Bacteria Are Everywhere!
Students are introduced to the concept of engineering biological organisms and studying their growth to be able to identify periods of fast and slow growth. They learn that bacteria are found everywhere, including on the surfaces of our hands. Student groups study three different conditions under which bacteria are found and compare the growth of the individual bacteria from each source. In addition to monitoring the quantity of bacteria from differ conditions, they record the growth of bacteria over time, which is an excellent tool to study binary fission and the reproduction of unicellular organisms.
Figure 1. These colorful bacterial colonies were grown from bacteria present on human hands.Copyright 2012 Jasmin Hume, Polytechnic Institute of NYU
The word bacteria often brings up negative connotations related to illness and disease. However, many bacteria are beneficial to humans and useful (even essential), as well. Biological, environmental and biochemical engineers must have a thorough understanding of bacteria in order to use these organisms in devising new treatments for diseases, better oil spill clean-up, and the production of alternative energy forms. Biochemical engineers genetically modify the DNA in bacteria to produce "designer proteins," and proteins to treat diseases, such as cancer or to act as new materials enabling the conversion of solar energy to useable electricity. Bacteria are also used by environmental engineers as an ecologically-friendly way to digest (literally, to eat) the carbohydrates in oil from off-shore oil spills. Knowledge of the growth rates of bacteria is essential for these types of engineers in order to use the microorganisms in valuable ways for human and ecological life.
After this activity, students should be able to:
- Describe the potential positive and negative roles bacteria play in our lives.
- Determine, based on data analysis, the best way to keep bacteria off our hands.
- Plot data and determine their significance.
- Explain generally where bacteria can be found.
- Describe the conditions and requirements that bacteria need to survive.