Microbes can be used as biofertilizers and biopesticides in agriculture. Biofertilizers include nitrogen-fixing bacteria like Rhizobium, phosphate-solubilizing fungi, and mycorrhizal fungi. They are applied to seeds, soil, or planting material. Biopesticides contain microorganisms like Bacillus thuringiensis (for insects) or Trichoderma fungi (for plant pathogens) and can be applied as sprays. Examples of other types discussed include bioinsecticides, biofungicides, bionematicides, and bioherbicides, which contain fungi, bacteria, viruses or nematodes to control specific pest problems.

1. Microbes in human welfare: biofertilizers,
and biopesticides
Dr. S. PARTHASARATHY, M.Sc. (Agri)., Ph.D.
Assistant Professor (Plant Pathology)

3. Biofertilizers
• 'Biofertilizer' is a substance which contains living microorganisms
which, when applied to seed, plant surfaces, or soil, colonizes the
rhizosphere or the interior of the plant and promotes growth by
increasing the supply or availability of primary nutrients to the host
plant.
• Main part of INSS (Integrated Nutrient Supply System)
• Biofertilizers add nutrients through the natural processes of fixing
atmospheric nitrogen, solubilizing phosphorus, and stimulating plant
growth through the synthesis of growth promoting substances.

4. Group Sub-group
Nitrogen fixing Free-living
Symbiotic
Associative
Endophyte
Phosphorus (microphos) Phosphate solubilizing
Phosphate mobilizing
Potassium Potassium solubilizing
Potash mobilizing
Micronutrients Silicate and zinc solubilizing
Sulfur-solubilizing
Iron transformation
Manganese transformation
Copper transformation
Growth promoting Plant growth promoting rhizobacteria
Drought and saline tolerance Pink Pigmented Facultative Methanotrophs
Types of Biofertilizers

5. Group Sub-group Examples
Nitrogen
fixing
Free-living Important: Anabaena azollae, Azotobacter
chroococcum, Beijerinkia, Nostoc, Bacillus polymyxa,
Clostridium, and Klebsiella
Minor: Derxia, Aulosira, Cylindrospermum,
Tolypothrix, Stigonema, Rhodopseudomonas,
Rhodospirillum, Desulfovibrio, and Chromatium
Symbiotic Rhizobia (Rhizobium, Bradyrhizobium,
Sinorhizobium, Azorhizobium Mesorhizobium
Allorhizobium), Frankia, Anabaena azollae, and
Trichodesmium
Associative Important: Azospirillum spp. (A. brasilense, A.
lipoferum, A. amazonense, A. halopraeferens, and A.
irakense), Herbaspirillum spp., Acetobacter
diazotrophicus,
Minor: Azoarcus spp., Alcaligenes, Bacillus,
Enterobacter, Klebsiella, and Pseudomonas
Endophyte Gluconacetobacter diazotrophicus (Sugarcane)

6. EFFECTIVE ROOT
NODULES CAUSED BY
RHIZOBIUM

7. Azospirillum lipoferum
Azotobacter chroococcum

8. Formation of chocolate brown coloniesBrown pigmentation of
G. diazotrophicus
Cavalcantae and Doberiner – 1988 reported this new endophytic N2 fixer
Endophytic N2 fixers - Found to occur on large numbers in roots, stem &
leaf of sugarcane & other sugar rich crops
Gluconacetobacter diazotrophicus

10. Group Sub-group Examples
Phosphorus
(microphos)
Phosphate
solubilizing
Important: Bacillus megaterium var.
phosphaticum, Gluconacetobacter
diazotrophicus, B. subtilis, B. circulans, B.
polymyxa, Pseudomonas striata, Penicillium
spp., Aspergillus awamori & Trichoderma.
Minor: Rhizoctonia solani, Rhizobium,
Burkholderia, Achromobacter, Agrobacterium,
Microccocus, Aereobacter, Flavobacterium, and
Erwinia
Phosphate
mobilizing
Arbuscular mycorrhiza (Glomus sp., Gigaspora
sp., Acaulospora sp., Scutellospora sp., and
Sclerocystis sp.)
Ectomycorrhiza (Laccaria spp., Pisolithus spp.,
Boletus spp., Amanita spp.),
Ericoid mycorrhizae (Pezizella ericae), and
Orchid mycorrhiza (Rhizoctonia solani)

11. Bacillus megatherium Pseudomonas striata
Glomus Arbuscule

12. Group Sub-group Examples
Potassium
Micronutrients
Potassium
solubilizing
Bacillus edaphicus, Bacillus circulans, Bacillus
brevis, Bacillus coagulans, Burkholderia cepacia,
Burkholderia metallica, Pseudomonas otitidis,
Torulopsora globosa and Paenibacillus
glucanolyticus
Potash
mobilizing
Bacillus mucilaginosus, Pseudomonas gessardii
and Enterobacter asburiae
Silicate and
zinc solubilizing
Bacillus subtilis, Gluconacetobacter diazotrophicus,
Thiobacillus thioxidans, Rhizobium daejeonense,
Pantoea dispersa, Pantoea agglomerans and
Saccharomyces sp.
Sulfur-
solubilizing
Thiobacillus thioxidans, Beggiatoa, and
Desulfovibrio
Iron
transformation
Gallionella, Ferribacterium, and Leptothrix
Manganese
transformation
Aerobacter, Cornybacterium, Flavobacterium, and
Cladosporium
Copper
transformation
Desulfovibrio, Clostridium, and Escherichia

13. Burkholderia cepacia
Bacillus mucilaginosus (Paenibacillus mucilaginosus)

14. Bacillus subtilis
Thiobacillus thioxidans Flavobacterium Escherichia

15. Group Sub-group Examples
Growth
promoting
Plant growth
promoting
rhizobacteria
Important: Pseudomonas fluorescens,
Azotobacter, Bacillus, Rhizobium,
Bradyrhizobium, and Streptomyces.
Minor: Agrobacterium, Achromobacter,
Alcaligenes, Arthrobacter, Actinoplanes,
Erwinia, Enterobacter, Amorphosporangium,
Cellulomonas, Flavobacterium, and
Xanthomonas.
Drought and
saline
tolerance
Pink Pigmented
Facultative
Methanotrophs
Methylobacterium extorquens,
Methylobacterium
dichloromethanicum, Methylobacterium
rhodinum
Pseudomonas fluorescens Methylobacterium extorquens

16. Methods of Application of Biofertilizers
Seed Treatment: 200 g of biofertilizer is suspended in 300- 400 mL of water
and mixed gently with 10 kg of seeds using an adhesive like gum acacia,
jiggery solution, etc. The seeds are then spread on a clean sheet/cloth under
shade to dry and used immediately for sowing.
Seedling Root Dip: Recommended biofertilizers are mixed in this water and
the roots of seedlings are dipped for 8-10 h and transplanted.
Soil Treatment: 4 kg each of the recommended biofertilizers is mixed in 200
kg of compost and kept overnight. This mixture is incorporated in the soil at the
time of sowing or planting.
Sett Treatment: Suspended and mixed thoroughly 15 kg bio fertilizer for one
hectare in 300 lit of water. Treat cane sett by dipping in this suspension before
planting.

17. Biopesticide are certain types of pesticides derived from such natural
materials as animals, plants, bacteria and certain minerals.
In commercial terms, biopesticides include microorganisms that control
pests (microbial pesticides), naturally-occurring substances that control
pests (biochemical pesticides), and pesticidal substances produced by
plants containing added genetic material (plant-incorporated
protectants).
Types of Microbial Biopesticides (broadly called as biocontrol agents)
• Bioinsecticide (broadly called as biopesticides)
• Biofungicide (broadly called as antagonists)
• Bionematicide
• Bioherbicide
Microbial Biopesticide

18. Bioinsecticides Target pest
Fungi
Beauveria bassiana Aphids, beetles, coffee berry borer, grasshoppers, thrips, white
grubs, whiteflies, and many lepidopteran pests
Beauveria brongniartii White grubs
Metarhizium anisopliae Aphids, beetles and their grubs, leaf and plant hoppers,
termites, pod borer, cutworms and other lepidopteran pests
Lecanicillium (=Verticillium) lecanii Aphids, mealybugs, mites, scale insects, thrips, mites,
whiteflies and other homopterans
Hirsutella thompsonii Mites especially eriophids in coconut
Isaria fumosorosea (=Paecilomyces
fumosoroseus)
Aphids, thrips, jassids, whiteflies and mites
Bacteria
Bacillus thuringiensis var. kurstaki Lepidopteran pests
Bacillus thuringiensis subsp. israelensis Mosquitoes, black fly and fungus gnat larvae
Lysinibacillus sphaericus
Bacillus thuringiensis subsp. galleriae Bollworms, diamondback moth and other Lepidoptera
Virus
Nuclear polyhedrosis virus of H. armigera (HaNPV) Helicoverpa zea and H. armigera
Nuclear polyhedrosis virus of S. litura (SlNPV) Spodoptera litura and S. exigua
Granulosis virus Leaf folder, Yellow top borer
Cytoplasmic polyhedrosis virus Helicoverpa armigera
Pox virus Amsacta moorei
Entomopathogenic Nematodes
Steinernema carpocapsae, Steinernema
thermophilum, Heterorhabditis indica
Root grubs, cutworms, root weevils, various lepidopterans and
termites
Heterorhabditis bacteriophora Root and foliar pests

19. Beauveria bassiana
Metarhizium anisopliae

20. Bacillus thuringiensis var. kurstaki

21. Biofungicides Target diseases
Fungi
Ampelomyces quisqualis Powdery mildew
Chaetomium globosum Damping off
Darluca filum Rust
Trichoderma hamatum, T. harzianum, T.
koningii, T. polysporum, T. viride
Root and soil borne diseases
Verticillium hemileiae Coffee rust
Bacteria
Agrobacterium radiobacter Crown gall
Bacillus subtilis Soil borne and foliar diseases
Pseudomonas fluorescens Soil borne and foliar diseases
Streptomyces diastaticus Soil borne and foliar diseases
Virus
Bacteriophages Foliar bacterial diseases

22. Trichoderma viride
Chaetomium globosum Ampelomyces quisqualis
Darluca filum
Pseudomonas fluorescens

23. Bionematicides Target nematodes
Fungi
Purpureocillium lilacinum
(= Paecilomyces lilacinus)
Plant pathogenic nematodes
Pochonia chlamydosporia (=Verticillium
chlamydosporium)
Plant pathogenic nematodes,
especially root-knot nematodes
Bacteria
Pasteuria penetrans Plant pathogenic nematodes, especially root-
knot nematodes
Pseudomonas aeruginosa Plant pathogenic nematodes, especially root-
knot nematodes
Pseudomonas fluorescens Plant pathogenic nematodes, especially root-
knot nematodes
Bacillus subtilis Plant pathogenic nematodes, especially root-
knot nematodes

24. Purpureocillium lilacinum (= Paecilomyces lilacinus)
Pochonia chlamydosporia
(=Verticillium chlamydosporium)
Pasteuria penetrans

25. Bioherbicides Target weeds
Fungi
Colletotrichum gloeosporioides
Biomal
Northern jointwetch, Round leave-mallow,
Dodders, Hakea, Velvet leaf
Phytophthora palmivora Milkweedvine
Alternaria destruens Dodders
Puccinia canaliculata Yellow nut sedge
Cercospora rodmanii Water hyacinth
Bacteria
Ralstonia solanacearum Tropical soda apple
Colletotrichum gloeosporioides Phytophthora palmivora

26. Thank You