1. Inquiry Lab- Investigating Cheese “Microbiomes”
Essential Question:
How do biologists study living things?

2. Cheesy History
5000 BC (?) - Pouches made from animal stomachs likely provided the Rennet enzymes separating milk casein into curds and whey
The practice of salting foods for preservation included curdled milk
Late 1890’s - Identifying and culturing bacteria led to standardization of cheese products

3. Cheese Production

4. Ancient Biotechnology
Diversity of microbes in cheese making

5. Cheese as a model system
Culturing cheese microbes is helping scientists learn about interactions within microbial communities
Blue Cheese microbes on a Petri dish

6. Different cheeses have different microbial communities

7. Resources (listed from popular to technical sources)
Bacteria in Cheese
The Most Delicious Lab
Microbe Managing - The Life Saving Potential of Cheese
Abstract: Diversity of Bacteria… in Cheese Production
DNA technology reveals microbes in cheese

8. Experimental Design Doing things in a scientific way…. Observe Wonder
Question
PLAY (build a model, perform an experiment)

9. Observe Culture a cheese microbiome
Prepare nutrient agar in Petri dishes
Determine number of dishes you will need
Weigh,measure, and mix powder in a flask
Stir and boil until solution turns translucent
Cool, then pour thin layers into plates
Bring in cheese samples (washed rind)
Using sterile swabs innoculate agar from cheese rind samples
After several days, LOOK at growth!

10. Wonder What kind of bacteria are growing?
Is the community stable or dynamic?
How could we change the community?

11. Question
What condition causes a particular bacterial species to increase in number? Decrease in diversity? Die off completely?

12. Experimental Design Guidelines
(IF) Independent Variable: condition or situation you will set up
(THEN) Dependent Variable:
Must be quantitative
the NUMBER that you will record

13. IF/THEN hypothesis should reflect your question
Hypothesis predicts how variables will change
IF the temperature increases, THEN population of Bac A will increase.

14. Data collection should reflect your question
Independent Variable (x-axis) =
Dependent Variable (y-axis) =