Is there Really Bacteria in My Yogurt?

By: Molly Neu and Nathaniel Beaulieu Is there Really Bacteria in My Yogurt?

Is there really bacteria in my yogurt? Question

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. Background Information

If there is bacteria in my yogurt, then it’s good bacteria and it’s keeping me healthy. Hypothesis (If…then)

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

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 Materials Continued

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

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. Procedure Continued

Analysis

Thanks for watching BY: Molly and Nathaniel

Is there Really Bacteria in My Yogurt?