An algal biosensor for the monitoring of water toxicity in estuarine environments

An algal biosensor for toxicity assessment of estuarine waters is proposed. The sensor was obtained by coupling a suited algal bioreceptor (the cyanob acterium Spirulina subsalsa) to an amperometric gas diffusion electrode. Th e analytical device allows the monitoring of the evolution of photosyntheti c O-2 and the detection of alterations due to toxic effects caused by envir onmental pollutants present in the medium. Four chemical species representa tive of three main different classes of pollutants (heavy metals, triazinic herbicides, carbamate insecticides) were tested at different concentration s using a standardized natural water as experimental medium. In all the cas es a toxic response was detected (i.e. a dose-related inhibition of photosy nthetic activity was recorded) with good reproducibility. (C) 2000 Elsevier Science Ltd. hll rights reserved.