DISEASE RESISTANCE IN SILKWORM, BOMBYX MORI. Ganesh, A., S. Bhuvaragavan and S. Janarthanan. Department of Zoology, University of Madras, ...
BACILLUS SUBTILIS BIOFILM AS IMMUNOSTIMULANT FOR DISEASE RESISTANCE IN SILKWORM, BOMBYX MORI
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Ganesh, A., S. Bhuvaragavan and S. Janarthanan Department of Zoology, University of Madras, Guindy Campus, Chennai-600025
1. Introduction 10
X 106 Cells/ml of Hemolymph
Silkworms are affected by viral, bacterial, fungal and protozoan diseases throughout the year which have an effect on the sericulture industry. Immunostimulants are used to induce the activation of immune system of an organism to respond against it once after the ingestion. In recent years, the use of live or killed bacteria as an immunostimulant has been increasing. Biofilms are dense and sessile communities of microbial cells. These communities differ both morphologically and physiologically from free-living bacteria. Therefore, biofilms are the source of bacteria in more numbers and it could be used as immunostimulants after suitable inactivation methods.
II. Influence of B. subtilis biofilm on cellular population in the hemolymph of silkworm B. mori.
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Different hemocyte types were observed under phase contrast microscope (200X)
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Fig.3 : Hemocyte population in the hemolymph of silkworm stimulated with biofilm of B.subtilis
III. Effect of B. subtilis biofilm stimulation on antimicrobial activity in the silkworm B. mori 1.0
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2. Methods
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Fig.1:Variations in the quantity of hemolymph protein in the biofilm stimulated silkworm from the control larvae
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Fig.4 : Antibacterial activity of hemolymph against B. thuringiensis in the silkworm fed with biofilm of B. subtilis 100
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Fig.5 : Antibacterial activity of hemolymph against the E.coli in the silkworm fed with biofilm of B. subtilis
4. Conclusions
• The results of our study revealed that biofilm of B. subtilis fed to silkworms showed improved immune system than control. 50 • The results were comparable with previous studies on immunostimulants such as LPS. The biofilm is rich in carbohydrates. • This study conclude with 0 1 2 3 statement that biofilm of Bacillus subtilis could be Days immunostimiulant to the Fig.6 : NPV disease resistance of silkworm Bombyx mori . silkworm B.mori stimulated by B. subtilis biofilm.
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Fig. 2: Phenoloxidase activity of hemolymph in the silkworm B. mori fed with biofilm of B. subtilis
5. References 1. Lowry, O.H., Rosebrough, N.J., Farr A.L. and Randall R.J. 1951. Protein measurement with the Folin Phenol reagent. Journal of Biology and Chemistry. 193: 265-275. 2. Soderhall, K., Smith, V.J., 1983. Separation of the haemocyte populations of Carcinus maenus and other marine decapods, and prophenoloxidase distribution. Developmental and Comparative Immunology. 7: 229-239. www.p osterse www.postersession.com ssion.c om
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Amount of hemolymph protein (mg/ml)
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I. Influence of B. subtilis biofilm on humoral immune system in Bombyx mori
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3. Results
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Absorbance OD at 450nm
Influence of Bacillus subtilis biofilm on the silkworm Bombyx mori immune system was examined by the following methods: Quantification of protein (Loewry et al., 1951) Estimation of Phenoloxidase activity (Soderhall and Smith., 1983) Total hemocyte counts in the hemolymph Antimicrobial activity of silkworm hemolymph Viral disease resistance of silkworm B. mori
