Mycoremediation

Introduction

Over the last hundred years there has been a vast increase in global pollution. This pollution comes from industrial development, population growth, and a considerable disregard for the environmental consequences of releasing chemicals into the environment. There has been an overall carelessness in releasing these chemicals, whether this comes from indifference or ignorance. Because of pollution the natural environment has chemical contaminants that hare toxic to biological systems. In protecting both human health and the health of the environment, it is important to find a way to fix, or remediate, the damage that has been done due to pollutants. (Altas, Philip 2005)

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Some of the sources of pollutants

Bioremediation has been one of the traditional ways of detoxifying water and soil of pollutants. It relies on the enzymes of microorganisms, mostly bacteria, to transform or degrade the contaminants, returning the area back into its less contaminated state.(Altas, Philip 2005) In recent years a new branch of bioremediation has intrigued researchers. This is the use of fungi to detoxify contaminated soil. It’s called Mycoremediation. (Singh 2006) This is an area of science and environmental science that is making a huge impact. Maybe we can use fungi as an organic was of saving the world.
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Mycoremediation

Fungi play a big role as decomposers in our ecosystem. They affect the world at a macroscale and their impacts are mostly hidden from the world because their great mass of mycelium are found underground.(Singh 2006) Decomposition is performed by the mycelium which secrets extracellular enzymes and acids. These go on to break down long chains of carbon and hydrogen into small forms, furthering decomposition. Fungi are also very unique in the fact that they can be regenerated from both spores and hyphal fragments. (Fungi.com)

Some of the most harmful pollutants in our environments are polycyclic aromatic hydrocarbons (PAH), petroleum fuels, and PCB’s. They are toxic to both the environment and to us. PAH’s are toxins that have been known to cause cancer and developmental disorders, among other things. Fungi are being used to absorb these harmful pollutants and others like them. (Atlas, Philip 2005)

One experiment was done by Battelle research laboratory, a leader in bioremediation research. They took a plot of soil that was contaminated with diesel oil. It also reeked of aromatic hydrocarbons. They inoculated the soil with mycelia of oyster mushrooms. After four weeks more than 95% of the aromatic hydrocarbons had been reduced to non-toxic components in the mycelial-inoculated soil. What happened next was an unexpected surprise for the researchers. After 8 weeks the oyster mushrooms rotted away and attracted the flies. The flies became a attraction to other organisms and soon came the birds. The birds brought along with them seeds and the plot of soil became a life filled haven. Other plots of contaminated soil had been treated with traditional bioremediation procedures using bacteria. The plot treated with the oyster fungi was the only plot where life started to reoccur. (Thomas et al. 2000)

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Soil plot inoculated with Oyester mushrooms
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Close up of an Oyster mushroom

Soil pile inoculated with Oyster Mushrooms Close up of an Oyster Mushroom

Another similar experiment used white rot fungi to try and degrade 7 PAH in two contaminated industrial soils. Soil A was found at a tar-producing plant. Soil B was found at a wood preservation plant. Two different strains of white rot fungi were used: Irpex lacteus and Pleurotus ostreatus. Plots of soil A and B were inoculated with the two strains of white rot fungi. A control plot at each site was untreated. Plots were analyzed after 14 weeks. The results showed that I. lacteus had removed 6 out of the 7 PAH and P. ostreatus removed 5 out of the 7 PAH. What was alsoobserved was the germination of mustard seeds in the fungi treated soil plots indicating that life would return to this soil. In this experiment White rot fungi was demonstrated to be a powerful degrader of many environmental pollutants. (Bhatt et al. 2002)

There is one man who is at the lead of mycoremediation. In fact, he was the one to coin the term. His name is Paul Stamets. He has a book out called Mycelium Running: How fungi can save the world. Below is a video of a lecture he gave, talking about his research and theory of how fungi can actually save our world.






Conclusion

There has been a sizeable amount of damage that has occurred to our environment. Whether due to neglect or lack of education about our impacts on the earth, as a society we have done a lot of harm. It seems that the majority of our manufacturing and our combustion of fossil fuels continues the release of harmful toxins. As a nation, and as a world community we should be changing our current standards and looking to new ways of production, etc. As we become more aware of our actions we can look to fungi to help restore some of the damage, as we continue to look for more environmentally conscious alternatives to our everyday actions.


References

Altas, Ronald; Philip Jim. Bioremediation: applied solutions for real world environmental cleanup. 2005. ASM Press. Washington DC

Retrieved May 11, 2009 from http://www.fungi.com/mycotech/mycova.html

Thomas, S.A. 2000. "Mushrooms: Higher Macrofungi to Clean Up the Environment", Battelle Environmental Issues, Fall 2000

Singh, Harbhajan (2006). Mycoremediation: fungal bioremediation. New York: Wiley-Interscience
Bhatt,M., Cajthaml,T., Sasek,V. Mycoremediation of PAH contaminated soil. 2002. Folia Microbiologica, 3: 255-258.