The eggs of commercial crossbreed PM x CSR2 race of B. mori was obtained from a National Silkworm Seed Organization (NSSO), Bangalore. The eggs were surface sterilized by dipping in 2% formaldehyde for 15 min at room temperature, washed several times with the sterile distilled water, again dipped in 70% alcohol for 10 min, followed by rinsing with sterile distilled water. The surface sterilization of eggs was confirmed by inoculating
the eggs on the nutrient agar and incubating at 25 _C and 37 _C for 4 days to ensure complete sterilization of the egg surface. The eggs were then homogenized in 1000 ml sterile double distilled water and the homogenate was inoculated on nutrient agar. For the control group, sterile distilled water was spread on the nutrient agar. Inoculated plates of both the groups were incubated at 37 _C for 96 h. The spore forming bacterial colonies developed on
the nutrient agar inoculated with egg homogenate was sub cultured, purified and identified
as B. subtilis.