Das Projekt "Entwicklung und Evaluation eines Webcam Luminometers für den Leuchtbakterienhemmtest" wird vom Umweltbundesamt gefördert und von Technische Hochschule Ulm, University of Applied Sciences Labor Biotechnologie, Fakultät Mechatronik und Medizintechnik durchgeführt. Vibrio fischeri is a luminescent marine bacterium whose luminous intensity depends on the toxicity of its surroundings. By comparing light intensity before and after a certain contact time with a water sample, these bacteria can be used to detect various environmental toxins including unknown ones. A sample is considered nontoxic when the inhibition is less then 20 percent after 30min contact. In Germany, the luminescent bacteria inhibition test described in DIN EN ISO 11348 (Part 1) is a compulsory test for waste waters of industrial origin. Commercial Luminometers use Photomultiplier tubes for detection. PMTs are highly sensitive measurement devices hence the price of commercial instruments can be up to 15,000€ (including VAT). Our group has some experience with detection of low (fluorescent) light intensities by CCD cameras and webcams. In a preceding student research project we were able to prove that selected webcams are sensitive enough to detect luminescence by Vibrio fischeri in the low concentrations used in commercially available test kits. We now have developed a simple but sensitive Luminometer based on a low priced modified (black and white CCD chip and long exposure) webcam. The inhibition of various bacteria concentrations was compared to a commercial device as well as tests with actual samples. The webcam takes a picture of the light emitting test sample. The software then calculates the average luminescence of a pre defined region of interest. An additional feature is a LED for measurement of optical density which is needed to produce bacteria suspensions with standard concentrations.