NC_008598:21978 Bacillus thuringiensis str. Al Hakam plasmid pALH1, complete
Host Lineage: Bacillus thuringiensis; Bacillus; Bacillaceae; Bacillales; Firmicutes; Bacteria
General Information: Produces insect toxin. This organism, also known as BT, is famous for the production of an insecticidal toxin. The bacterium was initially discovered as a pathogen of various insects and was first used as an insecticidal agent in the early part of this century. This organism, like many other Bacilli, is found in the soil, where it leads a saprophytic existence, but becomes an opportunistic pathogen of insects when ingested. The specific activity of the toxin towards insects and its lack of toxicity to animals has made this organism a useful biocontrol agent. The delta-endotoxin, which is produced during the sporulation part of the life cycle, causes midgut paralysis and disruption of feeding by the infected insect host. The delta-endotoxin, which is produced during the sporulation part of the life cycle, causes midgut paralysis and disruption of feeding by the infected insect host. The delta-endotoxin, which is produced during the sporulation part of the life cycle, causes midgut paralysis and disruption of feeding by the infected insect host. The presence of a parasporal crystal, which is outside the exosporium of the endospore, is indicative of production of the toxin, and serves as a marker for this species.Activation of the toxin typically requires a high pH environment such as the alkaline environments in insect midguts followed by proteolysis. Various toxin genes specific for a variety of insects have been studied, and many are now being used in genetically modified plants which have been engineered to produce the toxin themselves, eliminating the need to produce sufficient amounts of B. thuringiensis spores.