The bacteria consume naphthalene, transforming it into harmless substances and glowing as they feast. Although the bacteria can survive without naphthalene, they light up only when they are metabolizing it.
Researchers monitor the activity of the bacteria by measuring how much light they emit.
Scientists at the University of Tennessee and Oak Ridge National Laboratory combined genetic traits of three microorganisms into Psuedomonas fluorescens HK44 to create an organism that metabolizes naphthalene and emits light. Five weeks after being released, the microorganisms were still active and destroying naphthalene. Monitoring, which will continue throughout the experiment, shows there has been no interference with the existing, native organisms. Although genetically engineered plants and bacteria have been released in the past, all were released under U.S. Department of Agriculture approval. No previous release of recombinant microorganism to the environment for bioremediation had ever been approved by the Environmental Protection Agency under Toxic Substances Control Act rules.