Economic Significance of Microorganisms

Microorganisms

• Microorganisms are small living things that can only be seen under high power microscope.

• Microorganisms include:– Virus

– Bacteria

– Protozoa

– Microscopic Fungi

– Microscopic Algae

Use of Micro-organisms in environment

1.1. Fixation of atmospheric nitrogen Fixation of atmospheric nitrogen

2.2. Decomposition of organic wastes and residues Decomposition of organic wastes and residues

3.3. Suppression of soil-borne pathogens Suppression of soil-borne pathogens

4.4. Recycling and increased availability of plant nutrients Recycling and increased availability of plant nutrients

5.5. Degradation of toxicants including pesticides Degradation of toxicants including pesticides

6.6. Production of antibiotics and other bioactive compounds Production of antibiotics and other bioactive compounds

7.7. Production of simple organic molecules for plant uptake Production of simple organic molecules for plant uptake

8.8. Complexation of heavy metals to limit plant uptake Complexation of heavy metals to limit plant uptake

9.9. Solubilization of insoluble nutrient sources Solubilization of insoluble nutrient sources

10.10. Production of polysaccharides to improve soil aggregatioProduction of polysaccharides to improve soil aggregation n

Beneficial Microorganisms

• Antibiotics

• Food ProductionFood Production

• Soil Fertility and Bacteria and Soil Fertility and Bacteria and FungiFungi

• Combating PollutionCombating Pollution

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.

Penicillinconidia

conidiophoresphialides

Food Production

• Fermentation:

C2H12O6 2C2H5OH + 2CO2 + energy

• Dairy Products: cheese, yogurt and butter

• Wine and bread: yeast (Saccharomyces cerevisaea)

Soil Fertility and Bacteria and Fungi

• Formation of Humus:– Organic compounds are decomposed by saprop

hytic bacteria.

• Nitrogen Fixation– Nitrogen Ammonia

• Nitrifying bacteria– NH4

+, NH3 Nitrosomona NO2- nitrobacter NO3

-

Combating Against Pollution

• Sewage Treatment.

• Oil spillage: Pseudomonas sp.can digest the oil into harmless forms.

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.

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 )

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.

Water Treatment of HK

Microorganism in other productions

vaccinesamino acidEnzymes (invertase)Vitamins (e.g. B2)

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.)

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.

Virus

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

Viral diseases

• Plant virus: Tobacco Mosaic Virus

• Human diseases caused by virus:

-Small pox

-Measles

-Influenza

-Hepatitis B

-AIDS

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.

HIV bud from the surface of an infected Helper T cell

Hepatitis B

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

The Structure of Bacteria

E.coli

Fungal Diseases

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

Methods to control the spread of diseases

1. Prevention Personal and Public hygiene Immunization

2. Treatment Chemotherapy Surgery

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.)

Food Preservation Techniques

Thermal Processing

Refrigeration

Drying

Food Additives

Canning

Smoking

Thermal Processing

Heating Pasteurization

Refrigeration

Drying

Food Additive

Canning

Smoking