 The use of biological agents, such as bacteria or
plants, to remove or neutralize contaminants, as in
polluted soil or water.
 Any processes that uses microorganisms or their
enzymes to natural environment altered by
contaminants to its original condition.
Each year, industrial residues, domestic waste
and agricultural run-offs contaminate water, soil
and air.
 The U.S. spends millions of dollars to clean
contaminants, prevent further pollution, and
restore the site to its natural vegetative state.
 Bioremediation is
used to clean up
environmental hazards cause by
industrial toxic waste.
The contaminants are metabolized and
transformed into harmless organic and inorganic
› nitrogen, carbon dioxide and salts.
In-situ bioremediation- clean up of chemicals at
the contaminated site
Ex-situ bioremediation- removal of chemicals
from the contaminated site to another location for
The Exxon Valdez oil spill occurred in Prince William Sound,
Alaska, on March 24, 1989.
 The Exxon Valdez, an oil tanker bound for Long Beach,
California, struck Prince William Sound's Bligh Reef and
spilled 260,000 to 750,000 barrels (41,000 to 119,000 m3) of
crude oil.
 It is considered to be one of the most devastating humancaused environmental disasters.
› The Environmental Protection Agency (EPA), used
Pseudomonas developed by Ananda Chakrabarty to
degrade components in crude oil.
Exxon Valdez oil Spill
The Deepwater Horizon oil spill ( BP oil spill, the Gulf of
Mexico oil spill, the BP oil disaster or the Macondo blowout),
an oil spill in the Gulf of Mexico which flowed for three
months in 2010.
 It is the largest accidental marine oil spill in the history of the
petroleum industry.
 Scientist believes that that natural bacteria will slowly
degrade the toxic waste.
 When the influx of oil from the Deepwater Horizon leak
began, it is likely bacteria began consuming and reproducing
rapidly, breaking down oil into byproducts such as carbon
dioxide, water and other biomass.
Crude Oil Spill, Bemidji, Minnesota
• Exxon Oil spill, 1989
• Pesticides, San Francisco, Bay Estuary
• Oil release by Kuwait, 1991
Ex-Situ bioremediation requires that the
contaminated soil or water be physically
removed before treatment.
Removal of contaminants at different location
taken from the contaminated site
• More expensive and damaging to the area
• More difficult compare to In-situ bioremediation
• Examples: Sewage Treatment
A new and growing type
of bioremediation is
 Phytoremediation is the
depolluting of
contaminated soil, water
or air using plants.
It is use of plants to clean up potentially
damaging spills.
• The plants work with soil organisms to
transform contaminants, such as heavy metals
and toxic organic compounds, into harmless or
valuable forms.
Cottonwood, poplar trees and
Alpine pennycress have been used
extensively to leach heavy metals.
 Used by:
› United States Department of Agriculture
› Department of Energy (DoE)
Alpine pennycress is used
by the USDA to remove
heavy metals such as zinc
and cadmium.
Phytoremediation’s most publicize appearance came during
the Chernobyl nuclear waste cleanup in the Ukraine.
Sunflower plants were planted to remove and degrade
radioactive cesium and strontium.
Arabidopsis thaliana, a plant in the mustard family, has
two bacterial genes added to its genome in order for the
plant to remove arsenic from the soil.
 The first gene converts the arsenic to a form the plant
can suck up and the second allows the plant to detoxify
heavy metals and accumulate them in its leaves.
Polaromonas naphthalenivorans, breaks down
naphthalene in coal tar. Found in Upstate New York
and identified by the use of DNA finger printing.
 Geobacter sulfurreducens, part of a family of
bacterium that degrade metals. G. sulfurreducens
degrades uranium while G. metallireducens degrades
both uranium and plutonium.
 G. metallireducens has genes that allow it to grow
flagella and “sniff out” metals if none are available in
its location.
Thermus brockianus, produces a protein that breaks
down hydrogen peroxide.
This protein can be added directly to industrial waste
water to treat the water before it is released.
Hydrocarbon-degrading Pseudomonas strains were
transformed with an E. coli pro U operon which
improved the ability to grow under hyper-saline
conditions allowing improved bioremediation in
marine environments.
Monitored Natural way: use of pants &
Bioaugmentation: is the introduction of a group
of natural microbial strains or a genetically
engineered variant to treat contaminated soil or
Biostimulation- involves the modification of the
environment to stimulate existing bacteria
capable of bioremediation.
 This can be done by addition of various forms of
rate limiting nutrients and electron acceptors
such as phosphorus, nitrogen, oxygen, or carbon
Biobarriers : Acid rock drainage from hard rock
mine lands is a major environmental problem that
impacts both ground- and surface water throughout
the Western US.
 Naturally occurring aerobic and facultative bacteria
which utilize dissolved oxygen in the infiltrating
water and therefore maintain the reducing conditions
which are necessary for pyrite (an iron sulfide) and
other metal sulfides to remain bound in mineral form
in water.
Mycoremediation: Fungal Remediation
William J., and Michael A. Pallandino. Introduction to Biotechnology. San Francisco:
Pearson Education, Inc., 20007
“Biobarriers and Bioremediation Collection.” Montana State University Center for
Biofilm Engineering. 9 Apr. 2009, <>
“Bioremediation of metals and radionuclides.” 2nd Ed. Berkley Lab. 11 Apr. 2009.
“Recent Developments for In Situ Treatment of Metal Contaminated Soils.” U.S.
Environmental Protection Agency. 9 Apr. 2009.
“Remediation Technologies Screening Matrix and Reference Guide.” Ver. 4.0. Federal
Remediation Technologies Roundtable. 9 Apr. 2009
Singh, Harbhajan. Mycoremediation: Fungal Bioremediation. United Kingdom: WileyBlackwell, 2006
“Wet Soil Mixing.” Keller Ground Engineering. 10 Apr. 2009. <>
“Phytoremediation: Using Plants To Clean Up Soils.” June 2000. United States
Department of Agriculture. 18 Oct. 2007.
 “Sewage Treatment.” Wikipedia: The Free Encyclopedia. 19 Oct. 2007.
 Kris Traver, Niana Islam And Edwin Estime 2007 Biotech group for power point
creativity editing.
Center for Disease Control and Prevention. “Emergency Preparedness and
Response: Bioterrorism”

Chapter 9: Bioremediation - Kennesaw State University College of