Does Yeast Grow Differently in
Aspartame, Splenda, Sugar, and
Saccharine?
Biochemistry – Division II.
George Malatinszky
8th grade
Classen School of Advanced Studies
Oklahoma City, OK
Abstract
Yeast utilizes the glucose in its environment to make energy. (5)
Aspartame, saccharine, and Splenda (Sucralose) are all man made sugar
substitutes. These substances aren’t supposed to have any calorie content so
yeast life shouldn’t be possible. If yeast is grown in aspartame, Splenda,
saccharine, and sugar, then the yeast will grow fastest in sugar, therefore
sugar is the food on which yeast grows the fastest. 6 mL room temperature
water, 0.6mL sugar and 0.6mL yeast were poured into each test tube. The
tube was then shaken gently. The volume (mL) of the mixture was measured
after 30 minutes. 13 trials were done with each substance.
The trials including sugar had an average volume of 7.4 mL. The trials
using Splenda had an average volume of 5.2 mL. The trials with saccharine
had an average volume of 5 mL. The trials with aspartame had an average
volume of 7.9 mL. Aspartame had showed the most growth. Splenda had
some dextrose (sugar) in it, which might have been the reason for any growth
at all. Saccharine didn’t have any sugar and there was no growth.
A possible reason for the trials of aspartame to produce more growth is
that aspartame really could be used by the yeast. Nevertheless this is an
unlikely explanation. Another explanation is that a lower concentration of
sugar is better the yeast than a high concentration. After the main
experimentations were finished, the latter explanation was tested and it
showed that until a certain extent a lower concentration really is better for
yeast. To verify this, tests with pure aspartame remain to be conducted.
If, Then, Therefore
If yeast is grown in aspartame, Splenda, saccharine, and sugar, then
the yeast will grow fastest in sugar, therefore yeast can use sugar better
than sugar substitutes for energy.
Literature Review
Yeast are unicellular, aerobic or anaerobic organisms. (3) Yeast, like
animals, give off CO2 as a byproduct of respiration. (1)
Yeast reproduce
through budding in which an adult yeast cell grows an offspring from its
body. (2) For reproducing yeast cells need energy. Yeast utilizes the glucose
in its environment to make energy. (4) Sugars are made of 5 or 6 carbon
atoms, along with hydrogen and oxygen, and they are called monosaccharide.
They can bond together to form disaccharides. (5) Aspartame, saccharine, and
Splenda (Sucralose) are all man made sugar substitutes. Aspartame is made
of carbon, oxygen, nitrogen, and hydrogen; its structure is not similar to
sugars. Saccharine consists of carbon chains, oxygen, hydrogen, sodium,
sulfur, and nitrogen; there are many elements that aren’t found in sugar.
Splenda (Sucralose) consists of carbon, oxygen, hydrogen, and chlorine;
Sucralose molecules resemble disaccharides in that they are made of two
rings. These substances are believed to have no calories because organisms’
cells aren’t able to break them down.
Procedure
commercially available baker’s yeast
52 10mL testubes
white cane sugar (C&H Cane Sugar™)
Splenda™
commercially available aspartame (NatraTaste™)
commercially available saccharine (Fasweet™)
room temperature tap water
1)
Pour 6 mL of room temperature water into test tube.
2)
Pour 0.6mL of sugar into test tube.
3)
Pour 0.6mL of yeast into the test tube.
4)
Seal the cap of the test tube onto the top and shake gently.
5)
Repeat steps 1-4 thirteen times.
6)
Repeat steps 1-5 substituting sugar with 0.6mL of aspartame.
7)
Repeat steps 1-5 substituting sugar with 0.6mL of Splenda.
8)
Repeat steps 1-5 substituting sugar with 0.6mL of saccharine.
9)
Place the test tubes on their holder and wait half an hour.
10)
On a spreadsheet record the difference of the current height of the
mixture and 6mL.
Data Collection Tables
(Volume in mL)
Trials
Aspartame
Saccharine
Splenda
Sugar
1
7.5
5
6
7
2
8
5
5
6.5
3
8.5
5
5
6
4
8
5
5.5
9
5
8.5
5
5
8
6
8
5
6.5
7
7
7
5
4
7.5
8
8.5
5
5.5
5.5
9
7.5
5
4
4
10
8
5
4.5
4.5
11
7.5
5
5
5
12
8
5
5.5
5.5
13
8.5
5
6
6
Data analysis

The trials including sugar had an average volume of 7.4 mL, a
difference of 2.4 mL from the starting volume.

The trials using Splenda had an average volume of 5.2 mL, a
difference of 0.2 mL from the starting volume.

The trials with saccharine had an average volume of 5 mL, a
difference of 0 mL from the starting volume.

The trials with aspartame had an average volume of 7.9 mL, a
difference of 2.9 mL.

When trials with different amounts of sugar were done, trials that
had the most sugar did not yield the highest yeast growth, instead
the trials with slightly less sugar had the most growth.
Conclusion
Aspartame was the substance that yeast grows fastest in. The only
aspartame that was commercially available was contaminated with dextrose.
A possible reason for the trials of aspartame to produce the most growth is
that aspartame really could be used by the yeast, although this is an unlikely
explanation. To test this explanation yeast would be grown in pure
aspartame. Another explanation is that a lower concentration of sugar is
better the yeast than a high concentration. After the main experimentations
were finished, this explanation was tested and it showed that until a certain
extent a lower concentration really is better for yeast. To verify this, tests
with pure aspartame remain to be conducted.
Bibliography
1)
Life Science. (n.d.). Holt.
Yeast Produces CO2.
2)
Miller, K. R., & Levine, J. (1989). Biology. Englewood Cliffs, NJ:
Prentice Hall.
From this book I learned how yeast reproduces through budding.
3)
The
Wikimedia
Project.
(n.d.).
Yeast.
In
www.Wikipedia.org.
Retrieved October 5, 2005, from http://www.wikipedia.org/
From this website I learned that yeast cells can be aerobic or
anaerobic.
4)
The
Usborne
Science
Encyclopedia.
(2001).
London:
Usborne
Publishing Ltd.
From this book I learned about the uses for yeast. I also learned that
yeast uses sugar for energy.
5)
Yeast. (1978). In The New College Encyclopedia (p.45,743,767). New
York, NY: Galahad Books.
Aspartame, Saccharine, and Splenda (Sucralose) are man made sugar
substitutes.