Isolation of Bacillus thuringiensis from Different Localities in Egypt

A total of 14 isolates of Bacillus thuringiensis were obtained from 25 soil samples collected from 5 Governorates in Egypt. The isolates were identified according to morphological features and physiological characteristics such as; anaerobic growth, fermentation of glucose, Voges-Proskauer reaction, protein hydrolysis, citrate utilization as a sole source of carbon and reduction of nitrate. From 68 selected colonies having Bacillus-form, 14 were able to produce bipyramidal crystals, forming white, rough colonies, spread out and expand very quickly over the plate. Growing under anaerobic conditions, produced acid from glucose, hydrolyzed gelatin, reduced nitrate, utilized citrate and gave positive reaction for acetylmethyl carbinol test. Such results proved that, these 14 isolates belong to Bacillus thuringiensis.