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.

Production of metabolites from chlorobiphenyls by resting cells ofPseudomonasstrain LB400 after growth on different carbon sources

1999 ◽  
Vol 45 (2) ◽  
pp. 178-184 ◽  
Author(s):  
K A Billingsley ◽  
S M Backus ◽  
O P Ward
Keyword(s):  
Carbon Source ◽  
Polychlorinated Biphenyl ◽  
Carbon Sources ◽  
Resting Cells ◽  
Metabolite Formation ◽  
Chlorobenzoic Acid ◽  
Metabolite Production ◽  
Pcb Congeners ◽  
Chlorobenzoic Acids ◽  
General Order

Cells of Pseudomonas strain LB400, grown on biphenyl, glucose, or glycerol, transformed polychlorinated biphenyl (PCB) congeners into chlorobenzoic acid (CBA) metabolites. Transformation of the PCB congeners, 2,3-chlorobiphenyl (CBP), 2,2'-CBP, 2,5,4'-CBP, and 2,4,2',4'-CBP, produced the metabolites, 2,3-CBA, 2-CBA, 4-CBA, and 2,4-CBA, respectively. Rates and extents of PCB transformation and metabolite formation were highest with biphenyl-grown cells. Intermediate rates of metabolite production were observed with glycerol-grown cells, and lowest rates of production were found with glucose-grown cells. Regardless of carbon source, the rate of degradation of congeners was faster than the rate of production of CBAs. Relative rates of PCB transformation and metabolite production from different congeners with cells grown on a particular substrate followed the same general order, 2,3-CBA (from 2,3-CBP) > 2-CBA (from 2,2'-CBP) > 4-CBA (from 2,5,4'-CBP) > 2,4-CBA (from 2,4,2',4'-CBP). Pseudomonas strain LB400 appeared unable to grow on any of the chlorobenzoic acids. However, Pseudomonas strain LB400 cells grown on biphenyl appeared capable of degrading 2-CBA and 2,3-CBA but not 4-CBA nor 2,4-CBA. Cells grown on glycerol appeared unable to metabolize any CBAs.Key words: polychlorinated biphenyls, metabolites, Pseudomonas LB400.

Comparison of the degradation patterns of polychlorinated biphenyl congeners in Aroclors byPseudomonasstrain LB400 after growth on various carbon sources

1997 ◽  
Vol 43 (12) ◽  
pp. 1172-1179 ◽  
Author(s):  
K. A. Billingsley ◽  
C. Juneson ◽  
O. P. Ward ◽  
S. M. Backus
Keyword(s):  
Polychlorinated Biphenyls ◽  
Rate Constants ◽  
Polychlorinated Biphenyl ◽  
Carbon Sources ◽  
Transformation Rate ◽  
Resting Cells ◽  
Growth Substrate ◽  
Aroclor 1242 ◽  
Time Courses

Resting cells of Pseudomonas strain LB400, grown on biphenyl, transformed 80, 50, and 17% of Aroclor 1242, 1254, and 1260, respectively. Resting cells grown on glucose or glycerol also transformed these polychlorinated biphenyl (PCB) mixtures to the extent of 60, 35, and 9% for Aroclors 1242, 1254, and 1260, respectively. Time courses of the transformation of the separated individual congeners in the Aroclors were plotted and used to determine the transformation rate constants (k). By analysis of the rate constants, it was concluded that the order of degradation of the different congeners in an Aroclor were similar regardless of the growth substrate. In general, k values for the conversion of a particular congener were lower for cells grown on glucose or glycerol compared with cells grown on biphenyl. Generally, k values for the transformation of the same congener in different Aroclors were not the same: rate constants had highest values for the congener in Aroclor 1242 and lowest values in Aroclor 1260. The data allowed congeners to be grouped according to their relative rates of degradation. The ratio of k values for transformation of individual congeners in Aroclors by cells grown on biphenyl and glucose were not constant.Key words: Pseudomonas strain LB400, polychlorinated biphenyls, Aroclors, transformation, resting cells.

scholarly journals Pyruvate accelerates palladium reduction by regulating catabolism and electron transfer pathway in Shewanella oneidensis

2021 ◽  
Author(s):  
Yuan-Yuan Cheng ◽  
Wen-Jing Wang ◽  
Shi-Ting Ding ◽  
Ming-Xing Zhang ◽  
Ai-Guo Tang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Carbon Source ◽  
Time Window ◽  
Carbon Sources ◽  
Shewanella Oneidensis ◽  
Underlying Mechanism ◽  
Extracellular Electron Transfer ◽  
Resting Cells ◽  
Electron Transfer Pathway ◽  
Specific Regulation

Shewanella oneidensis is a model strain of the electrochemical active bacteria (EAB) because of its strong capability of extracellular electron transfer (EET) and genetic tractability. In this study, we investigated the effect of carbon sources on EET in S. oneidensis by using reduction of palladium ions (Pd(II)) as a model and found that pyruvate greatly accelerated the Pd(II) reduction compared with lactate by resting cells. Both Mtr pathway and hydrogenases played a role in Pd(II) reduction when pyruvate was used as a carbon source. Furthermore, in comparison with lactate-feeding S. oneidensis, the transcriptional levels of formate dehydrogenases involving in pyruvate catabolism, Mtr pathway, and hydrogenases in pyruvate-feeding S. oneidensis were up-regulated. Mechanistically, the enhancement of electron generation from pyruvate catabolism and electron transfer to Pd(II) explains the pyruvate effect on Pd(II) reduction. Interestingly, a 2-h time window is required for pyruvate to regulate transcription of these genes and profoundly improve Pd(II) reduction capability, suggesting a hierarchical regulation for pyruvate sensing and response in S. oneidensis. IMPORTANCE The unique respiration of EET is crucial for the biogeochemical cycling of metal elements and diverse applications of EAB. Although a carbon source is a determinant factor of bacterial metabolism, the research into the regulation of carbon source on EET is rare. In this work, we reported the pyruvate-specific regulation and improvement of EET in S. oneidensis and revealed the underlying mechanism, which suggests potential targets to engineer and improve the EET efficiency of this bacterium. This study sheds light on the regulatory role of carbon sources in anaerobic respiration in EAB, providing a way to regulate EET for diverse applications from a novel perspective.

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.

scholarly journals Catabolism of Benzoate and Phthalate in Rhodococcus sp. Strain RHA1: Redundancies and Convergence

2005 ◽  
Vol 187 (12) ◽  
pp. 4050-4063 ◽  
Author(s):  
Marianna A. Patrauchan ◽  
Christine Florizone ◽  
Manisha Dosanjh ◽  
William W. Mohn ◽  
Julian Davies ◽  
...  
Keyword(s):  
Polychlorinated Biphenyl ◽  
Carbon Sources ◽  
Growth Conditions ◽  
Lag Phase ◽  
Gene Products ◽  
Wild Type ◽  
Bacterial Genomes ◽  
Catabolic Genes ◽  
Genes Encoding ◽  
Proteomic Analyses

ABSTRACT Genomic and proteomic approaches were used to investigate phthalate and benzoate catabolism in Rhodococcus sp. strain RHA1, a polychlorinated biphenyl-degrading actinomycete. Sequence analyses identified genes involved in the catabolism of benzoate (ben) and phthalate (pad), the uptake of phthalate (pat), and two branches of the β-ketoadipate pathway (catRABC and pcaJIHGBLFR). The regulatory and structural ben genes are separated by genes encoding a cytochrome P450. The pad and pat genes are contained on a catabolic island that is duplicated on plasmids pRHL1 and pRHL2 and includes predicted terephthalate catabolic genes (tpa). Proteomic analyses demonstrated that the β-ketoadipate pathway is functionally convergent. Specifically, the pad and pat gene products were only detected in phthalate-grown cells. Similarly, the ben and cat gene products were only detected in benzoate-grown cells. However, pca-encoded enzymes were present under both growth conditions. Activity assays for key enzymes confirmed these results. Disruption of pcaL, which encodes a fusion enzyme, abolished growth on phthalate. In contrast, after a lag phase, growth of the mutant on benzoate was similar to that of the wild type. Proteomic analyses revealed 20 proteins in the mutant that were not detected in wild-type cells during growth on benzoate, including a CatD homolog that apparently compensated for loss of PcaL. Analysis of completed bacterial genomes indicates that the convergent β-ketoadipate pathway and some aspects of its genetic organization are characteristic of rhodococci and related actinomycetes. In contrast, the high redundancy of catabolic pathways and enzymes appears to be unique to RHA1 and may increase its potential to adapt to new carbon sources.

Application of Rhamnolipid Biosurfactant for Removing Polychlorinated Biphenyls from Contaminated Soil

2011 ◽  
Vol 233-235 ◽  
pp. 608-613 ◽  
Author(s):  
You Shi Liu ◽  
Man Ying Ma ◽  
Zhou Shi
Keyword(s):  
Carbon Source ◽  
Polychlorinated Biphenyls ◽  
Contaminated Soils ◽  
Negative Impact ◽  
Cell System ◽  
Resting Cells ◽  
Cell Systems ◽  
Resting Cell ◽  
Growing Cell ◽  
Rhamnolipid Biosurfactant

Rhamnolipid (RL) was used to study the removing of polychlorinated biphenyls (PCBs) from contaminated soils. The results showed that RL obviously enhanced desorption of PCBs from soils and RL was more effective than POE(6).Pseudomonas strainLB400 was able to grow rapidly in the medium with RL, POE(6) or biphenyl as carbon source. PCBs biodegraded in growing cells were greater than that in resting cells. In growing cells with RL as carbon source, when the incubating time reached 72 h, PCBs Biodegraded was 98.7% and increased by 0.5% compared with that with biphenyl as carbon source. PCBs degraded were the lowest in all kinds of cell systems with POE(6) as carbon source. In the growing cell system,P.LB400 was able to fully utilize RL, so the cell density and PCBs Biodegraded rapidly increased with the increase of the concentration of RL. However, in the resting cell system, RL had negative impact on biodegradation of PCBs.

scholarly journals Phosphotransferase System-Dependent Extracellular Growth of Listeria monocytogenes Is Regulated by Alternative Sigma Factors σLand σH

2014 ◽  
Vol 80 (24) ◽  
pp. 7673-7682 ◽  
Author(s):  
Siyun Wang ◽  
Renato H. Orsi ◽  
Silin Tang ◽  
Wei Zhang ◽  
Martin Wiedmann ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Carbon Source ◽  
Parent Strain ◽  
Carbon Sources ◽  
Maximum Growth ◽  
Fine Tuning ◽  
Lag Phase ◽  
Phosphotransferase System ◽  
Phase Duration ◽  
Content Type

ABSTRACTAlternative sigma (σ) factors and phosphotransferase systems (PTSs) play pivotal roles in the environmental adaptation and virulence ofListeria monocytogenes. The growth of theL. monocytogenesparent strain 10403S and 15 isogenic alternative σ factor mutants was assessed in defined minimal medium (DM) with PTS-dependent or non-PTS-dependent carbon sources at 25°C or 37°C. Overall, our results suggested that the regulatory effect of alternative σ factors on the growth ofL. monocytogenesis dependent on the temperature and the carbon source. One-way analysis of variance (one-way ANOVA) showed that the factor “strain” had a significant effect on the maximum growth rate (μmax), lag phase duration (λ), and maximum optical density (ODmax) in PTS-dependent carbon sources (P< 0.05) but not in a non-PTS-dependent carbon source. Also, the ODmaxwas not affected by strain for any of the three PTS-dependent carbon sources at 25°C but was affected by strain at 37°C. Monitoring by quantitative real-time PCR (qRT-PCR) showed that transcript levels forlmo0027, a glucose-glucoside PTS permease (PTSGlc-1)-encoding gene, were higher in the absence of σL, and lower in the absence of σH, than in the parent strain. Our data thus indicate that σLnegatively regulateslmo0027and that the increased μmaxobserved for the ΔsigLstrain in DM with glucose may be associated with increased expression of PTSGlc-1 encoded bylmo0027. Our findings suggest that σHand σLmediate the PTS-dependent growth ofL. monocytogenesthrough complex transcriptional regulations and fine-tuning of the expression of specificptsgenes, includinglmo0027. Our findings also reveal a more important and complex role of alternative σ factors in the regulation of growth in different sugar sources than previously assumed.

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.

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).

Effect of carbon source on Phenobarbital metabolism by Rhizopus stolonifer

2010 ◽  
Vol 3 (2) ◽  
pp. 1022-1027
Author(s):  
Kavitha K ◽  
Asha S ◽  
Hima Bindu T.V.L ◽  
Vidyavathi M
Keyword(s):  
Carbon Source ◽  
High Performance ◽  
Carbon Sources ◽  
In Vitro Models ◽  
Rhizopus Stolonifer ◽  
Safety And Efficacy ◽  
Alternative Systems ◽  
Toxicological Studies ◽  
Microbial Model

The safety and efficacy of a drug is based on its metabolism or metabolite formed. The metabolism of drugs can be studied by different in vitro models, among which microbial model became popular. In the present study, eight microbes were screened for their ability to metabolize phenobarbital in a manner comparable to humans with a model to develop alternative systems to study human drug metabolism. Among the different microbes screened, a filamentous fungi Rhizopus stolonifer metabolized phenobarbital to its metabolite which is used for further pharmacological and toxicological studies. The transformation of phenobarbital was identified by high- performance liquid chromatography (HPLC). Interestingly, Rhizopus stolonifer sample showed an extra metabolite peak at 3.11min. compared to its controls. The influence of different carbon sources in media used for growth of fungus, on metabolite production was studied, to find its effect in production of metabolite as the carbon source may influence the growth of the cell.

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