Bacterial O-methylation of halogen-substituted phenols

Abstract

Two strains of bacteria capable of carrying out the 0-methylation of phenolic compounds, one from the gram-positive genus Rhodococcus and one from the gram-negative genus Acinetobacter, were used to examine the 0-methylation of phenols carrying fluoro-, chloro-, and bromo-substituents. Zero-order rates of 0methylation were calculated from data for the chloroand bromophenols; there was no simple relationship between the rates of reaction and the structure of the substrates, and significant differences were observed in the responses of the two test organisms. For the gram-negative strain, the pattern of substitution was as important as the number of substituents. Hexachlorophene was resistant to 0-methylation by both strains, and tetrabromobisphenol-A was 0-methylated only by the gram-positive strain. It is suggested that in the natural environment, bacterial 0-methylation of phenols carrying electron-attracting substituents might be a significant alternative to biodegradation.

Microbial breakdown of halogenated aromatic pesticides and related compounds

“…Several species of Gram-positive and Gramnegative bacteria belonging to the genera Acinetobacter, Pseudomonas, Mycobacterium, and Rhodococcus have been shown to O-methylate chlorinated phenols and chlorophenol derivatives [104,[106][107][108][109][110][111][112]. O-Methylation of chlorophenols to the corresponding chloroanisoles has also frequently been observed with different species of fungi [71,[113][114][115][116][117].…”

Biodegradation and Metabolism of Tetrabromobisphenol A (TBBPA) in the Bioaugmented Activated Sludge Batch Bioreactor System by Heterotrophic and Nitrifying Bacteria

“…Microbial biotransformation of organic compounds normally takes place through species specific attack to the active site of the target molecule by adding, substituting or modifying a functional group in the structure (Tamm, 1974;Allard et al, 1987;George and Haggblom, 2008). The ring cleavage or the reductive debromination is also mediated by the microbial activity (Ronen and Abeliovich, 2000;Zhang et al, 2013).…”

Biodegradation of 2,4,6‐TCA by the white‐rot fungus Phlebia radiata is initiated by a phase I (O‐demethylation)–phase II (O‐conjugation) reactions system: implications for the chlorine cycle

“…Chemically, they are very stable compounds. Therefore, they are more resistant to biodegradation than chlorophenols, being highly persistent in the ecosystems (Allard et al, 1987).…”

“…O-methylation of chlorophenols is therefore a way to remove chlorophenols from the ecosystems in aerobic conditions. This reaction is really a detoxification process which transforms the highly toxic chlorophenols into non-toxic chloroanisoles (Cserjesi and Johnson, 1972;Allard et al, 1987;Neilson et al, 1988;Álvarez-Rodríguez et al, 2002). The capability to produce chloroanisoles is well documented in fungi.…”

“…A fungal S-adenosyl-L-methionine (SAM)-dependent chlorophenol O-methyltransferase (CPOMT), which is able to methylate a wide range of chloro-, bromo-and iodophenols to form the corresponding anisoles has been characterized (Coque et al, 2003). Also, it has been reported the capability of several bacterial strains to carry out the O-methylation of chlorophenols (Allard et al, 1987;Neilson et al, 1988;Nystrom et al, 1992), although the overall contribution of these bacterial strains to the chloroanisoles levels in the environment seems to be of minor importance.…”