An organism is discovered that thrives in both the presence and absence of oxygen. Interestingly, as oxygen is removed from the
organism's environment, the rate of sugar consumption increases while the growth rate decreases. What do these observations suggest about the likely identity of this organism?
This organism makes ATP (energy provider molecule) by aerobic respiration in presence of oxygen, but when oxygen is removed it is capable of switching to fermentation (sugar consumption increases and growth rate decreases).
This happens because fermentation is much less effective at producing ATP and therefore there is not enough energy for growth.
This organisms are called facultative anaerobic.
Organisms with this type of metabolism include bacteria like Escherichia coli and Salmonella or yeast like Saccharomyces cerevisiae.
This zone is called as the zone of aeration. It is present between the earth's surface and the water table, and its main constituents are the soil and rocks. The pores which are present in this zone are partly filled with water, and may mix up with air, causing aeration.
