Formation of methyl mercury by bacteria
Twenty-three Hg/sup 2 +/-resistant cultures were isolated from sediment of the Savannah River in Georgia; of these, 14 were gram-negative short rods belonging to the genera Escherichia and Enterobacter, six were gram-positive cocci (three Staphylococcus sp. and three Streptococcus sp.) and three were Bacillus sp. All the Escherichia, Enterobacter, and the Bacillus strain were more resistant to Hg/sup 2 +/ than the strains of staphylococci and streptococci. Adaptation using serial dilutions and concentration gradient agar plant techniques showed that it was possible to select a Hg/sup 2 +/-resistant strain from a parent culture identified as Enterobacter aerogenes. This culture resisted 1200 ..mu..g of Hg/sup 2 +/ per ml of medium and produced methyl mercury from HgCl/sub 2/, but was unable to convert Hg/sup 2 +/ to volatile elemental mercury (Hg/sup 0/). Under constant aeration (i.e., submerged culture), slightly more methyl mercury was formed than in the absence of aeration. Production of methyl mercury was cyclic in nature and slightly decreased if DL-homocysteine was present in media, but increased with methylcobalamine. It is concluded that the bacterial production of methyl mercury may be a means of resistance and detoxification against mercurials in which inorganic Hg/sup 2 +/ is converted to organic form and secreted into the environment. 39 references, 5 figures, 3 tables.
- Research Organization:
- Univ. of Georgia, Athens
- OSTI ID:
- 6169392
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Vol. 30:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
MERCURY
METHYLATION
BACILLUS
BIOLOGICAL ADAPTATION
BIOSYNTHESIS
ESCHERICHIA COLI
METABOLISM
METHYLMERCURY
SAVANNAH RIVER
SEDIMENTS
STAPHYLOCOCCUS
STREPTOCOCCUS
BACTERIA
CHEMICAL REACTIONS
ELEMENTS
MERCURY COMPOUNDS
METALS
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
RIVERS
STREAMS
SURFACE WATERS
SYNTHESIS
550700* - Microbiology
520200 - Environment
Aquatic- Chemicals Monitoring & Transport- (-1989)