Which of the following statements is true about Escherichia coli?

a. E. coli cannot survive in anaerobic conditions.

b. E. coli cannot survive in aerobic conditions.

c. In anaerobic conditions, it will undergo respiration; in aerobic conditions, it will undergo fermentation.

d. In aerobic conditions, it will undergo respiration; in anaerobic conditions, it will undergo fermentation.

Ans.

Escherichia coli is a facultative anaerobic, gram-positive bacterium that can survive in absence or presence of oxygen. When oxygen is available in its surrounding, it shows respiration, in which complete breakdown of glucose takes place to produce energy. However, in the absence of oxygen, it shows fermentation for energy generation.

Hence, the correct answer is 'option d). in aerobic conditions, it will show respiration, and in anaerobic conditions, it will show fermentation.'