• Applied Biological Chemistry
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• v.38 no.6
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• pp.485-489
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• 1995

The medium additives such as fatty acid, lipid, mannose, folic acid, $CaCl_2$ were examined to enhance recombinant ${\beta}-galactosidase\;({\beta}-gal)$ production in T-flask and air-lift bioreactor. The addition of each component. such as cholesterol, tocopherol, tricaprylin, mannose and folic acid at AcNPV infection of Tn5B1-4 cells enhanced ${\beta}-gal$ production, whereas the addition of $CaCl_2$ did not increase ${\beta}-gal$ production. The recombinant ${\beta}-gal$ production using the infection medium supplemented with a mixture of 0.34 mM cholesterol, 2.2 mM mannose and 0.045 M folic acid was enhanced 2 fold in an air-lift bioreactor, compared to the basal medium.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.1
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• pp.29-34
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• 2006

A breeding programme was initiated during 2001 utilizing two polyvoltine silkworm breeds viz. $BL_{69}$, an evolved breed tolerant to high temperature and MAR, comparatively resistant to Bombyx mori nuclear polyhedrosis virus (BmNPV) with the objective to develop robust polyvoltine breeds and hybrids. The breed $NP_1$ was developed by exposing the fifth instar larvae to high temperature $(36{\pm}1^{\circ}C)$, high Relative Humidity ($85{\pm}5%$ R.H.) and inoculating third instar larvae with BmNPV inoculum. At $F_{12}$, the breed was tested for hybrid forming ability utilizing six bivoltine silkworm breeds viz. $CSR_2,\;CSR_4,\;CSR_{17},\;CSR_{18},\;CSR_{19}\;and\;NB_4D_2$. The hybrid $'NP_1{\times}CSR_{17}'$ exhibited its superiority by recording 97.2% survival, 1.892 g cocoon weight, 0.406 g cocoon shell weight, 21.5% cocoon shell ratio, 16.6% raw silk percentage and 890 m filament length whereas the control $(PM{\times}CSR_2)$ has recorded 90.2% survival, 1.599 g cocoon weight, 0.304 g cocoon shell weight, 18.9% cocoon shell ratio, 13.1 % raw silk percentage and 768 m filament length. Commercial exploitation of the new $polyvoltine{\times}bivoltine$ hybrid in sericulture industry has been discussed.

• Journal of Sericultural and Entomological Science
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• v.44 no.2
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• pp.69-73
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• 2002

For the practical use of nuecin protein, we tried to overexpress nuecin using Bm5 insect cell and Bombyx mori. We inserted nuecin cDNA into pBm10po1-Xa vector derived from B. mori nuclear polyhedrosis virus (BmNPV), and expressed in Bm5 cells and B. mori respectively. SDS-PAGE and Northern blot analysis showed an expressed of the protein when baculovirus expression vector system (BEVS) was used. The amount of intracellular protein is abundant, but the amount of extracellular protein is poor. The results suggest that the biologically active nuecin protein produced by using BEVS is poor because incresed level of misfolded nuecin by the strong promoter, polyhedrin and p 10 of BEVS, decrease the level of free chaperons and foldases by binding with them.