4. Also microaerophiles like Campylobacter jejuni very
important in medial terms
For proper diagnosis and for studies of anaerobic
environments culture techniques are desirable
5. Culture of anaerobes is extremely difficult due to the
need to exclude oxygen, slow growth and complex
growth requirements
Molecular methods based on DNA analysis and direct
microscopy have shown that we are largely ignorant of
the microbial world and previously unknown diversity
has been discovered
6. Culture methods
Anaerobes differ in their sensitivity to oxygen and the
culture methods employed reflect this - some are
simple and suitable for less sensitive organisms, others
more complex but necessary for fastidious anaerobes
Vessels filled to the top with culture medium can be
used for organisms not too sensitive
7. Most common adaptation of media is the addition of a
reducing agent, e.g. thioglycollate, cysteine
Acts to reduce the oxygen to water, brings down the
redox potential -300mV or less.
Can add a redox indicator such as rezazurin, pink in
the presence of oyxgen - colourless in its absence
8. Deep culture tubes can be used to test whether an
unknown organism is anaerobic/facultative or aerobic
Thioglycollate added to culture medium, oxygen only
found near top where it can diffuse from air -pattern
of colony formation characteristic of organisms