Transcript Bacteria - MeyerMathScience2016

Bacteria
The Haunts and Horrors
Experimental question
What is the effect of different
solutions of water and other
ingredients, on the growth of
bacteria from the boys bathroom
sink?
Procedure
1: fill 3 vials half full of water.
2: Fill 1 vile with ¼ teaspoon of sugar, and a second vial with ¼ teaspoon of
salt. Keep one vial with only water. This will be the control. Make sure the
salt and sugar dissolve.
3:Take a swab of bacteria (it doesn’t matter where it’s from, as long as it’s all
the same place with all 3 swabs. We used the handle of a boys bathroom
sink) with 3 Q-tips.
4: Swirl one of the Q-tips in each vial thoroughly.
5: Spread agar on the bottom of 3 petri dishes.
6: pour half of the salt water solution in one petri dish, half of the sugar
solution in another petri dish, and half of the control (water) in the last petri
dish.
7: label the petri dishes with whichever solution you used in it. Take
observations regularly.
Hypothesis
We predicted that out of the three
solutions we created, salt would be
most resistant to the bacteria
because it is used to cure meat, while
sugar would grow the most bacteria
because sugar rots your teeth, but
the control we weren’t sure about.
Data table
Day 2
(4-28-16)
Day 6
(5-2-16)
Final day
Day 10
(5-6-16)
Salt water
No bacteria has
grown. Only the
agar is seen.
Still no bacteria.
Little white
grainy looking
dots have formed
Sugar water
There is a strange It looks the same
yellow growth. It
as 4 days ago,
is a bit watery,
but less watery
and looks like it
and the yellow
may be forming
growth is
colonies.
clumping in some
spots and
thinning in other
parts.
It looks the same
as day 6. A yellow
sheen spread
across the agar.
It is thicker in
some parts and
thinner in others.
Control
(just water)
PU! It stinks! It
looks similar to
the sugar water,
but it has lighter
yellow stringy
things.
The control looks
just like the
sugar, but slightly
less yellow
growth.
Control looks the
same as the
sugar, and the
stringy things
have
disappeared.
Day 4
Salt water
Control
Sugar water
FINAL DAY – Day 10
It is hard to see, but
little white specks have
grown on the salt dish.
Conclusion
We were correct in our hypothesis! The salt solution
didn’t grow any bacteria until the final day, while the
sugar solution grew the most. However, the sugar
grew only a little more than the control, which
suggests that sugar only enhanced the growth of
bacteria slightly. However, we were unable to a
identify the growth. So, in conclusion, salt is a good
cleaner, or at least to most of the bacteria that grow
in a boys bathroom sink. But don’t use sugar,
because it helps the bacteria grow! And don’t leave it
just to water, either. I hope this encourages you to
use good cleaning products on your sink!