Nature has provided the capability to the living organisms to reduce and accumulate ions of metals during some metabolic processes when they are exposed to metal ion solutions. It is yet not clear as what proteins actually help in the generation of metal nanoparticles in the microbes except for metaloothionein and phytochelatin.

Both these compounds can bind various metals such as copper, silver, cadmium, mercury and lead to generate metal complexes. It is due to this metal binding capacity of these two proteins that has led to the research related to the production of metal nanoparticles with the help of recombinant E.coli biologically.

The metal nanoparticles generated with the help of currently employed processes have diverse characteristics such as magnetic, optical, electronic and chemical. The problem lies in the fact that the process is very cumbersome and expensive, as it requires high temperatures and organic solvents. It also adversely affects our environment. On the other hand, the nanoparticles that E.coli generates can be produced as per our requirements of size and other features. They can be synthesized at normal temperatures and possess characteristics, such as optical, electronic, magnetic etc, like the chemically produced nanoparticles. This process also scores over the current industrial process in terms of its effects on the environment.

A very important aspect of this recent development is that it can be used to produce nanoparticles of the earth metals that could not have been synthesized through chemical procedures. There are a few troubles that the researchers have faced but they believe that these petty problems can be easily sorted out.