Silkworm pupae is one of the major by-products of silk industry and considered as waste in silk reeling. Reelers after reeling out silk are generally used to throw the dead pupae at the outskirts of the city, creating nuisance and health hazards. Hence, disposal of silkworm pupae is a very big challenge. But this pupae contains numerous biological constituents which could be utilized in many industries including pharmaceuticals.
Aim of the study: Silkworm pupae are used to extract chitosan which is having many biological properties. The present study aimed to evaluate in vivo antibacterial effect of chitosan against bacterial pathogens, Staphylococcus aureus and Bacillus thuringiensis in silkworm.
Materials and Methods: Chitosan was extracted by deproteinization, demineralization and deacetylation. The different concentrations ranged from 0.5 to 4.5 percent were used for this study. Antibacterial bioassay was conducted and observations on larval mortality, larval weight, cocoon weight and shell weight were calculated.
Results: The antibacterial activity of chitosan extracted from silkworm pupae were maximum with 2.5 per cent against Staphylococcus aureus and Bacillus thuringiensis and economic parameters were also found to increased when compared to negative control.
Conclusion: The present study concluded that chitosan extracted from silkworm pupae showed antibacterial activity, its application to silkworm reduced larval mortality which indicated disease resistance and increased economic parameters. The unused pupae was effectively reutilized and converted into useful bioproduct.