Mopping up sites contaminated with heavy metals is a growing concern as more and more of these areas are being discovered and designated all the time. One estimate put the number of brownfields in the U.S. at over 500,000 though heavy metals were not always the culprit. And the methods used for remediation such as introducing biological organisms to affected sites are not without their shortcomings.

As recently reported by Alex Berezow on the American Council on Science and Health's website, techniques using biotechnology are growing in popularity with researchers. One example of trying to develop genetically engineered microbes to attack heavy metals was referenced not long ago in the journal Applied Microbiology and Biotechnology.

A team of Romanian and Norwegian scientists created genes that included metal-binding peptides (similar to proteins, peptides are amino acids joined by chemical bonds). These genes were engineered with common baker's yeast, which was then tested for the ability to absorb various types of metal ions. Results showed that, based on the type of peptide used, some strains of yeast were able to take up about 80 percent of various metals including copper, manganese, cadmium, silver, cobalt and nickel.

Berezow deduces that the next steps would be to test the yeasts in real-world settings such as an actual contaminated site, and work out the most effective way of getting rid of the heavy metal infused yeast.