EVERYDAY SCIENCE

Detailed explanation-1: -An anaerobic organism is any organism that does not require oxygen for growth and even dies in its presence. Obligate anaerobes will die when exposed to atmospheric levels of oxygen. Facultative anaerobes can use oxygen when it is present.

Detailed explanation-2: -Facultative anaerobes are bacteria that can grow in both the presence or absence of oxygen. In addition to oxygen concentration, the oxygen reduction potential of the growth medium influences bacterial growth.

Detailed explanation-3: -Obligate anaerobes, which live only in the absence of oxygen, do not possess the defenses that make aerobic life possible and therefore cannot survive in air. The excited singlet oxygen molecule is very reactive. Therefore, superoxide must be removed for the cells to survive in the presence of oxygen.

Detailed explanation-4: -So, can facultative anaerobes survive with or without oxygen? It can be said, Yes! These organisms can survive with or without oxygen as these organisms have the capability to switch between an aerobic or anaerobic respiratory mode for the generation of energy.

Detailed explanation-5: -Facultative aerobes/facultative anaerobes can survive in both aerobic environments and anaerobic environments. Microaerophiles can tolerate low, but not atmospheric, amounts of oxygen.