Mushrooms help with the remediation of contaminated sites
While plastics "only" pollute the environment because of their toughness, various foreign substances are extremely dangerous for nature and living beings. Polychlorinated aromatic hydrocarbons (PAH) or the explosive TNT (trinitrotoluene) poison the ecosystem and thus also have a harmful effect on people - TNT and its metabolites are, among other things, carcinogenic. Help in clearing up the contaminated sites comes from an unexpected source: fungi break down the complex chemical compounds. Eliminating the two groups of contaminated sites while at the same time preventing new ones is a task that the microbiologists at the Friedrich Schiller University in Jena have taken on very successfully. The team around Prof. Dr. Wolfgang Fritsche has succeeded in finding fungi that largely break down hazardous substances. "We are looking for fungi with new decomposition capacities in order to establish them in polluted soils in addition to the soil's own microbial flora," Fritsche explains the research approach. There are numerous problems to be solved: In the contaminated soil - for example from explosive sites or ammunition factories - there are few microorganisms that break down these hazardous substances. In addition, some of the dangerous compounds are difficult to dissolve in water and also have extremely stable molecular bonds. In addition, the microorganisms used for degradation should themselves be harmless to the environment.
After years of research, Fritsche's team found out that this can be done with a few types of mushrooms. These mushrooms can be used in many areas. The microbiologists found, among other things, white rot fungi and so-called litter decomposers, which attack and decompose polychlorinated aromatic hydrocarbons (PAH) and trinitrotoluene (TNT) and largely render their dangerous ingredients harmless. For example, the Träuschling (brown cap) edible mushroom excretes the highly active enzyme manganese peroxidase, which breaks the TNT molecular bonds. TNT is completely decomposed into carbon dioxide, water and nitrogen and is therefore harmless. This enzyme also promotes the breakdown of other environmental toxins, such as PAHs and chlorophenols, and could therefore be used to detoxify chemical waste.
In their research, the Jena scientists are primarily concerned with recognizing the mechanisms involved in degradation. This fundamental work can then make it possible to develop new remediation methods for contaminated sites and pollutants.
But in the Jena laboratories, first of all, model constructions are created, which fungi eliminate which substances. Now the team has achieved another major success: The microbiologists have developed a fungal enzyme model that attacks and decomposes the harmful content of all substances examined. The patent-pending enzymatic degradation mechanism is to be refined and further developed over the next few months in order to then prove its practical suitability in large-scale tests.
"We have proven not only in the laboratory, but also in free trials that our methods for remediation of contaminated sites work," confirms Fritsche. Even if the further marketing of the research results has not yet been clarified, "successful implementation is definitely possible", the Jena microbiologists are convinced. Therefore, the researchers may want to put their results into practice themselves and in conjunction with biotechnological companies in the Bioregio-Region Jena.