Question

Some hyperthermophilic organisms, that grow in highly acidic (pH = 2) habitats, belong to the two groups which are

• A. Liverworts and yeasts
• B. Eubacteria and archaea
• C. Cyanobacteria and diatoms
• D. Protists and mosses

Answer 1

Answer: (B)

Eubacteria and archaea

Many thermophiles are archaea, while thermophilic eubacteria are suggested to have been among the earliest bacteria. Many of these require elemental sulfur for growth. Some are anaerobes, that use the sulfur as an electron acceptor during cellular respiration. Some are lithotrophs, that oxidize sulfur to sulfuric acid, thus requiring the microorganism to be adapted to very low pH as well. These organisms are inhabitants of hot, sulfur-rich environments such as hot springs and geysers etc.