Oil Eaters:
Microbial Bioremediation
Student Guide

Background:
 Biodegradation is a natural process by which microorganisms such as bacteria, fungi, and yeast break down complex compounds into simpler products to obtain energy and nutrients. Due to the biodiversity of the microorganisms that exist in soil and in water, this process may occur anywhere. Many types of toxic soil or water contamination exist. The diversity of microbes allows for specific responses to these contaminants. Common types of microbial "cleanups" are old oil dumps, oil-contaminated land, old landfills, diesel and jet fuels from estuaries, and shoreline contaminations.
    In an aquatic environment, biodegradation of oil is a painstakingly slow process, sometimes lasting years. However, rapid removal of spilled oil from shorelines and wetlands is necessary in order to minimize potential environmental damage to the sensitive marine habitats. Bioremediation is the use of microorganisms to help the biodegradation processes occur faster.
    In bioremediation, scientists add materials to the environment, such as nitrogen and phosphates to stimulate growth and increase the population size of the microorganisms. This is called nutrient enrichment. Seeding is another method of bioremediation. This is the addition of more of the microorganisms also increasing the population size, thus increasing the rate of natural biodegradation.

Optional Materials:
Step 1(For agar experiment model)

  1. Five covered deep tubes of sterile prepared nutrient agar.
  2. One-600 ml beaker.
  3. Hot plate.
  4. Five sterile Petri dishes.


(For nutrient broth experiment model)

  1. Five 125 ml Erlenmeyer flasks and stoppers.
  2. 10 ml of dilute nutrient solution.
  3. 80 ml of distilled water.


(For either experiment model)

  1. One sterile stirring rod.
  2. Five milliliters of automobile oil.
  3. One gram of the following bacterial sources:
  4. One squeeze bottle of the following:
  5. Pipette
Step 2:
  1. Tap water.
  2. 600 ml beaker.
  3. Hot Plate.
  4. Five deep tubes.
  5. Dilute nutient solution.
  6. Five Petri dishes.
  7. Filter disks.
  8. Five ml motor oil.


Procedure:
Step 1:/Step 2:

  1. Acquaint yourself with the location and procedure for proper bacterial disposal.
  2. Disinfect lab area with lysol.
  3. Formulate a hypothesis to be tested using the background information and materials provided.
  4. Outline an experiment, paying close attention to variable and controls. Include a model for a data table, or other method for recording your results.
  5. Discuss your outline with your instructor.
  6. Obtain the necessary materials for your experiment.
  7. Set up the experiment
  8. Place experiment in the area designated by your instructor.
  9. Clean up the lab materials properly.
  10. Clean up the lab station.


Results/Data:

SAMPLE DATA TABLE


Petri Dish
Data
Soil
  
Benthic Soil
  
Parking lot oil shavings
  
Used automobile oil
  
Optional Source
  
Control
  

Conclusions:

  1. Do your results support your hypothesis?  Support and explain your answer completely.
  2. What worked well in this activity?  Explain.
  3. What difficulties did you encounter in this experiment?
  4. What would you suggest to improve this experiment?
 Back to Microbial Bioremediation Page 

 
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The Woodrow Wilson National Fellowship Foundation 
CN 5281, Princeton NJ 08543-5281 - Tel:(609)452-7007 - Fax:(609)452-0066 
Technical contact: lpt@woodrow.org