Happy Halloween! In a perfect world, a contaminated site would contain just one type of pollutant. In reality, industrial sites are often a messy chemical soup, a mixture of solvents, petroleum products, and heavy metals all jumbled together in the same soil and groundwater. This co-contamination presents a massive challenge because the solution for one problem can be completely incompatible with the solution for another.

We've celebrated the incredible power of microbes to clean our environment, but their success hinges on a critical fact: they are living organisms. Just like us, they need a comfortable environment to survive and thrive. When the conditions at a contaminated site are too harsh, even the most heroic microbe will fail. This is the first and most common reason a bioremediation project can struggle.

Our final All-Star is a microbe that solved one of the most widespread and difficult groundwater pollution problems in the world. Meet Dehalococcoides ethenogenes, a tiny bacterium with a very big and very specific job: it is the only known organism that can fully detoxify industrial solvents like tetrachloroethylene (PCE) and trichloroethylene (TCE).