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Wang X, Wu Y, Chen M, Fu C, Xu H, Li L. Different Roles of Dioxin-Catabolic Plasmids in Growth, Biofilm Formation, and Metabolism of Rhodococcus sp. Strain p52. Microorganisms 2024; 12:1700. [PMID: 39203542 PMCID: PMC11357670 DOI: 10.3390/microorganisms12081700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 08/14/2024] [Accepted: 08/15/2024] [Indexed: 09/03/2024] Open
Abstract
Microorganisms harbor catabolic plasmids to tackle refractory organic pollutants, which is crucial for bioremediation and ecosystem health. Understanding the impacts of plasmids on hosts provides insights into the behavior and adaptation of degrading bacteria in the environment. Here, we examined alterations in the physiological properties and gene expression profiles of Rhodococcus sp. strain p52 after losing two conjugative dioxin-catabolic megaplasmids (pDF01 and pDF02). The growth of strain p52 accelerated after pDF01 loss, while it decelerated after pDF02 loss. During dibenzofuran degradation, the expression levels of dibenzofuran catabolic genes on pDF01 were higher compared to those on pDF02; accordingly, pDF01 loss markedly slowed dibenzofuran degradation. It was suggested that pDF01 is more beneficial to strain p52 under dibenzofuran exposure. Moreover, plasmid loss decreased biofilm formation, especially after pDF02 loss. Transcriptome profiling revealed different pathways enriched in upregulated and downregulated genes after pDF01 and pDF02 loss, indicating different adaptation mechanisms. Based on the transcriptional activity variation, pDF01 played roles in transcription and anabolic processes, while pDF02 profoundly influenced energy production and cellular defense. This study enhances our knowledge of the impacts of degradative plasmids on native hosts and the adaptation mechanisms of hosts, contributing to the application of plasmid-mediated bioremediation in contaminated environments.
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Affiliation(s)
- Xu Wang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China; (X.W.); (Y.W.); (M.C.); (C.F.); (H.X.)
| | - Yanan Wu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China; (X.W.); (Y.W.); (M.C.); (C.F.); (H.X.)
| | - Meng Chen
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China; (X.W.); (Y.W.); (M.C.); (C.F.); (H.X.)
- Marine Genomics and Biotechnology Program, Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao 266237, China
| | - Changai Fu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China; (X.W.); (Y.W.); (M.C.); (C.F.); (H.X.)
| | - Hangzhou Xu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China; (X.W.); (Y.W.); (M.C.); (C.F.); (H.X.)
| | - Li Li
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 72 Binhai Road, Qingdao 266237, China; (X.W.); (Y.W.); (M.C.); (C.F.); (H.X.)
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Aldas-Vargas A, Poursat BAJ, Sutton NB. Potential and limitations for monitoring of pesticide biodegradation at trace concentrations in water and soil. World J Microbiol Biotechnol 2022; 38:240. [PMID: 36261779 PMCID: PMC9581840 DOI: 10.1007/s11274-022-03426-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022]
Abstract
Pesticides application on agricultural fields results in pesticides being released into the environment, reaching soil, surface water and groundwater. Pesticides fate and transformation in the environment depend on environmental conditions as well as physical, chemical and biological degradation processes. Monitoring pesticides biodegradation in the environment is challenging, considering that traditional indicators, such as changes in pesticides concentration or identification of pesticide metabolites, are not suitable for many pesticides in anaerobic environments. Furthermore, those indicators cannot distinguish between biotic and abiotic pesticide degradation processes. For that reason, the use of molecular tools is important to monitor pesticide biodegradation-related genes or microorganisms in the environment. The development of targeted molecular (e.g., qPCR) tools, although laborious, allowed biodegradation monitoring by targeting the presence and expression of known catabolic genes of popular pesticides. Explorative molecular tools (i.e., metagenomics & metatranscriptomics), while requiring extensive data analysis, proved to have potential for screening the biodegradation potential and activity of more than one compound at the time. The application of molecular tools developed in laboratory and validated under controlled environments, face challenges when applied in the field due to the heterogeneity in pesticides distribution as well as natural environmental differences. However, for monitoring pesticides biodegradation in the field, the use of molecular tools combined with metadata is an important tool for understanding fate and transformation of the different pesticides present in the environment.
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Affiliation(s)
- Andrea Aldas-Vargas
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 EV, Wageningen, The Netherlands
| | - Baptiste A J Poursat
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 EV, Wageningen, The Netherlands
| | - Nora B Sutton
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 EV, Wageningen, The Netherlands.
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3
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Verdel N, Rijavec T, Rybkin I, Erzin A, Velišček Ž, Pintar A, Lapanje A. Isolation, Identification, and Selection of Bacteria With Proof-of-Concept for Bioaugmentation of Whitewater From Wood-Free Paper Mills. Front Microbiol 2021; 12:758702. [PMID: 34671337 PMCID: PMC8521037 DOI: 10.3389/fmicb.2021.758702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 09/13/2021] [Indexed: 11/13/2022] Open
Abstract
In the wood-free paper industry, whitewater is usually a mixture of additives for paper production. We are currently lacking an efficient, cost-effective purification technology for their removal. In closed whitewater cycles the additives accumulate, causing adverse production problems, such as the formation of slime and pitch. The aim of our study was to find an effective bio-based strategy for whitewater treatment using a selection of indigenous bacterial isolates. We first obtained a large collection of bacterial isolates and then tested them individually by simple plate and spectrophotometric methods for their ability to degrade the papermaking additives, i.e., carbohydrates, resin acids, alkyl ketene dimers, polyvinyl alcohol, latex, and azo and fluorescent dyes. We examined correlation between carbon source use, genera, and inoculum source of isolates using two multivariate methods: principal component analysis and FreeViz projection. Of the 318 bacterial isolates, we selected a consortium of four strains (Xanthomonadales bacterium sp. CST37-CF, Sphingomonas sp. BLA14-CF, Cellulosimicrobium sp. AKD4-BF and Aeromonas sp. RES19-BTP) that degrade the entire spectrum of tested additives by means of dissolved organic carbon measurements. A proof-of-concept study on a pilot scale was then performed by immobilizing the artificial consortium of the four strains and inserting them into a 33-liter, tubular flow-through reactor with a retention time of < 15 h. The consortium caused an 88% reduction in the COD of the whitewater, even after 21 days.
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Affiliation(s)
- Nada Verdel
- Department of Inorganic Chemistry and Technology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Tomaž Rijavec
- Department of Environmental Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Iaroslav Rybkin
- Department of Environmental Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
- Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Anja Erzin
- Faculty of Chemistry and Chemical Technology, Graduate School, University of Ljubljana, Ljubljana, Slovenia
| | | | - Albin Pintar
- Department of Inorganic Chemistry and Technology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Aleš Lapanje
- Department of Environmental Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
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Aldas-Vargas A, van der Vooren T, Rijnaarts HHM, Sutton NB. Biostimulation is a valuable tool to assess pesticide biodegradation capacity of groundwater microorganisms. CHEMOSPHERE 2021; 280:130793. [PMID: 34162094 DOI: 10.1016/j.chemosphere.2021.130793] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/12/2021] [Accepted: 05/02/2021] [Indexed: 06/13/2023]
Abstract
Groundwater is the main source for drinking water production globally. Groundwater unfortunately can contain micropollutants (MPs) such as pesticides and/or pesticide metabolites. Biological remediation of MPs in groundwater requires an understanding of natural biodegradation capacity and the conditions required to stimulate biodegradation activity. Thus, biostimulation experiments are a valuable tool to assess pesticide biodegradation capacity of field microorganisms. To this end, groundwater samples were collected at a drinking water abstraction aquifer at two locations, five different depths. Biodegradation of the MPs BAM, MCPP and 2,4-D was assessed in microcosms with groundwater samples, either without amendment, or amended with electron acceptor (nitrate or oxygen) and/or carbon substrate (dissolved organic carbon (DOC)). Oxygen + DOC was the most successful amendment resulting in complete biodegradation of 2,4-D in all microcosms after 42 days. DOC was most likely used as a growth substrate that enhanced co-metabolic 2,4-D degradation with oxygen as electron acceptor. Different biodegradation rates were observed per groundwater sample. Overall, microorganisms from the shallow aquifer had faster biodegradation rates than those from the deep aquifer. Higher microbial activity was also observed in terms of CO2 production in the microcosms with shallow groundwater. Our results seem to indicate that shallow groundwater contains more active microorganisms, possibly due to their exposure to higher concentrations of both DOC and MPs. Understanding field biodegradation capacity is a key step towards developing further bioremediation-based technologies. Our results show that biostimulation has real potential as a technology for remediating MPs in aquifers in order to ensure safe drinking production.
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Affiliation(s)
- Andrea Aldas-Vargas
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700, EV, Wageningen, the Netherlands.
| | - Thomas van der Vooren
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700, EV, Wageningen, the Netherlands.
| | - Huub H M Rijnaarts
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700, EV, Wageningen, the Netherlands.
| | - Nora B Sutton
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700, EV, Wageningen, the Netherlands.
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Nielsen TK, Horemans B, Lood C, T'Syen J, van Noort V, Lavigne R, Ellegaard-Jensen L, Hylling O, Aamand J, Springael D, Hansen LH. The complete genome of 2,6-dichlorobenzamide (BAM) degrader Aminobacter sp. MSH1 suggests a polyploid chromosome, phylogenetic reassignment, and functions of plasmids. Sci Rep 2021; 11:18943. [PMID: 34556718 PMCID: PMC8460812 DOI: 10.1038/s41598-021-98184-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/03/2021] [Indexed: 11/14/2022] Open
Abstract
Aminobacter sp. MSH1 (CIP 110285) can use the pesticide dichlobenil and its recalcitrant transformation product, 2,6-dichlorobenzamide (BAM), as sole source of carbon, nitrogen, and energy. The concentration of BAM in groundwater often exceeds the threshold limit for drinking water, requiring additional treatment in drinking water treatment plants or closure of the affected abstraction wells. Biological treatment with MSH1 is considered a potential sustainable alternative to remediate BAM-contamination in drinking water production. We present the complete genome of MSH1, which was determined independently in two institutes at Aarhus University and KU Leuven. Divergences were observed between the two genomes, i.e. one of them lacked four plasmids compared to the other. Besides the circular chromosome and the two previously described plasmids involved in BAM catabolism, pBAM1 and pBAM2, the genome of MSH1 contained two megaplasmids and three smaller plasmids. The MSH1 substrain from KU Leuven showed a reduced genome lacking a megaplasmid and three smaller plasmids and was designated substrain MK1, whereas the Aarhus variant with all plasmids was designated substrain DK1. A plasmid stability experiment indicate that substrain DK1 may have a polyploid chromosome when growing in R2B medium with more chromosomes than plasmids per cell. Finally, strain MSH1 is reassigned as Aminobacter niigataensis MSH1.
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Affiliation(s)
- Tue Kjærgaard Nielsen
- Section for Microbiology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Copenhagen, Denmark
| | - Benjamin Horemans
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001, Leuven, Belgium.,Sustainable Materials Unit, BAT Knowledge Centre, Vlaams Instituut voor Technologisch Onderzoek, Mol, Belgium
| | - Cédric Lood
- Department of Microbial and Molecular Systems (M2S), Faculty of Bioscience Engineering, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium.,Laboratory of Gene Technology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Jeroen T'Syen
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001, Leuven, Belgium
| | - Vera van Noort
- Department of Microbial and Molecular Systems (M2S), Faculty of Bioscience Engineering, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Rob Lavigne
- Laboratory of Gene Technology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Lea Ellegaard-Jensen
- Section of Environmental Microbiology and Circular Resource Flow, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Ole Hylling
- Section of Environmental Microbiology and Circular Resource Flow, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Jens Aamand
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark
| | - Dirk Springael
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001, Leuven, Belgium.
| | - Lars Hestbjerg Hansen
- Section for Microbiology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Copenhagen, Denmark.
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Turrini P, Tescari M, Visaggio D, Pirolo M, Lugli GA, Ventura M, Frangipani E, Visca P. The microbial community of a biofilm lining the wall of a pristine cave in Western New Guinea. Microbiol Res 2020; 241:126584. [DOI: 10.1016/j.micres.2020.126584] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/11/2020] [Accepted: 08/14/2020] [Indexed: 01/04/2023]
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Yang WL, Dai ZL, Cheng X, Fan ZX, Jiang HY, Dai YJ. Biotransformation of insecticide flonicamid by Aminobacter sp. CGMCC 1.17253 via nitrile hydratase catalysed hydration pathway. J Appl Microbiol 2020; 130:1571-1581. [PMID: 33030814 DOI: 10.1111/jam.14880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/10/2020] [Accepted: 09/28/2020] [Indexed: 12/11/2022]
Abstract
AIMS This study evaluates flonicamid biotransformation ability of Aminobacter sp. CGMCC 1.17253 and the enzyme catalytic mechanism involved. METHODS AND RESULTS Flonicamid transformed by resting cells of Aminobacter sp. CGMCC 1.17253 was carried out. Aminobacter sp. CGMCC 1.17253 converts flonicamid into N-(4-trifluoromethylnicotinoyl) glycinamide (TFNG-AM). Aminobacter sp. CGMCC 1.17253 transforms 31·1% of the flonicamid in a 200 mg l-1 conversion solution in 96 h. Aminobacter sp. CGMCC 1.17253 was inoculated in soil, and 72·1% of flonicamid with a concentration of 0·21 μmol g-1 was transformed in 9 days. The recombinant Escherichia coli expressing Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) and purified NHase were tested for the flonicamid transformation ability, both of them acquired the ability to transform flonicamid into TFNG-AM. CONCLUSIONS Aminobacter sp. CGMCC 1.17253 transforms flonicamid into TFNG-AM via hydration pathway mediated by cobalt-containing NHase. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report that bacteria of genus Aminobacter has flonicamid-transforming ability. This study enhances our understanding of flonicamid-degrading mechanism. Aminobacter sp. CGMCC 1.17253 has the potential for bioremediation of flonicamid pollution.
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Affiliation(s)
- W L Yang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China
| | - Z L Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China
| | - X Cheng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China
| | - Z X Fan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China
| | - H Y Jiang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China
| | - Y J Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China
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Werner J, Nour E, Bunk B, Spröer C, Smalla K, Springael D, Öztürk B. PromA Plasmids Are Instrumental in the Dissemination of Linuron Catabolic Genes Between Different Genera. Front Microbiol 2020; 11:149. [PMID: 32132980 PMCID: PMC7039861 DOI: 10.3389/fmicb.2020.00149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/22/2020] [Indexed: 01/31/2023] Open
Abstract
PromA plasmids are broad host range (BHR) plasmids, which are often cryptic and hence have an uncertain ecological role. We present three novel PromA γ plasmids which carry genes associated with degradation of the phenylurea herbicide linuron, two of which originated from unrelated Hydrogenophaga hosts isolated from different environments (pPBL-H3-2 and pBPS33-2), and one (pEN1) which was exogenously captured from an on-farm biopurification system (BPS). Hydrogenophaga sp. plasmid pBPS33-2 carries all three necessary gene clusters (hylA, dca, ccd) determining the three main steps for conversion of linuron to Krebs cycle intermediates, while pEN1 only determines the initial linuron hydrolysis step. Hydrogenophaga sp. plasmid pPBL-H3-2 exists as two variants, both containing ccd but with the hylA and dca gene modules interchanged between each other at exactly the same location. Linuron catabolic gene clusters that determine the same step were identical on all plasmids, encompassed in differently arranged constellations and characterized by the presence of multiple IS1071 elements. In all plasmids except pEN1, the insertion spot of the catabolic genes in the PromA γ plasmids was the same. Highly similar PromA plasmids carrying the linuron degrading gene cargo at the same insertion spot were previously identified in linuron degrading Variovorax sp. Interestingly, in both Hydrogenophaga populations not every PromA plasmid copy carries catabolic genes. The results indicate that PromA plasmids are important vehicles of linuron catabolic gene dissemination, rather than being cryptic and only important for the mobilization of other plasmids.
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Affiliation(s)
- Johannes Werner
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research, Rostock, Germany
| | - Eman Nour
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), Braunschweig, Germany
- Faculty of Organic Agriculture, Heliopolis University for Sustainable Development, Cairo, Egypt
| | - Boyke Bunk
- Bioinformatics Department, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Central Services, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Kornelia Smalla
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), Braunschweig, Germany
| | - Dirk Springael
- Division of Soil and Water Management, KU Leuven, Leuven, Belgium
| | - Başak Öztürk
- Division of Soil and Water Management, KU Leuven, Leuven, Belgium
- Junior Research Group Microbial Biotechnology, Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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Hylling O, Nikbakht Fini M, Ellegaard-Jensen L, Muff J, Madsen HT, Aamand J, Hansen LH. A novel hybrid concept for implementation in drinking water treatment targets micropollutant removal by combining membrane filtration with biodegradation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 694:133710. [PMID: 31756842 DOI: 10.1016/j.scitotenv.2019.133710] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 06/10/2023]
Abstract
Groundwater extracted for drinking water production is commonly treated by aeration and sand filtration. However, this simple treatment is typically unable to remove pesticide residues. As a solution, bioaugmentation of sand filter units (i.e., the addition of specific degrader strains) has been proposed as an alternative "green" technology for targeted pesticide removal. However, the introduced degraders are challenged by (i) micropollutant levels of target residue, (ii) the oligotrophic environment and (iii) competition and predation by the native microorganisms, leading to loss of population and degradation potential. To overcome these challenges, we propose the introduction of a novel hybrid treatment step to the overall treatment process in which reverse osmosis filtration and biodegradation are combined to remove a target micropollutant. Here, the reverse osmosis produces a concentrated retentate that will act as a feed to a dedicated biofilter unit, intended to promote biodegradation potential and stability of an introduced degrader. Subsequently, the purified retentate will be re-mixed with the permeate from reverse osmosis, for re-mineralization and downstream consumption. In our study, we investigated the effect of reverse osmosis retentates on the degradation potential of an introduced degrader. This paper provides the first promising results of this hybrid concept using the 2,6-dichlorobenzamide (BAM)-degrading bacteria Aminobacter sp. MSH1 in batch experiments, spiked with radiolabeled BAM. The results showed an increased degradation potential of MSH1 in retentate waters versus untreated water. Colony-forming units and qPCR showed a stable MSH1 population, despite higher concentrations of salts and metals, and increased growth of native bacteria.
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Affiliation(s)
- Ole Hylling
- Aarhus University, Dept. Environmental Science, Section for Environmental Microbiology & Biotechnology, Roskilde, Denmark
| | - Mahdi Nikbakht Fini
- Aalborg University, Dept. of Chemistry and Bioscience/Section of Chemical Engineering, Esbjerg, Denmark
| | - Lea Ellegaard-Jensen
- Aarhus University, Dept. Environmental Science, Section for Environmental Microbiology & Biotechnology, Roskilde, Denmark
| | - Jens Muff
- Aalborg University, Dept. of Chemistry and Bioscience/Section of Chemical Engineering, Esbjerg, Denmark
| | - Henrik Tækker Madsen
- Aalborg University, Dept. of Chemistry and Bioscience/Section of Chemical Engineering, Esbjerg, Denmark; Saltkraft Aps, Sønderborg, Denmark
| | - Jens Aamand
- Geological Survey of Denmark & Greenland (GEUS), Dept. of Geochemistry, Copenhagen, Denmark
| | - Lars Hestbjerg Hansen
- Aarhus University, Dept. Environmental Science, Section for Environmental Microbiology & Biotechnology, Roskilde, Denmark; University of Copenhagen, Dept. of Plant- and Environmental Science, Section for Microbial Ecology and Biotechnology, Copenhagen, Denmark.
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