It's a basic knowledge about Biotransformation of heavy metal impact of heavy metals Type of impact of heavy metals

1. BIOTRANSFORMATION
OF HEAVY METALS
SUBJECT : BIOREMEDIATION
VIVEKANANDHA ARTS AND SCIENCE COLLEGE
FOR WOMEN,
VEERACHIALAYAM,SANKAGIRI,SALEM,TAMILNADU.
DEPARTMENT OF MICROBILOGY
SUMMITED BY
S.PUNITHA,
I,ST M.SC MICROBIOLOGY,
VIVEKANAANDHA ARTS AND SCIENCE COLLEGE
FORWOMEN,
VEERACHIPALAYAM,SANKAGIRI,SALEM,TAMILNADU
GUIDED BY
DR. R. DINESH KUMAR
ASSISTANT PROFESSOR,
DEPARTMENT OF MICROBIOLOGY,
VIVEKANANDHA ARTS AND SCIENCE COLLEGE FOR WOMEN,
VEERACHIPALYAM,SANKAGIRI,SALEM,TAMILNADU

2. BIOTRANSFORMATION
INTRODUCTION:
 Biotransformation is the process by which organic
compound are transferred from one to another to reduce
the presistence and toxicity of the chemical compound.
 This process is aided by major range of microorganisms
and their products such as Bacteria,fungi and Enzyme.
 This mechanism has been developed by microbes to
acclimatize to environmental changes and it is useful in
the wide range of biotechnology process.

3. CONTINUOUS :
 Environmental protection is an important factor in
ensuring the function and balanced ecosystem .
 A number of environmental pollutants cause by high level
degradation impact on ecosystem components especially
soil.
 An excess in the required concentration results in heavy
metals pollution or contamination.
 Heavy metals chemical refers to class a distinct
subdivision of elements characterized with metallic
properties.

4. CONTINUOUS :
 The availability or entry of heavy metals into the
ecosystem originate from diverse sources either natural or
anthropongies.
 Significant source includes geological weathering,
minerals exploration,soil erosion, industrial discharge,
agriculture use of chemicals for pest or disease control and
other factors.

5. IMPACT OF HEAVY METAL
IMPACT OF SOIL :
 Soil is the maroj sink of heavy metalsdue to its various
anthropologie activities.Heavy metals alter the
composition and activity of soil microbial
communities.
 High concentration of heavy metal in the soil results
in high soil toxicity.
 The enzyme activity in heavy metal contaminated soil
is reduced significantly compared with their in non
contaminated soil.Heavy metal may persist in soil for
a considerably long time.

6. CONTINUOUS:
 Heavy metal include exchangeable ions thar are absorbed by
inorganic solids in the surface.
 Insoluble inorganic and nonexchange ions compounds,such as
carbonate and phosphate are compounds from soluble metals ,
organic metal complexes and metals attached to silicates
minerals.
 Metals induces toxic effects on soil microbes,and the degree of
impact varies due to physicochemical condition,such as PH,
temperature,clay minerals, abundance of organic matters,
inorganic anion and cation and chemical forms of the metal They
also reduce organic decomposition in the soil and nutrients
recycling.

7. Fig : Impact of soil in heavy metals.

8. IMPACT OF PLANTS :
 Heavy metal accumulation above the tolerance level in
plants also induces adverse effects on the plants.The plant
becomes remarkably toxic and it may ultimately die.
 Hence some plants tolerate metal toxicity untill the
threshold level.
 Two aspects of plants heavy metal intaraction are as
follows:
 I)Metal induced impairment of plant development.
 II)Resistive adaptation of plants to metal toxicity
through modified metabolism.

9. CONTINUOUS:
 Heavy metal can Interfere with the biological and
physiological processes that are crucial to plants growth.A
contaminated plant may exhibit reduced yield
production,which consequently affects the food chain.
 Cytoplasmic enzyme inhibition and cell structure damage
due to oxidative stress occur when the plant is
contaminated with a heavy metals
 An example of an indirect toxic effects is the replacement
of essential nutrients at the cation exchange sites of plant.

10. CONTINUOUS:
 The water content of Brassica juncea plants remarkably
decrease under Pb toxicity, although this species is
considered tolerant.
 The plant exposed to heavy metal exhibiti stunted growth,
deformation, reduced physicochemical activities and
overall alternations of cellular metabolism.
 Their measurements also revealed that heavy metals affect
the growth and photosynthesis pigments of the plants.

11. Fig : Impact of plant in heavy metals.

12. IMPACT ON HUMAN HEALTH :
 Heavy metals contamination in the environment can
directly affect humans through dust inhalation or skin
absorption.
 Heavy metals contamination in soil poses a threat to both
humans and ecosystem through direct ingestion or contact
with contaminated soil.
 In the food chain, toxicity occurs in the following order
 Soil > Plant > Animals > Human.

13. CONTINUOUS:
 Heavy metals contamination in soil also affect human health
through drinking of contaminated groundwater and
consumption of contaminated plants,this contamination also
induces reduced agricultural production.
 Heavy metals exposure occur through water,fish,soil,food
crops,food animals and toys.
 This exposure the metal toxicity in children to damage the
organ and boby system.
 Cd emission have increased remarkably in recent years,
especially with its presence in household waste.

14. Fig: Impact of human health in heavy metals.

15. PHYTOREMEDIATION OF HEAVY METALS
:
 Phytoremediation utilizes a variety of plants process and
the physical characteristics of plant to aid in remediation
of contaminated sites.
 Remediation of metals using plants seems an effective
approach in the present scenario since plants are the
primary recipient of heavy metals.
 Phytoremediation technique includes:
 I)Phytoextraction.
 II)Phytostabilization.
 III)Phytovolatilization.

16. PHYTOEXTRACTION:
 It is the process of uptake of contaminants from soil or
water by plant root and their accumulation in biomass
i,e..shoots.
 A recent study suggested that the highly developed root
system of Napier grass makes it an ideal candidate for
Phytoextraction process by absorbing, transporting and
storing both contaminants and nutrients into the plant
tissue.

17. Fig: Phytoextraction

18. PHYTOSTABILIZATION :
 Phytostabilization is a method where the plants are used to
immobilise metals in the rhizosphere
 There are two main factors:
I)Root accumulation.
II) Rhizosphere in mobilization
 Giant reed (Arundo donax)and silvergrass(Miscanthus
Sinensis) genotypes are bioenergy crops well suited for
the Phytostabilization of metaloid contamination of dry
land

19. Fig : Phytostabilization

20. PHYTOVOLATILIZATION:
 This approach involves conversion of heavy metals into
volatile forms by plants and subsequently released into the
atmosphere.This process has been used for removal of
some volatile heavy metals like Hg and Se from polluted
soils.
Fig : Phytovolatilization

21. MECHANISM OF HEAVY METALS
PHYTOREMEDIATION :
 The uptake of heavy metals by plants depends mainly on
the bioavailability of the heavy metal in the soil as well as
the plant nutrients.
 The heavy metals either gets accumulated in the root
tissues or get translocated to the aerial region of the plants
through xylem vessels by symplastic or apoplastic
pathways.

22. Fig : Phtoremediation of heavy metals

23. CASE PRACTICE IN
PHYTOREMEDIATION
Removal of heavy metals from wetlands:
 Wetlands are important sinks for heavy metals and they
can exert toxic effects on Biotransformation
 Wetlands are affected rapidly because of growing
urbanization coupled with industrialization.In developing
countries, industrialization occurs through the replacement
of natural ecosystem,with the main objective of
commodity production for a short term benefit.
 The potential of water hyacinth to translocate metals in
order of Zn<Ni<Cd<Ni<Zn.

24. CONTINUOUS:
 Water hyacinth present bioconcentration abilities when
planted in aquatic environment with low concentration of
the selected metals.
 The plants root accumulate metal concentration that are
more than 3-15times higher than concentration
accumulation in shoots.
 Hence the order of absorption in terms of concentration at
the roots of the plants is Cu>Zn>Ni>Pb>Cd.
 The water hyacinth phytoremediation to remove Cd,Cu,Pb
and Zn from wastewater.

25. REMOVAL OF HEAVY METALS FROM
AGRICULTURAL SOILS:
 Metal pollution in Taiwan paddy soils is the significant
problem that involves illegal disposal of wastewater from
industries, mainly chemical and electroplate plants, rather
than only metals from parent material.
 An important example is the extent of Cd contamination
induced by plastic stabilizer that is used to produce rice in
Taoyuon.
 The contaminated areas was mostly polluted with
Cr,Cu,Ni and Zn.In this site's Twelve plant species were
used to growing the contaminated site within the first 31
days.

26. CONTINUOUS :
 Plants root tend to accumulate higher concentration of
heavy metals than those of the shoot.The phytoavailability
of soil metals decrease with time during
Phytoextraction,which increases the period required for
effective remediation.
 The also used to suitable plants contaminated with high
concentration of heavy metals enable the contaminated
sites to recover to their natural condition and generate
economic benefits.

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