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)

Radiolabeled tetrachloroethene (PCE) and carbon tetrachloride (CT) were added to batch systems containing a lactate-enrichment culture displaying apparent dehalorespiration abilities to analyze the influence of mixtures on product distribution. Both CT and PCE were readily dechlorinated, although significant carbon disulfide (CS2) formation was observed during CT transformation. Calculated 1,2-14C-PCE recoveries for biotic treatments were between 91 and 104%, but an inability to recover products such as CS2 led to lower recoveries of 14C-CT (55 to 62%). While the majority of activity in 14C-CT-spiked treatments was recovered in the volatile fraction, 14CO2 increased significantly over time. 1,2-14C-PCE was primarily recovered in volatile and non-strippable fractions, but a significant increase in 14CO2 relative to cell-free controls suggested that the presence of a non-specific dechlorination pathway complementing dehalorespiration. The addition of both CT and PCE inhibited the transformation of the individual compounds and reduced the percentages recovered as 14CO2. However, the magnitude of these reductions was not severe and appeared to be the result of slower overall transformation rather than a complete inhibition of mineralization pathways.
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PMID:Product distribution during transformation of multiple contaminants by a high-rate, tetrachlorethene-dechlorinating enrichment culture. 1199 27

Tetrachloroethene (PCE) and carbon tetrachloride (CT) were simultaneously transformed in a packed column that was bioaugmented with the Evanite culture (EV). The data presented here have been obtained over a period of 1930days. Initially the column was continuously fed synthetic groundwater with PCE (0.1mM), sulfate (SO4(2-)) (0.2mM) and formate (2.1mM) or lactate (1.1mM), but not CT. In these early stages of the study the effluent H2 concentrations ranged from 7 to 19nM, and PCE was transformed to ethene (ETH) (81 to 85%) and vinyl chloride (VC) (11 to 17%), and SO4(2-) was completely reduced when using either lactate or formate as electron donors. SO4(2-) reduction occurred concurrently with cis-DCE and VC dehalogenation. Formate was a more effective substrate for promoting dehalogenation based on electron donor utilization efficiency. Simultaneous PCE and CT tests found CT (0.015mM) was completely transformed with 20% observed as chloroform (CF) and trace amounts of chloromethane (CM) and dichloromethane (DCM), but no methane (CH4) or carbon disulfide (CS2). PCE transformation to ETH improved with CT addition in response to increases in H2 concentrations to 160nM that resulted from acetate formation being inhibited by either CT or CF. Lactate fermentation was negatively impacted after CT transformation tests, with propionate accumulating, and H2 concentrations being reduced to below 1nM. Under these conditions both SO4(2-) reduction and dehalogenation were negatively impacted, with sulfate reduction not occurring and PCE being transformed to cis-dichloroethene (c-DCE) (52%) and VC (41%). Upon switching to formate, H2 concentrations increased to 40nM, and complete SO4(2-) reduction was achieved, while PCE was transformed to ETH (98%) and VC (1%), with no acetate detected. Throughout the study PCE dehalogenation to ethene was positively correlated with the effluent H2 concentrations.
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PMID:Simultaneous anaerobic transformation of tetrachloroethene and carbon tetrachloride in a continuous flow column. 2718 41