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Walter A, Caputi L, O’Connor S, van Pée KH, Ludwig-Müller J. Chlorinated Auxins-How Does Arabidopsis Thaliana Deal with Them? Int J Mol Sci 2020; 21:E2567. [PMID: 32272759 PMCID: PMC7177246 DOI: 10.3390/ijms21072567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/03/2020] [Indexed: 12/30/2022] Open
Abstract
Plant hormones have various functions in plants and play crucial roles in all developmental and differentiation stages. Auxins constitute one of the most important groups with the major representative indole-3-acetic acid (IAA). A halogenated derivate of IAA, 4-chloro-indole-3-acetic acid (4-Cl-IAA), has previously been identified in Pisum sativum and other legumes. While the enzymes responsible for the halogenation of compounds in bacteria and fungi are well studied, the metabolic pathways leading to the production of 4-Cl-IAA in plants, especially the halogenating reaction, are still unknown. Therefore, bacterial flavin-dependent tryptophan-halogenase genes were transformed into the model organism Arabidopsis thaliana. The type of chlorinated indole derivatives that could be expected was determined by incubating wild type A. thaliana with different Cl-tryptophan derivatives. We showed that, in addition to chlorinated IAA, chlorinated IAA conjugates were synthesized. Concomitantly, we found that an auxin conjugate synthetase (GH3.3 protein) from A. thaliana was able to convert chlorinated IAAs to amino acid conjugates in vitro. In addition, we showed that the production of halogenated tryptophan (Trp), indole-3-acetonitrile (IAN) and IAA is possible in transgenic A. thaliana in planta with the help of the bacterial halogenating enzymes. Furthermore, it was investigated if there is an effect (i) of exogenously applied Cl-IAA and Cl-Trp and (ii) of endogenously chlorinated substances on the growth phenotype of the plants.
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Affiliation(s)
- Antje Walter
- Institute of Botany, Technische Universität Dresden, 01062 Dresden, Germany;
| | - Lorenzo Caputi
- Department of Natural Product Synthesis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany; (L.C.); (S.O.)
| | - Sarah O’Connor
- Department of Natural Product Synthesis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany; (L.C.); (S.O.)
| | - Karl-Heinz van Pée
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany;
| | - Jutta Ludwig-Müller
- Institute of Botany, Technische Universität Dresden, 01062 Dresden, Germany;
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2
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Mao Y, Qi S, Zhao E, Yang H, Xie YF. Mechanism of ozonation enhanced formation of haloacetaldehydes during subsequent chlorination. Chemosphere 2019; 236:124361. [PMID: 31325823 DOI: 10.1016/j.chemosphere.2019.124361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/10/2019] [Accepted: 07/12/2019] [Indexed: 06/10/2023]
Abstract
Haloacetaldehydes (HAs) are the third prevalent group of disinfection by-products of great health concern. A bench-scale study was performed to investigate the formation and speciation of HAs in raw and treated waters after chlorination and ozonation-chlorination. Pre-ozonation resulted in enhanced HA formation during subsequent chlorination, and the HA yields from ozonation-chlorination were 1.66 and 1.63 times higher than that from chlorination of raw and treated waters. The mechanism about the increase of HA formation during ozonation-chlorination was systematically investigated in this study. The results showed that acetaldehyde formed after ozonation was the dominant precursor for the enhanced HA formation during subsequent chlorination. Increase in pH and chlorine dose increased HA formation during acetaldehyde chlorination. Based on the kinetic studies on the HA formation during acetaldehyde chlorination and the HA stabilities with and without free chlorine, it was found that chlorine was incorporated into the α-hydrogen in acetaldehyde to form a sequence of mono-, di- and tri-chloroacetaldehyde. During this process, these three chlorinated acetaldehydes would also undergo base-catalyzed hydrolysis through decarburization and dehalogenation pathways. This study elucidated that acetaldehyde formed after ozonation resulted in the increase of HA formation during subsequent chlorination. This study also revealed the formation pathway of HA during chlorination of acetaldehyde, which would help to minimize HA formation at drinking water plants.
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Affiliation(s)
- Yuqin Mao
- College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou, 310015, China
| | - Shengqi Qi
- School of Environment, Tsinghua University, Beijing, 100084, China.
| | - Erzhuo Zhao
- School of Environment, Tsinghua University, Beijing, 100084, China
| | - Hongwei Yang
- Research Institute for Environmental Innovation (Suzhou), Tsinghua, Suzhou, 215163, China
| | - Yuefeng F Xie
- School of Environment, Tsinghua University, Beijing, 100084, China; Environmental Engineering Programs, The Pennsylvania State University, Middletown, PA, 17057, USA
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3
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Qu R, Pan X, Li C, Liu J, Wang X, Zeng X, Wang Z. Formation of hydroxylated derivatives and coupling products from the photochemical transformation of polyfluorinated dibenzo-p-dioxins (PFDDs) on silica surfaces. Chemosphere 2019; 231:72-81. [PMID: 31128354 DOI: 10.1016/j.chemosphere.2019.05.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/29/2019] [Accepted: 05/11/2019] [Indexed: 06/09/2023]
Abstract
Polyfluorinated dibenzo-p-dioxins (PFDDs) are dioxin compounds that have been detected in industrial fluoroaromatic chemicals and can cause adverse effects to organisms. In this work, the photochemical behaviors of PFDDs congeners on silica was systematically investigated. The pseudo-first-order rate constants (k, h-1) of surface photolysis changed with the substitution number and position of fluorine atoms, and the tetra-fluorinated PFDDs tended to degrade more efficiently. Octafluorinated dibenzo-p-dioxin (OFDD) was selected as a representative to explore the reaction mechanisms. Product analysis showed that OFDD was decomposed into hydroxylated PFDDs (OH-PFDDs) and hydroxylated polyfluorinated diphenyl ethers (OH-PFDEs) via hydroxyl substitution and (OH radical mediated or direct) C-O bond cleavage. Coupling elimination reaction was also observed, resulting in the formation of three-membered and four-membered ring compounds. According to the extracted peak areas in mass spectra and the energy barrier in potential energy surface, direct homolysis of C-O bond occurs as the dominant reaction pathway. This work could provide some new insights into the environmental fate of dioxin compounds.
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Affiliation(s)
- Ruijuan Qu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
| | - Xiaoxue Pan
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Chenguang Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Jiaoqin Liu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Xinghao Wang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Xiaolan Zeng
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Zunyao Wang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
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Lörchner D, Kraus W, Köppen R. Photodegradation of the novel brominated flame retardant 2,4,6-Tris-(2,4,6-tribromophenoxy)-1,3,5-triazine in solvent system: Kinetics, photolysis products and pathway. Chemosphere 2019; 229:77-85. [PMID: 31075705 DOI: 10.1016/j.chemosphere.2019.04.184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
In this study the direct and indirect photolysis of the novel brominated flame retardant 2,4,6-Tris-(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ) in an organic solvent mixture (60:30:10, ACN:MeOH:THF) under UV-(C) and simulated sunlight irradiation was investigated, and the formed photo-transformation products were identified for the first time. TTBP-TAZ was almost completely degraded within 10 min under UV-(C) irradiation. Due to the fast degradation no specific kinetic order could be observed. In comparison, the reaction under simulated sunlight irradiation was much slower and thus, the kinetic first-order could be determined. The observed photolysis rate constant k as well as the half-life time t1/2 were estimated to be k = (0.0163 ± 0.0002) h-1 and t1/2 = 42.3 h, respectively. The addition of 2-propanol and hydrogen peroxide to investigate the influence of indirect photolysis under UV-(C) irradiation causes no influence on the degradation of TTBP-TAZ. Nevertheless, the removal of TTBP-TAZ under UV-(C) and simulated sunlight without additional chemicals (except solvent) indicates that the direct photolysis plays a significant role in the degradation mechanism of TTBP-TAZ. In both irradiation experiments, TTBP-TAZ was quantitatively degraded that involve the formation of previously unknown PTPs. Overall, two main PTPs were determined when irradiated with UV-(C) and eight sequential debromination products were observed when irradiated by simulated sunlight. These were determined by HPLC-DAD and - MS/(MS), respectively. Based on the chosen experimental conditions the consecutive debromination as well as photo-Fries rearrangement was confirmed as the main degradation pathway by high resolution mass spectrometry and X-ray diffraction.
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Affiliation(s)
- Dominique Lörchner
- Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Str. 11, D-12489, Berlin, Germany; TU Berlin, Institut für Lebensmitteltechnologie und Lebensmittelchemie, Gustav-Meyer-Allee 25, D-13305, Berlin, Germany
| | - Werner Kraus
- Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Str. 11, D-12489, Berlin, Germany
| | - Robert Köppen
- Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Str. 11, D-12489, Berlin, Germany.
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Cai WW, Peng T, Zhang JN, Hu LX, Yang B, Yang YY, Chen J, Ying GG. Degradation of climbazole by UV/chlorine process: Kinetics, transformation pathway and toxicity evaluation. Chemosphere 2019; 219:243-249. [PMID: 30543959 DOI: 10.1016/j.chemosphere.2018.12.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 05/28/2023]
Abstract
Climbazole is an antifungal agent widely used in household personal care products, and it was found persistent in chlorination disinfection process. Here we investigated the kinetics and mechanism of climbazole degradation by UV/chlorine process. The results showed that the UV/chlorine process dramatically enhanced degradation of climbazole when compared to the UV photolysis and chlorination alone. The neutral condition (pH 7) produced the highest reaction rate for the climbazole by UV/chlorine among the various pH conditions. Dissolved organic matter and inorganic ions in natural water showed moderate inhibition effects on the degradation of climbazole in the UV/chlorine process. Hydroxyl radical (OH and chlorine radical (Cl) were found to be the main reactive species in the degradation of climbazole, with the second-order rate constant of 1.24 × 1010 M-1 s-1 and 6.3 × 1010 M-1 s-1, respectively. In addition, the OH and Cl in the UV/chlorine at 100 μM accounted for 82.2% and 7.7% contributions to the removal of climbazole, respectively. Eleven of main transformation products of climbazole were identified in the UV/chlorine process. These oxidation products did not cause extra toxicity than climbazole itself. The findings from this study show that the combination of chlorination with UV photolysis could provide an effective approach for removal of climbazole during conventional disinfection process.
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Affiliation(s)
- Wen-Wen Cai
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Peng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jin-Na Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li-Xin Hu
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Bin Yang
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China.
| | - Yuan-Yuan Yang
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Jun Chen
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China
| | - Guang-Guo Ying
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, 510006, China.
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Neubauer PR, Widmann C, Wibberg D, Schröder L, Frese M, Kottke T, Kalinowski J, Niemann HH, Sewald N. A flavin-dependent halogenase from metagenomic analysis prefers bromination over chlorination. PLoS One 2018; 13:e0196797. [PMID: 29746521 PMCID: PMC5945002 DOI: 10.1371/journal.pone.0196797] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/19/2018] [Indexed: 12/04/2022] Open
Abstract
Flavin-dependent halogenases catalyse halogenation of aromatic compounds. In most cases, this reaction proceeds with high regioselectivity and requires only the presence of FADH2, oxygen, and halide salts. Since marine habitats contain high concentrations of halides, organisms populating the oceans might be valuable sources of yet undiscovered halogenases. A new Hidden-Markov-Model (HMM) based on the PFAM tryptophan halogenase model was used for the analysis of marine metagenomes. Eleven metagenomes were screened leading to the identification of 254 complete or partial putative flavin-dependent halogenase genes. One predicted halogenase gene (brvH) was selected, codon optimised for E. coli, and overexpressed. Substrate screening revealed that this enzyme represents an active flavin-dependent halogenase able to convert indole to 3-bromoindole. Remarkably, bromination prevails also in a large excess of chloride. The BrvH crystal structure is very similar to that of tryptophan halogenases but reveals a substrate binding site that is open to the solvent instead of being covered by a loop.
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Affiliation(s)
- Pia R. Neubauer
- Organic and Bioorganic Chemistry (OCIII), Bielefeld University, Bielefeld, Germany
| | - Christiane Widmann
- Structural Biochemistry (BCIV), Bielefeld University, Bielefeld, Germany
| | - Daniel Wibberg
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Lea Schröder
- Physical Chemistry (PCIII), Bielefeld University, Bielefeld, Germany
| | - Marcel Frese
- Organic and Bioorganic Chemistry (OCIII), Bielefeld University, Bielefeld, Germany
| | - Tilman Kottke
- Physical Chemistry (PCIII), Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Hartmut H. Niemann
- Structural Biochemistry (BCIV), Bielefeld University, Bielefeld, Germany
| | - Norbert Sewald
- Organic and Bioorganic Chemistry (OCIII), Bielefeld University, Bielefeld, Germany
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Zhou LY, Chen S, Li H, Guo S, Liu YD, Yang J. EDDS enhanced Shewanella putrefaciens CN32 and α-FeOOH reductive dechlorination of carbon tetrachloride. Chemosphere 2018; 198:556-564. [PMID: 29422245 DOI: 10.1016/j.chemosphere.2018.01.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
S,S-ethylenediamine-N,N-disuccinic acid (EDDS) enhanced reductive dissolution of α-FeOOH by Shewanella putrefaciens CN32 (CN32), resulting in formation of surface-bound Fe(II) species (FeIIEDDS) to improve reductive dechlorination of carbon tetrachloride (CT). The pseudo-first-order rate constants for bio-reduction extents of α-FeOOH by CN32 in the presence of 1.36 mM EDDS was 0.023 ± 0.0003 d-1 which was higher than without EDDS. The enhancement mechanism of bio-reduction was attributed to the strong complexation ability of EDDS to formed FeIIIEDDS, which could be better utilized by CN32. The dechlorination kinetic of CT by FeIIEDDS (2.016 h-1) in the presence of 1.36 mM EDDS was 24 times faster than without EDDS. Chloroform were detected as main products for the degradation of CT. The chemical analyses and morphological observation showed that combination between EDDS and Fe2+ produced FeIIEDDS complex, which had a reductive potential of -0.375 V and significantly enhanced CT dechlorination. The results showed that EDDS played an important role in enhancing the bio-reduction of α-FeOOH to accelerate reductive dechlorination of CT.
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Affiliation(s)
- Li Yang Zhou
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Shuai Chen
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Hui Li
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China; Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200239, PR China.
| | - Shu Guo
- Center for Environmental Health Research, South China Institute of Environmental Sciences, MEP, Guangzhou 510535, PR China
| | - Yong Di Liu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, PR China
| | - Jie Yang
- Research Institute of Wastes and Soil Remediation, Shanghai Academy of Environmental Sciences, Shanghai 200233, PR China.
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Zhang T, Xu B, Wang A, Cui C. Degradation kinetics of organic chloramines and formation of disinfection by-products during chlorination of creatinine. Chemosphere 2018; 195:673-682. [PMID: 29289012 DOI: 10.1016/j.chemosphere.2017.12.113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/16/2017] [Accepted: 12/18/2017] [Indexed: 06/07/2023]
Abstract
Organic chloramines can interfere with the measurement of effective combined chlorine in chlorinated water and are potential intermediate products of highly toxic disinfection by-products (DBPs). In order to know more about the degradation and transformation of organic chloramines, a typical organic chloramine precursor creatinine was selected for investigation and a corresponding individual organic chloramine chlorocreatinine was prepared in this study. The preparation condition of chlorocreatinine by chlorination was established as chlorine/creatinine = 1 M/M, reaction time = 2 h and pH = 7.0. Then the degradation kinetics of chlorocreatinine during further chlorination was studied, and a second-order rate constant of 1.16 (±0.14) M-1 s-1 was obtained at pH 7.0. Solution pH significantly influenced the degradation rate, and the elementary rate constants of chlorocreatinine with HOCl+H+, HOCl, OCl- and chlorocreatinine- with OCl- were calculated as 2.43 (±1.55) × 104 M-2 s-1, 1.05 (±0.09) M-1 s-1, 2.86 (±0.30) M-1 s-1 and 3.09 (±0.24) M-1 s-1, respectively. Besides, it was found that chlorocreatinine could be further converted into several C-DBPs (chloroform and trichloroacetone) and N-DBPs (dichloroacetonitrile (DCAN) and trichloronitromethane (TCNM)) during chlorination. The total yield of DBPs increased obviously with increasing pH, especially for TCNM. In addition, the presence of humic acid in creatinine solution could increase the formation of DCAN obviously during chlorination. Based on the UPLC-Q-TOF-MS analysis, the conversion pathways of chlorocreatinine were proposed. Several kinds of intermediate products were also identified as organic chloramines and some of them could even exist stably during the further chlorination.
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Affiliation(s)
- Tianyang Zhang
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China; State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Bin Xu
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
| | - Anqi Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Changzheng Cui
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
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Matturro B, Frascadore E, Rossetti S. High-throughput sequencing revealed novel Dehalococcoidia in dechlorinating microbial enrichments from PCB-contaminated marine sediments. FEMS Microbiol Ecol 2018; 93:4443194. [PMID: 29040506 DOI: 10.1093/femsec/fix134] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/10/2017] [Indexed: 01/07/2023] Open
Abstract
In this study, six PCE-to-ethene dechlorinating cultures, fed with a fermentable substrate (lactate) or hydrogen as electron donor, were obtained from PCB and PCE dechlorinating microcosms constructed with PCB-contaminated marine sediments. A novel Chloroflexi member (OTU-DIS1) affiliated to Dehalococcoidales Incertae Sedis, only distantly related to known dechlorinating bacteria, dominated the enrichment cultures (up to 86% of total OTUs). Sulfate-, thiosulfate- and sulfur-reducing bacteria affiliated to genera Desulfobacter, Dethiosulfatibacter and Desulfuromusa were also found to lesser extent. Remarkably, tceA, vcrA and the bifunctional PCE/PCB dehalogenase genes pcbA1, pcbA4 and pcbA5 were found in all dechlorinating microbial enrichments indicating the coexistence of different Dehalococcoides mccartyi strains. The reductive dechlorination rate in each culture remained unvaried over long-term operation (≈ 30 months) and ranged between 0.85 and 0.97 mmol Cl-1 released L-1 d-1 in the lactate-fed microbial enrichments and between 0.66 and 0.85 mmol Cl-1 released L-1 d-1 in the H2-fed microbial enrichments. Overall, this study highlights the presence of yet unexplored biodiversity in PCBs contaminated marine sediments and indicates these environments as promising sources of novel organohalide-respiring bacteria.
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Affiliation(s)
- Bruna Matturro
- Water Research Institute, IRSA-CNR, Via Salaria km 29,300, 00015 Monterotondo (RM), Italy
| | - Emanuela Frascadore
- Water Research Institute, IRSA-CNR, Via Salaria km 29,300, 00015 Monterotondo (RM), Italy
| | - Simona Rossetti
- Water Research Institute, IRSA-CNR, Via Salaria km 29,300, 00015 Monterotondo (RM), Italy
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Abstract
Hypochlorous acid and simple chloramines (RNHCl) are stable biologically derived chlorinating agents. In general, the chlorination potential of HOCl is much greater than that of RNHCl, allowing it to oxidize or chlorinate a much wider variety of reaction partners. However, in this study we demonstrate by kinetic analysis that the reactivity of RNHCl can be dramatically promoted by imidazole and histidyl model compounds via intermediary formation of the corresponding imidazole chloramines. Two biologically relevant reactions were investigated--loss of imidazole-catalyzed chlorinating capacity and phenolic ring chlorination using fluorescein and the tyrosine analog, 4-hydroxyphenylacetic acid (HPA). HOCl reacted stoichiometrically with imidazole, N-acetylhistidine (NAH), or imidazoleacetic acid to generate the corresponding imidazole chloramines which subsequently decomposed. Chloramine (NH2Cl) also underwent a markedly accelerated loss in chlorinating capacity when NAH was present, although in this case N-α-acetylhistidine chloramine (NAHCl) did not accumulate, indicating that the catalytic intermediate must be highly reactive. Mixing HOCl with 1-methylimidazole (MeIm) led to very rapid loss in chlorinating capacity via formation of a highly reactive chlorinium ion (MeImCl(+)) intermediate; this behavior suggests that the reactive forms of the analogous imidazole chloramines are their conjugate acids, e.g., the imidazolechlorinium ion (HImCl(+)). HOCl-generated imidazole chloramine (ImCl) reacted rapidly with fluorescein in a specific acid-catalyzed second-order reaction to give 3'-monochloro and 3',5'-dichloro products. Equilibrium constants for the transchlorination reactions HOCl + HIm = H2O + ImCl and NH2Cl + HIm = NH3 + ImCl were estimated from the dependence of the rate constants on [HIm]/[HOCl] and literature data. Acid catalysis again suggests that the actual chlorinating agent is HImCl(+); consistent with this interpretation, MeIm markedly catalyzed fluorescein chlorination by HOCl. Time-dependent imidazole-catalyzed HPA chlorination by NH2Cl was also demonstrated by product analyses. Quantitative assessment of the data suggests that physiological levels of histidyl groups will react with primary chloramines to generate a flux of imidazole chloramine sufficient to catalyze biological chlorination via HImCl(+), particularly in environments that generate high concentrations of HOCl such as the neutrophil phagosome.
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Affiliation(s)
- Margo D Roemeling
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis OR, USA
| | - Jared Williams
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis OR, USA
| | - Joseph S Beckman
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis OR, USA; Environmental Health Sciences Center, Oregon State University, Corvallis OR, USA; Linus Pauling Institute, Oregon State University, Corvallis OR, USA
| | - James K Hurst
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis OR, USA.
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Chen YL, Xiong L, Song XN, Wang WK, Huang YX, Yu HQ. Electrocatalytic hydrodehalogenation of atrazine in aqueous solution by Cu@Pd/Ti catalyst. Chemosphere 2015; 125:57-63. [PMID: 25697805 DOI: 10.1016/j.chemosphere.2015.01.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 06/04/2023]
Abstract
Electrocatalytic hydrodehalogenation is a cost-effective approach to degrade halogenated organic pollutants in groundwater, and Pd-based catalysts have been found to be an efficient cathode material for this purpose. In this work, a novel Cu@Pd bimetallic catalyst loaded on Ti plate was prepared via combined electrodeposition and galvanic replacement for electrocatalytic hydrodehalogenation of atrazine, a typical halogenated pollutant. The obtained bimetallic catalyst with uniformly dispersed Pd nanoparticles possessed a large electrochemically active surface area of 572 cm2. The Cu@Pd/Ti cathode exhibited a higher electrocatalytic efficiency towards atrazine reduction than the individual Pd/Ti or Cu/Ti cathodes, and achieved up to 91.5% within 120 min under a current density of 1 mA cm(-2). Such an electrocatalytic reduction followed pseudo-first-order kinetics with a rate constant of 0.0214 min(-1). Atrazine was selectively transformed to dechlorinated atrazine, and its degradation pathway was identified. Current density was found to have a critical influence on the atrazine reduction due to the competitive hydrogen evolution reaction at a higher current density. The fabricated bimetallic catalyst also exhibited a good stability. This work provides an efficient and stable electrocatalyst for chlorinated contaminate removal and groundwater remediation.
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Affiliation(s)
- Ya-Li Chen
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
| | - Lu Xiong
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
| | - Xiang-Ning Song
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
| | - Wei-Kang Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
| | - Yu-Xi Huang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
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Ueberlein S, Machill S, Niemann H, Proksch P, Brunner E. The skeletal amino acid composition of the marine demosponge Aplysina cavernicola. Mar Drugs 2014; 12:4417-38. [PMID: 25110918 PMCID: PMC4145324 DOI: 10.3390/md12084417] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 11/16/2022] Open
Abstract
It has been discovered during the past few years that demosponges of the order Verongida such as Aplysina cavernicola exhibit chitin-based skeletons. Verongida sponges are well known to produce bioactive brominated tyrosine derivatives. We could recently demonstrate that brominated compounds do not exclusively occur in the cellular matrix but also in the skeletons of the marine sponges Aplysina cavernicola and Ianthella basta. Our measurements imply that these yet unknown compounds are strongly, possibly covalently bound to the sponge skeletons. In the present work, we determined the skeletal amino acid composition of the demosponge A. cavernicola especially with respect to the presence of halogenated amino acids. The investigations of the skeletons before and after MeOH extraction confirmed that only a small amount of the brominated skeleton-bound compounds dissolves in MeOH. The main part of the brominated compounds is strongly attached to the skeletons but can be extracted for example by using Ba(OH)2. Various halogenated tyrosine derivatives were identified by GC-MS and LC-MS in these Ba(OH)2 extracts of the skeletons.
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Affiliation(s)
| | - Susanne Machill
- Bioanalytical Chemistry, TU Dresden, Dresden 01062, Germany.
| | - Hendrik Niemann
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, Universitaetsstrasse 1, Geb. 26.23, Düsseldorf 40225, Germany.
| | - Peter Proksch
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University Düsseldorf, Universitaetsstrasse 1, Geb. 26.23, Düsseldorf 40225, Germany.
| | - Eike Brunner
- Bioanalytical Chemistry, TU Dresden, Dresden 01062, Germany.
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Tredwell M, Preshlock SM, Taylor NJ, Gruber S, Huiban M, Passchier J, Mercier J, Génicot C, Gouverneur V. A general copper-mediated nucleophilic 18F fluorination of arenes. Angew Chem Int Ed Engl 2014; 53:7751-5. [PMID: 24916101 DOI: 10.1002/anie.201404436] [Citation(s) in RCA: 263] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Indexed: 11/08/2022]
Abstract
Molecules labeled with fluorine-18 are used as radiotracers for positron emission tomography. An important challenge is the labeling of arenes not amenable to aromatic nucleophilic substitution (SNAr) with [(18)F]F(-). In the ideal case, the (18)F fluorination of these substrates would be performed through reaction of [(18)F]KF with shelf-stable readily available precursors using a broadly applicable method suitable for automation. Herein, we describe the realization of these requirements with the production of (18)F arenes from pinacol-derived aryl boronic esters (arylBPin) upon treatment with [(18)F]KF/K222 and [Cu(OTf)2(py)4] (OTf = trifluoromethanesulfonate, py = pyridine). This method tolerates electron-poor and electron-rich arenes and various functional groups, and allows access to 6-[(18)F]fluoro-L-DOPA, 6-[(18)F]fluoro-m-tyrosine, and the translocator protein (TSPO) PET ligand [(18)F]DAA1106.
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Affiliation(s)
- Matthew Tredwell
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA (UK)
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Li J, Li X, Wang L, Hu Q, Sun H. C–Cl bond activation and catalytic hydrodechlorination of hexachlorobenzene by cobalt and nickel complexes with sodium formate as a reducing agent. Dalton Trans 2014; 43:6660-6. [PMID: 24626376 DOI: 10.1039/c3dt52985a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Junye Li
- School of Chemistry and Chemical Engineering, Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Shanda Nanlu 27, 250199 Jinan, PR China.
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Abstract
Highly fluorinated analogs of hydrophobic amino acids have proven to be generally effective in increasing the thermodynamic stability of proteins. These non-proteogenic amino acids can be incorporated into both α-helix and β-sheet structural motifs and generally enhance protein stability towards unfolding by heat and chemical denaturants, and retard their degradation by proteases. Recent detailed structural and thermodynamic studies have demonstrated that the increase in buried hydrophobic surface area that accompanies fluorination is primarily responsible for the stabilizing properties of fluorinated side chains. Fluorination appears to be a particularly useful strategy for increasing protein stability because fluorinated amino acids closely retain the shape of the side chain, and are thus minimally perturbing to protein structure and function. The first part of this chapter discusses some examples of highly fluorinated model proteins designed by our laboratory and protocols for their synthesis. In the second part, methods for determining their thermodynamic stability, along with conditions that have proven to be useful for crystallizing these proteins, are presented.
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Affiliation(s)
- Benjamin C Buer
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI, 48109, USA
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Banks WA, Niehoff ML, Ponzio NM, Erickson MA, Zalcman SS. Pharmacokinetics and modeling of immune cell trafficking: quantifying differential influences of target tissues versus lymphocytes in SJL and lipopolysaccharide-treated mice. J Neuroinflammation 2012; 9:231. [PMID: 23034075 PMCID: PMC3489553 DOI: 10.1186/1742-2094-9-231] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 09/17/2012] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Immune cell trafficking into the CNS and other tissues plays important roles in health and disease. Rapid quantitative methods are not available that could be used to study many of the dynamic aspects of immune cell-tissue interactions. METHODS We used pharmacokinetics and modeling to quantify and characterize the trafficking of radioactively labeled lymphocytes into brain and peripheral tissues. We used variance from two-way ANOVAs with 2 × 2 experimental designs to model the relative influences of lymphocytes and target tissues in trafficking. RESULTS We found that in male CD-1 mice, about 1 in 5,000 intravenously injected lymphocytes entered each gram of brain. Uptake by brain was 2 to 3 times higher in naïve SJL females, but uptake by spleen and clearance from blood was lower, demonstrating a dichotomy in immune cell distribution. Treatment of CD-1 mice with lipopolysaccharide (LPS) increased immune cell uptake into brain but decreased uptake by spleen and axillary nodes. CONCLUSIONS Differences in brain uptake and in uptake by spleen between SJL and CD-1 mice were primarily determined by lymphocytes, whereas differences in uptake with LPS were primarily determined by lymphocytes for the brain but by the tissues for the spleen and the axillary lymph node. These results show that immune cells normally enter the CNS and that tissues and immune cells interact in ways that can be quantified by pharmacokinetic models.
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Affiliation(s)
- William A Banks
- GRECC, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Division Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, USA
- VAPSHCS, Rm 810A, 1660 S. Columbian Way, Seattle, WA, 98108, USA
| | - Michael L Niehoff
- Division of Geriatric Medicine, Department of Internal Medicine, Saint Louis University School of Medicine, Saint Louis, MO, USA
| | - Nicholas M Ponzio
- Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, USA
| | - Michelle A Erickson
- GRECC, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Division Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, USA
- Department of Pharmacological and Physiological Sciences, Saint Louis University School of Medicine, Saint Louis, USA
| | - Steven S Zalcman
- Department of Psychiatry-UMDNJ-New Jersey Medical School, Newark, USA
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Abstract
Increased iodide intake has been linked to the development of hypothyroidism and/or autoimmune thyroiditis in humans and animals, but the mechanisms involved remain poorly understood. Increased ingestion of iodide is likely to have pleiotropic effects on either metabolic or immunological processes. Within the latter domain, recent interest has been focused on two areas: a) the role of iodinated peptides in thyroglobulin (Tg)--the molecular site of biosynthesis and storage of iodotyrosines and iodothyronines--in triggering an autoimmune cascade, and b) the role of iodine-induced apoptosis/necrosis of thyrocytes in the disease process. This review presents a brief summary of recent findings in these research areas.
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Affiliation(s)
- George Carayanniotis
- Division of Endocrinology and Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada.
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Abstract
AIMS To characterize the efficacy of widely accepted heat and chlorination on culturable and non-culturable Legionella pneumophila in starved and warm water. METHODS AND RESULTS For L. pneumophila starved for 1 day (S1), heating at 60 degrees C or more for 30 min or chlorination at 0.5-20 mg l(-1) for 60 min, a loss of 6-8 log culturability was observed, whereas only 17-47% of cells had membrane damage. Non-culturability was also observed after heating or chlorinating the cells starved for 14 days (S14). The effect of heating on membrane deterioration was reduced for S14 cells while the chlorination effect remained. Legionella pneumophila entered a non-culturable phase after being starved for 33-40 days. The disinfection effects of both heating and chlorination on non-culturable N4 and N35 cells (which were collected on the fourth and the 35th days of the non-culturability phase respectively) decreased, indicating the development of disinfection resistance among non-culturable cells that had been subjected to starvation for 1-2 months. CONCLUSIONS Heating and chlorination significantly reduce the culturability of starved L. pneumophila, and damage cell membrane to a much less extent. SIGNIFICANCE AND IMPACT OF THE STUDY This study shows the ability of long-term starved L. pneumophila to resist against disinfection treatments, which has implications in terms of public health.
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Affiliation(s)
- C-W Chang
- Institute of Environmental Health, College of Public Health, National Taiwan University, Taipei, Taiwan.
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Weinberger F, Coquempot B, Forner S, Morin P, Kloareg B, Potin P. Different regulation of haloperoxidation during agar oligosaccharide-activated defence mechanisms in two related red algae, Gracilaria sp. and Gracilaria chilensis. J Exp Bot 2007; 58:4365-4372. [PMID: 18182438 DOI: 10.1093/jxb/erm303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The related red seaweeds Gracilaria sp. from the eastern Mediterranean and Gracilaria chilensis from Chile were similar in their enzymatic inventory for halogenation. In both species, halogenation was dependent upon H(2)O(2) and thus driven by haloperoxidases. These could be inhibited with phosphate and reversibly inhibited with azide and were therefore apparently dependent upon vanadate. Both species generated in the first line bromoform and other brominated halocarbons. Gel electrophoresis under non-denaturating conditions demonstrated that both species expressed halogenating peroxidases. Elicitation of Gracilaria sp. with agar oligosaccharides resulted in marked increases in bromination, iodination, and chlorination. Production rates of volatile halocarbons and phenol red bromination both increased by a factor of eight, presumably due to increased availability for haloperoxidases of H(2)O(2) during the oxidative burst response. Elicitation of Gracilaria sp. also triggered a release of bromide ions through DIDS-sensitive anion channels, which allowed for some bromination in bromide-free medium. However, this effect was relatively limited. By contrast, agar oligosaccharide oxidation in G. chilensis did not increase halogenation. Obviously, agar oligosaccharide oxidation does not provide sufficient amounts of hypohalous acids for such increases, because it does not deliver H(2)O(2) at the active site of vanadium-dependent haloperoxidases. These results correlate with earlier findings that the agar oligosaccharide-elicited oxidative burst controls microorganisms while agar oligosaccharide oxidation does not.
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Affiliation(s)
- Florian Weinberger
- Station Biologique, UMR 7139 CNRS-UPMC and LIA DIAMS, BP74, F-29682 Roscoff, France.
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