Zusammenfassung der Ressource
Aerobic and Anaerobic
Microorganisms
- Anaerobic
- 3 Groups
- Obligate anaerobes
- Descriptions of oxygen requirements:
Require the ABSENCE of free O2.
Molecules other than O2 act as the final
electron acceptor.
- The presence of O2 leads to formation of toxic
metabolic end products, (e.g. superoxide)
- Example: Actinomyces, Bacteroides, Clostridium,
- Aerotolerant anaerobe
- Descriptions of oxygen
requirements: Do not use
O2 as a final electron
acceptor.
- They produce catalase and/or superoxide
dismutase, thus are not killed by the presence of
O2.
- Example: Lactobacillus,
Enterococcus, Listeria
- Facultative anaerobe
- Descriptions of oxygen requirements: Can grow in the presence or absence of free O2.
- Preferentially use O2 for aerobic respiration.
- In O2-poor environment, ananerobic respiration occur.
They utilize compounds (e.g. nitrates or sulfates) as final
hydrogen acceptors.
- Example: Staphylococci, Streptococci.
- Definition: Any organism that does not require oxygen
for growth. It may react negatively or even
die if oxygen is present.
- Aerobic
- 2 Groups
- Aerobes
- Descriptions of oxygen requirements:
Requires O2 as the final electron acceptor in
the complete oxidative degradation.
- Example: Bacilli, Pseudomonas
- Microaerophiles
- Descriptions of oxygen requirements:
Require limited amount of O2 for growth.
- O2 in excess will block the activities of
their oxidative enzymes and and results in death.
- Example: Legoinalla, Campylobacter
- Definition: Is an organism that can survive
and grow in an oxygenated environment.