examples of each type of aerobe/anaerobe

Key bacterial example of an obligate anaerobe

Clostridium botulinum (or Clostridium tetani); poisoned by atmospheric oxygen due to a lack of enzymes like catalase and superoxide dismutase to neutralize reactive oxygen species.

Key bacterial example of a facultative anaerobe

Escherichia coli; preferentially uses oxygen when present to produce ATP via aerobic respiration, but switches to fermentation or anaerobic respiration when oxygen is absent.

Key bacterial example of an aerotolerant anaerobe

Lactobacillus acidophilus (or Streptococcus pyogenes); solely carries out fermentative metabolism and does not utilize oxygen, but possesses mechanisms to tolerate and survive exposure to oxygen.

Key bacterial example of a microaerophile

Campylobacter jejuni (or Helicobacter pylori); requires low oxygen environments (typically $2\%$ to $10\%\,O_2$) for growth and is damaged by atmospheric concentrations of oxygen ($\approx 21\%\,O_2$).