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Gut microflora of the larva of silkworm, Bombyx mori

Published online by Cambridge University Press:  19 September 2011

S. Kalpana
Affiliation:
Department of Environmental Sciences, Bharathiar University, Coimbatore-641 046, India
A. A. M. Hatha
Affiliation:
Department of Environmental Sciences, Bharathiar University, Coimbatore-641 046, India
P. Lakshmanaperumalsamy
Affiliation:
Department of Environmental Sciences, Bharathiar University, Coimbatore-641 046, India
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Abstract

The quantitative and qualitative changes of bacterial flora associated with the silkworm (Bombyx mori) at different stages of its life cycle were studied. Larvae reared on mulberry leaves were dissected and their bacterial populations counted after a 3-day incubation period at 28 ± 2°C. The results showed a higher heterotrophic bacterial population in the fourth and the fifth instars, which coincide with the active feeding stage of the larvae. The similarity of the genera observed in the digestive tract and that observed on the leaves fed to the larvae suggests colonisation of food microflora in the gut following ingestion. The bacteria inhabiting the gut of silkworm were found to be elaborating amylase, caseinase, gelatinase, lipase and urease. The highest percentage of isolates were protease producers followed by lipid and polysaccharide splitters. The results indicate that the bacterial flora play an important role in the digestion of ingested food material.

Résumé

Des changements quantitatifs et qualitatifs de la flore bacérienne associée au ver-à-soie ont été étudiés à différents stades de son cycle de vie. Des larves elevées sur des feuilles du mûrier ont été disséquées et leur flore bactérienne a été comptée après 3 jours d'incubation à 28 ± 2°C. Les résultats montrent une population bactérienne hautement hétérotrophique chez les 4ème et 5ème stades qui coïncident aux stades nourriciers de la larve. La similarité des genres observés au niveau du tractus digestif et sur les feuilles suggére la colonisation de la microflore de la nourriture au niveau des intestins par suite de l'ingestion. On a trouvé que les bactéries peuplant les intestins du ver-à-soie élaborent l'amylase, la caséinase, la gélatinase, la lipase et l'uréase. Un plus grand pourcentage des isolats ont été des producteurs de protéase, suivis de séquenceurs de lipides et de polysaccharides. Les résultats indiquent que la flore bactérienne joue un rôle important dans la digestion de la nourriture ingérée.

Type
Research Articles
Copyright
Copyright © ICIPE 1994

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