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It produces a crystalline protein body pathogenic for the larvae of Lepidoptera.
It is used as a biological insecticide.











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crystalline body / parabasale crystals



photo wikipedia

Bacillus thuringiensis

  • General information

    • the following information is not yet verified
      Genetic evidence supports the recognition of members of the Bacillus cereus group as one species, but practical considerations (virulence characters) argue against such a move.

      Bacillus thuringiensis is distinguished by its characteristic parasporal crystals

      Taxonomy
      Family: Bacillaceae
      Bacillus cereus group: B.anthracis, B.cereus, B.mycoides, B.thuringiensis

      Natural habitats
      Endospores are widespread in soil and many other environments.
      The organism had been isolated from all continents, including Antartica.

      Used as bio pesticide

      Clinical significance
      It is an opportunistic pathogen for humans.
      Some strains may produce the B.cereus diarrheal toxin.

  • Gram stain

    • the following information is not yet verified
      Large Gram positive (variable) rods,

      1.1-1.2 x 3.0-6.0 µm
      (only B.cereus + B.megaterium group >1 µm)

      The bacilli tend to occur in chains

      Spore shape: ellipsoidal
      Spore position: central, paracentral or subterminal
      Sporangium swollen: negative

      Spores may lie obliquely in the sporangia

      Parasporal bodies within the sporangia.
      These crystalline protein inclusions may be bipyramidal, cuboid, spherical to ovoid, flat rectangular or heteromorphic in shape.

      They are formed outside the exosporium and readily separate from the liberated spore.

      They are known as delta-endotoxins or insecticidal crystal proteins.

      The bacilli tend to occur in chains

      Capsule not present

  • Culture characteristics

    • the following information is not yet verified

      Facultative anaerobic

      They are usually whitish to cream in color, large 2-7 mm, and vary in shape from circular to irregular with entire to undulate, crenate or fimbriate edges and they usually have matt or granular textures.

      Sometimes smooth and moist colonies may appear.

      Hemolytic

      BBAØ growth

  • Characteristics

  • References

    • James Versalovic et al.(2011) Manual of Clinical Microbiology 10th Edition


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