BIOLOGICAL CYANIDE DESTRUCTION MEDIATED BY MICROORGANISMS

Many microorganisms have an inherent capacity to degrade the toxic org anic compounds that enter the environment as a result of pollution and natural activities. Significant degradation of these compounds may ta ke many years and it is frequently necessary to consider methods that can accelerate this process. There have been several demonstrations of enhanced biological degradation, of toxic wastes, both in the laborat ory and under field conditions. The prospects for enhanced biological cyanide degradation are reviewed. Compared with bench-scale processes, there are very few reports of field-scale processes for cyanide biore mediation. The implementation of such field-scale degradation requires inputs from biology, hydrology, geology, chemistry and civil engineer ing. A conceptual framework is emerging that can be adapted to develop new processes for bioremediation of toxic organic wastes. In terms of cyanide biodegradation, this framework incorporates identification of microbes, determination of the optimal conditions for degradation, es tablishment of the metabolic pathways involved in cyanide degradation, identification and localization of the genes involved, identification of suitable microbial strains for practical application and developme nt of practical engineering processes. The present review addresses th e progress that has been made in each of these aspects of cyanide biod egradation. IL also examines the existing field applications of biolog ical cyanide degradation and makes recommendations for future research .