Question

“Experiment 2- Fluid Thioglycollate Medium to Assess the Effect of Oxygen on Bacterial Growth”

“Table 2: Experiment 2 Results”

“Sample Location”	“Growth Location in FTM”	“Oxygen Category”
“Control”	No growth	N/A
“Skin”	Below surface growth and throughout agar	None
“Nose”	Slight surface growth	Facultative anaerobe
“Throat”	No growth	Strict anaerobe
“Shoe”	Below surface growth and throughout agar	Microaerophile

“Post-Lab Questions”

“3. Provide an explanation as to why bacteria from each location displayed its pattern of growth?”

Click here to enter text.

“4. Why is it important to pull the inoculating needle out of the FTM via the same path you inserted it?”

Click here to enter text.

“5. How would you explain the presence of bacterial growth in the control FTM tube?”

Click here to enter text.

Answer 1

3, bacteria from each location showed different paterns of growth according the oxygen concentration present in that location. bacteria has different requirements for oxygen. For ex- a facultative anaerobe grows in both aerobic and anaerobic conditions. Ex- E coli

An obligate anaerobe grows only in the absence of oxygen. oxygen is toxic to anaerobic bacreria.

Normal flora colonise in our body in different locations according to their optimal requirements.

4, the inoculating needle is taken out from the tube through the inoculating line . it is done in order to limit the oxygen supply .

5, Control tubes are tubes with no bacterial inoculation. If there is growth in control tube, then the whole experiment should be performed once again. Growth in control tubes is due to contamination.