Discovered bacteria may clean contaminated soils

Monday, June 21, 2010

A SC State University environmental scientist is working to develop an application that will use recently indentified microorganisms to remediate soil containing pollutants harmful to humans and the environment.

Associate Professor of Biological Sciences Dr. Waltena Simpson, ‘91 biology, was awarded $300,000 by the 1890 Research & Extension Program at SC State to conduct the bioremediation study, which is a collaboration between the University and the Savannah River National Laboratory (SRNL).

Simpson is leading the study that will use the discovered microbes to remove or reduce the presence of polycyclic aromatic hydrocarbons (PAHs) in soil. PAHs are wide-spread environmental pollutants that form due to processing, disposal and combustion of oil products such as jet and diesel fuels, petroleum, lubricating oils and others.

PAHs pose risks to human health. For example, long-term consumption of crops grown in soil tainted with PAHs may lead to certain cancers, as the toxins are reportedly carcinogenic. The pollutants also have a drastic effect on land, rendering it unusable for cultivation.

“The microbes, classified as Sphingomonas, have the ability to break down a variety of PAHs. This holds promise for environmental scientists and agencies that are looking for eco-friendly ways to treat contaminated areas,” said Simpson.

During the first phase of the study, researchers generated stable PAH utilization mutants of  the Sphingomonas strains in an effort to identify specific genes involved in degrading PAHs. The team successfully produced several such mutants which are currently being examined.

Research will now focus on enhancing the expression of the genes to increase the rate at which the strains break down the contaminants. The enhanced strains will be tested in various sites across the state of South Carolina, if soil in those areas tests positive for presence of PAHs. SRNL will be involved in the application of the strains to PAH-containing sites.  Dr. Robin Brigmon, fellow engineer at SRNL,  will lead application efforts.

Bioremediation has had extensive success in removing harmful materials from water supplies, sewage systems, oil spills and other contaminated resources. The process is nature’s way of using microorganisms to clean up contaminants in soil or water. Adding certain fertilizers to polluted soil or water can also stimulate the process.

Simpson says if trial applications of using the microbes prove successful, use of the strains could be employed nationally, perhaps even globally, thus creating cost effective measures to reduce health hazards to humans, improve food supply and revitalize plant growth.

SC State and its 1890 Research & Extension Program, which conducts problem solving research and provides quality programs and services to improve quality of life, work extensively to develop and implement practical solutions to environmental challenges.

“As natural resources decline, we have an obligation to provide real-world solutions that will address pressing environmental issues to make our world more sustainable,” said Dr. Louis Whitesides, 1890 Research Administrator. “Research such as the bioremediation study will help us to ensure that we maintain a safe environment for generations to come.”

The study also provides support to recruit and train future scholars and practitioners in molecular and environmental science.

For more information about “Characterization and Application of Sphingomonas PAH Utilization Mutants, contact Dr. Waltena Simpson at (803) 516-4539 or To obtain information on additional studies being conducted through the 1890 Research Program, call (803) 536-8971.