Transcript Is there Really Bacteria in My Yogurt?

By: Molly Neu and Nathaniel Beaulieu
IS THERE REALLY BACTERIA IN MY
YOGURT?
QUESTION
Is there really bacteria in my yogurt?
BACKGROUND INFORMATION
Dairy products have “live cultures” or bacteria
in them.
 We need certain bacteria to stay alive, so some
food producers add bacteria to dairy products.

HYPOTHESIS (IF…THEN)

If there is bacteria in my yogurt, then it’s good
bacteria and it’s keeping me healthy.
MATERIALS
Large Pyrex bowl
 Stiff plastic cutting board
 Medicine droppers
 Antibacterial dishwashing liquid
 Metal paper clip
 Disposable gloves
 Paper towels
 70% isopropyl rubbing alcohol
 Bottle cap
 Nutrient edger plates
 Permanent marker

MATERIALS CONTINUED
Warm room (72-80 degrees Fahrenheit)
 Adult helper
 Lab notebook
 Unopened bottle of distilled water
 One 6 ounce container of Play - doh
 Tea light
 Matches or lighter
 Unopened container of fresh yogurt

PROCEDURE
1.
2.
3.
4.
Make sure materials are clean
Bend paperclip into triangular shape with a
handle
Suck up rubbing alcohol into one of the
medicine droppers. Sterilize droppers.
Using one of the sterilized droppers, mix the
top of a new yogurt pack onto one of the
plates.
PROCEDURE CONTINUED
5. Use the second sterilized dropper to suck up
distilled water and mix it in with the yogurt.
6. Scrape the yogurt onto an agar plate with the
paperclip.
7. Put the agar plates into an upside down bowl
with a tea light candle and use Play-Doh to seal
the edges of the bowl.
8. When the tea light goes out and check for
cracks in the Play-Doh.
PROCEDURE CONTINUED
9. Leave them under the bowl for six days.
10. Use the graph below to record the results of
the bacteria growing on the plates.
Agar Plates
#1
#2
#3
#4
Are Bacteria
Colonies visible?
Are there different
types of Bacteria
ANALYSIS
Agar Plates
#1
#2
#3
#4
Are Bacteria
Colonies Visible?
Are There Different
Types of Bacteria?
BY: MOLLY AND NATHANIEL
Thanks for
watching