Q.What is Capnophilic bacterium ?

Bacteria — Nutritional and Respiratory Types

Bacteria are the most metabolically versatile organisms on Earth. To make sense of that diversity, we classify them in two independent ways: how they obtain energy and carbon (nutrition), and how they relate to oxygen (respiration). Keeping these two questions separate is the key to the whole topic.

Nutritional types — where does the carbon and energy come from?

• Autotrophic bacteria make their own organic food.
  • Photoautotrophs use light energy (e.g. cyanobacteria).
  • Chemoautotrophs obtain energy by oxidising inorganic chemicals such as ammonia, nitrite or sulphur (e.g. nitrifying bacteria).
• Heterotrophic bacteria depend on ready-made organic matter.
  • Saprotrophs feed on dead organic material (major decomposers).
  • Parasites live in or on a host and often cause disease.
  • Many are symbionts, living in mutual benefit with a host.

Respiratory types — the relationship with oxygen

This is a different axis entirely — it asks whether the bacterium needs, tolerates, or is harmed by oxygen: