scholarly journals Establishment of a Polychlorinated Biphenyl-Dechlorinating Microbial Consortium, Specific for Doubly Flanked Chlorines, in a Defined, Sediment-Free Medium

2000 ◽  
Vol 66 (1) ◽  
pp. 49-53 ◽  
Author(s):  
Qingzhong Wu ◽  
Kevin R. Sowers ◽  
Harold D. May
Keyword(s):  
South Carolina ◽  
Polychlorinated Biphenyls ◽  
Polychlorinated Biphenyl ◽  
Microbial Consortium ◽  
Enrichment Culture ◽  
Estuarine Sediment ◽  
The Other ◽  
Free Medium ◽  
Pcb Congeners ◽  
Carbon Bonds

ABSTRACT Estuarine sediment from Charleston Harbor, South Carolina, was used as inoculum for the development of an anaerobic enrichment culture that specifically dechlorinates doubly flanked chlorines (i.e., chlorines bound to carbon that are flanked on both sides by other chlorine-carbon bonds) of polychlorinated biphenyls (PCBs). Dechlorination was restricted to the para chlorine in cultures enriched with 10 mM fumarate, 50 ppm (173 μM) 2,3,4,5-tetrachlorobiphenyl, and no sediment. Initially the rate of dechlorination decreased upon the removal of sediment from the medium. However, the dechlorinating activity was sustainable, and following sequential transfer in a defined, sediment-free estuarine medium, the activity increased to levels near that observed with sediment. The culture was nonmethanogenic, and molybdate, ampicillin, chloramphenicol, neomycin, and streptomycin inhibited dechlorination activity; bromoethanesulfonate and vancomycin did not. Addition of 17 PCB congeners indicated that the culture specifically removes double flanked chlorines, preferably in the para position, and does not attack ortho chlorines. This is the first microbial consortium shown to para or metadechlorinate a PCB congener in a defined sediment-free medium. It is the second PCB-dechlorinating enrichment culture to be sustained in the absence of sediment, but its dechlorinating capabilities are entirely different from those of the other sediment-free PCB-dechlorinating culture, an ortho-dechlorinating consortium, and do not match any previously published Aroclor-dechlorinating patterns.

Dependencies of Polychlorinated Biphenyl Concentrations Measured at the Great Lakes on Climate Variables

2020 ◽  
Author(s):  
Sandy Ubl ◽  
Martin Scheringer
Keyword(s):  
Wind Speed ◽  
Great Lakes ◽  
Wind Direction ◽  
Seasonal Cycle ◽  
Large Scale ◽  
Polychlorinated Biphenyl ◽  
The Other ◽  
Small Scale ◽  
Local Conditions ◽  
Pcb Congeners

<p>Polychlorinated biphenyls (PCBs) are persistent and hazardous chemicals that are still detected in the atmosphere and other environmental compartments although their production was banned several decades ago. At the Great Lakes region PCBs have been monitored via the IADN network since 1993. In this study, we report results from seven different PCB congeners measured at six different sites around the Great Lakes. The PCBs exhibit a strong seasonal cycle with highest concentrations in summer and lowest concentrations in winter. The concentrations measured in Chicago and Cleveland are higher compared to the concentrations reported from more remote stations. We evaluated the correlations for the seven PCB congeners at each station. PCB-53,-101,-118 and -138 are highly correlated at each of the six stations. PCB-180 is the least correlated with all the other PCBs. This is explicitly true for Eagle Harbor, where PCB-180 and -153 are not correlated with the other 6 PCBs. This may be explained by the less pronounced seasonal cycle of these heavier PCBs at Eagle Harbor. We observed significant correlations between PCB-28 concentrations at the remote stations, but PCB concentrations at the stations of Chicago and Cleveland are only poorly correlated with PCB concentrations at the other stations. The weak correlation of the PCB concentrations measured at the different stations and the relatively high concentrations of the PCB congeners at each station indicate that local conditions and small scale processes (sources, temperature, wind direction, wind speed) dictate the spatial distribution of the  PCBs. We will feed available data on temperature, wind speed, wind direction, emissions, precipitation, ice cover of the Great Lakes and large scale atmospheric teleconnection patterns into a General Additive Model (GAM) to further investigate the relationships between the measured PCB concentrations and selected environmental conditions and atmospheric parameters.<span> </span></p>

scholarly journals Effect of polychlorinated biphenyls on the secretion of oxytocin from luteal and granulosa cells in cow: possible involvement of glucocorticoid receptors

2012 ◽  
Vol 51 (No. 7) ◽  
pp. 391-398
Author(s):  
Mlynarczuk JJ ◽  
J. Kotwica
Keyword(s):  
Polychlorinated Biphenyls ◽  
Granulosa Cells ◽  
Glucocorticoid Receptors ◽  
The Other ◽  
Luteal Cells ◽  
Pcb Congeners ◽  
Ovarian Cells ◽  
Affect Cell Viability ◽  
Pcb 126 ◽  
The One

Polychlorinated biphenyls (PCBs) stimulate oxytocin secretion from bovine granulosa and luteal cells. Since oxytocin on the one hand is released from ovarian cells by cortisol and on the other hand PCBs can be bound by glucocorticoid receptors (GCr), we have tested the hypothesis that PCBs acting via GCr can stimulate oxytocin secretion. In preliminary studies the effect of RU486 (GCr blocker) on cells viability was tested. Thereafter, a selected dose of RU486 (10<sup>5</sup>M), which did not affect cell viability, was used in further experiments. It appears that this dose of RU486 completely blocked GCr against cortisol-stimulated oxytocin secretion, in both types of cells. Furthermore, granulosa cells (10<sup>5</sup>) from follicles of two sizes (&gt;1 cm &lt; in diameter) and luteal cells (10<sup>5</sup>) from day 5&ndash;10 of estrous cycle were incubated for 72 h with congeners of PCB (126, 77 or 153) at doses of 1, 10 or 100&nbsp;ng/ml each, separately or jointly with RU486. The effect of PCB 77 and 153 on oxytocin secretion was blocked by RU486, but it did not change the effect evoked by PCB126 in both granulosa and luteal cells. We assume that some PCB congeners can affect oxytocin secretion from granulosa and luteal cells acting via GCr.

scholarly journals Differential Enantioselective Transformation of Atropisomeric Polychlorinated Biphenyls by Multiple Bacterial Strains with Different Inducing Compounds

2002 ◽  
Vol 68 (11) ◽  
pp. 5756-5759 ◽  
Author(s):  
Andrew C. Singer ◽  
Charles S. Wong ◽  
David E. Crowley
Keyword(s):  
Polychlorinated Biphenyls ◽  
Polychlorinated Biphenyl ◽  
Bacterial Strains ◽  
Pcb Congeners ◽  
Degrading Bacteria

ABSTRACT Five polychlorinated biphenyl (PCB)-degrading bacteria were tested for the ability to differentiate between the enantiomers of four atropisomeric PCB congeners (2,2′,3,6-tetra-CB; 2,2′,3,3′,6-penta-CB; 2,2′,3,4′,6-penta-CB; and 2,2′,3,5′,6-penta-CB) after growth in the presence of tryptone-soytone, biphenyl, carvone, or cymene. Enantioselectivity was shown to vary with respect to strain, congener, and cosubstrate.

Studies on the transformation of selected polychlorinated biphenyl congeners by Pseudomonas strain LB 400

1997 ◽  
Vol 43 (8) ◽  
pp. 782-788 ◽  
Author(s):  
K. A. Billingsley ◽  
O. P. Ward ◽  
S. M. Backus
Keyword(s):  
Carbon Source ◽  
Polychlorinated Biphenyls ◽  
Incubation Period ◽  
Polychlorinated Biphenyl ◽  
Carbon Sources ◽  
Lag Phase ◽  
Resting Cells ◽  
Major Objective ◽  
Pcb Congeners ◽  
Degradation Medium

Resting cells of Pseudomonas strain LB400 are known to transform polychlorinated biphenyls (PCBs) when the cells are previously grown on biphenyl. In this study, PCB transformation was also observed in resting cells grown on other substrates such as glucose and glycerol. The presence of PCB congeners in the growth medium increased the lag phase for the growth of cells on a biphenyl substrate but not on a glycerol substrate. Supplementation of the degradation medium with biphenyl dramatically decreased the rate of PCB congener transformation, while the presence of glycerol or glucose had little or no effect on PCB transformation rates. Removal rates with biphenyl-grown cells in the standard degradation medium for 2,4,2′,4′-tetrachlorobiphenyl, 2,4,5,2′,5′-pentachlorobiphenyl, and 2,3-dichlorobiphenyl were 1.06, 1.66, and 224 μmol/(L∙h), respectively. Relative rates of transformation of 2,3-dichlorobiphenyl by biphenyl-, glucose-, and glycerol-grown cells were 100:36:36 and were similar to the relative rates of transformation of 2,4,5,2′,5′-pentachlorobiphenyl (100:33:42). The presence of PCBs adversely affected cell viability of biphenyl-grown cells over a 48-h incubation period and may explain the decline observed in PCB conversion capacity over the same incubation period. A major objective of this study was to investigate the significance of using biphenyl as the carbon source for growth of Pseudomonas strain LB400 cells capable of PCB transformation. Our findings indicate that, whereas higher rates of transformation of PCBs are observed with biphenyl-grown cells, cells grown on other carbon sources retain PCB-transforming enzymes. In addition, it has been demonstrated that biphenyl inhibits transformation of PCBs by the organism, whereas glycerol or glucose does not.Key words: Pseudomonas strain LB400, polychlorinated biphenyls, degradation, biphenyl.

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).

scholarly journals Polychlorinated biphenyls and risk of hepatocellular carcinoma in the population living in a highly polluted area in Italy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francesco Donato ◽  
Marco Moneda ◽  
Nazario Portolani ◽  
Angelo Rossini ◽  
Sarah Molfino ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Polychlorinated Biphenyls ◽  
Serum Levels ◽  
Polluted Area ◽  
Sufficient Evidence ◽  
Pcb Congeners ◽  
Non Hodgkin Lymphoma ◽  
And Gender ◽  
Few Data ◽  
Incident Cases

AbstractPolychlorinated biphenyls (PCBs) are human carcinogens, based on sufficient evidence for melanoma and limited evidence for non-Hodgkin lymphoma and breast cancer. Few data are available for liver cancer, although PCBs cause it in rats and determined liver damage in poisoned people. We investigated the association between PCB serum levels and hepatocellular carcinoma (HCC) with a case–control study in a PCB-polluted area in North Italy. We enrolled prospectively 102 HCC incident cases and 102 age and gender-matched hospital controls. Serum concentrations of 33 PCB congeners were determined by a gas chromatograph coupled to mass spectrometry. Of 102 HCC cases, 62 who had lost < 3 kg of body weight in past 3 years were included in the analysis (67.7% males, mean age 68 years). The odds ratio (OR) for HCC for 3rd compared to 1st tertile of PCB distribution was 1.76 (95% confidence interval 0.62–5.03) for total PCB, adjusting for socio-demographic variables and risk factors for HCC by logistic regression. For most PCB congeners, ORs > 1.5 or 2 were found, although the 95% CIs included the null value for almost all of them. This preliminary study suggests that PCBs might play a role in HCC development.

Effects of pH and alkalinity on sulfur-denitrification in a biological granular filter

1996 ◽  
Vol 34 (1-2) ◽  
pp. 355-362 ◽  
Author(s):  
Hiroaki Furumai ◽  
Hideki Tagui ◽  
Kenji Fujita
Keyword(s):  
Enrichment Culture ◽  
Nitrite Reduction ◽  
The Other ◽  
Nitrite Accumulation ◽  
Ph Dependency ◽  
Effects Of Ph ◽  
Rapid Removal ◽  
Nitrate And Nitrite ◽  
The Relationship ◽  
Biological Filters

Two laboratory-scale biological filters were operated to investigate the effects of alkalinity and pH on removal of nitrate and nitrite in sulfur denitrification filter processes. The concentration of sodium bicarbonate in the feed media was changed from 120 to 240 mg/l during about 3 months in a filter (Run A). The other filter was initially fed with 300 mg/l and then with 240 mg/l (Run B). The performance of the filter was monitored by measuring pH, nitrate, nitrite, sulfate, alkalinity, and thiosulfate. Nitrate concentration in effluent rapidly decreased to lower levels within several days for both filters after inoculation of enrichment culture of sulfur denitrifiers. However there was a large difference in removal of nitrite. When rapid removal of nitrate took place, nitrite accumulation was observed and remained while the bicarbonate concentration was 120 and 150 mg/l. On the other hand the nitrite accumulation disappeared when more bicarbonate (240 and 300 mg/l) was supplied. The experimental results indicated that the nitrite accumulation was closely related to pH condition and alkalinity level in the filter. The stable data of effluent water quality for 5 cases were collected and the relationship discussed between nitrite concentration and pH in effluents. The relationship indicated a strong pH dependency on nitrite accumulation below pH of 7.4. The pH condition around 7 is not so inhibitory to biological activity. Therefore, the pH within the biofilm would be low enough to suppress the nitrite reduction by sulfur denitrifiers, while the pH in effluent was not in the inhibitory range. It was recommended to keep the pH higher than 7.4 to prevent nitrite accumulation in the sulfur denitrification filter.

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