Environmental Biotechnology, Bioremediation

1. Environmental Biotechnology,
Bioremediation

2. Introduction
 Environmental
biotechnology is biotechnology that is
applied to and used to study the natural
environment.
 Environmental biotechnology is the solving
of environmental problems through the
application of biotechnology.
 Environmental biotechnology is a system
of scientific and engineering knowledge
related to the use of microorganisms and
their products in the prevention of
environmental pollution through
biotreatment of solid, liquid, and gaseous
wastes, bioremediation of polluted
environments, and biomonitoring of
environment and treatment processes.

3. Importance of environmental
biotechnology
 It is needed to:
 eliminate the hazardous wastes produced
by our other technologies.
 distinguish between similar species and
ensure species are not at risk of extinction.
 create alternative energy sources (i.e.
Biofuel).

4. Composition of a Desktop
Computer

5. Pollution….
 Pollution is the introduction of contaminants into the
natural environment that cause adverse change.
 Pollutants, the components of pollution

6. Environmental
Biotechnology
Key intervention points of environmental
biotechnology

7. Bio-
treatment/Bioremediation
 Bioremediation is the use of micro-organism metabolism to
remove pollutants
 These methods are almost typical “end-of-pipe processes” applied to
remove, degrade, or detoxify pollution in environmental

8. Ways of Bioremediation
 Removal/ separation: a process that removes the
contaminant from the host medium
 Destruction/degradation: a process that chemically or
biologically destroys or neutralizes the contaminant to
produce less toxic compounds
 Containment/immobilization: a process that impedes
or immobilizes the surface and subsurface migration
of the contaminant

9. Microorganisms and processes
 Bacteria:
 (Aerobic bacteria: Pseudomonas, Alcaligenes, Sphingomonas, Rhodococcus,
Mycobacterium)
 degrade pesticides and hydrocarbons, both alkanes and poly-aromatic
compounds
 bacteria use the contaminant as the sole source of carbon and energy
 it is a faster process
 anaerobic bacteria are used for bioremediation of polychlorinated biphenyls
(PCBs) in river sediments, de-chlorination of the solvent trichloroethylene
(TCE), chloroform
 Ligninolytic fungi:
 have the ability to degrade an extremely diverse range of persistent or toxic
environmental pollutants (as white rot fungus Phanaerochaete
chrysosporium)
 Methylotrophs
 grow utilizing methane for carbon and energy
 are active against a wide range of compounds, including the chlorinated
aliphatics trichloroethylene and 1,2-dichloroethane DDT

10. Factors Influencing
Bioremediation

11. Chromium (VI) from Leather
Tanneries
 Chromium is a toxic heavy metal that is widely used in
electroplating, leather tanning, textile dyeing, and metal processing
industries.
 European Union recommends total chromium limits of 0.05 and
0.1 mg/L for potable and industrial wastewater respectively
 Many microorganisms have been reported to reduce the highly
soluble and toxic Cr(VI) to the less soluble and less toxic Cr(III), e.g.,
Acinetobacter, Arthrobacter, Pseudomonas sp.

12. Phytoremediation

13. Methods of
phytoremediation
 Phytoextraction or phytoaccumulation
 the plants accumulate contaminants into the roots and aboveground shoots
or leaves
 produces a mass of plants and contaminants (usually metals) that can be
transported for disposal or recycling
 Phytotransformation or phytodegradation
 uptake of organic contaminants from soil, sediments, or water and,
subsequently, their transformation to more stable, less toxic, or less mobile
form
 Phytostabilization
 plants reduce the mobility and migration of contaminated soil
 leachable constituents are adsorbed and bound into the plant structure so
that they form a stable mass of plant from which the contaminants will not
reenter the environment

14. Methods of
phytoremediation
 Phytodegradation or rhizodegradation
 breakdown of contaminants through the activity existing in the
rhizosphere, due to the presence of proteins and enzymes produced by
the plants or by soil organisms such as bacteria, yeast, and fungi
 is a symbiotic relationship that has evolved between plants and microbes:
plants provide nutrients necessary for the microbes to thrive, while
 microbes provide a healthier soil environment
 Rhizofiltration
 is a water remediation technique that involves the uptake of
contaminants by plant roots
 is used to reduce contamination in natural wetlands and estuary area
 Phytovolatilization
 plants evaportranspirate selenium, mercury, and volatile hydrocarbons
from soils and groundwater

15. Phytoremediation

16. Bioremediation Background
 Natural Attenuation is Not fast enough, Not
complete enough, Not frequently
occurring enough to be broadly used for
some compounds, especially chlorinated
solvents
 The current trend is to stimulate/enhance a
site’s indigenous subsurface microorganisms
by the addition of nutrients and electron
donor
 In some cases, bioaugmentation is necessary
when metabolic capabilities are not naturally
present.

17. Historical Perspective
 ~1900 Advent of biological processes to treat organics derived
from human or animal wastes (and the sludges produced)
 ~1950 Approaches to extend wastewater treatment to industrial
wastes
 ~1960 Investigations into the bioremediation of synthetic
chemicals in wastewaters
 ~1970 Application in hydrocarbon contamination such as oil
spills and petroleum in groundwater
 ~1980 Investigations of bioremediation applications for
substituted organics
 ~1990 Natural Attenuation of ’70 and ’90, and the development
of barrier approaches
 ~2000 High-rate in situ bioremediation; source zone reduction;
bioaugmentation

18. Soil and Subsurface
Contaminants
 Benzene and related fuel components (BTEX)
 Pyrene and other polynuclear aromatics
 Chlorinated aromatics and solvents
 Herbicides and pesticides
 Nitroaromatic explosives and plasticizers

19. Sources of Contamination
 Industrial spills and
leaks
 Surface impoundments
 Storage tanks and pipes
 Landfills
 Burial areas and dumps
 Injection wells
Confining
Unit
Water table
Saline
Water
Lateral
intrusion of
saline water
Ocean
Municipal
water well
Abandoned
oil well
Deep
Aquifer
pond
Infiltration of
pesticides and
fertilizers from
farmlands
Brine leakage from
ruptured well casing
septic tank
leakage
Fresh
water
Accidental
fuel spill
Municipal
landfill
Leakage from
hazardous
waste site
Contaminated
shallow
well
Leaking
petroleum
tank
Confining
Unit

20. Current Water Issues Associated
with Gasoline Use
 Widespread contamination
 Major treat to drinking water resources
 Components of fuels are known carcinogens
 Current fuel oxygenate, MTBE, very mobile and not very
degradable
 Ethanol is due to replace MTBE, but its behavior in the
subsurface is not yet understood

21. What is Bioremediation
 Using subsurface microorganisms to
transform hazardous contaminants into
relatively harmless byproducts, such as
ethene and water
 Biodegrade
 Mineralize
 Biotransform
 Techniques or types of bioremediation:
 A component of Natural Attenuation
 Enhanced Bioremediation
 Bioaugmentation

22.  Bioremediation is a triple-corners process:
Organisms
Pollutants
Environments
Microorganisms
Plants
Enzymes
Soil
Water
Air
Organic
Inorganic
Solid
Liquid
Gas

23. Bioremediation related topics
Biosurfactants
Bioremediation
techniques
Environments
Organisms
Phytoremediation
Bioremediation of
metals polluted
environment
Enzymes separation
and identification
Cells immobilization
Pollutants
Bioremediation
Enzymes
immobilization

24. Stages of a biodegradation study
1- Isolation of the microorganism
5- Determination of the biodegradation
efficiency
4- Optimization of the biodegradation
conditions
3- Identification of the microbial isolate
2- Purification of the obtained isolates
6- Identification of the biodegradation products.
7- Cell or enzyme immobilization.
8- Enzyme identification.

25. Phytoremediation
 Phytoremediation is use of plants for accumulation,
removal or conversion of pollutants.
Phytoremediation
Phytostabilization
Phytotransformation Phytoextraction
Phytovolatilization Phytostimulation

26.  Approximately 400 plant species have been classified as
hyperaccumulators of heavy metals, such as grasses,
sunflower, corn, hemp, flax, alfalfa, tobacco, willow, Indian
mustard, poplar, water hyacinth, etc.

27.  The root exudates of these plants play an
important role in phytoremediation as it
activate the surrounded microorganisms.
 Genetic engineering are used as in case of
BT protein or insect pheromones
producing plants to reduce the use of
pesticides.

28. Metals bioremediation
mechanisms
Solubilization
(Bioleaching)
Complexation
(Bioaccomulation)
(Biosorption)
Metal
immobilization
Precipitation
- H2S producing bacteria
- Siderophores.
- Metal reduction.
- Exopolysaccharide.
- Lipoproteins.
- Organic acids.
- Siderophores.
- Root exudates.

29.  The biosurfactants are chemical compounds
characterized by hydrophobic and hydrophilic (non-
polar and polar) regions in one molecule
(amphipathic molecules).
 Biosurfactants from bacteria, cyanobacteria, fungi
and yeast are classified into:
1) Glycolipids.
2) Lipopeptides.
3) Phospholipids.
4) Glycoproteins.
5) Polymeric biosurfactants.
Biosurfactants

30. Physiological roles of biosurfactants:
1- Increase the availability of hydrophobic compounds
2- Nutrient storage molecules.
3- Save the microbial cells from toxic substances.
4- Efflux of harmful compounds.
5- Extracellular and intracellular interactions such as quorum
sensing and biofilm.

31. Biosurfactant applications in
bioremediation:
 The microbe may access a poorly water-
soluble substrate that has been
“pseudosolubilized” by the biosurfactant.
 Reduce the adsorption of the non-polar
pollutants to the surface of soil particles.

32. Bioremediation techniques:
(1) In-situ (without excavation).
(2) Ex-situ (with excavation).
Only ex-situ processes allow an efficient optimization of
incubation parameters (biostimulation), including:
pH,
Aeration,
Agitation,
Moistening
nutrients,
solvents or surfactants.
In addition to addition of microorganisms (bioaugmentation).

33.  The ex-situ technique includes:
1- Bioslurry reactor.
2- Biopile.
3- landfarming
Bioslurry reactor.
Biopile.
Biopile.