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Sutaoney P, Rai SN, Sinha S, Choudhary R, Gupta AK, Singh SK, Banerjee P. Current perspective in research and industrial applications of microbial cellulases. Int J Biol Macromol 2024; 264:130639. [PMID: 38453122 DOI: 10.1016/j.ijbiomac.2024.130639] [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: 08/29/2023] [Revised: 01/12/2024] [Accepted: 03/03/2024] [Indexed: 03/09/2024]
Abstract
The natural interactions between various bacteria, fungi, and other cellulolytic microorganisms destroy lignocellulosic polymers. The efficacy of this process is determined by the combined action of three main enzymes: endoglucanases, exo-glucanases, and β-glucosidase. The enzyme attacks the polymeric structure's β-1,4-linkages during the cellulose breakdown reaction. This mechanism is crucial for the environment as it recycles cellulose in the biosphere. However, there are problems with enzymatic cellulose breakdown, including complex cellulase structure, insufficient degradation efficacy, high production costs, and post-translational alterations, many of which are closely related to certain unidentified cellulase properties. These issues impede the practical use of cellulases. A developing area of research is the application of this similar paradigm for industrial objectives. Cellulase enzyme exhibits greater promise in many critical industries, including biofuel manufacture, textile smoothing and finishing, paper and pulp manufacturing, and farming. However, the study on cellulolytic enzymes must move forward in various directions, including increasing the activity of cellulase as well as designing peptides to give biocatalysts their desired attributes. This manuscript includes an overview of current research on different sources of cellulases, their production, and biochemical characterization.
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Affiliation(s)
- Priya Sutaoney
- Present address-Department of Microbiology, Kalinga University, Raipur 492101, Chhattisgarh, India; Microbiology Laboratory, School of Studies in Life Science, Pt. Ravishankar Shukla University, Raipur 492010, Chhattisgarh, India
| | - Sachchida Nand Rai
- Centre of Experimental Medicine and Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Sakshi Sinha
- Present address-Department of Microbiology, Kalinga University, Raipur 492101, Chhattisgarh, India
| | - Rachana Choudhary
- Department of Microbiology, Shri Shankaracharya Mahavidyalaya, Junwani, Durg 490005, Chhattisgarh, India
| | - A K Gupta
- Microbiology Laboratory, School of Studies in Life Science, Pt. Ravishankar Shukla University, Raipur 492010, Chhattisgarh, India
| | - Santosh Kumar Singh
- Centre of Experimental Medicine and Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India.
| | - Paromita Banerjee
- Department of Cardiology, All India Institute of Medical Sciences, Rishikesh, 249203, Uttarakhand, India.
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Escudeiro P, Henry CS, Dias RP. Functional characterization of prokaryotic dark matter: the road so far and what lies ahead. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100159. [PMID: 36561390 PMCID: PMC9764257 DOI: 10.1016/j.crmicr.2022.100159] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 07/18/2022] [Accepted: 08/05/2022] [Indexed: 12/25/2022] Open
Abstract
Eight-hundred thousand to one trillion prokaryotic species may inhabit our planet. Yet, fewer than two-hundred thousand prokaryotic species have been described. This uncharted fraction of microbial diversity, and its undisclosed coding potential, is known as the "microbial dark matter" (MDM). Next-generation sequencing has allowed to collect a massive amount of genome sequence data, leading to unprecedented advances in the field of genomics. Still, harnessing new functional information from the genomes of uncultured prokaryotes is often limited by standard classification methods. These methods often rely on sequence similarity searches against reference genomes from cultured species. This hinders the discovery of unique genetic elements that are missing from the cultivated realm. It also contributes to the accumulation of prokaryotic gene products of unknown function among public sequence data repositories, highlighting the need for new approaches for sequencing data analysis and classification. Increasing evidence indicates that these proteins of unknown function might be a treasure trove of biotechnological potential. Here, we outline the challenges, opportunities, and the potential hidden within the functional dark matter (FDM) of prokaryotes. We also discuss the pitfalls surrounding molecular and computational approaches currently used to probe these uncharted waters, and discuss future opportunities for research and applications.
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Affiliation(s)
- Pedro Escudeiro
- BioISI - Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisboa 1749-016, Portugal
| | - Christopher S. Henry
- Argonne National Laboratory, Lemont, Illinois, USA
- University of Chicago, Chicago, Illinois, USA
| | - Ricardo P.M. Dias
- BioISI - Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisboa 1749-016, Portugal
- iXLab - Innovation for National Biological Resilience, Faculdade de Ciências, Universidade de Lisboa, Lisboa 1749-016, Portugal
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Hassan S, Sabreena, Khurshid Z, Bhat SA, Kumar V, Ameen F, Ganai BA. Marine Bacteria and Omic Approaches: A Novel and Potential Repository for Bioremediation Assessment. J Appl Microbiol 2022; 133:2299-2313. [PMID: 35818751 DOI: 10.1111/jam.15711] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/15/2022] [Accepted: 07/01/2022] [Indexed: 10/17/2022]
Abstract
Marine environments accommodating diverse assortments of life constitute a great pool of differentiated natural resources. The cumulative need to remedy unpropitious effects of anthropogenic activities on estuaries, and coastal marine ecosystems has propelled the development of effective bioremediation strategies. Marine bacteria producing biosurfactants are promising agents for bio-remediating oil pollution in marine environments, making them prospective candidates for enhancing oil recovery. Molecular omics technologies are considered an emerging field of research in ecological and diversity assessment owing to their utility in environmental surveillance and bioremediation of polluted sites. A thorough literature review was undertaken to understand the applicability of different omic techniques employed for bioremediation assessment using marine bacteria. This review further establishes that for bioremediation of environmental pollutants (i.e., heavy metals, hydrocarbons, xenobiotic and numerous recalcitrant compounds), organisms isolated from marine environments can be better utilized for their removal. The literature survey shows that omics approaches can provide exemplary knowledge about microbial communities and their role in the bioremediation of environmental pollutants. This review centres on applications of marine bacteria in enhanced bioremediation, utilizing the omics approaches that can be a vital biological contrivance in environmental monitoring to tackle environmental degradation. The paper aims to identify the gaps in investigations involving marine bacteria to help researchers, ecologists, and decision-makers to develop a holistic understanding regarding their utility in bioremediation assessment.
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Affiliation(s)
- Shahnawaz Hassan
- Department of Environmental Science, University of Kashmir, India
| | - Sabreena
- Department of Environmental Science, University of Kashmir, India
| | | | | | - Vineet Kumar
- Department of Botany, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh-495009, India
| | - Fuad Ameen
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
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Discovery and Biotechnological Exploitation of Glycoside-Phosphorylases. Int J Mol Sci 2022; 23:ijms23063043. [PMID: 35328479 PMCID: PMC8950772 DOI: 10.3390/ijms23063043] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
Among carbohydrate active enzymes, glycoside phosphorylases (GPs) are valuable catalysts for white biotechnologies, due to their exquisite capacity to efficiently re-modulate oligo- and poly-saccharides, without the need for costly activated sugars as substrates. The reversibility of the phosphorolysis reaction, indeed, makes them attractive tools for glycodiversification. However, discovery of new GP functions is hindered by the difficulty in identifying them in sequence databases, and, rather, relies on extensive and tedious biochemical characterization studies. Nevertheless, recent advances in automated tools have led to major improvements in GP mining, activity predictions, and functional screening. Implementation of GPs into innovative in vitro and in cellulo bioproduction strategies has also made substantial advances. Herein, we propose to discuss the latest developments in the strategies employed to efficiently discover GPs and make the best use of their exceptional catalytic properties for glycoside bioproduction.
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Ajeje SB, Hu Y, Song G, Peter SB, Afful RG, Sun F, Asadollahi MA, Amiri H, Abdulkhani A, Sun H. Thermostable Cellulases / Xylanases From Thermophilic and Hyperthermophilic Microorganisms: Current Perspective. Front Bioeng Biotechnol 2021; 9:794304. [PMID: 34976981 PMCID: PMC8715034 DOI: 10.3389/fbioe.2021.794304] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/02/2021] [Indexed: 12/13/2022] Open
Abstract
The bioconversion of lignocellulose into monosaccharides is critical for ensuring the continual manufacturing of biofuels and value-added bioproducts. Enzymatic degradation, which has a high yield, low energy consumption, and enhanced selectivity, could be the most efficient and environmentally friendly technique for converting complex lignocellulose polymers to fermentable monosaccharides, and it is expected to make cellulases and xylanases the most demanded industrial enzymes. The widespread nature of thermophilic microorganisms allows them to proliferate on a variety of substrates and release substantial quantities of cellulases and xylanases, which makes them a great source of thermostable enzymes. The most significant breakthrough of lignocellulolytic enzymes lies in lignocellulose-deconstruction by enzymatic depolymerization of holocellulose into simple monosaccharides. However, commercially valuable thermostable cellulases and xylanases are challenging to produce in high enough quantities. Thus, the present review aims at giving an overview of the most recent thermostable cellulases and xylanases isolated from thermophilic and hyperthermophilic microbes. The emphasis is on recent advancements in manufacturing these enzymes in other mesophilic host and enhancement of catalytic activity as well as thermostability of thermophilic cellulases and xylanases, using genetic engineering as a promising and efficient technology for its economic production. Additionally, the biotechnological applications of thermostable cellulases and xylanases of thermophiles were also discussed.
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Affiliation(s)
- Samaila Boyi Ajeje
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yun Hu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Guojie Song
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Sunday Bulus Peter
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Richmond Godwin Afful
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Mohammad Ali Asadollahi
- Department of Biotechnology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - Hamid Amiri
- Department of Biotechnology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - Ali Abdulkhani
- Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | - Haiyan Sun
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
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Mining of a novel esterase (est3S) gene from a cow rumen metagenomic library with organosphosphorus insecticides degrading capability: Catalytic insights by site directed mutations, docking, and molecular dynamic simulations. Int J Biol Macromol 2021; 190:441-455. [PMID: 34506858 DOI: 10.1016/j.ijbiomac.2021.08.224] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/29/2021] [Accepted: 08/31/2021] [Indexed: 11/22/2022]
Abstract
A novel esterase (est3S) gene, 1026 bp in size, was cloned from a metagenomic library made of uncultured microorganisms from the contents of cow rumen. The esterolytic enzyme (Est3S) is composed of 342 amino acids and shows the highest identity with EstGK1 (71.7%) and EstZ3 (63.78%) esterases from the uncultured bacterium. The Est3S did not cluster in any up-to-date classes (I to XVIII) of esterase and lipase. Est3S protein molecular weight was determined to be 38 kDa by gel electrophoresis and showed optimum activity at pH 7.0 and 40 °C and is partially resistant to organic solvents. Est3S activity was enhanced by K+, Na+, Mg2+, and Ca2+ and its highest activity was observed toward the short-chain p-nitrophenyl esters. Additionally, Est3S can degrade chlorpyrifos (CP) and methyl parathion (70% to 80%) in an hour. A mutated Est3S (Ser132-Ala132) did not show any activity toward CP and ester substrates. Notably, the GHS132QG motif is superimposed with the homolog esterase and cutinase-like esterase. Therefore, Ser132 is the critical amino acid like other esterases. The Est3S is relatively stable with ester compounds, and the methyl parathion complex was confirmed by molecular dynamics simulation. NOVELTY STATEMENT: A novel esterase gene (est3S) expressing esters and organophosphorus insecticide degradation traits was isolated from the uncultured bacterium in the contents of cow rumen. The Est3S protein did not cluster in any up-to-date classes (I to XVIII) of esterase/lipase proteins. Est3S was stable with the ligands up to 100 ns during the molecular dynamic simulations.
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Bardou P, Laguerre S, Maman Haddad S, Legoueix Rodriguez S, Laville E, Dumon C, Potocki-Veronese G, Klopp C. MINTIA: a metagenomic INserT integrated assembly and annotation tool. PeerJ 2021; 9:e11885. [PMID: 34692239 PMCID: PMC8483015 DOI: 10.7717/peerj.11885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 07/09/2021] [Indexed: 11/29/2022] Open
Abstract
The earth harbors trillions of bacterial species adapted to very diverse ecosystems thanks to specific metabolic function acquisition. Most of the genes responsible for these functions belong to uncultured bacteria and are still to be discovered. Functional metagenomics based on activity screening is a classical way to retrieve these genes from microbiomes. This approach is based on the insertion of large metagenomic DNA fragments into a vector and transformation of a host to express heterologous genes. Metagenomic libraries are then screened for activities of interest, and the metagenomic DNA inserts of active clones are extracted to be sequenced and analysed to identify genes that are responsible for the detected activity. Hundreds of metagenomics sequences found using this strategy have already been published in public databases. Here we present the MINTIA software package enabling biologists to easily generate and analyze large metagenomic sequence sets, retrieved after activity-based screening. It filters reads, performs assembly, removes cloning vector, annotates open reading frames and generates user friendly reports as well as files ready for submission to international sequence repositories. The software package can be downloaded from https://github.com/Bios4Biol/MINTIA.
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Affiliation(s)
- Philippe Bardou
- Sigenae, GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet Tolosan, France
| | | | - Sarah Maman Haddad
- Sigenae, GenPhySE, Université de Toulouse, INRAE, ENVT, Castanet Tolosan, France
| | | | | | - Claire Dumon
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | | | - Christophe Klopp
- Sigenae, Genotoul Bioinfo, MIAT UR875, INRAE, Castanet Tolosan, France
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Two-step functional screen on multiple proteinaceous substrates reveals temperature-robust proteases with a broad-substrate range. Appl Microbiol Biotechnol 2021; 105:3195-3209. [PMID: 33770243 PMCID: PMC8053189 DOI: 10.1007/s00253-021-11235-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 02/15/2021] [Accepted: 03/14/2021] [Indexed: 01/21/2023]
Abstract
Abstract To support the bio-based industry in development of environment-friendly processes and products, an optimal toolbox of biocatalysts is key. Although functional screen of (meta)genomic libraries may potentially contribute to identifying new enzymes, the discovery of new enzymes meeting industry compliance demands is still challenging. This is particularly noticeable in the case of proteases, for which the reports of metagenome-derived proteases with industrial applicability are surprisingly limited. Indeed, proteolytic clones have been typically assessed by its sole activity on casein or skim milk and limited to mild screening conditions. Here, we demonstrate the use of six industry-relevant animal and plant by-products, namely bone, feather, blood meals, gelatin, gluten, and zein, as complementary substrates in functional screens and show the utility of temperature as a screening parameter to potentially discover new broad-substrate range and robust proteases for the biorefinery industry. By targeting 340,000 clones from two libraries of pooled isolates of mesophilic and thermophilic marine bacteria and two libraries of microbial communities inhabiting marine environments, we identified proteases in four of eleven selected clones that showed activity against all substrates herein tested after prolonged incubation at 55 °C. Following sequencing, in silico analysis and recombinant expression in Escherichia coli, one functional protease, 58% identical at sequence level to previously reported homologs, was found to readily hydrolyze highly insoluble zein at temperatures up to 50 °C and pH 9–11. It is derived from a bacterial group whose ability to degrade zein was unknown. This study reports a two-step screen resulting in identification of a new marine metagenome-derived protease with zein-hydrolytic properties at common biomass processing temperatures that could be useful for the modern biorefinery industry. Key points • A two-step multi-substrate strategy for discovery of robust proteases. • Feasible approach for shortening enzyme optimization to industrial demands. • A new temperature-tolerant protease efficiently hydrolyzes insoluble zein. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-021-11235-9.
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Souto BDM, de Araújo ACB, Hamann PRV, Bastos ADR, Cunha IDS, Peixoto J, Kruger RH, Noronha EF, Quirino BF. Functional screening of a Caatinga goat (Capra hircus) rumen metagenomic library reveals a novel GH3 β-xylosidase. PLoS One 2021; 16:e0245118. [PMID: 33449963 PMCID: PMC7810302 DOI: 10.1371/journal.pone.0245118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 12/23/2020] [Indexed: 11/18/2022] Open
Abstract
Functional screening of metagenomic libraries is an effective approach for identification of novel enzymes. A Caatinga biome goat rumen metagenomic library was screened using esculin as a substrate, and a gene from an unknown bacterium encoding a novel GH3 enzyme, BGL11, was identified. None of the BGL11 closely related genes have been previously characterized. Recombinant BGL11 was obtained and kinetically characterized. Substrate specificity of the purified protein was assessed using seven synthetic aryl substrates. Activity towards nitrophenyl-β-D-glucopyranoside (pNPG), 4-nitrophenyl-β-D-xylopyranoside (pNPX) and 4-nitrophenyl-β-D-cellobioside (pNPC) suggested that BGL11 is a multifunctional enzyme with β-glucosidase, β-xylosidase, and cellobiohydrolase activities. However, further testing with five natural substrates revealed that, although BGL11 has multiple substrate specificity, it is most active towards xylobiose. Thus, in its native goat rumen environment, BGL11 most likely functions as an extracellular β-xylosidase acting on hemicellulose. Biochemical characterization of BGL11 showed an optimal pH of 5.6, and an optimal temperature of 50°C. Enzyme stability, an important parameter for industrial application, was also investigated. At 40°C purified BGL11 remained active for more than 15 hours without reduction in activity, and at 50°C, after 7 hours of incubation, BGL11 remained 60% active. The enzyme kinetic parameters of Km and Vmax using xylobiose were determined to be 3.88 mM and 38.53 μmol.min-1.mg-1, respectively, and the Kcat was 57.79 s-1. In contrast to BLG11, most β-xylosidases kinetically studied belong to the GH43 family and have been characterized only using synthetic substrates. In industry, β-xylosidases can be used for plant biomass deconstruction, and the released sugars can be fermented into valuable bio-products, ranging from the biofuel ethanol to the sugar substitute xylitol.
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Affiliation(s)
| | | | | | | | - Isabel de Souza Cunha
- Genomic Sciences and Biotechnology Program, Universidade Católica de Brasília, Brasília, DF, Brazil
| | - Julianna Peixoto
- Department of Cellular Biology, Laboratory of Enzymology, Universidade de Brasília, Brasília, DF, Brazil
| | - Ricardo Henrique Kruger
- Department of Cellular Biology, Laboratory of Enzymology, Universidade de Brasília, Brasília, DF, Brazil
| | - Eliane Ferreira Noronha
- Department of Cellular Biology, Laboratory of Enzymology, Universidade de Brasília, Brasília, DF, Brazil
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Santana-Pereira ALR, Sandoval-Powers M, Monsma S, Zhou J, Santos SR, Mead DA, Liles MR. Discovery of Novel Biosynthetic Gene Cluster Diversity From a Soil Metagenomic Library. Front Microbiol 2020; 11:585398. [PMID: 33365020 PMCID: PMC7750434 DOI: 10.3389/fmicb.2020.585398] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/16/2020] [Indexed: 12/31/2022] Open
Abstract
Soil microorganisms historically have been a rich resource for natural product discovery, yet the majority of these microbes remain uncultivated and their biosynthetic capacity is left underexplored. To identify the biosynthetic potential of soil microorganisms using a culture-independent approach, we constructed a large-insert metagenomic library in Escherichia coli from a topsoil sampled from the Cullars Rotation (Auburn, AL, United States), a long-term crop rotation experiment. Library clones were screened for biosynthetic gene clusters (BGCs) using either PCR or a NGS (next generation sequencing) multiplexed pooling strategy, coupled with bioinformatic analysis to identify contigs associated with each metagenomic clone. A total of 1,015 BGCs were detected from 19,200 clones, identifying 223 clones (1.2%) that carry a polyketide synthase (PKS) and/or a non-ribosomal peptide synthetase (NRPS) cluster, a dramatically improved hit rate compared to PCR screening that targeted type I polyketide ketosynthase (KS) domains. The NRPS and PKS clusters identified by NGS were distinct from known BGCs in the MIBiG database or those PKS clusters identified by PCR. Likewise, 16S rRNA gene sequences obtained by NGS of the library included many representatives that were not recovered by PCR, in concordance with the same bias observed in KS amplicon screening. This study provides novel resources for natural product discovery and circumvents amplification bias to allow annotation of a soil metagenomic library for a more complete picture of its functional and phylogenetic diversity.
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Affiliation(s)
| | | | - Scott Monsma
- Lucigen Corporation, Middleton, WI, United States
| | - Jinglie Zhou
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
| | - Scott R. Santos
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
| | - David A. Mead
- Varigen Biosciences Corporation, Madison, WI, United States
| | - Mark R. Liles
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
- Varigen Biosciences Corporation, Madison, WI, United States
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Prayogo FA, Budiharjo A, Kusumaningrum HP, Wijanarka W, Suprihadi A, Nurhayati N. Metagenomic applications in exploration and development of novel enzymes from nature: a review. J Genet Eng Biotechnol 2020; 18:39. [PMID: 32749574 PMCID: PMC7403272 DOI: 10.1186/s43141-020-00043-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/10/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Microbial community has an essential role in various fields, especially the industrial sector. Microbes produce metabolites in the form of enzymes, which are one of the essential compounds for industrial processes. Unfortunately, there are still numerous microbes that cannot be identified and cultivated because of the limitations of the culture-based method. The metagenomic approach is a solution for researchers to overcome these problems. Metagenomics is a strategy used to analyze the genomes of microbial communities in the environment directly. Metagenomics application used to explore novel enzymes is essential because it allows researchers to obtain data on microbial diversity, reaching of 99% and various types of genes encoding an enzyme that has not yet been identified. Basic methods in metagenomics have been developed and are commonly used in various studies. A basic understanding of metagenomics for researchers is needed, especially young researchers to support the success of the research. SHORT CONCLUSION Therefore, this review was done in order to provide a deep understanding of metagenomics. It also discussed the application and basic methods of metagenomics in the exploration of novel enzymes, especially in the latest research. Several types of enzymes, such as cellulases, proteases, and lipases, which have been explored using metagenomics, were reviewed in this article.
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Affiliation(s)
- Fitra Adi Prayogo
- Department of Biology, Faculty of Science and Mathematics, Diponegoro University, Semarang City, 50275 Indonesia
| | - Anto Budiharjo
- Biotechnology Study Program, Faculty of Science and Mathematics, Diponegoro University, Jl. Prof. Sudharto SH, Semarang, 50275 Indonesia
- Molecular and Applied Microbiology Laboratory, Center Central Laboratory of Research and Service - Diponegoro University, Jl. Prof. Sudharto SH, Semarang, 50275 Indonesia
| | | | - Wijanarka Wijanarka
- Biotechnology Study Program, Faculty of Science and Mathematics, Diponegoro University, Jl. Prof. Sudharto SH, Semarang, 50275 Indonesia
| | - Agung Suprihadi
- Biotechnology Study Program, Faculty of Science and Mathematics, Diponegoro University, Jl. Prof. Sudharto SH, Semarang, 50275 Indonesia
| | - Nurhayati Nurhayati
- Biotechnology Study Program, Faculty of Science and Mathematics, Diponegoro University, Jl. Prof. Sudharto SH, Semarang, 50275 Indonesia
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12
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Krüger A, Schäfers C, Busch P, Antranikian G. Digitalization in microbiology - Paving the path to sustainable circular bioeconomy. N Biotechnol 2020; 59:88-96. [PMID: 32750680 DOI: 10.1016/j.nbt.2020.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 06/26/2020] [Accepted: 06/27/2020] [Indexed: 11/17/2022]
Abstract
The transition to a sustainable bio-based circular economy requires cutting edge technologies that ensure economic growth with environmentally responsible action. This transition will only be feasible when the opportunities of digitalization are also exploited. Digital methods and big data handling have already found their way into life sciences and generally offer huge potential in various research areas. While computational analyses of microbial metagenome data have become state of the art, the true potential of bioinformatics remains mostly untapped so far. In this article we present challenges and opportunities of digitalization including multi-omics approaches in discovering and exploiting the microbial diversity of the planet with the aim to identify robust biocatalysts for application in sustainable bioprocesses as part of the transition from a fossil-based to a bio-based circular economy. This will contribute to solving global challenges, including utilization of natural resources, food supply, health, energy and the environment.
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Affiliation(s)
- Anna Krüger
- Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg, Germany.
| | - Christian Schäfers
- Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg, Germany.
| | - Philip Busch
- Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg, Germany.
| | - Garabed Antranikian
- Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, D-21073 Hamburg, Germany.
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Markel U, Essani KD, Besirlioglu V, Schiffels J, Streit WR, Schwaneberg U. Advances in ultrahigh-throughput screening for directed enzyme evolution. Chem Soc Rev 2020; 49:233-262. [PMID: 31815263 DOI: 10.1039/c8cs00981c] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymes are versatile catalysts and their synthetic potential has been recognized for a long time. In order to exploit their full potential, enzymes often need to be re-engineered or optimized for a given application. (Semi-) rational design has emerged as a powerful means to engineer proteins, but requires detailed knowledge about structure function relationships. In turn, directed evolution methodologies, which consist of iterative rounds of diversity generation and screening, can improve an enzyme's properties with virtually no structural knowledge. Current diversity generation methods grant us access to a vast sequence space (libraries of >1012 enzyme variants) that may hide yet unexplored catalytic activities and selectivity. However, the time investment for conventional agar plate or microtiter plate-based screening assays represents a major bottleneck in directed evolution and limits the improvements that are obtainable in reasonable time. Ultrahigh-throughput screening (uHTS) methods dramatically increase the number of screening events per time, which is crucial to speed up biocatalyst design, and to widen our knowledge about sequence function relationships. In this review, we summarize recent advances in uHTS for directed enzyme evolution. We shed light on the importance of compartmentalization to preserve the essential link between genotype and phenotype and discuss how cells and biomimetic compartments can be applied to serve this function. Finally, we discuss how uHTS can inspire novel functional metagenomics approaches to identify natural biocatalysts for novel chemical transformations.
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Affiliation(s)
- Ulrich Markel
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany.
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Patel AK, Singhania RR, Sim SJ, Pandey A. Thermostable cellulases: Current status and perspectives. BIORESOURCE TECHNOLOGY 2019; 279:385-392. [PMID: 30685132 DOI: 10.1016/j.biortech.2019.01.049] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 05/18/2023]
Abstract
It is envisaged that the utilization of lignocellulosic biomass for ethanol production for transport sector, would make cellulases the most demanded industrial enzyme. The greatest potential of cellulolytic enzymes lies in ethanol production from biomass by enzymatic hydrolysis of cellulose but low thermostability and low titer of cellulase production resulting into high cost of the enzyme which is the major set-back. A number of research groups are working on cellulase to improve its thermostability so as to be able to perform hydrolysis at elevated temperatures which would eventually increase the efficiency of cellulose hydrolysis. The technologies developed from lignocellulosic biomass via cellulose hydrolysis promise environmental and economical sustainability in the long run along with non-dependence on nonrenewable energy source. This review deals with the important sources of thermostable cellulases, mechanism, its regulation, strategies to enhance the thermostability further with respect to its importance for biofuel applications.
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Affiliation(s)
- Anil K Patel
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | | | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Ashok Pandey
- Centre for Innovation and Translational Research, Indian Institute of Toxicological Research, Lucknow 226 001, India
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Alves LDF, Westmann CA, Lovate GL, de Siqueira GMV, Borelli TC, Guazzaroni ME. Metagenomic Approaches for Understanding New Concepts in Microbial Science. Int J Genomics 2018; 2018:2312987. [PMID: 30211213 PMCID: PMC6126073 DOI: 10.1155/2018/2312987] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/21/2018] [Accepted: 07/29/2018] [Indexed: 12/15/2022] Open
Abstract
Over the past thirty years, since the dawn of metagenomic studies, a completely new (micro) universe was revealed, with the potential to have profound impacts on many aspects of the society. Remarkably, the study of human microbiome provided a new perspective on a myriad of human traits previously regarded as solely (epi-) genetically encoded, such as disease susceptibility, immunological response, and social and nutritional behaviors. In this context, metagenomics has established a powerful framework for understanding the intricate connections between human societies and microbial communities, ultimately allowing for the optimization of both human health and productivity. Thus, we have shifted from the old concept of microbes as harmful organisms to a broader panorama, in which the signal of the relationship between humans and microbes is flexible and directly dependent on our own decisions and practices. In parallel, metagenomics has also been playing a major role in the prospection of "hidden" genetic features and the development of biotechnological applications, through the discovery of novel genes, enzymes, pathways, and bioactive molecules with completely new or improved biochemical functions. Therefore, this review highlights the major milestones over the last three decades of metagenomics, providing insights into both its potentialities and current challenges.
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Affiliation(s)
- Luana de Fátima Alves
- Department of Biochemistry, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Cauã Antunes Westmann
- Department of Cell Biology, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Gabriel Lencioni Lovate
- Department of Biochemistry, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Tiago Cabral Borelli
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - María-Eugenia Guazzaroni
- Department of Biology, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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Singhania RR, Patel AK, Pandey A, Ganansounou E. Genetic modification: A tool for enhancing beta-glucosidase production for biofuel application. BIORESOURCE TECHNOLOGY 2017; 245:1352-1361. [PMID: 28596076 DOI: 10.1016/j.biortech.2017.05.126] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 05/25/2023]
Abstract
Beta-glucosidase (BGL) is a rate-limiting enzyme for cellulose hydrolysis as it acts in the final step of lignocellulosic biomass conversion to convert cellobiose into glucose, the final end product. Most of the fungal strains used for cellulase production are deficient in BGL hence BGL is supplemented into cellulases to have an efficient biomass conversion. Genetic engineering has enabled strain modification to produce BGL optimally with desired properties to be employed for biofuel applications. It has been cloned either directly into the host strains lacking BGL or into another expression system, to be overexpressed so as to be blended into BGL deficient cellulases. In this article, role of genetic engineering to overcome BGL limitations in the cellulase cocktail and its significance for biofuel applications has been critically reviewed.
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Affiliation(s)
- Reeta Rani Singhania
- DBT-IOC Advanced Bio-Energy Research Centre, Indian Oil Corporation; R&D Centre, Sector-13, Faridabad 121007, India
| | - Anil Kumar Patel
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu 96822, HI, United States.
| | - Ashok Pandey
- Center of Innovative and Applied Bioprocessing, Sector 81, Knowledge City PO Manauli, SAS Nagar, Mohali 140306, Punjab, India
| | - Edgard Ganansounou
- Bioenergy and Energy Planning Research Group, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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17
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Lewin A, Zhou J, Pham VTT, Haugen T, Zeiny ME, Aarstad O, Liebl W, Wentzel A, Liles MR. Novel archaeal thermostable cellulases from an oil reservoir metagenome. AMB Express 2017; 7:183. [PMID: 28963711 PMCID: PMC5622026 DOI: 10.1186/s13568-017-0485-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 09/20/2017] [Indexed: 01/24/2023] Open
Abstract
Microbial assemblages were sampled from an offshore deep sub-surface petroleum reservoir 2.5 km below the ocean floor off the coast of Norway, providing conditions of high temperature and pressure, to identify new thermostable enzymes. In this study, we used DNA sequences obtained directly from the sample metagenome and from a derived fosmid library to survey the functional diversity of this extreme habitat. The metagenomic fosmid library containing 11,520 clones was screened using function- and sequence-based methods to identify recombinant clones expressing carbohydrate-degrading enzymes. Open reading frames (ORFs) encoding carbohydrate-degrading enzymes were predicted by BLAST against the CAZy database, and many fosmid clones expressing carbohydrate-degrading activities were discovered by functional screening using Escherichia coli as a heterologous host. Each complete ORF predicted to encode a cellulase identified from sequence- or function-based screening was subcloned in an expression vector. Five subclones was found to have significant activity using a fluorescent cellulose model substrate, and three of these were observed to be highly thermostable. Based on phylogenetic analyses, the thermostable cellulases were derived from thermophilic Archaea and are distinct from known cellulases. Cellulase F1, obtained from function-based screening, contains two distinct cellulase modules, perhaps resulting from fusion of two archaeal cellulases and with a novel protein structure that may result in enhanced activity and thermostability. This enzyme was found to exhibit exocellulase function and to have a remarkably high activity compared to commercially available enzymes. Results from this study highlight the complementarity of hybrid approaches for enzyme discovery, combining sequence- and function-based screening.
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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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Abstract
For modern biotechnology there is a steady need to identify novel enzymes. In biotechnological applications, however, enzymes often must function under extreme and nonnatural conditions (i.e., in the presence of solvents, high temperature and/or at extreme pH values). Cellulases have many industrial applications from the generation of bioethanol, a realistic long-term energy source, to the finishing of textiles. These industrial processes require cellulolytic activity under a wide range of pH, temperature, and ionic conditions, and they are usually carried out by mixtures of cellulases. Investigation of the broad diversity of cellulolytic enzymes involved in the natural degradation of cellulose is necessary for optimizing these processes.
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Affiliation(s)
- Nele Ilmberger
- Microbiology & Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany
| | - Wolfgang R Streit
- Microbiology & Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany.
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20
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Yaung SJ, Deng L, Li N, Braff JL, Church GM, Bry L, Wang HH, Gerber GK. Improving microbial fitness in the mammalian gut by in vivo temporal functional metagenomics. Mol Syst Biol 2016; 11:788. [PMID: 26148351 PMCID: PMC4380924 DOI: 10.15252/msb.20145866] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Elucidating functions of commensal microbial genes in the mammalian gut is challenging because many commensals are recalcitrant to laboratory cultivation and genetic manipulation. We present Temporal FUnctional Metagenomics sequencing (TFUMseq), a platform to functionally mine bacterial genomes for genes that contribute to fitness of commensal bacteria in vivo. Our approach uses metagenomic DNA to construct large‐scale heterologous expression libraries that are tracked over time in vivo by deep sequencing and computational methods. To demonstrate our approach, we built a TFUMseq plasmid library using the gut commensal Bacteroides thetaiotaomicron (Bt) and introduced Escherichia coli carrying this library into germfree mice. Population dynamics of library clones revealed Bt genes conferring significant fitness advantages in E. coli over time, including carbohydrate utilization genes, with a Bt galactokinase central to early colonization, and subsequent dominance by a Bt glycoside hydrolase enabling sucrose metabolism coupled with co‐evolution of the plasmid library and E. coli genome driving increased galactose utilization. Our findings highlight the utility of functional metagenomics for engineering commensal bacteria with improved properties, including expanded colonization capabilities in vivo.
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Bandeira PT, Alnoch RC, de Oliveira AR, de Souza EM, de O. Pedrosa F, Krieger N, Piovan L. Enzymatic kinetic resolution of aliphatic sec -alcohols by LipG9, a metagenomic lipase. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcatb.2015.12.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Pandey S, Gulati S, Goyal E, Singh S, Kumar K, Nain L, Saxena A. Construction and screening of metagenomic library derived from soil for β-1, 4-endoglucanase gene. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2016. [DOI: 10.1016/j.bcab.2016.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Contemporary molecular tools in microbial ecology and their application to advancing biotechnology. Biotechnol Adv 2015; 33:1755-73. [DOI: 10.1016/j.biotechadv.2015.09.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 09/19/2015] [Accepted: 09/20/2015] [Indexed: 12/30/2022]
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24
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Metagenomics: Retrospect and Prospects in High Throughput Age. BIOTECHNOLOGY RESEARCH INTERNATIONAL 2015; 2015:121735. [PMID: 26664751 PMCID: PMC4664791 DOI: 10.1155/2015/121735] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/26/2015] [Indexed: 01/30/2023]
Abstract
In recent years, metagenomics has emerged as a powerful tool for mining of hidden microbial treasure in a culture independent manner. In the last two decades, metagenomics has been applied extensively to exploit concealed potential of microbial communities from almost all sorts of habitats. A brief historic progress made over the period is discussed in terms of origin of metagenomics to its current state and also the discovery of novel biological functions of commercial importance from metagenomes of diverse habitats. The present review also highlights the paradigm shift of metagenomics from basic study of community composition to insight into the microbial community dynamics for harnessing the full potential of uncultured microbes with more emphasis on the implication of breakthrough developments, namely, Next Generation Sequencing, advanced bioinformatics tools, and systems biology.
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25
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Mallek-Fakhfakh H, Belghith H. Physicochemical properties of thermotolerant extracellular β-glucosidase from Talaromyces thermophilus and enzymatic synthesis of cello-oligosaccharides. Carbohydr Res 2015; 419:41-50. [PMID: 26649918 DOI: 10.1016/j.carres.2015.10.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 10/23/2015] [Accepted: 10/26/2015] [Indexed: 11/29/2022]
Abstract
A thermophilic fungus, Talaromyces thermophilus that produces a novel thermotolerant extra-cellular β-glucosidase (Bgl.tls), was isolated from Tunisian soil samples. The enzyme was purified from the culture filtrates of T. thermophilus grown on lactose using gel filtration, ion exchange chromatography and FPLC. The monomeric enzyme had a molecular mass of 116.0 kDa and a high specific activity of 1429 UI/mg. Bgl.tls exhibited optimal activity at pH 5.0 and 65 °C. It was also stable over a wide range of pH (4.0-10.0) and stable at 50 °C for 34 h. Bgl.tls retained about 80% of its initial activity after 1.0 hours of preincubation at 60 °C. The Km and Vmax values recorded for pNPG were 0.25 mM and 228.7 µmol min(-1), respectively. Bgl.tls was activated by Mn(2+), Mg(2+), Ca(2+) and Co(2+) but obviously inhibited by Fe(2+) and Cu(2+). It was able to hydrolyze a variety of aryl / alkyl -β-glucosides and disaccharides as well as (1 → 6) and (1 → 4)-β-glucosidic linkages and α-glycosidic substrates, thus providing evidence for its broad substrate specificity. The enzyme also displayed high hydrolytic and transglycosylation activities. Overall, this study is the first report on the purification and physicochemical properties of a β-glucosidase secreted by T. thermophilus. The cello-oligosaccharides synthesized by this enzyme within 2 h were mainly cellotriose, cellotetraose and cellopentaose identified by HPLC and ESI-MS techniques.
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Affiliation(s)
- Hanen Mallek-Fakhfakh
- Laboratory of Biomass Valorization and Proteins Production in Eukaryotes, Center of Biotechnology of Sfax, University of Sfax, PB" 1177" 3038 Sfax, Tunisia
| | - Hafedh Belghith
- Laboratory of Biomass Valorization and Proteins Production in Eukaryotes, Center of Biotechnology of Sfax, University of Sfax, PB" 1177" 3038 Sfax, Tunisia.
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Wei Y, Zhou H, Zhang J, Zhang L, Geng A, Liu F, Zhao G, Wang S, Zhou Z, Yan X. Insight into Dominant Cellulolytic Bacteria from Two Biogas Digesters and Their Glycoside Hydrolase Genes. PLoS One 2015; 10:e0129921. [PMID: 26070087 PMCID: PMC4466528 DOI: 10.1371/journal.pone.0129921] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/13/2015] [Indexed: 12/30/2022] Open
Abstract
Diverse cellulolytic bacteria are essential for maintaining high lignocellulose degradation ability in biogas digesters. However, little was known about functional genes and gene clusters of dominant cellulolytic bacteria in biogas digesters. This is the foundation to understand lignocellulose degradation mechanisms of biogas digesters and apply these gene resource for optimizing biofuel production. A combination of metagenomic and 16S rRNA gene clone library methods was used to investigate the dominant cellulolytic bacteria and their glycoside hydrolase (GH) genes in two biogas digesters. The 16S rRNA gene analysis revealed that the dominant cellulolytic bacteria were strains closely related to Clostridium straminisolvens and an uncultured cellulolytic bacterium designated BG-1. To recover GH genes from cellulolytic bacteria in general, and BG-1 in particular, a refined assembly approach developed in this study was used to assemble GH genes from metagenomic reads; 163 GH-containing contigs ≥ 1 kb in length were obtained. Six recovered GH5 genes that were expressed in E. coli demonstrated multiple lignocellulase activities and one had high mannanase activity (1255 U/mg). Eleven fosmid clones harboring the recovered GH-containing contigs were sequenced and assembled into 10 fosmid contigs. The composition of GH genes in the 163 assembled metagenomic contigs and 10 fosmid contigs indicated that diverse GHs and lignocellulose degradation mechanisms were present in the biogas digesters. In particular, a small portion of BG-1 genome information was recovered by PhyloPythiaS analysis. The lignocellulase gene clusters in BG-1 suggested that it might use a possible novel lignocellulose degradation mechanism to efficiently degrade lignocellulose. Dominant cellulolytic bacteria of biogas digester possess diverse GH genes, not only in sequences but also in their functions, which may be applied for production of biofuel in the future.
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Affiliation(s)
- Yongjun Wei
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Haokui Zhou
- Department of Microbiology, the Chinese University of Hong Kong, the Prince of Wales Hospital, Hong Kong, China
| | - Jun Zhang
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Lei Zhang
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Alei Geng
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Fanghua Liu
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Guoping Zhao
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- Department of Microbiology, the Chinese University of Hong Kong, the Prince of Wales Hospital, Hong Kong, China
- Shanghai-MOST Key Laboratory for Health and Disease Genomics, Chinese National Human Genome Center, Shanghai, China
| | - Shengyue Wang
- Shanghai-MOST Key Laboratory for Health and Disease Genomics, Chinese National Human Genome Center, Shanghai, China
| | - Zhihua Zhou
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (XY); (ZZ)
| | - Xing Yan
- CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- * E-mail: (XY); (ZZ)
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Identification of glycosyl hydrolases from a metagenomic library of microflora in sugarcane bagasse collection site and their cooperative action on cellulose degradation. J Biosci Bioeng 2015; 119:384-91. [DOI: 10.1016/j.jbiosc.2014.09.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/12/2014] [Accepted: 09/13/2014] [Indexed: 11/19/2022]
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28
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Fouhy F, Stanton C, Cotter PD, Hill C, Walsh F. Proteomics as the final step in the functional metagenomics study of antimicrobial resistance. Front Microbiol 2015; 6:172. [PMID: 25784907 PMCID: PMC4347484 DOI: 10.3389/fmicb.2015.00172] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/15/2015] [Indexed: 01/23/2023] Open
Abstract
The majority of clinically applied antimicrobial agents are derived from natural products generated by soil microorganisms and therefore resistance is likely to be ubiquitous in such environments. This is supported by the fact that numerous clinically important resistance mechanisms are encoded within the genomes of such bacteria. Advances in genomic sequencing have enabled the in silico identification of putative resistance genes present in these microorganisms. However, it is not sufficient to rely on the identification of putative resistance genes, we must also determine if the resultant proteins confer a resistant phenotype. This will require an analysis pipeline that extends from the extraction of environmental DNA, to the identification and analysis of potential resistance genes and their resultant proteins and phenotypes. This review focuses on the application of functional metagenomics and proteomics to study antimicrobial resistance in diverse environments.
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Affiliation(s)
- Fiona Fouhy
- Teagasc - Moorepark Food Research Centre , Fermoy, Ireland
| | - Catherine Stanton
- Teagasc - Moorepark Food Research Centre , Fermoy, Ireland ; Alimentary Pharmabiotic Centre , Cork, Ireland
| | - Paul D Cotter
- Teagasc - Moorepark Food Research Centre , Fermoy, Ireland ; Alimentary Pharmabiotic Centre , Cork, Ireland
| | - Colin Hill
- Alimentary Pharmabiotic Centre , Cork, Ireland ; School of Microbiology, University College Cork , Cork, Ireland
| | - Fiona Walsh
- Department of Biology, National University of Ireland Maynooth , Maynooth, Ireland
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Abstract
The recent developments of metagenomics permit an extremely high-resolution molecular scan of the intestinal microbiota giving new insights and opening perspectives for clinical applications. Beyond the unprecedented vision of the intestinal microbiota given by large-scale quantitative metagenomics studies, such as the EU MetaHIT project, functional metagenomics tools allow the exploration of fine interactions between food constituents, microbiota and host, leading to the identification of signals and intimate mechanisms of crosstalk, especially between bacteria and human cells. Cloning of large genome fragments, either from complex intestinal communities or from selected bacteria, allows the screening of these biological resources for bioactivity towards complex plant polymers or functional food such as prebiotics. This permitted identification of novel carbohydrate-active enzyme families involved in dietary fibre and host glycan breakdown, and highlighted unsuspected bacterial players at the top of the intestinal microbial food chain. Similarly, exposure of fractions from genomic and metagenomic clones onto human cells engineered with reporter systems to track modulation of immune response, cell proliferation or cell metabolism has allowed the identification of bioactive clones modulating key cell signalling pathways or the induction of specific genes. This opens the possibility to decipher mechanisms by which commensal bacteria or candidate probiotics can modulate the activity of cells in the intestinal epithelium or even in distal organs such as the liver, adipose tissue or the brain. Hence, in spite of our inability to culture many of the dominant microbes of the human intestine, functional metagenomics open a new window for the exploration of food–microbe–host crosstalk.
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30
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Sharma S, Vakhlu J. Metagenomics as advanced screening methods for novel microbial metabolites. Microb Biotechnol 2014. [DOI: 10.1201/b17587-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Liebl W, Angelov A, Juergensen J, Chow J, Loeschcke A, Drepper T, Classen T, Pietruszka J, Ehrenreich A, Streit WR, Jaeger KE. Alternative hosts for functional (meta)genome analysis. Appl Microbiol Biotechnol 2014; 98:8099-109. [PMID: 25091044 DOI: 10.1007/s00253-014-5961-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 11/25/2022]
Abstract
Microorganisms are ubiquitous on earth, often forming complex microbial communities in numerous different habitats. Most of these organisms cannot be readily cultivated in the laboratory using standard media and growth conditions. However, it is possible to gain access to the vast genetic, enzymatic, and metabolic diversity present in these microbial communities using cultivation-independent approaches such as sequence- or function-based metagenomics. Function-based analysis is dependent on heterologous expression of metagenomic libraries in a genetically amenable cloning and expression host. To date, Escherichia coli is used in most cases; however, this has the drawback that many genes from heterologous genomes and complex metagenomes are expressed in E. coli either at very low levels or not at all. This review emphasizes the importance of establishing alternative microbial expression systems consisting of different genera and species as well as customized strains and vectors optimized for heterologous expression of membrane proteins, multigene clusters encoding protein complexes or entire metabolic pathways. The use of alternative host-vector systems will complement current metagenomic screening efforts and expand the yield of novel biocatalysts, metabolic pathways, and useful metabolites to be identified from environmental samples.
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Affiliation(s)
- Wolfgang Liebl
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Str. 4, 85654, Freising, Germany,
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Sae-Lee R, Boonmee A. Newly derived GH43 gene from compost metagenome showing dual xylanase and cellulase activities. Folia Microbiol (Praha) 2014; 59:409-17. [PMID: 24737296 DOI: 10.1007/s12223-014-0313-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 03/05/2014] [Indexed: 10/25/2022]
Abstract
A metagenomic fosmid library was constructed from compost microbial communities that were collected from various farms throughout the Khon Kaen province, Thailand. The library was enriched in carboxymethylcellulose (CM-cellulose)--containing media prior to the screening of clones capable of degrading cellulosic materials. Two clones were selected for further subcloning and sequencing based on different patterns from restriction analysis. Deduced amino acid analysis of possible ORFs revealed one novel gene encoding an enzyme belonging to glycosyl hydrolase family 43 (GH43), which is a GH family rarely found in metagenomic studies. The most notable finding is that this enzyme, designated as Biof1_09, shows dual activities, namely endocellulase and endoxylanase activities. Biof1_09 showed greater than 50% of its activity under acidic conditions ranging from pH 3.5 to 5.5 with a pH optimum of 4.5. The optimum temperature of this enzyme was between 45 and 55 °C with an optimum of 50 °C. The properties of Biof1_09 make this enzyme an attractive candidate for large-scale expression for use in lignocellulose degradation for various bioprocess applications, including bioethanol fermentation.
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Affiliation(s)
- Ritthironk Sae-Lee
- Department of Microbiology, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand
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Molecular Characterization of the Archaeal Diversity in Vlasa Hot Spring, Bulgaria, by using 16S rRNA and Glycoside Hydrolase Family 4 Genes. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.2478/v10133-010-0065-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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34
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Bergmann JC, Costa OYA, Gladden JM, Singer S, Heins R, D'haeseleer P, Simmons BA, Quirino BF. Discovery of two novel β-glucosidases from an Amazon soil metagenomic library. FEMS Microbiol Lett 2013; 351:147-55. [PMID: 24236615 DOI: 10.1111/1574-6968.12332] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/07/2013] [Accepted: 11/07/2013] [Indexed: 11/30/2022] Open
Abstract
An Amazon soil microbial community metagenomic fosmid library was functionally screened for β-glucosidase activity. Contig analysis of positive clones revealed the presence of two ORFs encoding novel β-glucosidases, AmBGL17 and AmBGL18, from the GH3 and GH1 families, respectively. Both AmBGL17 and AmBGL18 were functionally identified as β-glucosidases. The enzymatic activity of AmBGL17 was further characterized. AmBGL17 was tested with different substrates and showed highest activity on pNPβG substrate with an optimum temperature of 45 °C and an optimum pH of 6. AmBGL17 showed a Vmax of 116 mM s(-1) and Km of 0.30 ± 0.017 mM. This is the first report of β-glucosidases from an Amazon soil microbial community using a metagenomic approach.
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Affiliation(s)
- Jessica C Bergmann
- Genomic Sciences and Biotechnology Program, Universidade Católica de Brasília, Brasília, Brazil
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35
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Lee MH, Lee SW. Bioprospecting potential of the soil metagenome: novel enzymes and bioactivities. Genomics Inform 2013; 11:114-20. [PMID: 24124406 PMCID: PMC3794083 DOI: 10.5808/gi.2013.11.3.114] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/14/2013] [Accepted: 08/20/2013] [Indexed: 11/22/2022] Open
Abstract
The microbial diversity in soil ecosystems is higher than in any other microbial ecosystem. The majority of soil microorganisms has not been characterized, because the dominant members have not been readily culturable on standard cultivation media; therefore, the soil ecosystem is a great reservoir for the discovery of novel microbial enzymes and bioactivities. The soil metagenome, the collective microbial genome, could be cloned and sequenced directly from soils to search for novel microbial resources. This review summarizes the microbial diversity in soils and the efforts to search for microbial resources from the soil metagenome, with more emphasis on the potential of bioprospecting metagenomics and recent discoveries.
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Affiliation(s)
- Myung Hwan Lee
- Department of Applied Biology, Dong-A University, Busan 604-714, Korea
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36
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Lu J, Du L, Wei Y, Hu Y, Huang R. Expression and characterization of a novel highly glucose-tolerant β-glucosidase from a soil metagenome. Acta Biochim Biophys Sin (Shanghai) 2013; 45:664-73. [PMID: 23752618 DOI: 10.1093/abbs/gmt061] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A β-glucosidase gene unbgl1A was isolated by the function-based screening of a metagenomic library and the enzyme protein was expressed in Escherichia coli, purified, and biochemically characterized. The enzyme Unbgl1A had a Km value of 2.09 ± 0.31 mM, and a Vmax value of 183.90 ± 9.61 μmol min(-1) mg(-1) under the optimal reaction conditions, which were pH 6.0 at 50°C. Unbgl1A can be activated by a variety of monosaccharides, disaccharides, and NaCl, and exhibits a high level of stability at high concentration of NaCl. Two prominent features for this enzyme are: (i) high glucose tolerance. It can be tolerant to glucose as high as 2000 mM, with Ki = 1500 mM; (ii) high NaCl tolerance. Its activity is not affected by 600 mM NaCl. The enzyme showed transglucosylation activities resulting in the formation of cellotriose from cellobiose. These properties of Unbgl1A should have important practical implication in its potential applications for better industrial production of glucose or bioethanol started from lignocellulosic biomass.
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Affiliation(s)
- Jian Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530005, China
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37
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Mining of novel thermo-stable cellulolytic genes from a thermophilic cellulose-degrading consortium by metagenomics. PLoS One 2013; 8:e53779. [PMID: 23341999 PMCID: PMC3544849 DOI: 10.1371/journal.pone.0053779] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 12/03/2012] [Indexed: 02/06/2023] Open
Abstract
In this study, metagenomics was applied to characterize the microbial community and to discover carbohydrate-active genes of an enriched thermophilic cellulose-degrading sludge. The 16S analysis showed that the sludge microbiome was dominated by genus of cellulolytic Clostridium and methanogenesis Methanothermobacter. In order to retrieve genes from the metagenome, de novo assembly of the 11,930,760 Illumina 100 bp paired-end reads (totally 1.2 Gb) was carried out. 75% of all reads was utilized in the de novo assembly. 31,499 ORFs (Open Reading Frame) with an average length of 852 bp were predicted from the assembly; and 64% of these ORFs were predicted to present full-length genes. Based on the Hidden Markol Model, 253 of the predicted thermo-stable genes were identified as putatively carbohydrate-active. Among them the relative dominance of GH9 (Glycoside Hydrolase) and corresponding CBM3 (Carbohydrate Binding Module) revealed a cellulosome-based attached metabolism of polysaccharide in the thermophilic sludge. The putative carbohydrate-active genes ranged from 20% to 100% amino acid sequence identity to known proteins in NCBI nr database, with half of them showed less than 50% similarity. In addition, the coverage of the genes (in terms of ORFs) identified in the sludge were developed into three clear trends (112×, 29× and 8×) in which 85% of the high coverage trend (112×) mainly consisted of phylum of Firmicutes while 49.3% of the 29× trend was affiliated to the phylum of Chloroflexi.
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38
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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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39
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McMahon MD, Guan C, Handelsman J, Thomas MG. Metagenomic analysis of Streptomyces lividans reveals host-dependent functional expression. Appl Environ Microbiol 2012; 78:3622-9. [PMID: 22427497 PMCID: PMC3346366 DOI: 10.1128/aem.00044-12] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 03/07/2012] [Indexed: 11/20/2022] Open
Abstract
Most functional metagenomic studies have been limited by the poor expression of many genes derived from metagenomic DNA in Escherichia coli, which has been the predominant surrogate host to date. To expand the range of expressed genes, we developed tools for construction and functional screening of metagenomic libraries in Streptomyces lividans. We expanded on previously published protocols by constructing a system that enables retrieval and characterization of the metagenomic DNA from biologically active clones. To test the functionality of these methods, we constructed and screened two metagenomic libraries in S. lividans. One was constructed with pooled DNA from 14 bacterial isolates cultured from Alaskan soil and the second with DNA directly extracted from the same soil. Functional screening of these libraries identified numerous clones with hemolytic activity, one clone that produces melanin by a previously unknown mechanism, and one that induces the overproduction of a secondary metabolite native to S. lividans. All bioactive clones were functional in S. lividans but not in E. coli, demonstrating the advantages of screening metagenomic libraries in more than one host.
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Affiliation(s)
- Matthew D. McMahon
- Department of Bacteriology
- Microbiology Doctoral Training Program, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Changhui Guan
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Jo Handelsman
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | - Michael G. Thomas
- Department of Bacteriology
- Microbiology Doctoral Training Program, University of Wisconsin—Madison, Madison, Wisconsin, USA
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40
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Schmieder R, Edwards R. Insights into antibiotic resistance through metagenomic approaches. Future Microbiol 2012; 7:73-89. [PMID: 22191448 DOI: 10.2217/fmb.11.135] [Citation(s) in RCA: 181] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The consequences of bacterial infections have been curtailed by the introduction of a wide range of antibiotics. However, infections continue to be a leading cause of mortality, in part due to the evolution and acquisition of antibiotic-resistance genes. Antibiotic misuse and overprescription have created a driving force influencing the selection of resistance. Despite the problem of antibiotic resistance in infectious bacteria, little is known about the diversity, distribution and origins of resistance genes, especially for the unculturable majority of environmental bacteria. Functional and sequence-based metagenomics have been used for the discovery of novel resistance determinants and the improved understanding of antibiotic-resistance mechanisms in clinical and natural environments. This review discusses recent findings and future challenges in the study of antibiotic resistance through metagenomic approaches.
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Affiliation(s)
- Robert Schmieder
- Computational Science Research Center & Department of Computer Science, San Diego State University, San Diego, CA 92182, USA
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41
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Expression and characterization of a novel metagenome-derived cellulase Exo2b and its application to improve cellulase activity in Trichoderma reesei. Appl Microbiol Biotechnol 2012; 96:951-62. [DOI: 10.1007/s00253-012-3873-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 12/25/2011] [Accepted: 12/27/2011] [Indexed: 11/26/2022]
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42
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Jüergensen J, Ilmberger N, Streit WR. Screening for cellulases with industrial value and their use in biomass conversion. Methods Mol Biol 2012; 834:1-16. [PMID: 22144349 DOI: 10.1007/978-1-61779-483-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Cellulose is an easily renewable and highly occurring resource. To take advantage of this great potential, there is a constant need of new cellulose degrading enzymes. In industrial applications enzymes have to function under extreme conditions like high temperature, very acidic or basic pH and different solvents. Cellulases have a huge area of application, for example the textile and food industry as well as the generation of bioethanol as an alternative energy source. They have the ability to yield a great energetic potential, but there is still a lack of economical technologies to conquer the stability of the cellulose structure. Via metagenomic research and well-directed screening, it is possible to detect new cellulases, which are active under tough industrial conditions.
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Affiliation(s)
- Julia Jüergensen
- Abteilung für Mikrobiologie und Biotechnologie, Universität Hamburg, Hamburg, Germany
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43
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Identification and Characterization of a Cellulase-Encoding Gene from the Buffalo Rumen Metagenomic Library. Biosci Biotechnol Biochem 2012; 76:1075-84. [DOI: 10.1271/bbb.110786] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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44
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Džunková M, D’Auria G, Pérez-Villarroya D, Moya A. Hybrid sequencing approach applied to human fecal metagenomic clone libraries revealed clones with potential biotechnological applications. PLoS One 2012; 7:e47654. [PMID: 23082187 PMCID: PMC3474745 DOI: 10.1371/journal.pone.0047654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 09/14/2012] [Indexed: 02/07/2023] Open
Abstract
Natural environments represent an incredible source of microbial genetic diversity. Discovery of novel biomolecules involves biotechnological methods that often require the design and implementation of biochemical assays to screen clone libraries. However, when an assay is applied to thousands of clones, one may eventually end up with very few positive clones which, in most of the cases, have to be "domesticated" for downstream characterization and application, and this makes screening both laborious and expensive. The negative clones, which are not considered by the selected assay, may also have biotechnological potential; however, unfortunately they would remain unexplored. Knowledge of the clone sequences provides important clues about potential biotechnological application of the clones in the library; however, the sequencing of clones one-by-one would be very time-consuming and expensive. In this study, we characterized the first metagenomic clone library from the feces of a healthy human volunteer, using a method based on 454 pyrosequencing coupled with a clone-by-clone Sanger end-sequencing. Instead of whole individual clone sequencing, we sequenced 358 clones in a pool. The medium-large insert (7-15 kb) cloning strategy allowed us to assemble these clones correctly, and to assign the clone ends to maintain the link between the position of a living clone in the library and the annotated contig from the 454 assembly. Finally, we found several open reading frames (ORFs) with previously described potential medical application. The proposed approach allows planning ad-hoc biochemical assays for the clones of interest, and the appropriate sub-cloning strategy for gene expression in suitable vectors/hosts.
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Affiliation(s)
- Mária Džunková
- Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
- CIBER en Epidemiología y Salud Pública (CIBEResp), Madrid, Spain
| | - Giuseppe D’Auria
- Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
- CIBER en Epidemiología y Salud Pública (CIBEResp), Madrid, Spain
- * E-mail:
| | - David Pérez-Villarroya
- Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | - Andrés Moya
- Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
- CIBER en Epidemiología y Salud Pública (CIBEResp), Madrid, Spain
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Li H, Huang Y, Zhang J, Du J, Tan H, Lu Y, Zhou S. Identification and characterization of a novel methionine γ-lyase gene from deep-sea sediment metagenomic library. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0748-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Fujii K, Kuwahara A, Nakamura K, Yamashita Y. Development of a simple cultivation method for isolating hitherto-uncultured cellulase-producing microbes. Appl Microbiol Biotechnol 2011; 91:1183-92. [DOI: 10.1007/s00253-011-3376-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 05/02/2011] [Accepted: 05/03/2011] [Indexed: 11/30/2022]
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47
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Jiang C, Li SX, Luo FF, Jin K, Wang Q, Hao ZY, Wu LL, Zhao GC, Ma GF, Shen PH, Tang XL, Wu B. Biochemical characterization of two novel β-glucosidase genes by metagenome expression cloning. BIORESOURCE TECHNOLOGY 2011; 102:3272-3278. [PMID: 20971635 DOI: 10.1016/j.biortech.2010.09.114] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/28/2010] [Accepted: 09/28/2010] [Indexed: 05/30/2023]
Abstract
Two novel β-glucosidase genes designated as bgl1D and bgl1E, which encode 172- and 151-aa peptides, respectively, were cloned by function-based screening of a metagenomic library from uncultured soil microorganisms. Sequence analyses indicated that Bgl1D and Bgl1E exhibited lower similarities with some putative β-glucosidases. Functional characterization through high-performance liquid chromatography demonstrated that purified recombinant Bgl1D and Bgl1E proteins hydrolyzed D-glucosyl-β-(1-4)-D-glucose to glucose. Using p-nitrophenyl-β-D-glucoside as substrate, K(m) was 0.54 and 2.11 mM, and k(cat)/K(m) was 1489 and 787 mM(-1) min(-1) for Bgl1D and Bgl1E, respectively. The optimum pH and temperature for Bgl1D was pH 10.0 and 30°C, while the optimum values for Bgl1E were pH 10.0 and 25°C. Bgl1D exhibited habitat-specific characteristics, including higher activity in lower temperature and at high concentrations of AlCl(3) and LiCl. Bgl1D also displayed remarkable activity across a broad pH range (5.5-10.5), making it a potential candidate for industrial applications.
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Affiliation(s)
- Chengjian Jiang
- Guangxi Key Laboratory of Subtropical Bioresources Conservation and Utilization, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, People's Republic of China
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48
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Abstract
Metagenomics has revolutionized microbiology by paving the way for a cultivation-independent assessment and exploitation of microbial communities present in complex ecosystems. Metagenomics comprising construction and screening of metagenomic DNA libraries has proven to be a powerful tool to isolate new enzymes and drugs of industrial importance. So far, the majority of the metagenomically exploited habitats comprised temperate environments, such as soil and marine environments. Recently, metagenomes of extreme environments have also been used as sources of novel biocatalysts. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body, and ocean water. Analyses of these data sets opened a window into the enormous taxonomic and functional diversity of environmental microbial communities. To assess the functional dynamics of microbial communities, metatranscriptomics and metaproteomics have been developed. The combination of DNA-based, mRNA-based, and protein-based analyses of microbial communities present in different environments is a way to elucidate the compositions, functions, and interactions of microbial communities and to link these to environmental processes.
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49
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Abstract
Metagenomics has revolutionized microbiology by paving the way for a cultivation-independent assessment and exploitation of microbial communities present in complex ecosystems. Metagenomics comprising construction and screening of metagenomic DNA libraries has proven to be a powerful tool to isolate new enzymes and drugs of industrial importance. So far, the majority of the metagenomically exploited habitats comprised temperate environments, such as soil and marine environments. Recently, metagenomes of extreme environments have also been used as sources of novel biocatalysts. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body, and ocean water. Analyses of these data sets opened a window into the enormous taxonomic and functional diversity of environmental microbial communities. To assess the functional dynamics of microbial communities, metatranscriptomics and metaproteomics have been developed. The combination of DNA-based, mRNA-based, and protein-based analyses of microbial communities present in different environments is a way to elucidate the compositions, functions, and interactions of microbial communities and to link these to environmental processes.
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50
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Liu J, Liu WD, Zhao XL, Shen WJ, Cao H, Cui ZL. Cloning and functional characterization of a novel endo-β-1,4-glucanase gene from a soil-derived metagenomic library. Appl Microbiol Biotechnol 2010; 89:1083-92. [DOI: 10.1007/s00253-010-2828-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 08/06/2010] [Accepted: 08/06/2010] [Indexed: 11/25/2022]
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