1
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Kamagata Y. Cultivating the unseen: Lessons from James Tiedje. MLIFE 2023; 2:217-223. [PMID: 38817816 PMCID: PMC10989887 DOI: 10.1002/mlf2.12083] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/12/2023] [Accepted: 07/22/2023] [Indexed: 06/01/2024]
Affiliation(s)
- Yoichi Kamagata
- National Institute of Advanced and Industrial Science and Technology (AIST)TsukubaJapan
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2
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Łomża P, Krucoń T, Tabernacka A. Potential of Microbial Communities to Perform Dehalogenation Processes in Natural and Anthropogenically Modified Environments-A Metagenomic Study. Microorganisms 2023; 11:1702. [PMID: 37512875 PMCID: PMC10385969 DOI: 10.3390/microorganisms11071702] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/15/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Halogenated organic compounds (HOCs) pose a serious problem for the environment. Many are highly toxic and accumulate both in soil and in organisms. Their biological transformation takes place by dehalogenation, in which the halogen substituents are detached from the carbon in the organic compound by enzymes produced by microorganisms. This increases the compounds' water solubility and bioavailability, reduces toxicity, and allows the resulting compound to become more susceptible to biodegradation. The microbial halogen cycle in soil is an important part of global dehalogenation processes. The aim of the study was to examine the potential of microbial communities inhabiting natural and anthropogenically modified environments to carry out the dehalogenation process. The potential of microorganisms was assessed by analyzing the metagenomes from a natural environment (forest soils) and from environments subjected to anthropopression (agricultural soil and sludge from wastewater treatment plants). Thirteen genes encoding enzymes with dehalogenase activity were identified in the metagenomes of both environments, among which, 2-haloacid dehalogenase and catechol 2,3-dioxygenase were the most abundant genes. Comparative analysis, based on comparing taxonomy, identified genes, total halogens content and content of DDT derivatives, demonstrated the ability of microorganisms to transform HOCs in both environments, indicating the presence of these compounds in the environment for a long period of time and the adaptive need to develop mechanisms for their detoxification. Metagenome analyses and comparative analyses indicate the genetic potential of microorganisms of both environments to carry out dehalogenation processes, including dehalogenation of anthropogenic HOCs.
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Affiliation(s)
- Pola Łomża
- Department of Biology, Faculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology, 20 Nowowiejska Street, 00-653 Warsaw, Poland
| | - Tomasz Krucoń
- Department of Environmental Microbiology and Biotechnology, Faculty of Biology, University of Warsaw, 1 Miecznikowa Street, 02-089 Warsaw, Poland
| | - Agnieszka Tabernacka
- Department of Biology, Faculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology, 20 Nowowiejska Street, 00-653 Warsaw, Poland
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3
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Wilms W, Woźniak-Karczewska M, Niemczak M, Parus A, Frankowski R, Wolko Ł, Czarny J, Piotrowska-Cyplik A, Zgoła-Grześkowiak A, Heipieper HJ, Chrzanowski Ł. 2,4-D versus 2,4-D based ionic liquids: Effect of cation on herbicide biodegradation, tfdA genes abundance and microbiome changes during soil bioaugmentation. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131209. [PMID: 36940526 DOI: 10.1016/j.jhazmat.2023.131209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/22/2023] [Accepted: 03/12/2023] [Indexed: 05/03/2023]
Abstract
The commercial formulations of herbicides rely on surfactants which increase the efficiency of active substance. Herbicidal ionic liquids (ILs), in which cationic surfactants are combined with herbicidal anions, allow for additives' reduction and ensure very good herbicide performance with lower doses. We aimed to test the impact of synthetic and natural cations on biological degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). Although primary biodegradation was high, the mineralization in agricultural soil indicated incomplete conversion of ILs to CO2. Even the introduction of naturally-derived cations resulted in an increase in the herbicide's half-lives - from 32 days for [Na][2,4-D] to 120 days for [Chol][2,4-D] and 300 days for the synthetic tetramethylammonium derivative [TMA][2,4-D]. Bioaugmentation with 2,4-D-degrading strains improves the herbicides' degradation, which was reflected by higher abundance of tfdA genes. Microbial community analysis confirmed that hydrophobic cationic surfactants, even those based on natural compounds, played a negative role on microbial biodiversity. Our study provides a valuable indication for further research related to the production of a new generation of environmentally friendly compounds. Moreover, the results shed a new light on the ionic liquids as independent mixtures of ions in the environment, as opposed to treating them as new type of environmental pollutants.
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Affiliation(s)
- Wiktoria Wilms
- Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan, Poland
| | | | - Michał Niemczak
- Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan, Poland
| | - Anna Parus
- Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan, Poland
| | - Robert Frankowski
- Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan, Poland
| | - Łukasz Wolko
- Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, Dojazd 11, 60-632 Poznan, Poland
| | - Jakub Czarny
- Institute of Forensic Genetics, Al. Mickiewicza 3/4, 85-071 Bydgoszcz, Poland
| | - Agnieszka Piotrowska-Cyplik
- Department of Food Technology of Plant Origin, Poznan University of Life Sciences, Wojska Polskiego 31, 60-624 Poznan, Poland
| | | | - Hermann J Heipieper
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Łukasz Chrzanowski
- Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan, Poland; Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Permoserstraße 15, 04318 Leipzig, Germany
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4
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Wang Y, Tian YS, Gao JJ, Xu J, Li ZJ, Fu XY, Han HJ, Wang LJ, Zhang WH, Deng YD, Qian C, Zuo ZH, Wang B, Peng RH, Yao QH. Complete biodegradation of the oldest organic herbicide 2,4-Dichlorophenoxyacetic acid by engineering Escherichia coli. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131099. [PMID: 36868133 DOI: 10.1016/j.jhazmat.2023.131099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/23/2023] [Accepted: 02/25/2023] [Indexed: 06/18/2023]
Abstract
After nearly 80 years of extensive application, the oldest organic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has caused many problems of environmental pollution and ecological deterioration. Bioremediation is an ideal method for pollutant treatment. However, difficult screening and preparation of efficient degradation bacteria have largely hindered its application in 2,4-D remediation. We have created a novel engineering Escherichia coli with a reconstructed complete degradation pathway of 2,4-D to solve the problem of screening highly efficient degradation bacteria in this study. The results of fluorescence quantitative PCR demonstrated that all nine genes in the degradation pathway were successfully expressed in the engineered strain. The engineered strains can quickly and completely degrade 0.5 mM 2, 4-D within 6 h. Inspiring, the engineered strains grew with 2,4-D as the sole carbon source. By using the isotope tracing method, the metabolites of 2,4-D were found incorporated into the tricarboxylic acid cycle in the engineering strain. Scanning electron microscopy showed that 2,4-D had less damage on the engineered bacteria than the wild-type strain. Engineered strain can also rapidly and completely remedy 2,4-D pollution in natural water and soil. Assembling the metabolic pathways of pollutants through synthetic biology was an effective method to create pollutant-degrading bacteria for bioremediation.
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Affiliation(s)
- Yu Wang
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Yong-Sheng Tian
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Jian-Jie Gao
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Jing Xu
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Zhen-Jun Li
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Xiao-Yan Fu
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Hong-Juan Han
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Li-Juan Wang
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Wen-Hui Zhang
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Yong-Dong Deng
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Cen Qian
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Zhi-Hao Zuo
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Bo Wang
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China.
| | - Ri-He Peng
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China.
| | - Quan-Hong Yao
- Shanghai Key laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China.
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5
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Kitagawa W, Hata M. Development of Efficient Genome-Reduction Tool Based on Cre/ loxP System in Rhodococcus erythropolis. Microorganisms 2023; 11:microorganisms11020268. [PMID: 36838232 PMCID: PMC9959502 DOI: 10.3390/microorganisms11020268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023] Open
Abstract
Rhodococcus has been extensively studied for its excellent ability to degrade artificial chemicals and its capability to synthesize biosurfactants and antibiotics. In recent years, studies have attempted to use Rhodococcus as a gene expression host. Various genetic tools, such as plasmid vectors, transposon mutagenesis, and gene disruption methods have been developed for use in Rhodococcus; however, no effective method has been reported for performing large-size genome reduction. Therefore, the present study developed an effective plasmid-curing method using the levansucrase-encoding sacB gene and a simple two-step genome-reduction method using a modified Cre/loxP system. For the results, R. erythropolis JCM 2895 was used as the model; a mutant strain that cured all four plasmids and deleted seven chromosomal regions was successfully obtained in this study. The total DNA deletion size was >600 kb, which corresponds mostly to 10% of the genome size. Using this method, a genome-structure-stabilized and unfavorable gene/function-lacking host strain can be created in Rhodococcus. This genetic tool will help develop and improve Rhodococcus strains for various industrial and environmental applications.
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Affiliation(s)
- Wataru Kitagawa
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST), Sapporo 062-8517, Japan
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
- Correspondence:
| | - Miyako Hata
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST), Sapporo 062-8517, Japan
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6
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The structure-function relationship of bacterial transcriptional regulators as a target for enhanced biodegradation of aromatic hydrocarbons. Microbiol Res 2022; 262:127087. [DOI: 10.1016/j.micres.2022.127087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 06/03/2022] [Accepted: 06/03/2022] [Indexed: 11/20/2022]
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7
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Cheng M, Chen D, Parales RE, Jiang J. Oxygenases as Powerful Weapons in the Microbial Degradation of Pesticides. Annu Rev Microbiol 2022; 76:325-348. [PMID: 35650666 DOI: 10.1146/annurev-micro-041320-091758] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oxygenases, which catalyze the reductive activation of O2 and incorporation of oxygen atoms into substrates, are widely distributed in aerobes. They function by switching the redox states of essential cofactors that include flavin, heme iron, Rieske non-heme iron, and Fe(II)/α-ketoglutarate. This review summarizes the catalytic features of flavin-dependent monooxygenases, heme iron-dependent cytochrome P450 monooxygenases, Rieske non-heme iron-dependent oxygenases, Fe(II)/α-ketoglutarate-dependent dioxygenases, and ring-cleavage dioxygenases, which are commonly involved in pesticide degradation. Heteroatom release (hydroxylation-coupled hetero group release), aromatic/heterocyclic ring hydroxylation to form ring-cleavage substrates, and ring cleavage are the main chemical fates of pesticides catalyzed by these oxygenases. The diversity of oxygenases, specificities for electron transport components, and potential applications of oxygenases are also discussed. This article summarizes our current understanding of the catalytic mechanisms of oxygenases and a framework for distinguishing the roles of oxygenases in pesticide degradation. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Minggen Cheng
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs and Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China;
| | - Dian Chen
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Rebecca E Parales
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California, Davis, California, USA
| | - Jiandong Jiang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs and Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China;
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8
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Hayashi S, Tanaka S, Takao S, Kobayashi S, Suyama K, Itoh K. Multiple Gene Clusters and Their Role in the Degradation of Chlorophenoxyacetic Acids in Bradyrhizobium sp. RD5-C2 Isolated from Non-Contaminated Soil. Microbes Environ 2021; 36:ME21016. [PMID: 34511574 PMCID: PMC8446748 DOI: 10.1264/jsme2.me21016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 08/10/2021] [Indexed: 11/12/2022] Open
Abstract
Bradyrhizobium sp. RD5-C2, isolated from soil that is not contaminated with 2,4-dichlorophenoxyacetic acid (2,4-D), degrades the herbicides 2,4-D and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). It possesses tfdAα and cadA (designated as cadA1), which encode 2,4-D dioxygenase and the oxygenase large subunit, respectively. In the present study, the genome of Bradyrhizobium sp. RD5-C2 was sequenced and a second cadA gene (designated as cadA2) was identified. The two cadA genes belonged to distinct clusters comprising the cadR1A1B1K1C1 and cadR2A2B2C2K2S genes. The proteins encoded by the cad1 cluster exhibited high amino acid sequence similarities to those of other 2,4-D degraders, while Cad2 proteins were more similar to those of non-2,4-D degraders. Both cad clusters were capable of degrading 2,4-D and 2,4,5-T when expressed in non-2,4-D-degrading Bradyrhizobium elkanii USDA94. To examine the contribution of each degradation gene cluster to the degradation activity of Bradyrhizobium sp. RD5-C2, cadA1, cadA2, and tfdAα deletion mutants were constructed. The cadA1 deletion resulted in a more significant decrease in the ability to degrade chlorophenoxy compounds than the cadA2 and tfdAα deletions, indicating that degradation activity was primarily governed by the cad1 cluster. The results of a quantitative reverse transcription-PCR analysis suggested that exposure to 2,4-D and 2,4,5-T markedly up-regulated cadA1 expression. Collectively, these results indicate that the cad1 cluster plays an important role in the degradation of Bradyrhizobium sp. RD5-C2 due to its high expression.
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Affiliation(s)
- Shohei Hayashi
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690–8504, Japan
| | - Sho Tanaka
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690–8504, Japan
| | - Soichiro Takao
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690–8504, Japan
| | - Shinnosuke Kobayashi
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690–8504, Japan
| | - Kousuke Suyama
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690–8504, Japan
| | - Kazuhito Itoh
- Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690–8504, Japan
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Chavez Rodriguez L, Ingalls B, Schwarz E, Streck T, Uksa M, Pagel H. Gene-Centric Model Approaches for Accurate Prediction of Pesticide Biodegradation in Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13638-13650. [PMID: 33064475 DOI: 10.1021/acs.est.0c03315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pesticides are widely used in agriculture despite their negative impact on ecosystems and human health. Biogeochemical modeling facilitates the mechanistic understanding of microbial controls on pesticide turnover in soils. We propose to inform models of coupled microbial dynamics and pesticide turnover with measurements of the abundance and expression of functional genes. To assess the advantages of informing models with genetic data, we developed a novel "gene-centric" model and compared model variants of differing structural complexity against a standard biomass-based model. The models were calibrated and validated using data from two batch experiments in which the degradation of the pesticides dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) were observed in soil. When calibrating against data on pesticide mineralization, the gene-centric and biomass-based models performed equally well. However, accounting for pesticide-triggered gene regulation allows improved performance in capturing microbial dynamics and in predicting pesticide mineralization. This novel modeling approach also reveals a hysteretic relationship between pesticide degradation rates and gene expression, implying that the biodegradation performance in soils cannot be directly assessed by measuring the expression of functional genes. Our gene-centric model provides an effective approach for exploiting molecular biology data to simulate pesticide degradation in soils.
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Affiliation(s)
- Luciana Chavez Rodriguez
- Institute of Soil Science and Land Evaluation, Biogeophysics Section, University of Hohenheim, Stuttgart, Germany
| | - Brian Ingalls
- Department of Applied Mathematics, University of Waterloo, Waterloo, ON, Canada
| | - Erik Schwarz
- Institute of Soil Science and Land Evaluation, Biogeophysics Section, University of Hohenheim, Stuttgart, Germany
| | - Thilo Streck
- Institute of Soil Science and Land Evaluation, Biogeophysics Section, University of Hohenheim, Stuttgart, Germany
| | - Marie Uksa
- Institute of Soil Science and Land Evaluation, Soil Biology Section, University of Hohenheim, Stuttgart, Germany
| | - Holger Pagel
- Institute of Soil Science and Land Evaluation, Biogeophysics Section, University of Hohenheim, Stuttgart, Germany
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OnfD, an AraC-Type Transcriptional Regulator Encoded by Rhizobium tropici CIAT 899 and Involved in Nod Factor Synthesis and Symbiosis. Appl Environ Microbiol 2020; 86:AEM.01297-20. [PMID: 32709725 PMCID: PMC7499043 DOI: 10.1128/aem.01297-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023] Open
Abstract
Rhizobium tropici CIAT 899 is a broad-host-range rhizobial strain that establishes symbiotic interactions with legumes and tolerates different environmental stresses such as heat, acidity, or salinity. This rhizobial strain produces a wide variety of symbiotically active nodulation factors (NF) induced not only by the presence of plant-released flavonoids but also under osmotic stress conditions through the LysR-type transcriptional regulators NodD1 (flavonoids) and NodD2 (osmotic stress). However, the activation of NodD2 under high-osmotic-stress conditions remains elusive. Here, we have studied the role of a new AraC-type regulator (named as OnfD) in the symbiotic interaction of R. tropici CIAT 899 with Phaseolus vulgaris and Lotus plants. We determined that OnfD is required under salt stress conditions for the transcriptional activation of the nodulation genes and therefore the synthesis and export of NF, which are required for a successful symbiosis with P. vulgaris Moreover, using bacterial two-hybrid analysis, we demonstrated that the OnfD and NodD2 proteins form homodimers and OnfD/NodD2 form heterodimers, which could be involved in the production of NF in the presence of osmotic stress conditions since both regulators are required for NF synthesis in the presence of salt. A structural model of OnfD is presented and discussed.IMPORTANCE The synthesis and export of rhizobial NF are mediated by a conserved group of LysR-type regulators, the NodD proteins. Here, we have demonstrated that a non-LysR-type regulator, an AraC-type protein, is required for the transcriptional activation of symbiotic genes and for the synthesis of symbiotically active NF under salt stress conditions.
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Ritcharoon B, Sallabhan R, Toewiwat N, Mongkolsuk S, Loprasert S. Detection of 2,4-dichlorophenoxyacetic acid herbicide using a FGE-sulfatase based whole-cell Agrobacterium biosensor. J Microbiol Methods 2020; 175:105997. [PMID: 32645339 DOI: 10.1016/j.mimet.2020.105997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 11/29/2022]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) has been widely used as a herbicide for agricultural purposes. Currently, the available methods for detecting 2,4-D require multi-step sample preparations and expensive instruments. The use of a whole cell biosensor is an interesting approach that is straightforward and simple to use. In this study, we constructed a genetic-based Agrobacterium tumefaciens biosensor based on a cadA promoter and cadR regulator from Bradyrhizobium sp. strain HW13 (2,4-D degrader) with a formylglycine generating enzyme (FGE)-sulfatase as the reporter gene. The performance of the biosensor was further improved through direct evolution of the cadR activator. The detection limit of cadR mutants for phenoxyacetic acid herbicides including 2,4-D and 4-Chlorophenoxyacetic acid (4-CPAA) were 1.56 μM (an eight-fold improvement compared to wild-type CadR). The biosensor could detect 2,4-D contamination in environmental samples without encountering interference from other complex compounds. The Agrobacterium biosensor was also stable after storing in a simple Luria-Bertani (LB) medium at 4 °C for 30 days where the activity remained at 82% when exposed to 100 μM of 2,4-D. This novel biosensor, with its high stability under simple storage conditions, exhibits promising potential to be used as an inexpensive and easy-to-use tool to screen for 2,4-D contamination in environmental sources.
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Affiliation(s)
- Benjarat Ritcharoon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Ratiboot Sallabhan
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Neal Toewiwat
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, Ministry of Education, Bangkok 10400, Thailand
| | - Suvit Loprasert
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, Ministry of Education, Bangkok 10400, Thailand.
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12
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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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Cabrera MÁ, Márquez SL, Quezada CP, Osorio MI, Castro-Nallar E, González-Nilo FD, Pérez-Donoso JM. Biotransformation of 2,4,6-Trinitrotoluene by Pseudomonas sp. TNT3 isolated from Deception Island, Antarctica. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 262:113922. [PMID: 32443190 DOI: 10.1016/j.envpol.2020.113922] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 12/11/2019] [Accepted: 01/05/2020] [Indexed: 06/11/2023]
Abstract
2,4,6-Trinitrotoluene (TNT) is a nitroaromatic explosive, highly toxic and mutagenic for organisms. In this study, we report for the first time the screening and isolation of TNT-degrading bacteria from Antarctic environmental samples with potential use as bioremediation agents. Ten TNT-degrading bacterial strains were isolated from Deception Island. Among them, Pseudomonas sp. TNT3 was selected as the best candidate since it showed the highest tolerance, growth, and TNT biotransformation capabilities. Our results showed that TNT biotransformation involves the reduction of the nitro groups. Additionally, Pseudomonas sp. TNT3 was capable of transforming 100 mg/L TNT within 48 h at 28 °C, showing higher biotransformation capability than Pseudomonas putida KT2440, a known TNT-degrading bacterium. Functional annotation of Pseudomonas sp. TNT3 genome revealed a versatile set of molecular functions involved in xenobiotic degradation pathways. Two putative xenobiotic reductases (XenA_TNT3 and XenB_TNT3) were identified by means of homology searches and phylogenetic relationships. These enzymes were also characterized at molecular level using homology modelling and molecular dynamics simulations. Both enzymes share different levels of sequence similarity with other previously described TNT-degrading enzymes and with their closest potential homologues in databases.
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Affiliation(s)
- Ma Ángeles Cabrera
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile
| | - Sebastián L Márquez
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile
| | - Carolina P Quezada
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile
| | - Manuel I Osorio
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile
| | - Eduardo Castro-Nallar
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile
| | - Fernando D González-Nilo
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile
| | - José M Pérez-Donoso
- Center for Bioinformatics and Integrative Biology (CBIB), Faculty of Life Sciences, Universidad Andrés Bello, Av. República 330, Santiago, Chile.
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Serbent MP, Rebelo AM, Pinheiro A, Giongo A, Tavares LBB. Biological agents for 2,4-dichlorophenoxyacetic acid herbicide degradation. Appl Microbiol Biotechnol 2019; 103:5065-5078. [DOI: 10.1007/s00253-019-09838-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/12/2019] [Accepted: 04/07/2019] [Indexed: 12/22/2022]
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15
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Kitagawa W, Mitsuhashi S, Hata M, Tamura T. Identification of a novel bacteriocin-like protein and structural gene from Rhodococcus erythropolis JCM 2895, using suppression-subtractive hybridization. J Antibiot (Tokyo) 2018; 71:872-879. [PMID: 29980745 DOI: 10.1038/s41429-018-0078-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 06/10/2018] [Accepted: 06/14/2018] [Indexed: 11/09/2022]
Abstract
A novel bacteriocin-like protein and its structural gene (rap) were identified from Rhodococcus erythropolis JCM 2895. The rapA and B genes are located on a 5.4-kb circular plasmid, and were obtained using a modified suppression-subtractive hybridization method. The rapA and B genes were heterologously expressed in Rhodococcus sp. or Escherichia coli, and then characterized. The results indicated that RapA is a small, water-soluble, heat-stable antimicrobial protein, and that RapB is an immunity protein against RapA, estimated to be located on the cell membrane. RapA showed antimicrobial activity particularly against R. erythropolis, and the activity persisted even after SDS-PAGE analysis. For the heterologous expressed RapA protein, N-terminal amino acid sequence was also confirmed. This is the first report of a bacteriocin-like substance obtained from the genus Rhodococcus.
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Affiliation(s)
- Wataru Kitagawa
- National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517, Japan. .,Graduate School of Agriculture, Hokkaido University, Kita 9-Nishi 9, Kita-ku, Sapporo, 060-8589, Japan.
| | - Shinya Mitsuhashi
- Graduate School of Agriculture, Hokkaido University, Kita 9-Nishi 9, Kita-ku, Sapporo, 060-8589, Japan.,Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, 11937 US Highway 271, Tyler, TX, 75708-3154, USA
| | - Miyako Hata
- National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517, Japan
| | - Tomohiro Tamura
- National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517, Japan
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Nielsen TK, Rasmussen M, Demanèche S, Cecillon S, Vogel TM, Hansen LH. Evolution of Sphingomonad Gene Clusters Related to Pesticide Catabolism Revealed by Genome Sequence and Mobilomics of Sphingobium herbicidovorans MH. Genome Biol Evol 2018; 9:2477-2490. [PMID: 28961970 PMCID: PMC5737581 DOI: 10.1093/gbe/evx185] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2017] [Indexed: 12/03/2022] Open
Abstract
Bacterial degraders of chlorophenoxy herbicides have been isolated from various ecosystems, including pristine environments. Among these degraders, the sphingomonads constitute a prominent group that displays versatile xenobiotic-degradation capabilities. Four separate sequencing strategies were required to provide the complete sequence of the complex and plastic genome of the canonical chlorophenoxy herbicide-degrading Sphingobium herbicidovorans MH. The genome has an intricate organization of the chlorophenoxy-herbicide catabolic genes sdpA, rdpA, and cadABCD that encode the (R)- and (S)-enantiomer-specific 2,4-dichlorophenoxypropionate dioxygenases and four subunits of a Rieske non-heme iron oxygenase involved in 2-methyl-chlorophenoxyacetic acid degradation, respectively. Several major genomic rearrangements are proposed to help understand the evolution and mobility of these important genes and their genetic context. Single-strain mobilomic sequence analysis uncovered plasmids and insertion sequence-associated circular intermediates in this environmentally important bacterium and enabled the description of evolutionary models for pesticide degradation in strain MH and related organisms. The mobilome presented a complex mosaic of mobile genetic elements including four plasmids and several circular intermediate DNA molecules of insertion-sequence elements and transposons that are central to the evolution of xenobiotics degradation. Furthermore, two individual chromosomally integrated prophages were shown to excise and form free circular DNA molecules. This approach holds great potential for improving the understanding of genome plasticity, evolution, and microbial ecology.
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Affiliation(s)
| | | | - Sandrine Demanèche
- Environmental Microbial Genomics, Laboratoire Ampère (CNRS UMR5005), École Centrale de Lyon, Université de Lyon, Ecully, France
| | - Sébastien Cecillon
- Environmental Microbial Genomics, Laboratoire Ampère (CNRS UMR5005), École Centrale de Lyon, Université de Lyon, Ecully, France
| | - Timothy M Vogel
- Environmental Microbial Genomics, Laboratoire Ampère (CNRS UMR5005), École Centrale de Lyon, Université de Lyon, Ecully, France
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Zharikova NV, Iasakov TR, Zhurenko EI, Korobov VV, Markusheva TV. Bacterial Genes of Non-Heme Iron Oxygenases, Which Have a Rieske-Type Cluster, Catalyzing Initial Stages of Degradation of Chlorophenoxyacetic Acids. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418030171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kijima K, Mita H, Kawakami M, Amada K. Role of CadC and CadD in the 2,4-dichlorophenoxyacetic acid oxygenase system of Sphingomonas agrestis 58-1. J Biosci Bioeng 2018; 125:649-653. [PMID: 29398549 DOI: 10.1016/j.jbiosc.2018.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/05/2017] [Accepted: 01/05/2018] [Indexed: 12/01/2022]
Abstract
In the present study, we confirm that 2,4-dichlorophenoxyacetic acid (2,4-D) oxygenase from Sphingomonas agrestis 58-1 belongs to the family of Rieske non-heme iron aromatic ring-hydroxylating oxygenases, which comprise a core enzyme (oxygenase), ferredoxin, and oxidoreductase. It has previously been shown that cadAB genes are necessary for the conversion of 2,4-D to 2,4-dichlorophenol; however, the respective roles of ferredoxin and oxidoreductase in the 2,4-D oxygenase system from S. agrestis 58-1 remain unknown. Using nucleotide sequence analysis of the plasmid pCADAB1 from Sphingomonas sp. ERG5, which degrades 4-chloro-2-methylphenoxyacetic acid and 2,4-D, Nielsen et al. identified orf95, upstream of cadA, and orf98, downstream of cadB, which were predicted and designated as cadD (oxidoreductase) and cadC (ferredoxin), respectively (Nielsen et al., PLoS One, 8, e83346, 2013). These designations were the result of sequence analysis; therefore, we constructed an expression system of CadABC and CadABCD in Escherichia coli and assayed their enzyme activities. Our findings indicate that CadC is essential for the activity of 2,4-D oxygenase and CadD promotes CadABC activity in recombinant E. coli cells.
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Affiliation(s)
- Kumiko Kijima
- Division of Material Science and Production Engineering, Graduate School of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi, Fukuoka 811-0295, Japan
| | - Hajime Mita
- Department of Life, Environment and Material Science, Faculty of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi, Fukuoka 811-0295, Japan
| | - Mitsuyasu Kawakami
- Department of Life, Environment and Material Science, Faculty of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi, Fukuoka 811-0295, Japan
| | - Kei Amada
- Department of Life, Environment and Material Science, Faculty of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi, Fukuoka 811-0295, Japan.
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Kulkarni AG, Kaliwal BB. Bioremediation of Methomyl by Escherichia coli. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2018. [DOI: 10.1007/978-1-4939-7425-2_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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20
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Huang X, He J, Yan X, Hong Q, Chen K, He Q, Zhang L, Liu X, Chuang S, Li S, Jiang J. Microbial catabolism of chemical herbicides: Microbial resources, metabolic pathways and catabolic genes. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2017; 143:272-297. [PMID: 29183604 DOI: 10.1016/j.pestbp.2016.11.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/21/2016] [Accepted: 11/23/2016] [Indexed: 06/07/2023]
Abstract
Chemical herbicides are widely used to control weeds and are frequently detected as contaminants in the environment. Due to their toxicity, the environmental fate of herbicides is of great concern. Microbial catabolism is considered the major pathway for the dissipation of herbicides in the environment. In recent decades, there have been an increasing number of reports on the catabolism of various herbicides by microorganisms. This review presents an overview of the recent advances in the microbial catabolism of various herbicides, including phenoxyacetic acid, chlorinated benzoic acid, diphenyl ether, tetra-substituted benzene, sulfonamide, imidazolinone, aryloxyphenoxypropionate, phenylurea, dinitroaniline, s-triazine, chloroacetanilide, organophosphorus, thiocarbamate, trazinone, triketone, pyrimidinylthiobenzoate, benzonitrile, isoxazole and bipyridinium herbicides. This review highlights the microbial resources that are capable of catabolizing these herbicides and the mechanisms involved in the catabolism. Furthermore, the application of herbicide-degrading strains to clean up herbicide-contaminated sites and the construction of genetically modified herbicide-resistant crops are discussed.
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Affiliation(s)
- Xing Huang
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Jian He
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Xin Yan
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Qing Hong
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Kai Chen
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Qin He
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Long Zhang
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Xiaowei Liu
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Shaochuang Chuang
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Shunpeng Li
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China
| | - Jiandong Jiang
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, People's Republic of China.
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Escolà Casas M, Nielsen TK, Kot W, Hansen LH, Johansen A, Bester K. Degradation of mecoprop in polluted landfill leachate and waste water in a moving bed biofilm reactor. WATER RESEARCH 2017; 121:213-220. [PMID: 28544990 DOI: 10.1016/j.watres.2017.05.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/30/2017] [Accepted: 05/14/2017] [Indexed: 05/12/2023]
Abstract
Mecoprop is a common pollutant in effluent-, storm- and groundwater as well as in leachates from derelict dumpsites. Thus, bioremediation approaches may be considered. We conducted batch experiments with moving bed biofilm (MBBR)-carriers to understand the degradation of mecoprop. As a model, the carriers were incubated in effluent from a conventional wastewater treatment plant which was spiked to 10, 50 and 100 μg L-1 mecoprop. Co-metabolic processes as well as mineralization were studied. Initial mecoprop concentration and mecoprop degradation impacted the microbial communities. The removal of (S)-mecoprop prevailed over the (R)-mecoprop. This was associated with microbial compositions, in which several operational taxonomic units (OTUs) co-varied positively with (S)-mecoprop removal. The removal-rate constant of (S)-mecoprop was 0.5 d-1 in the 10 μg L-1 set-up but it decreased in the 50 and 100 μg L-1 set-ups. The addition of methanol prolonged the removal of (R)-mecoprop. During mecoprop degradation, 4-chloro-2-methylphenol was formed and degraded. A new metabolite (4-chloro-2-methylphenol sulfate) was identified and quantified.
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Affiliation(s)
- Mònica Escolà Casas
- Department of Environmental Science, Århus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Tue Kjærgaard Nielsen
- Department of Environmental Science, Århus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Witold Kot
- Department of Environmental Science, Århus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Lars Hestbjerg Hansen
- Department of Environmental Science, Århus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Anders Johansen
- Department of Environmental Science, Århus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Kai Bester
- Department of Environmental Science, Århus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
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Wu X, Wang W, Liu J, Pan D, Tu X, Lv P, Wang Y, Cao H, Wang Y, Hua R. Rapid Biodegradation of the Herbicide 2,4-Dichlorophenoxyacetic Acid by Cupriavidus gilardii T-1. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:3711-3720. [PMID: 28434228 DOI: 10.1021/acs.jafc.7b00544] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Phytotoxicity and environmental pollution of residual herbicides have caused much public concern during the past several decades. An indigenous bacterial strain capable of degrading 2,4-dichlorophenoxyacetic acid (2,4-D), designated T-1, was isolated from soybean field soil and identified as Cupriavidus gilardii. Strain T-1 degraded 2,4-D 3.39 times more rapidly than the model strain Cupriavidus necator JMP134. T-1 could also efficiently degrade 2-methyl-4-chlorophenoxyacetic acid (MCPA), MCPA isooctyl ester, and 2-(2,4-dichlorophenoxy)propionic acid (2,4-DP). Suitable conditions for 2,4-D degradation were pH 7.0-9.0, 37-42 °C, and 4.0 mL of inoculums. Degradation of 2,4-D was concentration-dependent. 2,4-D was degraded to 2,4-dichlorophenol (2,4-DCP) by cleavage of the ether bond and then to 3,5-dichlorocatechol (3,5-DCC) via hydroxylation, followed by ortho-cleavage to cis-2-dichlorodiene lactone (CDL). The metabolites 2,4-DCP or 3,5-DCC at 10 mg L-1 were completely degraded within 16 h. Fast degradation of 2,4-D and its analogues highlights the potential for use of C. gilardii T-1 in bioremediation of phenoxyalkanoic acid herbicides.
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Affiliation(s)
- Xiangwei Wu
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Wenbo Wang
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Junwei Liu
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Dandan Pan
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Xiaohui Tu
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Pei Lv
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Yi Wang
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Haiqun Cao
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Yawen Wang
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
| | - Rimao Hua
- College of Resources and Environment, Key Laboratory of Agri-food Safety of Anhui Province, Anhui Agricultural University , Hefei 230036, People's Republic of China
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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: 39] [Impact Index Per Article: 5.6] [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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Effect of Heavy Metals and Inorganic Nutrients Existing as Co-contaminants on Bioremoval of 2,4-Dichlorophenoxyacetic Acid (2,4-D) by Nostoc hatei TISTR 8405. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2017. [DOI: 10.1007/s13369-017-2492-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Chakraborty J, Das S. Molecular perspectives and recent advances in microbial remediation of persistent organic pollutants. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:16883-16903. [PMID: 27234838 DOI: 10.1007/s11356-016-6887-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/11/2016] [Indexed: 06/05/2023]
Abstract
Nutrition and pollution stress stimulate genetic adaptation in microorganisms and assist in evolution of diverse metabolic pathways for their survival on several complex organic compounds. Persistent organic pollutants (POPs) are highly lipophilic in nature and cause adverse effects to the environment and human health by biomagnification through the food chain. Diverse microorganisms, harboring numerous plasmids and catabolic genes, acclimatize to these environmentally unfavorable conditions by gene duplication, mutational drift, hypermutation, and recombination. Genetic aspects of some major POP catabolic genes such as biphenyl dioxygenase (bph), DDT 2,3-dioxygenase, and angular dioxygenase assist in degradation of biphenyl, organochlorine pesticides, and dioxins/furans, respectively. Microbial metagenome constitutes the largest genetic reservoir with miscellaneous enzymatic activities implicated in degradation. To tap the metabolic potential of microorganisms, recent techniques like sequence and function-based screening and substrate-induced gene expression are proficient in tracing out novel catabolic genes from the entire metagenome for utilization in enhanced biodegradation. The major endeavor of today's scientific world is to characterize the exact genetic mechanisms of microbes for bioremediation of these toxic compounds by excavating into the uncultured plethora. This review entails the effect of POPs on the environment and involvement of microbial catabolic genes for their removal with the advanced techniques of bioremediation.
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Affiliation(s)
- Jaya Chakraborty
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
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Hayashi S, Sano T, Suyama K, Itoh K. 2,4-Dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading gene cluster in the soybean root-nodulating bacterium Bradyrhizobium elkanii USDA94. Microbiol Res 2016; 188-189:62-71. [PMID: 27296963 DOI: 10.1016/j.micres.2016.04.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/29/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
Abstract
Herbicides 2,4-dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading Bradyrhizobium strains possess tfdAα and/or cadABC as degrading genes. It has been reported that root-nodulating bacteria belonging to Bradyrhizobium elkanii also have tfdAα and cadA like genes but lack the ability to degrade these herbicides and that the cadA genes in 2,4-D-degrading and non-degrading Bradyrhizobium are phylogenetically different. In this study, we identified cadRABCK in the genome of a type strain of soybean root-nodulating B. elkanii USDA94 and demonstrated that the strain could degrade the herbicides when cadABCK was forcibly expressed. cadABCK-cloned Escherichia coli also showed the degrading ability. Because co-spiked phenoxyacetic acid (PAA) could induce the degradation of 2,4-D in B. elkanii USDA94, the lack of degrading ability in this strain was supposed to be due to the low inducing potential of the herbicides for the degrading gene cluster. On the other hand, tfdAα from B. elkanii USDA94 showed little potential to degrade the herbicides, but it did for 4-chlorophenoxyacetic acid and PAA. The 2,4-D-degrading ability of the cad cluster and the inducing ability of PAA were confirmed by preparing cadA deletion mutant. This is the first study to demonstrate that the cad cluster in the typical root-nodulating bacterium indeed have the potential to degrade the herbicides, suggesting that degrading genes for anthropogenic compounds could be found in ordinary non-degrading bacteria.
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Affiliation(s)
- Shohei Hayashi
- Faculty of Life and Environmental Science, Shimane University 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Tomoki Sano
- Faculty of Life and Environmental Science, Shimane University 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Kousuke Suyama
- Faculty of Life and Environmental Science, Shimane University 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Kazuhito Itoh
- Faculty of Life and Environmental Science, Shimane University 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan.
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Sheet D, Paine TK. Aerobic alcohol oxidation and oxygen atom transfer reactions catalyzed by a nonheme iron(ii)-α-keto acid complex. Chem Sci 2016; 7:5322-5331. [PMID: 30155184 PMCID: PMC6020522 DOI: 10.1039/c6sc01476c] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 04/23/2016] [Indexed: 11/21/2022] Open
Abstract
An iron(ii)-benzoylformate complex of a monoanionic facial tridentate ligand catalyzes the aerobic oxidation of sulfides to sulfoxides, alkenes to epoxides, and alcohols to the corresponding carbonyl compounds.
α-Ketoglutarate-dependent enzymes catalyze many important biological oxidation/oxygenation reactions. Iron(iv)–oxo intermediates have been established as key oxidants in these oxidation reactions. While most reported model iron(ii)–α-keto acid complexes exhibit stoichiometric reactivity, selective oxidation of substrates with dioxygen catalyzed by biomimetic iron(ii)–α-keto acid complexes remains unexplored. In this direction, we have investigated the ability of an iron(ii) complex [(TpPh,Me)FeII(BF)] (1) (TpPh,Me = hydrotris(3-phenyl-5-methylpyrazolyl)borate and BF = monoanionic benzoylformate) to catalyze the aerobic oxidation of organic substrates. An iron–oxo oxidant, intercepted in the reaction of 1 with O2, selectively oxidizes sulfides to sulfoxides, alkenes to epoxides, and alcohols to the corresponding carbonyl compounds. The oxidant from 1 is able to hydroxylate the benzylic carbon of phenylacetic acid to afford mandelic acid with the incorporation of one oxygen atom from O2 into the product. The iron(ii)–benzoylformate complex oxidatively converts phenoxyacetic acids to the corresponding phenols, thereby mimicking the function of iron(ii)–α-ketoglutarate-dependent 2,4-dichlorophenoxyacetate dioxygenase (TfdA). Furthermore, complex 1 exhibits catalytic aerobic oxidation of alcohols and oxygen atom transfer reactions with multiple turnovers.
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Affiliation(s)
- Debobrata Sheet
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , 2A & 2B Raja S. C. Mullick Road, Jadavpur , Kolkata 700032 , India . ; ; Tel: +91-33-2473-4971
| | - Tapan Kanti Paine
- Department of Inorganic Chemistry , Indian Association for the Cultivation of Science , 2A & 2B Raja S. C. Mullick Road, Jadavpur , Kolkata 700032 , India . ; ; Tel: +91-33-2473-4971
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Chang YC, Reddy MV, Umemoto H, Sato Y, Kang MH, Yajima Y, Kikuchi S. Bio-Augmentation of Cupriavidus sp. CY-1 into 2,4-D Contaminated Soil: Microbial Community Analysis by Culture Dependent and Independent Techniques. PLoS One 2015; 10:e0145057. [PMID: 26710231 PMCID: PMC4699198 DOI: 10.1371/journal.pone.0145057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 11/29/2015] [Indexed: 11/21/2022] Open
Abstract
In the present study, a 2,4-dichlorophenoxyacetic acid (2,4-D) degrading bacterial strain CY-1 was isolated from the forest soil. Based on physiological, biochemical and 16S rRNA gene sequence analysis it was identified as Cupriavidus sp. CY-1. Further 2,4-D degradation experiments at different concentrations (200 to 800 mg l-1) were carried out using CY-1. Effect of NaCl and KNO3 on 2,4-D degradation was also evaluated. Degradation of 2,4-D and the metabolites produced during degradation process were analyzed using high pressure liquid chromatography (HPLC) and GC-MS respectively. The amount of chloride ions produced during the 2,4-D degradation were analyzed by Ion chromatography (IC) and it is stoichiometric with 2,4-D dechlorination. Furthermore two different types of soils collected from two different sources were used for 2,4-D degradation studies. The isolated strain CY-1 was bio-augmented into 2,4-D contaminated soils to analyze its degradation ability. Culture independent methods like denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP), and culture dependent methods like colony forming units (CFU) and most probable number (MPN) were used to analyze the survivability of strain CY-1 in contaminated soil. Results of T-RFLP were coincident with the DGGE analysis. From the DGGE, T-RFLP, MPN and HPLC results it was concluded that strain CY-1 effectively degraded 2,4-D without disturbing the ecosystem of soil indigenous microorganisms.
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Affiliation(s)
- Young-Cheol Chang
- Course of Chemical and Biological Engineering, Division of Sustainable and Environmental Engineering, College of Environmental Technology, Muroran Institute of Technology, 27–1 Mizumoto, Muroran, 050–8585, Japan
- * E-mail:
| | - M. Venkateswar Reddy
- Course of Chemical and Biological Engineering, Division of Sustainable and Environmental Engineering, College of Environmental Technology, Muroran Institute of Technology, 27–1 Mizumoto, Muroran, 050–8585, Japan
| | - Honoka Umemoto
- Course of Chemical and Biological Engineering, Division of Sustainable and Environmental Engineering, College of Environmental Technology, Muroran Institute of Technology, 27–1 Mizumoto, Muroran, 050–8585, Japan
| | - Yuki Sato
- Course of Chemical and Biological Engineering, Division of Sustainable and Environmental Engineering, College of Environmental Technology, Muroran Institute of Technology, 27–1 Mizumoto, Muroran, 050–8585, Japan
| | - Mi-Hye Kang
- Seoul Metropolitan Government Research Institute of Public Health and Environment, 202–3 Yangjae-dong, Seocho-gu, Seoul, 137–893, Republic of Korea
| | - Yuka Yajima
- Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto-shi, Kyoto, 606–8501, Japan
| | - Shintaro Kikuchi
- Course of Chemical and Biological Engineering, Division of Sustainable and Environmental Engineering, College of Environmental Technology, Muroran Institute of Technology, 27–1 Mizumoto, Muroran, 050–8585, Japan
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Khan MI, Yang J, Yoo B, Park J. Improved RDX detoxification with starch addition using a novel nitrogen-fixing aerobic microbial consortium from soil contaminated with explosives. JOURNAL OF HAZARDOUS MATERIALS 2015; 287:243-251. [PMID: 25661171 DOI: 10.1016/j.jhazmat.2015.01.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/13/2015] [Accepted: 01/26/2015] [Indexed: 06/04/2023]
Abstract
In this work, we developed and characterized a novel nitrogen-fixing aerobic microbial consortium for the complete detoxification of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Aerobic RDX biodegradation coupled with microbial growth and nitrogen fixation activity were effectively stimulated by the co-addition of starch and RDX under nitrogen limiting conditions. In the starch-stimulated nitrogen-fixing RDX degradative consortium, the RDX degradation activity was correlated with the xplA and nifH gene copy numbers, suggesting the involvement of nitrogen fixing populations in RDX biodegradation. Formate, nitrite, nitrate, and ammonia were detected as aerobic RDX degradation intermediates without the accumulation of any nitroso-derivatives or NDAB (4-nitro-2,4-diazabutanal), indicating nearly complete mineralization. Pyrosequencing targeting the bacterial 16S rRNA genes revealed that the Rhizobium, Rhizobacter and Terrimonas population increased as the RDX degradation activity increased, suggesting their involvement in the degradation process. These findings imply that the nitrogen-fixing aerobic RDX degrading consortium is a valuable microbial resource for improving the detoxification of RDX-contaminated soil or groundwater, especially when combined with rhizoremediation.
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Affiliation(s)
- Muhammad Imran Khan
- School of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea; Department of Agronomy, University of Agriculture, Faisalabad 38040, Pakistan
| | - Jihoon Yang
- School of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
| | - Byungun Yoo
- School of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
| | - Joonhong Park
- School of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
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Bhat SV, Booth SC, McGrath SGK, Dahms TES. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with "Auxin-Like" Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways. PLoS One 2015; 10:e0123813. [PMID: 25919284 PMCID: PMC4412571 DOI: 10.1371/journal.pone.0123813] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/07/2015] [Indexed: 11/18/2022] Open
Abstract
There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv) as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria.
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Affiliation(s)
- Supriya V. Bhat
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 Canada
| | - Sean C. Booth
- Department of Biological Sciences, University of Calgary, 2500 University Dr, NW Calgary, AB, T2N 1N4 Canada
| | - Seamus G. K. McGrath
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 Canada
| | - Tanya E. S. Dahms
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 Canada
- * E-mail:
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Han L, Liu Y, Li C, Zhao D. Cloning, expression, characterization and mutational analysis of the tfdA gene from Cupriavidus campinensis BJ71. World J Microbiol Biotechnol 2015; 31:1021-30. [PMID: 25850533 DOI: 10.1007/s11274-015-1852-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D)/α-ketoglutarate (α-KG) dioxygenase (TfdA) is an Fe(II)-dependent enzyme that catalyzes the first step in degradation of the herbicide 2,4-D. Previous studies focused on the tfdA gene in Ralstonia eutropha JMP134 isolated in Australia. In this study, a new tfdA gene was cloned from Cupriavidus campinensis BJ71, an effective degrading bacteria from China, based on the iCOnsensus-DEgenerate Hybrid Oligonucleotide Primers (iCODEHOPs) protocol, combined with high-efficiency Thermal Asymmetric Interlaced PCR (hiTAIL-PCR). The open reading frame of 861 bp encoded a putative 287 amino acid protein with a theoretical molecular mass of 32.32 kDa. The gene was overexpressed in Escherichia coli BL21 (DE3) and the purified TfdA showed optimal activity at pH 6.75 and 30 °C. This enzyme was more thermostable and it could use 3-hydrocinnamic acid as substrate, with a similar enzyme activity compared with 2,4-D. TfdA and its variants were created as maltose-binding protein (MBP) tagged fusion proteins to examine the roles of putative substrate-binding residues. The MBP-N110A, MBP-V198A and MBP-R207K proteins showed decreased k cat and increased Km, and MBP-R278A was inactive, suggesting these residues may affect 2,4-D binding or catalysis.
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Affiliation(s)
- Lizhen Han
- Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guiyang, 550025, China,
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Coleman NV. Primers: Functional Genes for Aerobic Chlorinated Hydrocarbon-Degrading Microbes. SPRINGER PROTOCOLS HANDBOOKS 2015. [DOI: 10.1007/8623_2015_91] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
Herbicides remain the most effective, efficient and economical way to control weeds; and its market continues to grow even with the plethora of generic products. With the development of herbicide-tolerant crops, use of herbicides is increasing around the world that has resulted in severe contamination of the environment. The strategies are now being developed to clean these substances in an economical and eco-friendly manner. In this review, an attempt has been made to pool all the available literature on the biodegradation of key herbicides, clodinafop propargyl, 2,4-dichlorophenoxyacetic acid, atrazine, metolachlor, diuron, glyphosate, imazapyr, pendimethalin and paraquat under the following objectives: (1) to highlight the general characteristic and mode of action, (2) to enlist toxicity in animals, (3) to pool microorganisms capable of degrading herbicides, (4) to discuss the assessment of herbicides degradation by efficient microbes, (5) to highlight biodegradation pathways, (6) to discuss the molecular basis of degradation, (7) to enlist the products of herbicides under degradation process, (8) to highlight the factors effecting biodegradation of herbicides and (9) to discuss the future aspects of herbicides degradation. This review may be useful in developing safer and economic microbiological methods for cleanup of soil and water contaminated with such compounds.
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Affiliation(s)
- Baljinder Singh
- a Department of Biotechnology , Panjab University , Chandigarh , Punjab , India
| | - Kashmir Singh
- a Department of Biotechnology , Panjab University , Chandigarh , Punjab , India
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Kumar A, Trefault N, Olaniran AO. Microbial degradation of 2,4-dichlorophenoxyacetic acid: Insight into the enzymes and catabolic genes involved, their regulation and biotechnological implications. Crit Rev Microbiol 2014; 42:194-208. [DOI: 10.3109/1040841x.2014.917068] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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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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Nielsen TK, Xu Z, Gözdereliler E, Aamand J, Hansen LH, Sørensen SR. Novel insight into the genetic context of the cadAB genes from a 4-chloro-2-methylphenoxyacetic acid-degrading Sphingomonas. PLoS One 2013; 8:e83346. [PMID: 24391756 PMCID: PMC3877037 DOI: 10.1371/journal.pone.0083346] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 11/01/2013] [Indexed: 11/19/2022] Open
Abstract
The 2-methyl-4-chlorophenoxyacetic (MCPA) acid-degrader Sphingomonas sp. ERG5 has recently been isolated from MCPA-degrading bacterial communities. Using Illumina-sequencing, the 5.7 Mb genome of this isolate was sequenced in this study, revealing the 138 kbp plasmid pCADAB1 harboring the 32.5 kbp composite transposon Tn6228 which contains genes encoding proteins for the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) and MCPA, as well as the regulation of this pathway. Transposon Tn6228 was confirmed by PCR to be situated on the plasmid and also exist in a circular intermediate state - typical of IS3 elements. The canonical tfdAα-gene of group III 2,4-D degraders, encoding the first step in degradation of 2,4-D and related compounds, was not present in the chromosomal contigs. However, the alternative cadAB genes, also providing the initial degradation step, were found in Tn6228, along with the 2,4-D-degradation-associated genes tfdBCDEFKR and cadR. Putative reductase and ferredoxin genes cadCD of Rieske non-heme iron oxygenases were also present in close proximity to cadAB, suggesting that these might have an unknown role in the initial degradation reaction. Parts of the composite transposon contain sequence displaying high similarity to previously analyzed 2,4-D degradation genes, suggesting rapid dissemination and high conservation of the chlorinated-phenoxyacetic acid (PAA)-degradation genotype among the sphingomonads.
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Affiliation(s)
- Tue Kjærgaard Nielsen
- Department of Geochemistry, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
- Section for Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Zhuofei Xu
- Section for Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Erkin Gözdereliler
- Department of Geochemistry, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
| | - Jens Aamand
- Department of Geochemistry, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
| | | | - Sebastian R. Sørensen
- Department of Geochemistry, Geological Survey of Denmark and Greenland, Copenhagen, Denmark
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Zabaloy MC, Gómez MA. Isolation and characterization of indigenous 2,4-D herbicide degrading bacteria from an agricultural soil in proximity of Sauce Grande River, Argentina. ANN MICROBIOL 2013. [DOI: 10.1007/s13213-013-0731-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Liu YJ, Liu SJ, Drake HL, Horn MA. Consumers of 4-chloro-2-methylphenoxyacetic acid from agricultural soil and drilosphere harborcadA,r/sdpA, andtfdA-like gene encoding oxygenases. FEMS Microbiol Ecol 2013; 86:114-29. [DOI: 10.1111/1574-6941.12144] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 03/15/2013] [Accepted: 05/01/2013] [Indexed: 11/30/2022] Open
Affiliation(s)
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources; Institute of Microbiology; Chinese Academy of Sciences; Beijing; China
| | - Harold L. Drake
- Department of Ecological Microbiology; University of Bayreuth; Bayreuth; Germany
| | - Marcus A. Horn
- Department of Ecological Microbiology; University of Bayreuth; Bayreuth; Germany
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Kitagawa W, Ozaki T, Nishioka T, Yasutake Y, Hata M, Nishiyama M, Kuzuyama T, Tamura T. Cloning and Heterologous Expression of the Aurachin RE Biosynthesis Gene Cluster Afford a New Cytochrome P450 for Quinoline N-Hydroxylation. Chembiochem 2013; 14:1085-93. [DOI: 10.1002/cbic.201300167] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Indexed: 11/10/2022]
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Ditterich F, Poll C, Pagel H, Babin D, Smalla K, Horn MA, Streck T, Kandeler E. Succession of bacterial and fungal 4-chloro-2-methylphenoxyacetic acid degraders at the soil-litter interface. FEMS Microbiol Ecol 2013; 86:85-100. [DOI: 10.1111/1574-6941.12131] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 03/20/2013] [Accepted: 04/03/2013] [Indexed: 11/29/2022] Open
Affiliation(s)
- Franziska Ditterich
- Institute of Soil Science and Land Evaluation; Soil Biology Section; University of Hohenheim; Stuttgart; Germany
| | - Christian Poll
- Institute of Soil Science and Land Evaluation; Soil Biology Section; University of Hohenheim; Stuttgart; Germany
| | - Holger Pagel
- Institute of Soil Science and Land Evaluation; Biogeophysics Section; University of Hohenheim; Stuttgart; Germany
| | - Doreen Babin
- Julius Kühn-Institut; Federal Research Centre for Cultivated Plants; Institute for Epidemiology and Pathogen Diagnostics; Braunschweig; Germany
| | - Kornelia Smalla
- Julius Kühn-Institut; Federal Research Centre for Cultivated Plants; Institute for Epidemiology and Pathogen Diagnostics; Braunschweig; Germany
| | - Marcus A. Horn
- Department of Ecological Microbiology; University of Bayreuth; Bayreuth; Germany
| | - Thilo Streck
- Institute of Soil Science and Land Evaluation; Biogeophysics Section; University of Hohenheim; Stuttgart; Germany
| | - Ellen Kandeler
- Institute of Soil Science and Land Evaluation; Soil Biology Section; University of Hohenheim; Stuttgart; Germany
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Badawi N, Johnsen AR, Sørensen J, Aamand J. Centimeter-scale spatial variability in 2-methyl-4-chlorophenoxyacetic Acid mineralization increases with depth in agricultural soil. JOURNAL OF ENVIRONMENTAL QUALITY 2013; 42:683-689. [PMID: 23673934 DOI: 10.2134/jeq2012.0397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mineralization of organic chemicals in soil is typically studied using large homogenized samples, but little is known about the small-scale spatial distribution of mineralization potential. We studied centimeter-scale spatial distribution of 2-methyl-4-chlorophenoxyacetic acid (MCPA) mineralization activity at different depths (8-115 cm) in a Danish agricultural soil profile using a 96-well microplate C-radiorespirometric method for small-volume samples. The heterotrophic microbial population and specific MCPA degraders decreased 10- to 100-fold from the plow layer to a depth of 115 cm. MCPA was mineralized in all samples in the plow layer, but only about 60% in the transition zone immediately below the plow layer showed mineralization; at greater depth even fewer samples showed mineralization. A patchy spatial distribution of mineralization activity was observed from right below the plow layer and in the subsoil, with a few clearly defined active zones surrounded by areas devoid of mineralization activity. Due to the patchy distribution of mineralization activity at the centimeter scale just beneath the plow layer, MCPA and presumably other weakly sorbing pesticides might be at risk of leaching to the groundwater if transported from the plow layer into the subsoil.
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Modeling of phenoxy acid herbicide mineralization and growth of microbial degraders in 15 soils monitored by quantitative real-time PCR of the functional tfdA gene. Appl Environ Microbiol 2012; 78:5305-12. [PMID: 22635998 DOI: 10.1128/aem.00990-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mineralization potentials, rates, and kinetics of the three phenoxy acid (PA) herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA), and 2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP), were investigated and compared in 15 soils collected from five continents. The mineralization patterns were fitted by zero/linear or exponential growth forms of the three-half-order models and by logarithmic (log), first-order, or zero-order kinetic models. Prior and subsequent to the mineralization event, tfdA genes were quantified using real-time PCR to estimate the genetic potential for degrading PA in the soils. In 25 of the 45 mineralization scenarios, ∼60% mineralization was observed within 118 days. Elevated concentrations of tfdA in the range 1 × 10(5) to 5 × 10(7) gene copies g(-1) of soil were observed in soils where mineralization could be described by using growth-linked kinetic models. A clear trend was observed that the mineralization rates of the three PAs occurred in the order 2,4-D > MCPA > MCPP, and a correlation was observed between rapid mineralization and soils exposed to PA previously. Finally, for 2,4-D mineralization, all seven mineralization patterns which were best fitted by the exponential model yielded a higher tfdA gene potential after mineralization had occurred than the three mineralization patterns best fitted by the Lin model.
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Zona R, Solar S, Sehested K. OH-radical induced degradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 4-chloro-2-methylphenoxyacetic acid (MCPA): A pulse radiolysis and gamma-radiolysis study. Radiat Phys Chem Oxf Engl 1993 2012. [DOI: 10.1016/j.radphyschem.2011.09.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ferreira-Guedes S, Mendes B, Leitão AL. Degradation of 2,4-dichlorophenoxyacetic acid by a halotolerant strain of Penicillium chrysogenum: antibiotic production. ENVIRONMENTAL TECHNOLOGY 2012; 33:677-686. [PMID: 22629643 DOI: 10.1080/09593330.2011.588251] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The extensive use of pesticides in agriculture has prompted intensive research on chemical and biological methods in order to protect contamination of water and soil resources. In this paper the degradation of the pesticide 2,4-dichlorophenoxyacetic acid by a Penicillium chrysogenum strain previously isolated from a salt mine was studied in batch cultures. Co-degradation of 2,4-dichlorophenoxyacetic acid with additives such as sugar and intermediates of pesticide metabolism was also investigated. Penicillium chrysogenum in solid medium was able to grow at concentrations up to 1000 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with sucrose. Meanwhile, supplementation of the solid medium with glucose and lactose led to fungal growth at concentrations up to 500 mg/L of herbicide. Batch cultures of 2,4-D at 100 mg/L were developed under aerobic conditions with the addition of glucose, lactose and sucrose, showing sucrose as the best additional carbon source. The 2,4-D removal was quantified by liquid chromatography. The fungus was able to use 2,4-D as the sole carbon and energy source under 0%, 2% and 5.9% NaCl. The greatest 2,4-D degradation efficiency was found using alpha-ketoglutarate and ascorbic acid as co-substrates under 2% NaCl at pH 7. Penicillin production was evaluated in submerged cultures by bioassay, and higher amounts of beta-lactam antibiotic were produced when the herbicide was alone. Taking into account the ability of P. chrysogenum CLONA2 to degrade aromatic compounds, this strain could be an interesting tool for 2,4-D herbicide remediation in saline environments.
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Affiliation(s)
- Sumaya Ferreira-Guedes
- Grupo de Ecologia da Hidrosfera, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, UBiA, Campus de Caparica, 2829-516 Caparica, Portugal
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Batıoğlu-Pazarbaşı M, Baelum J, Johnsen AR, Sørensen SR, Albrechtsen HJ, Aamand J. Centimetre-scale vertical variability of phenoxy acid herbicide mineralization potential in aquifer sediment relates to the abundance of tfdA genes. FEMS Microbiol Ecol 2012; 80:331-41. [DOI: 10.1111/j.1574-6941.2012.01300.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Jacob Baelum
- Department of Geochemistry; Geological Survey of Denmark and Greenland (GEUS); Copenhagen K; Denmark
| | - Anders R. Johnsen
- Department of Geochemistry; Geological Survey of Denmark and Greenland (GEUS); Copenhagen K; Denmark
| | - Sebastian R. Sørensen
- Department of Geochemistry; Geological Survey of Denmark and Greenland (GEUS); Copenhagen K; Denmark
| | - Hans-Jørgen Albrechtsen
- DTU Environment; Department of Environmental Engineering; Technical University of Denmark; Kgs. Lyngby; Denmark
| | - Jens Aamand
- Department of Geochemistry; Geological Survey of Denmark and Greenland (GEUS); Copenhagen K; Denmark
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Paulin MM, Nicolaisen MH, Sørensen J. (R,S)-dichlorprop herbicide in agricultural soil induces proliferation and expression of multiple dioxygenase-encoding genes in the indigenous microbial community. Environ Microbiol 2011; 13:1513-23. [DOI: 10.1111/j.1462-2920.2011.02456.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Lu Y, Yu Y, Zhou R, Sun W, Dai C, Wan P, Zhang L, Hao D, Ren H. Cloning and characterisation of a novel 2,4-dichlorophenol hydroxylase from a metagenomic library derived from polychlorinated biphenyl-contaminated soil. Biotechnol Lett 2011; 33:1159-67. [PMID: 21293902 DOI: 10.1007/s10529-011-0549-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 01/21/2011] [Indexed: 11/28/2022]
Abstract
A novel 2,4-dichlorophenol hydroxylase (TfdB, EC 1.14.13.20) gene, designated as tfdB-JLU, was identified from a metagenome constructed from polychlorinated biphenyl-contaminated soil by functional screening and heterologously expressed in Escherichia coli. The deduced amino acid sequence of tfdB-JLU exhibited less than 48% homology with other known TfdBs. The enzyme exhibited a wider substrate spectrum than the previously reported TfdBs and higher relative activity towards ortho-substituted dichlorophenols, 2-chlorophenol, and 3-chlorophenol than towards 2,4-dichlorophenol, the preferred substrate of other known TfdBs. The enzyme had a K ( m ) of 5 μM for 2,4-dichlorophenol and 6 μM for NADPH. The optimal temperature and pH of the enzyme were 25°C and 7.5, respectively. Activity of the purified TfdB-JLU was slightly enhanced by Ca(2+), Mn(2+), Co(2+), and Fe(2+), and completely inhibited by Cu(2+), Hg(2+), and Zn(2+). This study is the first report to identify a novel TfdB from a metagenome.
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Affiliation(s)
- Yang Lu
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun, 130012, People's Republic of China
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Liu YJ, Liu SJ, Drake HL, Horn MA. Alphaproteobacteria dominate active 2-methyl-4-chlorophenoxyacetic acid herbicide degraders in agricultural soil and drilosphere. Environ Microbiol 2011; 13:991-1009. [DOI: 10.1111/j.1462-2920.2010.02405.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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The earthworm Aporrectodea caliginosa stimulates abundance and activity of phenoxyalkanoic acid herbicide degraders. ISME JOURNAL 2010; 5:473-85. [PMID: 20740027 DOI: 10.1038/ismej.2010.140] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a widely used phenoxyalkanoic acid (PAA) herbicide. Earthworms represent the dominant macrofauna and enhance microbial activities in many soils. Thus, the effect of the model earthworm Aporrectodea caliginosa (Oligochaeta, Lumbricidae) on microbial MCPA degradation was assessed in soil columns with agricultural soil. MCPA degradation was quicker in soil with earthworms than without earthworms. Quantitative PCR was inhibition-corrected per nucleic acid extract and indicated that copy numbers of tfdA-like and cadA genes (both encoding oxygenases initiating aerobic PAA degradation) in soil with earthworms were up to three and four times higher than without earthworms, respectively. tfdA-like and 16S rRNA gene transcript copy numbers in soil with earthworms were two and six times higher than without earthworms, respectively. Most probable numbers (MPNs) of MCPA degraders approximated 4 × 10(5) g(dw)(-1) in soil before incubation and in soil treated without earthworms, whereas MPNs of earthworm-treated soils were approximately 150 × higher. The aerobic capacity of soil to degrade MCPA was higher in earthworm-treated soils than in earthworm-untreated soils. Burrow walls and 0-5 cm depth bulk soil displayed higher capacities to degrade MCPA than did soil from 5-10 cm depth bulk soil, expression of tfdA-like genes in burrow walls was five times higher than in bulk soil and MCPA degraders were abundant in burrow walls (MPNs of 5 × 10(7) g(dw)(-1)). The collective data indicate that earthworms stimulate abundance and activity of MCPA degraders endogenous to soil by their burrowing activities and might thus be advantageous for enhancing PAA degradation in soil.
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Lillis L, Doyle E, Clipson N. Comparison of DNA- and RNA-based bacterial community structures in soil exposed to 2,4-dichlorophenol. J Appl Microbiol 2010; 107:1883-93. [PMID: 20426769 DOI: 10.1111/j.1365-2672.2009.04369.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS To examine the effect of the pollutant 2,4-dichlorophenol on DNA- and RNA-based bacterial communities in soil. METHODS AND RESULTS Soil was exposed to 100 mg kg(-1) of 2,4-dichlorophenol (2,4-DCP), and degradation was monitored over 35 days. DNA and RNA were coextracted, and terminal restriction fragment length polymorphism (T-RFLP) was used to report changes in bacterial communities in response to the presence of the chlorophenol. The phylogenetic composition of the soil during degradation was determined by creating a clone library of amplified 16S rRNA sequences from both DNA and reverse-transcribed RNA from exposed soil. Resulting clones were sequenced, and putative identities were assigned. CONCLUSIONS A significant difference between active (RNA-based) and total (DNA-based) bacterial community structure was observed for both T-RFLP and phylogenetic analyses in response to 2,4-DCP, with more pronounced changes seen in RNA-based communities. Phylogenetic analysis indicated the dominance of Proteobacteria in both profiles. SIGNIFICANCE AND IMPACT OF THE STUDY This study describes the response of soil bacterial communities to the addition of the xenobiotic compound 2,4-DCP, and highlights the importance of including RNA-based 16S rRNA analysis to complement any molecular study in a perturbed soil.
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Affiliation(s)
- L Lillis
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin, Ireland.
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