Is E. coli anaerobe or aerobe?

Escherichia coli (E. coli) can be classified as a facultative anaerobe. This means that although E. coli can survive in the presence of oxygen (aerobic conditions), it can also survive in the absence of oxygen (anaerobic conditions). Under aerobic conditions, E. coli carries out cellular respiration, a process that uses oxygen to break down organic compounds and generate energy. When oxygen is not present, E. coli can switch to fermentation, a process that breaks down organic compounds without using oxygen, generating energy in the form of ATP. As a facultative anaerobe, E. coli can adapt to different environments and utilize the most efficient energy-producing pathway available.