Module 1

Founders and Basic Concepts

1. Father of Microbiology – Louis Pasteur
2. Father of Agricultural Microbiology – Martinus Willem Beijerinck
3. Father of Soil Microbiology – Sergei Winogradsky
4. Father of Bacteriology – Robert Koch
5. Father of Virology – W. M. Stanley (isolated TMV in 1935)
6. Father of Modern Microbiology – Louis Pasteur
7. Father of Antibiotics – Alexander Fleming (discovered Penicillin, 1929)
8. Father of Microbial Ecology – Beijerinck
9. Mycology – Study of fungi
10. Phycology – Study of algae

Important Discoveries

1. Pasteurization was developed by Louis Pasteur.
2. Gram staining was discovered by Christian Gram (1884).
3. Penicillin was discovered by Alexander Fleming (1929).
4. DNA as genetic material proved by Avery, MacLeod & McCarty (1944).
5. Transformation in bacteria was discovered by Griffith (1928).
6. Nitrogen fixation in legumes was discovered by Hellriegel & Wilfarth (1888).
7. Rhizobium forms nodules on legume roots.
8. Frankia forms nodules in non-leguminous plants (e.g. Alnus).
9. Azospirillum is associated with cereals like maize and sorghum.
10. Azotobacter fixes nitrogen aerobically in soil.

Biofertilizers

1. Rhizobium – Symbiotic nitrogen fixer (in legumes).
2. Azospirillum – Associative symbiotic nitrogen fixer.
3. Azotobacter – Free-living nitrogen fixer.
4. Blue-Green Algae (BGA) – e.g., Anabaena, Nostoc, Tolypothrix.
5. Anabaena azollae – Found in Azolla (used in rice fields).
6. Frankia – Symbiotic nitrogen fixer in Alnus, Casuarina.
7. Phosphate solubilizing bacteria (PSB) – Pseudomonas, Bacillus megaterium.
8. Potassium solubilizing bacteria – Frateuria aurantia.
9. Zinc solubilizing bacteria – Bacillus subtilis.
10. Phosphate mobilizing fungi – Aspergillus niger, Penicillium.

Nitrogen Fixation

1. Nitrogenase enzyme helps in biological nitrogen fixation.
2. Cofactor of nitrogenase enzyme – Molybdenum (Mo).
3. Hydrogenase enzyme protects nitrogenase from oxygen.
4. Leghaemoglobin in root nodules regulates oxygen.
5. Nif genes control nitrogen fixation.
6. Heterocysts – Specialized nitrogen-fixing cells in cyanobacteria.
7. Non-symbiotic N fixers – Azotobacter, Clostridium.
8. Symbiotic N fixers – Rhizobium, Frankia.
9. Associative symbiotic N fixers – Azospirillum.
10. Anaerobic N fixer – Clostridium pasteurianum.

Fungi and Mycorrhiza

1. Mycorrhiza – Symbiotic association of fungi with plant roots.
2. Ectomycorrhiza – Fungi around roots (e.g., pine, oak).
3. Endomycorrhiza (VAM) – Fungi inside root cortex (e.g., Glomus).
4. VAM – Vesicular Arbuscular Mycorrhiza.
5. VAM fungi improve – Phosphorus uptake and drought resistance.
6. Trichoderma – Bio-control agent against fungal pathogens.
7. Gliocladium – Antagonistic fungus used in bio-control.
8. Aspergillus niger – Used in citric acid production.
9. Yeast (Saccharomyces cerevisiae) – Used in alcohol fermentation.
10. Penicillium chrysogenum – Source of penicillin.

Microbes in Soil and Decomposition

1. Ammonification – Conversion of organic N into ammonia.
2. Nitrification – Conversion of NH₄⁺ → NO₂⁻ → NO₃⁻.
3. Nitrifying bacteria – Nitrosomonas, Nitrobacter.
4. Denitrification – Conversion of nitrate to nitrogen gas (Pseudomonas denitrificans).
5. Sulphur oxidizing bacteria – Thiobacillus thiooxidans.
6. Iron bacteria – Ferrobacillus ferrooxidans.
7. Methanogens – Produce methane in anaerobic conditions (e.g., Methanobacterium).
8. Actinomycetes – Filamentous bacteria; produce antibiotics.
9. Streptomyces – Produces streptomycin, tetracycline, etc.
10. Cellulose decomposers – Cellulomonas, Trichoderma, Bacillus subtilis.