metagenomics, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa
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A cold-adapted esterase of a novel marine isolate, Pseudoalteromonas arctica: gene cloning, enzyme purification and characterization. Extremophiles 2010; 14:273-85. [PMID: 20217440 DOI: 10.1007/s00792-010-0306-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 02/22/2010] [Indexed: 12/12/2022]
Abstract
A gene encoding an esterase (estO) was identified and sequenced from a gene library screen of the psychrotolerant bacterium Pseudoalteromonas arctica. Analysis of the 1,203 bp coding region revealed that the deduced peptide sequence is composed of 400 amino acids with a predicted molecular mass of 44.1 kDa. EstO contains a N-terminal esterase domain and an additional OsmC domain at the C-terminus (osmotically induced family of proteins). The highly conserved five-residue motif typical for all alpha/beta hydrolases (G x S x G) was detected from position 104 to 108 together with a putative catalytic triad consisting of Ser(106), Asp(196), and His(225). Sequence comparison showed that EstO exhibits 90% amino acid identity with hypothetical proteins containing similar esterase and OsmC domains but only around 10% identity to the amino acid sequences of known esterases. EstO variants with and without the OsmC domain were produced and purified as His-tag fusion proteins in E. coli. EstO displayed an optimum pH of 7.5 and optimum temperature of 25 degrees C with more than 50% retained activity at the freezing point of water. The thermostability of EstO (50% activity after 5 h at 40 degrees C) dramatically increased in the truncated variant (50% activity after 2.5 h at 90 degrees C). Furthermore, the esterase displays broad substrate specificity for esters of short-chain fatty acids (C(2)-C(8)).
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Characterization of a novel thermostable esterase from Thermus scotoductus SA-01: evidence of a new family of lipolytic esterases. Curr Microbiol 2009; 60:248-53. [PMID: 19967376 DOI: 10.1007/s00284-009-9533-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 10/27/2009] [Indexed: 01/26/2023]
Abstract
An esterase, designated EstTs1, was identified and characterized from a genomic library of Thermus scotoductus SA-01 (ATCC 700910). The library was screened in Escherichia coli for lipolytic activity on tributyrin agar plates. A 1.7-kb DNA fragment from a lipolytic positive clone was sequenced and two open reading frames (ORFs) were identified. A 774-bp ORF, designated EstTs1 with an estimated molecular mass of 28.6 kDa, and a 693-bp ORF, designated EstTs2 with an estimated molecular mass of 25.6 kDa, were identified. These two ORFs appear to form part of an operon. Sequence analysis showed that both proteins contained the G-X-S-X-G signature sequence motif present in most esterases and lipases. The deduced amino sequence of EstTs1 was found to display significant sequence identity with putative hydrolase proteins from both Thermus aquaticus Y51MC23 and Thermus thermophilus HB27. Similarly, EstTs2, also displayed significant homology to a second putative hydrolase protein present in the same two organisms. The cloning and characterization of these two ORFs from T. aquaticus Y51MC23 and T. thermophilus strain HB27 encoding putative hydrolase genes have not been reported. E. coli cells harbouring EstTs1 on a multicopy vector produced a clearing zone on tributyrin agar plates, whereas no enzymatic activity was observed for E. coli harbouring EstTs2 on a multicopy vector. EstTs1 displayed optimum activity at pH 7 and 80 degrees C with a half life of 48 h at 70 degrees C.
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