Bioavailability and toxicity of soil particle-associated copper as determined by two bioluminescent Pseudomonas fluorescens biosensor strains.

We report the development and application of a novel, solid phase-contact bioassay based on two whole-cell bacterial biosensor strains. Our data indicate that a significant fraction of particle-associated Cu may be available to bacteria in dilute soil suspensions but also support the conventional view that mainly the soluble fraction of Cu is directly available to bacteria under more realistic soil conditions.