Microbial inoculants defined, types, importance, advantages - Bioinoculant Technology

1. Bioinoculants-Definition, Types,
Importance, and Advantages
Presented by
Mr. VIJAY KARUPPIAH,
Assistant Professor,
Department of Microbiology,
Sacred Heart College,
Tirupattur.

2. Bioinoculants (or) Microbial inoculants
• Bioinoculants are the beneficial soil amendments that use
microbes for promoting plant growth and development.
• Microbial inoculants refer to formulations composed of Beneficial
microorganisms (bacteria, fungi, viruses and alga) that play an
important role in soil ecosystems for sustainable agriculture.
• Microbial inoculants are gaining importance for attaining sustainable
agricultural production systems. An increasing trend for the use of
microbial bioinoculants to accomplish sustainable agriculture has
been witnessed across the globe.

3. Microbial Relationship with plant systems
• Mutualistic (Symbiont and free-living forms) - Biofertilizers
• Commensalistic – Rhizosphere and Phyllosphere commensal
microflora as nutrient cyclers in soil.
• Amensalistic - Antagonistic to invading pathogens – Biopesticides

4. Various spheres in plant systems

5. Various spheres in plant systems

6. Plant Microbiome by Samanthi, 2019

7. Microbial Inoculants
• Microbial Inoculants are able to carry out the Plant growth promotion
(Biofertilizers), Pest control (Biopesticides) and Plant disease control
(Biocontrol agents-Fungicides).
• Microbial inoculants have the ability to minimize the negative impact of
chemical input and consequently increase the quantity and quality of
agricultural products. Microbial inoculants are eco-friendly and deliver
plant nutrients to plants in a more sustainable manner. Microbial
inoculants can help to reduce the chemical fertilizer application.

8. Types of microbial inoculants
• Nitrogen fixing bacteria – Azospirillum sp., Rhizobium sp.,
Azotobacter sp., Achromobacter sp., Gluconacetobacter
diazotrophicus, Azorhizobium sp., Sinorhizobium sp., Frankia sp.,
Azoarcus sp., Mesorhizobium sp., Allorhizobium sp.,
Bradyrhizobium sp., Burkholderia sp., and Herbaspirillum sp.
• Phosphate solubilizers – Pseudomonas sp., Bacillus sp.,
Arthrobacter sp., Rhodococcus sp., Serratia sp., Gordonia sp.,
Phyllobacterium sp., Delftia sp., Azotobacter sp., Xanthomonas
sp., Chryseobacterium sp., Enterobacter sp., Pantoea sp., Klebsiella
sp., Xanthobacter agilis, Vibrio proteolyticus and Rhizobium
leguminosarum.
• Phosphate mobilizers – Mycorrhizal fungi

9. Types
• Biocontrol agents – Pseudomonas fluorescence, Bacillus subtilis,
Trichoderma viride, Trichoderma harzianum and Pochonia
chlamydosporia, Achromobacter kerstersii (Vijay et al., 2020), etc.
• Biopesticides
• Entomopathogenic bacteria - Bacillus thuringiensis and Paenibacillus popilliae
• Entomopathogenic fungi - Beauveria bassiana, Metarhizium anisopliae, Isaria
fumosorosea, Lecanicillium lecanii, Purpureocillium lilacinum, Entomophaga sp.
and Neozygites sp.
• Entomopathogenic virus – Helicoverpa zea Single-enveloped
Nucleopolyhedrovirus (HzSNVP), Spodoptera exigua Multi-enveloped
Nucleopolyhedrovirus (SeMNPV) and Cydia pomonella Granulovirus (CpGV).

10. • Effective microorganisms (EM) – Mixture of Photosynthetic bacteria
(Rhodopseudomonas palustris) + Lactic acid bacteria (Lactobacillus casei) +
Yeast (Saccharomyces cerevisiae) + Other beneficial microorganisms
existing in environment.
• Siderozote (Vijay et al., 2022) – Mixture of siderophores producing
rhizobacteria in phosphate buffer.
• Mycoclear (Vijay et al., 2022) - Mixture of lipopeptides producing
rhizobacteria in phosphate buffer.
• Mycodot - Mixture of mycophagous bacteria as formulate.
• Fusostat – Mixture of chitinase producing rhizobacteria.
Types

11. Importance of Microbial Inoculants to plants
• Improves plant nutrition and promotes plant growth.
• Stimulates the production of Plant growth promoting hormones
(Indole acetic acid and Gibberellins)
• Manage soil biology, soil structure and organic wastes.
• Manipulate the Rhizosphere and Phyllosphere region of plants.
• Induce Induced Systemic Resistance (ISR), Systemic Acquired
Resistance (SAR) and Integrated Pest Management (IPM).
• Enhances plant production and protection.
• Recycling of vital elements through Biogeochemical cycle.

12. • Suppress the Soil borne pathogens.
• Reduces the concentration of toxic substances including Pesticides
and Heavy metals in soil.
• Enhances the Photosynthesis process in plants.
• Promotes Germination, Flowering and Fruiting in plants.
• Fixation of atmospheric nitrogen.
• Solubilization of Insoluble nutrients in soil.
• Mobilization of various soil nutrients in soil.
• Prevent plants from Phytopathogens and Insect pests.
• Produces polysaccharides to improve Soil aggregation
• Prevent plants from high temperature, salinity and desiccation.
Importance of Microbial Inoculants to plants

13. Advantages of Biofertilizers over
Chemical fertilizers
• Biofertilizers have replaced the chemical fertilizers as chemical
fertilizers are not beneficial for the plants. Chemical fertilizers
decrease the growth of the plants and make the environment
polluted by releasing harmful chemicals.
• Plant growth can be increased if biofertilizers are used, because
they contain natural components which do not harm the plants.
• If the soil will be free of chemicals, it will retain its fertility
which will be beneficial for the plants as well as the environment,
because plants will be protected from getting any diseases and
environment will be free of pollutants.
• Biofertilizers destroys harmful components from the soil which
cause diseases in the plants.

14. • Biofertilizers are not costly and even poor farmers can make use
of them.
• Biofertilizers provides plant nutrients at very low cost.
• Biofertilizers helps for the survival of beneficial microorganisms
in soil.
• Biofertilizers helps to get high yield of crops by making the soil
rich with nutrients and useful microorganisms necessary for the
growth of the plants.
• Biofertilizers are also known to provide better nourishment to
plants than chemical fertilizers.
Advantages of Biofertilizers over
Chemical fertilizers

15. References
• Subba Rao N.S. 1999. Soil Microbiology, 4th Edition, Oxford and
IBH Publishing Co.Pvt. Ltd., New Delhi, India.
• Saranraj, P and Sivasakthivelan, P. 2020. Text Book of
Bioinoculants Technology. 1st Edition, JPS Scientific Publications,
India.
• Atlas, R.M and R. Bartha. 1998. Microbial Ecology. Fundamentals
and Applications, 4th Edition, Red Wood City. C.A. Benjamin.
• Mahendra K. Rai. 2005. Hand book of Microbial Biofertilizers, The
Haworth Press, Inc. New York.