Question

Is Azotobacter a non-photosynthetic bacterium?

Answer 1

Hint: Azotobacter is a free-living aerobic bacterium. It helps in nitrogen fixation. They are motile, spherical in shape and have a thick-walled cyst. They are found in soil, water.

Complete Answer: -
Bacteria are the prokaryotic organisms which have a cell wall made up of peptidoglycan. Some bacteria like cyanobacteria have chlorophyll and can prepare their own food. Some are chemoautotrophic and some are heterotrophic. For example, Azotobacter.
Azotobacter is the genus of free-living aerobic bacteria which are present in soil, water and also as symbiosis with the plants. These bacteria have the capacity for nitrogen fixation. These are non-photosynthetic organisms which are resistant to harsh environments due to the presence of cyst.
Plants need nitrogen for their growth and development. The free nitrogen in the atmosphere cannot be utilised directly by the plants. These bacteria convert the atmospheric nitrogen into usable forms which can be utilised by the plants. These organisms have the capacity of converting the free nitrogen in the atmosphere to ammonium salts which are easily absorbed by the plants.
The Azotobacter is extensively useful as it improves the fertility of the soil.The Azotobacter is economically important for producing food additives, biofertilizers, etc. It is used for the synthesis of phytohormones and also in bioremediation. It is used to produce a biofertilizer called Azotobacterin.

Hence, Azotobacter is non-photosynthetic.

Note: -
Rhizobium is another bacterium which has the capacity of nitrogen fixation. Unlike Azotobacter it is not free-living. Rather, it is found in association with the roots of leguminous plants. They are anaerobic.