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Zeng L, Gao J, Cui Y, Wang Z, Zhao Y, Yuan Y, Xu H, Fu X. Insight into the evolution of microbial communities and resistance genes induced by sucralose in partial nitrification system with triclosan pre-exposure. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132581. [PMID: 37741209 DOI: 10.1016/j.jhazmat.2023.132581] [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: 07/10/2023] [Revised: 09/01/2023] [Accepted: 09/17/2023] [Indexed: 09/25/2023]
Abstract
Sucralose (SUC), an artificial sweetener widely used in food, beverages and pharmaceuticals, is frequently detected in various environmental matrices. Triclosan (TCS) is commonly used as a disinfectant and often co-exists with SUC in sewage environments. This study investigated the effects of SUC (0.1-10 mg/L) on the transmission of intracellular and extracellular antibiotic resistance genes (ARGs) in the partial nitrification systems with and without TCS pre-exposure. The reactors operated for 150 days, and SUC did not affect ammonia oxidation performance, while TCS led to the maintenance of partial nitrification. The types and abundances of extracellular ARGs in sludge and free ARGs in water increased significantly after TCS pre-exposure when faced SUC stress, which might be caused by a decrease in α-Helix/(β-Sheet + Random coil). SUC was more easily to enrich ARGs in partial nitrification systems with TCS pre-exposure, exacerbating the risk of ARGs transmission. The microbial community showed stronger relationships to cope with the direct stress of SUC, and the functional bacteria (Thauera and Nitrosomonas) in TCS pre-exposure system might be potential hosts of ARGs. This study might provide insights for better understanding the fates of SUC in partial nitrification systems and the ecological risks in wastewater containing TCS and SUC. ENVIRONMENTAL IMPLICATION: Sucralose (SUC) is often detected in the environment and considered as an emerging contaminant due to its soaring consumption and environmental persistence. Triclosan (TCS) is an antibacterial agent that often co-exists with SUC in personal care products and sewage environments. During 150 d, two partial nitrification reactors with and without TCS pre-exposure were established to study the effects of SUC on nitrification performance, antibiotic resistance genes (ARGs) and microbial communities. This study showed the refractory nature of SUC, and SUC led to the transmission of extracellular ARGs in partial nitrification system with TCS pre-exposure, exacerbating the risk of ARGs dissemination.
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Affiliation(s)
- Liqin Zeng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Jingfeng Gao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
| | - Yingchao Cui
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Zhiqi Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Yifan Zhao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Yukun Yuan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Hongxin Xu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Xiaoyu Fu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
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Li X, Yang Y, Wang J, Jin H, Zhang Y, Cui Y, Song Y, Yan J. Organohalide Respiration with Diclofenac by Dehalogenimonas. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11266-11276. [PMID: 35921385 DOI: 10.1021/acs.est.1c08824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Diclofenac (DCF) is a pharmaceutically active contaminant frequently found in aquatic ecosystems. The transformation pathways and microbiology involved in the biodegradation of DCF, particularly under anoxic conditions, remain poorly understood. Here, we demonstrated microbially mediated reductive dechlorination of DCF in anaerobic enrichment culture derived from contaminated river sediment. Over 90% of the initial 76.7 ± 3.6 μM DCF was dechlorinated at a maximum rate of 1.8 ± 0.3 μM day-1 during a 160 days' incubation. Mass spectrometric analysis confirmed that 2-(2-((2-chlorophenyl)amino)phenyl)acetic acid (2-CPA) and 2-anilinophenylacetic acid (2-APA) were formed as the monochlorinated and nonchlorinated DCF transformation products, respectively. A survey of microbial composition and Sanger sequencing revealed the enrichment and dominance of a new Dehalogenimonas population, designated as Dehalogenimonas sp. strain DCF, in the DCF-dechlorinating community. Following the stoichiometric conversion of DCF to 2-CPA (76.0 ± 2.1 μM) and 2-APA (3.7 ± 0.8 μM), strain DCF cell densities increased by 24.4 ± 4.4-fold with a growth yield of 9.0 ± 0.1 × 108 cells per μmol chloride released. Our findings expand the metabolic capability in the genus Dehalogenimonas and highlight the relevant roles of organohalide-respiring bacteria for the natural attenuation of halogenated contaminants of emerging concerns (e.g., DCF).
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Affiliation(s)
- Xiuying Li
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
| | - Yi Yang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
| | - Jingjing Wang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
| | - Huijuan Jin
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaozhi Zhang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiru Cui
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yufang Song
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
| | - Jun Yan
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Room 512 South Building, 72 Wenhua Road, Shenyang, Liaoning 110016, China
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Aguilar-Romero I, van Dillewijn P, Nesme J, Sørensen SJ, Nogales R, Delgado-Moreno L, Romero E. A novel and affordable bioaugmentation strategy with microbial extracts to accelerate the biodegradation of emerging contaminants in different media. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155234. [PMID: 35427621 DOI: 10.1016/j.scitotenv.2022.155234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
This study describes a new bioaugmentation alternative based on the application of aqueous aerated extracts from a biomixture acclimated with ibuprofen, diclofenac and triclosan. This bioaugmentation strategy was assayed in biopurification systems (BPS) and in contaminated aqueous solutions to accelerate the removal of these emerging contaminants. Sterilized extracts or extracts from the initial uncontaminated biomixture were used as controls. In BPS, the dissipation of 90% of diclofenac and triclosan required, respectively, 60 and 108 days less than in the controls. The metabolite methyl-triclosan was determined at levels 12 times lower than in controls. In the bioaugmented solutions, ibuprofen was almost completely eliminated (99%) in 21 days and its hydroxylated metabolites were also determined to be at lower levels than in the controls. The plasmidome of acclimated biomixtures and its extract appeared to maintain certain types of plasmids but degradation related genes became less evident. Several dominant OTUs found in the extract identified as Flavobacterium and Fluviicola of the phylum Bacteroidetes, Thermomicrobia (phylum Chloroflexi) and Nonomuraea (phylum Actinobacteria), may be responsible for the enhanced dissipation of these contaminants. This bioaugmentation strategy represents an advantageous tool to facilitate in situ bioaugmentation.
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Affiliation(s)
- Inés Aguilar-Romero
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), C/ Profesor Albareda 1, 18008 Granada, Spain
| | - Pieter van Dillewijn
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), C/ Profesor Albareda 1, 18008 Granada, Spain
| | - Joseph Nesme
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Søren J Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Rogelio Nogales
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), C/ Profesor Albareda 1, 18008 Granada, Spain
| | - Laura Delgado-Moreno
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), C/ Profesor Albareda 1, 18008 Granada, Spain
| | - Esperanza Romero
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), C/ Profesor Albareda 1, 18008 Granada, Spain.
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Granatto CF, Grosseli GM, Sakamoto IK, Fadini PS, Varesche MBA. Influence of cosubstrate and hydraulic retention time on the removal of drugs and hygiene products in sanitary sewage in an anaerobic Expanded Granular Sludge Bed reactor. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 299:113532. [PMID: 34614559 DOI: 10.1016/j.jenvman.2021.113532] [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: 06/03/2021] [Revised: 07/24/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Diclofenac (DCF), ibuprofen (IBU), propranolol (PRO), triclosan (TCS) and linear alkylbenzene sulfonate (LAS) can be recalcitrant in Wastewater Treatment Plants (WWTP). The removal of these compounds was investigated in scale-up (69 L) Expanded Granular Sludge Bed (EGSB) reactor, fed with sanitary sewage from the São Carlos-SP (Brazil) WWTP and 200 mg L-1 of ethanol. The EGSB was operated in three phases: (I) hydraulic retention time (HRT) of 36±4 h; (II) HRT of 20±2 h and (III) HRT of 20±2 h with ethanol. Phases I and II showed no significant difference in the removal of LAS (63 ± 11-65 ± 12 %), DCF (37 ± 18-35 ± 11 %), IBU (43 ± 18-44 ± 16 %) and PRO (46 ± 25-51 ± 23 %) for 13±2-15 ± 2 mg L-1, 106 ± 32-462 ± 294 μg L-1, 166 ± 55-462 ± 213 μg L-1 and 201 ± 113-250 ± 141 μg L-1 influent, respectively. Higher TCS removal was obtained in phase I (72 ± 17 % for 127 ± 120 μg L-1 influent) when compared to phase II (51 ± 13 % for 135 ± 119 μg L-1 influent). This was due to its greater adsorption (40 %) in the initial phase. Phase III had higher removal of DCF (42 ± 10 % for 107 ± 26 μg L-1 influent), IBU (50 ± 15 % for 164 ± 47 μg L-1 influent) and TCS (85 ± 15 % for 185 ± 148 μg L-1 influent) and lower removal of LAS (35 ± 14 % for 12 ± 3 mg L-1 influent) and PRO (-142 ± 177 % for 188 ± 88 μg L-1 influent). Bacteria similar to Syntrophobacter, Smithella, Macellibacteroides, Syntrophus, Blvii28_wastewater-sludge_group and Bacteroides were identified in phase I with relative abundance of 3.1 %-4.7 %. Syntrophobacter was more abundant (15.4 %) in phase II, while in phase III, it was Smithella (12.7 %) and Caldisericum (15.1 %). Regarding the Archaea Domain, Methanosaeta was more abundant in phases I (84 %) and II (67 %), while in phase III it was Methanobacterium (86 %).
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Affiliation(s)
- Caroline F Granatto
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Ave Trabalhador São-Carlense, No. 400, Zipcode 13566-590, São Carlos, SP, Brazil.
| | - Guilherme M Grosseli
- Federal University of São Carlos, Washington LuizHighway, Km 235, Zipcode 13565-905, São Carlos, SP, Brazil.
| | - Isabel K Sakamoto
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Ave Trabalhador São-Carlense, No. 400, Zipcode 13566-590, São Carlos, SP, Brazil.
| | - Pedro S Fadini
- Federal University of São Carlos, Washington LuizHighway, Km 235, Zipcode 13565-905, São Carlos, SP, Brazil.
| | - Maria Bernadete A Varesche
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Ave Trabalhador São-Carlense, No. 400, Zipcode 13566-590, São Carlos, SP, Brazil.
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Granatto CF, Grosseli GM, Sakamoto IK, Fadini PS, Varesche MBA. Influence of metabolic cosubstrates on methanogenic potential and degradation of triclosan and propranolol in sanitary sewage. ENVIRONMENTAL RESEARCH 2021; 199:111220. [PMID: 33992637 DOI: 10.1016/j.envres.2021.111220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/27/2021] [Accepted: 04/22/2021] [Indexed: 06/12/2023]
Abstract
Triclosan (TCS) and propranolol (PRO) are emerging micropollutants that are difficult to remove in wastewater treatment plants. In this study, methanogenic potential (P) of anaerobic sludge submitted to TCS (3.6 ± 0.1 to 15.5 ± 0.1 mg L-1) and PRO (6.1 ± 0.1 to 55.9 ± 1.2 mg L-1) in sanitary sewage, was investigated in batch reactors. The use of cosubstrates (200 mg L-1 of organic matter) ethanol, methanol:ethanol and fumarate was evaluated for micropollutant degradation. Without cosubstrates, P values for 5.0 ± 0.1 mgTCS L-1, 15.5 ± 0.1 mgTCS L-1 and 55.0 ± 1.3 mgPRO L-1 were 50.53%, 98.24% and 17.66% lower in relation to Control assay (855 ± 5 μmolCH4) with sanitary sewage, without micropollutants and cosubstrates, respectively. The use of fumarate, ethanol and methanol:ethanol favored greater methane production, with P values of 2144 ± 45 μmolCH4, 2960 ± 185 μmolCH4 and 2239 ± 171 μmolCH4 for 5.1 ± 0.1 mgTCS L-1, respectively; and of 10,827 ± 185 μmolCH4, 10,946 ± 108 μmolCH4 and 10,809 ± 210 μmolCH4 for 55.0 ± 1.3 mgPRO L-1, respectively. Greater degradation of TCS (77.1 ± 0.1% for 5.1 ± 0.1 mg L-1) and PRO (24.1 ± 0.1% for 55.9 ± 1.2 mg L-1) was obtained with ethanol. However, with 28.5 ± 0.5 mg PRO L-1, greater degradation (88.4 ± 0.9%) was obtained without cosubstrates. With TCS, via sequencing of rRNA 16S gene, for Bacteria Domain, greater abundance of phylum Chloroflexi and of the genera Longilinea, Arcobacter, Mesotoga and Sulfuricurvum were identified. With PRO, the genus VadinBC27 was the most abundant. Methanosaeta was dominant in TCS with ethanol, while in PRO without cosubstrates, Methanobacterium and Methanosaeta were the most abundant. The use of metabolic cosubstrates is a favorable strategy to obtain greater methanogenic potential and degradation of TCS and PRO.
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Affiliation(s)
- Caroline F Granatto
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo. Ave Trabalhador São-Carlense, no. 400, Zipcode, 13566-590, São Carlos, SP, Brazil.
| | - Guilherme M Grosseli
- Federal University of São Carlos, Washington Luiz Highway, Km 235, Zipcode 13565-905, São Carlos, SP, Brazil.
| | - Isabel K Sakamoto
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo. Ave Trabalhador São-Carlense, no. 400, Zipcode, 13566-590, São Carlos, SP, Brazil.
| | - Pedro S Fadini
- Federal University of São Carlos, Washington Luiz Highway, Km 235, Zipcode 13565-905, São Carlos, SP, Brazil.
| | - Maria Bernadete A Varesche
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo. Ave Trabalhador São-Carlense, no. 400, Zipcode, 13566-590, São Carlos, SP, Brazil.
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Cheng X, Yun Y, Wang H, Ma L, Tian W, Man B, Liu C. Contrasting bacterial communities and their assembly processes in karst soils under different land use. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 751:142263. [PMID: 33181984 DOI: 10.1016/j.scitotenv.2020.142263] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/03/2020] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
Structure and assembly processes of soil bacterial communities under different land use at karst areas remained poorly understood to date. To address this issue, soil samples from arable land and pristine forest over a karst cave, located in the acid rain impacted area, Hubei province, were collected and subjected to high-throughput sequencing and multivariate statistical analysis. Bacterial communities and functions remarkably distinguished between soils under different land use. Both edaphic properties (the content of SO42-, C/N, pH, TN) and weathering processes, such as Si concentration, Mg/Al and Ca/Al, significantly impacted on soil bacterial community structures. Variable selections were predominant ecological processes, and pH and SO42- concentration were of significance in community assembly. Random molecular ecological network analysis revealed a more stable and complex microbial network in the forest ecosystem, which can quickly response to environmental change. Forest soil bacteria were mainly phototrophs, involving in C and N cycles, whereas those in arable soils were mainly chemoheterotrophs, capable of degrading organic fertilizers due to anthropogenic activities as confirmed by the analysis of keystone taxa, indicators and functional prediction. These results reveal that land use constructed soil bacterial communities in different aspects such as the structure, potential functions, microbial interactions and correlations with environmental variables. To our knowledge, this is the first report on bacterial community assembly in karst soils under different land use which enhances our understanding about how land use impact on microbial interaction and community assembly processes.
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Affiliation(s)
- Xiaoyu Cheng
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Yuan Yun
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hongmei Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; Laboratory of Basin Hydrology and Wetland Eco-restoration, China University of Geosciences, Wuhan 430074, China.
| | - Liyuan Ma
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Wen Tian
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Baiying Man
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; College of Life Science, Shangrao Normal University, Shangrao 334001, China
| | - Chaoyang Liu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
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Granatto CF, Grosseli GM, Sakamoto IK, Fadini PS, Varesche MBA. Methanogenic potential of diclofenac and ibuprofen in sanitary sewage using metabolic cosubstrates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 742:140530. [PMID: 32629260 DOI: 10.1016/j.scitotenv.2020.140530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Diclofenac (DCF) and ibuprofen (IBU) are widely used anti-inflammatory drugs and are frequently detected in wastewater from Wastewater Treatment Plants and in aquatic environments. In this study, the methanogenic potential (P) of anaerobic sludge subjected to DCF (7.11 ± 0.02 to 44.41 ± 0.05 mg L-1) and IBU (6.11 ± 0.01 to 42.61 ± 0.05 mg L-1), in sanitary sewage, was investigated in batch reactors. Cosubstrates (200 mg L-1 of organic matter) in the form of ethanol, methanol:ethanol and fumarate were tested separately for the removal of drugs. In the DCF assays, P was 6943 ± 121 μmolCH4, 9379 ± 259 μmolCH4, 9897 ± 212 μmolCH4 and 11,530 ± 368 μmolCH4 for control, fumarate, methanol:ethanol and ethanol conditions, respectively. In the IBU assays, under the same conditions, P was 6145 ± 101 μmolCH4, 6947 ± 66 μmolCH4, 8141 ± 191 μmolCH4and 10,583 ± 512 μmolCH4, respectively. Without cosubstrates, drug removal was below 18% for 43.10 ± 0.01 mgDCF L-1 and 43.12 ± 0.03 mgIBU L-1, respectively. Higher P and removal of DCF (28.24 ± 1.10%) and IBU (18.72 ± 1.60%) with ethanol was observed for 43.20 ± 0.01 mgDCF L-1 and 43.42 ± 0.03 mgIBU L-1, respectively. This aspect was better evidenced with DCF due to its molecular structure, a condition that resulted in a higher diversity of bacterial populations. Through the 16S rRNA sequencing, bacteria genera capable of performing aromatic ring cleavage, β-oxidation and oxidation of ethanol and fatty acids were identified. Higher relative abundance (>0.6%) was observed for Smithella, Sulfuricurvum and Synthophus for the Bacteria Domain and Methanosaeta (>79%) for the Archaea Domain. The use of ethanol favored greater mineralization of organic matter and greater methane production, which can directly assist in the metabolic pathways of microorganisms.
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Affiliation(s)
- Caroline F Granatto
- Department of Hydraulics and Sanitation Engineering, São Carlos School of Engineering, University of São Paulo, Ave Trabalhador São-Carlense, No. 400, 13566-590 São Carlos, SP, Brazil..
| | - Guilherme M Grosseli
- Federal University of São Carlos, Washington Luiz Highway, Km 235, 13565-905 São Carlos, SP, Brazil
| | - Isabel K Sakamoto
- Department of Hydraulics and Sanitation Engineering, São Carlos School of Engineering, University of São Paulo, Ave Trabalhador São-Carlense, No. 400, 13566-590 São Carlos, SP, Brazil
| | - Pedro S Fadini
- Federal University of São Carlos, Washington Luiz Highway, Km 235, 13565-905 São Carlos, SP, Brazil
| | - Maria Bernadete A Varesche
- Department of Hydraulics and Sanitation Engineering, São Carlos School of Engineering, University of São Paulo, Ave Trabalhador São-Carlense, No. 400, 13566-590 São Carlos, SP, Brazil..
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8
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Zhao S, Rogers MJ, He J. Abundance of organohalide respiring bacteria and their role in dehalogenating antimicrobials in wastewater treatment plants. WATER RESEARCH 2020; 181:115893. [PMID: 32502751 DOI: 10.1016/j.watres.2020.115893] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/25/2020] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic organohalide contaminants present in wastewater treatment plants (WWTPs) often remain untreated and can be discharged into the environment. Although organohalide respiring bacteria (OHRB) contribute to the elimination of anthropogenic organohalides in natural anaerobic environments, reductive dehalogenation by OHRB in mainstream WWTPs remains poorly understood. In this study, we quantified OHRB during a long-term operation of a municipal WWTP with short hydraulic and sludge retention times (3 h and 1.5-5 days, respectively). The obligate OHRB were detected at high levels (averaging 2.56 ± 1.73 × 107 and 3.11 ± 1.16 × 107 16S rRNA gene copies/ml MLSS sludge in anoxic and aerobic zones, respectively) over the entire sampling period and throughout the wastewater treatment train. Microcosms derived from mainstream activated sludge contained an unidentified member of the Dehalococcoides genus that metabolically dechlorinated triclosan, used as a representative emerging organohalide antimicrobial, to diclosan, suggesting the potential of anaerobic degradation of emerging contaminants in WWTPs. To further understand the mechanisms for such antimicrobials' removal, an investigation of dechlorination of triclosan by Dehalococcoides strains was conducted. Dechlorination of environmentally relevant concentrations of triclosan to diclosan was observed in Dehalococcoides mccartyi strain CG1, yielding 4.59 ± 0.34 × 108 cells/μmole Cl- removed at a rate of 0.062 μM/day and a minimal inhibitory concentration of 0.5 mg/L. Notably, both the tolerance of strain CG1 to triclosan and the rate of triclosan dechlorination increased when CG1 was cultured in the presence of both triclosan and tetrachloroethene. Taken together, our results suggest that anaerobic degradation of organohalide antimicrobials might be more prevalent in mainstream WWTPs than previously speculated, though the low growth yields that are supported by triclosan dechlorination seem to indicate that other organohalide substrates could be necessary to sustain OHRB populations in these systems.
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Affiliation(s)
- Siyan Zhao
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore
| | - Matthew J Rogers
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore.
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Mahalak KK, Firrman J, Lee JJ, Bittinger K, Nuñez A, Mattei LM, Zhang H, Fett B, Bobokalonov J, Arango-Argoty G, Zhang L, Zhang G, Liu LS. Triclosan has a robust, yet reversible impact on human gut microbial composition in vitro. PLoS One 2020; 15:e0234046. [PMID: 32585680 PMCID: PMC7316517 DOI: 10.1371/journal.pone.0234046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 05/17/2020] [Indexed: 12/17/2022] Open
Abstract
The recent ban of the antimicrobial compound triclosan from use in consumer soaps followed research that showcased the risk it poses to the environment and to human health. Triclosan has been found in human plasma, urine and milk, demonstrating that it is present in human tissues. Previous work has also demonstrated that consumption of triclosan disrupts the gut microbial community of mice and zebrafish. Due to the widespread use of triclosan and ubiquity in the environment, it is imperative to understand the impact this chemical has on the human body and its symbiotic resident microbes. To that end, this study is the first to explore how triclosan impacts the human gut microbial community in vitro both during and after treatment. Through our in vitro system simulating three regions of the human gut; the ascending colon, transverse colon, and descending colon regions, we found that treatment with triclosan significantly impacted the community structure in terms of reduced population, diversity, and metabolite production, most notably in the ascending colon region. Given a 2 week recovery period, most of the population levels, community structure, and diversity levels were recovered for all colon regions. Our results demonstrate that the human gut microbial community diversity and population size is significantly impacted by triclosan at a high dose in vitro, and that the community is recoverable within this system.
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Affiliation(s)
- Karley K. Mahalak
- United States Department of Agriculture, Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania, United States of America
| | - Jenni Firrman
- United States Department of Agriculture, Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania, United States of America
| | - Jung-Jin Lee
- Division of Gastroenterology, Hepatology, and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Kyle Bittinger
- Division of Gastroenterology, Hepatology, and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Alberto Nuñez
- United States Department of Agriculture, Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania, United States of America
| | - Lisa M. Mattei
- Division of Gastroenterology, Hepatology, and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Huanjia Zhang
- Division of Gastroenterology, Hepatology, and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Bryton Fett
- Division of Gastroenterology, Hepatology, and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Jamshed Bobokalonov
- United States Department of Agriculture, Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania, United States of America
| | - Gustavo Arango-Argoty
- Department of Computer Science, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Liqing Zhang
- Department of Computer Science, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Guodong Zhang
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts, United States of America
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Lin Shu Liu
- United States Department of Agriculture, Dairy and Functional Foods Research Unit, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania, United States of America
- * E-mail:
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10
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Fujimoto M, Carey DE, Zitomer DH, McNamara PJ. Syntroph diversity and abundance in anaerobic digestion revealed through a comparative core microbiome approach. Appl Microbiol Biotechnol 2019; 103:6353-6367. [PMID: 31161391 DOI: 10.1007/s00253-019-09862-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/04/2019] [Accepted: 04/22/2019] [Indexed: 11/27/2022]
Abstract
Anaerobic digestion is an important biotechnology treatment process for conversion of waste to energy. In this study, a comparative core microbiome approach, i.e., determining taxa that are shared in functioning digesters but not shared in non-functioning digesters, was used to determine microbial taxa that could play key roles for effective anaerobic digestion. Anaerobic digester functions were impaired by adding the broad-spectrum antimicrobial triclosan (TCS) or triclocarban (TCC) at different concentrations, and the core microbiomes in both functioning and non-functioning anaerobic digesters were compared. Digesters treated with high (2500 mg/kg) or medium (450 mg/kg) TCS and high (850 mg/kg) TCC concentrations lost their function, i.e., methane production decreased, effluent volatile fatty acid concentrations increased, and pH decreased. Changes in microbial community diversity and compositions were assessed using 16S rRNA gene amplicon sequencing. Microbial richness decreased significantly in non-functioning digesters (p < 0.001). Microbial community compositions in non-functioning digesters significantly differed from those in functioning digesters (p = 0.001, ANOSIM). Microbes identified as potentially key taxa included previously known fatty acid-degrading syntrophs and amino acid-degrading syntrophs. A diverse group of syntrophs detected in this study had low relative abundance in functioning digesters, suggesting the importance of rare microbes in anaerobic digester operation. The comparative microbiome approach used in this study can be applied to other microbial systems where a community-driven biological phenomena can be observed directly.
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Affiliation(s)
- Masanori Fujimoto
- Water Quality Center, Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA.,Soil and Water Sciences Department, Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Daniel E Carey
- Water Quality Center, Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA.,Advisian, Charlotte, NC, USA
| | - Daniel H Zitomer
- Water Quality Center, Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA
| | - Patrick J McNamara
- Water Quality Center, Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA.
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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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12
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Oh S, Choi D, Cha CJ. Ecological processes underpinning microbial community structure during exposure to subinhibitory level of triclosan. Sci Rep 2019; 9:4598. [PMID: 30872712 PMCID: PMC6418085 DOI: 10.1038/s41598-019-40936-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/21/2019] [Indexed: 11/30/2022] Open
Abstract
Ecological processes shaping the structure and diversity of microbial communities are of practical importance for managing the function and resilience of engineered biological ecosystems such as activated sludge processes. This study systematically evaluated the ecological processes acting during continuous exposure to a subinhibitory level of antimicrobial triclosan (TCS) as an environmental stressor. 16S rRNA gene-based community profiling revealed significant perturbations on the community structure and dramatic reduction (by 20-30%) in species diversity/richness compared to those under the control conditions. In addition, community profiling determined the prevalence of the deterministic processes overwhelming the ecological stochasticity. Analysis of both community composition and phenotypes in the TCS-exposed communities suggested the detailed deterministic mechanism: selection of TCS degrading (Sphingopyxis) and resistant (Pseudoxanthomonas) bacterial populations. The analysis also revealed a significant reduction of core activated sludge members, Chitinophagaceae (e.g., Ferruginibacter) and Comamonadaceae (e.g., Acidovorax), potentially affecting ecosystem functions (e.g., floc formation and nutrient removal) directly associated with system performance (i.e., wastewater treatment efficiency and effluent quality). Overall, our study provides new findings that inform the mechanisms underlying the community structure and diversity of activated sludge, which not only advances the current understanding of microbial ecology in activated sludge, but also has practical implications for the design and operation of environmental bioprocesses for treatment of antimicrobial-bearing waste streams.
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Affiliation(s)
- Seungdae Oh
- Department of Civil Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea.
| | - Donggeon Choi
- Department of Civil Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Chang-Jun Cha
- Department of Systems Biotechnology and Center for Antibiotic Resistome, Chung-Ang University, Anseong, Gyeonggi-do, Republic of Korea
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13
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Fujimoto M, Carey DE, McNamara PJ. Metagenomics reveal triclosan-induced changes in the antibiotic resistome of anaerobic digesters. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 241:1182-1190. [PMID: 30029328 DOI: 10.1016/j.envpol.2018.06.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/15/2018] [Accepted: 06/16/2018] [Indexed: 06/08/2023]
Abstract
Triclosan (TCS) is a broad-spectrum antimicrobial used in a variety of consumer products. While it was recently banned from hand soaps in the US, it is still a key ingredient in a top-selling toothpaste. TCS is a hydrophobic micropollutant that is recalcitrant under anaerobic digestion thereby resulting in high TCS concentrations in biosolids. The objective of this study was to determine the impact of TCS on the antibiotic resistome and potential cross-protection in lab-scale anaerobic digesters using shotgun metagenomics. It was hypothesized that metagenomics would reveal selection for antibiotic resistance genes (ARGs) not previously found in pure culture studies or mixed-culture studies using targeted qPCR. In this study, four different levels of TCS were continuously fed to triplicate lab-scale anaerobic digesters to assess the effect of TCS levels on the antibiotic resistance gene profiles (resistome). Blasting metagenomic reads against antibiotic/metal resistance gene database (BacMet) revealed that ARG diversity and abundance changed along the TCS concentration gradient. While loss of bacterial diversity and digester function were observed in the digester treated with the highest TCS concentration, FabV, which is a known TCS resistance gene, increased in this extremely high TCS environment. The abundance of several other known ARG or metal resistance genes (MRGs), including corA and arsB, also increased as the concentrations of TCS increased. Analysis of other functional genes using SEED database revealed the increase of potentially key genes for resistance including different types of transporters and transposons. These results indicate that antimicrobials can alter the abundance of multiple resistance genes in anaerobic digesters even when function (i.e. methane production) is maintained. This study also suggests that enriched ARGs could be released into environments with biosolids land application.
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Affiliation(s)
- Masanori Fujimoto
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA; Soil and Water Sciences Department, University of Florida, Gainesville, FL, USA
| | - Daniel E Carey
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA; Brown & Caldwell, Charlotte, NC, USA
| | - Patrick J McNamara
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA.
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14
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Holzem RM, Gardner CM, Stapleton HM, Gunsch CK. Using laboratory-generated biosolids to evaluate the microbial ecotoxicity of triclosan in a simulated land application scenario. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:11084-11099. [PMID: 29411281 DOI: 10.1007/s11356-017-1147-z] [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: 10/23/2017] [Accepted: 12/26/2017] [Indexed: 06/08/2023]
Abstract
Land application accounts for approximately 50% of wastewater solids disposal in the USA. Yet, little is known regarding the ecological impacts of many non-regulated chemicals found in biosolids. In most previous studies aimed at assessing ecological impacts, a model biosolid is generated by spiking high concentrations of the target chemical into a soil or biosolid. This approach does not account for the interaction of the chemical of interest with the solids throughout the biosolids production process (a.k.a., aging) which may impact the bioavailability and, thus, ultimate toxicity of the chemical. In the present study, using a lab-scale wastewater and digestion treatment system, we generated biosolids which contained aged triclosan and compared ecological impacts to that of spiked biosolids. Ecotoxicity was assessed based on functional and community structure changes to soil denitrifiers, microorganisms critical to nitrogen cycling. A decrease in denitrifier abundance and diversity was observed in the aged biosolids at concentrations of 17.9 ± 1.93 μg/kg while decreases in activity were observed at 26.9 ± 4.6 μg/kg. In the spiked biosolids treatment, lower denitrifier abundance, diversity, and activity were observed at triclosan (TCS) concentrations of 68.6 ± 26.9 μg/kg. This difference suggests a need to better understand TCS bioavailability dynamics.
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Affiliation(s)
- Ryan M Holzem
- Department of Natural and Applied Sciences, University of Wisconsin-Green Bay, Green Bay, WI, 54311, USA
| | - Courtney M Gardner
- Department of Civil and Environmental Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC, 27708-0287, USA
| | | | - Claudia K Gunsch
- Department of Civil and Environmental Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC, 27708-0287, USA.
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15
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Zaayman M, Siggins A, Horne D, Lowe H, Horswell J. Investigation of triclosan contamination on microbial biomass and other soil health indicators. FEMS Microbiol Lett 2017; 364:4058406. [PMID: 28859275 DOI: 10.1093/femsle/fnx163] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 08/01/2017] [Indexed: 11/14/2022] Open
Affiliation(s)
- Morkel Zaayman
- Institute of Environmental Science and Technology (ESR) Ltd, Kenepuru Science Centre, Porirua 5240, New Zealand
| | - Alma Siggins
- Institute of Environmental Science and Technology (ESR) Ltd, Kenepuru Science Centre, Porirua 5240, New Zealand
| | - Dave Horne
- Institute of Natural Resources, Massey University, Palmerston North 4442, New Zealand
| | - Hamish Lowe
- Lowe Environmental Impact, Palmerston North 4442, New Zealand
| | - Jacqui Horswell
- Institute of Environmental Science and Technology (ESR) Ltd, Kenepuru Science Centre, Porirua 5240, New Zealand
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16
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Venkiteshwaran K, Milferstedt K, Hamelin J, Zitomer DH. Anaerobic digester bioaugmentation influences quasi steady state performance and microbial community. WATER RESEARCH 2016; 104:128-136. [PMID: 27522023 DOI: 10.1016/j.watres.2016.08.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 06/06/2023]
Abstract
Nine anaerobic digesters, each seeded with biomass from a different source, were operated identically and their quasi steady state function was compared. Subsequently, digesters were bioaugmented with a methanogenic culture previously shown to increase specific methanogenic activity. Before bioaugmentation, different seed biomass resulted in different quasi steady state function, with digesters clustering into three groups distinguished by methane (CH4) production. Digesters with similar functional performance contained similar archaeal communities based on clustering of Illumina sequence data of the V4V5 region of the 16S rRNA gene. High CH4 production correlated with neutral pH and high Methanosarcina abundance, whereas low CH4 production correlated to low pH as well as high Methanobacterium and DHVEG 6 family abundance. After bioaugmentation, CH4 production from the high CH4 producing digesters transiently increased by 11 ± 3% relative to non-bioaugmented controls (p < 0.05, n = 3), whereas no functional changes were observed for medium and low CH4 producing digesters that all had pH higher than 6.7. The CH4 production increase after bioaugmentation was correlated to increased relative abundance of Methanosaeta and Methaospirillum originating from the bioaugment culture. In conclusion, different anaerobic digester seed biomass can result in different quasi steady state CH4 production, SCOD removal, pH and effluent VFA concentration in the timeframe studied. The bioaugmentation employed can result in a period of increased methane production. Future research should address extending the period of increased CH4 production by employing pH and VFA control concomitant with bioaugmentation, developing improved bioaugments, or employing a membrane bioreactor to retain the bioaugment.
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Affiliation(s)
- K Venkiteshwaran
- Department of Civil, Construction and Environmental Engineering, Marquette University, P.O. Box 1881, Milwaukee, WI 53233, USA.
| | - K Milferstedt
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France
| | - J Hamelin
- INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, Narbonne F-11100, France
| | - D H Zitomer
- Department of Civil, Construction and Environmental Engineering, Marquette University, P.O. Box 1881, Milwaukee, WI 53233, USA
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17
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Nijenhuis I, Kuntze K. Anaerobic microbial dehalogenation of organohalides — state of the art and remediation strategies. Curr Opin Biotechnol 2016; 38:33-8. [DOI: 10.1016/j.copbio.2015.11.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/03/2015] [Indexed: 11/26/2022]
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18
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Le Pogam P, Boustie J. Xanthones of Lichen Source: A 2016 Update. Molecules 2016; 21:294. [PMID: 26950106 PMCID: PMC6273661 DOI: 10.3390/molecules21030294] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/21/2016] [Accepted: 02/23/2016] [Indexed: 11/23/2022] Open
Abstract
An update of xanthones encountered in lichens is proposed as more than 20 new xanthones have been described since the publication of the compendium of lichen metabolites by Huneck and Yoshimura in 1996. The last decades witnessed major advances regarding the elucidation of biosynthetic schemes leading to these fascinating compounds, accounting for the unique substitution patterns of a very vast majority of lichen xanthones. Besides a comprehensive analysis of the structures of xanthones described in lichens, their bioactivities and the emerging analytical strategies used to pinpoint them within lichens are presented here together with physico-chemical properties (including NMR data) as reported since 1996.
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Affiliation(s)
- Pierre Le Pogam
- Laboratoire de Pharmacognosie, Equipe PNSCM, (ISCR UMR CNRS 6226), Faculté des Sciences Pharmaceutiques et Biologiques, 2 Avenue du Professeur Léon Bernard, 35043, Rennes Cédex, France.
| | - Joël Boustie
- Laboratoire de Pharmacognosie, Equipe PNSCM, (ISCR UMR CNRS 6226), Faculté des Sciences Pharmaceutiques et Biologiques, 2 Avenue du Professeur Léon Bernard, 35043, Rennes Cédex, France.
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19
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Carey DE, Zitomer DH, Hristova KR, Kappell AD, McNamara PJ. Triclocarban Influences Antibiotic Resistance and Alters Anaerobic Digester Microbial Community Structure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:126-134. [PMID: 26588246 DOI: 10.1021/acs.est.5b03080] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Triclocarban (TCC) is one of the most abundant organic micropollutants detected in biosolids. Lab-scale anaerobic digesters were amended with TCC at concentrations ranging from the background concentration of seed biosolids (30 mg/kg) to toxic concentrations of 850 mg/kg to determine the effect on methane production, relative abundance of antibiotic resistance genes, and microbial community structure. Additionally, the TCC addition rate was varied to determine the impacts of acclimation time. At environmentally relevant TCC concentrations (max detect = 440 mg/kg), digesters maintained function. Digesters receiving 450 mg/kg of TCC maintained function under gradual TCC addition, but volatile fatty acid concentrations increased, pH decreased, and methane production ceased when immediately fed this concentration. The concentrations of the mexB gene (encoding for a multidrug efflux pump) were higher with all concentrations of TCC compared to a control, but higher TCC concentrations did not correlate with increased mexB abundance. The relative abundance of the gene tet(L) was greater in the digesters that no longer produced methane, and no effect on the relative abundance of the class 1 integron integrase encoding gene (intI1) was observed. Illumina sequencing revealed substantial community shifts in digesters that functionally failed from increased levels of TCC. More subtle, yet significant, community shifts were observed in digesters amended with TCC levels that did not inhibit function. This research demonstrates that TCC can select for a multidrug resistance encoding gene in mixed community anaerobic environments, and this selection occurs at concentrations (30 mg/kg) that can be found in full-scale anaerobic digesters (U.S. median concentration = 22 mg/kg, mean = 39 mg/kg).
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Affiliation(s)
- Daniel E Carey
- Department of Civil, Construction, and Environmental Engineering, 1637 West Wisconsin Avenue, Marquette University , Milwaukee 53213, Wisconsin, United States
| | - Daniel H Zitomer
- Department of Civil, Construction, and Environmental Engineering, 1637 West Wisconsin Avenue, Marquette University , Milwaukee 53213, Wisconsin, United States
| | - Krassimira R Hristova
- Department of Biological Sciences, Marquette University , 530 N. 15th Street, Milwaukee 53213, Wisconsin, United States
| | - Anthony D Kappell
- Department of Biological Sciences, Marquette University , 530 N. 15th Street, Milwaukee 53213, Wisconsin, United States
| | - Patrick J McNamara
- Department of Civil, Construction, and Environmental Engineering, 1637 West Wisconsin Avenue, Marquette University , Milwaukee 53213, Wisconsin, United States
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20
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Smith BJ, Boothe MA, Fiddler BA, Lozano TM, Rahi RK, Krzmarzick MJ. Enumeration of Organohalide Respirers in Municipal Wastewater Anaerobic Digesters. Microbiol Insights 2015; 8:9-14. [PMID: 26508873 PMCID: PMC4607082 DOI: 10.4137/mbi.s31445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/10/2015] [Accepted: 09/15/2015] [Indexed: 01/01/2023] Open
Abstract
Organohalide contaminants such as triclosan and triclocarban have been well documented in municipal wastewater treatment plants (WWTPs), but the degradation of these contaminants is not well understood. One possible removal mechanism is organohalide respiration by which bacteria reduce the halogenated compound. The purpose of this study was to determine the abundance of organohalide-respiring bacteria in eight WWTP anaerobic digesters. The obligate organohalide respiring Dehalococcoides mccartyi was the most abundant and averaged 3.3 × 107 copies of 16S rRNA genes per gram, while the Dehalobacter was much lower at 2.6 × 104 copies of 16S rRNA genes per gram. The genus Sulfurospirillum spp. was also detected at 1.0 × 107 copies of 16S rRNA genes per gram. No other known or putatively organohalide-respiring strains in the Dehalococcoidaceae family were found to be present nor were the genera Desulfitobacterium or Desulfomonile.
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Affiliation(s)
- Bryan Jk Smith
- School of Civil and Environmental Engineering, College of Engineering, Architecture and Technology, Oklahoma State University, Stillwater, OK, USA
| | - Melissa A Boothe
- School of Civil and Environmental Engineering, College of Engineering, Architecture and Technology, Oklahoma State University, Stillwater, OK, USA
| | - Brice A Fiddler
- School of Civil and Environmental Engineering, College of Engineering, Architecture and Technology, Oklahoma State University, Stillwater, OK, USA
| | - Tania M Lozano
- School of Civil and Environmental Engineering, College of Engineering, Architecture and Technology, Oklahoma State University, Stillwater, OK, USA
| | - Russel K Rahi
- School of Civil and Environmental Engineering, College of Engineering, Architecture and Technology, Oklahoma State University, Stillwater, OK, USA
| | - Mark J Krzmarzick
- School of Civil and Environmental Engineering, College of Engineering, Architecture and Technology, Oklahoma State University, Stillwater, OK, USA
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21
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McNamara PJ, LaPara TM, Novak PJ. The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function. Microbiol Insights 2015; 8:1-7. [PMID: 26462249 PMCID: PMC4589087 DOI: 10.4137/mbi.s31345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/01/2015] [Accepted: 09/02/2015] [Indexed: 11/30/2022] Open
Abstract
A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both short-term (14 days) and long-term (140 days) studies to determine the impact of exposure time. Additionally, triclosan was added during the experiments to investigate the impact of mixtures on community structure and function. PFOS did not alter methane production in short-term studies, but in long-term studies, methane production increased, consistent with our hypothesis that PFOS may act as a metabolic uncoupler. The impact of triclosan on methane production was exacerbated when PFOS was already present in the anaerobic enrichment cultures. Triclosan also had greater impacts on microbial community structures in the bottles that had been exposed to PFOS long-term. These results demonstrate that both chemical mixtures and exposure time are important parameters to address when trying to define the impacts of micropollutants on anaerobic microbial communities.
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Affiliation(s)
- Patrick J McNamara
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Timothy M LaPara
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Paige J Novak
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, Minneapolis, MN, USA
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Carey DE, McNamara PJ. The impact of triclosan on the spread of antibiotic resistance in the environment. Front Microbiol 2015; 5:780. [PMID: 25642217 PMCID: PMC4295542 DOI: 10.3389/fmicb.2014.00780] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 12/19/2014] [Indexed: 12/22/2022] Open
Abstract
Triclosan (TCS) is a commonly used antimicrobial agent that enters wastewater treatment plants (WWTPs) and the environment. An estimated 1.1 × 10(5) to 4.2 × 10(5) kg of TCS are discharged from these WWTPs per year in the United States. The abundance of TCS along with its antimicrobial properties have given rise to concern regarding its impact on antibiotic resistance in the environment. The objective of this review is to assess the state of knowledge regarding the impact of TCS on multidrug resistance in environmental settings, including engineered environments such as anaerobic digesters. Pure culture studies are reviewed in this paper to gain insight into the substantially smaller body of research surrounding the impacts of TCS on environmental microbial communities. Pure culture studies, mainly on pathogenic strains of bacteria, demonstrate that TCS is often associated with multidrug resistance. Research is lacking to quantify the current impacts of TCS discharge to the environment, but it is known that resistance to TCS and multidrug resistance can increase in environmental microbial communities exposed to TCS. Research plans are proposed to quantitatively define the conditions under which TCS selects for multidrug resistance in the environment.
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Affiliation(s)
| | - Patrick J. McNamara
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA
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23
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McNamara P, Krzmarzick M. Introductory Editorial: Water Microbiology. Microbiol Insights 2015; 8:33-5. [PMID: 27103820 PMCID: PMC4836622 DOI: 10.4137/mbi.s39866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Patrick McNamara
- Assistant Professor, Civil, Construction, and Environmental Engineering, Marquette University, Milwaukee, WI, USA
| | - Mark Krzmarzick
- Assistant Professor, Civil and Environmental Engineering, Oklahoma State University, Stillwater, OK, USA
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Krzmarzick MJ, Novak PJ. Removal of chlorinated organic compounds during wastewater treatment: achievements and limits. Appl Microbiol Biotechnol 2014; 98:6233-42. [DOI: 10.1007/s00253-014-5800-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 11/29/2022]
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Novel Firmicutes group implicated in the dechlorination of two chlorinated xanthones, analogues of natural organochlorines. Appl Environ Microbiol 2013; 80:1210-8. [PMID: 24296507 DOI: 10.1128/aem.03472-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Although the abundance and diversity of natural organochlorines are well established, much is still unknown about the degradation of these compounds. Triplicate microcosms were used to determine whether, and which, bacterial communities could dechlorinate two chlorinated xanthones (2,7-dichloroxanthone and 5,7-dichloro-1,3-dihydroxylxanthone), analogues of a diverse class of natural organochlorines. According to quantitative-PCR (qPCR) results, several known dechlorinating genera were either not present or not enriched during dechlorination of the xanthones. Denaturing gradient gel electrophoresis, however, indicated that several Firmicutes were enriched in the dechlorinating cultures compared to triplicate controls amended with nonchlorinated xanthones. One such group, herein referred to as the Gopher group, was further studied with a novel qPCR method that confirmed enrichment of Gopher group 16S rRNA genes in the dechlorinating cultures. The enrichment of the Gopher group was again tested with two new sets of triplicate microcosms. Enrichment was observed during chlorinated xanthone dechlorination in one set of these triplicate microcosms. In the other set, two microcosms showed clear enrichment while a third did not. The Gopher group is a previously unidentified group of Firmicutes, distinct from but related to the Dehalobacter and Desulfitobacterium genera; this group also contains clones from at least four unique cultures capable of dechlorinating anthropogenic organochlorines that have been previously described in the literature. This study suggests that natural chlorinated xanthones may be effective biostimulants to enhance the remediation of pollutants and highlights the idea that novel genera of dechlorinators likely exist and may be active in bioremediation and the natural cycling of chlorine.
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