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Sweeney CJ, Kaushik R, Bottoms M. Considerations for the inclusion of metabarcoding data in the plant protection product risk assessment of the soil microbiome. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2024; 20:337-358. [PMID: 37452668 DOI: 10.1002/ieam.4812] [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: 03/28/2023] [Revised: 07/12/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
There is increasing interest in further developing the plant protection product (PPP) environmental risk assessment, particularly within the European Union, to include the assessment of soil microbial community composition, as measured by metabarcoding approaches. However, to date, there has been little discussion as to how this could be implemented in a standardized, reliable, and robust manner suitable for regulatory decision-making. Introduction of metabarcoding-based assessments of the soil microbiome into the PPP risk assessment would represent a significant increase in the degree of complexity of the data that needs to be processed and analyzed in comparison to the existing risk assessment on in-soil organisms. The bioinformatics procedures to process DNA sequences into community compositional data sets currently lack standardization, while little information exists on how these data should be used to generate regulatory endpoints and the ways in which these endpoints should be interpreted. Through a thorough and critical review, we explore these challenges. We conclude that currently, we do not have a sufficient degree of standardization or understanding of the required bioinformatics and data analysis procedures to consider their use in an environmental risk assessment context. However, we highlight critical knowledge gaps and the further research required to understand whether metabarcoding-based assessments of the soil microbiome can be utilized in a statistically and ecologically relevant manner within a PPP risk assessment. Only once these challenges are addressed can we consider if and how we should use metabarcoding as a tool for regulatory decision-making to assess and monitor ecotoxicological effects on soil microorganisms within an environmental risk assessment of PPPs. Integr Environ Assess Manag 2024;20:337-358. © 2023 SETAC.
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Affiliation(s)
- Christopher J Sweeney
- Syngenta, Jealott's Hill International Research Centre Bracknell, Bracknell, Berkshire, UK
| | - Rishabh Kaushik
- Syngenta, Jealott's Hill International Research Centre Bracknell, Bracknell, Berkshire, UK
| | - Melanie Bottoms
- Syngenta, Jealott's Hill International Research Centre Bracknell, Bracknell, Berkshire, UK
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Ge R, E T, Cheng Y, Wang Y, Yu J, Li Y, Yang S. NaH 2PO 4 synergizes with organic matter to stabilize chromium in tannery sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119843. [PMID: 38128209 DOI: 10.1016/j.jenvman.2023.119843] [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: 09/26/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023]
Abstract
Heavy metal stabilization is an effective method to treat chromium in tannery sludge. Here we show that mainly investigated NaH2PO4 (MSP) and organic matter (OM) to stabilize chromium in tannery sludge. The experimental investigation revealed that the addition of montmorillonite (MMT) and MSP samples showed a significant increase in the percentage of reducible and oxidizable Cr in the former compared to the samples with the addition of MMT. This is attributed to the formation of Cr-O bond, which allows the MSP to undergo an inner-sphere complexation reaction with the metal oxide of Cr via ligand exchange. Significantly, the MSP moiety adsorbs on the surface of OM through monodentate, which increases the adsorption sites of OM for Cr6+ and promotes the reduction of Cr6+ to Cr3+. Moreover, PO43- reacts with Cr3+ to produce CrPO4 precipitation, thus reducing the free Cr3+ content. Finally, DFT calculations confirmed that a ternary system is formed between PO43-, OM, and Cr, and the binding energy is negative, which indicated that PO43- could co-stabilize Cr with OM.
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Affiliation(s)
- Ruijie Ge
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou, 121013, Liaoning, China
| | - Tao E
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou, 121013, Liaoning, China
| | - Ying Cheng
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou, 121013, Liaoning, China
| | - Yuanfei Wang
- Liaoning Huadian Environmental Testing Co., LTD, Jinzhou, 121013, Liaoning, China
| | - Jia Yu
- Environmental Protection Monitoring Station of Haining, Haining, 330481, Zhejiang, China
| | - Yun Li
- Chemistry & Chemical Engineering of College Yantai University, Yantai, 264005, Shandong, China.
| | - Shuyi Yang
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou, 121013, Liaoning, China.
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Araujo ASF, Jia X, Miranda ARL, Pereira APDA, Melo VMM, Rocha SMB, Costa RM, Saraiva TCDS, Mendes LW, Salles JF. Changes in the bacterial rare biosphere after permanent application of composted tannery sludge in a tropical soil. CHEMOSPHERE 2023; 313:137487. [PMID: 36521745 DOI: 10.1016/j.chemosphere.2022.137487] [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: 10/06/2022] [Revised: 11/21/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Composted tannery sludge (CTS) promotes shifts in soil chemical properties, affecting microbial communities. Although the effect of CTS application on the bacterial community has been studied, it is unclear whether this impact discriminates between the dominant and rare species. This present study investigated how the dominant and rare bacterial communities respond over time to different concentrations of CTS application (0, 2.5, 5, 10, and 20 tons/ha) for 180 days. The richness of operational taxonomic units (OTU) was 30-fold higher in the rare than in the dominant biosphere. While some phyla shifted their relative abundance differently in the dominant and rare biosphere, some genera increased their relative abundance under higher CTS concentrations, such as Nocardioides (∼100%), Rubrobacter (∼300%), and Nordella (∼400%). Undominated processes largely governed the dominant biosphere (76.97%), followed by homogeneous (12.51%) and variable (8.03%) selection, and to a lesser extent, the dispersal limitation (2.48%). The rare biosphere was driven by the CTS application as evidenced by the exclusively homogeneous selection (100%). This study showed that the rare biosphere was more sensitive to changes in soil chemical parameters due to CTS application, which evidences the importance explore this portion of the bacterial community for its biotechnological use in contaminated soils.
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Affiliation(s)
| | - Xiu Jia
- Microbial Ecology Cluster, Genomics Research in Ecology and Evolution in Nature (GREEN), Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen 9747AG, the Netherlands
| | | | | | | | | | | | | | - Lucas William Mendes
- Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba, SP Brazil
| | - Joana Falcão Salles
- Microbial Ecology Cluster, Genomics Research in Ecology and Evolution in Nature (GREEN), Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen 9747AG, the Netherlands
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Araujo ASF, Miranda ARL, Pereira APDA, de Melo WJ, Melo VMM, Ventura SH, Brito Junior ES, de Medeiros EV, Araujo FF, Mendes LW. Microbial communities in the rhizosphere of maize and cowpea respond differently to chromium contamination. CHEMOSPHERE 2023; 313:137417. [PMID: 36460149 DOI: 10.1016/j.chemosphere.2022.137417] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 11/18/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Chromium (Cr) contamination can affect microorganisms in the soil, but the response of the microbial community in the rhizosphere of plants grown in Cr-contaminated soils is poorly understood. Therefore, this study assessed the microbial community, by amplicon sequencing, in the rhizosphere of maize and cowpea growing in uncontaminated (∼6.0 mg kg-1 Cr) and Cr-contaminated soils (∼250 mg kg-1 Cr). Comparing Cr-contaminated and uncontaminated soils, the microbial community in the maize rhizosphere clustered separately, while the microbial community in the cowpea rhizosphere did not present clear clustering. The microbial richness ranged from ∼5000 (rhizosphere in Cr-contaminated soil) to ∼8000 OTUs (in uncontaminated soil). In the comparison of specific bacterial groups in the rhizosphere of maize, Firmicutes were enriched in Cr-contaminated soil, including Bacilli, Bacillales, and Paenibacillus. Cowpea rhizosphere showed a higher abundance of six microbial groups in Cr-contaminated soil, highlighting Rhizobiales, Pedomicrobium, and Gemmatimonadetes. The microbial community in both rhizospheres presented a similar proportion of specialists comparing uncontaminated (2.2 and 3.4% in the rhizosphere of maize and cowpea, respectively) and Cr-contaminated soils (1.8 and 3.2% in the rhizosphere of maize and cowpea, respectively). This study showed that each plant species drove differently the microbial community in the rhizosphere, with an important effect of Cr-contamination on the microbial community assembly.
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Affiliation(s)
| | | | | | - Wanderley José de Melo
- Universidade Estadual Paulista (Unesp), Faculdade de Agronomia e Veterinaria, Jaboticabal, Brazil
| | | | | | | | | | | | - Lucas William Mendes
- Centro de Energia Nuclear Na Agricultura, Universidade de Sao Paulo, Piracicaba, SP, Brazil
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Rocha SMB, do Amorim MR, Costa MKL, da Silva Saraiva TC, Costa RM, Antunes JEL, de Souza Oliveira LM, de Alcantara Neto F, de Medeiros EV, de Araujo Pereira AP, Araujo ASF. Tolerance and reduction of chromium by bacterial strains. Arch Microbiol 2022; 204:730. [DOI: 10.1007/s00203-022-03329-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/27/2022] [Accepted: 11/10/2022] [Indexed: 11/27/2022]
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Araujo ASF, de Araujo Pereira AP, Mendes LW. Applications of Cr-rich composted tannery sludge in the soil decrease microbial biomass and select specific bacterial groups. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:75113-75118. [PMID: 36085223 DOI: 10.1007/s11356-022-22933-w] [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: 06/24/2022] [Accepted: 09/04/2022] [Indexed: 06/15/2023]
Abstract
The tannery industries generate a solid waste known as tannery sludge, which is composed of organic and inorganic compounds, mainly chromium (Cr). When Cr is not removed from the tannery sludge, this solid waste is metal-rich and its application could affect the soil microorganisms. Alternatively, the composting of the tannery sludge can contribute to decreasing the concentration of Cr in the composted tannery sludge (CTS). However, in some cases, the concentration of Cr remains high in the CTS. During the last 10 years, the Cr-rich CTS has been successively applied in the soil, and its effect on soil microbial properties was verified. Here, we discuss the effect of successive applications of Cr-rich CTS on soil microbes. Interestingly, the findings have shown that successive applications of Cr-rich CTS selected specific soil microbial groups with potential functions. In addition, the studies added a new focus to further research evaluating the potential effect of successive applications of Cr-rich CTS on the rare microbial community.
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Affiliation(s)
| | | | - Lucas William Mendes
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, SP, Brazil
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Hechmi S, Hamdi H, Mokni-Tlili S, Zoghlami RI, Khelil MN, Jellali S, Benzarti S, Jedidi N. Variation of soil properties with sampling depth in two different light-textured soils after repeated applications of urban sewage sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 297:113355. [PMID: 34375225 DOI: 10.1016/j.jenvman.2021.113355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
Semi-arid agricultural soils have increasingly been subjected to urban sewage sludge (USS) applications due to accelerated soil depletion and shortages in manure supply. Research studies addressing USS reuse have mostly been conducted in cropping systems and focused on changes in topsoil properties of a given texture. Therefore, sludge-soil interactions could be largely influenced by the presence of plants, soil particle composition and depth. In this field study, two agricultural soils (sandy, S and sandy loam, SL) received simultaneously four annual USS applications of 40, 80, and 120 t ha-1 year-1 in absence of vegetation. Outcomes showed the increase of carbon and macronutrients in both soils proportionally to USS dose especially in the topsoil profile (0-20 cm). Subsoil (20-40 cm) was similarly influenced by sludge rates, showing comparable variations of fertility parameters though at significant lower levels. The depth-dependent improvement of soil fertility in both layers enhanced the microbiological properties accordingly, with significant variations in soil SL characterized by a higher clay content than soil S. Besides, positive correlations between increases in sludge dose, salinity, trace metals, and enzyme activities in both soils indicate that excessive sludge doses did not cause soil degradation or biotoxic effects under the described experimental conditions. In particular and despite high geoaccumulation indices of Ni in both soils and profiles, the global concentrations of Cu, Ni, Pb, and Zn were still below threshold levels for contaminated soils. In addition, the maintenance of pH values within neutral range and the increase of organic matter content with respect to control would have further reduced metal availability in amended soils. Therefore, we could closely investigate the effects of texture and depth on the intrinsic resilience of each soil to cope with repetitive USS applications.
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Affiliation(s)
- Sarra Hechmi
- Water Research and Technology Center, University of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
| | - Helmi Hamdi
- Center for Sustainable Development, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar.
| | - Sonia Mokni-Tlili
- Water Research and Technology Center, University of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
| | | | - Mohamed Naceur Khelil
- National Institute for Research in Rural Engineering, Water and Forestry, P.O. Box 10, Ariana, 2080, Tunisia
| | - Salah Jellali
- Center for Environmental Studies and Research, Sultan Qaboos University, P.O. Box 31, Al-Khoud 123, Muscat, Oman
| | - Saoussen Benzarti
- Lusail University, P.O. Box 9717, Jabal Thuaileb, Lusail City, Doha, Qatar
| | - Naceur Jedidi
- Water Research and Technology Center, University of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
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Ishimoto CK, Aono AH, Nagai JS, Sousa H, Miranda ARL, Melo VMM, Mendes LW, Araujo FF, de Melo WJ, Kuroshu RM, Esposito E, Araujo ASF. Microbial co-occurrence network and its key microorganisms in soil with permanent application of composted tannery sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 789:147945. [PMID: 34051496 DOI: 10.1016/j.scitotenv.2021.147945] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 06/12/2023]
Abstract
Soil microbial communities act on important environmental processes, being sensitive to the application of wastes, mainly those potential contaminants, such as tannery sludge. Due to the microbiome complexity, graph-theoretical approaches have been applied to represent model microbial communities interactions and identify important taxa, mainly in contaminated soils. Herein, we performed network and statistical analyses into microbial 16S rRNA gene sequencing data from soil samples with the application of different levels of composted tannery sludge (CTS) to assess the most connected nodes and the nodes that act as bridges to identify key microbes within each community. The network analysis revealed hubs belonging to Proteobacteria in soil with lower CTS rates, while active degraders of recalcitrant and pollutant chemical hubs belonging to Proteobacteria and Actinobacteria were found in soils under the highest CTS rates. The majority of classified connectors belonged to Actinobacteria, but similarly to hubs taxa, they shifted from metabolic functional profile to taxa with abilities to degrade toxic compounds, revealing a soil perturbation with the CTS application on community organization, which also impacted the community modularity. Members of Actinobacteria and Acidobacteria were identified as both hub and connector suggesting their role as keystone groups. Thus, these results offered us interesting insights about crucial taxa, their response to environmental alterations, and possible implications for the ecosystem.
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Affiliation(s)
| | - Alexandre Hild Aono
- Institute of Science and Technology, Universidade Federal de São Paulo, Brazil
| | - James Shiniti Nagai
- Institute of Science and Technology, Universidade Federal de São Paulo, Brazil
| | - Hério Sousa
- Institute of Science and Technology, Universidade Federal de São Paulo, Brazil
| | | | - Vania Maria Maciel Melo
- Laboratório de Ecologia Microbiana e Biotecnologia, Federal University of Ceara, Fortaleza, CE, (Brazil)
| | - Lucas William Mendes
- Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, SP, (Brazil)
| | | | - Wanderley José de Melo
- Universidade Estadual Paulista, Campus de Jaboticabal, Jaboticabal, SP, Brazil; Universidade Brasil, Descalvado, SP, Brazil
| | | | - Elisa Esposito
- Institute of Science and Technology, Universidade Federal de São Paulo, Brazil
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Hechmi S, Hamdi H, Mokni-Tlili S, Ghorbel M, Khelil MN, Zoghlami IR, Benzarti S, Jellali S, Hassen A, Jedidi N. Impact of urban sewage sludge on soil physico-chemical properties and phytotoxicity as influenced by soil texture and reuse conditions. JOURNAL OF ENVIRONMENTAL QUALITY 2020; 49:973-986. [PMID: 33016480 DOI: 10.1002/jeq2.20093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/17/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
Urban sewage sludge (USS) is increasingly applied to agricultural soils, but mixed results have been reported because of variations in reuse conditions. Most field trials have been conducted in cropping systems, which conceal intrinsic soil responses to sludge amendments due to the rhizosphere effect and farming practices. Therefore, the current field study highlights long-term changes in bare soil properties in strict relationship with soil texture and USS dose. Two agricultural soils (loamy sand [LS] and sandy [S]) were amended annually with increasing sludge rates up to 120 t ha-1 yr-1 for 5 yr under unvegetated conditions. Outcomes showed a USS dose-dependent variation of all studied parameters in topsoil samples. Soil salinization was the most significant risk related to excessive USS doses. Total dissolved salts (TDS) in saturated paste extracts reached the highest concentrations of 37.2 and 43.1 g L-1 in S soil and LS soil, respectively, treated with 120 t USS ha-1 yr-1 . This was also reflected by electrical conductivity of the saturated paste extract (ECe ) exceeding 4,000 µS cm-1 in both treatments. As observed for TDS, fertility indicators and bioavailable metals varied with soil texture due to the greater retention capacity of LS soil owing to higher fine fraction content. Soil phytotoxicity was estimated by the seed germination index (GI) calculated for lettuce, alfalfa, oat, and durum wheat. The GI was species dependent, indicating different degrees of sensitivity or tolerance to increasing USS rates. Lettuce germination was significantly affected by changes in soil conditions showing negative correlations with ECe and soluble metals. In contrast, treatment with USS enhanced the GI of wheat, reflecting higher salinity tolerance and a positive effect of sludge on abiotic conditions that control germination in soil. Therefore, the choice of adapted plant species is the key factor for successful cropping trials in sludge-amended soils.
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Affiliation(s)
- Sarra Hechmi
- Water Research and Technology Center, Univ. of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
| | - Helmi Hamdi
- Center for Sustainable Development, College of Arts and Sciences, Qatar Univ., P.O. Box 2713, Doha, Qatar
| | - Sonia Mokni-Tlili
- Water Research and Technology Center, Univ. of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
| | - Manel Ghorbel
- Water Research and Technology Center, Univ. of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
| | - Mohamed Naceur Khelil
- National Institute for Research in Rural Engineering, Water and Forestry, P.O. Box 10, Ariana, 2080, Tunisia
| | - Inès Rahma Zoghlami
- Water Research and Technology Center, Univ. of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
- Arid Regions Institute, Univ. of Gabès, Médenine, 4119, Tunisia
| | | | - Salah Jellali
- Center for Environmental Studies and Research, Sultan Qaboos Univ., P.O. Box 31, Al-Khoud 123, Muscat, Oman
| | - Abdennaceur Hassen
- Water Research and Technology Center, Univ. of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
| | - Naceur Jedidi
- Water Research and Technology Center, Univ. of Carthage, P.O. Box 273, Soliman, 8020, Tunisia
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Zhang N, Peng F, Ying GG, Van den Brink PJ. Fate and effects of triclosan in subtropical river biofilms. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 212:11-19. [PMID: 31026709 DOI: 10.1016/j.aquatox.2019.04.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/09/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
Triclosan (TCS, 5-chloro-2-(2,4-dichlorophenoxy) phenol) is a broad-spectrum antimicrobial compound. Owing to its wide use, TCS has been frequently detected in river systems, especially in the (sub-)tropics. However, little information on its interaction with river biofilm in the (sub)tropics is currently available. In the present study, subtropical river biofilms were chronically exposed to TCS for 14 d at concentrations of 0.1-100 μg/L in artificial river water, which was followed by a 7 d recovery period. The results show that 100 μg/L TCS inhibited the growth of river biofilms and the no-observed-effect concentration (NOEC) of TCS on river biofilms was 10 μg/L. The affected biofilms did not completely recover within the 7 d of recovery period due to the adsorbed TCS which was not removed together with dissolved TCS. Exposure to TCS caused significant changes in prokaryotic species composition of river biofilms but no significant effects on eukaryotic species composition. In particular, the relative abundance of several TCS-tolerant bacterial species (e.g., Pseudoxanthomonas mexicana, Sphingopyxis alaskensis and Sphingomonas wittichii) in river biofilms increased following exposure to 10 and 100 μg/L TCS. River biofilm efficiently removed TCS from the liquid phase and the pH values of the aquatic system significantly affected the removal efficiency of TCS (from 36% at pH 6.5 to 60% at pH 8.5). No degradation products were detected in the liquid phase after 5 days of exposure, possibly due to strong adsorption of the hydrophobic degradation products to river biofilms and through biodegradation by bacteria utilizing TCS and its degradation products as source of carbon and energy for growth, such as Methyloversalitis universalis and Methylobacterium aquaticum.
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Affiliation(s)
- Naisheng Zhang
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Fengjiao Peng
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Guang-Guo Ying
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou, 510006, China
| | - Paul J Van den Brink
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands; SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, Guangzhou, 510006, China; Wageningen Environmental Research, P.O. Box 47, 6700 AA, Wageningen, the Netherlands.
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