Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.17 (PCE)
 1,301 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tetrachloroethylene (perchloroethylene, PCE) is a suspected carcinogen and a common groundwater contaminant. Although PCE is highly resistant to aerobic biodegradation, it is subject to reductive dechlorination reactions in a variety of anaerobic habitats. The data presented here clearly establish that axenic cultures of Methanosarcina sp. strain DCM dechlorinate PCE to trichloroethylene and that this is a biological reaction. Growth on methanol, acetate, methylamine, and trimethylamine resulted in PCE dechlorination. The reductive dechlorination of PCE occurred only during methanogenesis, and no dechlorination was noted when CH4 production ceased. There was a clear dependence of the extent of PCE dechlorination on the amount of methanogenic substrate (methanol) consumed. The amount of trichloroethylene formed per millimole of CH4 formed remained essentially constant for a 20-fold range of methanol concentrations and for growth on acetate, methylamine, and trimethylamine. These results suggest that the reducing equivalents for PCE dechlorination are derived from CH4 biosynthesis and that the extent of chloroethylene dechlorination can be enhanced by stimulating methanogenesis. It is proposed that electrons transferred during methanogenesis are diverted to PCE by a reduced electron carrier involved in methane formation.
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PMID:Dependence of tetrachloroethylene dechlorination on methanogenic substrate consumption by Methanosarcina sp. strain DCM. 322 63

We studied the spatial and temporal distribution patterns of Chlorinated Volatile Organic Compounds (CVOCs) in the karst aquifers in northern Puerto Rico (1982-2013). Seventeen CVOCs were widely detected across the study area, with the most detected and persistent contaminated CVOCs including trichloroethylene (TCE), tetrachloroethylene (PCE), carbon tetrachloride (CT), chloroform (TCM), and methylene chloride (DCM). Historically, 471 (76%) and 319 (52%) of the 615 sampling sites have CVOC concentrations above the detection limit and maximum contamination level (MCL), respectively. The spatiotemporal patterns of the CVOC concentrations showed two clusters of contaminated areas, one near the Superfund site "Upjohn" and another near "Vega Alta Public Supply Wells." Despite a decreasing trend in concentrations, there is a general northward movement and spreading of contaminants even beyond the extent of known sources of the Superfund and landfill sites. Our analyses suggest that, besides the source conditions, karst characteristics (high heterogeneity, complex hydraulic and biochemical environment) are linked to the long-term spatiotemporal patterns of CVOCs in groundwater.
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PMID:Spatiotemporal changes of CVOC concentrations in karst aquifers: analysis of three decades of data from Puerto Rico. 2552 55