1. To investigate the effect of different antibiotics on bacteria
2. To develop problem solving and experimental skills, for example, information is accurately processed and presented, experimental procedures are planned, designed and evaluated properly, producing valid results, recording results, and valid conclusion is drawn.
3. To develop the aseptic techniques for preparing agar plates and bacterial culture.
Do antibiotics have the same effect on killing different types of bacteria?
The main objective of this experiment is to investigate the effect of different types of antibiotics on bacteria Bacillus subtilis and Escherichia coli. Some of the main methods used in this experiment includes: the using of aseptic techniques for the preparation of agar plates. Paper discs containing different types of antibiotics then placed on the hardened agar plates. The inhibition zones of the bacteria on agar plates then is observed after 24 hours to determine the effectiveness of different types of antibiotics. The main result of this experiment is that the paper dics soaked with tetracycline has the greatest zone of inhibition in both Bacillus subtilis and E. Coli agar plates. Therefore, from this experiment, we can conclude that Tetracycline is the most effective antibiotics for Bacillus subtilis and E. Coli.
Antibiotics are among the frequently prescribed medicine for treating bacterial infection. Finishing antibiotics is important to prevent remaining bacteria from developing resistance to the antibiotics. However, antibiotics are useless to treat diseases causing by viruses such as colds, flu, coughs, and bronchitis. (emedicinehealth, 2010). Some antimicrobial actions on bacteria include (Fullick, 2009):
1. Interrupting metabolic pathways of bacteria such as blocking nucleic acid synthesis
2. Preventing the formation of cross-linking in the cell wall
3. Damaging the cell membranes of bacteria
4. Preventing the transcription or translation of microbial genes (mechanism for tetracyclines)
5. Stopping the bacterial DNA from coiling up
Examples of antibiotics that are commonly used in infection treatment include: gentamycin, tetracycline, streptomycin, and carbenicillin
Bacillus subtilis is rod-shaped and has the ability to form a tough, protective endospore, allow the organism to tolerate extreme conditions. Some uses of Bacillus subtilis includes using as a model organism for laboratory studies. It can also be genetically modified to convert explosives into harmless compound of nitrogen, water and carbon dioxide. (Wikipedia, 2010)
A close up view of B. subtilis bacterium. Source: http://en.wikipedia.org/wiki/Bacillus_subtilis
Escherichia coli are commonly found in lower intestine of warm blooded animals. Most E. coli are harmless. The bacteria can be grown easily and its genetics are relatively simple and easy to study,...