In sewage-treatment systems, nitrifiers such as ________ are used to decrease the reduced nitrogen content.
A) Neisseria gonorrhoeae and N. meningitidis
B) Thiobacillus spp.
C) Nitrosomonas, Nitrosolobus, and Nitrosovibrio
D) Escherichia spp.
E) Helicobacter and Campylobacter

Question

Quizplus · Accepted Answer

Nitrosomonas, Nitrosolobus, and Nitrosovibrio are nitrifying bacteria that convert ammonia into nitrite, and then into nitrate, reducing the nitrogen content in sewage-treatment systems. Option A is incorrect as Neisseria gonorrhoeae and N. meningitidis are pathogenic bacteria that can cause gonorrhea and meningitis, respectively. Option B is incorrect because Thiobacillus spp. are sulfur-oxidizing bacteria and not involved in nitrification. Option D is incorrect as Escherichia spp. are not well-suited for use in sewage-treatment systems due to their pathogenic potential. Option E is incorrect as Helicobacter and Campylobacter are involved in causing various gastrointestinal diseases in humans.

In Sewage-Treatment Systems, Nitrifiers Such as ________ Are Used to Decrease