The organisms which are not visible to the naked eye are called microorganisms
Microorganisms are found in abundance in the soil, water and air.
There are five kinds of microbes. Bacteria, Algae, Fungi, Protozoa and Viruses
The discovery of microscopes enabled scientists to observe and stu...
● Organisms which aren't visible to our naked eyes are called
microorganisms/microbes.
● Microbes can be as small as 0.00001 mm.
● The study of microbes is called microbiology
( Micro - small, bios - life, logos - study ).
● Microbes are found everywhere.
● They have a hard outer covering called cyst to protect them from harsh conditions.
● in 1677, Anton van Leewenhoek, a Dutchman, was looking at a drop of pond water
under a microscope and found tiny moving organisms in it he called them
microorganisms.
● Bacteria are unicellular prokaryotic (doesn't have a well defined nucleus)
microorganisms.
Three types of bacteria are
● Coccus or round-shaped: The bacteria which have a spherical shape are called cocci
(Singular coccus, plural cocci). For example,Streptococcus
● Bacillus or rod-shaped: The bacteria which are rod-shaped are known as bacillus.
Bacillus typhosus.
, ● Spirullum or vibrio shaped: These bacteria are cork-screw (spiral) shaped or comma
shaped. For example, Vibrio cholerae.
USES OF BACTERIA
● Fixation of nitrogen: Rhizobium bacteria changes the nitrogen of air into nitrates.
These bacteria live in the nodules of roots in leguminous plants.
● Decay of plants & animal wastes: Bacteria breaks down the dead bodies of animals
and plants by feeding on them and produce humus which helps to maintain the fertility of
soil. They're also called decomposers and help in cleaning the environment.
● FOOD & BEVERAGES PRODUCTION: Curd contains Lactobacillus when a little curd
added to milk it multiplies and converts milk into curd
● Bacteria is also used in the production of coffee dea and cocoa beans
● DIGESTION IN ANIMALS: Escherichia coli intestines of human & herbivorous animals
where they help the digestion of food.
IN INDUSTRIES
● Helps to produce wine and vinegar
● Helps in making meat tender for tanning of skin to make leather.
● Helps in production of vitamins & antibiotics.
● Helps in production of chemicals and citric acid
HARMFUL BACTERIA
● Disease causing microbes are called Pathogens
● Harmful Bacteria are mostly parasites.
● .Both in animals & humans & plants.
● Example for humans (Harmful Bacteria): tuberculosis, typhoid, diphtheria, tetanus,
whooping cough, cholera and leprosy.
● Anthrax is a dangerous human or little Cattle caused by a Bacillus anthracis bacteria
● Anthrax spoils cooked food, fruits, vegetables and is responsible for curdling of milk.
● Food spoiled by bacteria creates foul smell and bad taste
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