Science Buddies: "Ask an Expert"

I was wondering if tetrazolium would react if used with oil used from natural oil seeps? I am going to use a tetrazolium indicator with soil that contains oil degrading bacteria and oil and distilled water. Would the tetrazolium turn pink from the bacteria eating the oil? I asked a technician from Caroline Biological Supply and he said it probably wouldn't work? He said it would only work with vegetable oils and not petroleum based oils. But in the lab I am adapting it from, the analysis questions and further study said to try it on petroleum jelly which is a byproduct of petroleum oil. I am confused on why the technician would say that and if it would work or not?

Thanks.

Hi Ama,

The best way to answer your question would be to test it experimentally. I think the assay will work with any bacterium that can metabolize a specific kind of oil because that is what the assay measures, not the oil itself. Are you using Carolina Biological's Slick Oil kit? That uses a different type of bacteria from those that can digest petroleum so I think that is why the technician told you it only works with vegetable oils.

Bacteria are picky eaters. They evolved the digestive enzymes to only break down certain molecules. If you want to do experiments on bacterial remediation of petroleum contamination in soil or water, then you will have to find out which species of bacteria can do this and use them for your tests.

Does this help you? Please let me know more about your project so I can help you better.

Best wishes,

Sybee

Thank you for your reply. I am still researching what bacteria to use but will begin the tetrazolium test soon. I needed reassurance that the tetrazolium would work. I think I will test the tetrazolium anyways even if it doesn't work.

Thanks,
Ama

You're welcome, Ama. I am glad you are sticking with this project. If you need help getting reference articles, let me know.

The tetrazolium assay measures the metabolic activity of cells so would work with any bacteria that are alive and growing. To test how well bacteria can break down oil in soil, you would need to measure some chemical product that is made by the bacteria when they digest the oil. How you do this will depend on which bacteria you use.

Let me know how you make out with the tetrazolium assay and keep posting so we can continue to help you with the project.

Best wishes,

Scibee