Luminescence inhibition

The first steps in bypassing of the biological, technological, and financial burden of live stock culturing or maintenance were made more than 20 years ago through the development of a bacterial luminescence inhibition test [34,35] this bioassay is presently known and used worldwide as the Microtox test. The revolutionary principle of this test is that it uses a lyophihzed strain of a (marine) bacterium Photobacterium phosphoreum). This makes the bioassay apphcable anytime, anywhere, without the need for continuous culturing of the test species. 

Vibrio fischeri, bacterial luminescence inhibition test or Microtox assay (DEVL34, 1998). 

Toxicity endpoint luminescence inhibition test duration 30 min. 

Italy Since 1999 toxicity assays for effluents are required by law (order D.L. 152/99). The following tests are recommended - Acute toxicity test on Daphnia magna or Ceriodaphnia dubia - Algal growth inhibition test on algae Selenastmm capricomutum - Luminescence inhibition test on bacteria - Acute toxicity test on Artemia salina (for saline discharges)... 

Fiehn, O., L. Vigelahn, G. Kalnowski, T. Reemtsma, and M. Jekel. 1997. Toxicity-directed fractionation of tannery wastewater using solid-phase extraction and luminescence inhibition in Microtiter plates. Acta Hydrochim. Hydrobiol. 25 11-16. 

This shows that the luminescence intensity decreases as a function of [Q] (Q is called a luminescence inhibitor or quencher ), in parallel to the lifetime variation no additional information is obtained by measurement of I as compared to lifetime measurements. In particular, the emission spectrum of M is not distorted (no spectral shift) when Q is added to the solution. The exact chemical nature of Z cannot be deduced from the luminescence measurement of M because the spectroscopic characteristics of Z do not appear in eqs. (15)—(18). Finally, it should be noted that, strictly speaking, the term luminescence inhibition and the Stern-Volmer equation should apply solely to experiments for which both the lifetime and the luminescence intensity decrease in parallel as a function of the concentration of a quencher . Finally, note that Stern-Volmer constants having a negative value have no physical meaning (Kessler, 1998). 

Bacterial luminescence inhibition assay on Vibrio fischeri (formerly Photobacterium phosphoreum). 

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