Acute copper and cupric ion toxicity in an estuarine microbial community

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Applied and Environmental Microbiology; (USA)

OSTI ID:5023837

Jonas, R B ^[1]

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1. George Mason Univ., Fairfax, VA (USA)

Copper was acutely toxic to the estuarine microbial community of Middle Marshes, N.C. Under ambient water quality conditions, 10 {mu}g of added total copper (Cu(II)) liter{sup {minus}1} reduced the CFU bacterial abundance by up to 60% and inhibited the amino acid turnover rate (AATR) by as much as 30%. Copper toxicity, however, was a quantitative function of free cupric ion (Cu{sup 2+}) activity that was not directly related to Cu(II) or ligand-bound copper. By using a nitrilotriacetic acid-cupric ion buffer to control pCu (-log Cu{sup 2+} activity), it was found that an in situ pCu of 10.1 was bactericidal, reducing the CFU by 60%, but inhibited the AATR by only about 10%. A bacterial bioassay that was used to estimate the pCu in Cu(II)-treated Middle Marshes samples indicated that less than 0.5% of added Cu(II) was in the free cupric ion form. CFU was a more sensitive indicator of low-level copper stress than was AATR. When tested at different times, native microbial community responses to acute cupric ion stress were quantitatively quite similar even when there were large differences in bacterial abundances and in situ metabolic rates. Variations were observed in response to Cu(II) treatments at different times, but these were likely due to differences in water quality, which would quantitatively influence the distribution of copper complexes that were present. Asymptotic response curves suggest that some degree of copper resistance exists in this community. At a pCu of 8, more than 2 orders of magnitude above the minimum inhibitory level, the CFU was still 5 to 10% and the AATR was about 3% of the control values.

• OSTI ID: 5023837
• Journal Information: Applied and Environmental Microbiology; (USA), Journal Name: Applied and Environmental Microbiology; (USA) Vol. 55:1; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540320 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
BACTERIA
CARBOXYLIC ACIDS
CFU
COPPER COMPOUNDS
ENVIRONMENTAL QUALITY
ESTUARIES
FEDERAL REGION IV
METABOLISM
MICROORGANISMS
NORTH AMERICA
NORTH CAROLINA
ORGANIC ACIDS
ORGANIC COMPOUNDS
SENSITIVITY
SURFACE WATERS
TOLERANCE
TOXICITY
TRANSITION ELEMENT COMPOUNDS
USA
WATER QUALITY