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Investigations of enzymatic alterations of 2,4-dichlorophenol using 13C-nuclear magnetic resonance combination with site-specific 13C-labeling: understanding the environmental fate of this pollutant

Author:
Nanny, M.A., Bortiatynski, J.M., Tien, M., Hatcher, P.G.
Source:
Environmental toxicology and chemistry 1996 v.15 no.11 pp. 1857-1864
ISSN:
0730-7268
Subject:
2,4-dichlorophenol, Phanerochaete chrysosporium, alkanes, biodegradation, byproducts, environmental fate, ethers, microbial biomass, nuclear magnetic resonance spectroscopy, organic matter, sodium hydroxide, white-rot fungi
Abstract:
The biodegradation of 13C-labeled 2,4-dichlorophenol (DCP labeled at the C-2 and C-6 positions), in the presence and absence of natural organic matter (NOM), by the white-rot fungus Phanerochaete chrysosporium, was examined using 13C-nuclear magnetic resonance (NMR). Using this method permitted the chemistry occurring at or near the labeled site to be followed. The formation of alkyl ethers and alkene ethers was observed. No aromatic by-products were detected, indicating that aromatic compounds are quickly degraded. Examining the reaction with time shows the exponential removal of 2,4-DCP and the consequential formation of labeled by-products, whose concentration reaches a maximum just before all 2,4-DCP is consumed. After this, the by-products degrade exponentially. The presence of NOM causes 2,4-DCP to be removed from the aqueous phase more quickly than in its absence and also causes the by-products to reach their maximum concentration much earlier. Degradation of the by-products occurs at a much greater rate in the presence of NOM. One hypothesis for this behavior is that the NOM interacts with 2,4-DCP and its by-products, allowing them to be incorporated into the fungal biomass. 13C-nuclear magnetic resonance spectra of the fungal biomass after NaOH extraction show the presence of alkanes and a small amount of 2,4-DCP.
Agid:
1968113