Isolation of Bacillus thuringiensis for the Production of Insecticidal Endotoxin

Abstract

Pakistan’s economy greatly relies on the agriculture sector as it contributes 24 percent to the GDP and absorbs 50 percent labor force. Hence, this sector needs to take steps to achieve a high yield and good quality crops. As the world has adopted the advancement in the agriculture sector by producing GMO plants having desirable traits, usage of synthetic pesticides, insecticides, and other adopting measures to produce a high yield of crops. The present study aimed to isolate an indigenous thermophilic bacterium namely, Bacillus thuringinesis from soil samples and to screen and optimize its insecticidal activity to evaluate its effective application as a bioinsecticide. We collected 5 soil samples from different vicinities of Karachi and Mardan. Standard microbiological techniques were adopted, and bacterial isolates were selected based on morphological characteristics. A total of 53 colonies were isolated and microscopic examination showed 37 isolates as spore former. These 37 isolates were selected for bioassay against Tribolium casteneum. During bioassay, 4 isolates (SMA 56, SMB 77, SMB 80, and SMB 82) showed a more than 50% mortality rate.