Science Project Details:

Examining the effect of temperature on bacteria

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Difficulty: Advanced 7
Cost ($): 50
Time required: < 1 week
Preparation will take approximately one day, while observation and recording of data will be completed over a period of five days
Availability of materials:
Access to laboratory equipment (eg. petri dishes)
Required Skills:
Familiarity with handling of bacteria cultures and access to a laboratory
Safety concerns:

Always follow laboratory safety guidelines and always practice sterile technique when handling microbes. Never have any food or drink at your workstation and always thoroughly wash your hands with disinfectant soap or alcohol before leaving your workstation. Always dispose of used material in a biohazard bag. If none are available, the bacteria should be destroyed with bleach before being disposed of

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Abstract

The objective of this science fair project is to investigate the effect of hot and freezing conditions on the survival of bacteria. The experiment will be carried out by placing E Coli, Streptococcus and Bacillus bacteria at -78 degrees Celsius, 0 degrees Celsius, 25 degrees Celsius, 60 degrees Celsius and 100 degrees Celsius

Hypothesis

Bacteria will be deactivated and destroyed at temperatures above 60 degrees Celsius.

Scientific Terms

Bacteria, microorganism, radioactive waste, acidic, pathogen

Background

Bacteria

Bacteria are small single-celled microorganisms that measure only a few micrometers in size and exist in various shapes such as spheres, rods and spiral. They can be found almost everywhere around us, even inside our body. . Some bacteria have also adapted, through mutation and evolution, to environments that are considered inhospitable for most living organisms, such as the earth’s crust, acidic water from hot springs and even radioactive waste.

Although most bacteria around us are harmless, some bacteria, which are known as pathogens, can spread diseases and cause people to become ill. It is therefore important to maintain our personal hygiene and to maintain a safe environment by cleaning our homes with disinfectants. However, there are also friendly bacteria which are essential for our survival, such as those that live in our stomach and intestines. These bacteria are useful in helping us digest our food.

Bacterial growth is governed by factors such as temperature, pH, salt concentration, nutrient and oxygen. The optimum temperature for most bacteria to survive and grow ranges from 25 degrees Celsius to 40 degrees Celsius, and the optimum pH ranges from 6 to 8. However, some bacteria, such as psychrophiles and thermophiles, are able to survive and reproduce under more extreme temperatures, at 0 degrees Celsius and 91 degrees Celsius respectively.