Most cyanide-containing industrial effluents also contain other cyano-derivatives and high amounts of metals and metal–cyanide compounds. pseudoalcaligenes CECT5344, isolated after an enrichment cultivation procedure, has the ability to use cyanide as the sole nitrogen source under alkaline conditions that avoid hydrogen cyanide volatilization.

Despite the toxicity of cyanide, cyanotrophic microorganisms such as the alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 may use cyanide and its derivatives as a nitrogen source for growth, making biodegradation of cyanurated industrial waste possible. Thus, cyanide biodegradation has become an efficient economically interesting alternative to the physical-chemical treatments of cyanide-containing industrial residues. Conventional chemical treatments of cyanide wastewaters can be effective at reducing the toxicity from cyanide they can be costly, require significant infrastructure, need long-term storage or transportation, and involve reagents that pose their own environmental hazards. These mining practices generate large volumes of cyanide-laden effluent, which when not properly contained and remediated, have had catastrophic impacts on downstream environments and human communities. Up to 90% of gold is extracted from ore utilizing some form of cyanide leaching. The use that created the largest environmental threat of cyanide is as a lixiviant in gold leach mining. The global consumption of cyanide is over 1.5 million metric tons per year. The toxicity of cyanide arises from its affinity for metals and the inhibition of cytochrome C oxidase in the electron transport chain as well as many other metalloenzymes by binding metal ions critical to the proteins’ functions. As consequence, cyanide-containing wastes are accumulated in the environment becoming a risk to human health and ecosystems. Cyanide leaching remains the only viable chemical lixivant for the recovery of gold, accounting for 90% of world production. In gold and silver mining, cyanide is used to recover these metals through the leaching process. The Cyanide, one of the known most toxic chemicals, is widely used in several industries including plastics, electroplating, organic chemicals production, photographic developing, and pharmaceuticals.

Cyanide poisoning kit