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• Mycoremediation is the use
of fungi to degrade
pollutants from the
environment.
• Fungi have the innate
capability to breakdown
molecules, disassembling
long-chained toxins into
simpler less toxic chemicals.
• Fungi can remove heavy
metals by channeling them
into their fruitbodies.
• Mycoremediation practices
involve mixing mycelium into
contaminated soil, or placing
mycelial mats over toxic sites.
• Enzymes are secreted by
certain fungi that digest lignin
and cellulose, the primary
building blocks of wood. These
same enzymes can break down
a wide range of toxins that
have similar bonds found in
wood.
• Fungi can be broken down into
2 subgroups that pertain to
bioremediation: brown rotters
and white rotters
• White rot fungi are excellent
mycoremediators of toxins held
together by hydrogen-carbon
bonds. Enzymes secreted by white
rotters include lignin peroxidases,
manganese peroxidases, and
laccases.
• Extra-cellular lignin modifying
enzymes have very low substrate
specificity so they are able to
mineralize a wide range of highly
recalcitrant organopollutants that
are similar in structure to lignin.
• The enzymes of the lignin
degradation system of white-rot
fungi are extracellular, thus
negating the need to internalize
the pollutants and enabling the
fungi to tolerate a high
concentration of pollutants.
• White rot-fungi cannot utilize lignin
as a source of energy for growth
and instead require cosubstrates as
a carbon source.
• White rot fungi grow by hyphal
extension and thus can reach
pollutants in the soil in ways that
other organisms cannot.
• Mycelium contribute to biodiversity in nature by providing a nutrient source
for microbes aiding in the decomposing process when there is an imbalance
in the environment caused by the presence of a pollutant.
• Mycoremediated areas also provide the framework to jumpstart the
ecological restoration process.
• When selecting mushrooms for remediating a toxic site choose species that
naturally grow there first.
• Spent mushroom compost is much more biodiverse and thus more effective
than a pure culture in remediating a polluted site.
• Why is spent mushroom mycelium much more effective in
bioremediation process than a pure culture of mycelium?
• Washington State Department of Transportation in Bellingham, WA was
granted a permit to implement mycoremediation of its maintenance yard.
• 4 piles of contaminated soil were set aside on 4 sheets of 6mm black
polyethylene tarps.
• Into one pile 3 cubic yards of pure culture sawdust spawn was mixed into soil
• The spawn was sandwiched in layers within the soil.
• The other piles received no mycelia. 2 were given bacterial treatments and 1
was an untreated control.
• Approximately 4 weeks later all 3 of the piles were black and
lifeless with odor of diesel and oil while the myceliated pile
flourished with oyster mushrooms.
• Drill cuttings are mixtures of rocks and particulates released
from geologic formations in the drill holes made for crude oil
drilling.
• Spent white-rot fungi (pleurotus ostreatus) substrate was used to
treat drill cuttings in Nigeria under laboratory conditions.
• Four options of different treatment levels were tested in 10L
plastic reactors containing fixed masses of the drill cuttings
(2000g) and fresh top soil (500g) inoculated with varying
masses of the fungal substrate.
• Fungi are a versatile biosorption group as they can grow under
extreme conditions of pH, temperature and nutrient availability
as well as high metal concentration
• Biosorption is a term which involves the use of microbes to
detoxify and control environmental contaminants.
• Fungi biomasses have a high percentage of cell wall material
that show excellent metal-binding properties.
• Fungal cell wall has the key role in heavy metals sorption. The
isolated cell wall fraction accounts for 38–77% of metal uptake
and its sorption capacity was 20–50% higher than the overall
binding capacity of the mycelium.
• The heavy metal binding capacity is dependent on the mycelial
age and on the composition of culture media used for
cultivation. These phenomena are probably due to the changes
in cell wall composition.
• Inability of the fungus to compete with native microbes in soils.
Bacteria could either inhibit the growth of fungi or in
combination with fungi, enhance degradation of pollutant.
• Understanding of nutrient requirements of the fungus enabling it
to thrive at a contaminated site.
• Molecular biology including the major genes encoding lignin
peroxidases and manganese-dependent peroxidases.
• More large scale field studies to verify results of bench-scale
tests.
• Atlas RM, Bartha R (1992). Hydrocarbon biodegradation and oil spill bioremediation. Adv. Microbiol. Ecol. 12:287-
338.
• Barr BP, Aust D (1994). Mechanisms of white-rot fungi use to degrade pollutant. Environ. Sci. Technol. 28:78-87.
• Bennet JW, Wunch KG, Faison BD (2002). Use of fungi in biodegradation: of fungi in bioremediation pg. 960 -971
In: Manual of Environmental Microbiology Washington D.C.: ASM Press.
• Cerniglia CE, Sutherland JB, Crow SA (1992). Fungal metabolism of aromatic hydrocarbons. In: G.Winkelmann
(ed.) Microbial Degradation of Natural products. VCH press. Weinheim, Germany pp.193-217.
• Emuh FN (2010). Mushroom as a purifier of crude oil polluted soil. Inter. J. Sci. Nat. 1(2):127-132.
• Hamman S (2004). Bioremediation capabilities of white- rot fungi. Biodegradation 52:1-5.
• Hattaka A (1994). Lignin–modifying enzymes for selected white rot fungi production and mode in lignin degradation.
Microbiol. Rev. 13:125-135.
• Isikhuemhen OS, Anoliefo G, Oghale O (2003). Bioremediation of crude oil polluted soil by the white rot fungus,
Pleurotus tuber-regium (Fr) Sing. Environ. Sci. Pollut. Res. 10:108-112.
• Kirk TK, Lamar RT, Glaser JA (1992). Potential of white-rot fungi in bioremediation. Biotechnol. Environ. Sci. Mol.
Appl. pp. 131-138.
• Lang E, Eller I, Kleeberg R, Martens R, Zadrazil F (1995). Interaction of white rot fungi and micro-organisms
leading to biodegradation of soil pollutants. In: Proceedings of the 5th International FZK/ Tno Conference
on contaminated soil. 30th Oct- 5Nov 1995, 95:1277-1278.
• Lau KL, Tsang YY, Chiu SW (2003). Use of spent mushroom compost to bioremediate PAH- contaminated samples.
Chemosphere 52:1539-46.
• Loske D, Huttermann A, Majerczk A, Zadrazil F, Lorsen H, Waldinger P (1990). Use of white rot fungi for the clean-
up of contaminated sites. In: Coughlan MP, Collaco (eds.) Advances in biological treatment of
lignocellulosic materials. Elsevier, London pp. 311-321.
• Mansur M, Arias ME, Copa-Patino JL, Flardh M, Gonzalez AE (2003). The white–rot fungus Pleurotus ostreatus
secretes laccase isozymes with different substrate specificites. Mycologia 95(6):1013-20.
• Pointing SB (2001). Feasibility of Bioremediation by White-rot fungi. Appl. Microbiol. Biotechnol. 51:20-33.
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