Microorganisms used in biofertilizers

A presentation done on microorganism types and their action in bio fertilizers.

1. Microorganisms in Bio Fertilizer B V C M Benaragama

2. What are Bio Fertilizers? Fertilizers produced biologically, mainly using microorganisms.

3. Types of MOs used in manufacturing Bio fertilizers Rhizobium Bacteria Azotobacter Azospirillum Phosphate Solubilizing Bacteria (PSB) Blue Green Algae (BGA)

4. Rhizobium Bacteria Function Rhizobium have the ability to fix atmospheric nitrogen which is unavailable for plants. Rhizobium transform atmospheric nitrogen into nitrates. Example Rhizobium leguminosarum

5. Mechanism Legumes have a symbiotic relationship with rhizobia (root nodule bacteria) Rhizobia have the ability to fix atmospheric nitrogen into nitrates Then those nitrates are available to the host plant, the legume.

6. Applications Rhizobium Species Host Plants Bradyrhizobium japanicum Soyabean Rhizobium fredii Soyabean R. phaseoil Common Bean R. meliloti Alfalfa R. trifolii Peas

7. Azotobacter Bacteria Function Azotobacter is a free-living nitrogen-fixing bacterium. Which is used as a biofertilizer in the cultivation of most crops. Example Azotobacter vinelandii

8. Mechanism Biological nitrogen fixation under free-living conditions . Production of phytohormones like indole 3-acetic acid gibberrillin-like substances and cytokinins. Solubilization of insoluble phosphate.

9. Applications Azotobacter fertilizer can be used for wide range of plants some of them are given below Tomato Rice Potato Cotton Wheat Lemon Mango Kinnaw

10. Azospirillum Function Azospirillum is one of the most widely used free living nitrogen fixing microgrnisms from the family of Rhodospirilliaceae They can be found both in in legume and non legume crops Example Azotobacter vinelandii

11. Mechanism Azospirillum on plants Produce of phytohormones, Fix of atmospheric nitrogen, Reduction of nitrate, Enhance of mineral uptake by plant

12. Applications Bacterial species Used for A. brasilense , A. lipoferum , A. halopraeferens A. oryzae Used for biofertilizer,mainly for cereals Azospirillum brasilense Fix nitrogen in the presence of low oxygen level Azospirillum oryzae Associated with the roots of oryza sativa

13. Phosphate Solubilizing Bacteria Phosphorus is an essential macronutrient for plant Phosphate fertilizer is easily precipitated into soluble form Phosphate solublizing is activity greater for fungi than bacteria This bacteria are beneficial bacterial capable of solublizing inorganic phosphorus from insoluble compounds Scientific name - Bacillus megaterium

14. Mechanism Phosphate solubilizing microorganisms convert insoluble phosphate into soluble form Through the processes of acidification, by the production of organic acids, production of acid and alkaline phosphate These organic acid can either dissolve phosphate as a result of anion exchange

15. Applications Bacterial species Used for Bacillus megaterium Used to enhance Cd bioavailability and plant biomass B. megaterium Increased the extent of Cd accumulation The change of Cd indicated that inoculation

16. Blue Green Algae Blue-green algae are actually a type of bacteria that is known as Cyanobacteria. Function Use the sun's energy to manufacture their own food through photosynthesis. Fix atmospheric nitrogen level Examples Nostocales, Spirulina

17. Mechanism They have chlorophyll and phycobiliprotein and can fix carbon by oxygen-evolution photosynthesis like plants They have Heterocysts cells Heterocysts cells provide the anaerobic (oxygen-free) environment necessary for the operation of the nitrogen-fixing enzymes.

18. Applications Bacterial species Used for Spirulina As a natural food coloring in gum and candy Nostocales To fix nitrogen level, For avoid water pollution Anabaena, Nostoc and Oscillatoria produce a great variety of secondary metabolites.

19. Advantages Improves soil organic matter Improves soil structure and tilth Improves soil water holding capacity Reduces soil crusting problems Reduces erosion from wind and water Disadvantages Not essentially rich in all nutrients Shorter shelf life Does not adapt as per the situation

20. Questions?