Application of microbial biopesticide against different type of.pptx

application of microbial pesticide

1. Application of microbial pesticide against different type of pathogen Submitted by- P Sobhangi M.Sc. Industrial microbiology (2 nd semester)

2. Introduction The United States Environmental Protection Agency (EPA) defines biopesticides as, “ certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals ”. The most commonly used biopesticides are living organisms, which are pathogenic for the pest of interest.

3. Microbial biopesticide Microbial biopesticides are composed of microscopic living organisms (viruses, bacteria, fungi, protozoa, or nematodes) or toxin produced by these organisms Applied as conventional insecticidal sprays, dusts, or granules. Their greatest strength is their specificity as most are essentially nontoxic and non pathogenic to animals and humans. Microbial pesticides includes insecticides, fungicides, herbicides and growth regulators of microbial origin.

4. Bacteria: To be effective, they must come into contact with the target pest and may be required to be ingested. In insects , bacteria disrupt the digestive system by producing endotoxins that are often specific to the particular insect pest When used to control pathogenic bacteria or fungus, the bacterial biopesticide colonizes on the plant and crowds out the pathogenic species.

5. Pseudomonas fluorescens , a bacterium that produces secondary metabolites with antifungal properties. Certain strains of P. fluorescens can suppress the growth of plant pathogenic bacteria such as Pseudomonas syringae , which causes diseases in a variety of crops including tomatoes, beans, and stone fruits. By colonizing the plant rhizosphere and outcompeting pathogenic bacteria for resources, P. fluorescens biopesticides contribute to the maintenance of plant health and productivity in agricultural systems.

6. The most widely used microbial pesticides are subspecies and strains of B. thuringiensis (Bt), accounting for approximately 90% of the biopesticide market in the USA. One of the most widely recognized microbial biopesticides is Bacillus thuringiensis (Bt), a bacterium known for its production of insecticidal proteins . These proteins specifically target and disrupt the digestive systems of certain insect pests, including caterpillars, beetles, and mosquitoes , leading to their mortality. Bt biopesticides -control pests such as corn borer, cotton bollworm, and mosquito larvae

7. Fungi Beauveria bassiana is a naturally occurring entomopathogenic fungus that infects and kills a wide range of insect pests, including beetles, flies, and caterpillars . Beauveria -based biopesticides . By attaching to the insect's cuticle, penetrating its integument, and proliferating in the hemocoel , B. bassiana causes systemic infection and eventual death of the pest. A re commonly used in organic farming and greenhouse production to manage pest populations without harming beneficial insects

8. Trichoderma spp . are another group of fungi widely used as biopesticides for controlling plant pathogenic fungi. These fungi colonize the rhizosphere and root surfaces of plants , where they establish beneficial interactions and compete with pathogenic fungi for nutrients and space. Trichoderma spp. also produce secondary metabolites such as enzymes and antibiotics that inhibit the growth of pathogens such as Fusarium spp., Rhizoctonia spp., and Botrytis cinerea . By enhancing plant growth and suppressing disease development, Trichoderma -based biopesticides contribute to sustainable agriculture and reduce reliance on chemical fungicides.

9. Nematodes

10. Virus Nucleopolyhedroviruses (NPVs) : These viruses infect and kill certain insect pests while leaving non-target organisms unharmed. For example, the Helicoverpa armigera nucleopolyhedrovirus ( HearNPV ) is used to control cotton bollworms in agriculture. Baculoviruses : Several baculoviruses are commercially available for controlling insect pests like gypsy moths, codling moths, and cabbage loopers . They are applied as microbial pesticides by spraying formulations containing viral particles onto target pests.

11. Protozoa: Diverse group of organisms comprising around 1000 species attacking invertebrates including insect species and are commonly referred as microsporidians . Host specific and slow acting, producing chronic infections. The spore formed by the protozoan is the infectious stage and has to be ingested by the insect host for pathogenicity . The spore germinates in the midgut and sporoplasm is released invading the target cells causing infection of the host.

12. Nosema pyrausta is another beneficial microsporidian that reduces fecundity and longevity of the adults and also causes mortality of the larvae of European corn borer. Bdellovibrio bacteriovorus : This predatory bacterium preys on other bacteria , including pathogenic species such as Salmonella and Escherichia coli . It can be used as a biocontrol agent to reduce the populations of these pathogens in environments like water bodies and food processing facilities.

13. Advantages Environmental sustainability Target specificity Reduced risk to non-target organisms Resistance management Disadvantages high specificity slow speed of action their requirement of suitable condition for their survival

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