After admiring the descriptions for top-down and bottom-up nanoengineering in the report, Engineered Nanoparticles; Current Knowledge about OHS [Occupational Health and Safety] Risks and Prevention Measures, (my posting of Sept. 27, 2010), I came across Michael Berger’s very interesting article about bacteria and nanoparticle factories. From Bacteria as environmentally friendly nanoparticle factories on the Nanowerk site,

“The strategy of employing recombinant E. coli expressing metal binding proteins as a nanoparticle factory is generally applicable to the combinatorial synthesis of diverse nanoparticles having a wide range of characteristics, such as optical, electronic, chemical, and magnetic properties” Sang Yup Lee, head of the Metabolic & Biomolecular Engineering National Research Laboratory at KAIST, explains to Nanowerk. “Several physico-chemical processes that have been employed for the synthesis of metal nanoparticles involve processes at high temperatures in organic solvents, which are costly and environmentally unfriendly. Nanoparticles synthesized in recombinant E. coli cells are size-tunable at ambient temperature and possess chemical and optical characteristics comparable, if not identical, to those of chemically-synthesized nanoparticles.”

If you’d asked me a few years back about using bacteria to produce metallic nanoparticles, I would have been quite wary of the idea. However, these last few years of research and thinking have led me to a more relaxed if not altogether comfortable attitude toward this kind of nanobiotechnology. In fact, I find this particular project quite interesting and hopeful.