SCREENING OF COCOON SHELL OF INDIAN SILKWORMBREEDS/HYBRIDS OF BOMBYX MORI LINN., FOR FIBROIN PROTEIN

Fibroin is the silk protein synthesized by silk gland of Bombyx mori as a core material which is surrounded by sericin protein layer. Fibroin is an important protein having the properties of water absorbency, dyeing affinity, thermo tolerance, insulation and lusture. Fibroin protein is used for biomedical and cosmetic purposes particularly for human health care. The cocoon shells of silkworm, Bombyx mori of both sexes of twenty four bivoltine breeds (KA, CSR20, Kinshu, CSR8SL, CSR2SL, CSR18, CSR19, BMN, CSR5, Showa, 3HT, NB4D2, CSR23, CSR2, CSR4, 5HT, 8HT, B62, JPN8, B71, A60, D13, S5, B60), nine multivoltine breeds (PM, C. nichi, 96C, ND7, BL 67, 2000K, LMO, MAD, Moria), six bivoltine x bivoltine hybrids (CSR2 x CSR4, CSR4 x CSR2, CSR18 x CSR19, CSR19 x CSR18, D13 x S5, JPN8 x CSR4), one double hybrid (CSR2 x CSR27) x (CSR6 x CSR26) and one multivoltine x bivoltine hybrid (PM x CSR2) were taken to screen the fibroin protein content. The study revealed that the bivoltine breeds/hybrids contained more fibroin protein than in multivoltine breeds/ hybrids. In bivoltine, fibroin protein ranged from 71.7-80.3%, in multivoltine it was 72.2-78.5% and in hybrids it ranged from 72.9 to 80.4%.