MICROORGANISMS- FRIENDS OR FOES

WHAT ARE MICROORGANISMS??

A microorganism  is a microscopic organism, which may be a SINGLE CELL^1] or MULTI CELLULAR ORGANISM The study of microorganisms is called microbiology, a subject that began with Antonie van Leeuwenhoek's discovery of microorganisms in 1675, using a microscope of his own design.

Microorganisms are very diverse and include all the bacteria ,viruses  and almost all the protozoans. They also include some members of the fungi and algae.

microorganisms -friends or foes??

Microorganisms play an important role in our lives. Some of them are beneficial in many ways whereas some 

others are harmful and cause diseases

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MICROORGANISMS AS FRIENDS

Commensals

Some microorganisms live inside our body. They help in certain functions of our bdoy systems. For example some bacteria in our gastrointestinal tract help in digestion. These type of organisms which reside in our body and are beneficial as well are called commensals.

Commercial Use of Microorganisms:

Microorganisms are used for the large scale production of alcohol, wine and acetic acid (vinegar). Yeast is used  for commecial production of alcohol and wine. For this purpose yeast is grown on natural sugars present in grains like barley, wheat, rice and crushed fruit juices, etc.                                                                                 

Medicinal Use of Microorganisms

Whenever we fall ill the doctor may give us some antibiotic tablets, capsules or injections such as of penicillin. The source of these medicines is microorganisms. These medicines kill or stop the growth of the disease-causing microorganisms. Such medicines are called antibiotics. These days a number of antibiotics are being produced from bacteria and fungi. Streptomycin, tetracycline and erythromycin are some of the commonly known antibiotics which are made from fungi and bacteria. The antibiotics are manufactured by growing specific microorganisms and are used to cure a variety of diseases. Antibiotics are even mixed with the feed of livestock and poultry to check microbial infection in animals. They are also used to control many plant diseases.

Vaccine

When a disease-carrying microbe enters our body, the body produces antibodies to fight the invader. The body also remembers how to fight the microbe if it enters again. So, if dead or weakened microbes are introduced in a healthy body, the body fights and kills them by producing suitable antibodies. The antibodies remain in the body and we are protected from the disease causing microbes. This is how a vaccine works. Several diseases, including cholera, tuberculosis, smallpox and hepatitis can be prevented by vaccination.

Increasing Soil Fertility

Some bacteria and blue green algae are able to fix nitrogen from the atmosphere to enrich soil with nitrogen and increase its fertility. These microbes are commonly called biological nitrogen fixers.

MICROORGANISMS AS FOES

Harmful Microorganisms

Microorganisms are harmful in many ways. Some of the microorganisms cause diseases in human beings, plants and animals. Such disease-causing microorganisms are called pathogens. Some microorganisms spoil food, clothing and leather.

Disease— causing Microorganisms in Humans

Pathogens enter our body through the air we breathe, the water we drink or the food we eat. They can also get transmitted by direct contact with an infected person or carried through an animal. Microbial diseases that can spread from an infected person to a healthy person through air, water, food or physical contact are called communicable diseases. Examples of such diseases include cholera, common cold, chicken pox and tuberculosis.

There are some insects and animals which act as carriers of disease causing microbes. Housefly is one such carrier. The flies sit on the garbage and animal excreta. Pathogens stick to their bodies. When these flies sit on uncovered food they may transfer the pathogens. Whoever eats the contaminated food is likely to get sick. Another example of a carrier is the female Anopheles mosquito, which carries the parasite of malaria. Female Aedes mosquito acts as carrier of dengue virus.

Some Common Human Diseases caused by Microorganisms

Disease— causing Microorganisms in Animals

Several microorganisms not only cause diseases in humans and plants, but also in other animals. For example, anthrax is a dangerous human and cattle disease caused by a bacterium. Foot and mouth disease of cattle is caused by a virus.

Disease— causing Microorganisms in Plants

Several microorganisms cause diseases in plants like wheat, rice, potato, sugarcane, orange, apple and others. The diseases reduce the yield of crops. They can be controlled by the use of certain chemicals which kill the microbes.

Food Poisoning

Food poisoning could be due to the consumption of food spoilt by some microorganisms. Microorganisms that grow on our food sometimes produce toxic substances. These make the food poisonous causing serious illness and even death. So, it is very important that we preserve food to prevent it from being spoilt.

Food Preservation

Microorganisms spoil our food. Spoiled food emits bad smell and has a bad taste and changed colour.

CONCLUSION 

 AT LAST IT CAN BE CONCLUDED THAT MICROORGANISMS ARE OUR FRIENDS AS WELL AS OUR FOES TOO.