Bioremediation

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Bioremediation
Chapter 9
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Biotechnology and the Environment

• Environment describes everything that surrounds
  a particular organism
• Other organisms
• Soil, air, water
• Temperature, humidity, radiation

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Biotechnology and the Environment

• Environmental Biotechnology -
• the development, use and regulation of
• biological systems for remediation of
• contaminated environments (land, air,
• water), and for environment-friendly
• processes.
• Bioremediation - the use of
• microorganisms to remedy
• environmental problems

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Biotechnology and the Environment

• What are the events that triggered the interest
  in environmental biotechnology?
• Rachel Carlsons Silent Spring (DDT)
• Love Canal
• Burning of a River
• Exxon Valdez in 1989

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Biotechnology and the Environment

• What do they all have in common?
• The advent of the Industrial Revolution
• increase in products and waste
• people moved to the city
• increase in human population

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Biotechnology and the Environment

• Regulations were passed
• Resource Conservation and Recovery Act (1976)
• Must identify hazardous waste and establish
  standards for managing it properly
• Requires companies that store, treat or dispose
  to have permits stating how the wastes are to be
  managed
• Record of its travels Chain of Custody
• EPA initiates the Superfund Program (1980)
• Counteract careless and negligent practices
• Environmental Genome Project
• Study and understand the impacts of environmental
  chemicals on human diseases

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Biotechnology and the Environment

• Waste
• Solid landfills, combustion-including waste-to
  energy plants, recovery
• slurries, composting
• Liquid septic sewage treatment, deep-well
  injection
• Gas fossil fuels, chlorofluorocarbons
• Hazardous anything that can explode, catch fire,
  release toxic fumes, and particles or cause
  corrosion

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Garbage Test
Biotechnology and the Environment

• Banana Peel
• Wood Scrap/Sawdust
• Wax Paper
• Styrofoam Cup
• Tin Can
• Aluminum Soda Can
• Plastic Carton
• Glass Bottles

• 0.5 Years
• 4 Years
• 5 Years
• 20 Years
• 100 Years
• 500 Years
• 500 Years
• gt500 Years

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There is no waste in Nature

• From rocks and soil to plants and animals to air
  and water and back again

Recycled largely by Microbes
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Biogeochemical Cycles are a major part of the
recycling process

• Carbon Cycle The primary biogeochemical cycle
  organic cmpds ? CO2 and back
• Nitrogen Cycle proteins? amino acids?
  NH3?NO2-?NO3-?NO2-?N2O?N2 ?NH3 etc_
• Sulfur Cycle Just like the nitrogen cycle,
  numerous oxidation states. Modeled in the
  Winogradsky column
• Phosphorous Cycle Doesnt cycle between numerous
  oxidation states only soluble and insoluble form

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Carbon Cycle
CO2
Organic compounds
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Nitrogen Cycle
cyanobacteria
N2
leguminous
decomposition
Fixation
ammonification
NH3
NO2-
nitrosomas
Nitrification
Pseudomonas Bacillus Paracoccus
NO2-
Denitrification
nitrobacter
NO3-
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Sulfur Cycle
Atmosphere
SO2
H2SO4
Organic sulfur S SO4 H2S
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Phosphorus Cycle
Phosphates too complex for plants to absorb from
the soil
Sea simple Phosphates Phosphate rocks
Microbes Breakdown complex compounds
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Biotechnology and the Environment

• Scientists learn from nature in the 1980s
• The concept of Gaia the total world is a living
  organism and what nature makes nature can degrade
  (bioinfalibility) only man makes xenobiotic
  compounds
• Clean up pollution-short and long term solutions
  (cost, toxicity, time frame)
• Use compounds that are biodegradable
• Produce Energy and Materials in less destructive
  ways
• Monitor Environmental Health
• Increase Recovery of Minerals and Oil

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Biotechnology and the Environment

• Bioremediation finds its place
• Companies begin to specialize in cleaning up
  toxic waste spills by using a mixture of bacteria
  and fungi because cleaning these spills usually
  requires the combined efforts of several strains.
• Biotechnologists begin engineering super bugs
  to clean up wastes.
• However, there are many microorganisms in nature
  that will degrade waste products.

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Bioremediation Basics

• Naturally occurring marshes and wetlands have
  been doing the job!
• What Needs to be Cleaned UP?
• Everything!
• How do pollutants enter the environment?
• Runoff, leachates, air
• SO How bioremediation is used depends on
• what is contaminated? (locations)
• on the types of chemicals that need to be cleaned
  up
• the concentration of the contaminants (amount and
  duration)

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Bioremediation Basics

• Chemicals in the environment
• Sewage (by products of medicines and food we eat
  such as estrogen (birth control pills) and
  caffeine (coffee)
• Products around the house (perfumes, fertilizers,
  pesticides, medicines)
• Industrial
• Agricultural

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Bioremediation Basics
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Bioremediation Basics

• Fundamentals of Cleanup Reactions
• Microbes can convert many chemicals into harmless
  compounds HOW?
• Aerobic or anaerobically
• Both involve oxidation and reduction reactions

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Bioremediation Basics

• Fundamentals of Cleanup Reactions
• Oxidation and Reduction Reactions
• Oxidation involves the removal of one or more
  electrons
• Reduction involves the addition of one or more
  electrons
• Oxidizing agents gain electrons and reducing
  agents lose electrons
• The rxns are usually coupled and the paired rxns
  are known are redox reactions

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Bioremediation Basics

• Example
• Na Cl2 ? NaCl

reduced
0
0
1
-1
oxidized
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Bioremediation Basics

• Aerobic and anaerobic biodegradation
• Aerobic
• Oxygen is reduced to water and the organic
  molecules (e.g. petroleum, sugar) are oxidized
• Anaerobic
• An inorganic compound is reduced and the organic
  molecules are oxidized (e.g. nitrate is reduced
  and sugar is oxidized)
• NOTE Many microbes can do both aerobic and
  anaerobic respiration the process which produces
  the most ATP is used first!

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Bioremediation Basics

• The Players Metabolizing Microbes
• Site usually contains a variety of microbes
• Closest to the contaminant anaerobes
• Farthest away aerobes
• The most common and effective bacteria are the
  indigenous microbes (e.g. Pseudomonas in soil)
• Fungus and algae are also present in the
  environment and do a good job of cleaning up
  chemicals (fungi do it better than bacteria)

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Bioremediation Basics

• Bioremediation Genomics Programs
• Stimulating Bioremediation
• Add fertilizers (nutrient enrichment) to
  stimulate the
• growth of indigenous microorganisms
• Adding bacteria or fungus to assist
  indigenous
• microbes is known as bioaugumentation or
  seeding

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Bioremediation Basics

• Phytomediation
• Utilizing plants to clean up chemicals
• Ex cottonwoods, poplar, juniper trees, grasses,
  alfalfa
• Low cost, low maintenance and it adds beauty to
  the site

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Cleanup Sites and Strategies

• Do the chemicals pose a fire or explosive hazard?
• Do the chemicals pose a threat to human health
  including the health of clean-up workers? (what
  happened at Chernobyl to the workers?)
• Was the chemical released into the environment
  through a single incident or was there long-term
  leakage from a storage container?
• Where did the contamination occur?
• Is the contaminated area at the surface of the
  soil? Below ground? Does it affect water?
• How large is the contaminated area?

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Cleanup Sites and Strategies

• Soil Cleanup
• Either remove it (ex situ bioremediation) or in
  situ (in place)
• In place
• If aerobic may require bioventing
• Most effective in sandy soils
• Removed
• Slurry-phase, solid phase, composting,
  landfarming, biopiles

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Cleanup Sites and Strategies

• Bioremediation of Water
• Wastewater treatment

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Cleanup Sites and Strategies

• Bioremediation of Water
• Groundwater Cleanup

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Environmental Diagnostics

• A promising new area of research involves using
  living organisms to detect and assess harmful
  levels of toxic chemicals.

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Daphnia magna
Environmental Diagnostics
Transparent Thorax and Abdomen
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When healthy Daphnia are fed a sugar substrate
(?-galactoside attached to a fluorescent marker),
they metabolize the sugar and fluoresce under UV
light.
Environmental Diagnostics
When Daphnia are stressed by toxins, they do not
have the enzymatic ability to digest the sugar
and therefore do not fluoresce under UV light.
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Environmental Diagnostics

• Toxicity reduction involves adding chemicals to
  hazardous waste in order to diminish the
  toxicity.
• For example, if the toxicity results from heavy
  metals, EDTA will be added to the waste and the
  effluent will be tested again to determine if the
  toxicity has been acceptably reduced.
• EDTA chelates (binds to) metals, thereby making
  them unavailable to harm organisms in a
  particular body of water.

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Applying Genetically Engineered Strains to Clean
Up the Enviroment

• Petroleum eating bacteria
• Ananda Chakrabarty at General Electric
• Heavy metals (bioaccumulation)
• Bacteria sequester heavy and radioactive metals
• Biosensors
• lux genes

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Environmental Disasters Case Studies in
Bioremediation

• The Exxon Valdez Oil Spill
• In the end, the indigenous microbes did the best
  job
• Oil Fields of Kuwait
• Poses a problem due to the environmental
  conditions

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Future Strategies and Challenges for
Bioremediation

• Microbial genetics
• New types of microbes (from the ocean etc)
• Radioactive materials
• DO A BETTER JOB OF DETERMINING RISK and
  ASSESSMENT OF EXISTING SITES

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Careers in Environmental Biotech

• Biodegradation
• Wastewater treatment plants, organic farming
• Bioremediation
• Environmental clean-up companies, labs developing
  super bugs
• Biocatalysis
• Plastics, degradable and recyclable products
• Other
• Mining companies, oil companies