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Iasakov T. Evolution End Classification of tfd Gene Clusters Mediating Bacterial Degradation of 2,4-Dichlorophenoxyacetic Acid (2,4-D). Int J Mol Sci 2023; 24:14370. [PMID: 37762674 PMCID: PMC10531765 DOI: 10.3390/ijms241814370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/11/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023] Open
Abstract
The tfd (tfdI and tfdII) are gene clusters originally discovered in plasmid pJP4 which are involved in the bacterial degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) via the ortho-cleavage pathway of chlorinated catechols. They share this activity, with respect to substituted catechols, with clusters tcb and clc. Although great effort has been devoted over nearly forty years to exploring the structural diversity of these clusters, their evolution has been poorly resolved to date, and their classification is clearly obsolete. Employing comparative genomic and phylogenetic approaches has revealed that all tfd clusters can be classified as one of four different types. The following four-type classification and new nomenclature are proposed: tfdI, tfdII, tfdIII and tfdIV(A,B,C). Horizontal gene transfer between Burkholderiales and Sphingomonadales provides phenomenal linkage between tfdI, tfdII, tfdIII and tfdIV type clusters and their mosaic nature. It is hypothesized that the evolution of tfd gene clusters proceeded within first (tcb, clc and tfdI), second (tfdII and tfdIII) and third (tfdIV(A,B,C)) evolutionary lineages, in each of which, the genes were clustered in specific combinations. Their clustering is discussed through the prism of hot spots and driving forces of various models, theories, and hypotheses of cluster and operon formation. Two hypotheses about series of gene deletions and displacements are also proposed to explain the structural variations across members of clusters tfdII and tfdIII, respectively. Taking everything into account, these findings reconstruct the phylogeny of tfd clusters, have delineated their evolutionary trajectories, and allow the contribution of various evolutionary processes to be assessed.
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Affiliation(s)
- Timur Iasakov
- Ufa Institute of Biology, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya, 69, 450054 Ufa, Russia
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Bhatt P, Bhandari G, Bhatt K, Maithani D, Mishra S, Gangola S, Bhatt R, Huang Y, Chen S. Plasmid-mediated catabolism for the removal of xenobiotics from the environment. JOURNAL OF HAZARDOUS MATERIALS 2021; 420:126618. [PMID: 34329102 DOI: 10.1016/j.jhazmat.2021.126618] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/27/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
The large-scale application of xenobiotics adversely affects the environment. The genes that are present in the chromosome of the bacteria are considered nonmobile, whereas the genes present on the plasmids are considered mobile genetic elements. Plasmids are considered indispensable for xenobiotic degradation into the contaminated environment. In the contaminated sites, bacteria with plasmids can transfer the mobile genetic element into another strain. This mechanism helps in spreading the catabolic genes into the bacterial population at the contaminated sites. The indigenous microbial strains with such degradative plasmids are important for the bioremediation of xenobiotics. Environmental factors play a critical role in the conjugation efficiency, which is involved in the bioremediation of the xenobiotics at the contaminated sites. However, there is still a need for more research to fill in the gaps regarding plasmids and their impact on bioremediation. This review explores the role of bacterial plasmids in the bioremediation of xenobiotics from contaminated environments.
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Affiliation(s)
- Pankaj Bhatt
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Geeta Bhandari
- Department of Biochemistry and Biotechnology, Sardar Bhagwan Singh University, Dehradun 248161, Uttarakhand, India
| | - Kalpana Bhatt
- Department of Botany and Microbiology, Gurukul Kangri University, Haridwar 249404, Uttarakhand, India
| | - Damini Maithani
- Department of Microbiology, G.B Pant University of Agriculture and Technology Pantnagar, U.S Nagar, Uttarakhand, India
| | - Sandhya Mishra
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Saurabh Gangola
- School of Agriculture, Graphic Era Hill University, Bhimtal Campus, 263136, Uttarakhand, India
| | - Rakesh Bhatt
- Department of Civil Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh, India
| | - Yaohua Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.
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Öztürk B, Werner J, Meier-Kolthoff JP, Bunk B, Spröer C, Springael D. Comparative Genomics Suggests Mechanisms of Genetic Adaptation toward the Catabolism of the Phenylurea Herbicide Linuron in Variovorax. Genome Biol Evol 2021; 12:827-841. [PMID: 32359160 PMCID: PMC7313664 DOI: 10.1093/gbe/evaa085] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2020] [Indexed: 01/07/2023] Open
Abstract
Biodegradation of the phenylurea herbicide linuron appears a specialization within a specific clade of the Variovorax genus. The linuron catabolic ability is likely acquired by horizontal gene transfer but the mechanisms involved are not known. The full-genome sequences of six linuron-degrading Variovorax strains isolated from geographically distant locations were analyzed to acquire insight into the mechanisms of genetic adaptation toward linuron metabolism. Whole-genome sequence analysis confirmed the phylogenetic position of the linuron degraders in a separate clade within Variovorax and indicated that they unlikely originate from a common ancestral linuron degrader. The linuron degraders differentiated from Variovorax strains that do not degrade linuron by the presence of multiple plasmids of 20–839 kb, including plasmids of unknown plasmid groups. The linuron catabolic gene clusters showed 1) high conservation and synteny and 2) strain-dependent distribution among the different plasmids. Most of them were bordered by IS1071 elements forming composite transposon structures, often in a multimeric array configuration, appointing IS1071 as a key element in the recruitment of linuron catabolic genes in Variovorax. Most of the strains carried at least one (catabolic) broad host range plasmid that might have been a second instrument for catabolic gene acquisition. We conclude that clade 1 Variovorax strains, despite their different geographical origin, made use of a limited genetic repertoire regarding both catabolic functions and vehicles to acquire linuron biodegradation.
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Affiliation(s)
- Başak Öztürk
- Junior Research Group Microbial Biotechnology, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,Division of Soil and Water Management, KU Leuven, Belgium
| | - Johannes Werner
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research, Rostock, Germany
| | - Jan P Meier-Kolthoff
- Department Bioinformatics and Databases, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Boyke Bunk
- Department Bioinformatics and Databases, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Department Bioinformatics and Databases, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dirk Springael
- Division of Soil and Water Management, KU Leuven, Belgium
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Gao YZ, Palatucci ML, Waidner LA, Li T, Guo Y, Spain JC, Zhou NY. A Nag-like dioxygenase initiates 3,4-dichloronitrobenzene degradation via 4,5-dichlorocatechol in Diaphorobacter sp. strain JS3050. Environ Microbiol 2020; 23:1053-1065. [PMID: 33103811 DOI: 10.1111/1462-2920.15295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 11/30/2022]
Abstract
The chemical synthesis intermediate 3,4-dichloronitrobenzene (3,4-DCNB) is an environmental pollutant. Diaphorobacter sp. strain JS3050 utilizes 3,4-DCNB as a sole source of carbon, nitrogen and energy. However, the molecular determinants of its catabolism are poorly understood. Here, the complete genome of strain JS3050 was sequenced and key genes were expressed heterologously to establish the details of its degradation pathway. A chromosome-encoded three-component nitroarene dioxygenase (DcnAaAbAcAd) converted 3,4-DCNB stoichiometrically to 4,5-dichlorocatechol, which was transformed to 3,4-dichloromuconate by a plasmid-borne ring-cleavage chlorocatechol 1,2-dioxygenase (DcnC). On the chromosome, there are also genes encoding enzymes (DcnDEF) responsible for the subsequent transformation of 3,4-dichloromuconate to β-ketoadipic acid. The fact that the genes responsible for the catabolic pathway are separately located on plasmid and chromosome indicates that recent assembly and ongoing evolution of the genes encoding the pathway is likely. The regiospecificity of 4,5-dichlorocatechol formation from 3,4-DCNB by DcnAaAbAcAd represents a sophisticated evolution of the nitroarene dioxygenase that avoids misrouting of toxic intermediates. The findings enhance the understanding of microbial catabolic diversity during adaptive evolution in response to xenobiotics released into the environment.
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Affiliation(s)
- Yi-Zhou Gao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Mallory L Palatucci
- Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Pensacola, FL, 32514-5751, USA
| | - Lisa A Waidner
- Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Pensacola, FL, 32514-5751, USA
| | - Tao Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yuan Guo
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jim C Spain
- Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Pensacola, FL, 32514-5751, USA
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
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Ramakrishnan B, Venkateswarlu K, Sethunathan N, Megharaj M. Local applications but global implications: Can pesticides drive microorganisms to develop antimicrobial resistance? THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:177-189. [PMID: 30445319 DOI: 10.1016/j.scitotenv.2018.11.041] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/02/2018] [Accepted: 11/03/2018] [Indexed: 05/07/2023]
Abstract
Pesticides are an important agricultural input, and the introduction of new active ingredients with increased efficiencies drives their higher production and consumption worldwide. Inappropriate application and storage of these chemicals often contaminate plant tissues, air, water, or soil environments. The presence of pesticides can lead to developing tolerance, resistance or persistence and even the capabilities to degrade them by the microbiomes of theses environments. The pesticide-degrading microorganisms gain and employ several mechanisms for attraction (chemotaxis), membrane transport systems, efflux pumps, enzymes and genetical make-up with plasmid and chromosome encoded catabolic genes for degradation. Even the evolution and the mechanisms of inheritance for pesticide-degradation as a functional trait in several microorganisms are beginning to be understood. Because of the commonalities in the microbial responses of sensing and uptake, and adaptation due to the selection pressures of pesticides and antimicrobial substances including antibiotics, the pesticide-degraders have higher chances of possessing antimicrobial resistance as a surplus functional trait. This review critically examines the probabilities of pesticide contamination of soil and foliage, the knowledge gaps in the regulation and storage of pesticide chemicals, and the human implications of pesticide-degrading microorganisms with antimicrobial resistance in the global strategy of 'One Health'.
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Affiliation(s)
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapur 515055, India
| | - Nambrattil Sethunathan
- Flat No. 103, Ushodaya Apartments, Sri Venkateswara Officers Colony, Ramakrishnapuram, Secunderabad 500056, India
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER) and Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, ATC Building, Callaghan, NSW 2308, Australia.
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Jang J, Sakai Y, Senoo K, Ishii S. Potentially Mobile Denitrification Genes Identified in Azospirillum sp. Strain TSH58. Appl Environ Microbiol 2019; 85:e02474-18. [PMID: 30413471 PMCID: PMC6328785 DOI: 10.1128/aem.02474-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/05/2018] [Indexed: 11/20/2022] Open
Abstract
Denitrification ability is sporadically distributed among diverse bacteria, archaea, and fungi. In addition, disagreement has been found between denitrification gene phylogenies and the 16S rRNA gene phylogeny. These facts have suggested potential occurrences of horizontal gene transfer (HGT) for the denitrification genes. However, evidence of HGT has not been clearly presented thus far. In this study, we identified the sequences and the localization of the nitrite reductase genes in the genomes of 41 denitrifying Azospirillum sp. strains and searched for mobile genetic elements that contain denitrification genes. All Azospirillum sp. strains examined in this study possessed multiple replicons (4 to 11 replicons), with their sizes ranging from 7 to 1,031 kbp. Among those, the nitrite reductase gene nirK was located on large replicons (549 to 941 kbp). Genome sequencing showed that Azospirillum strains that had similar nirK sequences also shared similar nir-nor gene arrangements, especially between the TSH58, Sp7T, and Sp245 strains. In addition to the high similarity between nir-nor gene clusters among the three Azospirillum strains, a composite transposon structure was identified in the genome of strain TSH58, which contains the nir-nor gene cluster and the novel IS6 family insertion sequences (ISAz581 and ISAz582). The nirK gene within the composite transposon system was actively transcribed under denitrification-inducing conditions. Although not experimentally verified in this study, the composite transposon system containing the nir-nor gene cluster could be transferred to other cells if it is moved to a prophage region and the phage becomes activated and released outside the cells. Taken together, strain TSH58 most likely acquired its denitrification ability by HGT from closely related Azospirillum sp. denitrifiers.IMPORTANCE The evolutionary history of denitrification is complex. While the occurrence of horizontal gene transfer has been suggested for denitrification genes, most studies report circumstantial evidences, such as disagreement between denitrification gene phylogenies and the 16S rRNA gene phylogeny. Based on the comparative genome analyses of Azospirillum sp. denitrifiers, we identified denitrification genes, including nirK and norCBQD, located on a mobile genetic element in the genome of Azospirillum sp. strain TSH58. The nirK was actively transcribed under denitrification-inducing conditions. Since this gene was the sole nitrite reductase gene in strain TSH58, this strain most likely benefitted by acquiring denitrification genes via horizontal gene transfer. This finding will significantly advance our scientific knowledge regarding the ecology and evolution of denitrification.
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Affiliation(s)
- Jeonghwan Jang
- BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA
| | - Yoriko Sakai
- Institute for Agro-Environmental Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
| | - Keishi Senoo
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Satoshi Ishii
- BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, Minnesota, USA
- Microbial and Plant Genomics Institute, University of Minnesota, St. Paul, Minnesota, USA
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Nguyen TPO, Hansen MA, Hansen LH, Horemans B, Sørensen SJ, De Mot R, Springael D. Intra- and inter-field diversity of 2,4-dichlorophenoxyacetic acid-degradative plasmids and their tfd catabolic genes in rice fields of the Mekong delta in Vietnam. FEMS Microbiol Ecol 2019; 95:5149497. [PMID: 30380047 DOI: 10.1093/femsec/fiy214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 10/29/2018] [Indexed: 11/14/2022] Open
Abstract
The tfd genes mediating degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) differ in composition and organization in bacterial isolates from different geographical origin and are carried by different types of mobile genetic elements (MGE). It is not known whether such global diversity of 2,4-D-catabolic MGE and their tfd gene cargo is reflected in the diversity at field scale. The genomic context of the 2,4-D catabolic genes of 2,4-D-degrading isolates from two rice fields with a 2,4-D application history, located in two distant provinces of the Vietnam Mekong delta, was compared. All isolates were β-proteobacteria, were unique for each rice field and carried the catabolic genes on MGE and especially plasmids. Most plasmids were IncP-1β plasmids and carried tfd clusters highly similar to those of the IncP-1β plasmid pJP4, typified by two chlorophenol catabolic gene modules (tfd-I and tfd-II). IncP-1β plasmids from the same field showed small deletions and/or insertions in accessory metabolic genes. One plasmid belonged to an unclassified plasmid group and carries a copy of both tfdA and tfd-II identical to those in the IncP-1β plasmids. Our results indicate intra-field evolution and inter-field exchange of 2,4-D-catabolic IncP-1β plasmids as well as the exchange of tfd genes between different plasmids within a confined local environment.
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Affiliation(s)
- Thi Phi Oanh Nguyen
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, Heverlee-Leuven B-3001, Belgium.,Department of Biology, College of Natural Sciences, Can Tho University, Campus II, 3/2 street, Ninh Kieu district, Can Tho City, Vietnam
| | - Martin Asser Hansen
- Section for Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen DK-2100, Denmark
| | - Lars Hestbjerg Hansen
- Section for Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen DK-2100, Denmark.,Department of Environmental Science - Environmental Microbiology & Biotechnology, Aarhus University, Frederiksborgvej 399, Building 7411 B2.12, Roskilde DK-4000, Denmark
| | - Benjamin Horemans
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, Heverlee-Leuven B-3001, Belgium
| | - Søren Johannes Sørensen
- Section for Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen DK-2100, Denmark
| | - René De Mot
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, Heverlee-Leuven B-3001, Belgium
| | - Dirk Springael
- Division of Soil and Water Management, KU Leuven, Kasteelpark Arenberg 20, Heverlee-Leuven B-3001, Belgium
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Quantifying the Importance of the Rare Biosphere for Microbial Community Response to Organic Pollutants in a Freshwater Ecosystem. Appl Environ Microbiol 2017; 83:AEM.03321-16. [PMID: 28258138 DOI: 10.1128/aem.03321-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/01/2017] [Indexed: 01/01/2023] Open
Abstract
A single liter of water contains hundreds, if not thousands, of bacterial and archaeal species, each of which typically makes up a very small fraction of the total microbial community (<0.1%), the so-called "rare biosphere." How often, and via what mechanisms, e.g., clonal amplification versus horizontal gene transfer, the rare taxa and genes contribute to microbial community response to environmental perturbations represent important unanswered questions toward better understanding the value and modeling of microbial diversity. We tested whether rare species frequently responded to changing environmental conditions by establishing 20-liter planktonic mesocosms with water from Lake Lanier (Georgia, USA) and perturbing them with organic compounds that are rarely detected in the lake, including 2,4-dichlorophenoxyacetic acid (2,4-D), 4-nitrophenol (4-NP), and caffeine. The populations of the degraders of these compounds were initially below the detection limit of quantitative PCR (qPCR) or metagenomic sequencing methods, but they increased substantially in abundance after perturbation. Sequencing of several degraders (isolates) and time-series metagenomic data sets revealed distinct cooccurring alleles of degradation genes, frequently carried on transmissible plasmids, especially for the 2,4-D mesocosms, and distinct species dominating the post-enrichment microbial communities from each replicated mesocosm. This diversity of species and genes also underlies distinct degradation profiles among replicated mesocosms. Collectively, these results supported the hypothesis that the rare biosphere can serve as a genetic reservoir, which can be frequently missed by metagenomics but enables community response to changing environmental conditions caused by organic pollutants, and they provided insights into the size of the pool of rare genes and species.IMPORTANCE A single liter of water or gram of soil contains hundreds of low-abundance bacterial and archaeal species, the so called rare biosphere. The value of this astonishing biodiversity for ecosystem functioning remains poorly understood, primarily due to the fact that microbial community analysis frequently focuses on abundant organisms. Using a combination of culture-dependent and culture-independent (metagenomics) techniques, we showed that rare taxa and genes commonly contribute to the microbial community response to organic pollutants. Our findings should have implications for future studies that aim to study the role of rare species in environmental processes, including environmental bioremediation efforts of oil spills or other contaminants.
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Ricker N, Shen SY, Goordial J, Jin S, Fulthorpe RR. PacBio SMRT assembly of a complex multi-replicon genome reveals chlorocatechol degradative operon in a region of genome plasticity. Gene 2016; 586:239-47. [PMID: 27063562 DOI: 10.1016/j.gene.2016.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/14/2016] [Accepted: 04/05/2016] [Indexed: 01/03/2023]
Abstract
We have sequenced a Burkholderia genome that contains multiple replicons and large repetitive elements that would make it inherently difficult to assemble by short read sequencing technologies. We illustrate how the integrated long read correction algorithms implemented through the PacBio Single Molecule Real-Time (SMRT) sequencing technology successfully provided a de novo assembly that is a reasonable estimate of both the gene content and genome organization without making any further modifications. This assembly is comparable to related organisms assembled by more labour intensive methods. Our assembled genome revealed regions of genome plasticity for further investigation, one of which harbours a chlorocatechol degradative operon highly homologous to those previously identified on globally ubiquitous plasmids. In an ideal world, this assembly would still require experimental validation to confirm gene order and copy number of repeated elements. However, we submit that particularly in instances where a polished genome is not the primary goal of the sequencing project, PacBio SMRT sequencing provides a financially viable option for generating a biologically relevant genome estimate that can be utilized by other researchers for comparative studies.
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Affiliation(s)
- N Ricker
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1095 Military Trail, Scarborough, Ontario M1C 1A4, Canada
| | - S Y Shen
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1095 Military Trail, Scarborough, Ontario M1C 1A4, Canada
| | - J Goordial
- Department of Natural Resource Sciences, McGill University, Macdonald Campus, 21111 Lakeshore Rd., Sainte Anne de Bellevue, Quebec H9X 3V9, Canada
| | - S Jin
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1095 Military Trail, Scarborough, Ontario M1C 1A4, Canada
| | - R R Fulthorpe
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1095 Military Trail, Scarborough, Ontario M1C 1A4, Canada.
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