Researchers have developed and field-tested a new technique that identifies specific soil microbes that can break down environmental pollutants. The bacteria could be used to clean up toxic-waste sites.
Eugene Madsen of Cornell University and his colleagues tested their technique at a coal tar waste site associated with an old gasworks. The researchers labeled a test sample of naphthalene–a common, seemingly benign coal tar component–with the isotope carbon-13 and released the chemical into the soil. The researchers then covered patches of soil with 250-milliliter glass jars. If a plot harbored soil bacteria capable of metabolizing the naphthalene, carbon dioxide that included carbon-13 built up in the jar over that soil.