Biological and chemical aspects of differences in sensitivity of natural populations of aquatic bacterial communities exposed to copper

Abstract

Bacterial populations from the main stream of the River Rhine and its plume in the North Sea, the lower course of the rivers Meuse and Scheldt, and various stagnant waters in the Netherlands were exposed to additions of copper in order to analyze differences in sensitivity. Growth rate, measured as thymidine incorporation rate, was generally more sensitive to copper (EC50: 25–310 μg · L−1) than extracellular phosphatase activity, measured as hydrolysis of methylumbelliferin phosphate (EC50: 179–3000 μgl−1). The EC50 value for copper‐inhibited growth was correlated with the ambient total copper concentration, but such a correlation was not evident for copper‐inhibited enzymatic activity. Differences in capacity of the waters to chelate an addition of 1000 μg L·−1 of copper were estimated by measuring the inhibition of Photobacterium phosphoreum in the Microtox test. The growth rate of bacteria in the upper, middle, and lower courses of the Rhine showed an increasing tolerance to copper, concurrent with increased input of copper and increasing concentrations of suspended matter in the river. It is indicated in this study that part of the differences in sensitivity of bacterial communities is caused by the chemical conditions (i.e., by complexation), but biological differences in tolerance to copper, possibly induced by pollution, were also indicated. © 1993 John Wiley & Sons, Inc.

Location‐specific ecotoxicological risk assessment of metal‐polluted soils

“…Chemical methods, like the measurements of pore-water concentrations or easily extractable fraction of metals, are not providing the solution for accurate prediction of toxic effects at polluted sites [3]. Simple pore-water concentrations are not very helpful in predicting toxic effects of metals because the presence of organic and inorganic complexes and other cations have a pronounced effect on true exposure and therefore on toxicity [4,5]. Therefore, a detailed chemical analysis is needed to predict toxic effects from pore-water concentrations.…”

A review on the ecotoxicological effects of heavy metals on aquatic organisms-siftdesk

“…The biological toxicity of heavy met-al complexes has also been reported, such as the secretion of copper and algae, copper and citric acid, and ethylenediamine complexes. Tubbing et al (1993) confirmed that regardless of how high the EDTA concentration is, a small amount of copper can cause changes in the structure and function of bacteria and algae. All these findings show that the EDTA complex copper is also toxic to bacteria and algae.…”