_Lisa_
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Postby _Lisa_ » Mon Oct 08, 2007 7:14 pm

Perhaps, instead of doing that project, and you are interested in using saliva, you could test if saliva does have disinfectant qualities. This type of project has been done before, a quick search on google should help you to find it. You could also incorporate this into the project you are looking at now. Testing saliva side by side with another disinfectant could yield some interesting results. It would be a unique twist to this project, and it seems to interest you.
-Lisa

binsuabraham
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Postby binsuabraham » Mon Oct 08, 2007 7:31 pm

would it be very different if i use fungi..like yeast?? instead of bacteria??

_Lisa_
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Postby _Lisa_ » Mon Oct 08, 2007 7:45 pm

The biggest difference between using fungi and bacteria is that the fungi might be more resistant to your disinfectant, but it all depends on what you plan to use.
-Lisa

binsuabraham
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Postby binsuabraham » Mon Oct 08, 2007 7:47 pm

wat if i cud use fungi and increase the amount of disinfectant and time??

will normal yeast be enough?? wud it be really hard rite??

_Lisa_
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Postby _Lisa_ » Mon Oct 08, 2007 9:17 pm

You could just reword the project and test the effects of disinfectant on fungi, such as yeast. It wouldn't be hard, it would just be testing different variables.
-Lisa

binsuabraham
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Postby binsuabraham » Tue Oct 09, 2007 8:55 am

how would i know when the bateria is resisting the disinfectant?

wildfirefox
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Postby wildfirefox » Tue Oct 09, 2007 10:39 am

You'll know the bacteria is resisting the disinfectant when the bacteria colonies continue to grow even when you add the disinfectant to the colonies. If you don't see anything growing at all in the spot where the bacteria colonies used to be, well, the disinfectant probably killed a large percentage of the bacteria, or all of them :wink:
Those who can see that do not exist are geniuses. Those who can see what exists are brilliant. Those cannot see what exists are ignorant.
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binsuabraham
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Postby binsuabraham » Tue Oct 09, 2007 11:01 am

nd how do i get the bacteria??? should i order them???

binsuabraham
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Postby binsuabraham » Tue Oct 09, 2007 11:18 am

or would it be enough to use fungi (which is more accessible- yeast) instead of bacteria??

would it make sense to use disinfectants against fungi...bcuz its usually used for bacteria rite?? (im using saliva, Eucalyptus oil and dettol as disinfectants)

will water be enough for my control??? i really dont know anythin else to use...

wildfirefox
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Postby wildfirefox » Tue Oct 09, 2007 11:42 am

If you compare regular bacteria vs yeast vs fungi, fungi has the highest tolerance among the three. Why? Because fungi is a decomposer, which can survive in a very harsh environment in order to breakdown dead matters into usable bio-matters. Between the three, bacteria is perfect for the experiment since they are much more sensitive to the changing environment, and quicker in adapting to the changes around them over a short period of time.

Bacteria can be found pretty much everywhere. Why not try the agar incubation approach, in harvesting bacterial on the kitchen area, around the bathroom sink area, or best yet, on your hands/skin. Just make sure you can find a person/lab that can help you with this.
Those who can see that do not exist are geniuses. Those who can see what exists are brilliant. Those cannot see what exists are ignorant.
- Lao Tsu

_Lisa_
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Postby _Lisa_ » Tue Oct 09, 2007 6:01 pm

Another twist on the project could be using a slice of bread to grow mold, and testing disinfectants straight on the bread slice soaked in water to induce molding. If you do plan to do this project, be sure to get preservative free bread (check out whole foods or another health store) And you must remember to have a control for your project! Hope this helps, let me know if you have any more questions.
-Lisa

adance
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my two cents

Postby adance » Fri Oct 12, 2007 3:34 pm

I judged a science fair last year and there were lots of projects testing different chemicals with bacteria, so once you come up with a hypothesis to test it should be pretty straightforward. Think about how bacteria grow, and what might affect that process.

I like the way you're thinking about saliva as a disinfectant, I've heard that too like when dogs lick a wound it helps it heal better. But, check and see if your fair has rules about culturing bacteria from humans--because I guarantee if you put anything that has been spit on on an agar plate, you will grow whatever's in your mouth. (Maybe your teacher has access to a way to sterlize saliva?)

regarding what to use as a control--consider what your "active ingredients" (the thing you think will actually kill the bacteria) are dissolved in. For example, saliva is mostly water. But other disinfectants might be dissolved in something else like alcohol. As a control, you want to use the closest thing possible to your potential disinfectants.

Since you are using fungi, you might want to test some drugs that are specifically anti-fungi, these are called fungicides and you should find some info if you Google "fungicide."

Good luck!
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binsuabraham
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Postby binsuabraham » Fri Oct 12, 2007 5:57 pm

_Lisa_ wrote:Another twist on the project could be using a slice of bread to grow mold, and testing disinfectants straight on the bread slice soaked in water to induce molding. If you do plan to do this project, be sure to get preservative free bread (check out whole foods or another health store) And you must remember to have a control for your project! Hope this helps, let me know if you have any more questions.
-Lisa


yeah i like this idea...
but, can i still use all the disinfectants...like saliva...???
and i don't understand why the bread with the mold has to be soaked in water? will it make any difference if i don't do it???

nd if i do mold, is it necessary tat i shud have an access to a lab?? can tis be done at home in agar plates??

also, can the control be plain mold soaked in water without the disinfectants?? but tat not have any fungal resistance...

binsuabraham
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Postby binsuabraham » Fri Oct 12, 2007 6:07 pm

since im using two natural disinfectants (saliva nd Eucalyptus oil) vs. two man-made disinfectants (Dettol nd Pears soap), i dont really know wat to support for my hypothesis...like shud i support 'natural disinfectants' in general or specifically 'saliva' ???

my teacher wants me to use "IF.....THEN...." method for my hypothesis...

so all i have is "If there is a decrease in the growth of bacterial colonies while using saliva or Eucalyptus oil (im not sure of wat to support here), then natural disinfectants are more efficient than man-made disinfectants. "

MelissaB
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Postby MelissaB » Sat Oct 13, 2007 8:20 am

"If...then" statements typically refer to something slightly different--you put your prediction after the 'then' statement and your hypothesis before. So it would be more along the lines of 'If natural disinfectants are more anti-bacterial than man-made disinfectants, then we would expect to see fewer colonies on the agar plates using saliva and Eucalyptus oil.'

You can either support 'natural disinfectants' in general or saliva in particular--it's up to you. What has the background research you've done suggested will be most effective? You should base your predictions on that.


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