science

• Applications of micro-organisms


  • Used in agriculture
  • Used in medicine
  • Used in industries
  • Used for environmental conservation
• Gene technology


  Genetic engineering of micro-organisms
• Golden Rice


  • Genetically engineered rice enriched with vitamin A
• Nitrogen fixation


  Process where bacteria like Rhizobium and Azotobacter absorb atmospheric nitrogen and make it available to plants
• Producing compost


  1. Rapid decomposition of organic matter by micro-organisms

  2. Compost adds minerals to soil and makes favourable conditions for plant growth
• Bio-pesticides


  • The fungus Alternaria used to combat the aquatic weed, salvinia
• Antibiotics


  Chemicals produced by micro-organisms to destroy or sabotage other micro-organisms
• Antibiotics


  • Penicillin
  • Amoxicillin
  • Tetracycline
  • Erythromycin
  • Griseofulvin
• Vaccines


  Contain an agent that resembles a disease causing micro-organism, often made from weakened or killed forms of the microbe or from its toxins
• Anti-toxins


  Bio-chemical substances produced to neutralize the toxic components of toxins produced by pathogenic bacteria
• Anti-toxins


  • Tetanus vaccine
• Industries using micro-organisms


  • Producing dairy products
  • Producing biogas
  • Metal extraction
  • Products based on plant fibres
  • Producing alcohol
  • Producing vinegar
  • Bakery industry
• Bio-leaching


  Simple and effective technology used for metal extraction from low grade ores using micro-organisms
• Producing yoghurt


  1. Heat milk

  2. Remove cream

  3. Add sugar and gelatin

  4. Add culture yoghurt sample

  5. Incubate at 40-45°C for 6-7 hours

  6. Refrigerate
• Pectinase enzyme


  Helps separate plant fibres by digesting pectate which binds them together
• Advantages of using micro-organisms in industries

  • Rapid biological processes
  • Variety of strains capable of acting on different substances
  • Simple genes for genetic engineering
  • Low cost to obtain from environment
  • Low energy requirement
  • Minimal environmental damage
• Micro-organisms can cause diseases in humans, plants and animals
• Diseases caused by micro-organisms to humans

  • Cold (viruses)
  • Dengue (viruses)
  • AIDS (viruses)
  • Tuberculosis (bacteria)
  • Typhoid fever (bacteria)
  • Malaria (protozoa)
  • Amoebic dysentery (protozoa)
  • Leishmaniasis (protozoa)
  • Pityriasis (fungi)
  • Rashes (fungi)
• Bacillus thuringiensis is used as a biological control to destroy larval stages of dengue mosquitoes
• Diseases caused by micro-organisms to plants

  • Powdery mildew (fungus)
  • Late blight (fungus)
  • Wilting (fungi or bacteria)
• Food spoilage


  Micro-organisms multiply on food, converting components into unfavourable materials or adding toxic substances, making food unfit for consumption
• Food spoilage


  The change of physical and chemical nature of food makes the food unfit for consumption
• Micro-organisms are unicellular or multicellular organisms which cannot be seen clearly with the naked eye
• Main micro-organism categories


  • Bacteria
  • Fungi
  • Algae
  • Protozoa
• Viruses


  Have living and non-living characteristics but are also studied in microbiology
• Micro-organisms live within all the eco-systems with favourable environmental conditions and even under the extreme environmental conditions
• Fields where micro-organisms are used

  • Agriculture
  • Medicine
  • Industries
  • Environmental conservation
• Adverse effects of micro-organisms

  • Food spoilage
  • Diseases
  • Damage to economically important surfaces
  • Use as biological weapons
• Autotrophic micro-organisms


  • Algae
• Characteristics of viruses


  • No cellular organization
  • Multiply only in living cells
  • Do not show living characteristics such as respiration and growth
• Disease caused by bacteria

  • Tuberculosis
• Antibiotics are any chemical substance that is used to destroy or deactivate micro-organisms
• The vaccine given for tetanus contains weakened bacterial toxins
• Viruses are pathogens that display both living and non-living characteristics
• Most microbes in the environment are unfavourable to living beings
• Rhizobium bacteria found in the root nodules of legume plants fix atmospheric nitrogen
• The sclerotic layer in front of the iris becomes thin, transparent and forms the cornea
• The choroid layer supplies blood to the eye
• The light sensitive rod cells and cone cells are located in the retina layer
• The aqueous humour is a transparent watery liquid that fills the space between the lens and cornea