Day 3 - Suffocating.... Not Really

Anaerobic bacteria - no oxygen required!  We tried culturing our bacteria in anaerobic conditions to see if our bacteria can survive without oxygen.  We did this through two experiments.

Anaerobic experiment 1: Thioglycollate Broth



Materials:
Thioglycollate broth tube
Broth of our unkown bacterial culture


Steps:
1.  Aseptic transfer from our culture to inoculate the thioglycollate broth.

2.  Incubate at 37 degrees Celsius for 24 hours.







Results:  We can see the bacteria throughout the whole tube.  When we swirl the tube, we see the bacteria swirling.

 

 

Discussion:  Our bacteria proliferated in the anaerobic conditions, so our bacteria is facultative anaerobic.  This means that it can grow in aerobic or anaerobic conditions, as the situation demands.




Anaerobic experiment 2: GasPak Anaerobic System

Materials:
Anaerobic jar with lid and screw clamp
GasPak envelope
GasPak anaerobic indicator strip
Agar plates, inoculated with our unknown bacteria

Steps:
1.  Place the inoculated agar plates upside down in the anaerobic jar.


2.  Open GasPak envelopes and place the contents inside the jar.  The contents of the envelopes get rid of the oxygen and produce carbon dioxide.


3.  Open indicator packet strip and place it in the jar so that it is visible.  The indicator strip is blue in the presence of oxygen and clear in the absence of oxygen.


4.  Screw the lid on very tightly, and tighten the clamp.

5.  Incubate at 35 degrees for 24-48 hours.


Results:


Discussion:  Our bacteria grew in the absence of oxygen, and thus it is facultative anaerobic.  This means that our bacteria can grow in aerobic or anaerobic conditions, as the situation demands.