Microorganisms: Friend And Foe

Any entity that possesses characteristics of life such as the ability to reproduce, respond to environmental stimuli, constitutes a living organism. Furthermore, living organisms need sustenance to survive, hence they need to eat. Also, movement and mobility is a crucial aspect of an organism if it needs to acquire food.

Most organisms are visible to us. But some living organisms are extremely small, so a microscope is required to view them. These organisms are known as microbes or microorganisms and are single-celled or unicellular. They exist in nature in almost every habitat. They are ubiquitous.

Microorganisms are crucial in maintaining a balance in our ecological system. They live around us and inside us. They maintain the health of organisms and help clean up our environment. They help produce different foods too.

While microorganisms have tons of benefits they can be harmful and cause deadly diseases too. For example, we see fungus growing on bread when left unused for a couple of days. This is because bread is moist, making it one of the most favourable conditions for the breeding of microbes.

Classification of Microorganism

Microbes are categorized into four major groups:

• Bacteria

• Fungi

• Algae

• Protozoa

Viruses, on the other hand, are microscopic but differ from microbes. Differ in their reproduction aspects, as they reproduce only in the cells of their hosts. These host organisms can be of animals, bacteria or even plants for that matter. A virus is typically coated by protein and has a nucleic acid molecule.

Useful Microorganisms

Following are a few examples of useful microorganisms:

• Extensively used in the baking industry to make cakes, bread, pastry etc.

• Used in the production of milk products. Example: Lactobacillus bacteria is used in the formation of curd from milk

• Since ages, microbes are being used in the production of alcohol

• It is also used to make organic acids. Acids such as citric acid, lactic acid, fumaric acid, gluconic acids are made using microbial activity

• Used in the production of steroids

• Antibiotics are produced using microorganisms

• Used in the production of vitamins: Vitamins such as Vitamin B complex, Riboflavin is produced by Ashbya gossypii, Eremothecium ashbyii and Clostridium bytyricum. Ascorbic acid, also known as Vitamin C is produced by species of Acetobacter

• Microorganisms synthesize enzymes such as Lipase, Lactase, Amylase, Pectinase, Penicillinase.

• They increase the fertility of the soil and by fixing nitrogen

• Help in the treatment of sewage

• Extensively used to clean up our environment

• Used in pest control

Harmful Microorganisms

• The microorganisms that cause diseases in living beings are known as pathogens.

• The pathogens can enter our bodies through air, water and food.

• Some pathogens are transmitted directly from an infected person.

• The diseases which are transmitted by an infected person directly or indirectly are known as communicable diseases. For eg., common cold, tuberculosis, etc.

• Microorganisms also grow on food and spoil it. That is why preservatives are added in the food to prevent it from spoilage.

Diseases Caused By Microorganisms

Some diseases caused by microbes are:

Diseases Caused by Microorganisms in Animals

Diseases Caused by Microorganisms in Plants

Food Spoilage by Microorganisms

1. Food spoilage refers to the damage in the quality of food that makes it unsuitable for human consumption.
2. Bacteria, moulds, and yeast are the main causes of food spoilage.
3. Moulds spoil food with reduced water activity. For eg., dry cereals, cereal products.
4. These microbes produce certain enzymes that decompose the important constituents of food.
5. Bacteria, on the other hand, cause the spoilage of food with increased water activity. For eg., milk products.

Some Interesting Facts About Microbes

• Microbes can be fatal.

• Microbes in our gut cause change of mood.

• Dry hands have fewer bacteria than damp hands.

• The smallest known bacteria is the Mycoplasma.

• 50% of the oxygen we breathe come from microbes.

• Your belly button alone has more than 1400 bacteria.

• There are more than a billion microbes in a person’s mouth.

• 1.82kgs of your body’s weight constitutes the collective weight of microbes in your body.

This was just a brief about the microorganisms- its beneficial, harmful and few facts Stay tuned with BYJU’S Biology to learn more about microorganisms-friend and foe and other related topics.

Further Reading