Mycoremediation and Its Applications to Oil Spills

 

This week, with some of the RS team off the grid at the annual Burning Man festival in Black Rock City, Nevada, we'll be presenting highlights from the archives. The following article first ran on Reality Sandwich on May 26, 2010.

 

The BP oil spill has inflicted enormous harm in the Gulf of Mexico and will continue to do so for months, if not decades, to come. I have many thoughts on this disaster. My first reaction is that when the skin of the Earth is punctured, bad things can happen. 

Clearly, this disaster could and should have been prevented. Despite all their assurances of safety, BP and/or BP's subcontractors, failed to ensure the functionality of the emergency equipment on the Deep Horizon rig. The oil industry claims that further regulation will handcuff them, but it is now obvious that more steps need to be taken to prevent a catastrophe like this from ever happening again.

However, this spill did happen, and we now must deal with the aftermath. Although estimates have been that BP could be liable for more than 14 billion dollars in clean up damages, very few in the media have mentioned the long-term, generational consequences of this oil spill. There will inevitably be a surge in cancer cases, widespread degradation of wildlife habitat, and an array of diverse and complex strains on local communities, our nation, and the planetary ecosphere as a whole. We all know that the seas are connected, and ultimately our biosphere suffers globally when suffering locally. Now as the hurricane season approaches, we may see catastrophes converge to create what may be the greatest ecological disaster in hundreds of years. 

While we will need a wide array of efforts to address this complex problem, mycoremediation is a valuable component in our toolset of solutions. Mycoremediation has demonstrated positive results, verified by scientists in many countries. However, there is more oil spilled than there is currently mycelium available. Much more mycelium is needed and, fortunately, we know how to generate it.

Pouring oil on straw

 

Here is what we know about mycoremediation, based on tests conducted by myself, my colleagues and other researchers who have published their results. (See attached references.)

 

What we know:

1.)    More than 120 novel enzymes have been identified from mushroom-forming fungi.

2.)    Various enzymes breakdown a wide assortment of hydrocarbon toxins.

3.)    My work with Battelle Laboratories, in collaboration with their scientists, resulted in TAH's (Total Aromatic Hydrocarbons) in diesel contaminated soil to be reduced from 10,000 ppm to < 200 ppm in 16 weeks from a 25% inoculation rate of oyster (Pleurotus ostreatus) mycelium, allowing the remediated soil to be approved for use as landscaping soil along highways. (Thomas et al., 1999)

4.)    Oil contains a wide variety of toxins, many of which are carcinogens.

5.)    Mycelium more readily degrades lower molecular weight hydrocarbons (3,4,5 ring) than heavier weight hydrocarbons. However, the heavier weight hydrocarbons are reduced via mycelial enzymes into lighter weight hydrocarbons, allowing for a staged reduction with subsequent mycelial treatments.

6.)    Aged mycelium from oyster mushrooms (Pleurotus ostreatus) mixed in with ‘compost' made from woodchips and yard waste (50:50 by volume) resulted in far better degradation of hydrocarbons than oyster mushroom mycelium or compost alone.

7.)    Oyster mycelium does not degrade keratin-based hair as it produces little or no keratinases, whereas other mold fungi such as Chaetomium species (which include some high temperature-tolerant leaf mold fungi) produce keratinases.

8.)    Worms die when put into contact with high concentrations of hydrocarbon saturated soils, but live after mycelial treatments reduce the toxins below the lethal thresholds.

9.)    Spring inoculations work better than fall inoculations as the mycelium has more time to grow-out. Bioregional specificities must be carefully considered.  

10.) Amplifying native mushroom species in the bioregion impacted by toxic spills work better than non-native species.

11.) More funding is needed to better understand and implement mycoremediation technologies.

12.) Oil spills will occur in the future-we need to be ready for them!

Oyster mushrooms on oily straw

 

What we don't know:

1.)    The effect of salt water on the growth of mycelium on hair mats soaked in oil. The Presidio project with Matter of Trust did not test the hair mats used to soak up the Cosco Busan oil spill in San Francisco bay. The hair mats that were tested were ones that were put into contact with motor oil and Bunker C oil collected from the bowels of the Cosco Busan, without saltwater.

2.)    The differential gradients of decomposition of the complex oil constituents from contact with Oyster mushroom mycelium. Different toxins degrade at different rates when placed into contact with mycelium.

3.)    The variables that influence the success of mycoremediation, particularly since the targeted toxins are often complex mixtures of volatile and non-volatile hydrocarbons.

4.)    How many other species of fungi could be applied for mycoremediation beyond the few that have been tested? Up to now, Oyster mushroom mycelium (Pleurotus ostreatus) has been tested successfully but there are literally thousands of other species yet to be tested for mycoremediation.

5.)    How each fungal species used pre-selects the subsequent biological populations and how these further enable plant communities as habitats recover from toxic waste exposure.  

6.)    Whether or not the mushrooms grown on decomposing toxic wastes are safe to eat.

7.)    To what degree of decomposition by mycelium of toxic soils makes the soils safe for food crops.

8.)    How economically practical will it be to remove mushrooms that have hyper-accumulated heavy metals-will this be a viable remediation strategy? Which species are best for hyper accumulating specific metals?

9.)    How to finance/design composting centers around population centers near pollution threats?

10.) How to train-on a massive scale-the mycotechnicians needed to implement mycoremediation?

11.) How to fund "Myco-U's", learning centers with emphasis on implementing myco-solutions to human made and natural catastrophes?

12.) How extensively and diverse will mycoremediation practices be needed in the future?

Oysters on oil 

 

How can we help?

Knowing that the extent of this disaster eclipses our mycological resources should not be a reason to not act.

I proposed in 1994 that we have Mycological Response Teams (MRT's) in place to react to catastrophic events, from hurricanes to oil spills. We need to preposition composting and mycoremediation centers adjacent to population centers. We should set MRT's into motion, centralized in communities, which are actively involved in recycling, composting and permaculture-utilizing debris from natural or manmade calamities to generate enzymes and rebuild healthy local soils. 

I see the urgent need to set up webinar-like, internet based modules of education to disseminate methods for mycoremediation training so people throughout the world can benefit from the knowledge we have gained through the past decade of research.  Such hubs of learning could cross-educate others and build a body of knowledge that would be further perfected over time, benefiting from the successes and failures of those in different bioregions. The cumulative knowledge gained from a centralized data hub could emerge as a robust yet flexible platform that could help generations to come. Scientists, policy makers, and citizens would be empowered with practical mycoremediation tools for addressing environmental disasters.

There are additional opportunities here. By encouraging strategically placed gourmet mushroom production centers near debris fields from natural and human-made disasters, we can open a pathway for mycoremediation.  The ‘aged compost' that is produced after mushrooms are harvested is rich in enzymes-a value-added by-product and this ‘waste' product is aptly suited for mycoremediation purposes. What most people do not realize is that most mushroom farms generate this compost by the tons and are eager for it to be used elsewhere. 

On a grand scale, I envision that we, as a people, develop a common myco-ecology of consciousness and address these common goals through the use of mycelium. To do so means we need to spread awareness and information. Please spread the word of mycelium. Educate friends, family and policy makers about mycological solutions. Bring your local leaders up the learning curve on how fungi can decompose toxins, rebuild soils and strengthen our food chains. What we lack is the widespread availability of mycologically skilled technicians and educators and a more mycologically informed public. We need a paradigm shift, a multi-generational educational infrastructure, bringing fungal solutions to the forefront of viable options to mitigate disasters. An unfortunate circumstance we face is that the field of mycology is poorly funded in a time of intense need.

To support this expanded mycological awareness, I offer my books as resources-especially Mycelium Running: How Mushrooms Can Help Save the World and Growing Gourmet and Medicinal Mushrooms.  Also, please see my talk on Ted.com (www.ted.com/speakers/paul_stamets.html)-this is an excellent primer for those wanting to understand how mushrooms and fungi can help mitigate disasters and heal ecosystems.

Let's become part of the solution. We may not have all the answers now but we can work towards an integrated strategy, flexible in its design, and yet target specific to these types of disasters. We should work in preparation to resolve ecological emergencies before and after they occur.  Together, we can protect and heal our communities and ecosystems. 

Oysters on oil

 

THE PROBLEM: OIL IS A COMPLEX MIXTURE OF TOXIC HYDROCARBONS

Not many people, even experts, fully grasp the diverse range of toxins that are present in oil. Bunker C oil is used as a fuel, particularly in cargo ships, and is especially ‘dirty'. Here is a list of some of the hydrocarbons typically found in Bunker C oil:

CONTAMINANTS IN BUNKER C OIL

cis/trans-Decalin

C1-Fluoranthenes/Pyrenes

17a/b,21b/a 28,30-Bisnorhopane (T14a)

C1-Decalins

C2-Fluoranthenes/Pyrenes

C30 Tricyclic Terpane-22R

C2-Decalins

C3-Fluoranthenes/Pyrenes

17a(H)-22,29,30-Trisnorhopane-TM (T12)

C3-Decalins

C4-Fluoranthenes/Pyrenes

17a/b,21b/a 28,30-Bisnorhopane (T14a)

C4-Decalins

Naphthobenzothiophenes

17a(H)-22,29,30-Trisnorhopane-TM (T12)

Benzothiophene

C1-Naphthobenzothiophenes

17a(H),21b(H)-25-Norhopane (T14b)

C1-Benzo(b)thiophenes

C2-Naphthobenzothiophenes

30-Norhopane (T15)

C2-Benzo(b)thiophenes

C3-Naphthobenzothiophenes

18a(H)-30-Norneohopane-C29Ts (T16)

C3-Benzo(b)thiophenes

C4-Naphthobenzothiophenes

17a(H)-Diahopane (X)

C4-Benzo(b)thiophenes

Benz[a]anthracene

30-Normoretane (T17)

Naphthalene

Chrysene/Triphenylene

18a(H)&18b(H)-Oleananes (T18)

C1-Naphthalenes

C1-Chrysenes

Hopane (T19)

C2-Naphthalenes

C2-Chrysenes

Moretane (T20)

C3-Naphthalenes

C3-Chrysenes

30-Homohopane-22S (T21)

C4-Naphthalene

C4-Chrysenes

30-Homohopane-22R (T22)

Biphenyl

Benzo[b]fluoranthene

30,31-Bishomohopane-22S (T26)

Dibenzofuran

Benzo[k]fluoranthene

30,31-Bishomohopane-22R (T27)

Acenaphthylene

Benzo[a]fluoranthene

30,31-Trishomohopane-22S (T30)

Acenaphthene

Benzo[e]pyrene

30,31-Trishomohopane-22R (T31)

Fluorene

Benzo[a]pyrene

Tetrakishomohopane-22S (T32)

C1-Fluorenes

Perylene

Tetrakishomohopane-22R (T33)

C2-Fluorenes

Indeno[1,2,3-cd]pyrene

Pentakishomohopane-22S (T34)

C3-Fluorenes

Dibenz[a,h]anthracene

Pentakishomohopane-22R (T35)

Anthracene

Benzo[g,h,i]perylene

13b(H),17a(H)-20S-Diacholestane (S4)

Phenanthrene

C23 Tricyclic Terpane (T4)

13b(H),17a(H)-20R-Diacholestane (S5)

C1-Phenanthrenes/Anthracenes

C24 Tricyclic Terpane (T5)

13b,17a-20S-Methyldiacholestane (S8)

C2-Phenanthrenes/Anthracenes

C25 Tricyclic Terpane (T6)

14a(H),17a(H)-20S-Cholestane (S12)

C3-Phenanthrenes/Anthracenes

C24 Tetracyclic Terpane (T6a)

14a(H),17a(H)-20R-Cholestane (S17)

C4-Phenanthrenes/Anthracenes

C26 Tricyclic Terpane-22S (T6b)

13b,17a-20R-Ethyldiacholestane (S18)

Retene

C26 Tricyclic Terpane-22R (T6c)

13a,17b-20S-Ethyldiacholestane (S19)

Dibenzothiophene

C28 Tricyclic Terpane-22S (T7)

14a,17a-20S-Methylcholestane (S20)

C1-Dibenzothiophenes

C28 Tricyclic Terpane-22R (T8)

14a,17a-20R-Methylcholestane (S24)

C2-Dibenzothiophenes

C29 Tricyclic Terpane-22S (T9)

14a(H),17a(H)-20S-Ethylcholestane (S25)

C3-Dibenzothiophenes

C29 Tricyclic Terpane-22R (T10)

14a(H),17a(H)-20R-Ethylcholestane (S28)

C4-Dibenzothiophenes

18a-22,29,30-Trisnorneohopane-TS (T11)

14b(H),17b(H)-20R-Cholestane (S14)

Benzo(b)fluorene

C30 Tricyclic Terpane-22S (T11b)

14b(H),17b(H)-20S-Cholestane (S15)

Fluoranthene

C30 Tricyclic Terpane-22R

14b,17b-20R-Methylcholestane (S22)

Pyrene

17a(H)-22,29,30-Trisnorhopane-TM (T12)

14b,17b-20S-Methylcholestane

 

Oysters on oil

 

Toward an Integrated Solution: Mycomediation Resources

Recommended texts:

Gadd, G. 2001. Fungi in Bioremediation. Cambridge University Press.

Singh, H. 2006. Mycoremediation: Fungal Bioremediation.  Wiley Interscience.

Stamets, P. 2005. Mycelium Running: How Mushrooms Can Help Save the World. Ten Speed Press, Berkeley, California.

 

Recommended articles:

M. Bhatt, T. Cajthaml and V. Šašek, 2002. "Mycoremediation of PAH-contaminated soils." Folia Microbiologica, Springer Netherlands,Volume 47, Number 3 / June.

Cajthaml, T., M. Bhatt, V. Šašek, and V. Mateju. 2002. "Bioremediation of PAH-contaminated soil by composting:
A case study." Folia Microbiologica 47(6): 696-700.

Cajthaml, T., M. Moder, P. Kacer, V. Šašek, and P. Popp. 2002. "o train - on a massive scale - Study of fungal degradation products of polycyclic
aromatic hydrocarbons using gas chromatography with ion trap mass spectrometry detection. " Journal of Chromatography A, 974: 213-222.

Eggen, T., and V. Šašek. 2002. "Use of edible and medicinal oyster mushroom [Pleurotus ostreatus (Jacq.:Fr.) Kimm.] spent compost in remediation of chemically polluted soils." International Journal of MedicinalMushrooms 4: 225-261.

Giubilei, Maria A; Leonardi, Vanessa; Federici, Ermanno; Covino, Stefano; Šašek, Vaclav; Novotny, Cenek; Federici, Federico; D'Annibale, Alessandro; Petruccioli, Maurizio, 2009, June. "Effect of mobilizing agents on mycoremediation and impact on the indigenous microbiota." Journal of Chemical Technology & Biotechnology, Volume 84, Number 6, June 2009, pp. 836-844(9). John Wiley & Sons, Ltd.

Šašek, V., John A. Glaser, Philippe Baveye, 2000. "The utilization of bioremediation to reduce soil contamination: Problems and Solutions." Nato Science Series IV. Earth and Environmental Sciences vol. 19.

Šašek, V., T. Cajthaml & M. Bhatt, 2001. "Use of fungal technology in soil remediation: a case study." Water, Air and Soil Pollution: Focus 3: 5-14.

Šašek, V. 2003. "Why mycoremediations have not yet come into practice" The Utilization of Bioremediation to Reduce Soil Contamination: Problems and Solutions, 247-266. Kluwer Academic Publishers, Netherlands.

Thomas S., P. Becker, M.R. Pinza , J.Q. Word, 1999. "Mycoremediation of Aged Petroleum Hydrocarbon Contaminants in Soil." NASA no. 19990031874.

Thomas, S., 2000. Personal Communication. "Subsequently to the end of the study, WSDOT retested the soils at its own expense, with a more detailed sampling regime, and found that it did indeed meet the EPA criterion of less than or equal to 200 ppm TPH, which allowed WSDOT to use the soil in highway landscaping." Nov. 30. Email to Paul Stamets.

Oyster kit floating on water

For more information, please visit:

http://www.fungi.com/mycotech/mycova.html

http://www.fungi.com/mycotech/petroleum_problem.html

Copyright (2010) by Paul E. Stamets.

Photos of '"Oysters on Oil " are by Susan Thomas of Battelle Laboratories (Thomas et al., 1999).

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