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Mongui A, Lozano GL, Handelsman J, Restrepo S, Junca H. Design and validation of a transposon that promotes expression of genes in episomal DNA. J Biotechnol 2020; 310:1-5. [PMID: 31954761 DOI: 10.1016/j.jbiotec.2020.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 01/15/2020] [Indexed: 01/20/2023]
Abstract
Functional metagenomics, or the cloning and expression of DNA isolated directly from environmental samples, represents a source of novel compounds with biotechnological potential. However, attempts to identify such compounds in metagenomic libraries are generally inefficient in part due to lack of expression of heterologous DNA. In this research, the TnC_T7 transposon was developed to supply transcriptional machinery during functional analysis of metagenomic libraries. TnC_T7 contains bidirectional T7 promoters, the gene encoding the T7 RNA polymerase (T7RNAP), and a kanamycin resistance gene. The T7 RNA polymerase gene is regulated by the inducible arabinose promoter (PBAD), thereby facilitating inducible expression of genes adjacent to the randomly integrating transposon. The high processivity of T7RNAP should make this tool particularly useful for obtaining gene expression in long inserts. TnC_T7 functionality was validated by conducting in vitro transposition of pKR-C12 or fosmid pF076_GFPmut3*, carrying metagenomic DNA from soil. We identified transposon insertions that enhanced GFP expression in both vectors, including insertions in which the promoter delivered by the transposon was located as far as 8.7 kb from the GFP gene, indicating the power of the high processivity of the T7 polymerase. The results gathered in this research demonstrate the potential of TnC_T7 to enhance gene expression in functional metagenomic studies.
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Affiliation(s)
- Alvaro Mongui
- Molecular Biotechnology, Corporación CorpoGen, Bogotá, Colombia; Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia.
| | - Gabriel L Lozano
- Wisconsin Institute for Discovery and Department of Plant Pathology, University of Wisconsin, Madison, WI, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Jo Handelsman
- Wisconsin Institute for Discovery and Department of Plant Pathology, University of Wisconsin, Madison, WI, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Silvia Restrepo
- Laboratory of Mycology and Plant Diseases, Universidad de los Andes, Bogotá, Colombia
| | - Howard Junca
- RG Microbial Ecology: Metabolism, Genomics & Evolution, Microbiomas Foundation, Chía, Colombia
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Calderon D, Peña L, Suarez A, Villamil C, Ramirez-Rojas A, Anzola JM, García-Betancur JC, Cepeda ML, Uribe D, Del Portillo P, Mongui A. Recovery and functional validation of hidden soil enzymes in metagenomic libraries. Microbiologyopen 2019; 8:e00572. [PMID: 30851083 PMCID: PMC6460280 DOI: 10.1002/mbo3.572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/01/2017] [Accepted: 11/09/2017] [Indexed: 11/10/2022] Open
Abstract
The vast microbial diversity on the planet represents an invaluable source for identifying novel activities with potential industrial and therapeutic application. In this regard, metagenomics has emerged as a group of strategies that have significantly facilitated the analysis of DNA from multiple environments and has expanded the limits of known microbial diversity. However, the functional characterization of enzymes, metabolites, and products encoded by diverse microbial genomes is limited by the inefficient heterologous expression of foreign genes. We have implemented a pipeline that combines NGS and Sanger sequencing as a way to identify fosmids within metagenomic libraries. This strategy facilitated the identification of putative proteins, subcloning of targeted genes and preliminary characterization of selected proteins. Overall, the in silico approach followed by the experimental validation allowed us to efficiently recover the activity of previously hidden enzymes derived from agricultural soil samples. Therefore, the methodology workflow described herein can be applied to recover activities encoded by environmental DNA from multiple sources.
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Affiliation(s)
- Dayana Calderon
- Molecular Biotechnology Research Group, Corporación CorpoGen, Bogotá, Colombia
| | - Luis Peña
- Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Friedrich-Schiller Universität, Jena, Germany
| | - Angélica Suarez
- Molecular Biotechnology Research Group, Corporación CorpoGen, Bogotá, Colombia
| | - Carolina Villamil
- Molecular Biotechnology Research Group, Corporación CorpoGen, Bogotá, Colombia
| | - Adan Ramirez-Rojas
- Molecular Biotechnology Research Group, Corporación CorpoGen, Bogotá, Colombia
| | - Juan M Anzola
- Computational Biology, Corporación CorpoGen, Bogotá, Colombia
| | | | - Martha L Cepeda
- Molecular Biotechnology Research Group, Corporación CorpoGen, Bogotá, Colombia
| | - Daniel Uribe
- Biotechnology Institute, Universidad Nacional de Colombia, Bogotá, Colombia
| | | | - Alvaro Mongui
- Molecular Biotechnology Research Group, Corporación CorpoGen, Bogotá, Colombia.,Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia
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Kim YJ, Kim H, Kim SH, Rha E, Choi SL, Yeom SJ, Kim HS, Lee SG. Improved metagenome screening efficiency by random insertion of T7 promoters. J Biotechnol 2016; 230:47-53. [PMID: 27239964 DOI: 10.1016/j.jbiotec.2016.05.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/04/2016] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
Abstract
Metagenomes constitute a major source for the identification of novel enzymes for industrial applications. However, current functional screening methods are hindered by the limited transcription efficiency of foreign metagenomic genes. To overcome this constraint, we introduced the 'Enforced Transcription' technique, which involves the random insertion of the bi-directional T7 promoter into a metagenomic fosmid library. Then the effect of enforced transcription was quantitatively assessed by screening for metagenomic lipolytic genes encoding enzymes whose catalytic activity forms halos on tributyrin agar plates. The metagenomic library containing the enforced transcription system yielded a significantly increased number of screening hits with lipolytic activity compared to the library without random T7 promoter insertions. Additional sequence analysis revealed that the hits from the enforced transcription library had greater genetic diversity than those from the original metagenome library. Enhancing heterologous expression using the T7 promoter should enable the identification of greater numbers of diverse novel biocatalysts from the metagenome than possible using conventional metagenome screening approaches.
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Affiliation(s)
- Yu Jung Kim
- Department of BiologicalSciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea; Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea
| | - Haseong Kim
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea
| | - Seo Hyeon Kim
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea
| | - Eugene Rha
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea
| | - Su-Lim Choi
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea
| | - Soo-Jin Yeom
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea
| | - Hak-Sung Kim
- Department of BiologicalSciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
| | - Seung-Goo Lee
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea; Biosystems & Bioengineering, University of Science & Technology (UST), Daejeon 34113, South Korea.
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Ongley SE, Bian X, Neilan BA, Müller R. Recent advances in the heterologous expression of microbial natural product biosynthetic pathways. Nat Prod Rep 2013; 30:1121-38. [PMID: 23832108 DOI: 10.1039/c3np70034h] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The heterologous expression of microbial natural product biosynthetic pathways coupled with advanced DNA engineering enables optimisation of product yields, functional elucidation of cryptic gene clusters, and generation of novel derivatives. This review summarises the recent advances in cloning and maintenance of natural product biosynthetic gene clusters for heterologous expression and the efforts fundamental for discovering novel natural products in the post-genomics era, with a focus on polyketide synthases (PKSs) and non-ribosomal polypeptide synthetases (NRPS).
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Affiliation(s)
- Sarah E Ongley
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, Australia
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Troeschel SC, Drepper T, Leggewie C, Streit WR, Jaeger KE. Novel tools for the functional expression of metagenomic DNA. Methods Mol Biol 2011; 668:117-39. [PMID: 20830560 DOI: 10.1007/978-1-60761-823-2_8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The functional expression of environmental genes in a particular host bacterium is hampered by various limitations including inefficient transcription of target genes as well as improper assembly of the corresponding enzymes. Therefore, the identification of novel enzymes from metagenomic libraries by activity-based screening requires efficient expression and screening systems. In the following chapter, we present two novel tools to improve the functional expression of metagenomic genes. (1) Comparative screenings of metagenomic libraries demonstrated that different enzymes were detected when phylogenetically distinct expression host strains were used. Thus, we have developed a strategy, which comprises library construction using a shuttle vector that allows comparative expression and screening of metagenomic DNA in Escherichia coli, Pseudomonas putida, and Bacillus subtilis. (2) Expression studies have revealed that functional expression of environmental genes in heterologous expression hosts is often limited by insufficient promoter recognition. Therefore, a method is described allowing to enhance the expression capacity of E. coli by using the transposon MuExpress. This recombinant transposon is able to insert randomly into environmental DNA fragments thereby facilitating gene expression from its two inducible promoters.
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Affiliation(s)
- Sonja Christina Troeschel
- Research Centre Juelich, Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Juelich, Germany
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Lussier FX, Chambenoit O, Côté A, Hupé JF, Denis F, Juteau P, Beaudet R, Shareck F. Construction and functional screening of a metagenomic library using a T7 RNA polymerase-based expression cosmid vector. J Ind Microbiol Biotechnol 2010; 38:1321-8. [DOI: 10.1007/s10295-010-0915-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 11/12/2010] [Indexed: 11/24/2022]
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Jach G, Soezer N, Schullehner K, Lalla B, Welters P, Mueller A. Phytomining of plant enzymes for biotechnological use of fats and oils. EUR J LIPID SCI TECH 2010. [DOI: 10.1002/ejlt.200900100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Recent trends in industrial microbiology. Curr Opin Microbiol 2008; 11:240-8. [DOI: 10.1016/j.mib.2008.04.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 04/21/2008] [Accepted: 04/28/2008] [Indexed: 02/04/2023]
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Mullany P, Hunter S, Allan E. Chapter 4 Metagenomics of Dental Biofilms. ADVANCES IN APPLIED MICROBIOLOGY 2008; 64:125-36. [DOI: 10.1016/s0065-2164(08)00404-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Firkins JL, Karnati SKR, Yu Z. Linking rumen function to animal response by application of metagenomics techniques. ACTA ACUST UNITED AC 2008. [DOI: 10.1071/ea08028] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Metagenomics techniques applied to the rumen microbiota have demonstrated tremendous diversity originally among populations of bacteria and, more recently, among the methanogenic archaea, including those associated with protozoa. Although with some potential limitations, cluster analyses of sequences recovered from clone libraries have revealed differences in populations among animals fed forage v. grain, including amylolytic ruminococci and novel groups of clostridia adhering to the rumen particulates. Rapid profiling procedures, such as denaturing gradient gel electrophoresis (DGGE), can be used to infer likely differences in community structure of bacteria and archaea among numerous replicates of animals and times after feeding diets that are more representative of intense ruminant animal production. Metagenomics procedures also are being applied to issues related to ruminal output of fatty acid isomers influencing milk fat composition and consumer acceptance, the environmental impact of nitrogen in animal waste and methane emissions, and future potential approaches to improve ruminal fibre digestibility. If varying concentrations of ruminal metabolites and fluxes quantified from microbial processes can be combined with results from metagenomics applied to rumen microbiota, then we should reduce the unexplained variability in models in which the prediction of nutrient supply to the intestine is synchronised with nutritional guidelines for more efficient feed conversion by ruminants.
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Abstract
Metagenomics--the application of the genomics suit of technologies to uncultivated microorganisms--is coming of age. Sophisticated technologies are being developed and adapted to this promising genetic resource to make increasing use of the seemingly boundless molecular and functional diversity. Particular progress has been made in the areas of randomly proliferating limited-source DNA, massively parallel sequencing without cloning, isolating specific target sequences from highly complex template mixtures, high-throughput assay systems targeting metabolic pathways, artificial transcriptional regulators activating reporter genes to indicate enzymatic substrate conversion and cDNA cloning from extracted mRNA to directly clone actively expressed genes from a microbial consortium. However, challenges still lie ahead. Most prominently, the efficient heterologous expression of a plethora of potentially interesting enzymes from unknown source organisms is not readily achieved.
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Drepper T, Eggert T, Hummel W, Leggewie C, Pohl M, Rosenau F, Wilhelm S, Jaeger KE. Novel biocatalysts for white biotechnology. Biotechnol J 2006; 1:777-86. [PMID: 16927261 DOI: 10.1002/biot.200600059] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
White Biotechnology uses microorganisms and enzymes to manufacture a large variety of chemical products. Therefore, the demand for new and useful biocatalysts is steadily and rapidly increasing. We have developed methods for the isolation of new enzyme genes, constructed novel expression systems, and optimized existing enzymes for biotechnological applications by methods of directed evolution. Furthermore, we have isolated and characterized biocatalysts relevant for the preparation of enantiopure compounds.
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Affiliation(s)
- Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Research Center Jülich, Jülich, Germany
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