Bioremediation and Metal Resistant Bacteria in A Closed, Cold Northern Mine

摘要

Heavy metals, e.g. copper and nickel, are released to the environment as a result of mining activities. Heavy metals are required by most living organisms as trace elements, but in excess they are toxic and cause considerable environmental stress. Microbes have developed different strategies to tolerate otherwise toxic conditions. In the surroundings of closed Kotalahti Mine the concentrations of copper and nickel in the water have earlier been highly elevated. In order to decrease the concentrations of heavy metals and increase water pH, manure sludge was added to the flooded mine pit. This in situ bioreactor has operated successfully for 15 years after the treatment. The current concentrations of heavy metals are generally low. Nevertheless, resistance genes for copper (copA), cadmium-nickel (cnrA), nickel-cadmium-cobalt (nccA) and cadmiumzink (czcA) could still be found in the microbial community of the flooding water.