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The living organisms that we cannot see with our naked eyes are called microorganisms. These microorganisms are also known as microbes. Example: Bacteria, fungi, algae, and protozoa.
*viruses are also considered as microorganisms but they are completely different from others. They become active only when they get inside host (someone’s body)
There are two types of microorganisms (based on number of cell)
Where do microorganisms are found?
Microorganisms are found everywhere from cold region to hot region and dry region to wet region. Even these microbes are found in our house but since they are so small, we cannot see them.
There are two types of microbes
Friendly microbes are very useful for us. They help us in different ways, which are as follows:
Lactobacillus is the bacterium that is present in the milk. They multiply and convert the milk into curd.
Yeast is used in bakery industry to make bread, cake, and pastries. Yeast produces carbon dioxide, which make dough fluffy.
*Fermentation: The conversion of sugar into alcohol is called fermentation.
Microbes such as bacteria and fungi are used to produce medicines. These medicines are called antibiotics. Antibiotics stop the growth of bacteria in our body and help us fight with them.
These antibiotics are also mixed with the food of animals so that they can stay safe from diseases.
Some of the popularly known antibiotics are penicillin, streptomycin, and erythromycin.
What is a vaccine?
Vaccines are the medicines that are produced with the help of viruses. These vaccines when injected in body create antibodies over a period so that whenever the same virus attacks our body it is terminated.
Vaccination
The process of giving vaccine is called vaccination.
The bacteria such Rhizobium increases the fertility of soil by converting the nitrogen into its compounds so that plants can use them. This process is called nitrogen fixation.
Some bacteria help in cleaning the environment by decomposing the waste materials such as vegetable peels, leaves, natural fabric, dead animals etc.
There are many microbes that can cause disease in both humans and animals. These microbes are called pathogens.
Types of diseases caused by microbes in humans
There are two types of diseases:
Communicable diseases are the disease that transfers from an unhealthy person to healthy person via water, air, and food. Example: small pox and common cold.
Non-communicable diseases are the disease that does not transfer from an unhealthy person to healthy person. Example: parkinson’s diseases and heart diseases.
What are carriers?
Carriers are the insects and animals that carry some of the dangerous bacteria or virus in their body. Example: Female anopheles mosquitoe is the carrier of parasite that causes malaria in humans.
Many bacteria cause diseases in animals. One such disease is anthrax.
Many microbes cause diseases in plants such as wheat, potato, and rice. These microbes reduce the yield of crops. Spraying some chemical can prevent the growth of microbes in plant.
What is food poisoning?
The illness caused due to eating some spoilt food is called food poisoning.
How food is spoiled?
When the food is left in an open place, some bacteria may grow on it. These bacteria release toxic substances that spoil the food.
It is very important to prevent our food from bacterial growth. Some of the best preventive methods are as follows:
Common salt is used to prevent food item such as amla and raw mangoes.
Sugar is used to prevent food items like jam and jellies.
Oil and vinegar is used to prevent pickles, fish, and meat.
Heating and cooling treatment is done for the milk. The milk is first heated upto 700C for at least 1 minute. After that, it is cooled and stored in the container. This method of preventing milk is called pasteurisation.
Dry fruits and vegetable are packed and stored in our houses for long term prevention.
The process through which the nitrogen is replenished in the soil and from soil, it is sent back to the atmosphere is called nitrogen cycle.
