Bioleaching of Cadmium from Contaminated Paddy Fields by Consortium of Autotrophic and Indigenous Cadmium-Tolerant Bacteria

摘要

It has been a major issue for urgent solution in China as a result of a series of poisoning cases caused by cadmium. Yet there is no effective methods for removal of cadmium from the paddy soils. Microbial leaching process as an effective approach is currently applied to remediate the contaminated soils. In this study, bioleaching of cadmium from contaminated paddy soils by consortium of autotrophic and indigenous cadmium-tolerant bacteria was applied. The bioleaching results showed that the leaching rate of cadmium was from 74.93% to 92.76%. The distribution of the Cd fractions had a significant change before and after bioleaching with the organic fraction and residues fraction mainly remained. Moreover, the microbial community analysis showed that the Acidithiobacillus and Acidiphilium became the dominant genus in the bioleaching process. The combination of bioleaching with acidophilic chemolithotrophic microorganisms and the cadmium-resistant bacteria provides a potential process for bioremediation of metal-contaminated soils.