Microbes used as fertilizer is known as bio fertilizer.

1. SHRI SHANKARACHARYA
MAHAVIDYALA junwani ,BHILAI
“BIO-FERTILIZER”
DR. RACHANA CHOUDHARY
H.O.D (MICROBIOLOGY)

2. SYNOPSIS
• INTRODUCTION
• WHY MICROBES USED AS BIOFERTILIZER?
• HOW BIOFERTILIZERS WORK?
• TYPES OF BIOFERTILIZER
• Bacterial Biofertilizer
• Cyanobacterial Biofertilizer
• Mycorrizal Or VAM Biofertilizers
• Phosphorus Solubilizing Biofertilizers
• Siderophores Biofertilizers
A List Of Important Microorganisms
Bio-fertilizer Production and Commercially available bio-fertilizers
• ADVANTAGES OF BIOFERTILIZERS
• DISADVANTAGE OF BIOFERTILIZERS
• CONCLUSIONS AND FUTURE PROSPECTS
• REFERENCES

3. INTRODUCTION
• Over the years, chemical fertilizers have helped
farmers increase crop production to meet the
increasing demand.
• However, the overuse of these fertilizers is
harmful because they cause air and water
pollution; and also deplete minerals from the soil.
• Therefore, there is a need to now switch
to organic farming which involves the use of
‘Biofertilizers’.

4. • ‘Bio’ means ‘life’. Therefore, by definition biofertilizers
are living organisms that enrich the nutrient quality of
the soil. It refers to the use of microbes instead of
chemicals to enhance the nutrition of the soil. As a
result, it is also less harmful and does not cause
pollution.
The biological routes of improving soil fertility for
optimum crop production are operated by micro-
organisms & hence they known as biofertilizers also
called microbial inoculants.
• OR
In other words, “biofertilizers are the organism which
increases the nutrient availability to crop plants either
directly or through soil enrichment.

5. Why Microbes used as Biofertilizer?
• Microbes are effective in inducing plant growth
as they secrets plant growth promoters (auxins,
abscisic acid, gibberellic acid, cytokinis,
ethylene) and enhance seed germination and
root growth.
• They also play a considerable role in
decomposition of organic materials and
enrichment of compost .

6. How biofertilizers work?
☛ Biofertilizers fix atmospheric nitrogen in the soil and
root nodules of legume crops and make it available to the
plant.
☛ They solubilize the insoluble forms of phosphates like
tri-calcium, iron, and aluminium phosphates into
available forms
☛ They scavenge phosphate from soil layers.
☛ They decompose organic matter and help in
mineralization in soil.
☛ When applied to seed or soil, biofertilizers increase
the availability of nutrients and improve the yields by 10
to 25% without adversely affecting the soil and
environment.

7. TYPES OF BIOFERTILIZERS
Biofertilizer may be of following types:
• Bacterial biofertilizers.
• Cyanobacterial biofertilizers.
• Mycorrhizal or VAM biofertilizers.
• Phosphorus solubilizing biofertilizers.
• Siderophores biofertilizers.

8. A. BACTERIAL BIOFERTILIZER
A. Bacterial biofertilizers :
There are two types of bacteria which are used as
biofertilizers:
(a) Symbiotic bacteria: These bacteria are found
inside the nodulated roots of leguminous plants.
Example:- Rhizobium.
(b) Non- symbiotic bacteria:
Example:- Azotobacter , Azospirillum.

9. (a)Symbiotic bacteria: Rhizobium
It belongs to rhizobiaceae family, the rhizobium bacteria present in
the nodules of these crops are not always efficient. Therefore, the
competitive, efficient bacteria are isolated, screened, selected and
produced as carrier based inoculants
Morphology:
1) Unicellular, cell size less than 2µ wide. Short to medium rod,
Pleomorphic
2) Motile with Peritrichous flagella
3) Gram negative
4) Accumulate poly β-hydroxyl butyrate granules.

10. Physiology:
1) Nature : chemo heterotrophic, symbiotic with legume
2) C source: supplied by legume through photosynthesis,
mono & disaccharide.
3) N source: fixed from atmosphere.
4) Respiration: aerobic.
5) Growth: fast ( rhizobium), slow (Brady rhizobium)
6) Doubling time: fast grower- 2-4 hours slow grower 6-12
hours.
7) Growth media : YEMA
Recommended for :
Pulses: chickpea, pea, lentil, black gram,
green gram, cowpea, pigeon pea.
Oil seeds: soybean, groundnut.

11. Quantity of biological N fixed by Liqiud Rhizobium in
different crops
Host Group
Rhizobium
Species
Crops N fix kg/ha
Pea group Rhizobium
leguminosarum
Green pea,
Lentil
62- 132
Soybean group
R.japonicum Soybean 57- 105
Lupini Group R. lupine
orinthopus
Lupinus 70- 90
Alfafa grp.Group R.mellilotiMedi
cago Trigonella
Melilotus 100- 150
Beans group
R. phaseoli Phaseoli 80- 110
Clover group
R. trifoli Trifolium 130

12. Non symbiotic: Azotobacter Azospirillum.
Azotobacter
It belongs to azotobacteriaceae .It produces growth promoting
substances which improve seed germination and growth of
extended root system. It produces polysaccharides which improve
soil aggregation. Azotobacter suppresses the growth of
saprophytic and pathogenic micro-organism near the root system
of crop plants
Morphology:
1) Cell size: Large ovoid cells, size ranging
from 2.0-7.0×1.0-2.5µ.
2) Cell character: polymorphic
3) Accumulate poly β-hydroxyl butyrate
granules.
4) Gram reaction: negative

13. Physiology:
1) Nature: chemo heterotrophic, free living
2) C source: a variety of carbon source ( mono, di and certain
polysaccharide) organic acids.
3) N sources: Nitrogen through fixation, amino acid, NH4, NO3
4) Respiration: aerobic
5) Growth media: Ashby Jensen’s medium
6) Doubling time: 3 hours
Recommended for:
Rice, wheat, millets, other cereals, cotton, vegetable, sunflower,
mustard, flowers.

14. Azospirillium
It belongs to family spirillaceae.
The bacteria have been found to
live within the root of sorghum,
bajra and rage plants. They are chemoheterotrophic and association
in nature secrete growth regulatory substance
The use of azospirillium inoculants help in increasing yield of
millets. It significantly increase the growth, chlorophyll content and
mycorrhyzal infection in root.
Morphology:
1) Cell size: curved rod, 1mm in diameter, size and shape vary.
2) Accumulate: poly β-hydroxyl butyric acid.
3) Gram reaction: negative
4) Development of white pellicles 2-4mm below the surface of
NFB medium.

15. Physiology:
1) Nature: chemoheterotrophic, associative.
2) C source: organic acid, L-arabinose, D-gluconate, D-fructose, D-
glucose, sucrose, pectin.
3) N sources: nitrogen through fixation, amino acids, NH4, NO3
4) Respiration: aerobic, micro aerobic.
5) Growth media: N free bromothymol blue (NBF)
6) Doubling time: 1hr in ammonia containing medium, 5.5 to 7hr.
on malate containing semi-solid medium
Recommended for:
Rice, millets maize, wheat, sorghum, sugarcane and co-
inoculants for legumes.
.

16. Cyanobacteria or blue green algae include unicellular
and colonial species. Colonies may form filaments, sheets or even
hollow balls.
vegetative cells, photosynthetic cells that are formed under
favorable growing conditions; akinetes, ; and thick-
walled heterocysts, which contain the enzyme nitrogenase,
for nitrogen fixation.

17. C. Mycorrhizal or VAM biofertilizers.
• Mycorrhizae, mycorrhiza or mycorrhizas) is a
symbiotic association between a fungus and a plant.
The term mycorrhiza refers to the role of the fungus
in the plant's rhizosphere, its root system .
• Symbiotic (mutualistic) relationships, in which the
fungus obtains at least some of its sugars from the
plant, while the plant benefits from the efficient uptake
of mineral nutrients (or water) by the fungal hyphae.
However, there can be circumstances in which the
fungus is mildly detrimental, and others in which the
plant feeds from the fungus.

18. Types of Mycorrhizas
• Mycorrhizas are commonly divided into
• Ectomycorrhizas
• Endomycorrhizas.
• The two types are differentiated by the fact that the hyphae
of ectomycorrhizal fungi do not penetrate
individual cells within the root,
• while the hyphae of endomycorrhizal fungi penetrate the
cell wall and invaginate the cell membrane.[Endomycorrhiza
includes arbuscular, ericoid, and orchid mycorrhiza,
• while arbutoid mycorrhizas can be classified
as ectoendomycorrhizas.
• Monotropoid mycorrhizas form a special category.

19. Phosphate solubilizing bio fertilizer
• Phosphorus is one of the most important plant nutrients
and may be critical nutrient for the optimum growth of
plants. Most of our soils are in available forms of
phosphorus required phosphate application.
• In the rhizosphere of crops will render insoluble soil
phosphate available to plants due to production and
secretion of organic acid by them. The use of this bio
fertilizer will also increase the availability of phosphate
from rock phosphate applied directly even to neutral to
alkaline soil or when used for preparation of phosphor-
compost. Phosphate solubilizing micro-organism include
efficient strain of bacteria, fungi, yeast and actinomycetes
in that order

20. E. Siderophores biofertilizers.
• Siderophores (Greek: "iron carrier") are small, high-
affinity iron-chelating compounds that are secreted
by microorganisms such as bacteria and fungi and
serve primarily to transport iron across cell
membranes although a widening range of siderophore
functions is now being appreciated Siderophores are
among the strongest soluble Fe3+ binding agents
known.

21. ROLE OFSiderophores
• High Affinity System Of Fe3+ utilization & Storage.
• Sometimes requirement for virulence
• Helps in growth, Colonization and asexual sporulation.
• Elicit the plant defences through an antagonism

22. BIOFERTILIZER ORGANISMS
RHIZOBIUM
AZOSPIRILLUM
VA-MYCORRHIZA
BLUE GREEN ALGAE
AZOTOBACTER
PSB

24. Commericial production of biofertilizer
Firstly prepare the media- Rhizobium : Grown on Yeast
extract mannitol broth, Azotobactor: Grown on N-free
mannitol agar medium, Azospirillum : Grown on Dobereiner's
malic acid broth with NH4Cl (1g per liter)
Inoculate the appropriate strain(in flask).
Keep the (flask) under room temperature in rorates shaft
for 4-5days for,6-7 days,5-7 days.
Observed the growth of culture.This is also called as mother
Culture.

25. Mother Cultures

26. A LIST OF IMPORTANT MICROORGANISMS WITH
PRACTICAL/ POTENTIALAPPLICATION AS
BIOFERTILIZERS
ORGANISMS ACTIVITY ASSOCIATION, IF ANY USED IN CROPS
Rhizobium
(leguminosarum,
japonicum,
phaseoli,etc)
N2 –Fixation Symbiotic Legumes (pulses, oil
seeds, forage crops)
Azospirillum N2 –Fixation Associative Graminaceous crops
like wheat, rice,
sugarcane, jowar.

27. ORGANISMS ACTIVITY ASSOCIATION, IF
ANY
USED IN CROPS
Azotobacter N2 –Fixation Asymbiotic Wheat, rice,
vegetables.
Blue-green
algae
(Plectonema ,
Anabaena,
Noctoc, etc)
N2 –Fixation Asymbiotic Rice
Azolla-
Anabaena
complex
N2 –Fixation Symbiotic Rice
Phosphate
solubilizing
bacteria
(Thiobacillus,
Bacillus, etc.)
Phosphate
solubilization
Asymbiotic Many crops
Mycorriza
(Glomus)
Phosphate
solubilization
Associative Many crops,
including pulses

28. Bio-fertilizer Production and Commercially available bio-fertilizers
There is a long list of companies dealing with bio-fertilizer production
like
• National Fertlizer Limited Company,
• Niku Bio-Research Lab,
• Nitro Laboratories,
• Orgaman, Orrisa Agro Industries Corporation Ltd etc., are producing
bio-fertilizers.

29. ADVANTAGES OF BIOFERTILIZERS
• Increase the crop yield by providing nutrients to plants.
• They are safe and eco-friendly.
• Leaves no traces of toxins or harmful chemicals into soil and in
plants.
• Increases the fertility of the soil.
• They suppress diseases in plants as well as harmful
microorganisms is soil.
• Increase the nutrient uptake by the plants.
• They also produce growth hormones.
• They are safe to handle as compared to chemical fertilizers.
• Decreases the dependence on chemical fertilizers.
• Increases the nutritional quality of final product.

30. Disadvantages OF BIOFERTILIZERS :
Much lower nutrient density -- requires large amounts to get
enough for most crops.
Requires a different type of machine to apply than chemical
fertilizers.
Sometimes hard to locate in certain areas odor.

31. CONCLUSIONSAND FUTUREPROSPECTS
 The agrochemical industry is more sympathetic now to the concept of
bacterial inoculants than it has been previously. There is a genuine
interest in developing bacterial products that are reliable and that can
act as complements to chemicals already on the market
 Greenhouse crops are also primary targets for commercial inoculants
 Pioneering transgenic plants are already in the field expressing
insecticidal proteins of B. thuringiensis in cotton plants, making them
resistant to various insect pests.
 A gradual and modest increase in the use of bacterial inoculants is to
be expected.
 Agriculture in developed countries is definitely the major promoter of
microbial inoculants that are "environmentally friendly“.

32. REFERENCE
Text book of microbiology-R.P singh
Biotechnology-B.D singh
Biotechnology-U.Satyanaryan
Book microbiology-Prescott

33. Thank you