Heterotrophic Bacteria

Heterotrophic bacteria derive energy from organic compounds. They are widely distributed and most abundant forms. They may be aerobic or anaerobic. They are omnipresent and found in the food, soil, water. They help in recycling of natural substances.

They are mostly responsible for the decomposition of organic matter. They also live as a parasite and cause various diseases in plants, animals and humans. They are also present as a symbiont in organisms, e.g. Rhizobium in the root nodules of legumes, etc.

Bacteria are used for making curd, antibiotics, nitrogen-fixation, etc. Heterotrophic bacteria can decompose organic matter such as cellulose, keratin, lignin, chitin, etc.

What are the different types of Heterotrophic Bacteria?

According to their habitat, food source and association with other organisms, heterotrophic bacteria can be divided into three main categories:

  • Parasitic – They derive their food from living organisms
  • Saprophytic – They feed on dead and decaying organic matter
  • Symbiotic – They live in symbiotic association with other organisms.

Heterotrophic Bacteria Types and Examples

Parasitic Bacteria

Parasitic bacteria may be a parasite on animals or plants. Not all parasitic bacteria are pathogenic, e.g. microbial flora of the human body, present in skin, digestive tract, mucous membranes and other organs, coexist without harming.

Pathogenic heterotrophic bacteria are known to cause many diseases. They have different modes of infection and transmission. Some examples are:

In Plants

Citrus canker – Xanthomonas axonopodis

Crown gall – Agrobacterium tumefaciens

Blight of beans – Xanthomonas campestris

Wildfire of Tobacco – Pseudomonas syringae

Granville wilt – Pseudomonas solanacearum

In Humans

Cholera – Vibrio cholerae

Typhoid – Salmonella typhi

Tetanus – Clostridium tetani

Whooping cough – Bordetella pertussis

Lyme disease – Borrelia

Diphtheria – Corynebacterium diphtheriae

Diarrhoea – Escherichia coli

Tuberculosis – Mycobacterium tuberculosis

Gonorrhoea – Neisseria gonorrhoeae

Symbiotic Bacteria

Rhizobium present in root nodules of legumes is a common example of symbiotic bacteria. Bacteria present in the gut of humans and ruminants help in digesting food. They also help in producing vitamins.

Saprophytic Bacteria

They are the main decomposers of the food chain with fungi. They break down complex organic matter to simple compounds and assimilate them. They help in nutrient recycling. They decompose dead and decaying plants and animal remnants and help in biodegradation.

This was all about Heterotrophic Bacteria. Explore notes on Autotrophic Bacteria and other important concepts related to NEET, only at BYJU’S.

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