Success tastes good. Very good.
I completed another biofilm test on e.coli this week, and this time, the bacteria didn’t get totally wiped
out by test tube bleach. Instead, basically what we found out was that in
extremely low concentrations, neither dish detergent had too huge of an impact
on the biofilms. We noted a 0.5 reduction of bacteria (about 50% of the
bacteria were gone) in the presence of Dawn and a very small reduction with
Cascade. This means that the two dish detergents did not really kill any of the
biofilms of e.coli that you would
potentially find in your gut.
 |
| e.coli plates |
 |
| Detergent plates: Left-Dawn, Right-Cascade |
When I diluted and plated the detergents, I found that there
was significant bacterial growth, which means that both detergents swept away
biofilms that were still able to grow. Most dishwashing detergents can be
classified as surfactants, meaning that they lower the surface tension between
two liquids or a liquid and a solid. Surfactants are part of the reason why it
is easier to scrub away food residue from plates when using dish detergent as
opposed to just water. So in this case, the dishwashing detergents acted as
surfactants for the e.coli biofilms,
sweeping them away from the colonies left on the well plate.
So what does this mean for you?
Well, basically, at least in terms of e.coli, this means that small concentrations of dishwashing liquid
are not harmful to the bacteria. So if you’re in love with using that bottle of
Dawn with the adorable little duckling on it to wash your dishes, you’re
probably ok, because it’s not going to screw up your intestinal e.coli super badly. However, since both
detergents seemed to sweep away bacterial biofilms, accidentally consuming
small quantities of dish soap could move bacterial colonies from one part of
your intestine to another. And since science hasn’t discovered enough about gut
flora yet, we are unsure of whether this movement would be harmful. Just don’t
chug a bottle of Dawn, please. That’s a really bad idea.
За здоровье! To
your health!
Mackenzie
Mackenzie
Woohoo! Results! And фантастика ones too! So what's next for your project?
ReplyDeleteYasss! Спасибо(thank you!) For the remainder of my project, i'll just be doing a crap ton more biofilm tests, but with my other two kinds of bacteria (epidermidis and lactobacillus).
ReplyDeleteHow much of a difference do the different detergents make on your tests? Like why are Dawn and Cascade different? Is it their active ingredients?
ReplyDeleteAlso on the Cascade colony you just said a small reduction of bacteria... Is that less that .01? Because you were pretty specific about Dawn....
How much of a difference do the different detergents make on your tests? Like why are Dawn and Cascade different? Is it their active ingredients?
ReplyDeleteAlso on the Cascade colony you just said a small reduction of bacteria... Is that less that .01? Because you were pretty specific about Dawn....
Well, Dawn is a liquid detergent with an active ingredient of SDS( sodium lauryl sulfate) and Cascade is a powder detergent with an active ingredient of sodium carbonate. They represent two types of detergents that would be commonly seen/used in households. In terms of the effect of Cascade, estimating from the graph there was probably only like a 5% reduction of bacteria.
ReplyDeleteIf you find that the dish detergents aren't harmful to the human gut, what's the next step in the research related to this topic?
ReplyDeleteWe might look into the effects of other products with similar active ingredients, such as toothpaste, or grow bacyeria on different plates to replicate different growth environments.
ReplyDelete