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Chen J, Xu F, Yang K, Chen C, Wan J, Shen C. The amendment of Organic matters enhances the anaerobic dechlorination of Polychlorinated Biphenyls in Paddy Soil. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 109:393-400. [PMID: 35687131 DOI: 10.1007/s00128-022-03563-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
The toxicity of high-chlorinated polychlorinated biphenyls (PCBs) can be efficiently reduced through anaerobic dechlorination. However, this approach suffers a lot in face of in situ microbial remediations, like a shortage of biomass. In this study, we showed that the amendment of organic matters could help microbiota in paddy soil with anaerobic dechlorination and greatly shortened the lag period. The presence of organic matters offered a better environment for dechlorinating bacteria. They provided not only a more strictly anaerobic milieu but also copious carbon sources. By using high-throughput 16S rRNA gene sequencing, genera Dehalobacter, Dehalobacterium, and Desulfitobacterium capable of dechlorination were identified in enriched cultures. Taken together, this study proved that extra organic matters can promote anaerobic dechlorination in paddy soil slurry microcosm systems, which provides new insights into the bioremediation of PCB-contaminated soils.
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Affiliation(s)
- Jingwen Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Fengjun Xu
- Department of Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Kai Yang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Chen Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, 310058, Hangzhou, China
- Department of Civil and Environmental Engineering, National University of Singapore, Queenstown, Singapore
| | - Jixing Wan
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, 310058, Hangzhou, China.
- Zhejiang Provincial Key Laboratory for Water Pollution Control and Environmental Safety, 310058, Hangzhou, China.
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Passatore L, Rossetti S, Juwarkar AA, Massacci A. Phytoremediation and bioremediation of polychlorinated biphenyls (PCBs): state of knowledge and research perspectives. JOURNAL OF HAZARDOUS MATERIALS 2014; 278:189-202. [PMID: 24976127 DOI: 10.1016/j.jhazmat.2014.05.051] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/15/2014] [Accepted: 05/16/2014] [Indexed: 05/20/2023]
Abstract
This review summarizes the bioremediation and phytoremediation technologies proposed so far to detoxify PCB-contaminated sites. A critical analysis about the potential and limits of the PCB pollution treatment strategies by means of plants, fungi and bacteria are elucidated, including the new insights emerged from recent studies on the rhizosphere potential and on the implementation of simultaneous aerobic and anaerobic biodegradation processes. The review describes the biodegradation and phytoremediation processes and elaborates on the environmental variables affecting contaminant degradation rates, summarizing the amendments recommended to enhance PCB degradation. Additionally, issues connected with PCB toxicology, actual field remediation strategies and economical evaluation are discussed.
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Affiliation(s)
- Laura Passatore
- Institute of Agro-environment and Forest Biology (IBAF), National Research Council (CNR), Via Salaria Km 29.300, 00015 Monterotondo (Rome), Italy; Department for Innovation in Biological, Agro-Food and Forest Systems (DIBAF), University of Tuscia, Via S. Camillo de Lellis snc, 01100 Viterbo, Italy
| | - Simona Rossetti
- Water Research Institute (IRSA), National Research Council (CNR), Via Salaria Km 29.300, 00015 Monterotondo (Rome), Italy
| | - Asha A Juwarkar
- Environmental Biotechnology Division, National Environmental Engineering Research Institute (NEERI), Nehru Marg, Nagpur 440 020, India
| | - Angelo Massacci
- Institute of Agro-environment and Forest Biology (IBAF), National Research Council (CNR), Via Salaria Km 29.300, 00015 Monterotondo (Rome), Italy.
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Chen C, Yu C, Shen C, Tang X, Qin Z, Yang K, Hashmi MZ, Huang R, Shi H. Paddy field--a natural sequential anaerobic-aerobic bioreactor for polychlorinated biphenyls transformation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 190:43-50. [PMID: 24721413 DOI: 10.1016/j.envpol.2014.03.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/11/2014] [Accepted: 03/19/2014] [Indexed: 06/03/2023]
Abstract
The environmental pollution and health risks caused by the improper disposal of electric and electronic waste (e-waste) have become urgent issues for the developing countries. One of the typical pollutants, polychlorinated biphenyls (PCBs), is commonly found in farmland in Taizhou, a major hotspot of e-waste recycling in China. This study investigated the amount of PCB residue in local farmlands. Biotransformation of PCBs was further studied under different water management conditions in paddy field with or without rice cultivation, with a special focus on the alternating flooded and drying processes. It was found that paddy field improved the attenuation of PCBs, especially for highly chlorinated congeners. In the microcosm experiment, 40% or more of the initial total PCBs was removed after sequential flood-drying treatments, compared to less than 10% in the sterilized control and 20% in the constant-drying system. Variation in the quantity of PCBs degrading and dechlorinating bacterial groups were closely related to the alteration of anaerobic-aerobic conditions. These results suggested that alternating anoxic-oxic environment in paddy field led to the sequential aerobic-anaerobic transformation of PCBs, which provided a favorable environment for natural PCB attenuation.
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Affiliation(s)
- Chen Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chunna Yu
- Center for Biomedicine and Health, Hangzhou Normal University, Hangzhou 311121, China
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xianjin Tang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Zhihui Qin
- The Academy of Water Science and Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Kai Yang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Muhammad Zaffar Hashmi
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ronglang Huang
- The Academy of Water Science and Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Huixiang Shi
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; The Academy of Water Science and Environmental Engineering, Zhejiang University, Hangzhou 310058, China
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4
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Winchell LJ, Novak PJ. Enhancing polychlorinated biphenyl dechlorination in fresh water sediment with biostimulation and bioaugmentation. CHEMOSPHERE 2008; 71:176-182. [PMID: 18037157 DOI: 10.1016/j.chemosphere.2007.10.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 10/10/2007] [Accepted: 10/11/2007] [Indexed: 05/25/2023]
Abstract
Polychlorinated biphenyls (PCBs) are toxic compounds ubiquitously distributed in ecosystems. Microbial attenuation of these contaminants is a potential means of remediation. Two promising microbial PCB remediation technologies, biostimulation and bioaugmentation, were investigated in different sediments. Biostimulation experiments in which electron donor was supplied (H2 via elemental iron, Fe(0)) resulted in only a marginal improvement in the dechlorination of amended 2,3,4,5-tetrachlorobiphenyl (2,3,4,5-CB), likely because of an inadequate population of indigenous H2-utilizing dechlorinators. Extensive dechlorination was observed, however, after bioaugmenting microcosms with a PCB-dechlorinating enrichment culture. Dechlorination of 2,3,4,5-CB began prior to the 20th day of incubation and proceeded to 2-chlorobiphenyl. This extensive dechlorination activity was maintained in both sediments over 70d at 10 and 25 degrees C. This research demonstrates that although past studies of biostimulation were promising, a great deal must be known about the PCB-dechlorinating organisms present before successful biostimulation is expected. Bioaugmentation, however, appears to be a promising PCB remediation strategy and should be further pursued.
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Affiliation(s)
- Lloyd J Winchell
- The Department of Civil Engineering, University of Minnesota, 122 Civil Engineering Building, 500 Pillsbury Drive S.E., Minneapolis, MN 55455-0220, United States
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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.
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Affiliation(s)
- Sonja K Fagervold
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, 701 E. Pratt St., Baltimore, MD 21202, USA
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Yan T, LaPara TM, Novak PJ. The effect of varying levels of sodium bicarbonate on polychlorinated biphenyl dechlorination in Hudson River sediment cultures. Environ Microbiol 2006; 8:1288-98. [PMID: 16817937 PMCID: PMC1945130 DOI: 10.1111/j.1462-2920.2006.01037.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The addition of different concentrations of sodium bicarbonate had a profound effect on 2,3,4,5-chlorobiphenyl (2,3,4,5-CB) dechlorination in Hudson River sediment cultures. The most extensive dechlorination was observed in cultures to which 100 mg l(-1) bicarbonate was added. Cultures amended with 1000 mg l(-1) bicarbonate had the least extensive dechlorination, with 2,4-CB and 2,5-CB as predominant end-products. A significant loss of total chlorinated biphenyl mass was observed in cultures to which < or = 500 mg l(-1) bicarbonate was added, suggesting that degradation beyond chlorinated biphenyls occurred. The dynamics of acetate formation were different among the treatments, with high acetate concentrations detected throughout the 303-day experiment in cultures to which 1000 mg l(-1) bicarbonate had been added. Sodium bicarbonate addition also had a significant impact on bacterial community structure as detected by polymerase chain reaction-denaturant gradient gel electrophoresis (PCR-DGGE) of 16S rRNA gene fragments. Three putative polychlorinated biphenyl (PCB) dechlorinators were identified; one Dehalococcoides-like population was detected in all enrichment cultures, whereas two Dehalobacter-like populations were only detected in the enrichment cultures with the most extensive dechlorination. These results suggest that the availability of bicarbonate, and potentially sodium, may affect PCB dechlorination in Hudson River sediment and thus need to be taken into consideration when assessing the fate of PCBs or implementing bioremediation.
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Affiliation(s)
| | | | - Paige J. Novak
- *For correspondence. E-mail ; Tel. (+1) 612 626 9846; Fax (+1) 612 626 7750
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Rysavy JP, Yan T, Novak PJ. Enrichment of anaerobic polychlorinated biphenyl dechlorinators from sediment with iron as a hydrogen source. WATER RESEARCH 2005; 39:569-578. [PMID: 15707629 DOI: 10.1016/j.watres.2004.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 11/05/2004] [Accepted: 11/22/2004] [Indexed: 05/24/2023]
Abstract
Little is known about anaerobic polychlorinated biphenyl (PCB) dechlorination, although it is believed that some microorganisms are capable of respiring PCBs, gaining energy for growth from PCB dechlorination. If this is the case, the amendment of appropriate electron donors to contaminated sediment should stimulate dechlorination. The effect of elemental iron (Fe0) addition, an easily amended electron donor, on the microbial dechlorination of the PCB congeners 3,4,5-trichlorobiphenyl (3,4,5-CB) and 2,2',3,4,4',5,5'-heptachlorobiphenyl (2,2',3,4,4',5,5'-CB) was investigated in microcosms containing estuarine sediment from Baltimore Harbor. Results showed that the addition of 0.1 g Fe0/g sediment reduced the lag time for removal of doubly flanked para chlorines by approximately 100 days. Because Fe0 is a source of cathodic hydrogen (H2), the effect of direct H2 addition to sediment microcosms was also tested. The addition of 0.001 atm H2 in the headspace generated the same dechlorination activity and reduction in lag time as the addition of 0.1g Fe0/g. Higher concentrations of Fe0 or H2 increased the lag prior to dechlorination. Additional results showed that an alkaline pH (> or = 7.5), high [Fe2+] (3.3 g/L), or HS- (0.1 mg/L total sulfide) inhibited dechlorination. Elevated concentrations of Fe2+, OH-, and HS- are products of Fe0 oxidation or increased microbial activity (methanogenesis, homoacetogenesis, and sulfate reduction), both of which would result from the amendment of large quantities of Fe0 or H2 to sediment. This research shows that not only can PCB dechlorination be stimulated through the addition of electron donor, but implies that the dechlorinators are enriched by the continuous addition of low concentrations of H2, similar to other known dechlorinators, such as the dehalorespirer Dehalococcoides ethenogenes. These results suggest that the direct addition of controlled amounts of Fe0 to sediments may be an effective remediation tool to reduce the lag period prior to dechlorination at PCB-impacted sites. They also suggest that PCB dechlorinators may be enriched using techniques similar to those used with known dehalorespirers.
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Affiliation(s)
- Jason P Rysavy
- The Department of Civil Engineering, University of Minnesota, 122 Civil Engineering Building, 500 Pillsbury Drive S.E., Minneapolis, MN 55455-0220, USA
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Nollet H, Van de Putte I, Raskin L, Verstraete W. Carbon/electron source dependence of polychlorinated biphenyl dechlorination pathways for anaerobic granules. CHEMOSPHERE 2005; 58:299-310. [PMID: 15581933 DOI: 10.1016/j.chemosphere.2004.07.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2003] [Revised: 06/14/2004] [Accepted: 07/13/2004] [Indexed: 05/24/2023]
Abstract
The effect of acclimating anaerobic granules from commercial bioreactors with different carbon/electron sources on their ability to reductively dechlorinate a tri-(2,3,4-CB) and heptachlorobiphenyl (2,2',3,3',4,5,6-CB) was studied. The anaerobic granules were first grown in upflow anaerobic sludge blanket (UASB) reactors fed with two different mixtures of carbon/electron sources, i.e., propionate/butyrate/methanol and formate/methanol. Differences in dechlorination patterns for 2,2',3,3',4,5,6-CB were observed in batch experiments inoculated with granules from these two sets of UASB reactors. Variation of the carbon/electron source, during the dechlorination process, had no effect on the dechlorination pathway, but the extents and rates of dechlorination were highest for ethanol and formate and lowest for pyruvate fed batches. Pre-acclimation of different anaerobic sludges to polychlorinated biphenyls (PCBs) shortened the lag period, but did not influence the PCB dechlorination pathway. This is the first time that similar acclimation conditions for several anaerobic microbial communities prior to inoculation were reported to yield similar substrate specificities for the reductive dechlorination of specific PCB congeners. This research demonstrates a successful strategy for the development of biocatalysts to serve as the inoculum of partially decontaminated sites in order to provide microorganisms with specificities complementary to those of naturally occurring dechlorinators.
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Affiliation(s)
- Hendrik Nollet
- Laboratory of Microbial Ecology and Technology, Faculty of Agricultural and Applied Biological Sciences, Ghent University, Coupure Links 653, Ghent 9000, Belgium
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Lee W, Batchelor B. Reductive capacity of natural reductants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:535-541. [PMID: 12630469 DOI: 10.1021/es025830m] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Reductive capacities of soil minerals and soil for Cr(VI) and chlorinated ethylenes were measured and characterized to provide basic knowledge for in-situ and ex-situ treatment using these natural reductants. The reductive capacities of iron-bearing sulfide (pyrite), hydroxide (green rust; GR(SO4)), and oxide (magnetite) minerals for Cr(VI) and tetrachloroethylene (PCE) were 1-3 orders of magnitude greater than those of iron-bearing phyllosilicates (biotite, vermiculite, and montmorillonite). The reductive capacities of surface soil collected from the plains of central Texas were similar and slightly greater than those of iron-bearing phyllosilicates. The reductive capacity of iron-bearing soil minerals for Cr(VI) was roughly 3-16 times greater than that for PCE, implying that Cr(VI) is more susceptible to being reduced by soil minerals than is PCE. GR(SO4) has the greatest reductive capacity for both Cr(VI) and PCE followed by magnetite, pyrite, biotite, montmorillonite, and vermiculite. This order was the same for both target compounds, which indicates that the relative reductive capacities of soil minerals are consistent. The reductive capacities of pyrite and GR(SO4) for chlorinated ethylenes decreased in the order: trichloroethylene (TCE) > PCE > cis-dichloroethylene (c-DCE) > vinyl chloride (VC). Fe(II) content in soil minerals was directly proportional to the reductive capacity of soil minerals for Cr(VI) and PCE, suggesting that Fe(II) content is an important factor that significantly affects reductive transformations of target contaminants in natural systems.
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Affiliation(s)
- Woojin Lee
- Environmental Science Research Center, School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, USA.
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Cutter LA, Watts JE, Sowers KR, May HD. Identification of a microorganism that links its growth to the reductive dechlorination of 2,3,5,6-chlorobiphenyl. Environ Microbiol 2001; 3:699-709. [PMID: 11846760 DOI: 10.1046/j.1462-2920.2001.00246.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Anaerobic bacteria reductively dechlorinate polychlorinated biphenyls (PCBs) in aquatic sediments, but these microorganisms remain uncultured and, until now, unidentified. Through denaturing gradient gel electrophoresis (DGGE) of 16S rDNA from a highly enriched ortho-PCB dechlorinating culture, the growth of a single microorganism was shown to be dependent upon the presence and dechlorination of 2,3,5,6-tetrachlorobiphenyl. This is the first identification of a microorganism that catalyses the reductive dechlorination of a PCB. The organism, bacterium o-17, has high sequence similarity with the green non-sulphur bacteria and with a group that includes Dehalococcoides ethenogenes. Bacterium o-17 required acetate for dechlorination and growth. H2:CO2 (80:20 at 101 kPa) did not support dechlorination or growth of the dechlorinator. Archaeal 16S rDNA was not detected in actively dechlorinating bromoethanesulphonate-treated non-methanogenic cultures, which indicated that methanogenic Archaea were not required for dechlorination. The consistent association with dechlorinating activity combined with high similarity to other known dechlorinating microorganisms indicates that bacterium o-17 catalyses the reductive ortho-dechlorination of 2,3,5,6-tetrachlorobiphenyl.
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Affiliation(s)
- L A Cutter
- Department of Microbiology and Immunology, Marine Biomedicine and Envionmental Sciences Program, Medical University of South Carolina, Charleston, SC, USA
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Abstract
Under anaerobic conditions, microbial reductive dechlorination of polychlorinated biphenyls (PCBs) occurs in soils and aquatic sediments. In contrast to dechlorination of supplemented single congeners for which frequently ortho dechlorination has been observed, reductive dechlorination mainly attacks meta and/or para chlorines of PCB mixtures in contaminated sediments, although in a few instances ortho dechlorination of PCBs has been observed. Different microorganisms appear to be responsible for different dechlorination activities and the occurrence of various dehalogenation routes. No axenic cultures of an anaerobic microorganism have been obtained so far. Most probable number determinations indicate that the addition of PCB congeners, as potential electron acceptors, stimulates the growth of PCB-dechlorinating microorganisms. A few PCB-dechlorinating enrichment cultures have been obtained and partially characterized. Temperature, pH, availability of naturally occurring or of supplemented carbon sources, and the presence or absence of H(2) or other electron donors and competing electron acceptors influence the dechlorination rate, extent and route of PCB dechlorination. We conclude from the sum of the experimental data that these factors influence apparently the composition of the active microbial community and thus the routes, the rates and the extent of the dehalogenation. The observed effects are due to the specificity of the dehalogenating bacteria which become active as well as changing interactions between the dehalogenating and non-dehalogenating bacteria. Important interactions include the induced changes in the formation and utilization of H(2) by non-dechlorinating and dechlorinating bacteria, competition for substrates and other electron donors and acceptors, and changes in the formation of acidic fermentation products by heterotrophic and autotrophic acidogenic bacteria leading to changes in the pH of the sediments.
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Affiliation(s)
- J Wiegel
- Department of Microbiology and Center for Biological Resource Recovery, University of Georgia, 215 Biological Science Building, Athens, GA, USA
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