Ectomycorhizal association according to fifth kingdom of biology

2. Sumaira Mustafa MS BT-16 F-17
Kiran Khalid MS BT-25 F-17
Tayyiba Khaliq MS BT-29 F-17

3.  Mycoremediation
 What is meant by eco-friendly?
 Phytoremediation: An Alternative Method for the Remediation of
 Contaminated Sites
 Compared to conventional techniques, phytoremediation has several
 advantages
 Soil Remediation with Plant-Fungal Combinations
 Technology
 Ectomycorrhizal Associations and Their Significance for
 Phytoremediation
 The Contribution of Rhizosphere and and Ectomycorrhizosphere to
 Bioremediation
 Ectomycoremediation of Heavy Metals

4. Mycoremediation:
• Mycoremediation (from ancient Greek (myco),
meaning "fungus" and the remedium,
in Latin meaning 'restoring balance') is a form
of bioremediation in which fungi-
based technology is used
to decontaminate the environment

5. In ectomycoremediation Fungi have been proven
to be a:
• Very cheap
• Effective
• Environmentally friendly
Fungi are use to remove toxins from damaged
environments.

6. The toxins include:
• Heavy metals
• Persistent organic pollutants
• Textile dyes
• Leather tanning industries
• Petroleum fuels
• Polycyclic aromatic hydrocarbon
• Pharmaceuticals and personal care products
• Pesticides and herbicide in land
• Sweet water and marine environments

7. The main inorganic pollutants are heavy
metals, such as
• cadmium,
• lead
• mercury,
• nitrates
• phosphate, and
• radio-nuclides.

8. Conventional techniques for the remediation of
polluted sites typically include:
• soil excavation,
• Ttransport,
• Washing and extraction,
• Pumping and treating of contaminated water,
• Addition of chemical reactants such as hydrogen
peroxide or potassium permanganate,
• Incineration.

9. These techniques are expensive and not always
sufficient, very invasive, and can lead to the
release of pollutants into the air or leaching into
the ground water

10. The byproducts of the remediation can be valuable
material themself, such as enzymes,edible or
medicinal mushrooms making the remediation
process even profitable.
What Does Eco-Friendly Mean?
Eco-friendly or nature-friendly, literally means earth-
friendly and are not harmful to the environment.

11. An Alternative Method for the
Remediation of Contaminated Sites:
• Phytoremediation is the direct use of living green
plants to the removal of contamination in soils:
• It is sustainable
• cost-effective

12. The following processes can be
distinguished:
• Phytostabilization
• Phytoextraction
• Phytotransformation.
• Phytovolatilization.
• Phytostimulation.

14.  It is much cheaper phytoremediation depend on site and
pollutant.
 Less secondary waste is generated, and instead a useful
product, such as wood, pulp, or bioenergy can be produced.
 It has a high public acceptance.

15.  Phytoremediation is suitable for large contaminated sites
with low-to- moderate pollutant concentration
particularly in top layers of the soil.
 polluted sites are often contaminated with a mixture of
various problematic compounds, andthe low nutrient
availability and poor soil structure

16.  This process applies to remediation and restoration of soils
contaminated by fuel and heavy meatals.
 It can be a general beneficial effect of microbial communities,
individual plant-fungus combinations can vary in their efficacy in
removal of pollutants from the environment.
 Selection of the most effective combination of plants and fungi is
very important for achieving the desired benefits.
 Not all fungi are created equal as some die off in contaminated
soils.
 Ectomycorrhizal remediation of contamination through use of
specifically adapted Soil and enzyme utilizes plant/fungal
combinations.

17.  Increased resistance to environmental extremes
 Fast response, high selectivity
 Enhances naturally occurring species ability to
decontaminate soil
 Cost effective and low maintenance
 Use of native plant/fungal combinations
 Flexibile platform

18. Plants can successfully be used for the remediation of soils
contaminated with a variety of pollutants, such as salts,
agrochemicals, nitroaromatics, chlorinated compounds, heavy
metals, and hydrocarbons

19. • Fast growing trees, such as Populus and Salix, are promising
candidates for phytoremediation or dendroremediation due to
their deep root system, and their high biomass production and
transpiration activity.
• However, the majority of tree species that have been considered
as potential candidates for phytoremediation live naturally in
symbiosis.
• Populus that has extensively been studied for its suitability in
phytoremediation also due to its accessibility for genetic
engineering forms ECM interactions with more than 60 different
fungal species, and some of these fungi have been shown to
increase the growth of poplar seedlings by more than 40%.

20.  Under natural conditions, more than 60–80% of the root
systems of poplar and willow, respectively, are colonized with
ECM fungi
 ECM fungi enhance the uptake of phosphate (P) and nitrogen
(N), and can also contribute to the supply of the host with
trace elements, such as copper (Cu) and zinc (Zn)
 Furthermore, mycorrhizal plants have a higher resistance
against abiotic (e.g., drought, heavy metals) and biotic (plant
pathogens) stresses
 the plant transfers between 10% and 20% of its
photosynthetically fixed carbon to the fungus.

21.  ECM fungi have been shown to degrade a variety of
environmentally 10 Ectomycoremediation important organic
pollutants, such as 2,4-dichlorophenol, 2,4,6-
trinitrotoluene, PCB, 4-fluorobiphenyl, and some PAHs and
the capability to degrade organic pollutants seems to be
relatively common for this group of fungi
 Meharg and Cairney (2000), for example, screened different
ECM fungal species for their capability to degrade various
classes of organic pollutants (e.g., PAHs, PCB) and found
that 33 out of 42 species were able to degrade one or more
classes of these contaminants.

22. Source:https://microbewiki.kenyon.edu/index.php/Rhizospher
e_Interactions:

23.  It is crucial to consider both, plant and fungus, as one unit,
and to assess the capability of plants and fungi to degrade
xenobiotics in the symbiotic stage to use both partners to
their full potential for the remediation of polluted sites
 This is important for the following reasons:
 Mycorrhizal fungi are ubiquitous in the soil and plants are
under natural conditions normally associated with
mycorrhizal fungi. However, the colonization with ECM fungi
can have a synergistic, but also an antagonistic effect on the
capability of the plant to remediate polluted sites.
 2. ECM roots represent the major portion of the nutrient-
absorbing surface area in tree roots and thereby also of the
root system that is potentially able to absorb and to extract
pollutants from the soil.

24.  3. The interaction of a host plant with a mycorrhizal fungus has a
much stronger impact on the whole plant physiology than
previously suggested.
 4. The symbiosis with a host plant changes the physiology of the
mycorrhizal fungus for example, affect the expression of degrading
enzymes. In the symbiosis the fungus receives carbon from its host,
and this could potentially improve the degradation rate by an
increase in the fungal biomass, but could also reduce the
degradation rate, because the more readily available substrates
are generally preferred.
 5. There is a considerable physiological diversity between
individual plant and fungal species and also between different ECM
plant/fungal associations and the potential degradation rate of
these systems is also dependent on the pollutant, its
concentration, and the environmental conditions

25.  6. It is also possible that mycorrhizal communities play a much
greater role, and that experiments with nonmycorrhizal plants or
plants that are only colonized with one ECM partner do not
reflect root systems under field conditions that are colonized on a
very small spatial scale with different taxa and species of ECM
fungi.
 7. Both symbiotic partners interact in the soil with a variety of
microorganisms, and it has been suggested that the diverse
microbial communities in the rhizosphere or mycorrhizosphere
have a much greater impact on biodegradation of organic
pollutants than the plant. the effect of the ECM system on the
activity of microbial communities in rhizosphere and
mycorrhizosphere; and the activity of both partners to degrade
pollutants in the symbiotic stage.

26. Source:https://microbewiki.kenyon.edu/index.php/Rhizospher
e_Interactions:

27.  The root rhizosphere with its stimulating effect on microbial
activities has often been described as the main contributor to
the phytoremediation of contaminated sites.

28.  (1) The direct degradation by plant-derived enzymes.
 (2) The stimulation of microbial activity and changes in
the microbial community composition due to root
exudates.
 (3) The release of metabolic precursors, for example,
phenolics, that induce the activity of enzymes that
degrade pollutants.
 (4) the establishment of environmental conditions that
stimulate degradation

29. Nutrient exchange
Source:https://microbewiki.kenyon.edu/index.php/Rhizospher
e_Interactions:

30. o Plant roots release approximately 10–20% of their
photosynthetically fixed carbon into the rhizosphere and the
secreted organic compounds, such as sugars, sugar alcohols,
amino acids, fatty acids, and proteins represent a significant
carbon source and promote microbial proliferation and
diversity in the rhizosphere
o Root exudates have also been shown to shape the microbial
community composition and its capability to degrade
recalcitrant compounds. The plant rhizosphere has also been
discussed as a potential way to introduce and to stabilize
communities of genetically engineered microorganisms in the
soil that could carry or transfer degradation genes to
indigenous microbial communities.

31.  the mycorrhizosphere represents in most soils an even larger
surface for the establishment of microbial communities than
the rhizosphere.
 The extraradical mycelium acts as an extension of the root
system and creates a large interface between hyphae and soil,
the mycorrhizosphere that can be defined as “the zone of soil
where the physical, chemical and microbiological processes are
influenced by plant roots and their associated mycorrhizal
fungi”.
 for example, that the extraradical mycelium of Pisolithus
tinctorius represents 99% of the nutrient-absorbing surface
length of pine roots.

32.  Ectomycorrhizal fungi are part of complex microbial
communities in the soil, and the interactions between the
diverse members of this community can be synergistic,
competitive, or antagonistic depending on the species and the
soil conditions.
 The presence of an ECM fungus leads to quantitative and
qualitative changes in the microbial community composition
and can result in a shift towards catabolic microbial
communities, and this could also result in changes in the
capability of these communities to degrade pollutants in the
soil.

33.  ECM roots and the extraradical mycelium are major sinks for
photosynthetically fixed carbon in mycorrhizal root systems
and it has been shown that the quantity and quality of root
exudates is altered in response to ECM colonization.
 extraradical mycelium release energy-rich compounds into the
mycorrhizosphere and can act as conduit and provide carbon
sources to heterotrophic bacterial and microbial communities
and their metabolic activities in larger distance from the root.

34.  The microbial activity in the soil near to mycorrhizal roots and
also in further distance from the root is higher than in
noncolonized root systems.
 The rhizosphere and mycorrhizosphere supported a higher
number of bacterial cells and the bacterial density was 4–5
times higher in the mycorrhizosphere than in the rhizosphere.
 The mycorrhizosphere provides an ecological niche and
nutritionally favorable conditions for diverse microbial
communities, and transmission electron microscopy of ECM
hyphae from PHC-contaminated soils revealed a microbial
biofilm at the soil/fungal interface.

35.  Plant and fungus alone were not able to degrade m-toluate,
but the bacteria with the catabolic plasmid were able to
degrade this pollutant in the mycorrhizosphere.
 The partial degradation of persistent aromatic pollutants by
ECM fungi could also provide intermediate products that can be
further broken down by microbial communities in the
mycorrhizosphere.
Source:https://microbewiki.kenyon.edu/index.php/Rhizosphere_Interactions:

36.  Heavy metals (copper, zinc, manganese, etc.) represent
a dilemma for living organisms
 They are essential, usually at low concentration, for the
structure and/or function of many cellular components
 But become toxic above threshold concentrations

37.  Mycorrhizal symbiosis has been recognized as a crucial
determinant for plant growth and productivity, and there
is mounting evidence that mycorrhizal fungi can alleviate
situations of stress in host plants, including exposure to
toxic metals

38.  The contamination of soils with the nonradioactive
metals arsenic (As),
 cadmium(Cd),
 copper (Cu),
 mercury (Hg),
 lead (Pb
 zinc (Zn) and
 the radioactive metals , uranium (U) represents a major
environmental and human health problem

39.  the utilization of mycorrhizal systems can assist
 the phytoremediation of heavy metal polluted soils by
the positive effect of ECM fungi on plant tolerance,
 but could also limit the plants ability to extract heavy
metals from the soil by reducing the uptake and the
transfer into the shoot

40.  Several mechanisms have been described to be
 involved in the reduced heavy metal uptake of ECM
plants
 the larger cell wall surface that can bind heavy metals,
 the filter function of the fungal sheath that restricts the
apoplastic movement of heavy metals into the root
cortex
 the extracellular precipitation of heavy metals,

41.  Two thousand fungal strains belonging to 98 genera of
fungi have been isolated
 from the Chernobyl Atomic Energy Station after its
nuclear accident in 1986
 Particularly ECM basidiomycetes accumulate
radionuclides in their fruitbodies, and a directed growth
would allow them to absorb radionuclides from
radioactive hotspots in the soil

42.  Metal accumulating plant species can concentrate heavy
metals like Cd, Zn, Co, Mn, Ni, and Pb up to 100 or 1000
times those taken up by nonaccumulator (excluder) plants. In
most cases, microorganisms bacteria and fungi, living in the
rhizosphere closely associated with plants, may contribute to
mobilize metal ions, increasing the bioavailable fraction