Mint has been used for many centuries. The Japanese have distilled peppermint oil for several centuries and the oil is further treated to produce menthol. The smell of mint is known to keep mice away and pennyroyal is also regarded as an effective insecticidal against fleas and aphids. Mint is carminative, simulative, stomachic, diaphoretic and antispasmodic. Peppermint has the highest concentrations of menthol, while preparations of spearmint are often given to children. Mint is a general pick-me-up, good for colds, flu and fevers.
Turmeric is a very effective intestinal antiseptic. Turmeric is a mild digestive, being aromatic, a stimulant and a carminative. An ointment base on the spice is used as an antiseptic in Malaysia. Turmeric water is an Asian cosmetic applied to impart a golden glow to the complexion. Curcumin has been shown to be active against Staphlococcus aureus (pus-producing infections).
Hypothesis:
I predict that in this experiment the garlic will kill more bacteria that the mint and turmeric or any other plant.
Null Hypothesis:
The garlic will kill very little or no bacteria. Another plant will kill more bacteria within a radius than the garlic. Despite the fact that garlic does have some antibacterial properties it may not have the ability to kill all bacteria.
Relationship to biological principles:
This study can be related to biological principles because plants can run or hide so how would they protect themselves? To investigate we can study the antibacterial properties if they have any to see hoe effective this would be when confronted with the possibility of infection.
Apparatus:
- Agar plates seeded with bacteria
- Plant material
- Methylated sprit
- Sterile pipette
- Paper discs
- Sterile Petri dish
- Sterile forceps
- Incubator
Plan:
Pre-prepared agar plates would be seeded with bacteria. 3g of the chosen plant would be crushed with 10 cm of Methylated sprit. This is used to kill any bacteria. The mixture would have to shaken regularly.
0.1 of the extract would be pipetted onto the sterile paper and would be left to dry for 10 minutes on open sterile Petri dishes.
This would be repeated for the other 2 plants and a control of ethanol would also be used.
The Petri dish would then be taped shut to and would be left incubated for 24 hours at 25 C
The plates would then be observed and measurements would be taken.
Independent Variables:
The independent variable for this experiment is the type of plant that is used fro example mint, rosemary etc.
Dependent variable:
The dependent variable for this experiment is the diameter of the bacteria killed around plant. There was also a control variable which was ethanol.
Health and safety:
The risk in this type of experiment is very high due to the fact that a bacterium is being used. If exposed people can be infected to diseases and become ill. Therefore aseptic techniques are used. To prevent and minimise the risk of infection bench guard is to be used just in case some bacteria escape. For the same reason gloves would be used.
Results:
It is difficult to distinguish anomalous results because there is little data of the same species to compare it with. To ensure that the data is reliable a micrometer was use to measure small distances. Also all substances were pipetted.
Discussion:
From my results I can reject my null hypotheses and accept my hypothesis that the garlic would kill more bacteria than the other plants. This can clearly be seen from the results. Therefore it can be concluded that garlic has more antibacterial properties other plants therefore theoretically making it less susceptible to disease. Mint is used by millions every day kill bacteria and plaques on their teeth. However although mint tastes nice, it is not as effective at killing bacteria as garlic is. Therefore garlic is better as toothpaste and also an anti bacterial agent. However there is a disadvantage which is the smell.
