Biotoxicity of mercury as influenced by mercury(II) speciation. [Pseudomonas fluorescens]

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Applied and Environmental Microbiology; (United States)

OSTI ID:5317237

Farrell, R E; Germida, J J; Ming Huang, P ^[1]

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1. Univ. of Saskatchewan, Saskatoon (Canada)

Integration of physicochemical procedures for studying mercury(II) speciation with microbiological procedures for studying the effects of mercury on bacterial growth allows evaluation of ionic factors (e.g., pH and ligand species and concentration) which affect biotoxicity. A Pseudomonas fluorescens strain capable of methylating inorganic Hg(II) was isolated from sediment samples collected at Buffalo Pound Lake in Saskatchewan, Canada. The effect of pH and ligand species on the toxic response (i.e., 50% inhibitory concentration (IC{sub 50})) of the P. fluorescens isolate to mercury were determined and related to the aqueous speciation of Hg(II). It was determined that the toxicities of different mercury salts were influenced by the nature of the co-ion. At a given pH level, mercuric acetate and mercuric nitrate yielded essentially the same IC{sub 50} s; mercuric chloride, on the other hand, always produced lower IC{sub 50}s. For each Hg salt, toxicity was greatest at pH 6.0 and decreased significantly at pH 7.0. Increasing the pH to 8.0 had no effect on the toxicity of mercuric acetate or mercuric nitrate but significantly reduced the toxicity of mercuric chloride. The aqueous speciation of Hg(II) in the synthetic growth medium M-IIY (a minimal salts medium amended to contain 0.1% yeast extract and 0.1% glycerol) was calculated by using the computer program GEOCHEM-PC with a modified data base.

• OSTI ID: 5317237
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 56:10; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540310 -- Environment
Aquatic-- Basic Studies-- (1990-)
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACETATES
BACTERIA
BIOGEOCHEMISTRY
BIOLOGICAL AVAILABILITY
CARBOXYLIC ACID SALTS
CHEMICAL REACTIONS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
COMPARATIVE EVALUATIONS
COMPUTER CODES
ELEMENTS
EVALUATION
G CODES
GEOCHEMISTRY
HALIDES
HALOGEN COMPOUNDS
MERCURY
MERCURY COMPOUNDS
METALS
METHYLATION
METHYLMERCURY
MICROORGANISMS
NITRATES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
OXYGEN COMPOUNDS
PH VALUE
PSEUDOMONAS
SEDIMENTS
SENSITIVITY
TOXICITY
WATER CHEMISTRY