GROUP 2:

Angga Fatchulloh A. (105090100111009)

Khairatul Insani F. (105090100111031)

Dharma Asih P. (105090101111009)

Lia Rachmawati (105090107111001)

Winda Rahayu (105090113111001)

The growth of every living creature needs sufficientnutrients and environmental conditions that support for thegrowth process, as well as microbes. There are severalfactors that can affect the growth of microbes, such as:temperature, humidity, osmotic pressure, light, pH, and AWnutrient. Antibiotic resistance is a bacteria that has a set ofways to adapt for environments that contain antibiotic.Resistance mecanism include mutations in bacteria,inhibition of the enzymatic activity of antibiotics, changes inproteins that are targets of antibiotics, changes in metabolicpathways and membrane permeability

Student lab can determine the effect of

hydrogen’s ion concentration on the growth

of microbes

Student lab can distinguish the nature of

microbes based on their oxygen needed

Student lab can determine the effect of

chemical compounds on the growth of

microbes

pH 5pH 3 pH 7 pH 9

Physiological pH

Flacon tube with 5 ml

bacteria culture isolates 24

hours

Inoculated into tubes of

glucose phenol red broth

pH indicator, four tubes

should each contain 1 ml

bacteria culture isolates

48 hours of incubation at

room temperature

Methods

Physiological oxygen

48 hours of incubation

at room temperature

Melt the nutrient agar by

steaming, cool to 45

degrees Celcius

Inoculated 0.1 ml bacteria

culture isolates into tubes

of nutrient agar

homogenization

Inoculated by spread plate

technique 0.1 ml bacteria

culture isolates into plate of

nutrient agar

Flacon tube with 0.9 ml

bacteria culture isolates 24

hours

48 hours of incubation

at room temperature

Resistance of antibiotic

Fixing four antibiotic discs

to plate of nutrient agar with

the use Laminar Air Flow

(LAF)

Results

Pict. 1. Tubes which contain of 5 ml Glucose-phenol red broth with power of

Hydrogen (pH) 3,5,7,9 before inoculation and incubation.

2a. 2b. 2c. 2d.

From the pictures above, we know that all of the tubes are shown positive reaction after

incubation by isolates. Pict: 2a. pH 3 2b. pH 5 2c. pH 7 2d. pH 9

Positive reactions: not only indicated by the color change on Glucose-phenol broth but

also can be the formation of a precipitate in the bottom of tube.

Colour after Inoculation Colour after Incubation Growth On pH

3 5 7 9 3 5 7 9 3 5 7 9

Yellow Yellow

orang

e Red Yellow yellow Dark orange Dark red - - + +

Yellow Yellow

orang

e Red Yellow orange Red DarkRed + + + +

Yellow Yellow

orang

e Red Yellow

slightly

turbid yellow

slightly turbid

red

slightly turbid

yellow, there are

deposits + + + +

Yellow Yellow

orang

e Red Yellow Yellow

slightly turbid

red turbid red - - + +

Yellow Yellow

orang

e Red

slightly

orange

orange in

surface

orange in

surface Orange + + + +

Yellow Yellow

orang

e Red Yellow turbid yellow turbid yellow Jingga - + + +

Yellow Yellow

orang

e Red Yellow turbid yellow Yellow Light Orange - + + +

Yellow Yellow

orang

e Red Yellow Yellow Light Orange Light Orange - - + +

Microbial

K2C1

K2C2

H1K2

H3K3

H4K2

Eschericia coli

Bacillus cereus

Salmonella sp.

Table 1. Result of pH’s Effect on Microbial Test

3a. 3b.

Pict. 3a.Tubes which contain of 10-15 ml Nutrient agar before inoculation

and 3b. After inoculation (growth of aerob bacteria)

Pict.4 positive reaction is indicated by clear zone

formation on the medium.

Cephazoline (+)

Kanamycin (+)

Chlorampenizol (+)

Erythromycin (+)

The growth of bacteria is affected by pH, oxygen

and chemicals

There are several kinds of microbial based on

their need for oxygen: aerobic, facultative

anaerobes and obligate anaerobes

The effect of chemical compounds can inhibit the

growth of microbes

Thank you