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Uenosono Y, Kawakami R, Matsumoto S, Yamaguchi Y. Construction of an experimental study and addition of adapter sequences using HiDi DNA polymerase for improving DNA normalization methods relevant to novel gene discovery. J Microbiol Methods 2023; 204:106631. [PMID: 36503828 DOI: 10.1016/j.mimet.2022.106631] [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: 09/14/2022] [Revised: 11/18/2022] [Accepted: 11/25/2022] [Indexed: 11/27/2022]
Abstract
Microorganisms in the environment can be distinguished into dominant and rare microbial species based on their genes. It is difficult to obtain genetic information derived from rare microbial species (rare genes) because of the differences in relative abundance. DNA normalization is an approach that is used to obtain genetic information derived from rare microbial species from an environmental sample. This method involves the addition of adapter sequences for the amplification, denaturation, and reassociation of the DNA fragments and single-stranded DNA (ssDNA)/double-stranded DNA (dsDNA) separation. In this method, the amount of a high-copy-number of DNA fragments and a low-copy-number of DNA fragments can be equalized. Improvements in this technique are expected to provide novel genetic information or genes in rare microbial species. However, few model experimental systems have been reported to validate the DNA normalization techniques. This study is aimed to improve the DNA normalization technique used to obtain genetic information of rare genes from rare microbial species. An experimental study was constructed with two antibiotic resistance genes, whose copy numbers differed up to a million-fold. Both genes were mixed and the mixture of DNA fragments, of high- and low-copy-number, containing these genes was normalized by separating ssDNA/dsDNA fragments using hydroxyapatite. Normalized DNA fragments were introduced into Escherichia coli and DNA normalization was evaluated by counting colonies. Moreover, we improved the method to amplify a low-copy-number of DNA fragments by the addition of adapter sequences to DNA fragments using HiDi DNA polymerase to increase the efficiency of DNA normalization. This normalization method was achieved with a 100,000-fold difference. These methods allowed for quantitative evaluation of the DNA normalization efficiency. The experimental data and methods obtained in this study are expected to improve the DNA normalization efficiency to obtain novel genetic information or genes.
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Affiliation(s)
- Yuya Uenosono
- Department of Materials Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami Chuo-ku, Kumamoto 860-8555, Japan
| | - Ryohei Kawakami
- Department of Materials Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami Chuo-ku, Kumamoto 860-8555, Japan
| | - Shogo Matsumoto
- Department of Materials Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami Chuo-ku, Kumamoto 860-8555, Japan
| | - Yoshihiro Yamaguchi
- Department of Materials Science and Applied Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami Chuo-ku, Kumamoto 860-8555, Japan; Environmental Safety Center, Kumamoto University, 2-40-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan.
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Metagenomic Approaches as a Tool to Unravel Promising Biocatalysts from Natural Resources: Soil and Water. Catalysts 2022. [DOI: 10.3390/catal12040385] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Natural resources are considered a promising source of microorganisms responsible for producing biocatalysts with great relevance in several industrial areas. However, a significant fraction of the environmental microorganisms remains unknown or unexploited due to the limitations associated with their cultivation in the laboratory through classical techniques. Metagenomics has emerged as an innovative and strategic approach to explore these unculturable microorganisms through the analysis of DNA extracted from environmental samples. In this review, a detailed discussion is presented on the application of metagenomics to unravel the biotechnological potential of natural resources for the discovery of promising biocatalysts. An extensive bibliographic survey was carried out between 2010 and 2021, covering diverse metagenomic studies using soil and/or water samples from different types and locations. The review comprises, for the first time, an overview of the worldwide metagenomic studies performed in soil and water and provides a complete and global vision of the enzyme diversity associated with each specific environment.
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Mtimka S, Pillay P, Rashamuse K, Gildenhuys S, Tsekoa TL. Functional screening of a soil metagenome for DNA endonucleases by acquired resistance to bacteriophage infection. Mol Biol Rep 2019; 47:353-361. [PMID: 31643043 DOI: 10.1007/s11033-019-05137-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/10/2019] [Indexed: 11/27/2022]
Abstract
Endonucleases play a crucial role as reagents in laboratory research and diagnostics. Here, metagenomics was used to functionally screen a fosmid library for endonucleases. A fosmid library was constructed using metagenomic DNA isolated from soil sampled from the unique environment of the Kogelberg Nature Reserve in the Western Cape of South Africa. The principle of acquired immunity against phage infection was used to develop a plate-based screening technique for the isolation of restriction endonucleases from the library. Using next-generation sequencing and bioinformatics tools, sequence data were generated and analysed, revealing 113 novel open reading frames (ORFs) encoding putative endonuclease genes and ORFs of unknown identity and function. One endonuclease designated Endo52 was selected from the putative endonuclease ORFs and was recombinantly produced in Escherichia coli Rosetta™ (DE3) pLysS. Endo52 was purified by immobilised metal affinity chromatography and yielded 0.437 g per litre of cultivation volume. Its enzyme activity was monitored by cleaving lambda DNA and pUC19 plasmid as substrates, and it demonstrated non-specific endonuclease activity. In addition to endonuclease-like genes, the screen identified several unknown genes. These could present new phage resistance mechanisms and are an opportunity for future investigations.
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Affiliation(s)
- Sibongile Mtimka
- Biomanufacturing Technologies, CSIR Future Production: Chemicals, P O Box 395, Pretoria, 0001, South Africa.,Department of Life & Consumer Sciences, College of Agriculture & Environmental Sciences, University of South Africa, Florida Campus (The Science Hub), Florida, P O Box 392, Johannesburg, South Africa
| | - Priyen Pillay
- Biomanufacturing Technologies, CSIR Future Production: Chemicals, P O Box 395, Pretoria, 0001, South Africa
| | - Konanani Rashamuse
- Biomanufacturing Technologies, CSIR Future Production: Chemicals, P O Box 395, Pretoria, 0001, South Africa
| | - Samantha Gildenhuys
- Department of Life & Consumer Sciences, College of Agriculture & Environmental Sciences, University of South Africa, Florida Campus (The Science Hub), Florida, P O Box 392, Johannesburg, South Africa
| | - Tsepo L Tsekoa
- Biomanufacturing Technologies, CSIR Future Production: Chemicals, P O Box 395, Pretoria, 0001, South Africa.
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Istvan P, Souza AA, Garay AV, Dos Santos DFK, de Oliveira GM, Santana RH, Lopes FAC, de Freitas SM, Barbosa JARG, Krüger RH. Structural and functional characterization of a novel lipolytic enzyme from a Brazilian Cerrado soil metagenomic library. Biotechnol Lett 2018; 40:1395-1406. [PMID: 30062528 DOI: 10.1007/s10529-018-2598-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 07/25/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To isolate putative lipase enzymes by screening a Cerrado soil metagenomic library with novel features. RESULTS Of 6720 clones evaluated, Clone W (10,000 bp) presented lipolytic activity and four predicted coding sequences, one of them LipW. Characterization of a predicted esterase/lipase, LipW, showed 28% sequence identity with an arylesterase from Pseudomonas fluorescens (pdb|3HEA) from protein database (PDB). Phylogenetic analysis showed LipW clustered with family V lipases; however, LipW was clustered in different subclade belonged to family V, suggesting a different subgroup of family V. In addition, LipW presented a difference in family V GH motif, a glycine replaced by a serine in GH motif. Estimated molecular weight and stokes radius values of LipW were 29,338.67-29,411.98 Da and 2.58-2.83 nm, respectively. Optimal enzyme activity was observed at pH 9.0-9.5 and at 40 °C. Circular dichroism analysis estimated secondary structures percentages as approximately 45% α-helix and 15% β-sheet, consistent with the 3D structure predicted by homology. CONCLUSION Our results demonstrate the isolation of novel family V lipolytic enzyme with biotechnological applications from a metagenomic library.
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Affiliation(s)
- Paula Istvan
- Laboratório de Enzimologia, Departamento de Biologia Celular, Instituto Central de Ciências Sul, Universidade de Brasília - UnB, Brasília, DF, 700910-900, Brazil
| | - Amanda Araújo Souza
- Laboratório de Biofísica, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, Brazil
| | - Aisel Valle Garay
- Laboratório de Biofísica, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, Brazil
| | - Debora Farage Knupp Dos Santos
- Laboratório de Enzimologia, Departamento de Biologia Celular, Instituto Central de Ciências Sul, Universidade de Brasília - UnB, Brasília, DF, 700910-900, Brazil
| | - Gideane Mendes de Oliveira
- Laboratório de Biofísica, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, Brazil
| | | | - Fabyano Alvares Cardoso Lopes
- Laboratório de Enzimologia, Departamento de Biologia Celular, Instituto Central de Ciências Sul, Universidade de Brasília - UnB, Brasília, DF, 700910-900, Brazil
| | - Sonia Maria de Freitas
- Laboratório de Biofísica, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF, Brazil
| | | | - Ricardo Henrique Krüger
- Laboratório de Enzimologia, Departamento de Biologia Celular, Instituto Central de Ciências Sul, Universidade de Brasília - UnB, Brasília, DF, 700910-900, Brazil.
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Wang S, Gao X, Gao Y, Li Y, Cao M, Xi Z, Zhao L, Feng Z. Tetracycline Resistance Genes Identified from Distinct Soil Environments in China by Functional Metagenomics. Front Microbiol 2017; 8:1406. [PMID: 28790997 PMCID: PMC5522880 DOI: 10.3389/fmicb.2017.01406] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/11/2017] [Indexed: 12/30/2022] Open
Abstract
Soil microbiota represents one of the ancient evolutionary origins of antibiotic resistance and has been increasingly recognized as a potentially vast unstudied reservoir of resistance genes with possibilities to exchange with pathogens. Tetracycline resistance is one of the most abundant antibiotic resistances that may transfer among clinical and commensal microorganisms. To investigate tetracycline resistance genes from soil bacteria in different habitats, we performed functional analysis of three metagenomic libraries derived from soil samples collected from Yunnan, Sichuan, and Tibet, respectively, in China. We found efflux transporter genes form all the libraries, including 21 major facilitator superfamily efflux pump genes and one multidrug and toxic compound extrusion (MATE) transporter gene. Interestingly, we also identified two tetracycline destructase genes, belonging to a newly described family of tetracycline-inactivating enzymes that scarcely observed in clinical pathogens, from the Tibet library. The inactivation activity of the putative enzyme was confirmed in vitro by biochemical analysis. Our results indicated that efflux pumps distributed predominantly across habitats. Meanwhile, the mechanism of enzymatic inactivation for tetracycline resistance should not be neglected and merits further investigation.
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Affiliation(s)
- Shaochen Wang
- College of Food Science and Technology, Nanjing Agricultural UniversityNanjing, China
| | - Xia Gao
- College of Food Science and Technology, Nanjing Agricultural UniversityNanjing, China
| | - Yuejiao Gao
- College of Food Science and Technology, Nanjing Agricultural UniversityNanjing, China
| | - Yanqing Li
- College of Food Science and Technology, Nanjing Agricultural UniversityNanjing, China
| | - Mingming Cao
- College of Food Science and Technology, Nanjing Agricultural UniversityNanjing, China
| | - Zhenhua Xi
- Institute of Tibetan Plateau Research, Chinese Academy of SciencesBeijing, China
| | - Lixing Zhao
- Yunnan Institute of Microbiology, Yunnan UniversityKunming, China
| | - Zhiyang Feng
- College of Food Science and Technology, Nanjing Agricultural UniversityNanjing, China
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Müller CA, Obermeier MM, Berg G. Bioprospecting plant-associated microbiomes. J Biotechnol 2016; 235:171-80. [DOI: 10.1016/j.jbiotec.2016.03.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/17/2016] [Accepted: 03/21/2016] [Indexed: 10/22/2022]
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