Anaerobic environment,hungate technique,microbes involved in 4 stages aidogenesis,acetogenesis,methanogenesis

1. BY SREEREMYA.S

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

9. REDOX POTENTIAL