Topic- Oil- Degrading Bacteria
Title- Oil Be Seeing You

Developed at Woodrow Wilson Fellowship Foundation Biology Institute, by Elizabeth Burck, Peggy Deichstetter, Sue Draper and Su Ellen Silverman – July 1999

Recommended grade level: 10-12
Courses- Biology, Microbiology, Environmental Science

Purpose- To determine the relationship between soil environments and the activity of petroleum-degrading bacteria.
 

Skills/Knowledge stuents need prior to lab:

In order to fully participate in this activity, the student should:

• possess a working knowledge of bacteria ( know that they are microscopic, cause decomposition, and are found everywhere.)
• be able to measure accurately using a graduated cylinder and measuring tape.
• know that bacterial growth can be detected in two ways in this lab:  1) the medium in which it grows can become “cloudy” or turbid as the population of bacteria increases, and 2) the degradation of the mothball indicates that the bacteria are “eating” it as a carbon source.
• have some appreciation of the environmental impact created by to oil spills. This might include a local  scenario or a highly publicized spill such as the Exxon Valdez.  Much information on the latter is available in literature and on the Internet.

Materials
5-clear,covered experimental containers (125ml minimum)
5- volume-measuring containers
4- 10 ml. Pipettes and pipette pumps
4 collection bottles
Clear metric ruler
Distilled water
Moth balls
30 ml. Nutrient broth, Miracle-gro or dissolved chicken bouillon cube
Rubber gloves
Lysol or 10% bleach solution
Paper towels

Troubleshooting:

1. Teachers should carefully read and follow all product warnings on the label of the mothball box.
2. Teachers should obtain and file an MSDS sheet on naphthalene as per OSHA requirements.
3. Data collection must respect the harmful nature of the mothballs (naphthalene).  It is for this reason that the recommended data collection and analysis method is not highly quantitative.  Students should not handle the mothballs.
4. To insure data consistency under these conditions, be sure to use the same measuring device (plastic measuring tape) and, in addition, have the same person do all the measurements.
5. The turbidity of the growth medium can be used for purposes of evaluation of bacterial growth.  Increased turbidity indicates bacterial growth.
6. Oil degraders are aerobic.  Always insure oxygen availability.
7. Due to the inquiry nature of this lab, students will need additional time to formulate methodologies and perform investigations.
8. This activity requires large numbers of containers.  Students can provide containers, provided they are clean and clear plastic or glass.

1. Survey local service stations to determine their methods of oil disposal.
2. Take a field trip to an oil refinery.
3. Do an internet search on applications of bioremediation.
4. Isolate and identify microbes from cultures.  (Advanced)

Bibliography
Atlas/Bartha, Microbial Ecology Fundamentals and Applications.
Benjamin/Cummings Publishing Co. Inc., 1998
http://www.gi.alaska.edu/ScienceForum/ASF12/1276.html
http://www.obio.com
http://www.epa.gov.oilspill
http://chemcourses.uscd.edu/CoursePages/Uglabs/MSDS/naphthalene-baker.html