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 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 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.
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 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 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 contributionscientistRobert Hooke 1665 He observed cork cellLouis Pasteur 1885 He proved that fermentation is a biochemical processRobert Koch 1872 He proved that the mycobacterium is main cause of tuberculosisAlexander 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 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 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 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 and we 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 microorganisms Microorganisms 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 of Preventive Measures Microorganism TransmissionTuberculosis bacteria Air Keep the patient in completeMeasles Virus Air isolation. Keep the personalChicken Pox Virus Air/contact belongings of the patient awayPolio Virus Air/Water from those of the others.Cholera Bacteria water/food Maintain personal hygieneTyphoid Bacteria water and good sanitary habits. Consume properly cooked food and boiled drinking water. VaccinationHepatitis 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 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 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 saltCommon 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 sugarJams, jellies and squashes are preserved by sugar. Sugar reduces the moisture which 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 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
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, 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.
38.  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.
39.  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.
40.  Certain bacteria convert compounds of nitrogen present in the soil intonitrogen gas which is released to the atmosphere.