Question

Questions 1. Why do we see growth of a strict aerobe along the stab line of an agar deep? 2. Where in an agar deep would you expect to find the lowest levels of oxygen? The highest? SSVVUOVOVOU 3. What is the role of oxygen in aerobic respiration? 4. Why do facultative anaerobes grow better in an aerobic environment than an anaerobic environment? 5. In an agar deep, how would you distinguish the growth pattern of an aerotolerant anaerobe from that of a facultative anaerobe? How can you distinguish between these two groups using the three growth conditions we set-up? References Brown, Alfred E. 2007. Benson's Microbiological Applications. Laboratory Manual in General Microbiolom 10th 11

Answer 1

Answer 1: If the microorganism is strictly aerobes it means it can only survive and grow in presence of oxygen so it always tries to grow at the place where oxygen supply is in high amount.So if we prepare the culture media and place them in a tube or in any petri plate so we see the highest amount of microorganism on the top portion of slab line or on outer surface due to high amount of oxygen presence there.

Answer: Lowest level of oxygen is present at Bottom of an agar deep while highest level of oxygen is present at the top portion on agar slab.

Answer 3: Aerobic respiration is a process where energy is released in the cell by breaking down of food substances only in the presence of oxygen.

Glucose + Oxygen------- Carbon dioxide + Water + Energy(used to make special molecule called as ATP)

So we can say that oxygen is required in aerobic respiration in order to break down food substances( Glucose) in order to release energy inside the cell which is needed to perform all cellular activities.

Answer 4: Facultative anaerobes are the organism which can grow better in presence of oxygen but in oxygen is absent so they can also grow in absence of oxygen. But it the condition is favourable (means there is availability of oxygen) so generally they grow in higher concentration there because as explained in above answer they can generate more amount of energy as ATP needed for cellular work in comparison to energy generatd in aerobic condition.