Suppose you are given unlabeled cultures of colonies of cyanobacteria and purple sulfur bacteria.How can you use an obligate aerobic eukaryotic organism to test which colonies are which?
A) Add the aerobe to each culture;cyanobacteria will be toxic to other organisms.
B) Add the aerobe to each culture;purple sulfur bacteria will be toxic to other organisms.
C) Add the aerobe to each culture;cyanobacteria will provide the required oxygen if allowed to photosynthesize.
D) Add the aerobe to each culture;purple sulfur bacteria will provide the required oxygen if allowed to photosynthesize.
E) The aerobe cannot be used to test which colonies are which.

Question

Quizplus · Accepted Answer

Cyanobacteria are capable of photosynthesis and produce oxygen as a byproduct. So when the aerobe is added to the culture, if cyanobacteria are present, they will produce oxygen through photosynthesis, which will be helpful for the aerobic eukaryotic organism. On the other hand, purple sulfur bacteria are photosynthetic bacteria, but they produce sulfur instead of oxygen. So the presence of the aerobe will not be helpful for them. Hence, by observing the growth of the aerobic eukaryotic organism, we can conclude that the culture contains cyanobacteria.

Suppose You Are Given Unlabeled Cultures of Colonies of Cyanobacteria