Science Buddies: "Ask an Expert"

I was wondering which type of bacteria I should use for my experiment.I am testing the efficiency of different nutrient concentrations on the biodegradation of seep oil. Which bacteria would be the best for that?

Hi Ama,

Bioremediation is a great topic for science projects now after the oil spill in the Gulf of Mexico and the recent oil pipeline break in Arkansas, which is still being cleaned up. Bacteria are great little chemical factories, easy to grow and able to digest a wide range of substances including hydrocarbons.

But some bacteria are better at it than others and I will try to help you in selecting a likely subject for your study. I assume you have done some googling about which bacteria are good at cleaning up oil. I searched and found a really intriguing article about a group of Chinese scientists who used chicken manure to successfully degrade oil in contaminated soil:

http://www.newsobserver.com/2010/06/03/ ... icken.html

http://www.sciencedaily.com/releases/20 ... 102729.htm

It turns out that the manure contains a mixture of several types of bacteria including Pseudomonas and Bacillus species. I did a further search on these and found a scientific paper in which these two types of bacteria were tested for bioremediation of oil-polluted soil. I have attached the article for you to take a look at. It is scientifically technical, so i don't expect you to understand all the details, but the take-home message is that Bacillus can eat soil oil under appropriate conditions.

From your posting I see you are proposing to test the effect of various nutrients on how well the bacteria can break down oil. In order to test this, you need bacteria that normally grow in dirt and there are two common ones that also eat oil, Pseudomonas aeruginosa and Bacillus subtilis. These are both available from Carolina Biological Supply as living cultures that you can grow:

http://www.carolina.com/bacteria/bacill ... s+subtilis

P. aeruginosa is a good digester of oil, but it is also a human pathogen and i would not recommend using that as your test organism unless you have access to a university microbiology lab with biosafety level 2 containment and someone to supervise your work. The other bacterium, B. subtilis, is harmless to humans and cultures can be purchased for home use from Carolina Bio.

Please repost to Scibuddies with more information about your project. I like your idea and want to see it come out successfully, but like all science projects the planning stage is most important. I can help you more when I know what it is you have in mind to do and how you plan to do the experiments.

Best wishes,

SciB

Thank you so much for your response. It really helped along with what my mentor said.
I am working with a mentor at the Madrona Marsh in Torrance. We already decided to use marsh water with the seep oil. We are going to use a warm water bath to keep the temperature constant. The oil will be with water and nutrients. We are thinking about using different concentrations of phosphates. We are still in the planning stages and won't start for a couple of weeks of so. My mentor is talking with the Carolina Biological Supply to find out which type is best.

Thanks for your help. I really appreciate it.