Sodium cyanide is traditionally used in chemical me tallurgy to obtain preciousus metals (gold and silver). Cyanide produces damages because of it s toxicity and breath cell inhibition. Here we try a biotechnological process to degrade cyanide with P. fluorescens obtained by cyanide heap leaching process in gold metallurgy in Segovia, Colombia. In Colombia cyanide heap leaching process in gold metallurgy is not controlled and cyanide is used excessively. It means that great quantities of sodi um cyanide are lost in sands and in waste water. To xicity tests made by D. pulex show less than 54 ppm of cyanide is enough to kill them. Traditional treatments to cyanide degradation are useful and normal but they are expensive. Microbiological process eliminates c yanide successfully and cheap.