Dehalococcoides mccartyiStrain JNA in Pure Culture Extensively Dechlorinates Aroclor 1260 According to Polychlorinated Biphenyl (PCB) Dechlorination Process N

2014 ◽  
Vol 48 (16) ◽  
pp. 9187-9196 ◽  
Author(s):  
Sarah L. LaRoe ◽  
Ashwana D. Fricker ◽  
Donna L. Bedard
Keyword(s):  
Pure Culture ◽  
Polychlorinated Biphenyl ◽  
Pcb Dechlorination

scholarly journals Dehalorespiration with Polychlorinated Biphenyls by an Anaerobic Ultramicrobacterium

2008 ◽  
Vol 74 (7) ◽  
pp. 2089-2094 ◽  
Author(s):  
Harold D. May ◽  
Greg S. Miller ◽  
Birthe V. Kjellerup ◽  
Kevin R. Sowers
Keyword(s):  
Polychlorinated Biphenyls ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Contaminated Soil ◽  
Pure Culture ◽  
Treatment Strategies ◽  
Cell Extract ◽  
Contaminated Sediments ◽  
Pcb Dechlorination

ABSTRACT Anaerobic microbial dechlorination is an important step in the detoxification and elimination of polychlorinated biphenyls (PCBs), but a microorganism capable of coupling its growth to PCB dechlorination has not been isolated. Here we describe the isolation from sediment of an ultramicrobacterium, strain DF-1, which is capable of dechlorinating PCBs containing double-flanked chlorines added as single congeners or as Aroclor 1260 in contaminated soil. The isolate requires Desulfovibrio spp. in coculture or cell extract for growth on hydrogen and PCB in mineral medium. This is the first microorganism in pure culture demonstrated to grow by dehalorespiration with PCBs and the first isolate shown to dechlorinate weathered commercial mixtures of PCBs in historically contaminated sediments. The ability of this isolate to grow on PCBs in contaminated sediments represents a significant breakthrough for the development of in situ treatment strategies for this class of persistent organic pollutants.

scholarly journals The Dehalococcoides Population in Sediment-Free Mixed Cultures Metabolically Dechlorinates the Commercial Polychlorinated Biphenyl Mixture Aroclor 1260

2007 ◽  
Vol 73 (8) ◽  
pp. 2513-2521 ◽  
Author(s):  
Donna L. Bedard ◽  
Kirsti M. Ritalahti ◽  
Frank E. Löffler
Keyword(s):  
Polychlorinated Biphenyl ◽  
Anaerobic Bacteria ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Reductive Dehalogenase ◽  
Microbial Reductive Dechlorination ◽  
Pcb Dechlorination ◽  
Bacterial Groups ◽  
Polychlorinated Biphenyl Mixture

ABSTRACT Microbial reductive dechlorination of commercial polychlorinated biphenyl (PCB) mixtures (e.g., Aroclors) in aquatic sediments is crucial to achieve detoxification. Despite extensive efforts over nearly two decades, the microorganisms responsible for Aroclor dechlorination remained elusive. Here we demonstrate that anaerobic bacteria of the Dehalococcoides group derived from sediment of the Housatonic River (Lenox, MA) simultaneously dechlorinate 64 PCB congeners carrying four to nine chlorines in Aroclor 1260 in the sediment-free JN cultures. Quantitative real-time PCR showed that the Dehalococcoides cell titer in JN cultures amended with acetate and hydrogen increased from 7.07 × 106 ± 0.42 × 106 to 1.67 × 108 ± 0.04 × 108 cells/ml, concomitant with a 64.2% decrease of the PCBs with six or more chlorines in Aroclor 1260. No Dehalococcoides growth occurred in parallel cultures without PCBs. Aroclor 1260 dechlorination supported the growth of 9.25 × 108 ± 0.04 × 108 Dehalococcoides cells per μmol of chlorine removed. 16S rRNA gene-targeted PCR analysis of known dechlorinators (i.e., Desulfitobacterium, Dehalobacter, Desulfuromonas, Sulfurospirillum, Anaeromyxobacter, Geobacter, and o-17/DF-1-type Chloroflexi organisms) ruled out any involvement of these bacterial groups in the dechlorination. Our results suggest that the Dehalococcoides population present in the JN cultures also catalyzes in situ dechlorination of Aroclor 1260 in the Housatonic River. The identification of Dehalococcoides organisms as catalysts of extensive Aroclor 1260 dechlorination and our ability to propagate the JN cultures under defined conditions offer opportunities to study the organisms' ecophysiology, elucidate nutritional requirements, identify reductive dehalogenase genes involved in PCB dechlorination, and design molecular tools required for bioremediation applications.

scholarly journals Complete Reductive Dehalogenation of Brominated Biphenyls by Anaerobic Microorganisms in Sediment

1998 ◽  
Vol 64 (3) ◽  
pp. 940-947 ◽  
Author(s):  
Donna L. Bedard ◽  
Heidi M. Van Dort
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Mass Spectrometer ◽  
Polychlorinated Biphenyl ◽  
Electron Capture Detector ◽  
Reductive Dehalogenation ◽  
Contaminated Sediment ◽  
Intermediate Products ◽  
Anaerobic Microorganisms ◽  
Pcb Dechlorination

ABSTRACT We sought to determine whether microorganisms from the polychlorinated biphenyl (PCB)-contaminated sediment in Woods Pond (Lenox, Mass.) could dehalogenate brominated biphenyls. The PCB dechlorination specificities for the microorganisms in this sediment have been well characterized. This allowed us to compare the dehalogenation specificities for brominated biphenyls and chlorinated biphenyls within a single sediment. Anaerobic sediment microcosms were incubated separately at 25°C with 16 different mono- to tetrabrominated biphenyls (350 μM) and disodium malate (10 mM). Samples were extracted and analyzed by gas chromatography with an electron capture detector and a mass spectrometer detector at various times for up to 54 weeks. All of the tested brominated biphenyls were dehalogenated. For most congeners, including 2,6-dibromobiphenyl (26-BB) and 24-25-BB, the dehalogenation began within 1 to 2 weeks. However, for 246-BB and 2-2-BB, debromination was first observed at 7 and 14 weeks, respectively. Most intermediate products did not persist, but when 2-2-BB was produced as a dehalogenation product, it persisted for at least 15 weeks before it was dehalogenated to 2-BB and then to biphenyl. The dehalogenation specificities for brominated and chlorinated biphenyls were similar: meta andpara substituents were generally removed first, andortho substituents were more recalcitrant. However, the brominated biphenyls were better dehalogenation substrates than the chlorinated biphenyls. All of the tested bromobiphenyls, including those with ortho and unflankedmeta and para substituents, were ultimately dehalogenated to biphenyl, whereas their chlorinated counterparts either were not dehalogenation substrates or were only partially dehalogenated. Our data suggest that PCB-dechlorinating microorganisms may be able to dehalogenate brominated biphenyls and may exhibit a relaxed specificity for these substrates.

Microbial Dechlorination of 2,3,5,6-Tetrachlorobiphenyl under Anaerobic Conditions in the Absence of Soil or Sediment

1998 ◽  
Vol 64 (8) ◽  
pp. 2966-2969 ◽  
Author(s):  
Leah Cutter ◽  
Kevin R. Sowers ◽  
Harold D. May
Keyword(s):  
Minimal Medium ◽  
Polychlorinated Biphenyl ◽  
Short Chain Fatty Acids ◽  
Lag Time ◽  
Anaerobic Conditions ◽  
Bacterial Enrichment ◽  
Enrichment Cultures ◽  
Baltimore Harbor ◽  
Enrichment Technique ◽  
Pcb Dechlorination

ABSTRACT Bacterial enrichment cultures developed with Baltimore Harbor (BH) sediments were found to reductively dechlorinate 2,3,5,6-tetrachlorobiphenyl (2,3,5,6-CB) when incubated in a minimal estuarine medium containing short-chain fatty acids under anaerobic conditions with and without the addition of sediment. Primary enrichment cultures formed both meta and orthodechlorination products from 2,3,5,6-CB. The lag time preceding dechlorination decreased from 30 to less than 20 days as the cultures were sequentially transferred into estuarine medium containing dried, sterile BH sediment. In addition, only ortho dechlorination was observed following transfer of the cultures. Sequential transfer into medium without added sediment also resulted in the development of a strict ortho-dechlorinating culture following a lag of more than 100 days. Upon further transfer into the minimal medium without sediment, the lag time decreased to less than 50 days. At this stage all cultures, regardless of the presence of sediment, would produce 2,3,5-CB and 3,5-CB from 2,3,5,6-CB. The strictortho-dechlorinating activity in the sediment-free cultures has remained stable for more than 1 year through several transfers. These results reveal that the classical microbial enrichment technique using a minimal medium with a single polychlorinated biphenyl (PCB) congener selected for ortho dechlorination of 2,3,5,6-CB. Furthermore, this is the first report of sustained anaerobic PCB dechlorination in the complete absence of soil or sediment.

scholarly journals “Dehalococcoides” sp. Strain CBDB1 Extensively Dechlorinates the Commercial Polychlorinated Biphenyl Mixture Aroclor 1260

2009 ◽  
Vol 75 (13) ◽  
pp. 4516-4524 ◽  
Author(s):  
Lorenz Adrian ◽  
Vlasta Dudková ◽  
Katařina Demnerová ◽  
Donna L. Bedard
Keyword(s):  
New York ◽  
Polychlorinated Biphenyl ◽  
Hudson River ◽  
Pcb Congeners ◽  
Aroclor 1248 ◽  
Wide Range ◽  
High Resolution Gas Chromatography ◽  
Pcb Dechlorination ◽  
First Time

ABSTRACT “Dehalococcoides” sp. strain CBDB1 in pure culture dechlorinates a wide range of PCB congeners with three to eight chlorine substituents. Congener-specific high-resolution gas chromatography revealed that CBDB1 extensively dechlorinated both Aroclor 1248 and Aroclor 1260 after four months of incubation. For example, 16 congeners comprising 67.3% of the total PCBs in Aroclor 1260 were decreased by 64%. We confirmed the dechlorination of 43 different PCB congeners. The most prominent dechlorination products were 2,3′,5-chlorinated biphenyl (25-3-CB) and 24-3-CB from Aroclor 1248 and 235-25-CB, 25-25-CB, 24-25-CB, and 235-236-CB from Aroclor 1260. Strain CBDB1 removed flanked para chlorines from 3,4-, 2,4,5-, and 3,4,5-chlorophenyl rings, primarily para chlorines from 2,3,4,5-chlorophenyl rings, primarily meta chlorines from 2,3,4- and 2,3,4,6-chlorophenyl rings, and either meta or para chlorines from 2,3,4,5,6-chlorophenyl rings. The site of attack on the 2,3,4-chorophenyl ring was heavily influenced by the chlorine configuration on the opposite ring. This dechlorination pattern matches PCB Process H dechlorination, which was previously observed in situ both in the Acushnet Estuary (New Bedford, MA) and in parts of the Hudson River (New York). Accordingly, we propose that Dehalococcoides bacteria similar to CBDB1 are potential agents of Process H PCB dechlorination in the environment. This is the first time that a complex naturally occurring PCB dechlorination pattern has been reproduced in the laboratory using a single bacterial strain.

Fine Structural Alterations in Thyroid Follicular Cells (FC) and Changes in Serum Thyroxine Produced by Feeding Polychlorinated Biphenyl (PCB) to Rats

1977 ◽  
Vol 35 ◽  
pp. 498-499
Author(s):  
W.T. Collins ◽  
Charles C. Capen ◽  
Louis Kasza
Keyword(s):  
Feed Efficiency ◽  
Polychlorinated Biphenyl ◽  
Serum Proteins ◽  
Skin Lesions ◽  
Hepatic Necrosis ◽  
Ultrastructural Changes ◽  
Lymphoid Tissues ◽  
Heat Transfer Fluids ◽  
Thyroid Follicular Cells ◽  
Peripheral Metabolism

The widespread contamination of the environment with PCB, a compound used extensively by industry in hydraulic and heat transfer fluids as well as plasticizers and solvents in adhesives and sealants, has resulted in detectable tissue levels in a large portion of the human population, domestic animals, and wildlife. Intoxication with PCB produces severe hepatic necrosis, degeneration of lymphoid tissues and kidney, skin lesions, decreased reproductive performance, reduced feed efficiency, and decreased weight gain. PCB also has been reported to reduce the binding of thyroid hormone to serum proteins and enhance the peripheral metabolism of thyroxine with increased excretion of thyroxine-glucuronide in the bile (Bastomsky, Endocrinology 95: 1150-1155, 1974).The objectives of this investigation were (1) to investigate the histopathologic, histochemical, and ultrastructural changes in thyroid FC produced by the acute (4 week) and chronic (12 week) administration of low (50 ppm) and high (500 ppm) doses of PCB to rats, (2) to correlate these alterations to changes in serum immunoreactive thyroxine concentration, and (3) to investigate the persistence of the effects of PCB on the thyroid gland.

Polychlorinated biphenyl induced hepatocyte alterations

1987 ◽  
Vol 45 ◽  
pp. 716-717
Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal
Keyword(s):  
Lipid Droplets ◽  
Wistar Rats ◽  
Homovanillic Acid ◽  
Polychlorinated Biphenyl ◽  
Corn Oil ◽  
Environmental Pollutants ◽  
Short Term ◽  
Pcb Congeners ◽  
Urinary Levels ◽  
The Brain

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).

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