New bacteria discovered by USU professor
Professors at Utah State University have recently discovered revolutionary bacteria that could act as a natural cleanser for contaminated soils around the world.
Ron Sims, head of the biological and irrigation engineering department, has teamed up with biology professors Anne Anderson, Charles Miller and Joanne Hughes to research the genetic makeup of five unique microbes. These bacteria, located in different parts of the United States, seem to be beneficial by naturally purifying polluted landsites.
Sims discovered three of the microbes on a Superfund site, the name given to sites the U.S. Environmental Protection Agency rates as contaminated, in Libby, Mont.
The site, an industrial wood preservative facility, had been contaminated with wood treatment fluids such as creosote, a highly toxic liquid containing mostly polycyclic aromatic hydrocarbons (PAHs), he said. PAHs are cancer-causing chemical carcinogens.
The toxic fluid had seeped deep into the soil and polluted the underground water system of a nearby town. Champion International Corporation, owner of the site, initiated bioremediation measures to clean up the soil and remove the threat to the residents.
Efforts to eliminate toxic chemicals are costly and usually result in moving the soil to a disposal site, Sims said. Until now, this option has been one of few available. The USU professors hope to provide landowners with a less expensive and more efficient option through the microbes- a way to keep their assets and not spend large and unnecessary sums of money in the process.
“The goal for me as an engineer is to do [things] faster, cheaper and better,” Sims said.
When Sims visited the Libby site, he noted that certain areas where less contaminated. He brought back a sample of the soil to Logan for testing. The bacteria were spotted on plates containing a common PAH called pyrene.
Rather than the pyrene killing the bacteria as expected, the bacteria thrived and had the ability to degrade the carcinogen. These microbes were later identified as mycobacterium isolates.
Carl Cerniglia, a colleague of Sims at the Arkansas Toxicology Center, discovered the other two isolates.
The two men collaborated with Anderson, Miller and Hughes. The Department of Energy awarded the group, led by Miller, a $1.5 million contract to sequence the mycobacterium at the DOE Joint Genome Institute in California.
The USU team will isolate the DNA from each organism and determine the size of each chromosome, which will verify how much sequencing will need to be done.
The larger the organism, the greater the amount to be sequenced. The organisms’ DNA will then be sent to California to begin the sequential process, which will take nearly one year.
When all the information is gathered, it will be returned to USU for the experts here to examine what genes and base pairs will match with other organisms in GenBank, a reserve with all the currently known gene sequences.
Some genomic sequences in the bacteria are already known. This information will make it possible to discover whether similar bacteria are located in other parts of the world by way of a “gene probe.”
The probe identifies whether or not the tested soil has DNA that matches the new mycobacteria that can degrade PAHs. If the microbes are detected, the soil can be cultivated to stimulate their growth and activity.
If the microbes are not already present in the soil, another cost effective way the professors are looking at would be to coat plant seeds with the bacteria to grow on the roots, which would spread the bacteria in the ground, USU professor Anderson said.
Tilling the microorganisms into the soil and mixing it with fertilizer is another way being considered.
“It will be useful for a lot of developing countries or countries that don’t have a lot of money for cleaning up contaminated sites,” Miller said.
The Netherlands, Poland and Russia have sites that may contain some of these same types of bacteria. Individuals in those countries are collaborating with the USU team to naturally purify these locations. The hope is that this knowledge will spread and all nations will be able to benefit.
Joop Harmsen, a senior scientist at Alterra Research Center and Wageningen University in the Netherlands, spoke with Maren Cartwright and congratulated the USU team for the project.
“PAHs have contaminated large amounts of sediment in the Netherlands, and doing this naturally through bioremediation is the most cost-effective way to treat the contaminated sediments,” Harmsen said.
-briannamo@cc.usu.edu