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A Synergistic Consortium Involved in rac-Dichlorprop Degradation as Revealed by DNA Stable Isotope Probing and Metagenomic Analysis. Appl Environ Microbiol 2021; 87:e0156221. [PMID: 34524896 DOI: 10.1128/aem.01562-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
rac-Dichlorprop, a commonly used phenoxyalkanoic acid herbicide, is frequently detected in environments and poses threats to environmental safety and human health. Microbial consortia are thought to play key roles in rac-dichlorprop degradation. However, the compositions of the microbial consortia involved in rac-dichlorprop degradation remain largely unknown. In this study, DNA stable isotope probing (SIP) and metagenomic analysis were integrated to reveal the key microbial consortium responsible for rac-dichlorprop degradation in a rac-dichlorprop-degrading enrichment. OTU340 (Sphingobium sp.) and OTU348 (Sphingopyxis sp.) were significantly enriched in the rac-[13C]dichlorprop-labeled heavy DNA fractions. A rac-dichlorprop degrader, Sphingobium sp. strain L3, was isolated from the enrichment by a traditional enrichment method but with additional supplementation of the antibiotic ciprofloxacin, which was instructed by metagenomic analysis of the associations between rac-dichlorprop degraders and antibiotic resistance genes. As revealed by functional profiling of the metagenomes of the heavy DNA, the genes rdpA and sdpA, involved in the initial degradation of the (R)- and (S)-enantiomers of dichlorprop, respectively, were mostly taxonomically assigned to Sphingobium species, indicating that Sphingopyxis species might harbor novel dichlorprop-degrading genes. In addition, taxonomically diverse bacterial genera such as Dyella, Sphingomonas, Pseudomonas, and Achromobacter were presumed to synergistically cooperate with the key degraders Sphingobium/Sphingopyxis for enhanced degradation of rac-dichlorprop. IMPORTANCE Understanding of the key microbial consortium involved in the degradation of the phenoxyalkanoic acid herbicide rac-dichlorprop is pivotal for design of synergistic consortia used for enhanced bioremediation of herbicide-contaminated sites. However, the composition of the microbial consortium and the interactions between community members during the biodegradation of rac-dichlorprop are unclear. In this study, DNA-SIP and metagenomic analysis were integrated to reveal that the metabolite 2,4-dichlorophenol degraders Dyella, Sphingomonas, Pseudomonas, and Achromobacter synergistically cooperated with the key degraders Sphingobium/Sphingopyxis for enhanced degradation of rac-dichlorprop. Our study provides new insights into the synergistic degradation of rac-dichlorprop at the community level and implies the existence of novel degrading genes for rac-dichlorprop in nature.
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Zhang L, Hang P, Zhou XY, Qiao WJ, Jiang JD. Enantioselective Catabolism of the Two Enantiomers of the Phenoxyalkanoic Acid Herbicide Dichlorprop by Sphingopyxis sp. DBS4. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:6967-6976. [PMID: 32530641 DOI: 10.1021/acs.jafc.0c01066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propanoic acid; DCPP], an important phenoxyalkanoic acid herbicide (PAAH), is extensively used in the form of racemic mixtures (Rac-DCPP), and the environmental fates of both DCPP enantiomers [(R)-DCPP and (S)-DCPP] mediated by microorganisms are of great concern. In this study, a bacterial strain Sphingopyxis sp. DBS4 was isolated from contaminated soil and was capable of utilizing both (R)-DCPP and (S)-DCPP as the sole carbon source for growth. Strain DBS4 preferentially catabolized (S)-DCPP as compared to (R)-DCPP. The optimal conditions for Rac-DCPP degradation by strain DBS4 were 30 °C and pH 7.0. In addition to Rac-DCPP, other PAAHs such as (RS)-2-(4-chloro-2-methylphenoxy)propanoic acid, 2,4-dichlorophenoxyacetic acid, 4-chloro-2-methylphenoxyacetic acid, and 2,4-dichlorophenoxyacetic acid butyl ester could also be catabolized by strain DBS4. Bioremediation of Rac-DCPP-contaminated soil by inoculation of strain DBS4 exhibited an effective removal of both (R)-DCPP and (S)-DCPP from the soil. Due to its broad substrate spectrum, strain DBS4 showed great potential in the bioremediation of PAAH-contaminated sites.
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Affiliation(s)
- Long Zhang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
- College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Ping Hang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Xi-Yi Zhou
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Wen-Jing Qiao
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Jian-Dong Jiang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, 210095 Nanjing, China
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Establishment of Bacterial Herbicide Degraders in a Rapid Sand Filter for Bioremediation of Phenoxypropionate-Polluted Groundwater. Appl Environ Microbiol 2015; 82:878-87. [PMID: 26590282 DOI: 10.1128/aem.02600-15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/16/2015] [Indexed: 02/01/2023] Open
Abstract
In this study, we investigated the establishment of natural bacterial degraders in a sand filter treating groundwater contaminated with the phenoxypropionate herbicides (RS)-2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP) and (RS)-2-(2,4-dichlorophenoxy)propanoic acid (DCPP) and the associated impurity/catabolite 4-chlorophenoxypropanoic acid (4-CPP). A pilot facility was set up in a contaminated landfill site. Anaerobic groundwater was pumped up and passed through an aeration basin and subsequently through a rapid sand filter, which is characterized by a short residence time of the water in the filter. For 3 months, the degradation of DCPP, MCPP, and 4-CPP in the sand filter increased to 15 to 30% of the inlet concentration. A significant selection for natural bacterial herbicide degraders also occurred in the sand filter. Using a most-probable-number (MPN) method, we found a steady increase in the number of culturable phenoxypropionate degraders, reaching approximately 5 × 10(5) degraders per g sand by the end of the study. Using a quantitative PCR targeting the two phenoxypropionate degradation genes, rdpA and sdpA, encoding stereospecific dioxygenases, a parallel increase was observed, but with the gene copy numbers being about 2 to 3 log units higher than the MPN. In general, the sdpA gene was more abundant than the rdpA gene, and the establishment of a significant population of bacteria harboring sdpA occurred faster than the establishment of an rdpA gene-carrying population. The identities of the specific herbicide degraders in the sand filter were assessed by Illumina MiSeq sequencing of 16S rRNA genes from sand filter samples and from selected MPN plate wells. We propose a list of potential degrader bacteria involved in herbicide degradation, including representatives belonging to the Comamonadaceae and Sphingomonadales.
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Han L, Zhao D, Li C. Isolation and 2,4-D-degrading characteristics of Cupriavidus campinensis BJ71. Braz J Microbiol 2015; 46:433-41. [PMID: 26273258 PMCID: PMC4507535 DOI: 10.1590/s1517-838246220140211] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 10/30/2014] [Indexed: 11/22/2022] Open
Abstract
An indigenous bacterial strain capable of utilizing 2,4-dichlorophenoxyacetic acid as the sole carbon and energy source was isolated from a soil used for grown wheat with a long-term history of herbicide use in Beijing, China. The strain BJ71 was identified as Cupriavidus campinensis based on its 16S rRNA sequence analysis and morphological, physiological, and biochemical characteristics. The degradation characteristics of strain BJ71 were evaluated. The optimal conditions for 2,4-D degradation were as follows: pH 7.0, 30 °C, 3% (v/v) inoculum size, and an initial 2,4-D concentration of 350 mg L(-1). Up to 99.57% of the 2,4-D was degraded under optimal conditions after 6 days of incubation. Strain BJ71 was also able to degrade quizalofop and fluroxypyr. This is the first report of a 2,4-D-degrader containing tfdA gene that can utilize these two herbicides. In a biodegradation experiment, 87.13% and 42.53% of 2,4-D (initial concentration, 350 mg kg(-1)) was degraded in non-sterile and sterilized soil inoculated with BJ71, respectively, after 14 days. The 2,4-D degradation was more rapid in a soil microcosm including BJ71 than in a soil microcosm without BJ71. These results indicate that strain BJ71 is a potential candidate for the bioremediation of soil contaminated with the herbicide 2,4-D.
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Affiliation(s)
- Lizhen Han
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region, Ministry of Education, Guiyang, China, The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region, Ministry of Education, Guiyang, China. ; Guizhou University, College of Life Sciences, Guizhou University, Guiyang, China, College of Life Sciences, Guizhou University, Guiyang, China. ; Guizhou University, Institute of Agro-Bioengineering, Guizhou University, Guiyang, China, Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Degang Zhao
- The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region, Ministry of Education, Guiyang, China, The Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region, Ministry of Education, Guiyang, China. ; Guizhou University, College of Life Sciences, Guizhou University, Guiyang, China, College of Life Sciences, Guizhou University, Guiyang, China. ; Guizhou University, Institute of Agro-Bioengineering, Guizhou University, Guiyang, China, Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
| | - Cuicui Li
- Guizhou University, College of Life Sciences, Guizhou University, Guiyang, China, College of Life Sciences, Guizhou University, Guiyang, China. ; Guizhou University, Institute of Agro-Bioengineering, Guizhou University, Guiyang, China, Institute of Agro-Bioengineering, Guizhou University, Guiyang, China
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16S rRNA gene phylogeny and tfdA gene analysis of 2,4-D-degrading bacteria isolated in China. World J Microbiol Biotechnol 2014; 30:2567-76. [PMID: 24898178 DOI: 10.1007/s11274-014-1680-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 05/27/2014] [Indexed: 10/25/2022]
Abstract
Twenty-two 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterial isolates were collected from agricultural soils at three sites in China. Sequence analysis of the 16S rRNA genes indicated that the isolates were phylogenetically grouped into four categories: Ochrobactrum anthropi, in the Alpha- class of the phylum Proteobacteria (3 out of 22 isolates), Cupriavidus sp., of the Betaproteobacteria (3 out of 22), Pseudomonas sp. and Stenotrophomonas sp., which are Gammaproteobacteria (7 out of 22), and Bacillus sp., of the phylum Firmicutes (9 out of 22). Primers were designed to amplify the conserved domain of tfdA, which is known to be involved in the degradation of 2,4-D. Results showed that the tfdA genes of all 22 strains were most similar to that of Cupriavidus necator JMP134, which belongs to the 2,4-D/α-ketoglutarate dioxygenase TfdA protein family, indicating that the JMP134-type tfdA gene is likely to be almost universal among the 2,4-D-degrading bacteria isolated from China. Degradation abilities of these 22 strains were investigated in assays using 2,4-D as the sole source of carbon and energy. Thirteen strains degraded >60 % of the available 2,4-D (500 mg l(-1)) over a 1-week incubation period, while a further nine Bacillus sp. strains degraded 50-81 % of the available 2,4-D. None of these nine strains degraded other selected herbicides, such as mecoprop, 2-methyl-4-chlorophenoxyacetic acid, quizalofop, and fluroxypyr. This is the first report of 2,4-D-degradation by Bacilli.
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Qiu S, Gözdereliler E, Weyrauch P, Lopez ECM, Kohler HPE, Sørensen SR, Meckenstock RU, Elsner M. Small 13C/ 12C Fractionation Contrasts with Large Enantiomer Fractionation in Aerobic Biodegradation of Phenoxy Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:5501-11. [PMID: 24708181 DOI: 10.1021/es405103g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Shiran Qiu
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Erkin Gözdereliler
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Philip Weyrauch
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Eva C. Magana Lopez
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Hans-Peter E. Kohler
- Swiss Federal Institute of Aquatic Science and Technology (Eawag), Überlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - Sebastian R. Sørensen
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350 Copenhagen K, Denmark
| | - Rainer U. Meckenstock
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstadter Landstr. 1, 85764 Neuherberg, Germany
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Golchoubian H, Nazari O, Mohseni M. Synthesis, crystal structure, and antimicrobial activity of bis((2-(2-aminoethyl)imino-3-butanone oxime)copper(II) perchlorate. J COORD CHEM 2014. [DOI: 10.1080/00958972.2014.913135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
| | - Omeleila Nazari
- Department of Chemistry, University of Mazandaran, Babol-sar, Iran
| | - Mojtaba Mohseni
- Department of Molecular and Cell Biology, University of Mazandaran, Babol-sar, Iran
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Zakaria D, Lappin-Scott H, Burton S, Whitby C. Bacterial diversity in soil enrichment cultures amended with 2 (2-methyl-4-chlorophenoxy) propionic acid (mecoprop). Environ Microbiol 2008; 9:2575-87. [PMID: 17803781 DOI: 10.1111/j.1462-2920.2007.01375.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Summary The tfdA gene encodes for an alpha-ketoglutarate-dependent dioxygenase enzyme which catalyses the first step of the degradation of phenoxyalkanoic acid herbicides such as 2 (2-methyl-4-chlorophenoxy) propionic acid (mecoprop). The bacterial diversity of soil enrichment cultures containing mecoprop was examined by Denaturing Gradient Gel Electrophoresis (DGGE) and clone libraries of both 16S rRNA genes and tfdA genes. The 16S rRNA gene sequences were diverse and clustered with either the Beta- or Gammaproteobacteria. The 16S rRNA gene sequence from a bacterial strain isolated from an enrichment culture, grown on R-mecoprop, which represented a dominant band in the DGGE profiles, had a high 16S rRNA sequence identity (100%) to Burkholderia glathei. This is the first report that B. glathei is implicated in mecoprop degradation. PCR amplification of the tfdA genes detected class III tfdA genes only, and no class I or class II tfdA sequences were detected. To understand the genes involved the degradation of specific mecoprop (R-) and (S-) enantiomers, oligonucleotide probes targeting the tfdA, rdpA, sdpA and cadA genes were hybridized to DNA extracted from enrichment cultures grown on either R-mecoprop or (R/S) racemic mecoprop. Strong hybridization signals were obtained with sdpA and tfdA probes using DNA extracted from cultures grown on racemic mecoprop. A strong hybridization signal was also obtained with the rdpA probe with DNA extracted from the cultures grown on R-mecoprop. This suggests the rdpA gene is involved in R-mecoprop degradation while tfdA, sdpA and cadA genes are involved in the degradation of both R- and S-mecoprop.
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Affiliation(s)
- Dalia Zakaria
- School of BioSciences, Prince of Wales Road, University of Exeter, Exeter EX4 4PS, UK
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Campillos M, von Mering C, Jensen LJ, Bork P. Identification and analysis of evolutionarily cohesive functional modules in protein networks. Genome Res 2006; 16:374-82. [PMID: 16449501 PMCID: PMC1415216 DOI: 10.1101/gr.4336406] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The increasing number of sequenced genomes makes it possible to infer the evolutionary history of functional modules, i.e., groups of proteins that contribute jointly to the same cellular function in a given species. Here we identify and analyze those prokaryotic functional modules, whose composition remains largely unchanged during evolution, and study their properties. Such "cohesive" modules have a large number of internal functional connections, encode genes that tend to be in close proximity in prokaryotic genomes, and correspond to physical complexes or complex functional systems like the flagellar apparatus. Cohesive modules are enriched in processes such as energy and amino acid metabolism, cell motility, and intracellular trafficking, or secretion. By grouping genes into modules we achieve a more precise estimate of their age and find that the young modules are often horizontally transferred between species and are enriched in functions involved in interactions with the environment, implying that they play an important role in the adaptation of species to new environments.
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Affiliation(s)
- Mónica Campillos
- The European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
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Schleinitz KM, Kleinsteuber S, Vallaeys T, Babel W. Localization and characterization of two novel genes encoding stereospecific dioxygenases catalyzing 2(2,4-dichlorophenoxy)propionate cleavage in Delftia acidovorans MC1. Appl Environ Microbiol 2004; 70:5357-65. [PMID: 15345421 PMCID: PMC520888 DOI: 10.1128/aem.70.9.5357-5365.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two novel genes, rdpA and sdpA, encoding the enantiospecific alpha-ketoglutarate dependent dioxygenases catalyzing R,S-dichlorprop cleavage in Delftia acidovorans MC1 were identified. Significant similarities to other known genes were not detected, but their deduced amino acid sequences were similar to those of other alpha-ketoglutarate dioxygenases. RdpA showed 35% identity with TauD of Pseudomonas aeruginosa, and SdpA showed 37% identity with TfdA of Ralstonia eutropha JMP134. The functionally important amino acid sequence motif HX(D/E)X(23-26)(T/S)X(114-183)HX(10-13)R/K, which is highly conserved in group II alpha-ketoglutarate-dependent dioxygenases, was present in both dichlorprop-cleaving enzymes. Transposon mutagenesis of rdpA inactivated R-dichlorprop cleavage, indicating that it was a single-copy gene. Both rdpA and sdpA were located on the plasmid pMC1 that also carries the lower pathway genes. Sequencing of a 25.8-kb fragment showed that the dioxygenase genes were separated by a 13.6-kb region mainly comprising a Tn501-like transposon. Furthermore, two copies of a sequence similar to IS91-like elements were identified. Hybridization studies comparing the wild-type plasmid and that of the mutant unable to cleave dichlorprop showed that rdpA and sdpA were deleted, whereas the lower pathway genes were unaffected, and that deletion may be caused by genetic rearrangements of the IS91-like elements. Two other dichlorprop-degrading bacterial strains, Rhodoferax sp. strain P230 and Sphingobium herbicidovorans MH, were shown to carry rdpA genes of high similarity to rdpA from strain MC1, but sdpA was not detected. This suggested that rdpA gene products are involved in the degradation of R-dichlorprop in these strains.
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Affiliation(s)
- Kathleen M Schleinitz
- Department of Environmental Microbiology, UFZ Centre for Environmental Research Leipzig-Halle, Leipzig, Germany. [corrected]
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Smejkal CW, Seymour FA, Burton SK, Lappin-Scott HM. Characterisation of bacterial cultures enriched on the chlorophenoxyalkanoic acid herbicides 4-(2,4-dichlorophenoxy) butyric acid and 4-(4-chloro-2-methylphenoxy) butyric acid. J Ind Microbiol Biotechnol 2003; 30:561-7. [PMID: 14513383 DOI: 10.1007/s10295-003-0086-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2002] [Accepted: 07/05/2003] [Indexed: 10/26/2022]
Abstract
The aim of this study was to enrich and characterise bacterial consortia from soils around a herbicide production plant through their capability to degrade the herbicides 4-(2,4-dichlorophenoxy) butyric acid (2,4-DB) and 4-(4-chloro-2-methylphenoxy) butyric acid (MCPB). Partial 16S rRNA gene sequencing revealed members of the genera Stenotrophomonas, Brevundimonas, Pseudomonas, and Ochrobactrum in the 2,4-DB- and MCPB-degrading communities. The degradation of 2,4-DB and MCPB was facilitated by the combined activities of the community members. Some of the members were able to utilise other herbicides from the family of chlorophenoxyalkanoic acids. During degradation of 2,4-DB and MCPB, phenol intermediates were detected, indicating ether cleavage of the side chain as the initial step responsible for the breakdown. This was also verified using an indicator medium. Repeated attempts to amplify putatively conserved tfd genes by PCR indicated the absence of tfd genes among the consortia members. First step cleavage of the chlorophenoxybutyric acid herbicides is by ether cleavage in bacteria and is encoded by divergent or different tfd gene types. The isolation of mixed cultures capable of degrading 2,4-DB and MCPB will aid future investigations to determine both the metabolic route for dissimilation and the fate of these herbicides in natural environments.
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Affiliation(s)
- C W Smejkal
- School of Biological Sciences, University of Exeter, Exeter, Devon, EX4 4PS, UK
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Top EM, Springael D. The role of mobile genetic elements in bacterial adaptation to xenobiotic organic compounds. Curr Opin Biotechnol 2003; 14:262-9. [PMID: 12849778 DOI: 10.1016/s0958-1669(03)00066-1] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Retrospective studies clearly indicate that mobile genetic elements (MGEs) play a major role in the in situ spread and even de novo construction of catabolic pathways in bacteria, allowing bacterial communities to rapidly adapt to new xenobiotics. The construction of novel pathways seems to occur by an assembly process that involves horizontal gene transfer: different appropriate genes or gene modules that encode different parts of the novel pathway are recruited from phylogenetically related or distant hosts into one single host. Direct evidence for the importance of catabolic MGEs in bacterial adaptation to xenobiotics stems from observed correlations between catabolic gene transfer and accelerated biodegradation in several habitats and from studies that monitor catabolic MGEs in polluted sites.
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Affiliation(s)
- Eva M Top
- Department of Biological Sciences, 347 Life Sciences Building South, University of Idaho, Moscow, ID 83844-3051, USA.
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Parales RE, Bruce NC, Schmid A, Wackett LP. Biodegradation, biotransformation, and biocatalysis (b3). Appl Environ Microbiol 2002; 68:4699-709. [PMID: 12324310 PMCID: PMC126401 DOI: 10.1128/aem.68.10.4699-4709.2002] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- R E Parales
- Department of Microbiology and Center for Biocatalysis and Bioprocessing, The University of Iowa, Iowa City, Iowa, USA.
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