Answer :
Answer:
The answer is b)Betaproteobacteria and e)Gammaproteobacteria
Explanation:
Nitrification, which is defined as the microbial oxidation of ammonia to form a nitrate, plays an important role in the global nitrogen cycle. There are two different groups of bacteria that can oxidize ammonia, as a first step in the nitrogen cycle. These groups are known as the Beta-proteobacteria (genera Nitrosomonas and Nitrosaspira) and the Gamma-proteobacteria (genus Nitrosococcus).