1. Chapter 9
Bioremediation

2. Biotechnology and the Environment
Environment – describes everything that surrounds a particular organism
Other organisms
Soil, air, water
Temperature, humidity, radiation

3. 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

4. Biotechnology and the Environment
What are the events that triggered the interest in environmental biotechnology?
Rachel Carlson’s Silent Spring (DDT)
Love Canal
Burning of a River
Exxon Valdez in 1989

5. 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

6. 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

7. 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

8. Biotechnology and the Environment
Garbage Test
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

9. 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

10. 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: Doesn’t cycle between numerous oxidation states only soluble and insoluble form

11. Carbon Cycle
CO2
Organic compounds

12. Nitrogen Cycle N2 cyanobacteria leguminous decomposition Fixation
ammonification
NH3
NO2-
nitrosomas
Nitrification
Pseudomonas
Bacillus
Paracoccus
NO2-
Denitrification
nitrobacter
NO3-

13. Sulfur Cycle
Atmosphere
SO2
H2SO4
Organic sulfur
S SO4
H2S

14. Phosphorus Cycle Sea simple Phosphates Phosphate rocks
Phosphates too complex
for plants to absorb
from the soil
Sea simple
Phosphates
Phosphate
rocks
Microbes Breakdown
complex compounds

15. Biotechnology and the Environment
Scientists learn from nature in the 1980’s
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

16. 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.

17. 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)

18. 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

19. Bioremediation Basics
Some are known to be potential carcinogens and mutagens

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

21. 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

22. Bioremediation Basics
Example:
Na + Cl2  NaCl
reduced +1 -1
oxidized

23. 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!

24. 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)

25. 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

26. 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

27. 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?

28. 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

29. Cleanup Sites and Strategies
Bioremediation of Water
Wastewater treatment

30. Cleanup Sites and Strategies
Bioremediation of Water
Groundwater Cleanup

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

32. Environmental Diagnostics
Daphnia magna
Transparent Thorax and Abdomen

33. Environmental Diagnostics
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.

34. 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.

35. 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

36. 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

37. 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

38. 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