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Zhang ST, Li T, Deng SK, Spain JC, Zhou NY. A cytochrome P450 system initiates 4-nitroanisole degradation in Rhodococcus sp. strain JS3073. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131886. [PMID: 37348368 DOI: 10.1016/j.jhazmat.2023.131886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/24/2023]
Abstract
Nitroanisoles are used widely as synthetic intermediates and explosives. Although bacteria have been reported to degrade 4-nitroanisole (4NA) under aerobic conditions, the key enzymes and the catalytic mechanism have remained elusive. Rhodococcus sp. strain JS3073 was isolated for its ability to grow on 4NA as the sole carbon and energy source. In this study, whole cell biotransformation experiments indicated that 4NA degradation is initiated by O-demethylation to form 4-nitrophenol (PNP), which undergoes subsequent degradation by a previously established pathway involving formation of 1,2,4-benzenetriol and release of nitrite. Based on comparative transcriptomics and heterologous expression, a novel three-component cytochrome P450 system encoded by pnaABC initiates the O-demethylation of 4NA to yield formaldehyde and PNP. The pnaABC genes encode a phthalate dioxygenase type reductase (PnaA), a cytochrome P450 monooxygenase (PnaB), and an EthD family protein (PnaC) with putative function similar to ferredoxins. This unusual P450 system also has a broad substrate specificity for nitroanisole derivatives. Sequence analysis of PnaAB revealed high identity with multiple self-sufficient P450s of the CYP116B subfamily. The findings revealed the molecular basis of the catabolic pathway for 4NA initiated by an unusual O-demethylase PnaABC and extends the understanding of the diversity among P450s and their electron transport chains.
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Affiliation(s)
- Shu-Ting Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tao Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shi-Kai Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jim C Spain
- Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Pensacola, FL 32514-5751, USA
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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2
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Aldas-Vargas A, Poursat BAJ, Sutton NB. Potential and limitations for monitoring of pesticide biodegradation at trace concentrations in water and soil. World J Microbiol Biotechnol 2022; 38:240. [PMID: 36261779 PMCID: PMC9581840 DOI: 10.1007/s11274-022-03426-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022]
Abstract
Pesticides application on agricultural fields results in pesticides being released into the environment, reaching soil, surface water and groundwater. Pesticides fate and transformation in the environment depend on environmental conditions as well as physical, chemical and biological degradation processes. Monitoring pesticides biodegradation in the environment is challenging, considering that traditional indicators, such as changes in pesticides concentration or identification of pesticide metabolites, are not suitable for many pesticides in anaerobic environments. Furthermore, those indicators cannot distinguish between biotic and abiotic pesticide degradation processes. For that reason, the use of molecular tools is important to monitor pesticide biodegradation-related genes or microorganisms in the environment. The development of targeted molecular (e.g., qPCR) tools, although laborious, allowed biodegradation monitoring by targeting the presence and expression of known catabolic genes of popular pesticides. Explorative molecular tools (i.e., metagenomics & metatranscriptomics), while requiring extensive data analysis, proved to have potential for screening the biodegradation potential and activity of more than one compound at the time. The application of molecular tools developed in laboratory and validated under controlled environments, face challenges when applied in the field due to the heterogeneity in pesticides distribution as well as natural environmental differences. However, for monitoring pesticides biodegradation in the field, the use of molecular tools combined with metadata is an important tool for understanding fate and transformation of the different pesticides present in the environment.
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Affiliation(s)
- Andrea Aldas-Vargas
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 EV, Wageningen, The Netherlands
| | - Baptiste A J Poursat
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 EV, Wageningen, The Netherlands
| | - Nora B Sutton
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 EV, Wageningen, The Netherlands.
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3
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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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4
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Zhou J, Wang D, Ju F, Hu W, Liang J, Bai Y, Liu H, Qu J. Profiling microbial removal of micropollutants in sand filters: Biotransformation pathways and associated bacteria. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127167. [PMID: 34536843 DOI: 10.1016/j.jhazmat.2021.127167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/13/2021] [Accepted: 09/05/2021] [Indexed: 06/13/2023]
Abstract
Although there is growing evidence that micropollutants can be microbially converted in rapid sand filters of drinking water treatment plants (DWTPs), little is known about the biotransformation pathways and associated microbial strains in this process. Here, we constructed sand filter columns filled with manganese or quartz sand obtained from full-scale DWTPs to explore the biotransformation of eight micropollutants. Under seven different empty bed contact times (EBCTs), the column experiments showed that caffeine and atenolol were easily removed (up to 92.1% and 97.6%, respectively) with adsorption and microbial biotransformation of the filters. In contrast, the removal of other six micropollutants (i.e., naproxen, carbamazepine, atrazine, trimethoprim, sulfamethoxazole, and sulfadiazine) in the filters were less than 27.1% at shorter EBCTs, but significantly increased at EBCT = 4 h, indicating the dominant role of microbial biotransformation in these micropollutants removal. Integrated analysis of metagenomic reads and transformation products of micropollutants showed a shift in caffeine oxidation and demethylation pathways at different EBCTs, simultaneous occurrence of atrazine hydrolysis and oxidation pathways, and sulfadiazine and sulfamethoxazole oxidation in the filters. Furthermore, using genome-centric analysis, we observed previously unidentified degrading strains, e.g., Piscinibacter, Hydrogenophaga, and Rubrivivax for caffeine transformation, and Methylophilus and Methyloversatilis for atenolol transformation.
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Affiliation(s)
- Jie Zhou
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Donglin Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China; Institute of Advanced Technology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, China
| | - Wanchao Hu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jinsong Liang
- School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Yaohui Bai
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Huijuan Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Mishra S, Pang S, Zhang W, Lin Z, Bhatt P, Chen S. Insights into the microbial degradation and biochemical mechanisms of carbamates. CHEMOSPHERE 2021; 279:130500. [PMID: 33892453 DOI: 10.1016/j.chemosphere.2021.130500] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 03/01/2021] [Accepted: 04/04/2021] [Indexed: 06/12/2023]
Abstract
Carbamate compounds are commonly applied in agricultural sectors as alternative options to the recalcitrant organochlorine pesticides due to their easier breakdown and less persistent nature. However, the large-scale use of carbamates also leads to toxic environmental residues, causing severe toxicity in various living systems. The toxic effects of carbamates are due to their inhibitor activity against the acetylchlolinesterase enzyme. This enzyme is crucial for neurotransmission signaling in living beings. Hence, from the environmental point of view, the elimination of carbamates is a worldwide concern and priority. Microbial technology can be deliberated as a potential tool that can work efficiently and as an ecofriendly option for the dissipation of carbamate insecticides from contaminated environments by improving biodegradation processes via metabolic activities of microorganisms. A variety of bacterial and fungal species have been isolated and characterized and are capable of degrading a broad range of carbamates in soil and water environments. In addition, microbial carbamate hydrolase genes (mcd, cehA, cahA, cfdJ, and mcbA) were strongly implicated in the evolution of new metabolic functions and carbamate hydrolase enzymes. However, the accurate localization and appropriate functions of carbamate hydrolase enzymes/genes are very limited. To explore the information on the degradation routes of carbamates and promote the application of biodegradation, a study of molecular techniques is required to unlock insights regarding the degradation specific genes and enzymes. Hence, this review discusses the deep understanding of carbamate degradation mechanisms with microbial strains, metabolic pathways, molecular mechanisms, and their genetic basis in degradation.
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Affiliation(s)
- Sandhya Mishra
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Shimei Pang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Wenping Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Ziqiu Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Pankaj Bhatt
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
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6
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Liang Y, Yu H. Genetic toolkits for engineering Rhodococcus species with versatile applications. Biotechnol Adv 2021; 49:107748. [PMID: 33823269 DOI: 10.1016/j.biotechadv.2021.107748] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 02/09/2023]
Abstract
Rhodococcus spp. are a group of non-model gram-positive bacteria with diverse catabolic activities and strong adaptive capabilities, which enable their wide application in whole-cell biocatalysis, environmental bioremediation, and lignocellulosic biomass conversion. Compared with model microorganisms, the engineering of Rhodococcus is challenging because of the lack of universal molecular tools, high genome GC content (61% ~ 71%), and low transformation and recombination efficiencies. Nevertheless, because of the high interest in Rhodococcus species for bioproduction, various genetic elements and engineering tools have been recently developed for Rhodococcus spp., including R. opacus, R. jostii, R. ruber, and R. erythropolis, leading to the expansion of the genetic toolkits for Rhodococcus engineering. In this article, we provide a comprehensive review of the important developed genetic elements for Rhodococcus, including shuttle vectors, promoters, antibiotic markers, ribosome binding sites, and reporter genes. In addition, we also summarize gene transfer techniques and strategies to improve transformation efficiency, as well as random and precise genome editing tools available for Rhodococcus, including transposition, homologous recombination, recombineering, and CRISPR/Cas9. We conclude by discussing future trends in Rhodococcus engineering. We expect that more synthetic and systems biology tools (such as multiplex genome editing, dynamic regulation, and genome-scale metabolic models) will be adapted and optimized for Rhodococcus.
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Affiliation(s)
- Youxiang Liang
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Industrial Biocatalysis (Tsinghua University), the Ministry of Education, Beijing 100084, China
| | - Huimin Yu
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Industrial Biocatalysis (Tsinghua University), the Ministry of Education, Beijing 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China.
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7
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Jiang B, Jin N, Xing Y, Su Y, Zhang D. Unraveling uncultivable pesticide degraders via stable isotope probing (SIP). Crit Rev Biotechnol 2018; 38:1025-1048. [DOI: 10.1080/07388551.2018.1427697] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Bo Jiang
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, PR China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, PR China
| | - Naifu Jin
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science & Technology Beijing, Beijing, PR China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science & Technology Beijing, Beijing, PR China
| | - Yuping Su
- Environmental Science and Engineering College, Fujian Normal University, Fuzhou, PR China
| | - Dayi Zhang
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
- Environmental Science and Engineering College, Fujian Normal University, Fuzhou, PR China
- School of Environment, Tsinghua University, Beijing, PR China
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8
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Háhn J, Szoboszlay S, Tóth G, Kriszt B. Assessment of bacterial biodetoxification of herbicide atrazine using Aliivibrio fischeri cytotoxicity assay with prolonged contact time. ECOTOXICOLOGY (LONDON, ENGLAND) 2017; 26:648-657. [PMID: 28466204 DOI: 10.1007/s10646-017-1797-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/22/2017] [Indexed: 06/07/2023]
Abstract
In our study, we determined and compared the atrazine-biodetoxification ability of 41 bacterial strains and 21 consortia created of those with over 50% degradation rate in pure cultures. Biodegradation capacity was measured with GC-MS. Detoxification was assessed based on the cytotoxic effect of end-products to Aliivibrio fischeri in chronic bioluminescence inhibition assay with 25 h contact time. Chronic A. fischeri assay adapted to a microplate, which is suitable for examine numerous residues simultaneously, also appeared to be significantly more sensitive to atrazine compared to the standard acute (30 min) test. Due to its sensitivity, the chronic assay could be a valuable tool to provide a more comprehensive view of the ecological risks of atrazine and other chemicals. Thirteen strains were able to degrade more than 50% of 50 ppm atrazine. Four of these belong to Rhodococcus aetherivorans, R. qingshengii, Serratia fonticola and Olivibacter oleidegradans which species' atrazine degrading ability has never been reported before. Four consortia degrading ability was more effective than that of the creating individual strains; moreover, their residues did not show cytotoxic effects to A. fischeri. However, in several cases, the degradation products of sole strains and consortia resulted in significant bioluminescence inhibition. Thus high biodegradation (>90%) does not certainly mean the reduction or cessation of toxicity highlighting the importance of the evaluation of biological effects of degradation residues to improve the efficiency and abate the ecological risks of bioremediation techniques.
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Affiliation(s)
- Judit Háhn
- Szent István University, Regional University Center of Excellence, 1 Páter Károly Street, Gödöllő, 2100, Hungary
| | - Sándor Szoboszlay
- Department of Environmental Safety and Ecotoxicology, Szent István University, 1 Páter Károly Street, Gödöllő, 2100, Hungary.
| | - Gergő Tóth
- Department of Environmental Safety and Ecotoxicology, Szent István University, 1 Páter Károly Street, Gödöllő, 2100, Hungary
| | - Balázs Kriszt
- Department of Environmental Safety and Ecotoxicology, Szent István University, 1 Páter Károly Street, Gödöllő, 2100, Hungary
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9
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Yale RL, Sapp M, Sinclair CJ, Moir JWB. Microbial changes linked to the accelerated degradation of the herbicide atrazine in a range of temperate soils. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:7359-7374. [PMID: 28108915 PMCID: PMC5383679 DOI: 10.1007/s11356-017-8377-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 01/03/2017] [Indexed: 05/11/2023]
Abstract
Accelerated degradation is the increased breakdown of a pesticide upon its repeated application, which has consequences for the environmental fate of pesticides. The herbicide atrazine was repeatedly applied to soils previously untreated with s-triazines for >5 years. A single application of atrazine, at an agriculturally relevant concentration, was sufficient to induce its rapid dissipation. Soils, with a range of physico-chemical properties and agricultural histories, showed similar degradation kinetics, with the half-life of atrazine decreasing from an average of 25 days after the first application to <2 days after the second. A mathematical model was developed to fit the atrazine-degrading kinetics, which incorporated the exponential growth of atrazine-degrading organisms. Despite the similar rates of degradation, the repertoire of atrazine-degrading genes varied between soils. Only a small portion of the bacterial community had the capacity for atrazine degradation. Overall, the microbial community was not significantly affected by atrazine treatment. One soil, characterised by low pH, did not exhibit accelerated degradation, and atrazine-degrading genes were not detected. Neutralisation of this soil restored accelerated degradation and the atrazine-degrading genes became detectable. This illustrates the potential for accelerated degradation to manifest when conditions become favourable. Additionally, the occurrence of accelerated degradation under agriculturally relevant concentrations supports the consideration of the phenomena in environmental risk assessments.
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Affiliation(s)
- R. L. Yale
- CRD, Mallard House, 3 Peasholme Green, York, YO1 7PX UK
- Department of Biology, University of York, Heslington, York, YO10 5DD UK
- FERA Science Ltd., Sand Hutton, York, YO41 1LZ UK
| | - M. Sapp
- FERA Science Ltd., Sand Hutton, York, YO41 1LZ UK
- Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, NRW Germany
| | | | - J. W. B. Moir
- Department of Biology, University of York, Heslington, York, YO10 5DD UK
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10
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Bui SH, McLean KJ, Cheesman MR, Bradley JM, Rigby SEJ, Levy CW, Leys D, Munro AW. Unusual spectroscopic and ligand binding properties of the cytochrome P450-flavodoxin fusion enzyme XplA. J Biol Chem 2012; 287:19699-714. [PMID: 22500029 PMCID: PMC3366004 DOI: 10.1074/jbc.m111.319202] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 04/05/2012] [Indexed: 11/06/2022] Open
Abstract
The Rhodococcus rhodochrous strain 11Y XplA enzyme is an unusual cytochrome P450-flavodoxin fusion enzyme that catalyzes reductive denitration of the explosive hexahydro-1,3,5-trinitro-1,3,5-triazene (RDX). We show by light scattering that XplA is a monomeric enzyme. XplA has high affinity for imidazole (K(d) = 1.6 μM), explaining previous reports of a red-shifted XplA Soret band in pure enzyme. The true Soret maximum of XplA is at 417 nm. Similarly, unusually weak XplA flavodoxin FMN binding (K(d) = 1.09 μM) necessitates its purification in the presence of the cofactor to produce hallmark flavin contributions absent in previously reported spectra. Structural and ligand-binding data reveal a constricted active site able to accommodate RDX and small inhibitory ligands (e.g. 4-phenylimidazole and morpholine) while discriminating against larger azole drugs. The crystal structure also identifies a high affinity imidazole binding site, consistent with its low K(d), and shows active site penetration by PEG, perhaps indicative of an evolutionary lipid-metabolizing function for XplA. EPR studies indicate heterogeneity in binding mode for RDX and other ligands. The substrate analog trinitrobenzene does not induce a substrate-like type I optical shift but creates a unique low spin EPR spectrum due to influence on structure around the distal water heme ligand. The substrate-free heme iron potential (-268 mV versus NHE) is positive for a low spin P450, and the elevated potential of the FMN semiquinone/hydroquinone couple (-172 mV) is also an adaptation that may reflect (along with the absence of a key Thr/Ser residue conserved in oxygen-activating P450s) the evolution of XplA as a specialized RDX reductase catalyst.
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Affiliation(s)
- Soi H. Bui
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom and
| | - Kirsty J. McLean
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom and
| | - Myles R. Cheesman
- the School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Justin M. Bradley
- the School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Stephen E. J. Rigby
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom and
| | - Colin W. Levy
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom and
| | - David Leys
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom and
| | - Andrew W. Munro
- From the Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom and
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11
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De Mot R, De Schrijver A, Schoofs G, Parret AHA. The thiocarbamate-inducible Rhodococcus enzyme ThcF as a member of the family of alpha/beta hydrolases with haloperoxidative side activity. FEMS Microbiol Lett 2003; 224:197-203. [PMID: 12892883 DOI: 10.1016/s0378-1097(03)00452-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Purified thiocarbamate-inducible ThcF of Rhodococcus erythropolis NI86/21, overexpressed in Escherichia coli, displayed several characteristics of the HASH family of enzymes that groups prokaryotic proteins of the alpha/beta hydrolase superfamily possessing serine-dependent hydrolase and/or haloperoxidase activity. Kinetic analysis of bromination and ester hydrolysis revealed a low affinity of ThcF for model substrates. Sulfoxidation of thiocarbamates was demonstrated but probably represents a side activity due to peroxoacid generation by the enzyme. The thcF-linked thcG gene, encoding a LAL-type regulator, triggers expression of thcF in Rhodococcus. The tandem gene organization thcG-thcF is conserved in the thiocarbamate-degrading strain Rhodococcus sp. B30. It is proposed that HASH enzymes may be involved in the metabolism of plant-derived compounds.
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Affiliation(s)
- René De Mot
- Department of Applied Plant Sciences, Catholic University of Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
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12
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Rousseaux S, Hartmann A, Soulas G. Isolation and characterisation of new Gram-negative and Gram-positive atrazine degrading bacteria from different French soils. FEMS Microbiol Ecol 2001; 36:211-222. [PMID: 11451526 DOI: 10.1111/j.1574-6941.2001.tb00842.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The capacity of 12 soils to degrade atrazine was studied in laboratory incubations using radiolabelled atrazine. Eight soils showed enhanced degradation of this compound. Twenty-five bacterial strains able to degrade atrazine were isolated by an enrichment method from 10 of these soils. These soils were chosen for their wide range of physico-chemical characteristics. Their history of treatment with atrazine was also variable. The genetic diversity of atrazine degraders was determined by amplified ribosomal restriction analysis (ARDRA) of the 16S rDNA gene with three restriction endonucleases. The 25 bacterial strains were grouped into five ARDRA types. By sequencing and aligning the 16S rDNA genes, the isolates were shown to belong to the Gram-negative species Chelatobacter heintzii, Aminobacter aminovorans, Stenotrophomonas maltophilia and to the Gram-positive genus Arthrobacter crystallopoietes. These species were not described previously as being capable of atrazine degradation. Most Gram-negative bacteria could mineralise (14)C ring labelled atrazine and carried the atzA, atzB, atzC and trzD genes. Gram-positive strains could convert atrazine to cyanuric acid and carried only the atzB and atzC genes. In this study, we describe the atrazine degradation capacities and corresponding genes in bacterial species that were not known as atrazine degraders. We report for the first time the occurrence of the trzD gene in these atrazine-mineralising bacteria and we demonstrate the potential use of colony hybridisation to isolate bacteria involved in atrazine degradation.
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Affiliation(s)
- S Rousseaux
- Laboratoire de Microbiologie des Sols, Centre de Microbiologie du Sol et de l'Environnement, INRA, 17 rue Sully, P.O. Box 86510, 21065 Cedex, Dijon, France
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Kalogeraki VS, Winans SC. Wound-released chemical signals may elicit multiple responses from an Agrobacterium tumefaciens strain containing an octopine-type Ti plasmid. J Bacteriol 1998; 180:5660-7. [PMID: 9791116 PMCID: PMC107625 DOI: 10.1128/jb.180.21.5660-5667.1998] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/1998] [Accepted: 08/25/1998] [Indexed: 11/20/2022] Open
Abstract
The vir regions of octopine-type and nopaline-type Ti plasmids direct the transfer of oncogenic T-DNA from Agrobacterium tumefaciens to the nuclei of host plant cells. Previous studies indicate that at least two genetic loci at the left ends of these two vir regions are sufficiently conserved to form heteroduplexes visible in the electron microscope. To initiate an investigation of these genetic loci, we determined the DNA sequences of these regions of both Ti plasmids and identified both conserved loci. One of these is the 2.5-kb virH locus, which was previously identified on the octopine-type Ti plasmid but thought to be absent from the nopaline-type Ti plasmid. The virH operon contains two genes that resemble P-450-type monooxygenases. The other locus encodes a 0.5-kb gene designated virK. In addition, we identified other potential genes in this region that are not conserved between these two plasmids. To determine (i) whether these genes are members of the vir regulon and, (ii) whether they are required for tumorigenesis, we used a genetic technique to disrupt each gene and simultaneously fuse its promoter to lacZ. Expression of these genes was also measured by nuclease S1 protection assays. virK and two nonconserved genes, designated virL and virM, were strongly induced by the vir gene inducer acetosyringone. Disruptions of virH, virK, virL, or virM did not affect tumorigenesis of Kalanchöe diagramontiana leaves or carrot disks, suggesting that they may play an entirely different role during pathogenesis.
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Affiliation(s)
- V S Kalogeraki
- Section of Microbiology, Cornell University, Ithaca, New York 14853, USA
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Zheng H, Tkachuk-Saad O, Prescott JF. Development of a Rhodococcus equi-Escherichia coli plasmid shuttle vector. Plasmid 1998; 38:180-7. [PMID: 9435020 DOI: 10.1006/plas.1997.1311] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Isolates of Rhodococcus equi from pneumonic foals possess an 85- or 90-kb virulence-associated plasmid. A prominent, thermoregulated surface antigen, VapA, encoded by these plasmids is thought to be important in virulence. A 135-kb fragment containing the origin of replication of R. equi strain 103 virulence-associated plasmid (pOTS) was identified, sequenced, and its location identified. A simple R. equi-Escherichia coli shuttle plasmid (pRE-1) derived from the E. coli plasmid pACYC177 and the pOTS ori was developed. The plasmid transformed readily and was stable in either host and expressed kanamycin resistance but not beta-lactamase in R. equi. An improved 5.9-kb vector, pRE-7, was developed from pRE-1 and pBluescript. Subcloning of vapA into the multiple cloning site of the beta-galactosidase gene of pRE-7 resulted in weak expression of the gene both in E. coli and R. equi. The shuttle vector may be useful in examining regulation of virulence gene expression in R. equi.
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Affiliation(s)
- H Zheng
- Department of Pathobiology, University of Guelph, Ontario, Canada
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Sadowsky MJ, Tong Z, de Souza M, Wackett LP. AtzC is a new member of the amidohydrolase protein superfamily and is homologous to other atrazine-metabolizing enzymes. J Bacteriol 1998; 180:152-8. [PMID: 9422605 PMCID: PMC106861 DOI: 10.1128/jb.180.1.152-158.1998] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Pseudomonas sp. strain ADP metabolizes atrazine to cyanuric acid via three plasmid-encoded enzymes, AtzA, AtzB, and AtzC. The first enzyme, AtzA, catalyzes the hydrolytic dechlorination of atrazine, yielding hydroxyatrazine. The second enzyme, AtzB, catalyzes hydroxyatrazine deamidation, yielding N-isopropylammelide. In this study, the third gene in the atrazine catabolic pathway, atzC, was cloned from a Pseudomonas sp. strain ADP cosmid library as a 25-kb EcoRI DNA fragment in Escherichia coli. The atzC gene was further delimited by functional analysis following transposon Tn5 mutagenesis and subcloned as a 2.0-kb EcoRI-AvaI fragment. An E. coli strain containing this DNA fragment expressed N-isopropylammelide isopropylamino hydrolase activity, metabolizing N-isopropylammelide stoichiometrically to cyanuric acid and N-isopropylamine. The 2.0-kb DNA fragment was sequenced and found to contain a single open reading frame of 1,209 nucleotides, encoding a protein of 403 amino acids. AtzC showed modest sequence identity of 29 and 25%, respectively, to cytosine deaminase and dihydroorotase, both members of an amidohydrolase protein superfamily. The sequence of AtzC was compared to that of E. coli cytosine deaminase in the regions containing the five ligands to the catalytically important metal for the protein. Pairwise comparison of the 35 amino acids showed 61% sequence identity and 85% sequence similarity. AtzC is thus assigned to the amidohydrolase protein family that includes cytosine deaminase, urease, adenine deaminase, and phosphotriester hydrolase. Similar sequence comparisons of the most highly conserved regions indicated that the AtzA and AtzB proteins also belong to the same amidohydrolase family. Overall, the data suggest that AtzA, AtzB, and AtzC diverged from a common ancestor and, by random events, have been reconstituted onto an atrazine catabolic plasmid.
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Affiliation(s)
- M J Sadowsky
- Department of Microbiology, Institute for Advanced Studies in Biological Process Technology, University of Minnesota, St. Paul 55108, USA.
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De Schrijver A, Nagy I, Schoofs G, Proost P, Vanderleyden J, van Pée KH, De Mot R. Thiocarbamate herbicide-inducible nonheme haloperoxidase of Rhodococcus erythropolis NI86/21. Appl Environ Microbiol 1997; 63:1911-6. [PMID: 9143122 PMCID: PMC168482 DOI: 10.1128/aem.63.5.1911-1916.1997] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
During biodegradation of thiocarbamate herbicides by Rhodococcus erythropolis NI86/21, a protein with an M(r) of 30,000 is induced (I. Nagy, G. Schoofs, F. Compernolle, P. Proost, J. Vanderleyden, and R.De Mot, J. Bacteriol. 177:676-687, 1995). Based on N-terminal sequence data for the protein purified by two-dimensional electrophoresis, the corresponding structural gene, thcF, was cloned and sequenced. The deduced protein sequence of ThcF is homologous to those of nonheme haloperoxidases. A particularly high level of sequence identity (72.6%) was observed for the chloroperoxidase from Pseudomonas pyrrocinia. A polyclonal antibody against the latter enzyme cross-reacted with ThcF either produced by the original Rhodococcus cells or overexpressed heterologously in Escherichia coli. In both thiocarbamate-grown Rhodococcus cells and E. coli cells expressing thcF, the haloperoxidase activity of ThcF was demonstrated. The thiocarbamate-inducible R. erythropolis ThcF protein represents the first (nonheme) haloperoxidase to be identified in a nocardioform actinomycete.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Bacterial/immunology
- Base Sequence
- Biodegradation, Environmental
- Blotting, Southern
- Blotting, Western
- Chloride Peroxidase/genetics
- Chloride Peroxidase/immunology
- Cloning, Molecular
- Cross Reactions/immunology
- Electrophoresis, Gel, Two-Dimensional
- Enzyme Induction/genetics
- Escherichia coli/genetics
- Gene Expression Regulation, Bacterial
- Molecular Sequence Data
- Peroxidases/biosynthesis
- Peroxidases/genetics
- Peroxidases/immunology
- Plasmids
- Pseudomonas/genetics
- Rhodococcus/enzymology
- Rhodococcus/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Thiocarbamates/metabolism
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Affiliation(s)
- A De Schrijver
- F.A. Janssens Laboratory of Genetics, Catholic University of Leuven, Heverlee, Belgium
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