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Science fair topic?- ecoli? - (Oct/09/2006 )

I was wonder if you have any ideas on what i should do for my science fair project. I want to do a project on ecoli. Do you have any ideas which non-pathogenic ecoli i should use. I was planning to study the factors of ecoli but i need to narrow it down. I was planning on which substance eliminates ecoli the best? Do you have any ideas guys?


This project can be done many ways. With ecoli, you would need a supply of a pure culture. You could buy this from a varity of sources. I would suggest DH5 alpha strain as this is a standard laboratory strain. You could also buy LB plates from a company or make them yourselvf depending on your access to matierials. You would treat cultures with various amounts of cleaning products for a certain period of time and test the number of surviving colonies.


if you wanted to do a science fair project on bacteria (maybe not e.coli specific) why not find where the highest concentration of bacteria live in your school (swab around lots). we did that at school, and it was fun (but disgusting).

but if you want to do e.coli specific, umm, you could expose it to UV light, and see if they grow differently...or use different light wavelengths... or how about the effect of normal and antibacterial cleansers (chlorine, soap, bicarb, etc) on e.coli?

we have a ex-microbiologist in our lab for the moment, and she says, use cat poo (seriously, yuck)... and grow it up in milk. not sure how safe that is though....
i'd use a K12 strain. they're the most studied, and probably relatively easy to get.



on a slightly different tack

you could try investigate the properties of these "good" bacteria (lactobacillus, bifidus) in drinks like activia etc....

you could look at whether they can withstand different conditions and count colonies retrieved.

could show which one was best or if it is all nonsense, which i suspect it is

just an idea!!



Have you thought about testing the sensitivity of E. Coli to different types of antibiotics?
It may be a good topic because then its about E. Coli AND antibiotic sensitivity/resistance which is a very important and relevant issue at the moment.

There are a number of techniques available for this kind of testing. The best one and one I have personally used in labs is that of disc diffusion.

Basically....filter paper discs containing standard concentrations of various antibiotics are placed on a freshly innoculated lawn of bacteria (in your case, E. Coli) The antibiotic diffuses radially outwards from these discs and the zone of inhibition of growth (if any) around the disc can be measured and used as an indication of susceptibility of resistance.
if that sounds a bit weird here is my little diagram i made..apologies for dodginess.

To make it more interesting. You could use a few bacterial a couple of strains of Staph Aureus, E.Coli, Kleb. Pheumoniae etc. And test them against a few different antibiotics....So you would have 4 discs (one e. coli, one staph. a pennicilin resistance strain, one staph a pennicilin sensitive strain, one kleb pneumoniae) each with 5-10 discs of antibiotics.

this way you would be showing the way the same antibiotics affect different bacteria different...and thus you are showing how important it is to use appropriate antibiotics to counter different types of bacteria.

-Anna Karenina-

apologies for double post
if you are interested in doing something like this project but are not sure how to go about it..message me and i will send you a procedure

-Anna Karenina-