Free cyanide degradation kinetics of cyanide degrading bacteria

Abstract

This study reports on the cyanide degrading bacteria (CDB) identified from artisanal mining sites and their free cyanide (FCN) degradation kinetics in aqueous medium. CDB were isolated from soil and water samples contaminated with FCN. The CDB were mainly dominated by Pseudomonas aeruginosa, Citrabacter sp., Providencia sp. (BAB-6345), Providencia staintii (Bp-40), Citrobacter sedlakii (D5) and uncultured bacterium. . FCN removal rate by these CDB varied between 95 – 99 % during a 24h incubation at an initial FCN concentration of 60 mg CN- L -1 . The degradation kinetic studies have shown a half-saturation constant (KM), of 14 mmol CN- . L-1 for FCN and a specific activity of 28.4 mmol NH4 + formed. mol-1 CN- . min-1 . It was conclude that various CDB are available in the artisanal mining sites and the substrate FCN is well affined with the CDB activities.