Module 6

1. Microbial inoculants are preparations containing beneficial microorganisms that improve soil fertility and crop productivity.
2. Azospirillum is an associative nitrogen fixer found in the rhizosphere of cereals like maize, wheat, and sorghum.
3. Phosphate Solubilizing Microorganisms (PSM) convert insoluble phosphate compounds into soluble forms available to plants.
4. Pseudomonas fluorescens acts as a bio-control agent against many soil-borne plant pathogens.
5. Trichoderma spp. are fungi used as biofungicides for seed and soil treatment.
6. Blue-green algae (BGA) fix atmospheric nitrogen in rice fields under submerged conditions.
7. Cyanobacteria are oxygenic photosynthetic prokaryotes containing chlorophyll a and phycobiliproteins.
8. Frankia forms actinorhizal symbiosis with non-leguminous plants like Alnus, Casuarina, and Myrica.
9. Rhizobium-legume symbiosis is an example of mutualism where both partners benefit.
10. Nod factors are lipochitooligosaccharides produced by Rhizobium that induce nodule formation.
11. Nitrogenase enzyme catalyzes the reduction of N₂ to NH₃ under anaerobic conditions.
12. Leghemoglobin in nodules regulates oxygen concentration for nitrogenase activity.
13. Ammonification is the microbial conversion of organic nitrogen into ammonia.
14. Nitrification is the oxidation of ammonia to nitrate via nitrite by Nitrosomonas and Nitrobacter.
15. Denitrification converts nitrate into nitrogen gas, leading to nitrogen loss from soil.
16. Sulphur oxidizing bacteria like Thiobacillus convert sulfides to sulfates.
17. Iron bacteria like Gallionella and Leptothrix oxidize ferrous iron to ferric form.
18. Manganese bacteria oxidize Mn²⁺ to Mn⁴⁺ and are important in soil weathering.
19. Silicate bacteria release soluble silica from insoluble silicate minerals, improving soil fertility.
20. Biofertilizers are substances containing living microorganisms that promote plant growth by increasing the supply or availability of nutrients.
21. The main types of biofertilizers include Rhizobium, Azospirillum, Azotobacter, Blue-Green Algae, and Phosphate Solubilizing Microorganisms (PSM).
22. Rhizobium inoculant is crop-specific and mainly used for leguminous crops.
23. Azotobacter is a free-living nitrogen-fixing bacterium found in the rhizosphere of non-leguminous plants.
24. Azospirillum forms loose associations with roots of cereals and grasses.
25. Blue-Green Algae (BGA) biofertilizer is widely used in rice fields.
26. Azolla, a water fern, has a symbiotic relationship with Anabaena azollae, a nitrogen-fixing cyanobacterium.
27. Phosphate solubilizing bacteria (PSB) include Bacillus megaterium and Pseudomonas striata.
28. Mycorrhizae are symbiotic associations between fungi and roots that enhance nutrient uptake.
29. Ectomycorrhiza forms an external sheath around roots (e.g., Pinus).
30. Endomycorrhiza (Vesicular Arbuscular Mycorrhiza – VAM) penetrates root cells to form arbuscules and vesicles.
31. VAM fungi belong mainly to the genera Glomus, Acaulospora, and Gigaspora.
32. Biofertilizers improve soil fertility, reduce chemical fertilizer use, and promote sustainable agriculture.
33. Composting is the microbial decomposition of organic matter under controlled conditions.
34. Aerobic composting produces humus-like material useful as manure.
35. Vermicomposting uses earthworms (like Eisenia foetida) to enhance decomposition.
36. Biogas production involves anaerobic digestion of organic waste by methanogenic bacteria.
37. The main gases in biogas are methane (60–70%) and carbon dioxide (30–40%).
38. Methanobacterium and Methanococcus are important methane-producing microorganisms.
39. Silage is preserved green fodder prepared through anaerobic fermentation by lactic acid bacteria.
40. Lactic acid bacteria (LAB) such as Lactobacillus plantarum are used in silage fermentation.
41. Microbial pesticides (biopesticides) use microorganisms to control insect pests and diseases.
42. Bacillus thuringiensis (Bt) produces Cry toxins that kill specific insect larvae.
43. Beauveria bassiana is an entomopathogenic fungus effective against many insect pests.
44. Trichoderma harzianum acts as a biofungicide and plant growth promoter.
45. Nuclear Polyhedrosis Virus (NPV) controls Helicoverpa armigera and other lepidopteran pests.
46. Biocontrol agents are eco-friendly alternatives to chemical pesticides.
47. Antagonism is the mechanism by which one microorganism suppresses another (e.g., Trichoderma vs Fusarium).
48. Antibiotics are secondary metabolites produced by microbes that inhibit other microorganisms.
49. Streptomyces species are known producers of antibiotics like Streptomycin and Tetracycline.
50. Bioleaching is the use of microorganisms to extract metals from ores.
51. Thiobacillus ferrooxidans is used in copper bioleaching.
52. Microbial biotechnology uses microbes in industrial production of enzymes, organic acids, and alcohols.
53. Yeast (Saccharomyces cerevisiae) is used in fermentation industries to produce alcohol and bread.
54. Lactic acid bacteria produce curd, yogurt, and cheese by fermenting milk.
55. Acetobacter aceti converts ethanol to acetic acid (vinegar).
56. Penicillium chrysogenum produces the antibiotic Penicillin.
57. Aspergillus niger is used for the commercial production of citric acid.
58. Clostridium acetobutylicum produces acetone and butanol.
59. Microbial enzymes like amylase, protease, and cellulase are used in food and textile industries.
60. Bioethanol is produced from sugarcane molasses and corn by yeast fermentation.
61. Bioremediation uses microorganisms to degrade pollutants and clean up the environment.
62. Oil-degrading bacteria like Pseudomonas putida are used for petroleum spill cleanup.
63. Phytoremediation involves plants and their associated microbes to detoxify contaminated soils.
64. Bioaugmentation refers to the addition of specific microbial strains to enhance biodegradation.
65. Biosensors are analytical devices combining biological components with a physicochemical detector.
66. Genetically Modified Microorganisms (GMMs) are engineered for enhanced metabolic activities.
67. Agrobacterium tumefaciens is used in genetic engineering to transfer genes into plants.
68. Ti plasmid of Agrobacterium acts as a natural vector for gene transfer.
69. Microbial genetics helps in understanding mutation, recombination, and resistance development in microbes.