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BIOTECHNOLOGY AND
ENVIRONMENT
BY
Madam Noorulnajwa Diyana Yaacob
PPK Bioproses
LECTURE 9
Chapter Contents
1.
2.
3.
4.
5.
6.
What Is Bioremediation?
Bioremediation Basics
Cleanup Sites and Strategies
Applying Genetically Engineered Strains to
Clean Up the Environment
Environmental Disasters: Case Studies in
Bioremediation
Future Strategies and Challenges for
Bioremediation
What Is Bioremediation?


Biodegradation - the use of living
organisms such as bacteria, fungi, and
plants to degrade chemical compounds
Bioremediation – process of cleaning up
environmental sites contaminated with
chemical pollutants by using living
organisms to degrade hazardous materials
into less toxic substances
What Is Bioremediation?



Initiative of the U.S. Environmental Protection
Agency (EPA)
To pollution due to chemical dumping and
storage
Purpose is to clean up hazardous waste sites
What Is Bioremediation?

Why use bioremediation?


To convert harmful pollutants into relatively
harmless materials such as carbon dioxide,
chloride, water, and simple organic molecules
Processes are generally cleaner
What Is Bioremediation?

Biotechnological approaches are essential
for;
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Detecting pollutants
Restoring ecosystems
Learning about conditions that can result in
human diseases
Converting waste products into valuable energy
Bioremediation Basics

What needs to be cleaned up?


Soil, water, air, and sediment
Pollutants enter environment in many
different ways

Tanker spill, truck accident, ruptured chemical
tank at industrial site, release of pollutants into
air
Bioremediation Basics
Bioremediation Basics

Chemicals in the Environment

Carcinogens
– Compounds that cause cancer
 Mutagens
 Cause skin rashes, birth defects
 Poison plant and animal life
Bioremediation Basics
Bioremediation Basics

Fundamentals of Cleanup Reactions

Microbes convert chemicals into harmless
substances by either


Aerobic metabolism (require oxygen) or anaerobic
metabolism (do not require oxygen)
Both processes involve oxidation and reduction
reactions

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Oxidation – removal of one or more electrons from an
atom or molecule
Reduction –addition of one or more electrons to an
atom or molecule
Bioremediation Basics
Bioremediation Basics

Aerobic and Anaerobic Biodegradation
Bioremediation Basics

Metabolizing Microbes
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Indigenous microbes – those found naturally at a
polluted site
Bacteria
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
Pseudomonas
E.coli
Algae and fungi

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Phanerochaete chrysosporium
Phanerochaete sordida
Fusarium oxysporum
Mortierella hyaline
Bioremediation Basics

Stimulating Bioremediation


Nutrient enrichment (fertilization) – fertilizers
are added to a contaminated environment to
stimulate the growth of indigenous
microorganisms that can degrade pollutants
Bioaugmentation (seeding) –bacteria are added
to the contaminated environment to assist
indigenous microbes with biodegradative
processes
Cleanup Sites and Strategies

Soil Cleanup

Ex situ bioremediation
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Slurry phase bioremediation
Solid phase bioremediation
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Composting
Land farming
Biopiles
In situ bioremediation

Bioventing – pumping either air or hydrogen peroxide into
the contaminated soil
9.3 Cleanup Sites and Strategies
Cleanup Sites and Strategies

Bioremediation of Water
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Wastewater treatment
Groundwater cleanup
Wastewater treatment
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It is a well known application of
bioremediation
The purpose is to remove;
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Human sewage
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fecal material
paper wastes
Soaps
Detergents
Other household chemicals
Wastewater treatment
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House septic systems and municipal
wastewater treatment facility use
bioremediation
Human sewage from residential house
Cleanup Sites and Strategies
Cleanup Sites and Strategies
Cleanup Sites and Strategies

Turning Wastes into Energy
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Methane gas used to produce electricity
Soil nutrients can be sold commercially as
fertilizers
Anaerobes in sediment that use organic molecules
to generate energy

Electicigens – electricity-generating microbes
Applying Genetically Engineered Strains to
Clean Up the Environment

Petroleum-Eating Bacteria
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Created in 1970s
Isolated strains of pseudomonas from
contaminated soils
Contained plasmids that encoded genes for
breaking down the pollutants
9.4 Applying Genetically Engineered
Strains to Clean Up the Environment

E. coli to clean up heavy metals
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Copper, lead, cadmium, chromium, and mercury
Biosensors – bacteria capable of detecting a
variety of environmental pollutants
Genetically Modified Plants and
Phytoremediation

Plants that can remove RDX and TNT
Environmental Disasters: Case Studies in
Bioremediation
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Jet Fuel and Hanahan, South Carolina
The Exxon Valdez Oil Spill
Oil Fields of Kuwait
Future Strategies and Challenges for
Bioremediation
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Recovering Valuable Metals
Bioremediation of Radioactive Wastes