Abstract
Chemical speciation and partitioning of radiolabeled HgCl2 were studied in model aquatic systems consisting of undisturbed eutrophic lake sediment and water in plastic cylinders. The cylinders were either gradually made anaerobic by a gentle flow of N2-CO2 or kept aerobic by air flow. The proportion of methylated 203Hg was significantly higher, in both water and sediment, in the anaerobic systems than in the aerobic systems. The composition and total concentration of fatty acids originating from bacterial phospholipids, as well as the concentration of vitamin B12, including related cobalamins, were similar in sediments from the anaerobic and aerobic systems. Bacterial cell numbers were, on average, 3.6 times higher in the anaerobic water columns than in the aerobic ones. Volatilization of 203Hg occurred in all systems except in an autoclaved control and was of similar magnitudes in the anaerobic and aerobic systems. Incorporation of 203Hg into the sediment was significantly faster in the aerobic systems than in the anaerobic systems. These results suggest that episodes of anoxia in bottom waters and sediment cause an increase in net mercury methylation and, hence, an increase in bioavailable mercury.
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Selected References
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- Alberts J. J., Schindler J. E., Miller R. W., Nutter D. E., Jr Elemental mercury evolution mediated by humic Acid. Science. 1974 May 24;184(4139):895–897. doi: 10.1126/science.184.4139.895. [DOI] [PubMed] [Google Scholar]
- BLIGH E. G., DYER W. J. A rapid method of total lipid extraction and purification. Can J Biochem Physiol. 1959 Aug;37(8):911–917. doi: 10.1139/o59-099. [DOI] [PubMed] [Google Scholar]
- Barkay T., Liebert C., Gillman M. Environmental significance of the potential for mer(Tn21)-mediated reduction of Hg2+ to Hg0 in natural waters. Appl Environ Microbiol. 1989 May;55(5):1196–1202. doi: 10.1128/aem.55.5.1196-1202.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Barkay T., Pritchard H. Adaptation of aquatic microbial communities to pollutant stress. Microbiol Sci. 1988 Jun;5(6):165–169. [PubMed] [Google Scholar]
- Beckert W. F., Moghissi A. A., Au F. H., Bretthauer E. W., McFarlane J. C. Formation of methylmercury in a terrestrial environment. Nature. 1974 Jun 14;249(458):674–675. doi: 10.1038/249674a0. [DOI] [PubMed] [Google Scholar]
- Berman M., Chase T., Bartha R. Carbon Flow in Mercury Biomethylation by Desulfovibrio desulfuricans. Appl Environ Microbiol. 1990 Jan;56(1):298–300. doi: 10.1128/aem.56.1.298-300.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bertilsson L., Neujahr H. Y. Methylation of mercury compounds by methylcobalamin. Biochemistry. 1971 Jul 6;10(14):2805–2808. doi: 10.1021/bi00790a024. [DOI] [PubMed] [Google Scholar]
- Compeau G. C., Bartha R. Effect of salinity on mercury-methylating activity of sulfate-reducing bacteria in estuarine sediments. Appl Environ Microbiol. 1987 Feb;53(2):261–265. doi: 10.1128/aem.53.2.261-265.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Compeau G. C., Bartha R. Sulfate-reducing bacteria: principal methylators of mercury in anoxic estuarine sediment. Appl Environ Microbiol. 1985 Aug;50(2):498–502. doi: 10.1128/aem.50.2.498-502.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Compeau G., Bartha R. Methylation and demethylation of mercury under controlled redox, pH and salinity conditions. Appl Environ Microbiol. 1984 Dec;48(6):1203–1207. doi: 10.1128/aem.48.6.1203-1207.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster T. J., Ginnity F. Some mercurial resistance plasmids from different incompatibility groups specify merR regulatory functions that both repress and induce the mer operon of plasmid R100. J Bacteriol. 1985 May;162(2):773–776. doi: 10.1128/jb.162.2.773-776.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Furutani A., Rudd J. W. Measurement of mercury methylation in lake water and sediment samples. Appl Environ Microbiol. 1980 Oct;40(4):770–776. doi: 10.1128/aem.40.4.770-776.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jensen S., Jernelöv A. Biological methylation of mercury in aquatic organisms. Nature. 1969 Aug 16;223(5207):753–754. doi: 10.1038/223753a0. [DOI] [PubMed] [Google Scholar]
- Osterdahl B. G., Johansson E. Comparison of two radioisotope dilution assay kits for measuring vitamin B12 in gruel. Int J Vitam Nutr Res. 1988;58(3):303–305. [PubMed] [Google Scholar]
- Osterdahl B. G., Johansson E. Radioisotope dilution determination of vitamin B12 in dietary supplements. Int J Vitam Nutr Res. 1988;58(3):300–302. [PubMed] [Google Scholar]
- Robinson J. B., Tuovinen O. H. Mechanisms of microbial resistance and detoxification of mercury and organomercury compounds: physiological, biochemical, and genetic analyses. Microbiol Rev. 1984 Jun;48(2):95–124. doi: 10.1128/mr.48.2.95-124.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schottel J., Mandal A., Clark D., Silver S., Hedges R. W. Volatilisation of mercury and organomercurials determined by inducible R-factor systems in enteric bacteria. Nature. 1974 Sep 27;251(5473):335–337. doi: 10.1038/251335a0. [DOI] [PubMed] [Google Scholar]
- Spangler W. J., Spigarelli J. L., Rose J. M., Flippin R. S., Miller H. H. Degradation of methylmercury by bacteria isolated from environmental samples. Appl Microbiol. 1973 Apr;25(4):488–493. doi: 10.1128/am.25.4.488-493.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tunlid A., Hoitink H. A., Low C., White D. C. Characterization of bacteria that suppress rhizoctonia damping-off in bark compost media by analysis of Fatty Acid biomarkers. Appl Environ Microbiol. 1989 Jun;55(6):1368–1374. doi: 10.1128/aem.55.6.1368-1374.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
