When culturing a chemoorganoheterophic bacterium, what outcome is LEAST likely to occur if ammonia and phosphate are provided at equal concentrations?
A) Cells require much less P to grow than N, so extra P will be used for ATP synthesis and result in a faster growth rate.
B) Cells will never consume all of the phosphate, because N is needed in higher quantities than P.
C) The final biomass of cells will be no different than if only 50% of the phosphate was provided.
D) The bacteria will import all of the ammonia to use for biosynthetic pathways.

Question

Quizplus · Accepted Answer

Option A is the least likely to occur because it assumes that extra P will be used for ATP synthesis, which is unlikely because P is not the limiting factor in bacterial growth. Bacteria require a balanced ratio of N and P, and excess P does not promote growth. Option B is not correct because bacterial growth and consumption of N and P depend on the specific metabolic needs of the bacterium, so it is possible for all of the phosphate to be consumed. Option C is plausible because equal concentrations of N and P may meet the requirements for cell growth, and excess P may not lead to a significant increase in biomass. Option D is likely because ammonia is an essential nitrogen source for biosynthesis, and bacteria will import it as needed.

When Culturing a Chemoorganoheterophic Bacterium, What Outcome Is LEAST Likely