Microorganisms are tiny organisms that are too small to be seen with the naked eye. They can live in various environments ranging from ice cold climates to hot springs. Microorganisms include bacteria, fungi, protozoa, and some algae. Viruses are also considered microbes though they can only reproduce inside host cells. Some microorganisms are useful for producing medicines and alcohol, while others decompose organic waste and help clean the environment. However, some microorganisms can also cause diseases in humans, animals, and plants.

1. BY-
Sudhanshu Kathuria

2. Microorganisms are very
tiny one-celled organisms,
viruses, fungi, and
bacteria, and are found
everywhere in the world.

3. Microbiology
The study of microorganisms is called
microbiology.
The microbes were seen for the first time in 1677 with help of a simple
microscope developed by Anton Van levenhoek

4. Anton Van levenhoek
 Antonie Evan Leeuwenhoek
is commonly known as "the Father of
Microbiology", and considered to be
the first microbiologist. He is best
known for his work on the
improvement of the microscope and for
his contributions towards the
establishment of microbiology.

5. Amoeba paramecium
Spirogyra
Chlamydomonas
Bread mould
virus
penicillium
aspergillum

6.  Chlamydomonas is a genus of green
algae they are unicellular flagellates.
 Chlamydomonas is used as a model
organism for molecular biology,
especially studies of flagellar motility
and chloroplast dynamics, biogenesis,
and genetics.

7.  Spirogyra is a genus of
filamentous green algae of
the order Zygnematales, named
for the helical or spiral
arrangement of the chloroplasts
that is diagnostic of the genus.
They are found in fresh water
areas.

8.  The amoeba is a tiny, one-
celled organism. You need
a microscope to see most
amoebas - the largest
are only about 1 mm
across. Amoebas live in
fresh water (like puddles
and ponds), in salt water,
in wet soil, and in animals
(including people). There
are many different types
of amoebas. The name
amoeba comes from the
Greek word amoibe, which
means change. (Amoeba is
sometimes spelled
ameba.)

9.  Paramecium is a group
of unicellular ciliate protozons,
which are commonly studied as a
representative of the ciliate
group, and range from about 50
to 350 cm in length.

10. Bread mold is a kind of
fungus that is commonly found
on bread surfaces. It takes
food and nutrients from the
bread and causes damage to
the surface where it lives. It
causes a bad taste to the
bread also. But the mold has
a place in the industry where
it serves as a decomposer that
can decompose decayed plants
and animals.

11.  Penicillium is
a genus of ascomycetousfungi of
major importance in the natural
environment as well as food and
drug production. It
produces penicillin, which is used
as an antibiotic.

12.  Aspergillus is a genus consisting of
several hundred mold species found in
various climates
worldwide. Aspergillus was first
catalogued in 1729 by the Italian
priest and biologist Pier Antonio
Micheli

13.  A virus is a small infectious
agent that can replicate only
inside the living cells of
organisms. Most viruses are too
small to be seen directly with
a light microscope. Viruses infect
all types of organisms,
from animals and plants to bacte
ria and archaea.

14. Name of the year contribution
scientist
Robert Hooke 1665 He observed cork cell
Louis Pasteur 1885 He proved that fermentation is a biochemical
process
Robert Koch 1872 He proved that the mycobacterium is main
cause of tuberculosis
Alexander flemming 1929 He prepared first antibiotic from Penicillium
notatum

15. HABITTAT OF MICROORGANISMS
They can survive under all types of environment.
 Ranging from ice cold climate to hot springs.
Deserts to marshy lands.
They are found in the bodies of animals including humans.
 Some microorganisms grow on other organisms while others exists
freely.

16. USES OF MICROORGANISMS
Microorganisms are used :-
 For preparation of milk products.
 For making bakery products.
 Commercial use of microorganisms.
 Medicinal use of microorganisms.
 Used as vaccine.
 For increasing soil fertility.
 For cleaning up the environment.

17. Preparation of milk products
Lactobacillus bacteria promotes formation milk products
like curd, cheese, etc.
This bacteria multiplies in milk to form curd.

18. Making of bakery products
Making of bakery products like bread, cakes etc.
Yeast reproduces rapidly and produces carbon
dioxide during respiration.
Bubbles of the gas fill the dough and increase its
volume.

19. Commercial use of microorganisms
Microorganisms are used commercially for the production of wine,
alcohol and acetic acid.
Yeast is used for commercial production of alcohol and wine.
Yeast is grown on natural sugars present in grains like barley,
wheat etc
Yeast converts the sugar into alcohol by the process of
fermentation.

20. Medicinal use of microorganisms
 Microorganisms are used as medicines like antibiotics.
 Antibiotics kill or stops the growth of disease causing microorganisms.
 Tetracycline, Streptomycin and erythromycin are the examples of
antibiotics.

21. 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 diseases . Edward Jenner discovered the vaccine for small pox in 1798.

22. Cleaning the environment
We often see large amounts of dead organic matter in the form of decaying plants
and sometimes dead animals on the ground. You find that they disappear after
some time. This is because the microorganisms decompose dead organic waste of
plants and animals converting them into simple substances. These substances are
again used by other plants and animals. Thus, microorganisms can be used to
degrade the harmful and smelly substances and thereby cleanup the environment.

23. 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. Let us study more about their harmful
activities.

24. 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.

25. Disease causing microorganisms in humans
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.
Female anopheles mosquito Female aedes mosquito

26. 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.
Robert Koch was the person who discovered bacterium
which causes anthrax disease.

27. Human Disease Causative Mode of Preventive Measures
Microorganism Transmission
Tuberculosis bacteria Air Keep the patient in
complete
Measles Virus Air isolation. Keep the
personal
Chicken Pox Virus Air/contact belongings of the patient
away
Polio Virus Air/Water from those of the others.
Cholera Bacteria water/food Maintain personal
hygiene
Typhoid Bacteria water and good sanitary
habits.
Consume properly
cooked food
and boiled drinking
water. Vaccination
Hepatitis Virus Water Drink boiled drinking
water.
Vaccination.
Malaria Protozoa Mosquito Use mosquito nets and
repellents.

28. 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.
plant diseases. They can be controlled by the use of certain chemicals which kill
the microbes.

29. 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.

30. Food preservation
The process of preserving food from spoiling is called food preservation.
Methods of food preservation
1.chemical method
2.Preservation by common salt
3.Preservation by sugar
4.Preservation by oil and vinegar
5.Heat and cold treatments
6.Storage and packing

31. Chemical method
many chemical substances help in
preservation of food materials
by arresting the growth of
microorganisms in them .
Lemon preserved in common
salt sweet known as Agra ka
petha,Murabba etc . are the
examples of preservation by
dehydration . Acetic acid,
Benzoic acids are used as
preservatives

32. Preservation by common salt
Common salt is used for preserving meat and fishes for ages. Meat and fish are
covered with common salt . Salting is also for storing alma.
Preservation by sugar
Jams, jellies and squashes are preserved by sugar. Sugar reduces the moisture
which inhibits the bacteria which spoils the food.

33. Preservation by oil and vinegar
Use of oil and vinegar prevents spoilage of pickles because
bacteria cannot live in such an environ
ment.vegitables,fruits,fish and meat are often preserved by
this method.

34. Heat and cold treatments
You must have observed your mother boiling milk before it is stored or used.
Boiling kills many microorganisms . Similarly, we keep our food our food in
the refrigerator. Low temperature inhibits the growth of microorganisms.
Pasteurisation
Pasteurised milk can be consumed without boiling as it is free from harmful microbes. The
milk
Is heated about 70* for 15 to 30 seconds and then suddenly chilled and stored. By doing
so, it prevents the growth of microbes. This process was discovered by Louis pasteur.it is
called pasteurisation.

35. Nitrogen cycle
Our atmosphere has 78% of nitrogen gas. Nitrogen is one of the essential constituents of
all living organisms as part of protiens,chlorophyll,nuclic acids and vitamins. The
atmospheric nitrogen cannot be taken directly by plants and animals. certain bacteria
and blue green algae present in the soil fix nitrogen from the atmosphere and convert it
into these usable compounds, it can be utilised by plants from soil by their roots.
EG-Azotobacter

37. Microorganisms are too small and are not
visible to the unaided eye.
They can live in all kinds of environment,
ranging from ice cold climate to hot springs
and deserts to marshy lands.
Microorganisms are found in air, water and
in the bodies of plants and animals.

38.  They may be unicellular or multicellular.
 Microorganisms include bacteria, fungi,
protozoa and some algae. Viruses, though
different from the above mentioned living
organisms, are considered microbes.
 Viruses are quite different from other
microorganisms. They reproduce only inside
the host organism; bacterium, plant or animal
cell.

39.  Some microorganisms are useful for
commercial production of medicines and
alcohol.
 Some microorganisms decompose the organic
waste and dead plants and animals into simple
substances and clean up the environment.
 Protozoan cause serious diseases like
dysentery and malaria.

40.  Some of the microorganisms grow on our food
and cause food poisoning.
 Some microorganisms reside in the root
nodules of leguminous plants. They can fix
nitrogen from air into soil and increase the
soil fertility.
 Some bacteria and blue green algae present
in the soil fix nitrogen from the atmosphere
and convert into nitrogenous compounds.

41.  Certain bacteria convert compounds of nitrogen present in the soil into
nitrogen gas which is released to the atmosphere.