Antimicrobial properties of mint and garlic CPAC Olivia Benny
Aim: to investigate the antimicrobial properties of mint and garlic
Independent variables The independent variable is the
variable which is changed and in this
experiment the independant variable is
the mint and garlic as we are
investigating the different effects on
the bacteria from the mint and garlic
as they both have different microbial
properties
Dependant variables The dependent variable is the
variable measured which is the zone of
inhibition, the zone of inhibition will
vary depending on the mint or garlic
used
Control variables One control variable is o use the
same bacteria for each sub practical in
order to collect accurate results as he
results may vary depending on
different bacteria e.g. the mint may
work better on the E coli vs another
bacterial, to control his variable I have
used the same bacteria (E-Coli)
Another variable I have controlled
is the temperature a which is the agar
is incubated in as temperature can
affect the ability for the mint and
garlic to work as antimicrobial
properties and therefore valid results
may not be obtained, to control his I
have incubated the agar in a water bath
over night with the same temperature.
The volume of plant material
when adding onto the paper discs is
kept the same as a larger volume of
plant material may provide a larger
zone of inhibition, I have controlled
this variable by using a pipette
ensuring the same volume (0.1cm^3)
is used every time
Results:
Group Garlic – zone of Mint – zone of inhibition Control: distilled water
inhibition (cm) (cm) – zone of inhibition (cm)
1 1.90 0.82 0.07
2 2.43 1.08 0.14
3 2.29 1.28 0.11
4 1.90 3.95 0.02
5 1.70 0.69 0.04
Average 2.04 1.56 0.08
Aim: to investigate the antimicrobial properties of mint and garlic
Independent variables The independent variable is the
variable which is changed and in this
experiment the independant variable is
the mint and garlic as we are
investigating the different effects on
the bacteria from the mint and garlic
as they both have different microbial
properties
Dependant variables The dependent variable is the
variable measured which is the zone of
inhibition, the zone of inhibition will
vary depending on the mint or garlic
used
Control variables One control variable is o use the
same bacteria for each sub practical in
order to collect accurate results as he
results may vary depending on
different bacteria e.g. the mint may
work better on the E coli vs another
bacterial, to control his variable I have
used the same bacteria (E-Coli)
Another variable I have controlled
is the temperature a which is the agar
is incubated in as temperature can
affect the ability for the mint and
garlic to work as antimicrobial
properties and therefore valid results
may not be obtained, to control his I
have incubated the agar in a water bath
over night with the same temperature.
The volume of plant material
when adding onto the paper discs is
kept the same as a larger volume of
plant material may provide a larger
zone of inhibition, I have controlled
this variable by using a pipette
ensuring the same volume (0.1cm^3)
is used every time
Results:
Group Garlic – zone of Mint – zone of inhibition Control: distilled water
inhibition (cm) (cm) – zone of inhibition (cm)
1 1.90 0.82 0.07
2 2.43 1.08 0.14
3 2.29 1.28 0.11
4 1.90 3.95 0.02
5 1.70 0.69 0.04
Average 2.04 1.56 0.08
