Ensayo bioluminiscencia (Aliivibrio fischeri)

Toxicity of environmental samples is an important aspect of pollution monitoring and risk assessment. Commonly employed chemical parameters for analysis are accurate and sensitive for specific molecules under investigation, but give no information regarding biological effects within the ecosystem. These methods also ignore synergistic effects from compound mixtures and can underestimate toxic potential of a sample. Evaluation of biological effects using rapid, simple and cost effective methods can provide information on whole sample effects and incorporate these important toxicity parameters into regulatory frameworks.
vibrio Fischeri Toxicity TestOne important method for assessing toxicity quickly and cost effectively is a bioluminescence inhibition assay that employs a marine gram negative bacterium, Aliivibrio fischeri (formerly Vibrio fischeri) as the test species. Light production is directly proportional to the metabolic activity of the bacterial population, and any inhibition of enzymatic activity due to toxicity or cell death causes a corresponding decrease in the bioluminescence produced by the colony. Test samples are exposed to rehydrated bacteria for a pre-determined period and the degree of light emission inhibition is compared to a negative control. In this way, the assay provides a measure of sub-lethal response as well as lethality through the degree of inhibition.
EBPI is currently carrying several preparations of high quality Aliivibrio fischeri test reagents from Finnish manufacture Aboatox to conduct rapid toxicity assessments in a wide range of environmental samples. The BioTox™ line of reagents and kits are designed to function independently and include all necessary components. The reagents and diluents can also be combined with other commercially available detector systems to produce results. Several different methodologies are available to fit project budget or laboratory setup, and can be used for analyzing various sample sizes, both clean and turbid water, and rapid determination of single tests. The reagents are standardized for use with
ISO 11348-3: Water quality – Determination of the inhibitory effect of water samples on the light emission of Vibrio fischeri (luminescent bacteria test).
ISO 21338:2010 Water quality — Kinetic determination of the inhibitory effects of sediment, other solids and coloured samples on the light emission of Vibrio fischeri (kinetic luminescent bacteria test)
The BioTox™ reagents perform comparably to several similar commercial test systems (Microtox, LumiStox, ToxAlert) when conducted according to the ISO standards mentioned above. The test organisms are extremely sensitive to organic contaminants and show excellent correlation with toxicity assessments performed with other aquatic species like the fathead minnow and Daphnia magna.