Abstract
O-methylation of 2,6-dibromophenol was studied in cell extracts prepared from Rhodococcus sp. strain 1395. O-methylation activity was enhanced by the addition of S-adenosyl-l-methionine but was not affected by the addition of 5-methyltetrahydrofolate nor by up to 10 mM MgCl2 or EDTA. By using 2,6-dibromophenol, 4,5,6-trichloroguaiacol, and pentachlorothiophenol as the substrates, O-methylation activity was also demonstrated in extracts from two other Rhodococcus sp. strains, an Acinetobacter sp. strain, and a Pseudomonas sp. strain. A diverse range of chloro- and bromophenols, chlorothiophenols, chloro- and bromoguaiacols, and chloro- and bromocatechols were assayed as the substrates by using extracts prepared from strain 1395; all of the compounds were methylated to the corresponding anisoles, veratroles, or guaiacols, which have been identified previously from experiments using whole cells. The specific activity of the enzyme towards the thiophenols was significantly higher than it was towards all the other substrates—high activity was found with pentafluorothiophenol, although the activity with pentafluorophenol was undetectable with the incubation times used. For the chlorophenols, the position of the substituents was of cardinal importance. The enzyme had higher activity towards the halogenated catechols than towards the corresponding guaiacols, and selective O-methylation of the 3,4,5-trihalogenocatechols yielded predominantly the 3,4,5-trihalogenoguaiacols. As in experiments with whole cells, neither 2,4-dinitrophenol, hexachlorophene, nor 5-chloro- or 5-bromovanillin was O-methylated. The results showed conclusively that the methylation reactions were enzymatic and confirmed the conclusion from extensive studies using whole cells that methylation of halogenated phenols may be a significant alternative to biodegradation.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Allard A. S., Remberger M., Neilson A. H. Bacterial O-methylation of halogen-substituted phenols. Appl Environ Microbiol. 1987 Apr;53(4):839–845. doi: 10.1128/aem.53.4.839-845.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Allard A. S., Remberger M., Neilson A. H. Bacterial o-methylation of chloroguaiacols: effect of substrate concentration, cell density, and growth conditions. Appl Environ Microbiol. 1985 Feb;49(2):279–288. doi: 10.1128/aem.49.2.279-288.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cserjesi A. J., Johnson E. L. Methylation of pentachlorophenol by Trichoderma virgatum. Can J Microbiol. 1972 Jan;18(1):45–49. doi: 10.1139/m72-007. [DOI] [PubMed] [Google Scholar]
- Drotar A. M., Fall R. Microbial methylation of benzenethiols and release of methylthiobenzenes. Experientia. 1985 Jun 15;41(6):762–764. doi: 10.1007/BF02012585. [DOI] [PubMed] [Google Scholar]
- Drotar A., Burton G. A., Jr, Tavernier J. E., Fall R. Widespread occurrence of bacterial thiol methyltransferases and the biogenic emission of methylated sulfur gases. Appl Environ Microbiol. 1987 Jul;53(7):1626–1631. doi: 10.1128/aem.53.7.1626-1631.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gee J. M., Peel J. L. Metabolism of 2,3,4,6-tetrachlorophenol by micro-organisms from broiler house litter. J Gen Microbiol. 1974 Dec;85(2):237–243. doi: 10.1099/00221287-85-2-237. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Neilson A. H., Allard A. S., Hynning P. A., Remberger M., Landner L. Bacterial methylation of chlorinated phenols and guaiacols: formation of veratroles from guaiacols and high-molecular-weight chlorinated lignin. Appl Environ Microbiol. 1983 Mar;45(3):774–783. doi: 10.1128/aem.45.3.774-783.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Veser J. Kinetics and inhibition studies of catechol O-methyltransferase from the yeast Candida tropicalis. J Bacteriol. 1987 Aug;169(8):3696–3700. doi: 10.1128/jb.169.8.3696-3700.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]