Bacterial genes may help clean up common industrial solvent

An Ohio University microbiologist has isolated the genes used by a strain of bacteria to metabolise a widely-used industrial solvent which is often found in contaminated land and groundwater.

Peter Coschigano, an assistant professor of environmental microbiology, has confirmed that proteins produced from four genes found in the bacterial strain T1 are responsible for metabolising the industrial solvent toluene. Toluene is a common but toxic ingredient in gasoline, adhesives and household solvents.

Coschigano is investigating how T1 metabolises the solvent, what genes are involved and how the process is turned on and off in order to improve existing methods of cleaning up land and groundwater contaminated by the solvent.

Current cleanup techniques involve taking the contaminated soil from a site and dumping or burning it. It is thought that such expensive measures could be avoided if researchers can understand what conditions must exist for T1 to digest toluene in a contained system.

Researchers at the New York University Medical Center discovered the bacterial strain T1 about 10 years ago, digging at contaminated sites in search of an organism that could break down toluene without oxygen, which is absent in some polluted areas.

“The potential is that it can be more cost-effective and less damaging to the environment,” says Coschigano, whose research appears in the March issue of the journal Applied and Environmental Microbiology.

Coschigano tested T1 on pyruvate, a carbon substance with a significantly different structure from toluene. When the bacterial strain is grown on pyruvate, the genes responsible for metabolism don’t switch on. However, when grown on toluene, the genes work.

Proteins produced from four genes under examination are responsible for carrying out the process. Three of the proteins, which work together as a team, are activated by a fourth protein. “They are all needed to do the work,” Coschigano says. Coschigano has also detected a fifth, previously unidentified gene in the bacterium, but doesn’t know what role it plays.

Even if Coschigano determines how to control T1’s appetite for toluene in the lab, he doesn’t know how efficiently the bacterial strain will clean up contaminants in the natural environment.

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie