September 12, 2017
Are probiotics the best hope for removing toxins from the air, soil and groundwater? It might seem like a reach but at least one group of researchers think that this might be the answer to improving the environment in a significant way.
For decades, multiple industries have used the solvent trichloroethylene (TCE) to do everything from clean engines to anesthetize patients in preparation for surgery. Today, the scientific community has identified this man made chemical as a toxin that does more harm than good. TCE is a known carcinogen and toxic agent responsible for causing cancer and neurological problems. Even in small amounts, exposure can produce symptoms similar to alcohol intoxication.
Unfortunately, by the time these sectors knew of the dangers presented by TCE, it had already contaminated the groundwater and soil. Researchers at the University of Washington working in conjunction with a number of small companies are looking to use poplar trees dosed with a probiotic to right this wrong.
The first report of TCE in groundwater came in 1949. Today, federal surveys acknowledge that this chemical exists in anywhere from 9 to 34 percent of drinking water sources in the U.S. The Superfund program established by the federal government works to cleanup contaminated sites from these types of pollutants. TCE represents a specific challenge, though, as the Superfund sites themselves are part of the problem. Showering at these sites releases TCE into the air as vapor.
The researchers at the University of Washington made a promising discovery. They found that a specific natural bacterial agent was effective in metabolizing TCE in poplar trees, releasing a less harmful chloride ion in the process. The scientists took this information and developed a large-scale study using a Superfund site. By placing fortified poplar trees in a Superfund area contaminated by TCE, they were able effectively to clean it up.
The study authors found that the inoculated trees increased the level of chloride ion into the soil indicating that they were indeed metabolizing the TCE pollutant. In addition, the trees carrying the probiotic showed a 32 percent increase in trunk diameter. Testing of the groundwater around the trees offered a marked decrease in the concentration of TCE levels. This upgrade to the water quickly translated into an improvement in the levels upstream of the planted area, as well.
As part of the study, they took tissue samples from the trees, too, and found evidence supporting the claim that trees inoculated with this specific Enterobacter strain were able to degrade the levels of toxic solvent in the soil and groundwater.
Environmentalists like co-author Sharon Doty with the university’s School of Environmental and Forest Science believe that this groundbreaking study is opening the door to successfully cleaning up the contaminated sites in a cost-effective way. Past solutions to removing TCE and other forms of ground toxins required excavating the earth to physically eliminate the tainted soil.
By incorporating the science of probiotics and phytoremediation – using plants to help remove toxic waste – together, they have created a new approach to eliminating carcinogenic TCE from the earth and water. This particular strain of bacteria serves as a probiotic for the tree to help it absorb the chemical from the soil and break it down into a mostly inert compound.
This is very similar to the way probiotics work for humans and animals. You ingest live organisms in a way that benefits the body. In the case of this study, the authors used the same process to benefit the host tree by allowing it to digest a substance that already exists in the ground. It is the introduction of just the right bacteria into the host organism that makes it possible.
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