Withdrawn: Diversity of Bacterial Flora in the Mid Gut of Fifth Instar Larvae of Silk Worm Bombyx mori (L) (Race: PM X CSR2)

Abstract

Silk worm, Bombyx mori (L.) (Lepidoptera: Boimbycidae) deserve significant feature with reference to silk synthesis and therefore it have been domesticated and widely used for silk production. Being a lepidopteran insect, it exhibits a typical life cycle, which includes the life stages like: egg, larval instars, pupa within a silky cocoon and adult moth. The larval instars feed voraciously on mulberry leaves, carbohydrate contents of which are composed of pectins, xylan, cellulose and starch. Some of the digestive enzymes that degrade these carbohydrates might be produced by mid gut bacteria. Eleven isolates were obtained from the digestive tract of multivoltine, cross breed silk worm, Bombyx mori (L) (PM x CSR2). The isolates include: the Gram positive Bacillus circulans and Gram negative Proteus vulgaries, Klebsiella pneumonia, Escherichia coli, Cittrobacter freundii, Serratia liquefaciens, Enterobactor sp., Pseudomonas fluorescens, P. aeruginosa, Aeromonas sp. and Erwinia species. The three of these isolates, P. vulgaris, K. pneuomonae, C. freundii were found belonging to cellulolytic and xylanolytic group. P. fluorescens and Erwinia sp. were pectinolytic. The species K. pneuomniae was found degrading the starch. Aeromonas sp. was able to utilize the CMcellulose and xylan. S. liqquefaciens was able to utilize three polysaccharides including CM cellulose, xylan and pectin. B. circulans was able to utilize all four polysaccharides with different efficacy. The mid gut of fifth instar larvae of silk worm, Bombyx mori (L) has an alkaline pH and of the isolated bacterial strains were found to grow and degrade polysaccharides at alkaline pH. The cellulolytic bacteria were found to increase with each instar.The nutritional contribution of mid gut microbiota and endosymbionts may be of several forms including: improved digestion efficiency; improved ability to live on suboptimal diets; acquisition digestive enzymes and the provision of vitamins. KEYWORDS: