2. Microorganisms are very tiny one-celled organisms, viruses,
fungi, and bacteria, and are found everywhere in the world. 3.
MicrobiologyThe study of microorganisms is calledmicrobiology.The
microbes were seen for the first time in 1677 with help of a
simplemicroscope developed by Anton Van levenhoek 4. Anton Van
levenhoek Antonie Evan Leeuwenhoekis commonly known as "the Father
ofMicrobiology", and considered to bethe first microbiologist. He
is bestknown for his work on theimprovement of the microscope and
forhis contributions towards theestablishment of microbiology. 5.
Amoeba parameciumSpirogyraChlamydomonas Bread mouldvirus
penicillium aspergillum 6. Chlamydomonas is a genus of greenalgae
they are unicellular flagellates. Chlamydomonas is used as a
modelorganism for molecular biology,especially studies of flagellar
motilityand chloroplast dynamics, biogenesis,and genetics. 7.
Spirogyra is a genus offilamentous green algae ofthe order
Zygnematales, namedfor the helical or spiralarrangement of the
chloroplaststhat is diagnostic of the genus.They are found in fresh
waterareas. 8. The amoeba is a tiny, one- celled organism. You
needa microscope to see mostamoebas - 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 typesof amoebas. The name amoeba comes from the
Greek word amoibe, which means change. (Amoeba issometimes spelled
ameba.) 9. Paramecium is a groupof unicellular ciliate
protozons,which are commonly studied as arepresentative of the
ciliategroup, and range from about 50to 350 cm in length. 10. Bread
mold is a kind offungus that is commonly foundon bread surfaces. It
takesfood and nutrients from thebread and causes damage tothe
surface where it lives. Itcauses a bad taste to thebread also. But
the mold hasa place in the industry whereit serves as a decomposer
thatcan decompose decayed plantsand animals. 11. Penicillium isa
genus of ascomycetousfungi ofmajor importance in the
naturalenvironment as well as food anddrug production. Itproduces
penicillin, which is usedas an antibiotic. 12. Aspergillus is a
genus consisting ofseveral hundred mold species found invarious
climatesworldwide. Aspergillus was firstcatalogued in 1729 by the
Italianpriest and biologist Pier AntonioMicheli 13. A virus is a
small infectiousagent that can replicate onlyinside the living
cells oforganisms. Most viruses are toosmall to be seen directly
witha light microscope. Viruses infectall types of organisms,from
animals and plants to bacteria and archaea. 14. Name of theyear
contributionscientistRobert Hooke 1665 He observed cork cellLouis
Pasteur1885 He proved that fermentation is a
biochemicalprocessRobert Koch1872 He proved that the mycobacterium
is maincause of tuberculosisAlexander flemming 1929 He prepared
first antibiotic from Penicilliumnotatum 15. HABITTAT OF
MICROORGANISMSThey 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
existsfreely. 16. USES OF MICROORGANISMSMicroorganisms 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 productsLactobacillus bacteria
promotes formation milk productslike curd, cheese, etc.This
bacteria multiplies in milk to form curd. 18. Making of bakery
productsMaking 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 microorganismsMicroorganisms 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 etcYeast 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 fightthe invader. The body
also remembers how to fight the microbe if it enters again. So,
ifdead or weakened microbes are introduced in a healthy body, the
body fights and killsthem by producing suitable antibodies. The
antibodies remain in the body andwe are protected from the disease
causing microbes. This is how a vaccine works.Several diseases,
including cholera, tuberculosis, smallpox and hepatitis can
beprevented by diseases . Edward Jenner discovered the vaccine for
small pox in 1798. 22. Cleaning the environmentWe often see large
amounts of dead organic matter in the form of decaying plantsand
sometimes dead animals on the ground. You find that they disappear
aftersome time. This is because the microorganisms decompose dead
organic waste ofplants and animals converting them into simple
substances. These substances areagain used by other plants and
animals. Thus, microorganisms can be used todegrade the harmful and
smelly substances and thereby cleanup the environment. 23. Harmful
microorganismsMicroorganisms are harmful in many ways. Some of the
microorganismscause diseases in human beings, plants and animals.
Such disease-causing microorganisms are called pathogens. Some
microorganisms spoilfood, clothing and leather. Let us study more
about their harmfulactivities. 24. Increasing soil fertilitySome
bacteria and blue green algae are able to fix nitrogen from
theatmosphere to enrich soil with nitrogen and increase its
fertility. Thesemicrobes are commonly called biological nitrogen
fixers. 25. Disease causing microorganisms in humansThere are some
insects and animals which act as carriers of disease
causingmicrobes. Housefly is one such carrier. The flies sit on the
garbage andanimal excreta. Pathogens stick to their bodies. When
these flies sit onuncovered food they may transfer the pathogens.
Whoever eats thecontaminated 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
ofPreventive MeasuresMicroorganism TransmissionTuberculosis
bacteria AirKeep the patient in completeMeaslesVirus Air isolation.
Keep the personalChicken PoxVirus Air/contact belongings of the
patient awayPolioVirus Air/Water from those of the others.Cholera
Bacteriawater/food Maintain personal hygieneTyphoid Bacteria water
and good sanitary habits. Consume properly cooked food and boiled
drinking water. VaccinationHepatitisVirusWaterDrink boiled drinking
water. Vaccination.MalariaProtozoa 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 killthe microbes. 29. Food poisoningFood
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
preservationThe process of preserving food from spoiling is called
food preservation. Methods of food preservation1.chemical
method2.Preservation by common salt3.Preservation by
sugar4.Preservation by oil and vinegar5.Heat and cold
treatments6.Storage and packing 31. Chemical methodmany chemical
substances help inpreservation of food materialsby arresting the
growth ofmicroorganisms in them .Lemon preserved in commonsalt
sweet known as Agra kapetha,Murabba etc . are theexamples of
preservation bydehydration . Acetic acid,Benzoic acids are used
aspreservatives 32. Preservation by common saltCommon salt is used
for preserving meat and fishes for ages. Meat and fish arecovered
with common salt . Salting is also for storing alma.Preservation by
sugarJams, jellies and squashes are preserved by sugar. Sugar
reduces the moisturewhich inhibits the bacteria which spoils the
food. 33. Preservation by oil and vinegarUse 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 treatmentsYou must have observed
your mother boiling milk before it is stored or used.Boiling kills
many microorganisms . Similarly, we keep our food our food inthe
refrigerator. Low temperature inhibits the growth of
microorganisms.PasteurisationPasteurised milk can be consumed
without boiling as it is free from harmful microbes. ThemilkIs
heated about 70* for 15 to 30 seconds and then suddenly chilled and
stored. By doingso, it prevents the growth of microbes. This
process was discovered by Louis pasteur.it iscalled pasteurisation.
35. Nitrogen cycleOur atmosphere has 78% of nitrogen gas. Nitrogen
is one of the essential constituents ofall living organisms as part
of protiens,chlorophyll,nuclic acids and vitamins. Theatmospheric
nitrogen cannot be taken directly by plants and animals. certain
bacteriaand blue green algae present in the soil fix nitrogen from
the atmosphere and convert itinto these usable compounds, it can be
utilised by plants from soil by their roots.EG-Azotobacter 36.
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. 37. They may be unicellular or multicellular.
Microorganisms include bacteria, fungi,protozoa and some algae.
Viruses, thoughdifferent from the above mentioned livingorganisms,
are considered microbes. Viruses are quite different from
othermicroorganisms. They reproduce only insidethe host organism;
bacterium, plant or animalcell. 38. Some microorganisms are useful
forcommercial production of medicines andalcohol. Some
microorganisms decompose the organicwaste and dead plants and
animals into simplesubstances and clean up the environment.
Protozoan cause serious diseases likedysentery and malaria. 39.
Some of the microorganisms grow on our foodand cause food
poisoning. Some microorganisms reside in the rootnodules of
leguminous plants. They can fixnitrogen from air into soil and
increase thesoil fertility. Some bacteria and blue green algae
presentin the soil fix nitrogen from the atmosphereand convert into
nitrogenous compounds. 40. Certain bacteria convert compounds of
nitrogen present in the soil intonitrogen gas which is released to
the atmosphere.
