The historic use of chlordecone (C 10 Cl 10 O) as a pesticide to control banana weevil infestations has resulted in pollution of large land areas in the French West Indies. Although currently banned, chlordecone persists because it adsorbs strongly to soil and its complex bishomocubane structure is stable, particularly under aerobic conditions. Abiotic chemical transformation catalyzed by reduced vitamin B 12 has been shown to break down chlordecone by opening the cage structure to produce C9 polychloroindenes. More recently these C9 polychloroindenes were also observed as products of anaerobic microbiological transformation. To investigate the anaerobic biotransformation of chlordecone by microbes native to the French West Indies, microcosms were constructed anaerobically from chlordecone impacted Guadeloupe soil and sludge to mimic natural attenuation and eletron donor-stimulated reductive dechlorination. Original microcosms and transfers were incubated over a period of 8 years, during which they were repeatedly amended with chlordecone and electron donor (ethanol and acetone). Using LC-MS, chlordecone and degradation products were detected in all the biologically active microcosms. Observed products included monohydro-, dihydro-and trihydrochlordecone derivatives (C 10 Cl 10-n O 2 H n ; n = 1,2,3), as well as "open cage" C9 polychloroindene compounds (C 9 Cl 5-n H 3+n n = 0,1,2) and C10 carboxylated polychloroindene derivatives (C 10 Cl 4-n O 2 H 4+n , n = 0-3). Products with as many as 9 chlorine atoms removed were detected. These products were not observed in sterile (poisoned) microcosms. Chlordecone concentrations decreased in active microcosms as concentrations of products increased, indicating that anaerobic dechlorination processes have occurred. The data enabled a crude estimation of partitioning coefficients between soil and water, showing that carboxylated intermediates sorb poorly and as a consequence may be flushed away, while polychlorinated indenes sorb strongly to soil. Microbial community analysis in microcosms revealed enrichment of anaerobic fermenting and acetogenic microbes possibly involved in anaerobic chlordecone biotransformation. It thus should be possible to
Anaerobic microcosms constructed with soil from Guadeloupe, amended with ethanol and acetone and incubated anaerobically for more than a decade, transformed chlordecone (CLD) into a suite of progressively more dechlorinated products, including a fully dechlorinated carboxylated indene product. This fully dechlorinated transformation product has never before been observed and indicates that complete dechlorination of CLD is possible. The carboxylated indene was detected by LC-MS, and structure was confirmed by LC-MS/MS using a Q-Exactive Orbitrap mass spectrometer.
Anaerobic microcosms constructed with soil from Guadeloupe, amended with electron donor (ethanol and acetone) and incubated for more than a decade, transformed chlordecone (CLD) into a suite of progressively more dechlorinated products, including a fully dechlorinated carboxylated indene product. This fully dechlorinated transformation product has never before been observed and indicates that complete dechlorination of CLD is possible. The carboxylated indene was detected by LC-MS and structure was confirmed by LC-MS/MS using a Q-Exactive Orbitrap mass spectrometer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.