Cyanide degradation by Pseudomonas pseudoalcaligenes strain W2 isolated from mining effluent

Abstract

Cyanide is highly toxic to the living organisms as it inhibits respiration system in the cell mitochondria. Cyanide iscommonly used in gold extraction process and its discharge into the environment not only causes pollution but it alsobrings harm to the surrounding population. Chemical treatment is expensive and the use of hazardous compound canexacerbate the problem. Biodegradation offers cheap and safe alternative as it overcomes the problems faced by chemicaltreatment. In this study, indigenous bacteria from mining wastewater were isolated. Cyanide degradation was done viashake flask method. A bacterium, designated W2 was found able to grow in the mining wastewater. 16S rRNAanalysisidentified the strain asPseudomonas pseudoalcaligeneswhich could tolerate up to 39 mg/L cyanide concentration andgrowth was depleted at 52 mg/L. 60% cyanide degradation was achieved in wastewater containing medium. End-productanalysis from high performance liquid chromatography (HPLC) detected formamide implicating the role of cyanidehydratase in cyanide degradation. It can be concluded thatP. pseudoalcaligenesis capable of biodegrading cyanideand its potential in wastewater treatment containing cyanide is feasible.