Question

Discuss autotrophic bacteria and heterotrophic bacteria.

Answer 1

Hint: Autotrophic nutrition is the mode of nutrition in which the preparation of food is on their own. It utilizes solar energy, carbon dioxide, and water. Autotrophic nutrition is derived from autotrophs. Heterotrophic nutrition is the nutrition in which an organism is unable to synthesize its food and depends on other sources such as plants and animals matter. Organisms performing heterotrophic nutrition are known as heterotrophs.

Complete answer:

Autotrophic bacteria	Heterotrophic bacteria
This type of bacteria synthesizes their food from inorganic substances such as carbon dioxide and hydrogen donors.	This type of bacteria do not synthesize their food but are dependent on other organisms or dead organic matter for food.
They are of two types i.e. photoautotrophic bacteria and chemoautotrophic bacteria.	They are of three types i.e. parasites, saprophytes and symbionts.
Photoautotrophic bacteria use solar energy for the synthesis of their food and are anaerobic.	Parasitic bacterias live on other organisms called the host and obtain their food from them.
Chemoautotrophic bacteria do not have photosynthetic pigment and utilize chemical energy to reduce carbon dioxide to organic food.	Saprophytic bacteria depend upon the dead or organic matters and are major decomposers in nature.
The bacteria can be purple or green due to the presence of their pigments.	Symbiosis lives in symbiotic association with other plants for mutual benefits.

Additional information: The symbiotic relationship performed by the symbiotic bacteria is for mutual benefits. Few species of rhizobium such as R. leguminosarum live in the root nodules of the leguminous plants and form an intimate symbiotic relationship. Photoautotrophs carry anoxygenic photosynthesis in which water is not used as reducing power. The purple color in the bacteria is due to the pigment called bacteriochlorophyll which is located in the membranes of thylakoids. The green color of the bacteria is due to the pigment bacteriopheophytin which is located inside small sacs called chlorosomes. The bacteriopheophytin is also known as chromium chlorophyll.

Note: Heterotrophic cells ingest biomass to obtain energy and nutrition. Autotrophs are capable of assimilating inorganic energy which is used to synthesize biochemicals. Aeromonas cause gastroenteritis which is a pathogenic condition and infection in the skin and lung. lactobacillus is a heterotrophic bacteria that is used in the production of curd from milk. Pseudomonas help in the decomposition and formation of humus.