2. Economic Significance of Microorganisms

3. Microorganisms Microorganisms are small living things that can only be seen under high power microscope. Microorganisms include: –Virus –Bacteria –Protozoa –Microscopic Fungi –Microscopic Algae

4. Use of Micro-organisms in environment 1.Fixation of atmospheric nitrogen 2.Decomposition of organic wastes and residues 3.Suppression of soil-borne pathogens 4.Recycling and increased availability of plant nutrients 5.Degradation of toxicants including pesticides 6.Production of antibiotics and other bioactive compounds 7.Production of simple organic molecules for plant uptake 8.Complexation of heavy metals to limit plant uptake 9.Solubilization of insoluble nutrient sources 10.Production of polysaccharides to improve soil aggregation

5. Beneficial Microorganisms AntibioticsAntibioticsAntibiotics Food ProductionFood ProductionFood ProductionFood Production Soil Fertility and Bacteria and FungiSoil Fertility and Bacteria and FungiSoil Fertility and Bacteria and FungiSoil Fertility and Bacteria and Fungi Combating PollutionCombating PollutionCombating PollutionCombating Pollution

6. Antibiotics Antibiotic is chemical substance produced by microorganisms that can kill or inhibit the growth of other microorganisms. Antibiotics kill or inhibit other organisms by interfering the metabolic process in the bacterium that is not found in the host.

7. Penicillin conidia conidiophores phialides

8. Food Production Fermentation: C 2 H 12 O 6  2C 2 H 5 OH + 2CO 2 + energy Dairy Products: cheese, yogurt and butter Wine and bread: yeast (Saccharomyces cerevisaea)

10. Soil Fertility and Bacteria and Fungi

11. Formation of Humus: –Organic compounds are decomposed by saprophytic bacteria. Nitrogen Fixation –Nitrogen  Ammonia Nitrifying bacteria –NH 4 +, NH 3 Nitrosomona NO 2 - nitrobacter NO 3 -

12. Combating Against Pollution Sewage Treatment. Oil spillage: Pseudomonas sp.can digest the oil into harmless forms.

13. Sewage Treatment (1) Primary treatment –In the sewage treatment plant the solid organic matter is moved from the sewage as sludge which may be treated further to form fertilizer.

14. Sewage Treatment (2) Secondary treatment: –The organic matter left in solution and suspension are decomposed rapidly by the added micro- organisms (e.g. Bacillus, Pseudomonas, Vorticella )

15. Sewage Treatment (3) Tertiary treatment: –Finally all the micro-organisms are killed by adding chlorine to the effluent of the treated sewage which can run into the rivers without causing any pollution problems.

16. Water Treatment of HK

17. Microorganism in other productions vaccines amino acid Enzymes (invertase) Vitamins (e.g. B2)

18. Harmful Organisms Causing Diseases. Food Spoilage. This orange is covered by fungus. Source from: Microbiology: Essentials and Application (2nd Ed.). A child infected by mumps. Source from : Microbiology: Essentials and Applications. (2nd Ed.)

19. Microorganisms and Diseases Pathogens are microorganisms that cause disease in animals and crops. Any organisms that carry pathogen from one living organism to another is called vector.

20. Virus Virus cause diseases by disturbing the homeostatic condition of the host cells.

21. Viral diseases Plant virus: Tobacco Mosaic Virus Human diseases caused by virus: -Small pox -Measles -Influenza -Hepatitis B -AIDS

25. AIDS Acquire Immune Deficiency Symptom. It is caused by Human Immunodeficiency Virus (HIV). Affects T-helper cells, making body defense system unable to combat against disease. Mainly spread through sexual intercourse and blood transfer.

26. HIV bud from the surface of an infected Helper T cell

28. Hepatitis B

30. Pathogenic Bacteria Pathogenic bacteria caused diseases by: –destroy the body tissues of the host directly –excrete toxins –release toxin from cell wall after death Diseases caused by bacteria: –Cholera, Typhoid fever –Pneumonia, Whooping cough, Tuberculosis –Gonorrhea, Syphilis –Food poisoning

31. The Structure of Bacteria

32. E.coli

33. Fungal Diseases -Fungal diseases are called mycoses which affect the skin, nails and hair follicles

34. Methods to control the spread of diseases 1.Prevention  Personal and Public hygiene  Immunization 2.Treatment  Chemotherapy  Surgery

35. Food Preservation Spoilage of food is caused by saprophytic bacteria. Basic principle of food preservation: –Killing the microorganisms in food; –Stopping or inhibiting their growth. Pickling of Food. Source from: Biology: A Modern approach. (2nd Ed.)

36. Food Preservation Techniques  Thermal Processing  Refrigeration  Drying  Food Additives  Canning  Smoking

37. Thermal Processing Heating Pasteurization

38. Refrigeration

39. Drying

40. Food Additive

41. Canning

42. Smoking