Effects of pentachlorophenol on the bacterial denitrification process

Abstract

The use of pentachlorophenol (PCP) was banned or restricted in many countries worldwide because of its adverse influences on the ecological environment and humans. However, the potential disrupting effects of PCP on denitrifying microorganisms have warranted more analysis. In this study, the impacts of PCP on denitrification were investigated by using Paracoccus denitrificans as a model denitrifying bacterium. Compared with the control, the presences of 10 and 50 μM of PCP were found to significantly decrease the denitrification efficiencies from 98.5 to 87.2% and 68.7%, respectively. The mechanism studies showed that PCP induced the generation of reactive oxygen species, which decreased the vital enzymes activities related to glycolysis process, causing the disturbance of the metabolism of P. denitrificans utilizing carbon source (glucose) and the growth of the cell, and subsequently the generation of electron donor (NADH) for denitrification via NAD + reduction was severely depressed. Further studies indicated that PCP also decreased the genes expression of several key enzymes responsible for denitrification, such as napA of nitrate reductase (NAR), nirS of nitrite reductase, norB of nitric oxide reductase, and nosZ of nitrous oxide reductase; however, there was only the enzyme activity of NAR was remarkably inhibited.

Amino-Functionalized NDI-Based MOFs as Unusual “Turn On” and “Turn Off” Fluorescent Sensors for Phenolic Pollutants with Double Solvent Channel Response and Iodine Adsorbents

“…6,7 Besides, pentachlorophenol (PCP) is widely used in agriculture as an important preservative, which is toxic and carcinogenic to human health. 8,9 At present, many detection methods are developed for the determination of nitrophenols and PCP, such as surface-enhanced Raman spectroscopy, 10 high-pressure liquid chromatography (HPLC), 11 electrochemical methods, 12,13 gas chromatography (GC), 14 etc. Nevertheless, some of them still present shortcomings of complicated operation, long detection time, and high cost.…”

“…However, the high toxicity and low degradable characteristics of phenols make them highly susceptible to polluting the ecological environments. Many phenolic compounds have been listed as priority pollutants by the European Union (EU) and the US Environmental Protection Agency (EPA), including nitrophenol, chlorophenol, and aminophenol. − As one of the common pollutants in chemical wastewater, nitrophenol compounds can cause serious harm to human health and the natural environment. , Besides, pentachlorophenol (PCP) is widely used in agriculture as an important preservative, which is toxic and carcinogenic to human health. , At present, many detection methods are developed for the determination of nitrophenols and PCP, such as surface-enhanced Raman spectroscopy, high-pressure liquid chromatography (HPLC), electrochemical methods, , gas chromatography (GC), etc. Nevertheless, some of them still present shortcomings of complicated operation, long detection time, and high cost.…”

Theoretical insights into the gaseous and heterogeneous reactions of halogenated phenols with ˙OH radicals: mechanism, kinetics and role of (TiO2)nclusters in degradation processes

“…8 In 2003, the annual national output of C 6 Cl 5 OH reached approximately 3000 tons in China to wipe out schistosomiasis in the common epidemic areas. 9 In the same year, C 6 Cl 5 OH was classified as a priority pollutant by the U.S. Environmental Protection Agency for its environmental persistence, high toxicity, and probable carcinogenicity. Unlike C 6 F 5 OH or C 6 Cl 5 OH, pentabromophenol (C 6 Br 5 OH), is a widely used brominated flame retardant that exists in landfill leachates containing electronic waste.…”