Biodegradation of hexabromocyclododecane by Rhodopseudomonas palustris YSC3 strain: A free-living nitrogen-fixing bacterium isolated in Taiwan
Journal
Chemosphere
Journal Volume
246
Date Issued
2020
Author(s)
Abstract
The persistent organic pollutant, brominated flame retardant, hexabromocyclododecane (HBCD), identified as an emerging contaminant has been detected in various environmental matrix. The increased level of this toxic organic compound in the environment has been associated with serious human health risks. The results obtained from this study revealed that various Rhodopseudomonas palustris strains isolated from paddy soil in Taiwan possessed good HBCD biodegradation capability when they were cultured aerobically. Among these strains, YSC3 was considered as one of the most potential isolates for HBCD degradation. The optimum HBCD biodegradation occurred at neutral pH and at 35 °C in all our pH and temperature tests at an initial HBCD concentration of 1 ppm. HBCD degradation kinetics generally decreased with the increase of initial HBCD concentration. The study also suggested that the cultivation temperature played a vital role on YSC3 for its initiation of cellular HBCD degradation. The relative-molar ratio of the released bromide ions during the biodegradation of HBCD was observed in the range between 1 and 3.5, suggesting that the debromination reactions occurred. Concomitant with the loss of HBCD, there was a concurrent production of two metabolites, pentabromocyclododecanol and pentabromocyclododecene, which were determined by liquid chromatography and mass spectrometry techniques. On the basis of the obtained results, the possible biodegradation pathways were also proposed in this study. ? 2019 Elsevier Ltd
SDGs
Other Subjects
Bacteria; Biodegradation; Degradation; Health risks; Liquid chromatography; Mass spectrometry; Metabolites; Molar ratio; Nitrogen; Nitrogen fixation; Strain; Biodegradation pathways; Brominated flame retardants; Hexabromocyclododecanes; Nitrogen fixing bacteria; Persistent organic pollutant (POP); Rhodopseudomonas palustris; Sulfur bacteria; Toxic organic compounds; Organic pollutants; bromide ion; hexabromocyclododecane; brominated hydrocarbon; flame retardant; hexabromocyclododecane; pentabromocyclododecene; bacterium; biodegradation; bioremediation; bromine compound; flame retardant; methyl bromide; nitrogen fixation; organic pollutant; sulfate-reducing bacterium; aerobic metabolism; Article; bacterial strain; bacterium isolation; controlled study; debromination; degradation kinetics; liquid chromatography-mass spectrometry; metabolite; microbial degradation; nitrogen-fixing bacterium; nonhuman; pH; Rhodopseudomonas palustris; Taiwan; temperature; bioremediation; chemistry; halogenation; isolation and purification; liquid chromatography; mass spectrometry; nitrogen fixation; pathogenicity; pollutant; Rhodopseudomonas; Taiwan; Bacteria (microorganisms); Rhodopseudomonas palustris; Biodegradation, Environmental; Chromatography, Liquid; Environmental Pollutants; Flame Retardants; Halogenation; Hydrocarbons, Brominated; Hydrogen-Ion Concentration; Mass Spectrometry; Nitrogen Fixation; Rhodopseudomonas; Taiwan
Publisher
Elsevier Ltd
Type
journal article