Transcript Mycoremediation

• A type of Bioremediation
• Involves using mycelium
– To filter runoff water from farms, waste dumps,
junkyard sites
– To degrade toxic chemicals and destroy bacteria
and viruses in contaminated soil
– To break down garbage at dumps
• Paper and cardboard
• Diapers
• Old fuel, solvents, motor oil, paint
• Contaminates beaches, river
deltas
– Oil floats on surface of water and is
pushed onto beachfronts and into
nearby coastal swamps and
waterways
• Oil spills can happen on land
when pipelines are damaged or
oil wells leak
• Cleanup is costly and can take
years
– A ‘soup’ of petrochemicals renders
soil useless
– Toxins can continue to poison
wildlife and leech into water
Companies that produce
petrochemical-based products
have to deal with industrial waste
•
•
•
It is usually put into barrels and shipped
off-site and either buried deep in the
ground and encased in concrete or
stored above ground until it can be
incinerated
Either method of storage has significant
risks that the waste will leech into
ground water
Incinerating causes pollutants to be
released into the atmosphere
• Millions of tons of paper
and cardboard enter
landfills yearly
• More than 20 billion dirty
diapers a year enter
landfills, enough to cover a
football field three miles
deep
• Various solvents, paints,
fuels, etc. also end up in
dumps due to improper
disposal
• Landfill size is increasing
Runoff water from industrial animal
farms contains urine, feces and blood,
often from sick and/or dead animals.
It is often stored in huge open-air
waste lagoons, or manure pits.
• Harmful bacteria and viruses
contaminate rural wells, rivers, lakes and
streams
• More than 40 diseases can be
transferred to humans through manure
• Also contains high amounts of nitrates,
which can kill infants and people with
heart conditions
• Antibiotics added to feed (almost 30
million pounds a year) can lead to
antibiotic-resistant strains of bacteria
• Toxic gasses around manure pits have
asphyxiated people who got too close
Fungi play a major role in
the Earth’s environment.
•
•
•
•
Unique enzymes allow some fungi
to digest lignocellulose, giving
them a major role in the Earth’s
carbon cycle
Certain enzymes also allow some
fungi to break down complex
hydrocarbon chains found in
petrochemical pollutants
Once broken down, the nutrients
once locked up in cellulose
become available for use by
plants
Many toxic substances are broken
down into less harmful or nontoxic forms
Fungi that grow on wood are very effective at
degrading aromatic pollutants, herbicides
and pesticides—fast!
• Breaks down heavy weight hydrocarbon chains
into lighter weight molecules
• Will break down lighter hydrocarbons
completely
• Works with other microbial communities in the
soil to degrade contaminants into CO2 and water
• Oyster mushrooms can be “trained” to degrade
PCB’s, TNT, DDT and other toxins
• Were used in a project carried out by the
Washington State Transportation Commission to
clean diesel-contaminated soil from truck bays
•
•
•
Colony began mass monthly fruiting at week 4
Supported vascular plants at week 9
Declared clean enough to use on highway berms
as fill soil by week 17
Oyster mushroom mycelium “eating”
motor oil
Breaks down the strong
beta-glycoside bonds of
cellulose. The majority of
landfill space is occupied
by cellulose based waste.
• 90% of cellulose-based
products metabolized within
2 months
• Metabolized completely in 4
months
• Mushrooms are edible
Mycelium is composed of a tight network of
hyphae, thin threads that absorb liquid flowing
through them
•
•
•
•
•
Up to 8 miles of hyphae in one cubic inch of soil, some only one
cell thick
Amount of toxins that can be removed is directly related to the
size of the fungal colony
Can be used at fuel stations, farms, dump sites to filter runoff
Very cheap, simple and easy to implement-dig a hole, mix
spawn with soil, backfill hole with mixture
Highly efficient and results in much cleaner runoff within
months
Fungi have evolved to become the ultimate bio-degrader.
• Have developed enzymes that break down cellulose
– Few organisms can do this as the molecules are strongly bound
• Have developed enzymes to break down aromatic compounds
found in wood
– This property extends to toxic aromatic compounds found in crude oil,
petroleum products and byproducts
• Can absorb and destroy bacteria and viruses, filtering them out of
water that passes through the fungal colony
• Can do all these things very quickly, a matter of months in most
cases
Fungi are being investigated for use in a variety of
applications
• Replacement for Styrofoam blocks in packaging
– Waste from grain processing pressed into a mold and inoculated with
mushroom culture
– Fully colonized grain then dried under heat
– Shroom packaging fully biodegradable
• Oyster mushrooms can be “trained” to degrade specific substances
– DDT, PCB’s, TNT
– Under investigation for a variety of other toxins
• One species of oyster mushroom has been developed that can
destroy termite colonies
References