Study Notes on Micro-organisms and Their Applications

Applications of Micro-organisms

1.1 Micro-organisms

• Definition: Micro-organisms are organisms that can be unicellular or multicellular, generally not visible to the naked eye.
• Assignment 1.1: Prepare a list of the groups of micro-organisms and include names of micro-organisms corresponding to each category.
• Habitat: Live in various environments, including the human body.
• Characteristics:
  • Most micro-organisms are beneficial to humans and other organisms, but some can be harmful.
  • They are widespread and represent a large category of living organisms on Earth.
  • Micro-organisms have a simple structure and exhibit rapid growth and high reproduction rates.
  • Adaptability to different environmental conditions and nutritional modalities.
• Categories of Micro-organisms:
  • Bacteria
  • Fungi
  • Algae
  • Protozoa
  • Viruses (have characteristics of both living and non-living entities).

1.2 Environments and Substrates of Micro-organisms

• Ecosystems: Micro-organisms can be found in all ecosystems where other living organisms exist, including soil, water, and up to 6 km in the atmosphere.
• Environmental Conditions: Micro-organisms survive in extreme conditions, such as:
  • Hot springs
  • Salt marshes
  • Hydrocarbons like petrol and diesel.
• Specific Substrates for Growth:
  • Meat, fish, fruits, vegetables
  • Human skin, mouth, alimentary canal, urinary tract.

1.3 Effects of Micro-organisms

1.3.1 Beneficial Effects

1. Applications in Agriculture:
   • Gene Technology:
     • Development of drought-resistant, pest-resistant, and nutrient-rich crops.
     • Example: Erwinia uredovora gene used in Golden Rice for Vitamin A enrichment.
     • Bacillus thuringiensis gene introduced into Zea maize for pest toxin production.
   • Nitrogen Fixation:
     • Despite nitrogen constituting 78% of the atmosphere, plants cannot directly utilize it.
     • Rhizobium bacteria in legume nodules facilitate nitrogen absorption (Nitrogen fixation).
     • Bio-fertilizers: Commercially produced Rhizobium and Azotobacter increase soil nutrient levels.
   • Producing Compost:
     • Rapid decomposition of organic matter by microorganisms enriches soil.
   • Bio-Pesticides:
     • Micro-organisms like Alternaria combat pests such as Salvinia.

1.3.2 Applications in Medicine

• Antibiotics Production:
  • Chemicals produced by microbes that destroy other microorganisms.
  • Common antibiotics include:
  • Penicillin
  • Amoxicillin
  • Tetracycline
  • Erythromycin (for bacteria)
  • Griseofulvin (for fungi).
  • Discovery: Penicillin discovered by Alexander Fleming using Penicillium notatum.
• Vaccine Production:
  • Vaccines may involve weakened, killed, or toxin-derived agents from microbes.
  • Examples:
  • Weakened: Polio, Tuberculosis, Measles
  • Killed: Cholera, Influenza, Typhoid
  • Toxin-based: Tetanus, Diphtheria
  • Genetically engineered: Hepatitis B.
• Anti-Toxins: Biochemical substances from pathogens are used in vaccines after toxic components removal.

1.3.3 Applications in Industries

• Fields using industrial microbiology:

  • Dairy products (yoghurt, cheese)
  • Biogas production
  • Metal extraction
  • Plant fiber products
  • Alcohol production
  • Vinegar industry
  • Bakery products.

• Biogas Production:

  • Generated by anaerobic bacteria acting on organic materials like straw and cow dung, resulting in methanogenesis.

• Metal Extraction (Bio-Leaching):

  • Microbes like Acidithiobacillus can leach metals such as copper and uranium.

1.4 Adverse Effects of Micro-organisms

1.4.1 Diseases in Humans

• Pathogen Definition: Micro-organisms causing diseases are termed pathogens.
• Transmission Vectors: Diseases can spread through various means (air, water, food, vector).
• Common Diseases and Pathogens:

Table 1.2 - Diseases in Humans

1.4.2 Diseases in Plants

• Common Diseases:
  • Powdery Mildew Disease: A fungus causing white or gray powdery material on infected parts.
  • Late Blight: Affected potatoes show brown spots due to fungal attack.
  • Wilting: Caused by fungi or bacteria impacting the water-transporting xylem.

Summary

• Key Points:
  • Micro-organisms encompass various groups including bacteria, fungi, algae, protozoa, and viruses.
  • They thrive in numerous ecosystems and extreme environments.
  • Applications are diverse in agriculture, medicine, industry, and environmental conservation.
  • There are adverse effects including diseases, spoilage, and the potential for biological weapon use.

Exercises

1. Choose the correct answer from provided questions.
2. True/False statement verification.
3. Provide detail answers to application and health habit questions.