Question

Bacteria which are found in marshy areas and among the flora of cattle rumen are called
A. Acidophiles
B. Thermophiles
C. Methanogens
D. Thermoacidophiles

Answer 1

Hint: Nowadays production of methane is a concern worldwide due to its contribution to the accumulation in greenhouse gases in the atmosphere. The methane is produced through enteric fermentation. It is also produced in the gut of the rumen and hindgut in the Archaea.

Complete answer:
Lets us try to answer of this by discussing each option one by one –

Option A: Acidophiles – These organisms thrive under the highly acidic conditions usually at pH 2.0 or below. They are found in Archaea, Eukarya and bacteria. These organisms evolved most efficient mechanisms by which they pump the protons out the intracellular space so that to keep the cytoplasm at or near the neutral pH.
Option B: Thermophiles-As the name suggests, thermo means heat or temperature. So these are those organisms which thrive under the extremely high temperature (). Several thermophiles are Archaea. These organisms are found in the heated region of the earth such as a deep-sea vent, decaying matter of the plants like peat bogs and compost.
Option C: Methanogens- these microorganisms are responsible for the production of the methane as the by-product of the hypoxic condition. They belong to the Archaea. They are commonly found in wetlands and marshy areas in such places they are responsible for marsh gas. They are also found in the rumen of the ruminant animals and also in other animals. They are responsible for the belching in ruminants and flatulence in humans.
Option D: Thermoacidophiles- these microorganisms are both thermophilic and acidophilic. They can grow under high temperature as well as under low pH. Majorly they are Archaea or bacteria. They are found in the solfataric and hot spring environment. They can also be present in polluted conditions such as acid mine drainage.

Hence, the correct answer is option (C).

Note: Methanogens oxidise the carbon dioxide and produce methane as the waste product in their cellular respiration. They are anaerobic and obligate archaebacteria. They are found in the gut of marshes, cattle rumen, sludge of sewage, etc. As they are present in the gut of ruminants such as cows, they help to produce biogas from the dung of these animals.