Cyanide is a toxic and hazardous compound for all organisms which is produced enormously by human being and causes environmental pollution. Cyanide is a natural compound produced by many organisms, including bacteria, algae, fungi, and plants, and is bio produced in some cases as a defensive metabolite or with invasive purposes. Moreover, cyanide has also been shown to be produced as part of active iron-cyanide complexes of catalytic proteins. Since cyanide is a toxic compound wellknown as a metabolic inhibitor, cyanide-containing effluents cannot be discharged without being subjected to treatment to reduce their cyanide contents to very low levels (les 0.1 mg of CN- per liter). Current chemical treatment methods are not always well adapted and efficient with regard to echnological, cost, and disposal considerations. Biodegradation is the best known method for cyanide elimination in industrial wastewater. Demands for an effective tools to estimate the risks of releasing the organic and inorganic pollutants into environment has been led to the development of very sensitive detectors of toxic substances The working theory of toxicity test system is based on intensity changes under the influence of toxic substances. Microbial degradation of cyanide in contaminated wastewater and its toxicity assay using luminescent bacterium are the purposes of the present study.
