Question

A few organisms are known to grow and multiply at temperatures of 100-105°C. They belong to

(a) thermophilic sulphur bacteria

(b) hot spring blue-green algae

(c) methanogenic archaebacteria

(d) marine archaebacteria.

Answer 1

Option a is correct

Explanation: Thermoacidophiles (temperature and acid-loving) archaebacteria are found in hot sulfur springs. Although they are microscopic, single-celled organisms, they flourish under conditions which would kill higher organisms.

These are aerobic bacteria and have the capacity to oxidize sulphur to H₂S0₄ at high temperature and high acidity (pH = 2.0). Some of them are also able to reduce sulphur to H₂S under anaerobic conditions. As a rule, they grow best between 80° and 100°C and several species do not grow below 80°C.