Shanisha Gustus & Anell Delgado 710

How will temperature change affect the growth of bacteria? Question:

Variables Constant: Amount of temperature solution in each beaker, amount of salt and vinegar, amount of time in each place IV: Temperature change DV: The growth of bacteria

If we place the solution in a warmer environment, then the bacteria will develop faster than the solution in a cooler place because in order to keep foods fresh, you refrigerate them as they get spoiled, growing bacteria on a room temperature place

Background Info  Lower temperature will inhibit or completely stop bacteria growth, but not kill bacteria. The best temperature for fastest growth of some bacterial strains (such as Ecoli) is the human body temperature at 37c. However most species cannot survive in extreme temperatures. One way to kill common bacterial pathogens using heat is boiling a common sterilization technique.

Material 6 200mL beakers 2 beef bouillon cubes Teaspoons Vinegar water salt

 1: Label six 200-mL beakers 1-6. Dissolve beef bouillon cubes in 600 ml of hot water. Measure then pour 100 ml of this soulution into each beaker.  2. Add a teaspoon of salt to 1 and 2, a teaspoon of vinegar to 3 and 4, and add nothing to 5 and 6.

Continuation  3. Place 1,3, & 5 in a warm place and 2,4 & 6 in a refrigerator  4. Observe the beakers after 48 hours. Materials: 6 200mL beakers, 2 beef bouillon cubes, salt, vinegar, teaspoons & water.

timeCold environmentHot environment Day 1 /24 hrsNo change Day 2/48 hrsNo change Day 3/72hrsNo change Day 4/ 96hrsNo change Day 5/120hrsWater starts to evaporate and color starts to change in the containers Color starts to change in all three containers Day 6/ 144hrsSome water evaporated and the hardness starts color still changes and mold starts to grow Day 7/168hrsMost water evaporated and the remains was hard Some water evaporated and color changes

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C ONCLUSION How will temperature change affect the growth of bacteria? Temperature change will affect the growth of bacteria because the bacteria will grow faster in one climate than the other. In this case the three cups that was left out grew bacteria faster than the one in the refrigerator.

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