microorganism friends and foe for grade 8 science. fungi, bacteria, virus, protozoa, algae. How to preserve food from microorganism. canning, pasteurization, pickling, preservatives etc. preservatives. a presentation cbse and English medium.
3. Microorganism Unicellular/
Multicellular
Shape/Size Habitat Eating Habit
Bacteria
prokaryotic
Unicellular Shape-
rod-shaped
spherical-shaped and
spiral-shaped
Everywhere Autotrophic or
Heterotrophic
Fungi
Eukaryotic
Unicellular or
multicellular
Dead remains or In
living host
Heterotrophic
(saprophytes or
parasites).
Algae (Plants)
Eukaryotic
Unicellular or
multicellular
Water Autotrophic
Protozoa (Animals)
Eukaryotic
Unicellular or
multicellular
Water Heterotrophic
Virus ()
4. 1. Preparation of food
2. Sources of food
3. Industry- to produce alcohol, wine and vinegar
(acetic acid)
4. Agriculture
5. Antibiotics
6. Vaccines
7. Environment
8. Sewage treatment
5. USEFUL MICROORGANISMS
• Curd Lactobacillus Cheese Lactobacillus
or Streptococcus and rennet
• Bread, Idlee, Dhosa, Dhokla etc.
yeast
Preparation of Food
6. Rich Sources of Food
Rich sources of Protein and Vitamins.
Mushrooms (fungi) and
Yeast
Seaweeds are an important source of food in
China and
As food:
Many algae like Chlorella and seaweeds are
used as food.
7. • Vinegar (acetic acid)
• Acetobacter (from alcohol to
vinegar)
• Alcohol
• Yeast (in the absence of Oxygen
• Aspergillus
Commercial Use
13. Entry and
Prevention of
microorganism
Mouth
Water, Food
etc.
Hygienic and
fresh food
Nose
Air, Dust,
smoke etc.
Clean
Environment
Broken Skin
Carrier: Flies.
Dust, etc.
Cleaning and
uses of
antiseptic
14.
15. • Communicable:
• Diseases which can spread from one
person to another Example Cholera,
common cold, tuberculosis, malaria, chickenpox,
anthrax, measles, influenza.
• Non communicable Disease:
• Disease that is not transmitted through
contact with an infected or afflicted
person. Example Cancer
23. Advantage of Food Preservation
• Reduces food wastage due to spoilage
• Increases the shelf life (storage period) of food items
• Ensures food availability during off season and in distant places
• Maintains the nutritional value and flavour of food
24. Methods of Food Preservation
• Drying (dehydration):
• Boiling:
25. Methods of Food Preservation
• Refrigeration and freezing:
• Pasteurization:
26. Methods of Food Preservation (mitticool)
• Refrigeration and freezing:
http://www.mitticool.in/index.php
27. Methods of Food Preservation
• Canning (proper storage and
packing):
• Salting and adding sugars:
• Use of chemicals:
Editor's Notes
Nitrogen fixation is a process in which nitrogen (N2) in the atmosphere is converted into ammonium (NH4+) or nitrogen dioxide (NO2),
Two kinds of nitrogen-fixing bacteria are recognized: free-living (non-symbiotic)
cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium;
and mutualistic (symbiotic) bacteria such as Rhizobium, associated with leguminous plants (e.g., various members of the pea family), and certain Azospirillum species, associated with cereal grasses.
The inorganic compounds released during decomposition include gases like carbon dioxide, water vapour and minerals like nitrates, sulphates, phosphates and potassium ions. These are used by green plants during photosynthesis and other processes.
During the treatment of sewage, methane gas is produced by anaerobic bacteria. This is called biogas,
Cholera is an infection of the small intestine by some strains of the bacterium Vibrio cholerae.
The classic symptom is large amounts of watery diarrhea that lasts a few days.[3] Vomiting and muscle cramps may also occur.
Tuberculosis may infect any part of the body, but most commonly occurs in the lungs (known as pulmonary tuberculosis) (by-Mycobacterium tuberculosis)
General signs and symptoms include fever, chills, night sweats, loss of appetite, weight loss, and fatigue.[11] Significant nail clubbing may also occur.
Typhoid fever, also known simply as typhoid, is a symptomatic bacterial infection due to Salmonella typhi.
Symptoms : Often there is a gradual onset of a high fever over several days.[2] Weakness, abdominal pain, constipation, and headaches also commonly occur.
Measles,
Initial signs and symptoms typically include fever, often greater than 40 °C (104.0 °F), cough, runny nose, and red eyes.[1][3]
Two or three days after the start of symptoms, small white spots may form inside the mouth, known as Koplik's spots. A red, flat rash which usually starts on the face and then spreads to the rest of the body
Chickenpox, Symptoms - skin rash that forms small, itchy blisters, which eventually scab over.[2] It usually starts on the face, chest, and back and then spreads to the rest of the body
Poliomyelitis,. Approximately 90% to 95% of infections cause no symptoms.[1] Another 5 to 10% of people have minor symptoms such as: fever, headache, vomiting, diarrhea, neck stiffness and pains in the arms and legs.[1][2] These people are usually back to normal within one or two weeks.
Hepatitis B - affects the liver. Symptoms: Some develop a rapid onset of sickness with vomiting, yellowish skin, feeling tired, dark urine and abdominal pain Also Liver chronically inflamed and fibrotic , shrinking slightly
symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases it can cause yellow skin, seizures, comaor death The disease is transmitted most commonly by an infected female Anopheles mosquito.
Pasteurization (American English) or pasteurisation (British English) is a process invented by French scientist Louis Pasteur during the nineteenth century. In 1864,
To expose (a food, as milk, cheese, yogurt, beer, or wine) to an elevated temperature for a period of time sufficient to destroy certain microorganisms, as those that can produce disease or cause spoilage or undesirable fermentation of food, without radically altering taste or quality.
Canning is a method of preserving food in which the food contents are processed and sealed in an airtight container
Canning: In 1809, Nicolas Appert, a French confectioner and brewer, observed that food cooked inside a jar did not spoil unless the seals leaked, and developed a method of sealing food in glass jars.[2] Appert was awarded the prize in 1810 by Count Montelivert, a French minister of the interior