Question

Which bacterium is capable of utilising the most abundantly available gas in the atmosphere for one of their metabolic pathways, but cannot utilise the second most abundantly available gas for another metabolic pathway?

• A. Pseudomonas
• B. Clostridium
• C. Rhodomicrobium
• D. Xanthomonas

Answer 1

The correct option is C Rhodomicrobium

Nitrogen is the most abundant while oxygen is the second most abundant gas in the atmosphere.

Rhodomicrobium is an anaerobic Nitrogen-fixing bacteria and hence can use nitrogen but not oxygen.

Xanthomonas and Pseudomonas are aerobic bacteria and use oxygen.

Clostridium is anaerobic bacteria but cannot fix nitrogen.

So the correct answer is 'Rhodomicrobium'.