morphological and electrophoretic analysis of the crystalline inclusions (parasporal crystals) of sporulated cultures of b. thuringiensis ssp. kumamotoensis dsm 6070 (bt 6070) was conducted via phase contrast and scanning electron microscopy and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. the activity of the spore-crystal suspensions against house fly (musca domestica) larvae wa...

Bacillus thuringiensis was isolated from 36 of 50 residue samples obtained from an animal feed mill (a stored-product environment). Of 710 selected colonies having Bacillus cereus-B. thuringiensis morphology isolated from the samples, 477 were classified as B. thuringiensis because of production of parasporal delta-endotoxin crystals. There was a diverse population of B. thuringiensis, as revea...

In the course of sporulation, some strains of Bacillus sphaericus synthesize a parasporal inclusion or "crystal" (Fig. 1), which contains proteins toxic for larvae of a variety of mosquito species (64, 74). Upon completion of sporulation, the crystal remains associated with the endospore, both being enclosed within the exosporium (74). The major components of the crystal are two proteins of 51 ...

Bacillus pumilus strain 15.1 was previously found to cause larval mortality in the Med-fly Ceratitis capitata and was shown to produce crystals in association with the spore. As parasporal crystals are well-known as invertebrate-active toxins in entomopathogenic bacteria such as Bacillus thuringiensis (Cry and Cyt toxins) and Lysinibacillus sphaericus (Bin and Cry toxins), the B. pumilus crysta...

Cyt1A protein is a cytolytic protein encoded by the cyt gene of Bacillus thuringiensis subsp. israelensis (Bti) as part of the parasporal crystal proteins produced during the sporulation. Cyt1A protein is unique compared to the other endotoxins present in these parasporal crystals. Unlike δ-endotoxins, Cyt1A protein does not require receptors to bind to the target cell and activate the toxicity...

Four genes encoding parasporins, cytotoxins preferentially killing human cancer cells in vitro, were isolated from four Vietnamese strains of Bacillus thuringiensis. Nucleotide sequence analysis revealed that: (1) three genes fall into the two known classes, ps1Aa and ps1Ab, and (2) another one belongs to ps1Ac, a novel gene class established in this study. Upon proteolytic activation, paraspor...

During sporulation of Bacillus thuringiensiS, a spore and a protein parasporal inclusion are formed within each cell (Hannay & Fitz-James, 1955; Hannay, 1956). The parasporal inclusions are of a regular, dipyramidal form and are referred to as 'crystals'. Similar 'crystals' are formed by a number of related strains of Bacillus, all of which are pathogenic to insect larvae. The crystals are comp...