Compound degraded:Pentachlorophenol

General Description (About POP compound)

Pentachlorophenol (PCP) is an chlorinated aromatic compound used as a pesticide and a disinfectant. It was first produced in the 1930s. PCP has been used as a herbicide, insecticide, fungicide, algaecide, and disinfectant and as an ingredient in antifouling paint. Some applications were in agricultural seeds (for nonfood uses), leather, masonry, wood preservation, cooling-tower water, rope, and paper. It has previously been used in the manufacture of food packaging materials. Its use has declined due to its high toxicity and slow biodegradation.

Biodegradation pathway

Publications

Abstract Title Authors Article Link
Pentachlorophenol (PCP) is a toxic and persistent wood and cellulose preservative extensively used in the past decades. The production process of PCP generates polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) as micropollutants. PCDD/Fs are also known to be very persistent and dangerous for human health and ecosystem functioning. Several physico-chemical and biological technologies have been used to remove PCP and PCDD/Fs from the environment. Bacterial degradation appears to be a cost-effective way of removing these contaminants from soil while causing little impact on the environment. Several bacteria that cometabolize or use these pollutants as their sole source of carbon have been isolated and characterized. This review summarizes current knowledge on the metabolic pathways of bacterial degradation of PCP and PCDD/Fs. PCP can be successfully degraded aerobically or anaerobically by bacteria. Highly chlorinated PCDD/Fs are more likely to be reductively dechlorinated, while less chlorinated PCDD/Fs are more prone to aerobic degradation. The biochemical and genetic basis of these pollutants’ degradation is also described. There are several documented studies of effective applications of bioremediation techniques for the removal of PCP and PCDD/Fs from soil and sediments. These findings suggest that biodegradation can occur and be applied to treat these contaminants. Bacterial Biotransformation of Pentachlorophenol and Micropollutants Formed during Its Production Process Lopez-Echartea et al., 2016 Link
The steady-state growth of a Flavobacterium strain known to utilize pentachlorophenol (PCP) was examined when cellobiose and PCP simultaneously limited its growth rate in continuous culture. A concentration of 600 mg of PCP per liter in influent medium could be continuously degraded without affecting steady-state growth. We measured specific rates of PCP carbon degradation as high as 0.15 +/- 0.01 g (dry weight) of C per h at a growth rate of 0.045 h-1. Comparable specific rates of PCP degradation were obtained and maintained by PCP-adapted, natural consortia of epilithic microorganisms. The consortium results suggest that a fixed-film bioreactor containing a PCP-adapted natural microbial population could be used to treat PCP-contaminated water. Pentachlorophenol degradation: a pure bacterial culture and an epilithic microbial consortium Brown et al., 1986 Link
Fluorescent Pseudomonads strains were considered as plant growth promoting bacteria. They exhibited antagonistic activities against phytopathogens and showed bio-fertilizing properties. The strain Pseudomonas fluorescens PsWw128, isolated from wastewater, can use the pentachlorophenol (PCP) as the sole source of carbon and energy. High-performance liquid chromatography (HPLC) and spectrophotometric methods were used to follow the PCP degradation and biomass PsWw128 formation. However, the removal efficiency of PCP was highly significant. Thus, PsWw128 was able to degrade more than 99% of PCP when this isolate was grown under a high concentration of PCP (250 mg L–1) in a mineral salts medium (MSM). The simultaneous utilization of glucose and PCP indicates the diauxic growth pattern of PsWw128. PCP addition (100 mg L–1) in the growth medium can contribute to a decrease of the antibiotic susceptibility, and increase the biofilm development. In the presence of the toxic pollutant PCP (100, 200 and 250 mg L–1), the antibiotic sensitivity showed a decrease concerning the seven antibiotics tested. Furthermore, the biofilm formation appeared very low with OD600 = 0.075 in the Brain infusion broth supplemented with 25% of glucose, and developed a significant growth with an OD600 = 1.809 in the MSM supplemented with 250 mg L–1 of PCP. Pentachlorophenol degradation by Pseudomonas fluorescens  Ammeri et al., 2017 Link
A bacterial community obtained by continuous enrichment from the microbial population of tannery effluent using pentachlorophenol (PCP) as sole source of carbon and energy, contained four different bacterial species including Serratia marcescens (three isolates, TE1, TE2 and TE4) and Pseudomonas fluorescens (one isolate, TE3). The members of the community grew separately on various chlorinated compounds, carbon and nitrogen sources and exhibited a remarkable ability to utilize PCP. Biodegradation studies revealed a time-dependent disappearance of PCP and its intermediary metabolites, tetrachloro-p-hydroquinone and chlorohydroquinone, and indicated the individual role of members of the community in the degradation of PCP. Enrichment and characterization of a microbial community from tannery effluent for degradation of pentachlorophenol Shah and Thakur. 2002 Link
This research examined the addition of soil to enhance the microbial depletion of two pentachlorophenol (PCP) concentrations in wood flakes from a treated utility pole. Treatments in the first study consisted of wood flakes containing 1540 [micro]g/g PCP mixed with and without soil or microorganisms. By the end of the study, the PCP concentration was reduced by approximately 40 percent in treatments containing wood or wood plus bacterium and reduced by 68 percent in wood inoculated with fungus. PCP reduction was 40, 88, and 95 percent in treatments containing wood plus autoclaved soil and wood plus autoclaved soil plus a bacterium or fungus, respectively. In non-autoclaved soil treatments, PCP concentration was reduced by 88 percent or greater with or without added bacterium or fungus. The addition of non-autoclaved soil significantly enhanced the degradation of PCP compared to autoclaved soil. Degradation was initially faster in fungal-than bacterial-inoculated soil treatments but was equal at the end of the study. The reduction in PCP concentration also corresponded to a reduction in toxicity. Treatments for the second study consisted of PCP-treated wood flakes (15,000 [micro]g/g), wood flakes plus non-autoclaved soil, and wood flakes plus non-autoclaved soil plus added bacterium or fungus. The PCP concentration in the wood flakes was reduced by 32 percent in treatments containing soil plus bacterium and 45 percent in treatments containing soil plus fungus. Results from both studies indicated that non-autoclaved soil addition significantly enhanced microbial degradation of PCP in wood. Soil-enhanced microbial degradation of pentachlorophenol-treated wood Prewitt et al., 2003 Link
A pentachlorophenol (PCP) mineralizing bacterium was isolated from the secondary sludge of pulp and paper mill and identifi as Pseudomonas stutzeri strain CL7. This isolate used PCP as its sole source of carbon and energy and was capable of degrading th compound as indicated by stoichiometric release of chloride and biomass formation. P. stutzeri (CL7) was able to mineralize a hi concentration of PCP (600 mg/L) than any previously reported Pseudomonad with PCP as sole carbon source. As the concentrati of PCP increased from 50 to 600 mg/L, the reduction in the cell growth was observed and the PCP degradation was more than 90 in all studied concentrations. This isolate was able to remove 66.8% of PCP from the secondary sludge of pulp and paper mill wh supplemented with 100 mg/L of PCP and grown for two weeks. This study showed that the removal efficiency of PCP by CL7 w found to be very effective and can be used in PCP remediation of pulp paper mill waste in the environment. Pentachlorophenol degradation by Pseudomonas stutzeri CL7 in the secondary sludge of pulp and paper mill Karn et al., 2010 Link
We sought to elucidate the mechanisms underlying the aerobic dechlorination of the persistent organic pollutants hexachlorobenzene (HCB) and pentachlorophenol (PCP). We performed genomic and heterologous expression analyses of dehalogenase genes in Nocardioides sp. PD653, the first bacterium found to be capable of mineralizing HCB via PCP under aerobic conditions. The hcbA1A2A3 and hcbB1B2B3 genes, which were involved in catalysing the aerobic dechlorination of HCB and PCP, respectively, were identified and characterized; they were classified as members of the two-component flavin-diffusible monooxygenase family. This was subsequently verified by biochemical analysis; aerobic dechlorination activity was successfully reconstituted in vitro in the presence of flavin, NADH, the flavin reductase HcbA3, and the HCB monooxygenase HcbA1. These findings will contribute to the implementation of in situ bioremediation of HCB- or PCP-contaminated sites, as well as to a better understanding of bacterial evolution apropos their ability to degrade heavily chlorinated anthropogenic compounds under aerobic conditions. Mechanisms of aerobic dechlorination of hexachlorobenzene and pentachlorophenol by Nocardioides sp. PD653 Ito. 2021 Link
Anaerobically digested municipal sewage sludge which had been acclimated to monochlorophenol degradation for more than 2 years was shown to degrade pentachlorophenol (PCP). Di-, tri-, and tetrachlorophenols accumulated when PCP was added to the individual acclimated sludges. When the 2-chlorophenol- (2-CP), 3-CP-, and 4-CP-acclimated sludges were mixed in equal volumes, PCP was completely dechlorinated. The same results were obtained in sludge acclimated to the three monochlorophenol isomers simultaneously. With repeated PCP additions, 3,4,5,-trichlorophenol, 3,5-dichlorophenol, and 3-CP accumulated in less than stoichiometric amounts. All chlorinated compounds disappeared after PCP additions were stopped. All chlorinated compounds disappeared after PCP additions were stopped. Incubations with [14C]PCP resulted in 66% of the added 14C being mineralized to 14CO2 and 14CH4. Technical-grade PCP was found to be degraded initially at a rate very similar to that of reagent-grade PCP, but after repeated additions, the technical PCP was degraded more slowly. Pentabromophenol was also rapidly degraded by the mixture of acclimated sludges. These results clearly show the complete reductive dechlorination of PCP by the combined activities of three chlorophenol-degrading populations. Complete reductive dechlorination and mineralization of pentachlorophenol by anaerobic microorganisms. Mikesell and Boyd. 1986 Link
Many pentachlorophenol- (PCP-) contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, and high salt concentrations. PCP-degrading microorganisms, adapted to grow and prosper in these environments, play an important role in the biological treatment of polluted extreme habitats. A PCP-degrading bacterium was isolated and characterized from arid and saline soil in southern Tunisia and was enriched in mineral salts medium supplemented with PCP as source of carbon and energy. Based on 16S rRNA coding gene sequence analysis, the strain FAS23 was identified as Janibacter sp. As revealed by high performance liquid chromatography (HPLC) analysis, FAS23 strain was found to be efficient for PCP removal in the presence of 1% of glucose. The conditions of growth and PCP removal by FAS23 strain were found to be optimal in neutral pH and at a temperature of 30°C. Moreover, this strain was found to be halotolerant at a range of 1–10% of NaCl and able to degrade PCP at a concentration up to 300?mg/L, while the addition of nonionic surfactant (Tween 80) enhanced the PCP removal capacity. Pentachlorophenol Degradation by Janibacter sp., a New Actinobacterium Isolated from Saline Sediment of Arid Land Khessairi et al., 2014 Link