The lepidopteran-specific P1 delta-endotoxin of Bacillus thuringiensis var. kurstaki HD-1 was activated in vitro using insect gut proteases and found to be highly specific for the lepidopteran cell line Choristoneura fumiferana CF1 among a wide range of lepidopteran and dipteran cell lines tested. The toxicity of P1 against CF1 cells is inhibited by N-acetylgalactosamine (GalNAc), and the lecti...

It was found by using spectrophotometric, spectrofluorometric, and high-pressure liquid chromatography that four subspecies of Bacillus thuringiensis produce coproporphyrin. The porphyrin isomer was identified as coproporphyrin I for B. thuringiensis subsp. kurstaki (HD1). The porphyrin was isolated both from spores and from a variety of spent growth media. The quantity of porphyrin released by...

some wastes especially wastes of food industries need to be treated in order to recover some value-added products. one of these valuable products is biological pesticides. today, the most successful biological pesticides are produced by gram-positive, rod-shape bacteria, the genus bacillus that produces crystalline endotoxin proteins during spore formation. these toxins will be activated when t...

leaf-colonizing strain of Bacillus cereus. and Bacillus thuringiensis and in a subsp. kurstaki expressed in Escherichia coli the NRD-12 isolate of Bacillus thuringiensis Insecticidal activity of the CryIIA protein from

Bioinsecticide Bacillus thuringiensis var. kurstaki (Btk) was used for controlling the mosquito species (Anopheles stephensi and Culex quinquefasciatus) which gave a significant (p<0.05) mortality in both species. The higher concentration of Btk was highly effective compared to the control ones. The controlling effect was dose and time dependent. Among the studied mosquitoes the C. quinquefasci...

A low frequency of chromosomal gene transfer from Bacillus thuringiensis to Bacillus cereus was detected by cell mating, with a tryptophan marker being the most frequently transferred gene among four that were tested. The process was resistant to DNase and was not mediated by cell filtrates. Among several B. thuringiensis subspecies tested, transfer was best with a derivative of B. thuringiensi...

Bacillus spore surface morphology was imaged with atomic force microscopy (AFM) to determine if characteristic surface features could be used to distinguish between four closely related species; Bacillus anthracis Sterne strain, Bacillus thuringiensis var. kurstaki, Bacillus cereus strain 569, and Bacillus globigii var. niger. AFM surface height images showed an irregular topography across the ...

we investigated the effects of interaction between cotesia plutellae (kurdjumov) and bacillus thuringiensis berliner on parasitism and an immune effector (phenoloxidase activity) of a bt-susceptible and a bt-resistant population of plutella xylostella (linnaeus) in laboratory. parasitism success of c. plutellae varied depending on the use of b. thuringiensis or its toxin, and the timing of appl...