Luminescent bacteria test

ISO 11348-2 (1994) Water quality determination of the inhibitory effect of water samples on the light emission of Vibrio fischeri (luminescent bacteria test), draft, September (revised). International Organization for Standardization, Geneva... 

The toxicity requirements are established per type of industry, in terms of the maximum number of times the effluents needs to be diluted to produce a no observed effect concentration (NOEC), defined as Gf for fish, Gd for daphnia, Ga for algae, and G1 for luminescent bacteria. Testing is limited to the exposure to only the appropriate Gx level, which should not produce any observed effect [the G-value corresponds with the dilution of the effluent, expressed as the lowest dilution factor (1,2,4,...) causing less than 10% mortality]. The level of maximum allowable toxicity per industrial branch is based on the level that is considered to be attainable with state-of-the-art process and/or treatment technology. Violating the toxicity requirements results in a levy, which makes state-of-the-art compliance a more economic option [12]. 

The following example explains how a pT-value is determined. Within a dilution series, light inhibition percentages in the luminescent bacteria test at a dilution of 1 16 are below the threshold of 20 % (see Sections 5.2 and 5.4). In exponential form, 1 16 is written as 1 24 = 2A. The negative logarithm on a base of 2 of the 1 16 dilution factor is 4, or explained differently, 2 raised to the negative 4th power corresponds to 1 16. Thus, the pT-value of 4 can be attributed to the tested material. 

Inhibition values measured at 11 different time periods in an effluent from a biological wastewater treatment plant with the luminescent bacteria test are shown in Figure 1. The pT-values of this industrial wastewater discharged into the Rhine River ranged between 4 and 12 (Tab. 3). It should be noted, however, that high values were measured prior to an internal processing change in the plant and that low values were obtained after the adjustment. 

Figure 1. Inhibition values in percent measured at multiple intervals in effluents from an industrial wastewater treatment plant with the Microtox luminescent bacteria test.

When applied for characterizing the potential toxicity of wastewater effluents, the pT-method can draw attention to certain groups of chemicals in the effluent. In Section 5.7, for example, the extremely high pT-values measured with the luminescent bacteria test (pT value = 7) and the Daphnia test (pT value = 8) indicate that chemicals eliciting these toxic effects must subsequently be identified and removed in the wastewater treatment process, so as to protect decomposers and micro-crustaceans. 

Krebs, F. (1992a) Der Leuchtbakterientest fur die Wassergesetzgebung (The luminescent bacteria test for water legislation), Schriftenreihe des Vereins fur WasserBoden- und Lufthygiene 89, 591 -624. 

ISO (1998) Water quality - Determination of the inhibitory effect of water samples on light emission of Vibrio flscheri (Luminescent bacteria test), Part 3 - Method using freeze-dried bacteria. International... 

No. Location 22 Algal Test Luminescent Bacteria Test Daphnia Test Toxi- city class ... 

International Organization for Standardization (ISO) (1998) Water Quality - Determination of the Inhibitory Effect of Water Samples on the Light Emission of Vibrio fischeri (Luminescent Bacteria Test) - Parts 1-3, ISO 11348-1/3. ISO, Paris. 

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). 

Vibrio fischeri - luminescent bacteria test - acute... 

Photodegradation of the analgesic and antipyretic drug paracetamol under UV exposure at 254 nm leads to photo Fries rearrangement, affording 2-amino-5-hydro3yacetophenone. The product is more toxic than the parent drug, when examined by a luminescent bacteria test. This is... 

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