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Zhou X, Huang J, Xu S, Cheng H, Liu B, Huang J, Liu J, Pan D, Wu X. Novel Bifunctional Amidase Catalyzing the Degradation of Propanil and Aryloxyphenoxypropionate Herbicides in Rhodococcus sp. C-1. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:18067-18077. [PMID: 39082634 DOI: 10.1021/acs.jafc.4c02268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Propanil residues can contaminate habitats where microbial degradation is predominant. In this study, an efficient propanil-degrading strain C-1 was isolated from paddy and identified as Rhodococcus sp. It can completely degrade 10 μg/L-150 mg/L propanil within 0.33-10 h via the hydrolysis of the amide bond, forming 3,4-dichloroaniline. A novel bifunctional amidase, PamC, was identified in strain C-1. PamC can catalyze the hydrolysis of the amide bond of propanil to produce 3,4-dichloroaniline as well as the hydrolysis of the ester bonds of aryloxyphenoxypropionate herbicides (APPHs, clodinafop-propargyl, cyhalofop-butyl, fenoxaprop-p-ethyl, fluazifop-p-butyl, haloxyfop-p-methyl, and quizalofop-p-ethyl) to form aryloxyphenoxypropionic acids. Molecular docking and site-directed mutagenesis confirmed that the catalytic triad Lys82-Ser157-Ser181 was the active center for PamC to hydrolyze propanil and cyhalofop-butyl. This study presents a novel bifunctional amidase with capabilities for both amide and ester bond hydrolysis and enhances our understanding of the molecular mechanisms underlying the degradation of propanil and APPHs.
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Affiliation(s)
- Xiaoyu Zhou
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Jinjin Huang
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Shiwei Xu
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Huan Cheng
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Bin Liu
- College of Life Sciences, Jiangxi Normal University, Nanchang 330022, China
| | - Junwei Huang
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Junwei Liu
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Dandan Pan
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
| | - Xiangwei Wu
- Anhui Provincial Key Laboratory of Hazardous Factors and Risk Control of Agri-food Quality Safety, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China
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2
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Mao Z, Song M, Zhao R, Liu Y, Zhu Y, Liu X, Liang H, Zhang H, Wu X, Wang G, Li F, Zhang L. Characterization of two novel hydrolases from Sphingopyxis sp. DBS4 for enantioselective degradation of chiral herbicide diclofop-methyl. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:133967. [PMID: 38457978 DOI: 10.1016/j.jhazmat.2024.133967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/26/2024] [Accepted: 03/04/2024] [Indexed: 03/10/2024]
Abstract
Diclofop-methyl, an aryloxyphenoxypropionate (AOPP) herbicide, is a chiral compound with two enantiomers. Microbial detoxification and degradation of various enantiomers is garnering immense research attention. However, enantioselective catabolism of diclofop-methyl has been rarely explored, especially at the molecular level. This study cloned two novel hydrolase genes (dcmA and dcmH) in Sphingopyxis sp. DBS4, and characterized them for diclofop-methyl degradation. DcmA, a member of the amidase superfamily, exhibits 26.1-45.9% identity with functional amidases. Conversely, DcmH corresponded to the DUF3089 domain-containing protein family (a family with unknown function), sharing no significant similarity with other biochemically characterized proteins. DcmA exhibited a broad spectrum of substrates, with preferential hydrolyzation of (R)-(+)-diclofop-methyl, (R)-(+)-quizalofop-ethyl, and (R)-(+)-haloxyfop-methyl. DcmH also preferred (R)-(+)-quizalofop-ethyl and (R)-(+)-haloxyfop-methyl degradation while displaying no apparent enantioselective activity towards diclofop-methyl. Using site-directed mutagenesis and molecular docking, it was determined that Ser175 was the fundamental residue influencing DcmA's activity against the two enantiomers of diclofop-methyl. For the degradation of AOPP herbicides, DcmA is an enantioselective amidase that has never been reported in research. This study provided novel hydrolyzing enzyme resources for the remediation of diclofop-methyl in the environment and deepened the understanding of enantioselective degradation of chiral AOPP herbicides mediated by microbes.
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Affiliation(s)
- Zhenbo Mao
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Man Song
- College of Chemistry and Materials Science, Huaibei Normal University, 235000 Huaibei, China
| | - Ruiqi Zhao
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Yuan Liu
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Yumeng Zhu
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Xinyu Liu
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Hailong Liang
- Anhui Bio-breeding Engineering Research Center for Watermelon and Melon, School of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Huijun Zhang
- Anhui Bio-breeding Engineering Research Center for Watermelon and Melon, School of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Xiaomin Wu
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Guangli Wang
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Feng Li
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China
| | - Long Zhang
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, 235000 Huaibei, China; Anhui Bio-breeding Engineering Research Center for Watermelon and Melon, School of Life Sciences, Huaibei Normal University, 235000 Huaibei, China.
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3
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Liu H, Liu M, Zong X, Liu A, Yuan M, Fang S. Mechanism of safener mefenpyr-diethyl biodegradation by a newly isolated Chryseobacterium sp. B6 from wastewater sludge and application in co-contaminated soil. CHEMOSPHERE 2023; 345:140385. [PMID: 37839750 DOI: 10.1016/j.chemosphere.2023.140385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 07/14/2023] [Accepted: 10/06/2023] [Indexed: 10/17/2023]
Abstract
Safener mefenpyr-diethyl (MFD) was applied to cereal crops along with herbicides to improve herbicide selectivity for crops and weeds. However, the degradation mechanism of MFD in the environment remains unclear. One MFD-degrading bacterium, Chryseobacterium sp. B6, was isolated from activated sludge. According to Box-Behnken's optimal design, the degradation efficiency of MFD can reach 92% under conditions of pH 7.5, 30 °C, and a MFD concentration of 184 mg L-1. The degradation half-life experiment showed that a high concentration of MFD (300 mg L-1) inhibited the degradation ability of strain B6. Additionally, strain B6 was resistant to Ba2+, Cr3+, Li+, Zn2+, and Cu2+. The MFD degradation products of strain B6 were detected by GC/MS and its degradation pathway was proposed. MFD was first hydrolyzed by a hydrolase to an intermediate (RS)-1-(2,4-dichlorophenyl)-5-methyl-2-pyrazoline-5-carboxylic acid ethyl ester-3-carboxylic acid, and then further degraded by a decarboxylase to form the intermediate (RS)-1-(2,4-dichlorophenyl)-5-methyl-2-pyrazoline-5-carboxylic acid ethyl ester, finally, it is completely degraded by strain B6. Furthermore, strain B6 could effectively remove MFD from MFD-contaminated soil, and the half-life of MFD was also significantly reduced in MFD and Cu2+ co-contaminated soil after inoculating strain B6. To our knowledge, strain B6 was the first strain reported to degrade safener MFD, and this study provides a valuable candidate to remediate the co-contaminated soil with MFD and Cu2+.
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Affiliation(s)
- Hongming Liu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Anhui Normal University, Wuhu, 241000, PR China; Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, PR China.
| | - Mengna Liu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Anhui Normal University, Wuhu, 241000, PR China; Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, PR China
| | - Xuan Zong
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Anhui Normal University, Wuhu, 241000, PR China; Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, PR China
| | - Aimin Liu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Anhui Normal University, Wuhu, 241000, PR China; Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, PR China
| | - Meng Yuan
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Anhui Normal University, Wuhu, 241000, PR China; Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, Anhui Normal University, Wuhu, 241000, PR China
| | - Shangping Fang
- School of Anesthesiology, Wannan Medical College, Wuhu, Anhui, 241002, PR China.
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Phintha A, Chaiyen P. Unifying and versatile features of flavin-dependent monooxygenases: Diverse catalysis by a common C4a-(hydro)peroxyflavin. J Biol Chem 2023; 299:105413. [PMID: 37918809 PMCID: PMC10696468 DOI: 10.1016/j.jbc.2023.105413] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/18/2023] [Accepted: 10/22/2023] [Indexed: 11/04/2023] Open
Abstract
Flavin-dependent monooxygenases (FDMOs) are known for their remarkable versatility and for their crucial roles in various biological processes and applications. Extensive research has been conducted to explore the structural and functional relationships of FDMOs. The majority of reported FDMOs utilize C4a-(hydro)peroxyflavin as a reactive intermediate to incorporate an oxygen atom into a wide range of compounds. This review discusses and analyzes recent advancements in our understanding of the structural and mechanistic features governing the enzyme functions. State-of-the-art discoveries related to common and distinct structural properties governing the catalytic versatility of the C4a-(hydro)peroxyflavin intermediate in selected FDMOs are discussed. Specifically, mechanisms of hydroxylation, dehalogenation, halogenation, and light-emitting reactions by FDMOs are highlighted. We also provide new analysis based on the structural and mechanistic features of these enzymes to gain insights into how the same intermediate can be harnessed to perform a wide variety of reactions. Challenging questions to obtain further breakthroughs in the understanding of FDMOs are also proposed.
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Affiliation(s)
- Aisaraphon Phintha
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand.
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Wang W, Gong T, Li H, Liu Y, Dong Q, Zan R, Wu Y. The multi-process reaction model and underlying mechanisms of 2,4,6-trichlorophenol removal in lab-scale biochar-microorganism augmented ZVI PRBs and field-scale PRBs performance. WATER RESEARCH 2022; 217:118422. [PMID: 35413559 DOI: 10.1016/j.watres.2022.118422] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
This work developed calcium alginate (CA) embedded zero-valent iron (ZVI@CA) and CA embedded biochar (BC) immobilized microorganism (BC&Cell@CA) gel beads as alternative to conventional Fe0 permeable reactive barriers for treating groundwater contaminated with 2,4,6-trichlorophenol (2,4,6-TCP). Lab-scale and field-scale biochar-microorganism augmented PRBs (Bio-PRBs) were constructed and tested. The underlying mechanisms were revealed by a multi-source data calibrated multi-process reaction model, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high-throughput sequencing. Moreover, calibrated advection-dispersion (a) coupled with the two-site sorption (Kd) and chemical-biological multi-process reaction (λ) model were used for revealing 2,4,6-TCP transport behavior and optimizing Bio-PRBs. Compared to that in the ZVI@CA (0.004 h-1) system, the reaction rate (0.011 h-1) of 2,4,6-TCP increased by 175% in the combined chemical-biological batch system. Moreover, chemical-biological augmentation significantly improved the retardation effect of Bio-PRBs for 2,4,6-TCP. It came from that chemical-biological augmentation significantly decreased the dispersivity a (0.53 to 0.20 cm), and increased the distribution coefficient Kd (2.20 to 19.00 cm3 mg-1), the reaction rate λ (2.40 to 3.60 day-1), and the fraction (30% to 80%) of first-order kinetic sorption of 2,4,6-TCP in the lab-scale one-dimensional Bio-PRBs. Moreover, versatile functional bacteria Desulfitobacterium was crucial in the transformation of Fe (III) iron oxides. The diversity and richness of archaea in the reaction solution were improved by ZVI@CA gel beads addition. Furthermore, the field-scale reaction system was designed to remediate the chlorinated organic compounds and Benzene Toluene Ethylbenzene & Xylene contaminated groundwater in a pesticide factory site. The field test results demonstrated it is a promising technology to construct vertical reaction columns or horizontal Bio-PRBs for the efficient remediation of actually contaminated groundwater.
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Affiliation(s)
- Wenbing Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Tiantian Gong
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Hui Li
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
| | - Yiming Liu
- Department of Geography, McGill University, Montreal, QC H3A 0G4, Canada
| | - Qianling Dong
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Rixia Zan
- School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Yulin Wu
- Shanghai Geotechnical Investigations and Design Institute (SGIDI) Engineering Consulting (Group) Co. Ltd., China
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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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Pimviriyakul P, Pholert P, Somjitt S, Choowongkomon K. Role of conserved arginine in
HadA
monooxygenase for
4‐nitrophenol
and
4‐chlorophenol
detoxification. Proteins 2022; 90:1291-1302. [DOI: 10.1002/prot.26312] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 12/18/2022]
Affiliation(s)
- Panu Pimviriyakul
- Department of Biochemistry, Faculty of Science Kasetsart University Chatuchak Bangkok Thailand
| | - Patipan Pholert
- Department of Biochemistry, Faculty of Science Kasetsart University Chatuchak Bangkok Thailand
| | - Supamas Somjitt
- Department of Biochemistry, Faculty of Science Kasetsart University Chatuchak Bangkok Thailand
| | - Kiattawee Choowongkomon
- Department of Biochemistry, Faculty of Science Kasetsart University Chatuchak Bangkok Thailand
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Pimviriyakul P, Jaruwat A, Chitnumsub P, Chaiyen P. Structural insights into a flavin-dependent dehalogenase HadA explain catalysis and substrate inhibition via quadruple π-stacking. J Biol Chem 2021; 297:100952. [PMID: 34252455 PMCID: PMC8342789 DOI: 10.1016/j.jbc.2021.100952] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/24/2021] [Accepted: 07/08/2021] [Indexed: 12/20/2022] Open
Abstract
HadA is a flavin-dependent monooxygenase catalyzing hydroxylation plus dehalogenation/denitration, which is useful for biodetoxification and biodetection. In this study, the X-ray structure of wild-type HadA (HadAWT) co-complexed with reduced FAD (FADH-) and 4-nitrophenol (4NP) (HadAWT-FADH--4NP) was solved at 2.3-Å resolution, providing the first full package (with flavin and substrate bound) structure of a monooxygenase of this type. Residues Arg101, Gln158, Arg161, Thr193, Asp254, Arg233, and Arg439 constitute a flavin-binding pocket, whereas the 4NP-binding pocket contains the aromatic side chain of Phe206, which provides π-π stacking and also is a part of the hydrophobic pocket formed by Phe155, Phe286, Thr449, and Leu457. Based on site-directed mutagenesis and stopped-flow experiments, Thr193, Asp254, and His290 are important for C4a-hydroperoxyflavin formation with His290, also serving as a catalytic base for hydroxylation. We also identified a novel structural motif of quadruple π-stacking (π-π-π-π) provided by two 4NP and two Phe441 from two subunits. This motif promotes 4NP binding in a nonproductive dead-end complex, which prevents C4a-hydroperoxy-FAD formation when HadA is premixed with aromatic substrates. We also solved the structure of the HadAPhe441Val-FADH--4NP complex at 2.3-Å resolution. Although 4NP can still bind to this variant, the quadruple π-stacking motif was disrupted. All HadAPhe441 variants lack substrate inhibition behavior, confirming that quadruple π-stacking is a main cause of dead-end complex formation. Moreover, the activities of these HadAPhe441 variants were improved by ⁓20%, suggesting that insights gained from the flavin-dependent monooxygenases illustrated here should be useful for future improvement of HadA's biocatalytic applications.
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Affiliation(s)
- Panu Pimviriyakul
- Department of Biochemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Aritsara Jaruwat
- National Center for Genetic Engineering and Biotechnology, Pathumthani, Thailand
| | - Penchit Chitnumsub
- National Center for Genetic Engineering and Biotechnology, Pathumthani, Thailand.
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand.
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9
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Pimviriyakul P, Wongnate T, Tinikul R, Chaiyen P. Microbial degradation of halogenated aromatics: molecular mechanisms and enzymatic reactions. Microb Biotechnol 2020; 13:67-86. [PMID: 31565852 PMCID: PMC6922536 DOI: 10.1111/1751-7915.13488] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/01/2019] [Accepted: 09/03/2019] [Indexed: 12/12/2022] Open
Abstract
Halogenated aromatics are used widely in various industrial, agricultural and household applications. However, due to their stability, most of these compounds persist for a long time, leading to accumulation in the environment. Biological degradation of halogenated aromatics provides sustainable, low-cost and environmentally friendly technologies for removing these toxicants from the environment. This minireview discusses the molecular mechanisms of the enzymatic reactions for degrading halogenated aromatics which naturally occur in various microorganisms. In general, the biodegradation process (especially for aerobic degradation) can be divided into three main steps: upper, middle and lower metabolic pathways which successively convert the toxic halogenated aromatics to common metabolites in cells. The most difficult step in the degradation of halogenated aromatics is the dehalogenation step in the middle pathway. Although a variety of enzymes are involved in the degradation of halogenated aromatics, these various pathways all share the common feature of eventually generating metabolites for utilizing in the energy-producing metabolic pathways in cells. An in-depth understanding of how microbes employ various enzymes in biodegradation can lead to the development of new biotechnologies via enzyme/cell/metabolic engineering or synthetic biology for sustainable biodegradation processes.
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Affiliation(s)
- Panu Pimviriyakul
- Department of BiotechnologyFaculty of Engineering and Industrial TechnologySilpakorn UniversityNakhon Pathom73000Thailand
| | - Thanyaporn Wongnate
- School of Biomolecular Science and EngineeringVidyasirimedhi Institute of Science and Technology (VISTEC)Wangchan ValleyRayong21210Thailand
| | - Ruchanok Tinikul
- Department of Biochemistry and Center for Excellence in Protein and Enzyme TechnologyFaculty of ScienceMahidol UniversityBangkok10400Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and EngineeringVidyasirimedhi Institute of Science and Technology (VISTEC)Wangchan ValleyRayong21210Thailand
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10
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11
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Peng FJ, Diepens NJ, Pan CG, Ying GG, Salvito D, Selck H, Van den Brink PJ. Response of sediment bacterial community to triclosan in subtropical freshwater benthic microcosms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:676-683. [PMID: 30849585 DOI: 10.1016/j.envpol.2019.02.061] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/18/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
The response of sediment bacterial communities in subtropical freshwater benthic microcosms to sediment-associated triclosan (TCS; 28 d exposure) was analysed using Illumina high-throughput sequencing. This study highlights the interactive effects of TCS and the presence of benthic macroinvertebrates (Limnodrilus hoffmeisteri and Viviparidae bellamya) on sediment bacterial communities. Our results show that TCS alone significantly altered the taxonomic composition and decreased alpha diversity of sediment bacterial communities at concentrations ≥80 μg TCS/g dry weight (dw) sediment (sed). Regarding dominant phyla, TCS significantly reduced the relative abundance of Bacteroidetes and Firmicutes at these concentrations, whereas the relative abundance of Chloroflexi and Cyanobacteria increased. In the presence of benthic macroinvertebrates, the sediment bacterial community was affected by 8 μg TCS/g dw sed as well. However, the presence of benthic macroinvertebrates did not cause measurable changes to bacterial community in unspiked (i.e., control) sediment. These results indicate that TCS alone would not alter the sediment bacterial community at environmentally relevant concentrations (up till 8 μg/g dw sed), but may have an effect in combination with the presence of benthic macroinvertebrates. Therefore, we recommend to include benthic macroinvertebrates when assessing the response of sediment bacterial communities during exposure to environmental stress such as organic contaminants.
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Affiliation(s)
- Feng-Jiao Peng
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands.
| | - Noël J Diepens
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands
| | - Chang-Gui Pan
- School of Marine Sciences, Guangxi University, Nanning, 530004, China
| | - Guang-Guo Ying
- The Environmental Research Institute, MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou, 510006, China
| | - Daniel Salvito
- Research Institute for Fragrance Materials, 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - Henriette Selck
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Denmark
| | - Paul J Van den Brink
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands; Wageningen Environmental Research, P.O. Box 47, 6700 AA, Wageningen, the Netherlands
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