Oil Eating Microbes
June Strupp
Horicon High School
July 20, 2007
Activity:
This activity will introduce students to microbes that exist that can biodegrade oil and be useful in environmental clean up after an oil spill. The activity will fit into the water unit in which students have already been introduced to the properties of water and the hydrologic cycle. Contamination of water will be discussed and students will be asked to list ways in which water may become contaminated. I would use the video: “Scientists and the Alaska Oil Spill; The Wildlife, The Clean up, The Outlook”, (the video is available from local libraries) to introduce the concept of oil spills and the impact they have on the environment and then do the Simulated Oil Spill Cleanup activity (oil clean up kits can be ordered from Wards) from our Biotech class.
This activity would be used in a high school Ecology course in the water unit. I would like to incorporate the lab of bacteria that degrade oil into this course. I already cover water in my Ecology class and go over water contamination; I would like to add this component to the class to give students a better understanding of how fragile our freshwater is. I don’t think I would remove any information from the course to fit this in. I already use a video to identify water contamination and its impacts, I think I would just replace it and use this video and include the lab.
Course: Ecology
Grades: 9-12
Unit length: 4-5 days (45 minute class periods) to be incorporated into water unit.
Objectives:
1. Students will be able to describe ways in which our water supply may be come contaminated.
2. Students will be able to describe methods of water management.
3. Students will be able to compare and contrast the physical appearance o foil before and after exposure to oil-degrading microbes.
4. Students will determine what microbes are useful in cleaning up an oil spill.
Outcomes:
1. Students will develop correct lab procedures.
2. Students will use correct culturing techniques needed to obtain accurate data.
3. Students will use observational skills to determine if bacterial degradation of oil is occurring.
4. Students will complete data observations in chart.
5. Students will be able to analyze their data and come to a conclusion as to which microbe does a better job at degrading soil.
Background Information
Our water is one of our most precious resources. Only 3% of the water on the earth is fresh water and of that not all of it is available for our use. I feel it is very important for students to have that information and understand the importance of protecting our freshwater. This information would be covered in the water unit. The hydrologic cycle would be covered and students would need to have an understanding of the processes that occur and the potential for contamination within and as a result of the cycle. Posters, diagrams similar to the one below would be used in class to teach the cycle and the concepts relating to it.
Water cycle picture from: http://ga.water.usgs.gov/edu/watercycle.html
A devastating disaster that could occur to our water supply would be an oil spill. Oil tanker accidents account for 10-15% of the annual input of oil into the world’s oceans. The majority of the rest come form well leaks, seepage and purging of tanks. The type and amount of damage from an oil spill depend on factors such as type of oil, weather conditions, organisms in the area and the season.
In March of 1989, the tanker Exxon Valdez hit a reef and released 11 million gallons of oil into the Prince William Sound of Alaska. More than 33,000 seabirds, nearly 1,000 sea otters and more than 100 bald eagles were killed.
(from “Oil Spills” experiment packet)
http://www.epa.gov/swertio1/download/citizens/bioremediation.pdf EPA pamphlet site on bioremediation. This will be used to explain the concept better to the students.
Bioremediation (the use of a living organism to repair environmental damage.) is a method that has been used for oil clean up. There are microbes that will naturally breakdown the hydrocarbons in an oil spill. The microbes engulf the oil droplets, break it down into water and carbon dioxide gases and release the water and gases into the environment. This may be a more desirable manner of cleanup than mechanical techniques.
Exercises:
Day 1:
I would show the students a glass of dirty water and ask them if they would want to drink it. Most would probably say no. (hopefully) then I would ask why? This should lead into a discussion about the water being dirty and water contamination. From there we can discuss ways in which water can become polluted. Discuss pollutants that can be seen and those that cannot. How did the water in the glass become contaminated and then ask the students what would need to be done to the glass of water in order for them to drink it. This can open up discussion about water quality management.
Then a glass of water with oil on top could be shown to the students and the same questions could be asked as before. Elaborate the discussion and ask what type of problems may result in the environment if an oil spill were to occur. You could place a feather into the water and ask how that would affect birds. Again we could ask the students what would need to be done to the glass containing oil in order for them to drink it. How do we get oil out of water? These activities would introduce the students to the potential dangers to our water and environment if an oil spill occurred. This would prepare them for the video the next day.
Day 2:
Give the students the worksheet for the video: “Scientists and the Alaska Oil Spill; The Wildlife, The Clean up, The Outlook”. They will watch the video, answer the questions and discuss after the video. Give lab material to read over for the next day.
Day 3:
Introduce the lab with the question that we asked the other day. How do we get oil out of water? Hopefully students have read the lab procedure and state that we can use bacteria-eating microbes! Have the students run the lab. Students will fill out the lab question sheet when they are done with the lab and tubes will be examined daily and observations recorded.
Simulated Oil Spill Cleanup Lab
Teacher prep before hand:
Rehydrate growth cultures 4 to 5 days prior to the lab.
Materials:
Test tube with caps and test tube rack
Density indicator strips
Culture of oil degrading Pseudomonas
Refined oil
Distilled water (60 ml)
Culture of oil degrading Penicillium
Safety:
Students should wear gloves and goggles during the lab. The oil-degrading microbes are nonpathogenic, but correct safety precautions should be taken.
Introduction: recap was discussed the day before. Define the term bioremediation: the use of a living organism to repair environmental damage. Ask students what we are going to use for bioremediation for an oil spill?
In this lab you will compare the physical characteristics of oil before and after it has been exposed to oil-degrading microbes. Also, you will compare the growth and oil-degrading ability of a single bacteria strain with that of a single fungal strain.
Procedure:
1. Caution: Wear safety goggles and gloves during lab. Keep your hands away from your face to prevent possible contamination.
2. Get needed supplies from the front desk.
3. Label your test tubes for each species of microorganism and the control.
4. Add 5 ml of distilled water to each test tube.
5. Add 5 drops of refined oil to each of the test tubes so a thin layer forms on top of the water. (the microbes will use the oil as their source of carbon)
6. Inoculate each test tube with 5 ml of its labeled bacterial or fungal strain. The control tube does not receive an inoculation. (Why not?)
7. Cap each tube turn it upside-down several times to mix the contents. This increases the dissolved oxygen in the water. (What does this simulates would in a real oil spill?)
8. Incubate the test tubes with the caps half loosened in racks at 30 degrees Centigrade. (the test tubes can be placed in a warm area of the room if there is on incubator)
9. Look for any signs of oil degradation. (What would these be?)
10. Note the color of the oil and any characteristics you see and record them on your data sheet.
11. Number the bars on the density indicator strip from 1 to 5, with 5 being the darkest.
12. Place the strip lengthwise into the test tube holding the #5 end up. Push the strip into the water and record the number that can no longer be seen clearly. Remove the strip and wash it. Repeat the procedure with the other test tube. Record your results.
13. Turn your test tubes upside-down each day and observe and record any changes that you observe. Work on you Lab worksheet as you do this. Do this for the next 3 days.
14. Clean up your work area and wash your hands before leaving the lab.
Day 4 & 5
Students will observe their oil test tubes, continue to work on the lab worksheet, and record the data in their chart. (Start this activity on a Tuesday or Wednesday and then they can and also observe after the weekend.) The following site can be utilized in class for students to gain a better understanding of what happened with the Exxon Valdez Oil Spill and how it was treated:
http://library.thinkquest.org/10867/home.shtml
Simulated Oil Spill Cleanup
Lab Worksheet Name:
22 points
Directions: Answer the questions in complete sentences based on your lab procedure and observations.
1. What is the focus of this lab? (3 pts)
2. Why is it desirable to increase the concentration of dissolved oxygen in water? (2 pts)
3. Why is it necessary to incubate the test tube? (2 pts)
4. Which microorganism do you think will degrade the most oil? How will you know? (3 pts)
5. Describe the initial physical characteristics and appearance of the oil that was placed in the tube. (2 pts)
6. Describe any changes in the physical characteristics and appear and of the oil on day 1 and beyond. List possible causes for such changes. (5 pts)
7. Is there a difference in the rate of oil degradation between the bacterial and fungal cultures? Describe them. (5 pts) Which is more effective at degrading the oil? (1 pt)
Simulated Oil Spill Cleanup Lab Data Collection
0 / Pseudomonas sp.
Penicilliun sp.
Control
1 / Pseudomonas sp.
Penicilliun sp.
Control
2 / Pseudomonas sp.
Penicilliun sp.
Control
3 / Pseudomonas sp.
Penicilliun sp.
Control
Over
Week-
End / Pseudomonas sp.
Penicilliun sp.
Control
Modifications:
I don’t think there will need to be too many modifications for this project with many students. EEN students may need more time with the video to process the information and respond to questions. They can review it during a free period if needed.
Evaluation/ Assessment:
Students will be assessed based on their lab technique and data collection.
There will be a worksheet for the video. (attached)
Participation in discussion.
“Scientists and the Alaska Oil Spill;
The Wildlife, The Clean up, The Outlook”
Ecology Name:
31 points
Directions: While watching the video, formulate answers to the following questions. Use complete sentences in you responses. You may also use the following site to find additional information: http://library.thinkquest.org/10867/home.shtml
1. When and where did the Exxon Valdez oil spill occur? (2 pts)
2. How did the spill occur?(2 pts)
3. What are dispersants and what do they do?(3 pts)
4. Why weren’t chemical dispersants used in the Exxon oil spill?(2 pts)
5. How many gallons of oil were spilled?(1 pt)
6. How many miles of coastline were soiled?(1 pt)
7. The oil spill was first attacked by containment, how did they try to contain the oil?(3 pts)
8. Where does most of the oil go in a spill?(2 pts)
9. Was Exxon prepared for the spill? Why or why not?(3 pts)
10. What was the effect of using hot water to help clean up the oil?(2 pts)
11. How does nature clean up an oil spill?(2 pts)
12. Why were fertilizers dispersed?(1 pt)
13. Why did Exxon leave before they were done treating the shoreline?(2 pts)
14. How were animals affected by the spill?(give three examples) (3pts)
15. What happens when toxins get into the food chains?(2 pts)
Alignment with Standards:
Wisconsin Standards:
C.12.3 Evaluate* the data collected during an investigation*, critique the data-collection procedures and results, and suggest ways to make any needed improvements
C.8.3 Design and safely conduct investigations* that provide reliable quantitative or qualitative data, as appropriate, to answer their questions
F.12.8 Using the science themes, infer changes in ecosystems prompted by the introduction of new species, environmental conditions, chemicals, and air, water, or earth pollution
H.12.5 Investigate how current plans or proposals concerning resource management, scientific knowledge, or technological development will have an impact on the environment, ecology, and quality of life in a community or region