Methanogens are a diverse group of archaea that can be found in various anoxic habitats. They are mostly anaerobic organisms that cannot function under aerobic conditions. Methanogens produce methane from substrates such as H2/CO2, acetate, formate, methanol and methylamines by a process called methanogenesis. They are found in habitats associated with decomposition of organic matter like bogs, anaerobic digestors, aquatic sediments, hydrothermal submarine vents and geothermal springs.

1. Ms Saajida Sultaana Mahusook
METHANOGENS

2.  Methanogens are a relative diverse group of archaea and
prokaryotic organisms that can be found in various anoxic
habitats.
 Methanogenic archaea are a very diverse group and some
strains can grow under extreme conditions, like extremely
high or low temperatures, high osmolarities or pH values.
 Methanogens are coccoid (spherical shaped) or bacilli (rod
shaped).
 There are over 50 described species of methanogens,
which do not form a monophyletic group, although all
methanogens belong to archaea.
 They are mostly anaerobic organisms that cannot function
under aerobic conditions.

3.  Methanogens lack peptidoglycan, a polymer that is found
in the cell walls of the Bacteria. Some methanogens have
a cell wall that is composed of pseudopeptidoglycan.
 Other methanogens do not, but have at least
one paracrystalline array (S-layer) made up
of proteins that fit together like a jigsaw puzzle.
 Methanogenic bacteria are considered a critical group of
bacteria, because of their phylogenetic diversity and the
only producers of a hydrocarbon, methane. They require
anoxic and highly reduced conditions for growth.
 These bacteria use CO2 or a methyl group as the terminal
electron acceptor and produce methane as their catabolic
end product.

4. Habitat:
 They are found in diverse habitats which are associated
with decomposition of organic matter, bogs, anaerobic
digestors, aquatic sediments, hydrothermal submarine
vents and geothermal springs.
 In animals, they are found in rumens of herbivores,
mammalian intestines, human oral cavity, guts of insects.

5.  Methanogens produce methane from substrates such as
H2/CO2, acetate, formate, methanol and methylamines by
a process called methanogenesis.
CO2 + 4H2 → CH4 + 2H2O
Example: Methanobacterium bryantii, Methanococcus
deltae
Application:
Methane production, biogas production, waste water
treatment

6. Reference:
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5754280/
 https://pdfs.semanticscholar.org/71ca/a52b089baeb8806ac
41049f43bec25065385.pdf

7. THANK YOU