The use of intact luminous photobacteria (Vibrio fischeri and Photobacterium leiognathi) or dinoflagellates for toxicity assessment has some clear advantages that have been scientifically validated. These microorganisms are self-maintained luminescent units that under proper conditions emit high and steady levels of luminescence. The intensity of the luminescence is strongly affected by a wide range of contaminants, including pesticides, herbicides, chlorinated hydrocarbons, and heavy metals. The microorganisms work as biosensors of toxicants and by comparing the luminescence level obtained in a suspected toxic sample after a short period of incubation one can detect very low concentrations of a broad range of toxicants. A similar assessment of toxicity would be very difficult if all possible contaminants had to be determined separately.
Application Notes related to Water Toxicity Testing
Toxicity assays based on Vibrio fischeri require a sensitive. They are normally performed in tubes but can be easily adapted to microplate format.
Some regulations require the samples to be kept at 15° C. It is normally not necessary to use an instrument with cooling as measurement times are short. It is enough to keep the samples at that temperature during sample preparation and incubation.