1
|
Wu C, Goodrow S, Chen H, Li M. Distinctive biotransformation and biodefluorination of 6:2 versus 5:3 fluorotelomer carboxylic acids by municipal activated sludge. WATER RESEARCH 2024; 254:121431. [PMID: 38471201 DOI: 10.1016/j.watres.2024.121431] [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: 01/22/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/14/2024]
Abstract
Fluorotelomer carboxylic acids (FTCAs) represent an important group of per- and polyfluoroalkyl substances (PFAS) given their high toxicity, bioaccumulation potential, and frequent detection in landfill leachates and PFAS-impacted sites. In this study, we assessed the biodegradability of 6:2 FTCA and 5:3 FTCA by activated sludges from four municipal wastewater treatment plants (WWTPs) in the New York Metropolitan area. Coupling with 6:2 FTCA removal, significant fluoride release (0.56∼1.83 F-/molecule) was evident in sludge treatments during 7 days of incubation. Less-fluorinated transformation products (TPs) were formed, including 6:2 fluorotelomer unsaturated carboxylic acid (6:2 FTUCA), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), and perfluorobutanoic acid (PFBA). In contrast, little fluoride (0.01∼0.09 F-/molecule) was detected in 5:3 FTCA-dosed microcosms, though 25∼68% of initially dosed 5:3 FTCA was biologically removed. This implies the dominance of "non-fluoride-releasing pathways" that may contribute to the formation of CoA adducts or other conjugates over 5:3 FTCA biotransformation. The discovery of defluorinated 5:3 FTUCA revealed the possibility of microbial attacks of the C-F bond at the γ carbon to initiate the transformation. Microbial community analysis revealed the possible involvement of 9 genera, such as Hyphomicrobium and Dechloromonas, in aerobic FTCA biotransformation. This study unraveled that biotransformation pathways of 6:2 and 5:3 FTCAs can be divergent, resulting in biodefluorination at distinctive degrees. Further research is underscored to uncover the nontarget TPs and investigate the involved biotransformation and biodefluorination mechanisms and molecular basis.
Collapse
Affiliation(s)
- Chen Wu
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, United States
| | - Sandra Goodrow
- Division of Science and Research, New Jersey Department of Environmental Protection, Trenton, NJ, United States
| | - Hao Chen
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, United States
| | - Mengyan Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ, United States.
| |
Collapse
|
2
|
Hu M, Scott C. Toward the development of a molecular toolkit for the microbial remediation of per-and polyfluoroalkyl substances. Appl Environ Microbiol 2024; 90:e0015724. [PMID: 38477530 PMCID: PMC11022551 DOI: 10.1128/aem.00157-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024] Open
Abstract
Per- and polyfluoroalkyl substances (PFAS) are highly fluorinated synthetic organic compounds that have been used extensively in various industries owing to their unique properties. The PFAS family encompasses diverse classes, with only a fraction being commercially relevant. These substances are found in the environment, including in water sources, soil, and wildlife, leading to human exposure and fueling concerns about potential human health impacts. Although PFAS degradation is challenging, biodegradation offers a promising, eco-friendly solution. Biodegradation has been effective for a variety of organic contaminants but is yet to be successful for PFAS due to a paucity of identified microbial species capable of transforming these compounds. Recent studies have investigated PFAS biotransformation and fluoride release; however, the number of specific microorganisms and enzymes with demonstrable activity with PFAS remains limited. This review discusses enzymes that could be used in PFAS metabolism, including haloacid dehalogenases, reductive dehalogenases, cytochromes P450, alkane and butane monooxygenases, peroxidases, laccases, desulfonases, and the mechanisms of microbial resistance to intracellular fluoride. Finally, we emphasize the potential of enzyme and microbial engineering to advance PFAS degradation strategies and provide insights for future research in this field.
Collapse
Affiliation(s)
- Miao Hu
- CSIRO Environment, Black Mountain Science and Innovation Park, Canberra, ACT, Australia
| | - Colin Scott
- CSIRO Environment, Black Mountain Science and Innovation Park, Canberra, ACT, Australia
| |
Collapse
|
3
|
Khan MF, Hof C, Niemcova P, Murphy CD. Biotransformation of fluorinated drugs and xenobiotics by the model fungus Cunninghamella elegans. Methods Enzymol 2024; 696:251-285. [PMID: 38658083 DOI: 10.1016/bs.mie.2023.12.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Some species of the genus Cunninghamella (C. elegans, C. echinulata and C. blaskesleeana) produce the same phase I and phase II metabolites when incubated with xenobiotics as mammals, and thus are considered microbial models of mammalian metabolism. This had made these fungi attractive for metabolism studies with drugs, pesticides and environmental pollutants. As a substantial proportion of pharmaceuticals and agrochemicals are fluorinated, their biotransformation has been studied in Cunninghamella fungi and C. elegans in particular. This article details the methods employed for cultivating the fungi in planktonic and biofilm cultures, and extraction and analysis of fluorinated metabolites. Furthermore, protocols for the heterologous expression of Cunninghamella cytochromes P450 (CYPs), which are the enzymes associated with phase I metabolism, are described.
Collapse
Affiliation(s)
- Mohd Faheem Khan
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Carina Hof
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Patricie Niemcova
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Cormac D Murphy
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland; UCD Conway Institute, University College Dublin, Dublin, Ireland.
| |
Collapse
|
4
|
Ibrahim ARS, Mansour MK, Ahmed MMA, Ulber R, Zayed A. Metabolism of natural and synthetic bioactive compounds in Cunninghamella fungi and their applications in drug discovery. Bioorg Chem 2023; 140:106801. [PMID: 37643568 DOI: 10.1016/j.bioorg.2023.106801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/03/2023] [Accepted: 08/21/2023] [Indexed: 08/31/2023]
Abstract
Investigation of xenobiotic metabolism is a key step for drug discovery. Since the in vivo investigations may be associated with harmful effects attributed to production of toxic metabolites, it is deemed necessary to predict their structure especially at the preliminary clinical studies. Furthermore, the application of microorganisms that are capable of metabolizing drugs mimic human metabolism and consequently may predict possible metabolites. The genus Cunninghamella has been proven to be a potential candidate, which mimics xenobiotic metabolism occurring inside the human body, including phase I and II metabolic reactions. Moreover, biotransformation with Cunninghamella showed chemical diversity, where a lot of products were detected in relation to the initial substrates after being modified by oxidation, hydroxylation, and conjugation reactions. Some of these products are more bioactive than the parent compounds. The current review presents a comprehensive literature overview regarding the Cunninghamella organisms as biocatalysts, which simulate mammalian metabolism of natural secondary and synthetic compounds.
Collapse
Affiliation(s)
- Abdel-Rahim S Ibrahim
- Department of Pharmacognosy, Tanta University, Faculty of Pharmacy, El-Geish Street, Tanta 31527, Egypt
| | - Mai K Mansour
- Department of Medicinal Plants and Natural Products, Egyptian Drug Authority, Giza 11553, Egypt
| | - Mohammed M A Ahmed
- Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt; National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, University, MS 38677, United States; Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677, United States
| | - Roland Ulber
- Institute of Bioprocess Engineering, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Gottlieb-Daimler-Str. 49, Kaiserslautern 67663, Germany
| | - Ahmed Zayed
- Department of Pharmacognosy, Tanta University, Faculty of Pharmacy, El-Geish Street, Tanta 31527, Egypt; Institute of Bioprocess Engineering, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Gottlieb-Daimler-Str. 49, Kaiserslautern 67663, Germany.
| |
Collapse
|
5
|
Khan MF, Hof C, Niemcová P, Murphy CD. Recent advances in fungal xenobiotic metabolism: enzymes and applications. World J Microbiol Biotechnol 2023; 39:296. [PMID: 37658215 PMCID: PMC10474215 DOI: 10.1007/s11274-023-03737-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/23/2023] [Indexed: 09/03/2023]
Abstract
Fungi have been extensively studied for their capacity to biotransform a wide range of natural and xenobiotic compounds. This versatility is a reflection of the broad substrate specificity of fungal enzymes such as laccases, peroxidases and cytochromes P450, which are involved in these reactions. This review gives an account of recent advances in the understanding of fungal metabolism of drugs and pollutants such as dyes, agrochemicals and per- and poly-fluorinated alkyl substances (PFAS), and describes the key enzymes involved in xenobiotic biotransformation. The potential of fungi and their enzymes in the bioremediation of polluted environments and in the biocatalytic production of important compounds is also discussed.
Collapse
Affiliation(s)
- Mohd Faheem Khan
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Carina Hof
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Patricie Niemcová
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Cormac D Murphy
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
| |
Collapse
|
6
|
Khan MF, Paul Guin J, Thampi RK, Sullivan JA, Murphy CD. Enhanced removal of perfluorooctanoic acid with sequential photocatalysis and fungal treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:91478-91486. [PMID: 37474853 PMCID: PMC10439853 DOI: 10.1007/s11356-023-28588-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/30/2023] [Indexed: 07/22/2023]
Abstract
In this paper, we report the degradation of perfluorooctanoic acid (PFOA), which is a persistent contaminant in the environment that can severely impact human health, by exposing it to a photocatalyst, bismuth oxyiodide (BiOI), containing both Bi4O5I2 and Bi5O7I phases and a fungal biocatalyst (Cunninghamella elegans). Individually, the photocatalyst (after 3 h) and biocatalyst (after 48 h) degraded 35-40% of 100 ppm PFOA with 20-30% defluorination. There was a marked improvement in the degree of degradation (90%) and defluorination (60%) when PFOA was first photocatalytically treated, then exposed to the fungus. GC- and LC-MS analysis identified the products formed by the different treatments. Photocatalytic degradation of PFOA yielded short-chain perfluorocarboxylic acids, whereas fungal degradation yielded mainly 5:3 fluorotelomer carboxylic acid, which is a known inhibitor of cytochrome P450-catalysed degradation of PFAS in C. elegans. The combined treatment likely resulted in greater degradation because photocatalysis reduced the PFOA concentration without generating the inhibitory 5:3 fluorotelomer carboxylic acid, enabling the fungus to remove most of the remaining substrate. In addition, new fluorometabolites were identified that shed light on the initial catabolic steps involved in PFOA biodegradation.
Collapse
Affiliation(s)
- Mohd Faheem Khan
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield , Dublin 4, Ireland
| | - Jhimli Paul Guin
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ravindranathan K Thampi
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland
| | - James A Sullivan
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Cormac D Murphy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield , Dublin 4, Ireland.
| |
Collapse
|
7
|
Meng M, Zhai Z, Zhang Z, Kim J, Zhu Y. Metabolism of an insecticide fipronil by soil fungus Cunninghamella elegans ATCC36112. Arch Microbiol 2023; 205:264. [PMID: 37316622 DOI: 10.1007/s00203-023-03594-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/25/2023] [Accepted: 05/21/2023] [Indexed: 06/16/2023]
Abstract
In this study, the metabolic pathway of the phenylpyrazole insecticide fipronil in Cunninghamella elegans (C. elegans) was investigated. Approximately 92% of fipronil was removed within 5 days, and seven metabolites were accumulated simultaneously. The structures of the metabolites were completely or tentatively identified by GC-MS and 1H, 13C NMR. To determine the oxidative enzymes involved in metabolism, piperonyl butoxide (PB) and methimazole (MZ) were used, and the kinetic responses of fipronil and its metabolites were determined. PB strongly inhibited fipronil metabolism, while MZ weakly inhibited its metabolism. The results suggest that cytochrome P450 (CYP) and flavin-dependent monooxygenase (FMO) may participate in fipronil metabolism. Integrated metabolic pathways can be inferred from the control and inhibitor experiments. Several novel products from the fungal transformation of fipronil were identified, and similarities between C. elegans transformation and mammalian metabolism of fipronil were compared. Therefore, these results will help to gain insight into the fungal degradation of fipronil and potential applications in fipronil bioremediation. At present, microbial degradation of fipronil is the most promising approach and maintains environmental sustainability. In addition, the ability of C. elegans to mimic mammalian metabolism will assist in illustrating the metabolic fate of fipronil in mammalian hepatocytes and assess its toxicity and potential adverse effects.
Collapse
Affiliation(s)
- Min Meng
- College of Plant Health and Medicine, Qingdao Agricultural University, Changcheng Rd, Chengyang, Qingdao City, 266-109, Shandong Province, China
| | - Zhaochi Zhai
- College of Plant Health and Medicine, Qingdao Agricultural University, Changcheng Rd, Chengyang, Qingdao City, 266-109, Shandong Province, China
| | - Zhenxing Zhang
- College of Plant Health and Medicine, Qingdao Agricultural University, Changcheng Rd, Chengyang, Qingdao City, 266-109, Shandong Province, China
| | - Jeonghan Kim
- Department of Agricultural Biotechnology, Seoul National University, 599 Gwanak-ro, Silim-dong, Gwanak-Gu, Seoul, 151-742, Republic of Korea
| | - Yongzhe Zhu
- College of Chemistry and Pharmacy, Qingdao Agricultural University, Changcheng Rd, Chengyang, Qingdao City, 266-109, Shandong Province, China.
| |
Collapse
|