Bacillus thuringiensis

Title: Bacillus thuringiensis
Additional Names: Bt
Trademarks: Sporeine
Literature References: A gram-positive spore-forming bacterium which during sporulation forms a parasporal protein crystal with insecticidal properties. Various subspecies are used as bioinsecticides against Lepidoptera, Diptera, and Coleoptera pests. First isolated by Ishiwata in 1902 from dying silkworm larvae. Later isolated as B. thuringiensis, Berliner, from the larvae of the flour moth, Ephestia kuehniella Zell: Berliner, Z. Angew. Entomol. 2, 29 (1915). Characterization of the protein crystal: K. W. Nickerson, Biotechnol. Bioeng. 22, 1305 (1950); C. L. Hannay, Nature 172, 1004 (1953). The protein crystals consist of one or more types of protoxin subunits known as d-endotoxins. Bt also produces an exotoxin which is released in the culture medium during bacterial growth. Isoln and structure of the exotoxin: Sebesta et al., Collect. Czech. Chem. Commun. 34, 891 (1969); Farkas et al., ibid. 1118. Review of ultrastructure, physiology and biochemistry: L. A. Bulla et al., Crit. Rev. Microbiol. 8, 147-204 (1980); of industrial production: X.-M. Yang, S. S. Wang, Biotechnol. Appl. Biochem. 28, 95-98 (1998). Review of persistence in soil and effects on non-target organisms: J. A. Addison, Can. J. For. Res. 23, 2329-2342 (1993); of mammalian safety and toxicity studies: J. T. McClintock et al., Pestic. Sci. 45, 95-105 (1995). Review of expression of toxin genes in plant cells: M. Mazier et al. in Biotechnology Annual Review vol. 3, M. R. El-Gewely, Ed. (Elsevier Science, Amsterdam, 1997) pp 313-347; of use in transgenic plants for insect resistance: L. Jouanin et al., Plant Sci. 131, 1-11 (1998).
Derivative Type: Bacillus thuringiensis subsp. israelensis
Trademarks: Skeetal (Valent); Teknar (Certis)
Derivative Type: Bacillus thuringiensis subsp. kurstaki
Trademarks: Deliver (Certis); DiPel (Valent); Javelin (Certis); Thuricide (Certis)
Use: Bioinsecticide.
Bacilysin Bacimethrin Bacitracin Bacitracin Methylenedisalicylate Bacitracin Zinc

Bacillus thuringiensis
Spores and bipyramidal crystals of Bacillus thuringiensis morrisoni strain T08025
Scientific classification
Domain: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Bacillaceae
Genus: Bacillus
Species: B. thuringiensis
Binomial name
Bacillus thuringiensis
Berliner 1915
Gram stain of Bacillus thuringiensis under 1000 X magnification

Bacillus thuringiensis (or Bt) is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide. B. thuringiensis also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic environments, animal feces, insect rich environments, flour mills and grain storage facilities.[1][2]

During sporulation, many Bt strains produce crystal proteins (proteinaceous inclusions), called δ-endotoxins, that have Insecticide action. This has led to their use as insecticides, and more recently to genetically modified crops using Bt genes. Many crystal-producing Bt strains, though, do not have insecticidal properties.[3]