Measuring How Oil Breaks Down

[deleted-517332]

For my science fair, I'm trying to find out what mushrooms other than the oyster mushroom can break down oil (I'm planning on using motor oil and contaminating soil with it to mimic oil spills). I just don't know how to measure my science fair and the amounts of oil the mushrooms have broken up.

[SciB]

Wow! That's a great idea to use fungi. From what I have read these amazing organisms can do just about anything if you can find the right one.

Bioremediation--getting rid of spilled oil by having an organism like fungi or bacteria break it down is probably the best way to handle it for the environment: no chemical residues in the soil or having to remove tons of contaminated dirt to a long-term landfill.

I found a good reference for biormediation by fungi that you should read if you haven't already seen it: https://hilo.hawaii.edu/campuscenter/ho ... utants.pdf

The scientific article mentions the oyster mushroom but also other kinds that are classified as 'white-rot' fungi: http://www.davidmoore.org.uk/Assets/Mos ... tfungi.htm

"White rot fungi are robust organisms that have a high tolerance to toxic environments, making them ideal to use for bioremedial purposes." This is a quote from the paper. Apparently the enzymes that the white-rot fungi use to break down the wood polymer lignin can also work on hydrocarbons in oil. But where will you get white-rot fungi? You can buy a species of white-rot fungus from Carolina Biologicals (https://www.carolina.com/catalog/detail ... HfEALw_wcB) but I am one who likes to do things myself so I would try to find a white rot fungus in the woods and use it for the experiment.

The type of fungus you want is the one that can break down lignin and these are called 'white-rot' fungi because the wood that they feed on turns whitish or yellowish when the colored lignins are degraded. One type that I am familiar with and which is quite common is called honey mushroom and the genus name is Armillaria: https://en.wikipedia.org/wiki/Armillaria

Remember that the actual body of the fungus, the part that contains the enzymes that decompose hydrocarbons, is NOT the common mushroom cap that you see while walking in the woods. These mushrooms indicate that the fungus is there in the ground or inside wood in the case of honey mushroom. The mushroom body is called the mycelium and consists of a long, branching network of whitish 'threads' that infiltrate and feed on the wood. This is the fungus part that you want to test as an oil eater.

The problem is how to do the experiment. You probably don't have 6 months to do this project and, depending on what part of the country you live in, it may be too cold for a fungus to be active outside. If you could use wild honey mushrooms to degrade motor oil that would be great but that may not be possible under your conditions.

The Plan B for this project would be to use the fungal culture available from Carolina Biologicals and do the oil degradation test on an agar plate: https://www.carolina.com/prepared-biolo ... +malt+agar

Here's an interesting TED talk about mycoremediation, the use of fungi to clean up pollution, but not especially helpful for your specific project: http://saphiet.wixsite.com/bioremediati ... emediation

I have been trying to come up with a way for you to measure the amount of oil decomposed by the Schiz white-rot fungus that doesn't require a lab and expensive equipment--and I have not found anything on the net that shows this. I would get the fungal culture from Carolina and try growing up some of the Schiz fungus on an agar plate on which you have spread a small amount of the oil.

What is a 'small' amount? I don't know. Maybe one drop from a dropper would be enough. What you should see, comparing the oil-treated plate to one that has no oil, is that the fungus is able to grow in the presence of the oil and break it down. If the oil kills the fungus then the experiment is all over. No, then you try it again with LESS oil.

You could call Carolina Biologicals and talk to someone there who knows about the Schiz fungus. Tell them you are student doing a science project and they will be very happy to try and help you. Often they have just the practical information you need because they are working directly with the organisms and may have talked to someone else who did a project like yours.

Maybe some of the other experts can help with this question. There have been several projects proposed to degrade oil in water or soil and I just don't know how to measure the amount of oil degraded without using chemical and instrumental analysis. Any ideas?

Good luck,

Sybee

[deleted-517332]

Hi Sybee!

Thank you so much for the help, it really guided me with my research and immensely helped me with developing a procedure. I emailed Carolina Biologicals like you suggested, but unfortunately, they couldn't offer any advice on the matter. I recently decided to measure my science fair using oil viscosity and API degree. I don't have a lot of insight onto the those parameters of classification yet, but my science teacher thought it sounded plausible.

I was wondering if it was possible to test more than the Schiz fungus using the agar plates. Is it possible for me to make a fungal culture myself and test the wild honey mushroom?

[SciB]

Hi!

Glad you were helped by my last post.

Yes, you can grow your own honey mushroom mycelium. You'll have to do some research online to find out the best way but I know fungi grow well on certain kinds of agar such as potato dextrose agar (PDA). Here's a recipe for how to make it: https://microbiologyinfo.com/potato-dex ... teristics/

Try to get a relatively pure culture of the honey mushroom mycelium growing on the agar before you add the oil so that there are not other fungal or bacterial colonies present that might alter the results. Also, be careful with the cultures because there are fungi that are human pathogens. Read more about that when you do your online search. Always wear gloves, protective eye shields and a particle mask.

Good luck!

Sybee

[deleted-517332]

I've run into a problem with measurements again. I had chosen to use oil viscosity to measure how the oil degraded, but most viscometers/the ones that I need are way out of my price range. Do you know of a site that sells lab materials for a price that isn't so exorbitant? Thank you!

[SciB]

You can make a simple viscosity tester for very little cost. Take a look at this video: https://www.youtube.com/watch?v=qIYnBC1cV20

Since you will only be putting a couple of milliliters of oil on the agar plate you may need to scale down the size of the cup you use for the oil to run out of. Also, you will have to measure the oil very carefully so that you put exactly the same amount in the cup each time. The hole in the cup has to be a size that allows the oil to run out in a stream. If it just drips it won't work.

I don't know if the fungus will change the viscosity of the oil. It might degrade it completely, meaning that you will just have less oil on the plate. You will know exactly how much oil you put on the plate so if you can remove all of it then you can measure the volume after the oil has remained on the agar for some time and see whether the volume has decreased. The big problem here will be pipetting off ALL the oil but do your best.

Good luck!

Sybee