Civil War Outcome

Antibiotics
Vs
Tea Tree Oil

To determine the effect of various different antibiotics and Tea Tree oil on the Bacillus subtillis different types of bacteria. I will test six antibiotics and the Tea Tree oil on Bacillus subtilis. I will test tetracycline, chloramphenicol, ampicillin, sulphatriad, penicillin G and Streptomycin. I would also like to see if Bacillus subtillis shows resistance to Antibiotics or to Tea Tree oil. The use of penicillin is being reduced because of the resistance many types of bacteria are developing against it.

Hypothesis: My hypothesis is that penicillin will inhibit the most growth against Bacillus subtilis. Tea Tree oil will not be as effective as the antibiotics, but may inhibit a small amount of growth against Bacillus Subtilis.

Rationale: I feel that this experiment is valid because it shows how different antibiotics react to different types of bacteria. It also points out the fact that not all antibiotics work the same or that they work at all on all types of bacteria.

Equipment: * 3 agar plates * Blank discs * Antibiotic assay disc * Culture of Bacillus subtilis * Forceps * Bunsen Burner * Inoculating loop * Tea Tree oil * Heat Mat

Method: First Agar Plate * Sterilise inoculating loop using Bunsen burner, allow inoculating loop to cool before using inoculating loop to pick up, the liquid of the culture. * Agar plate to be open as little as possible, minimising possible access by bacteria from the air. * Using edge of inoculating loop move gently over surface of agar in a sweeping motion. * Place Antibiotic assay disc on top of the culture that has been spread on agar. * Seal agar plate with tape to guard against the possibility of anaerobic organisms growing due to lack of air. * Agar plate containing culture and antibiotic is then to be incubated at a fixed temperature (usually 37°C - human body temperature) for 2-3 days.

Second Agar plate * Sterilise inoculating loop using Bunsen burner, allow inoculating loop to cool before using inoculating loop to pick up, the liquid of the culture. * Agar plate to be open as little as possible, minimising possible access by bacteria from the air. * Using edge of inoculating loop move gently over surface of agar in a sweeping motion. * Sterilise forceps, once cooled down use forceps to pick up blank disc that has to be swab by Tea Tree oil before putting it in to agar plate that has the culture. * Once discs are swabbed by Tea Tree oil, spread a few disc on agar that is containing the culture to redeem results. * Seal agar with tape to prevent possible access by bacteria from air. * Agar plate containing culture and antibiotic is then to be incubated at a fixed temperature (usually 37°C - human body temperature) for 2-3 days.

Third Agar plate
Used as control * Sterilise inoculating loop using Bunsen burner, allow cooling down. * Use inoculating loop to pick up liquid from culture. * Use edge of inoculation loop gently over surface of agar in a sweeping motion. * Seal agar with tape. * Agar plate then to be incubated at a temperature (usually 37°C - human body temperature) for 2-3 days.

Risk assessment:

Risk | Precaution | Burn from using Bunsen Burner | Tie hair back, be cautious with flame safely, use “mat heat”, to prevent slide of Bunsen burner and safety from flame. | Contamination from microbes spilling | Plates are sealed, washing hand, cleaning up spill. Always take plate with you. |

Results and Observation:
6 Antibiotics used in one agar plate with culture.
6 Disc contained with Tea Tree oil by swabbing it, is in one agar plate.
1 extra agar plate for control.
Total of Agar Plates are three.

Discussion:
Antibiotic inhibits more growth of the culture, although there are some antibiotic which is resistance to the culture. Tea tree oil is not as effective as antibiotic; it shows light circulations but no signs of microorganism’s growth. The outcome of the control shows no signs of growth of colonies from the culture.
Bacteria can be cultured or grown on nutrient agar. Nutrient agar is a jelly like substance extracted from sea weed to which nutrients have been added so that bacteria or other microorganisms can be grown on it. If conditions are favourable bacteria will rapidly reproduce by dividing in two. Eventually bacterial reproduction produces spots on the nutrient agar each of which consists of the many descendants of a single bacterium.
These spots which are visible to the unaided eyes are called colonies.