Bacterial isolates and cultivation conditions
A total of 190 samples of B. thuringiensis were studied. All
samples were found in the zoo. To perform serological studies, the
bacteria were grown at a temperature of 37°C for a period of 5 hours.
Nutrient broth with a pH value of 7.5 was used for this purpose. The
broth consisted of 15 g of meat extract, the same amount of polypeptone,
as well as 1000 ml of distilled water and 3 g of sodium chloride.
Bacterial growth was carried out on nutrient medium (nutrient agar
consisting of 1 liter of broth, 30 g of agar). The temperature regime
was 28°C and the cultivation time was 5-6 days. This was necessary for
tests on pathogenic activity for insects, as well as for observations of
sporulated cultures using a microscope.