paigeispretty
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Oil Spills

Postby paigeispretty » Wed Oct 08, 2014 2:01 pm

Hi-

I need help with my science fair experiment. I am now in the research stage. But I am having trouble with a core question. I am thinking about finding a natural substance such as bacteria that could consume the oil. What should I do to advance my project so that I can go to the science competitions?

SciB
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Re: Oil Spills

Postby SciB » Thu Oct 09, 2014 1:09 pm

Hi,

There are several species of bacteria that can digest petroleum and convert it to non-harmful byproducts. Oil spills could occur in fresh water but are more likely in salt water, so your bacteria have to survive in a saline environment. One with the jaw-cracking name of Alcanivorax borkumensis [‘the alkane-eating bacterium of Borkum’] is a naturally occurring marine bacterium and a prime candidate for bioremediation of oil spills. It is able to digest a wider variety of hydrocarbons than other bacteria and usually out-competes them: http://en.wikipedia.org/wiki/Alcanivorax

A. borkumensis also produces a bio-surfactant, a natural detergent that helps to disperse and break up the oil into droplets. This makes it easier for the bacteria to digest it. Some of the research being done now centers on what nutrients such as phosphate or nitrate might be added to promote the growth of A. borkumensis: https://microbewiki.kenyon.edu/index.php/Alcanivorax http://www.ncbi.nlm.nih.gov/pubmed/23645199

Are you planning on testing A. borkumensis as part of your bioremediation project or just mentioning it as a potential addition? You can buy a pure culture of the bacterium from the American Type Culture Collection (ATCC) but it is quite expensive: http://www.atcc.org/products/all/700651.aspx

If you do want to use it, I would call around to some research or testing labs and see if anyone will give you a culture as a gift in support of science education.

Let us know if you have more questions.

Good luck!

Sybee

paigeispretty
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Joined: Wed Oct 08, 2014 10:14 am
Occupation: Student: 11th grade

Re: Oil Spills

Postby paigeispretty » Mon Oct 20, 2014 9:33 am

Hi-

My question is: Is there an optimal environment of water that a bacteria can clean up an oil spill?
Is the bacteria you listed neutral to freshwater, marine water, or estuaries? If so, I need a bacteria that is neutral otherwise my experiment won't work.
Also, what method should I use to check how much oil they cleaned?

Thank-you.

SciB
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Re: Oil Spills

Postby SciB » Mon Oct 20, 2014 6:56 pm

Hi,

The bacterium I was talking about, A. borkumensis, is a marine bacterium used to clean up oil spills in the ocean which are much more likely to occur than oil spills in fresh water. But if you have to do your experiments on fresh water then I would suggest using Bacillus subtilis. This bacterium will grow in water supplemented with a specific mineral salts mixture containing the following amounts per L: K2HPO4, 3 g; KH2PO4, 1 g; NH4Cl, 0.5 g; NH4NO3, 0.1 g; Na2SO4, 0.1 g; MgSO4-7H20, 10 mg; MnSO4*4H20, 1 mg; FeSO4.7H20, 1 mg; CaCl2, 0.5 mg; pH adjusted to 6.8-7.0.

You can buy B. subtilis from Carolina Bio: http://www.carolina.com/catalog/search- ... SearchForm

Normally when B. subtilis is grown in liquid culture glucose is added as the carbon source, but if you add oil instead, such as mineral oil, the bacteria should use that and grow. The better the bacteria use the oil the faster they will grow. You could test the effect of reducing the salts in the medium to one-tenth of their optimal concentration on the degradation of oil. You don’t need to measure the oil itself, just count the bacteria after incubating them for a few hours with the oil. The greater the number of bacteria, the more oil was degraded.

Bacterial counts are usually done by making serial dilutions of a culture, plating them on agar in a Petri dish, incubating them for 24-48 hours at 21-30C and counting the resulting colonies. If you have never done this before here’s a youtube video that shows how it’s done. You can buy the agar plates from Carolina Bio.

Here’s a good website that defines what it means for bacteria to ‘clean up’ oil and explains the various ways that different bacteria digest crude oil: http://www.dfo-mpo.gc.ca/science/public ... x-eng.html

Here’s a paper that lists the various bacteria that can degrade oil:
http://www.hindawi.com/journals/btri/2011/941810/
Nine bacterial strains, namely, Pseudomonas fluorescens, P. aeruginosa, Bacillus subtilis, Bacillus sp., Alcaligenes sp., Acinetobacter lwoffi, Flavobacterium sp., Micrococcus roseus, and Corynebacterium sp. were isolated from the polluted stream which could degrade crude oil.

Here’s a quote from the paper talking about the effects of nutrients on the ability of bacteria to degrade oil:
“Nutrients are very important ingredients for successful biodegradation of hydrocarbon pollutants especially nitrogen, phosphorus, and in some cases iron [34]. Some of these nutrients could become limiting factors thus affecting the biodegradation processes. Atlas [35] reported that when a major oil spill occurred in marine and freshwater environments, the supply of carbon was significantly increased and the availability of nitrogen and phosphorus generally became the limiting factor for oil degradation.”

“The most rapid and complete degradation of the majority of organic pollutants is brought about under aerobic conditions.” In other words, the bacteria need oxygen to digest the oil and grow.

If you need more information for your experiments please let us know. It would be helpful to the experts if you would briefly state your hypothesis and outline the experiments you plan to do to test it.

Good luck!

Sybee

SciB
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Re: Oil Spills

Postby SciB » Mon Oct 20, 2014 8:04 pm

I just realized that I forgot to include the link for the Youtube video on making serial dilutions and plating E coli. Here it is:

http://www.youtube.com/watch?v=pmRUBYlPMBM

Sybee

paigeispretty
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Re: Oil Spills

Postby paigeispretty » Wed Oct 22, 2014 8:01 pm

Thanks! But will I need to change my science fair question if i'm going to test the effect of reducing the salts in the medium to one-tenth of their optimal concentration on the degradation of oil? If so, what would it be? Or is there to still measure that but include my question regarding the optimal environment for bacteria to better clean up an oil spill.

SciB
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Re: Oil Spills

Postby SciB » Wed Oct 22, 2014 8:59 pm

Hi,

The point is that you don't know the optimal environmental conditions for bacteria in the wild. That's why you have to test different conditions. The bacteria won't grow in distilled water. They need nutrients--the question is how much. If an environmental engineer is called in to do bioremediation on an oil spill in a pond, he or she needs to know what to add to the water to make the bacteria grow fast and eat the oil as fast as possible.

So, you really aren't changing your original proposal, are you? Can you please tell us exactly what your hypothesis was and how you planned to do experiments to test it? When we have to guess exactly what your project involves it is hard to answer your questions. Please describe your experiments so we can help you better.

Sybee

paigeispretty
Posts: 15
Joined: Wed Oct 08, 2014 10:14 am
Occupation: Student: 11th grade

Re: Oil Spills

Postby paigeispretty » Fri Oct 24, 2014 9:54 am

my hypothesis was that the bacterium would react better in a freshwater environment opposed to a saltwater environment. I was going to test this by using the bacterium in two different bodies of water (freshwater and saltwater) and measure how much oil it consumed. how can I incorporate how nutrients effect the degradation of oil into my experiment?

SciB
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Joined: Fri Feb 01, 2013 7:00 am
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Re: Oil Spills

Postby SciB » Fri Oct 24, 2014 2:18 pm

Hi,

Most of the bacteria I read about online live in the ocean so they may not survive in freshwater. Which bacteria were you planning to test? If an oil spill company wants to clean up a spill in fresh water they will use a bacteria that is specifically suited to living in fresh water. My idea is to try adding some nutrients to the water like nitrate or phosphate to make the bacteria grow better and eat more oil. There are also chemicals called dispersants that can be added to the water to make the oil easier for the bacteria to digest. They are natural emulsifiers that turn the oil into small droplets.
I
Let us know what bacteria you plan to use and we can try to help you design your experiments for whatever you decide to do.

Good luck!

Sybee

paigeispretty
Posts: 15
Joined: Wed Oct 08, 2014 10:14 am
Occupation: Student: 11th grade

Re: Oil Spills

Postby paigeispretty » Sun Oct 26, 2014 4:48 pm

I plan to use the bacteria that you suggested.


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