Based on these results, further studies with mixtures of metals will follow to elucidate preferential binding of metal ions by microorganisms. Introduction Natural resources are polluted with several kinds of heavy metals. The pollution arises as a result of human activities, largely from agriculture, industry, sewage disposal, and industrial accidents. The metals and some other contaminants tend to persist indefinitely, circulating and eventually accumulating throughout the food chain. Biotechnology, through the study of microorganisms that are capable of resisting and surviving in these polluted environments, provides the knowledge for bioremediation.
Most microorganisms have the potential to detoxify and reduce heavy metals to a non-toxic form.
This natural process, bioremediation, includes bioengineering the capabilities of intrinsic microorganisms to clean up the environment at low cost effectively. As part of the interactions between microbes and metals, microorganisms also bind metals by a physico-chemical process. This special interaction is called biosorption. Microorganisms act as living barriers and immobilize toxic metals by binding them to their cell wall. The initial mechanism for metal binding is electrostatic attraction between ions and charged functional groups of the microbial cell wall.