1
|
Sun Y, Teng Y, Li R, Wang X, Zhao L. Microbiome resistance mediates stimulation of reduced graphene oxide to simultaneous abatement of 2,2',4,4',5-pentabromodiphenyl ether and 3,4-dichloroaniline in paddy soils. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133121. [PMID: 38056279 DOI: 10.1016/j.jhazmat.2023.133121] [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: 08/29/2023] [Revised: 10/12/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
Paddy soils near electrical and electronic waste recycling sites generally suffer from co-pollution of polybrominated diphenyl ethers and 3,4-dichloroaniline (3,4-DCA). This study tested the feasibility of reduced graphene oxide (rGO) to stimulate the simultaneous abatement of 2,2',4,4',5-pentabromodiphenyl ether (BDE99) and 3,4-DCA in percogenic paddy soil (PPS) and hydromorphic paddy soil (HPS). rGO improved the debromination extent of BDE99 and the transformation rate of 3,4-DCA in PPS, but did not affect their abatement in HPS. The inhibition of specific fermenters, acetogens, and methanogens after rGO addition contributed to BDE99 debromination by obligate organohalide-respiring bacteria (OHRB) in PPS, but relevant soil microbiomes (e.g., fermenters, acetogens, methanogens, and obligate OHRB) responded little to rGO in HPS. For 3,4-DCA, the enhanced activities of nitrogen-metabolic chloroaniline degraders by rGO increased its transformation rate in PPS, but was compensated by the decreased biotransformation from 3,4-DCA to 3,4-dichloroacetanilide after the addition of rGO to HPS. The discrepant stimulation of rGO between PPS and HPS was mediated by soil microbiome resistance. rGO has the application potential to stimulate the simultaneous abatement of polybrominated diphenyl ethers and chloroanilines in paddy soils with relatively low microbiome resistance.
Collapse
Affiliation(s)
- Yi Sun
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Teng
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Ran Li
- State Key Laboratory of Nutrient Use and Management, Key Laboratory of Wastes Matrix Utilization, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Xia Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ling Zhao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
2
|
Xiao Z, Jiang W, Chen D, Xu Y. Bioremediation of typical chlorinated hydrocarbons by microbial reductive dechlorination and its key players: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 202:110925. [PMID: 32800212 DOI: 10.1016/j.ecoenv.2020.110925] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/11/2020] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
Chlorinated hydrocarbon contamination in soils and groundwater has a severe negative impact on the human health. Microbial reductive dechlorination is a major degradation pathway of chlorinated hydrocarbon in anaerobic subsurface environments, has been extensively studied. Recent progress on the diversity of the reductive dechlorinators and the key enzymes of chlororespiration has been well reviewed. Here, we present a thorough overview of the studies related to bioremediation of chloroethenes and polychlorinated biphenyls based on enhanced in situ reductive dechlorination. The major part of this review is to provide an up-to-date summary of functional microorganisms which are either detected during in situ biostimulation or applied in bioaugmentation strategies. The applied biostimulants and corresponding reductive dechlorination products are also summarized and the future research needs are finally discussed.
Collapse
Affiliation(s)
- Zhixing Xiao
- College of Urban Construction, Nanjing Tech University, Nanjing, 211816, PR China
| | - Wei Jiang
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 210096, PR China
| | - Dan Chen
- College of Urban Construction, Nanjing Tech University, Nanjing, 211816, PR China
| | - Yan Xu
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, 210096, PR China.
| |
Collapse
|
3
|
Temme HR, Novak PJ. Diverse dechlorinators and dechlorination genes enriched through amendment of chlorinated natural organic matter fractions. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:595-605. [PMID: 31942582 DOI: 10.1039/c9em00499h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In uncontaminated environments, chlorinated natural organic matter (Cl-NOM) can act as an electron acceptor for organohalide-respiring bacteria. It is unknown, however, whether different types of Cl-NOM are preferentially dechlorinated or whether enrichment with Cl-NOM affects the ability of bacteria to dechlorinate contaminants. In this research NOM was extracted from sediment, fractionated based on hydrophobicity, and either amended to polychlorinated biphenyl-contaminated soil directly or chlorinated and then amended to soil. Amendments of the least hydrophobic Cl-NOM fraction were dechlorinated most rapidly, followed by the moderately hydrophobic Cl-NOM fraction. Soil that had been enriched on the moderately hydrophobic fraction of Cl-NOM was also capable of faster dechlorination of the contaminants trichloroethene and tetrachlorobenzene. Community analysis of the soil during enrichment showed that some known organohalide-respiring bacteria were present and may have played a role in dechlorination; nevertheless, many bacteria appeared to be enriched during both Cl-NOM and contaminant dechlorination. In addition, the quantities of two haloalkane dehalogenase genes increased during enrichment on Cl-NOM. These results show for the first time that Cl-NOM can prime contaminant dechlorination and also suggest that hydrolytic dechlorination processes were involved in both Cl-NOM and contaminant dechlorination.
Collapse
Affiliation(s)
- Hanna R Temme
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, USA.
| | | |
Collapse
|
4
|
Pimviriyakul P, Wongnate T, Tinikul R, Chaiyen P. Microbial degradation of halogenated aromatics: molecular mechanisms and enzymatic reactions. Microb Biotechnol 2020; 13:67-86. [PMID: 31565852 PMCID: PMC6922536 DOI: 10.1111/1751-7915.13488] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/01/2019] [Accepted: 09/03/2019] [Indexed: 12/12/2022] Open
Abstract
Halogenated aromatics are used widely in various industrial, agricultural and household applications. However, due to their stability, most of these compounds persist for a long time, leading to accumulation in the environment. Biological degradation of halogenated aromatics provides sustainable, low-cost and environmentally friendly technologies for removing these toxicants from the environment. This minireview discusses the molecular mechanisms of the enzymatic reactions for degrading halogenated aromatics which naturally occur in various microorganisms. In general, the biodegradation process (especially for aerobic degradation) can be divided into three main steps: upper, middle and lower metabolic pathways which successively convert the toxic halogenated aromatics to common metabolites in cells. The most difficult step in the degradation of halogenated aromatics is the dehalogenation step in the middle pathway. Although a variety of enzymes are involved in the degradation of halogenated aromatics, these various pathways all share the common feature of eventually generating metabolites for utilizing in the energy-producing metabolic pathways in cells. An in-depth understanding of how microbes employ various enzymes in biodegradation can lead to the development of new biotechnologies via enzyme/cell/metabolic engineering or synthetic biology for sustainable biodegradation processes.
Collapse
Affiliation(s)
- Panu Pimviriyakul
- Department of BiotechnologyFaculty of Engineering and Industrial TechnologySilpakorn UniversityNakhon Pathom73000Thailand
| | - Thanyaporn Wongnate
- School of Biomolecular Science and EngineeringVidyasirimedhi Institute of Science and Technology (VISTEC)Wangchan ValleyRayong21210Thailand
| | - Ruchanok Tinikul
- Department of Biochemistry and Center for Excellence in Protein and Enzyme TechnologyFaculty of ScienceMahidol UniversityBangkok10400Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and EngineeringVidyasirimedhi Institute of Science and Technology (VISTEC)Wangchan ValleyRayong21210Thailand
| |
Collapse
|
5
|
Chen C, He J. Strategy for the Rapid Dechlorination of Polychlorinated Biphenyls (PCBs) by Dehalococcoides mccartyi Strains. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13854-13862. [PMID: 30457846 DOI: 10.1021/acs.est.8b03198] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Anaerobic bacteria play critical roles in the environmental bioremediation of polychlorinated biphenyls (PCBs). However, in situ applications of PCB dechlorinating anaerobes have been largely impeded by difficulties in growing PCB dechlorinators to a high cell abundance in short time periods. Here, we report the accelerated onset of PCB dechlorination by pre-cultivating Dehalococcoides mccartyi strains on chloroethenes as alternative electron acceptors. The extensive dechlorination of Aroclor 1260 was achieved within 1 week by D. mccartyi CG4 pregrown on trichloroethene (TCE) or tetrachloroethene (PCE). Compared to control cultures fed solely with Aroclor 1260, the PCB dechlorination rate was up to 30 times greater in cultures pre-cultivated with chloroethenes. However, when CG4 was simultaneously exposed to multiple potential substrates (PCE, TCE, and PCBs), PCB dechlorination was not observed until PCE was completely depleted. The expression of the bifunctional PCE and PCBs reductive dehalogenase (RDase) gene pcbA4 was inhibited by the presence of both substrates. Furthermore, in the presence of >0.3 mM TCE (produced as an intermediate from PCE dechlorination), the PCB dechlorination rate was an order of magnitude lower than in cultures amended with Aroclor 1260 after the complete depletion of TCE. This reduced PCB dechlorination rate corresponded with a sharp decrease in pcbA4 transcripts in the presence of both TCE and PCBs. The utilization of chloroethenes and PCBs as substrates by CG4 was found to be largely sequential rather than concurrent, suggesting that PCE and TCE are preferred substrates for the RDase responsible for PCE, TCE, and PCB dechlorination.
Collapse
Affiliation(s)
- Chen Chen
- Department of Civil and Environmental Engineering , National University of Singapore , Singapore , 117576
| | - Jianzhong He
- Department of Civil and Environmental Engineering , National University of Singapore , Singapore , 117576
| |
Collapse
|
6
|
Puentes Jácome LA, Edwards EA. A switch of chlorinated substrate causes emergence of a previously undetected native Dehalobacter population in an established Dehalococcoides-dominated chloroethene-dechlorinating enrichment culture. FEMS Microbiol Ecol 2018; 93:4569067. [PMID: 29088371 DOI: 10.1093/femsec/fix141] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 10/26/2017] [Indexed: 01/08/2023] Open
Abstract
Chlorobenzenes are soil and groundwater pollutants of concern that can be reductively dehalogenated by organohalide-respiring bacteria from the genera Dehalococcoides and Dehalobacter. The bioaugmentation culture KB-1® harbours Dehalococcoides mccartyi spp. that reductively dehalogenate trichloroethene to ethene. It contains more than 30 reductive dehalogenase genes; some of them are highly similar to genes found in the chlorobenzene-respiring Dehalococcoides mccartyi strain CBDB1. We explored the chlorobenzene dehalogenation capability of the KB-1 enrichment culture using 1,2,4-trichlorobenzene (1,2,4-TCB). We achieved adaptation of KB-1 to 1,2,4-TCB that is dehalogenated to a mixture of dichlorobenzenes, and subsequently to monochlorobenzene and benzene. Surprisingly, a native Dehalobacter population, and not a Dehalococcoides population, couples the dechlorination of 1,2,4-TCB to growth achieving an average yield of 1.1 ± 0.6 × 1013 cells per mole of Cl- released. Interestingly, the dechlorination of 1,2,4-TCB occurs alongside the complete dechlorination of trichloroethene to ethene in cultures fed both electron acceptors. Dehalobacter was not previously identified as a major player in KB-1, but its ecological niche was favoured by the introduction of 1,2,4-TCB. Based on 16S rRNA phylogeny, Dehalobacter populations seem to cluster into specialised clades, and are likely undergoing substrate specialisation as a strategy to reduce competition for electron acceptors.
Collapse
Affiliation(s)
- Luz A Puentes Jácome
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 1A1, Canada
| |
Collapse
|
7
|
Ma Y, Zhao Y, Wang Y, Li X, Sun F, Corvini PFX, Ji R. Effects of Cu 2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp. strain CDT. J Environ Sci (China) 2017; 62:60-67. [PMID: 29289293 DOI: 10.1016/j.jes.2017.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
Soil contamination with tetrabromobisphenol A (TBBPA) has caused great concerns; however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with 14C-labeled TBBPA for 87 days in the absence and presence of Cu2+ and humic acids (HA). TBBPA was degraded to organic-solvent extractable (59.4%±2.2%) and non-extractable (25.1%±1.3%) metabolites, mineralized to CO2 (4.8%±0.8%), and assimilated into cells (10.6%±0.9%) at the end of incubation. When Cu2+ was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu2+ to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1%±3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu2+ and HA were both present, Cu2+ significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu2+ and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity.
Collapse
Affiliation(s)
- Yini Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Yingying Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Yongfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Xiangzhen Li
- Key Laboratory of Environmental and Applied Microbiology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Feifei Sun
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Phillippe Francois-Xavier Corvini
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China; Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, Muttenz CH-4132, Switzerland
| | - Rong Ji
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
| |
Collapse
|
8
|
Xiong J, Li G, An T. The microbial degradation of 2,4,6-tribromophenol (TBP) in water/sediments interface: Investigating bioaugmentation using Bacillus sp. GZT. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:573-580. [PMID: 27613672 DOI: 10.1016/j.scitotenv.2016.09.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 06/06/2023]
Abstract
The substance 2,4,6-Tribromophenol (TBP) is used as a flame retardant in electronic and electric devices, and is a replacement for pentachlorophenol in wood preservation. TBP is a contaminant in different environmental matrices, at levels where treatment is required. This study examined the relationship between the bioaugmention of TBP degradation and the evolution of the microbial community in river water/sediment microcosms. When compared with unamended controls, bioaugmentation with Bacillus sp. GZT effectively enhanced TBP biodegradation, with approximately 40.7% of the TBP removal after a 7-week incubation period, without a lag phase (p<0.01). Amendments with 2-bromophenol, 2,6-dibromophenol, and 2,4-dibromophenol did not promote TBP biodegradation in river water/sediments (p>0.05). However, TBP biodegradation was enhanced by adding other additives, including NaCl, humic acid, sodium lactate, and sodium propionate alone, especially glucose and yeast extract. A metagenomics analysis of the total 16S rRNA genes from the treatment system with bioaugmentation showed that four microbial phyla were dominant: Proteobacteria (52.08-66.22%), Actinobacteria (20.03-5.47%), Bacteroidetes (6.68-13.68%), and Firmicutes (4.53-20.83%). This study highlights the possible benefits using bioaugmentation with GZT to remediate TBP-polluted water and sediments.
Collapse
Affiliation(s)
- Jukun Xiong
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guiying Li
- Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Taicheng An
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| |
Collapse
|
9
|
Li G, Xiong J, Wong PK, An T. Enhancing tetrabromobisphenol A biodegradation in river sediment microcosms and understanding the corresponding microbial community. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 208:796-802. [PMID: 26602791 DOI: 10.1016/j.envpol.2015.11.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/30/2015] [Accepted: 11/01/2015] [Indexed: 06/05/2023]
Abstract
In situ remediation of contaminated sediment using microbes is a promising environmental treatment method. This study used bioaugmentation to investigate the biodegradation of tetrabromobisphenol A (TBBPA) in sediment microcosms collected from an electronic-waste recycling site. Treatments included adding possible biodegradation intermediates of TBBPA, including 2,4-dibromophenol (2,4-DBP), 2,4,6-tribromophenol (TBP), and bisphenol A (BPA) as co-substrates. Bioaugmentation was done with Ochrobactrum sp. T (TBBPA-degrader) and a mixed culture of Ochrobactrum sp. T, Bacillus sp. GZT (TBP-degrader) and Bacillus sp. GZB (BPA-degrader). Results showed that bioaugmentation with Ochrobactrum sp. T significantly improved TBBPA degradation efficiencies in sediment microcosms (P < 0.01); aerobic conditions increased the microbes' degradation activities. Co-substrates 2,4-DBP, TBP and BPA inhibited biodegradation of TBBPA. A metagenomic analysis of total 16S rRNA genes from the treated sediment microcosms showed that the following dominant genera: Ochrobactrum, Parasegetibacter, Thermithiobacillus, Phenylobacterium and Sphingomonas. The genus level of Ochrobactrum increased with increased degradation time, within 10-week of incubation. Microbes from genus Ochrobactrum are mainly linked to enhance the TBBPA biodegradation.
Collapse
Affiliation(s)
- Guiying Li
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Jukun Xiong
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Po Keung Wong
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong Special Administrative Region
| | - Taicheng An
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
| |
Collapse
|
10
|
Hughes AS, VanBriesen JM, Small MJ. Impacts of PCB analytical interpretation uncertainties on dechlorination assessment and remedial decisions. CHEMOSPHERE 2015; 133:61-67. [PMID: 25935496 DOI: 10.1016/j.chemosphere.2015.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 03/16/2015] [Accepted: 04/05/2015] [Indexed: 06/04/2023]
Abstract
Laboratory analyses of polychlorinated biphenyls (PCBs) often do not quantitate the 209 individual PCB congeners, thereby requiring analyst interpretation to determine individual congener concentrations. Error introduced during this interpretation is subsequently propagated to calculated surrogate variables, such as the number of chlorines per biphenyl (CPB), and the molar dechlorination product ratio (MDPR), which are used to assess the extent of dechlorination and inform remedial decisions. The present work applies a Monte Carlo (MC) analysis to assess current methods for quantitating co-eluting congeners and the errors that could occur in individual congeners and derived CPB and MDPR estimates. Synthetic chromatograms, which were created using two alternative methods (random assignment and assignment based on relative proportions in Aroclors) for assigning mass to co-eluting congeners, were compared to their fully-quantitated counterparts. The percent error introduced in total PCB (∑PCB) concentration ranges from approximately -60% to +50%. Similarly, the errors associated with CPB and MDPR estimates range from approximately -20% to +20% and -120% to +30%, respectively. Uncertainties introduced during congener analysis and propagated to surrogate variables can thus be substantial, and should be considered in assessments of the extent of dechlorination and associated remedial decisions.
Collapse
Affiliation(s)
- Amanda S Hughes
- Geosyntec Consultants, 134 North LaSalle Street, Suite 300, Chicago, IL 60602, United States
| | - Jeanne M VanBriesen
- Department of Civil & Environmental Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, United States.
| | - Mitchell J Small
- Department of Civil & Environmental Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, United States; Department of Engineering & Public Policy, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, United States
| |
Collapse
|
11
|
Sowers KR, May HD. In situ treatment of PCBs by anaerobic microbial dechlorination in aquatic sediment: are we there yet? Curr Opin Biotechnol 2013; 24:482-8. [PMID: 23102490 PMCID: PMC3572274 DOI: 10.1016/j.copbio.2012.10.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 09/14/2012] [Accepted: 10/03/2012] [Indexed: 11/29/2022]
Abstract
The remediation of polychlorinated biphenyls (PCBs) in soils and sediments remains a particularly difficult problem to solve. The possibility of in situ degradation by microorganisms has been pursued for many years since this approach has the potential to provide a cost-effective and environmentally sustainable alternative to dredging for treatment of PCB impacted sites. Being hydrophobic, PCBs partition into organic material and accumulate in anoxic environments well poised to support anaerobic dechlorination of highly chlorinated congeners; products of which are susceptible to complete aerobic degradation. Laboratory research over the past 25 years is now leading to new microbial technologies that could soon be tested for treatment of PCB impacted sediments in the field.
Collapse
Affiliation(s)
- Kevin R Sowers
- Department of Marine Biotechnology, University of Maryland Baltimore County and Institute of Marine & Environmental Technology, University of Maryland, Baltimore, MD, USA
| | | |
Collapse
|
12
|
Rodenburg LA, Du S, Fennell DE, Cavallo GJ. Evidence for widespread dechlorination of polychlorinated biphenyls in groundwater, landfills, and wastewater collection systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:7534-7540. [PMID: 20828204 DOI: 10.1021/es1019564] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
One of the few pathways for environmental transformation of polychlorinated biphenyls (PCBs) is microbial dechlorination under anaerobic conditions, which is reported to occur in contaminated sediments of rivers, lakes and harbors. The goal of this work was to determine whether PCB dechlorination occurs in built waste treatment environments. We analyzed a large database on PCB congener concentrations in effluents and some influents of facilities in the Delaware River Basin. Positive matrix factorization was used to identify the sources of PCBs and to look for evidence of dechlorination. Seven factors were resolved from the data set of 89 congeners in 645 samples. Two of the resolved factors represented dechlorination signals. One of these was dominated by PCBs 4 and 19 and represents an advanced stage of dechlorination of Aroclors to di- and trichlorinated congeners. This dechlorination signal was most prevalent in effluents from sites with contaminated groundwater and from wastewater treatment plants (WWTPs) that serve combined sewers or treat landfill leachate. The other dechlorination signal appeared to represent an intermediate stage of dechlorination, because it was dominated by two coeluting groups of tetrachlorinated congeners: PCBs 44 + 47 + 65 and 45 + 51. This partial dechlorination signal was most prevalent in the 40 WWTPs with separate (sanitary) sewer systems, where it often comprised more than 20% of the PCBs in the effluents. Both dechlorination signals were present in WWTP influents, but were not observed in stormwater runoff, suggesting that dechlorination occurs in sewers. This work represents the first convincing evidence of PCB dechlorination occurring outside of contaminated aquatic sediments or anaerobic digesters. The results suggest that PCBs are dechlorinated by anaerobic bacteria in sewers, landfills, and contaminated groundwater. These two dechlorination signals comprise about 19% of the total loads of PCBs to the Delaware River from the sampled dischargers.
Collapse
Affiliation(s)
- Lisa A Rodenburg
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, USA.
| | | | | | | |
Collapse
|
13
|
Krumins V, Park JW, Son EK, Rodenburg LA, Kerkhof LJ, Häggblom MM, Fennell DE. PCB dechlorination enhancement in Anacostia River sediment microcosms. WATER RESEARCH 2009; 43:4549-4558. [PMID: 19744693 DOI: 10.1016/j.watres.2009.08.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 07/28/2009] [Accepted: 08/03/2009] [Indexed: 05/28/2023]
Abstract
In situ treatment of PCB contaminated sediments via microbial dechlorination is a promising alternative to dredging, which may be reserved for only the most contaminated areas. Reductive dechlorination of low levels of weathered PCB mixtures typical of urban environments may occur at slow rates. Here, we report that biostimulation and bioaugmentation enhanced dechlorination of low concentration (2.1 mg PCBs/kg dry weight) historical PCBs in microcosms prepared with Anacostia River, Washington, DC, sediment. Treatments included electron donors butyrate, lactate, propionate and acetate (1 mM each); alternate halogenated electron acceptors (haloprimers) tetrachlorobenzene (TeCB, 25 microM), pentachloronitrobenzene (PCNB, 25 microM), or 2,3,4,5,6-PCB (PCB116, 2.0 microM); and/or bioaugmentation with a culture containing Dehalococcoides ethenogenes strain 195 (3 x 10(6)cells/mL). Dechlorination rates were enhanced in microcosms receiving bioaugmentation, PCNB and PCNB plus bioaugmentation, compared to other treatments. Microcosm subcultures generated after 415 days and spiked with PCB116 showed sustained capacity for dechlorination of PCB116 in PCNB, PCNB plus bioaugmentation, and TeCB treatments, relative to other treatments. Analysis of Chloroflexi 16S rRNA genes showed that TeCB and PCNB increased native Dehalococcoides spp. from the Pinellas subgroup; however this increase was correlated to enhanced dechlorination of low concentration weathered PCBs only in PCNB-amended microcosms. D. ethenogenes strain 195 was detected only in bioaugmented microcosms and decreased over 281 days. Bioaugmentation with D. ethenogenes strain 195 increased PCB dechlorination rates initially, but enhanced capacity for dechlorination of a model congener, PCB116, after 415 days occurred only in microcosms with enhanced native Dehalococcoides spp.
Collapse
Affiliation(s)
- Valdis Krumins
- Department of Environmental Sciences, Rutgers-The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, USA
| | | | | | | | | | | | | |
Collapse
|
14
|
Field JA, Sierra-Alvarez R. Microbial transformation and degradation of polychlorinated biphenyls. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2008; 155:1-12. [PMID: 18035460 DOI: 10.1016/j.envpol.2007.10.016] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Accepted: 10/14/2007] [Indexed: 05/25/2023]
Abstract
This paper reviews the potential of microorganisms to transform polychlorinated biphenyls (PCBs). In anaerobic environments, higher chlorinated biphenyls can undergo reductive dehalogenation. Meta- and para-chlorines in PCB congeners are more susceptible to dechlorination than ortho-chlorines. Anaerobes catalyzing PCB dechlorination have not been isolated in pure culture but there is strong evidence from enrichment cultures that some Dehalococcoides spp. and other microorganisms within the Chloroflexi phylum can grow by linking the oxidation of H(2) to the reductive dechlorination of PCBs. Lower chlorinated biphenyls can be co-metabolized aerobically. Some aerobes can also grow by utilizing PCB congeners containing only one or two chlorines as sole carbon/energy source. An example is the growth of Burkholderia cepacia by transformation of 4-chlorobiphenyl to chlorobenzoates. The latter compounds are susceptible to aerobic mineralization. Higher chlorinated biphenyls therefore are potentially fully biodegradable in a sequence of reductive dechlorination followed by aerobic mineralization of the lower chlorinated products.
Collapse
Affiliation(s)
- Jim A Field
- Department of Chemical and Environmental Engineering, University of Arizona, PO Box 210011, Tucson, AZ 85721, USA.
| | | |
Collapse
|
15
|
Bunge M, Wagner A, Fischer M, Andreesen JR, Lechner U. Enrichment of a dioxin-dehalogenating Dehalococcoides species in two-liquid phase cultures. Environ Microbiol 2008; 10:2670-83. [DOI: 10.1111/j.1462-2920.2008.01688.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
16
|
Fagervold SK, May HD, Sowers KR. Microbial reductive dechlorination of aroclor 1260 in Baltimore harbor sediment microcosms is catalyzed by three phylotypes within the phylum Chloroflexi. Appl Environ Microbiol 2007; 73:3009-18. [PMID: 17351091 PMCID: PMC1892865 DOI: 10.1128/aem.02958-06] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The specific dechlorination pathways for Aroclor 1260 were determined in Baltimore Harbor sediment microcosms developed with the 11 most predominant congeners from this commercial mixture and their resulting dechlorination intermediates. Most of the polychlorinated biphenyl (PCB) congeners were dechlorinated in the meta position, and the major products were tetrachlorobiphenyls with unflanked chlorines. Using PCR primers specific for the 16S rRNA genes of known PCB-dehalogenating bacteria, we detected three phylotypes within the microbial community that had the capability to dechlorinate PCB congeners present in Aroclor 1260 and identified their selective activities. Phylotype DEH10, which has a high level of sequence identity to Dehalococcoides spp., removed the double-flanked chlorine in 234-substituted congeners and exhibited a preference for para-flanked meta-chlorines when no double-flanked chlorines were available. Phylotype SF1 had similarity to the o-17/DF-1 group of PCB-dechlorinating bacteria. Phylotype SF1 dechlorinated all of the 2345-substituted congeners, mostly in the double-flanked meta position and 2356-, 236-, and 235-substituted congeners in the ortho-flanked meta position, with a few exceptions. A phylotype with 100% sequence identity to PCB-dechlorinating bacterium o-17 was responsible for an ortho and a double-flanked meta dechlorination reaction. Most of the dechlorination pathways supported the growth of all three phylotypes based on competitive PCR enumeration assays, which indicates that PCB-impacted environments have the potential to sustain populations of these PCB-dechlorinating microorganisms. The results demonstrate that the variation in dechlorination patterns of congener mixtures typically observed at different PCB impacted sites can potentially be mediated by the synergistic activities of relatively few dechlorinating species.
Collapse
Affiliation(s)
- Sonja K Fagervold
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, 701 E. Pratt St., Baltimore, MD 21202, USA
| | | | | |
Collapse
|
17
|
Häggblom MM, Ahn YB, Fennell DE, Kerkhof LJ, Rhee SK. Anaerobic Dehalogenation of Organohalide Contaminants in the Marine Environment. ADVANCES IN APPLIED MICROBIOLOGY 2003; 53:61-84. [PMID: 14696316 DOI: 10.1016/s0065-2164(03)53002-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Microbially mediated dehalogenation processes contribute to the global cycling of both biogenic and anthropogenic halogenated organic compounds. Detailed information on biodegradation mechanisms for a variety of organohalides and on the microorganisms mediating these processes has greatly increased our understanding of the cycling and fate of these unique and widespread compounds in our environment. The marine environment appears to be a particularly rich source of dehalogenating microorganisms. It is well established by laboratory and field studies that anaerobic dehalogenation of sediment contaminants, such as PCBs, pesticides, and dioxins, occurs intrinsically and can be enhanced via various methods. Specific dehalogenating bacterial populations can be enriched on various organohalides. Biodehalogenation processes are likely to be significantly affected by the prevailing terminal electron-accepting condition, and thus, biotransformation of organohalide contaminants in marine and estuarine environments will vary as a function of the redox conditions within the sediment profile. Fundamental knowledge of the activities and interactions of dehalogenating microorganisms is providing a strong basis for development of new bioremediation technologies for removal of harmful halogenated compounds from our environment.
Collapse
Affiliation(s)
- Max M Häggblom
- Department of Biochemistry and Microbiology & Biotechnology Center for Agriculture and the Environment, State University of New Jersey, New Brunswick, New Jersey 08901, USA
| | | | | | | | | |
Collapse
|