The document provides a comprehensive overview of methanogens, detailing their history, ecology, morphology, metabolism, and the pros and cons of methanogenesis. It highlights that methanogens, predominantly found in the domain Archaea, are crucial for methane production, which is significant for energy and has implications for global warming. The document also discusses the roles of methanogens in ruminants and their contributions to anthropogenic methane emissions.

1. METHANOGENS
By
KAUSHAL KUMAR SAHU
Assistant Professor (Ad Hoc)
Department of Biotechnology
Govt. Digvijay Autonomous P. G. College
Raj-Nandgaon ( C. G. )

2. OVERVIEW
 General introduction.
 History of methanogens
 Ecology and habitat of methanogens.
 Morphology of methanogens.
 Diversity found in methanogens.
 Characterstics of some model methanogens.
 Metabolism of methanogens:
 Methanogenesis
 Cofactors and coenzymes of methanogenesis
 Different pathways used during methanogenesis
 Energy conservation.
 Pros and cons of methanogens.
 Application
 References.

3.  Methanogenesis or biomethanation is the formation
of methane by microbes known as methanogens .
Organisms capable of producing methane have been
identified only from the domain Archaea , a group phylo
genetically distinct from both eukaryotes and bacteria ,
although many live in close association with anaerobic
bacteria. The production of methane is an important and
widespread form of microbial metabolism.
In anoxic environments, it is the final step in the
decomposition of biomass . Methanogenesis is responsible
for significant amounts of natural gas accumulations, the
remainder being thermogenic

5. HISTORY
 In 1776, Alessandro Volta -combustible air that was reported
to him by a friend, Father Carlo Campi on a little boat in Lake
Maggiore.
 In 1977, Carl Woese and Ralph
Wolfe resulted in the finding that the
methanogens were ‘only distantly
related to typical bacteria.
 Thus, the methanogens became the first known Archaea.
 They are now known to comprise five orders of the
Euryarchaeota: Methanococcales, Methanosarcinales ,
Methanobacteriales, Methanomicrobiales, and
Methanopyrales (Liu & Whitman, 2008).
Alessandro Volta

13. Natural occurrence
In ruminants
Testing Australian sheep for exhaled methane production (2001), CSIRO
Enteric fermentation occurs in the gut of some animals, especially ruminants. In
the rumen, anaerobic organisms, including methanogens , digest cellulose into
forms nutritious to the animal. Without these microorganisms, animals such as
cattle would not be able to consume grasses. The useful products of
methanogenesis are absorbed by the gut, but methane is released from the
animal mainly by belching (eructation). The average cow emits around 250 liters
of methane per day. In this way, ruminants contribute about 25% of
anthropogenic methane emissions. One method of methane production control
in ruminants is by feeding them 3-nitrooxypropanol.

14. Some humans produce flatus that contains methane. In one study of
the feces of nine adults, five of the samples contained archaea capable of
producing methane. Similar results are found in samples of gas obtained
from within the rectum.
Even among humans whose flatus does contain methane, the amount is in
the range of 10 % or less of the total amount of gas
In humans

16. In plants
Many experiments have suggested that leaf tissues of living plants emit
methane.Other research has indicated that the plants are not actually
generating methane; they are just absorbing methane from the soil and
then emitting it through their leaf tissues

18. Morphology of
Methanogens

19. MORPHOLOGY
 Methanogens are made primarily in two shapes, cocci and rods.
 Can also be found having a plate like structure.
 Several genera have walls with pseudomurein. Other walls
contain either proteins or heteropolysaccharides.

20. CHARACTERSTICS OF METHANOGENS

21. Pros & Cons of Methanogenesis

22. PROS OF METHANE PRODUCED BY
METHANOGENS
 Methanogenic archaEa are potentially of great
practical importance since methane is an excellent
energy source.
 Commercially used, in hotels, restaurants, motels,
small manufacturing units, commercial office
buildings, hospitals and schools mainly for cooking
and heating purposes.

23.  Natural gas can be used as a fuel for vehicles (cars,
trucks, jet engines). It is a cleaner, cheaper fuel than
diesel or gasoline.
 For many years sewage treatment plants have been
using the methane they produce as anaerobic digester
microbes that will degrade particulate wastes such as
sewage sludge to H₂, CO₂, and acetate.

24. CONS OF METHANE FORMATION
 Damage to Environment: Burning of natural gas
also releases compounds which are greenhouse gases
that cause global warming and climate changes.
 Toxic and Flammable: Leaks of natural gas are
tremendously dangerous. Such leaks may cause
explosions or fire. When inhaled, the gas is highly
toxic.

25. Conclusion
 Methanogens are obligate anaerobes.
 They are wide spread.
 They consume carbondioxide and hydrogen and produce
methane gas.
 they depend uponsyntrphy or when one organism lives
off of the products of another organism.
 Methane produced by them is benifical and they do
contibute in global warming.

26. REFERENCES