Can Aspargaus inhibit
population growth of
yeast cells?
Tiffany Sato
Experium Science Academy
Marlborough School, Ninth Grade
Hypothesis and Goals During digestion, asparagus produces sulfur
compounds, which is beneficial in the reduction of
the growth of cancer cells (Mitchell, 2001).
Therefore, I decided to investigate this further which
led me to the information that asparagus produced
high levels of sulfur. From this, I decided to start
studying the effect of asparagus on yeast activity.
I wanted to see a decrease in yeast activity
compared to a negative and positive control. A
decrease in growth meant that the asparagus, the
high amounts of sulfur, was inhibiting the growth of
the yeast cells.
Yeast Cells
(Saccharomyces
cerevisiae)
Typical eukaryotic
structure
Fast and
incontrollable cell
division
Economically
accessible
Genetic material is
known
Cancer Cells
Typical eukaryotic
structure
Fast and
incontrollable cell
division
Why I used Yeast Cells
and the Similarities
Yeast Cells as a Model
Organism
I realized that scientific studies have shown
thatSaccharomyces cerevisiae could be used as an
alternative to cancer cells when doing research.
(Hartwell, 2001) (Mortimer, 1973)
Research Methods
Can Asparagus inhibit population
growth in yeast cells?
Yeast Activity Growth with
Spectrophotometer
Viable Colony Counts with Agar
Plates
Recipes
• 1% Yeast Extract
• 2% Peptone
• 1% Dextrose
Positive (YPD+)
• Water
Negative (YPD-)
• 1% Yeast Extract
• 2% Peptone
• 1% Dextrose
• 50mL of Filtered Asparagus
Experimental (YPDAsp)
Yeast Activity Growth
with Spectrophotometer
Grow S. cerevisiae in YPD+, YPD-
, YPDAsp Broths
Incubated all cultures for 24 hours
Centrifuge all the different
mediums
Measured the absorbance of each
using a spectrophotometer at
600nm
Compared the Yeast Activity Growth Results
Viable Colony Counts
using Agar PlatesFor my agar
plates, I inoculated a
colony from a colony off a
positive plate.
Incubate for 48 hours at 30oC
Streak onto my three different
plates: positive, negative and experimental
Incubate for 24 hours at 30o C
Record Viable Colony Count Results
Results for Yeast Growth
Activity
Absorbance of Yeast
Activity Sample
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 5 10 15
Ab
so
rba
nc
e (
600n
m)
Sample Numbers
POSITIVE
NEGATIVE
EXPL
Data Table
Data
Average for Negative (without any nutrients) :
0.189 abs
Average for Experimental (with asparagus):
0.488 abs
Average for Positive (with nutrients, without
asparagus):0.633 abs
Conclusions for Yeast
Growth Activity My results from my experiment with the liquid
medium with asparagus had the lowest absorbance
(0.488 abs) compared to my positive control
(0.633 abs ) and higher absorbance compared to
my negative control (0.189 abs). This indicates a
decrease in yeast activity upon addition of
asparagus indicating minimal cell growth.
Results for Viable
Colonies
Experimental
Results
Comparison of the
ControlsNegative Experiment Positive Experiment
Conclusions from Viable
Colonies Although viable colonies have limited
quantification, the pictures show the apparent
difference of structural colonies between the
Positive, Experimental, and Negative.
Positive
• Raised, Corvex Surface
Experimental
• Flat Surface
Negative
• Produced no colonies
Acknowledgements
Thank you to Sigma Xi for this opportunity.
Thank you to RaudhahRahman, Experium
Science Academy, my parents, and those who
have supported me throughout.