Vibrio fischeri Microtox test

In principle, any battery of bioassays can be employed, but small-scale toxicity tests are preferred because of their performance output (Wells et al., 1998). It is highly desirable that bioassays used were part of the initial bioassay battery (prerequisite step) that proved to be sufficiently sensitive in the WASTOXHAS approach. Examples include the Microtox light inhibition test (Vibrio fischeri) and the microalgal growth inhibition assay (Selenastrum capricornutum ) that were found suitable for two tested wastes (see Section 7). 

Vibrio fischeri (Microtox light inhibition test) Escherichia coli (SOS... 

Vibrio fischeri, Microtox light inhibition test Pseudokirchneriella subcapitata, micro-algal growth inhibition assay Daphnia magna, acute immobilization test Ceriodaphnia dubia, chronic reproduction and survival test Thamnocephalus platyurus, Thamnotoxkit lethality assay. 

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

In the Microtox test, it is a standard culture of freeze-dried (lyophilized) Vibrio fischeri, stored in small, sealed vials which each contain about 100 million cells. Volume 1(1,2). 

Organisms which have been freeze-dried under vacuum (see above). Some bacteria, for example, can be lyophilized and stored for months at room temperature. They can then be rehydrated on demand and used to conduct bioassays. In the Microtox test, lyophilized Vibrio fischeri are stored in a freezer at -20° C and will be ready for use until the expiration date, which is provided with each batch of Bacterial Reagent. Volume 1(2,3). 

The Microtox test system utilizes a strain of naturally occurring luminescent bacteria - Vibrio fischeri. Exposure to a toxic substance causes a disruption of the respiratory process of the bacteria resulting in reduced light output. The effective concentration (EC50) is determined as the concentration of a toxicant that causes a 50% reduction in light output over a prescribed period of time (typically 5, 15, or 30 min). The test is fast, fairly simple to conduct, uses small sample sizes, and is relatively inexpensive. Results correlate well with those from other toxicity bioassays such as fish and Daphnia. The test is used... 

Other test methods, in which laboratories had less experience, tended to generate higher levels of variability. Interestingly, variability both within and between laboratories was smallest for a 15-min IC50 derived from the Microtox test - a rapid bioluminescence assay based on the marine bacterium Vibrio fischeri. For comparative purposes, 15-min IC50 data for 3,4-dichloroaniline are also shown in Figure 2.1. Unlike most of the other tests evaluated, the Microtox methodology... 

Vibrio fischeri (trade name Microtox ). The V.fischeri used in the Microtox tests during this study were supplied as freeze-dried batches of reagent by Azur Environmental (SDI), Hook, Hampshire, UK. These were stored at < 4°C prior... 

Backhaus T, Grimme L H. The toxicity of antibiotic agents to the luminescent bacterium Vibrio fischeri. Chemosphere 1999 38 3291-3301. Ruiz M J, Lopez-Jaramillo L, Redondo M J, Font G. Toxicity assessment of pesticides using the microtox test application to environmental samples. Bull Environ Contam Toxicol 1997 59 619-25. 

Microtox Solid-phase test SDI Vibrio fischeri is added to a suspension of the test sample. Subsequently, the mixture is filtered using the device supplied with the kit, and the light emission of the supernatant is determined. The method is a further development of the acute luminescent bacteria test for aqueous samples. Contact test with Bacillus cereus DSM No. 351 Effects on the dehydrogenase activity of the test bacterium after an exposure time of 2 hours are investigated using resazurine reduction (Ronnpagel etal. 1995). 

Research and development efforts over the last 2 years have provided new and useful infraination about the genetics and physiology of the light producing mechanism in the luminescent bacterium Vibrio fischeri. These research and development efforts, along with years of experience gained from the development and application of the Microtox Acute Toxicity Test, has resulted in the development of a new Microtox Chronic Toxicity Test System using luminescent bacteria [57]. 

The use of bioluminescence has resulted in many different tests, including the use of naturally bioluminescent bacteria (27) aside from Microtox . The genes from the bacterium Vibrio fischeri, and other bioluminescent bacteria, have been cloned into bacteriophage (15) and into plasmids that are functional in a wide range of bacterial hosts, including E. coli and strains of Pseudomonas (3,21,22,29). Many different bacterial strains have been constructed with these plasmids and produce the lux or luc (fire-fly) genes, and, therefore, light, either under constitutive expression or by some method of induction. These bioluminescent bacterial strains have been used in... 

Test based on the MA-100 microtox test, which is a standard aquatic toxicity test using the marine bacterium Vibrio fischeri. 

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