Isolation and Identification
of Bacillus thuringiensis (Bt) Toxin Gene
from Local Isolates in Egypt

Bacillus thuringiensis (Bt) is a naturally occuring, soil borne organism that has gained recent popularity for its ability to control certain insect pests in a natural environmentally friendly manner.

Bacterial agents, like Bt, are effective in controlling insects in the larva stage only. The larva stage in an insect’s life cycle is the stage during which most of the feeding occurs. Since Bt must be ingested to work, the insect must be controlled during the larval stage. The larval stage is the stage in which the insect appears worm or caterpillar-like.

There are different strains or varieties of Bt available that have been selected for the control of specific insects. Bt variety kurstaki (BTK) controls the European corn borer, tomato hornworms, fruitworms, cabbageworm, cabbage looper, spring and fall cankerworm, spruce budworm and other caterpillar-like larvae. Bt variety israelensis (BTI) controls mosquitos, black flies and fungus gnats. Bt subsp. aegypti (C18), isolated at AGERI, controls potato tuber moth larvae, Egyptian cotton leaf worm and pink bollworm.

OBJECTIVES

•  Isolation of toxin genes from subspecies of Bt collected from different Egyptian habitats.

•  Sequencing the genes to determine the exact nucleotide sequences of both their regulatory and structural regions.

•  Expanding the insect host range of various Egyptian Bt isolates and strains.

•  Several unique Bt strains were discovered from Egyptian sources.

•  An Egyptian patent (no. 019797) was issued for the unique strain B. thuringiensis subsp. aegypti (C-18).

•  A patent (no. 60/03536) about B. thuringiensis subsp. aegypti (C-18) was obtained by the USA patent office  on January 10, 1997.

•  A new gene from strain C-18 was recognized by the International Nomenclature Committee and given the name Cry1IC1.

•  Production of AGERIN, a commercial biopesticide.

•  Several Cry toxin genes were cloned, sequenced and ready for introduction into plants.