Methanogens
- 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
- 7. THANK YOU