scholarly journals Bacterial Toxicity Testing: Modification and Evaluation of the Luminescent Bacteria Test and the Respiration Inhibition Test

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1349
Author(s):  
Uwe Strotmann ◽  
Daniel Pastor Flores ◽  
Odorico Konrad ◽  
Cornelia Gendig
Keyword(s):  
Vibrio Fischeri ◽  
Toxicity Testing ◽  
Test System ◽  
Inhibition Test ◽  
Chlorinated Phenols ◽  
Bivalent Cation ◽  
Prolonged Incubation ◽  
Test Systems ◽  
Luminescent Bacteria ◽  
Luminescent Bacteria Test

The activated sludge respiration inhibition test and the luminescent bacteria test with Vibrio fischeri are important bacterial test systems for evaluation of the toxicity of chemical compounds. These test systems were further optimized to result in better handling, reliability and sensitivity. Concerning the Vibrio fischeri test, media components such as yeast extract and bivalent cation concentrations like Ca2+ and Mg2+ were optimized. The cultivation, storage conditions and reactivation process of the stored bacteria were also improved, which enabled simpler handling and led to good reproducibility. Additionally, the respiration inhibition test with a prolonged incubation time was further analyzed using different chlorinated phenols as reference compounds. It could be stated that a longer incubation period significantly improved the sensitivity of the test system.

In Vitro Toxicity Testing Using Marine Luminescent Bacteria (Photobacterium phosphoreum): the Biotox™ test

1993 ◽  
Vol 21 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Anne Kahru
Keyword(s):  
Light Output ◽  
Toxicity Testing ◽  
Test System ◽  
Photobacterium Phosphoreum ◽  
In Vitro Toxicity ◽  
Luminescent Bacteria ◽  
Time Period ◽  
Freeze Dried ◽  
Light Loss

Marine luminescent bacteria emit light naturally when they are in an optimal environment. If harmful substances are present, their bioluminescence decreases, and the amount of light loss is proportional to the toxicity. In this paper, a new short-term toxicity test system, Biotox™, based on freeze-dried Photobacterium phosphoreum, is assessed. Concentration-effect curves for 25 laboratory chemicals were measured, and EC50 values (the concentrations of chemical, μg/ml, which reduce the light output of bacteria by 50% after being in contact with bacteria over a certain time period) were calculated. The sensitivity of the Biotox™ test to hydrophilic compounds was approximately two times greater than the sensitivity of the Microtox™ test. However, the sensitivity of the Biotox™ test to hydrophobic compounds was shown to be 2–4 times lower than the sensitivity of the Microtox™ test. The Biotox™ test was especially sensitive to As5+, giving an EC50 value of 0.04μg/ml, compared with 1.5μg/ml in the Microtox™ assay.

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