Separation of three biologically distinct activities from the parasporal crystal ofBacillus thuringiensis var.israelensis

1985 ◽  
Vol 12 (3) ◽  
pp. 121-126 ◽  
Author(s):  
Peter Y. K. Cheung ◽  
Bruce D. Hammock
Keyword(s):  
Parasporal Crystal ◽  
Ofbacillus Thuringiensis

scholarly journals Parasporal Body Formation via Overexpression of the Cry10Aa Toxin of Bacillus thuringiensis subsp. israelensis, and Cry10Aa-Cyt1Aa Synergism

2009 ◽  
Vol 75 (14) ◽  
pp. 4661-4667 ◽  
Author(s):  
Alejandro Hernández-Soto ◽  
M. Cristina Del Rincón-Castro ◽  
Ana M. Espinoza ◽  
Jorge E. Ibarra
Keyword(s):  
Bacillus Thuringiensis ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Microbial Control ◽  
Control Agent ◽  
Mass Spectrometry Analysis ◽  
Parasporal Crystal ◽  
Spectrometry Analysis ◽  
Crystal Complex

ABSTRACT Bacillus thuringiensis subsp. israelensis is the most widely used microbial control agent against mosquitoes and blackflies. Its insecticidal success is based on an arsenal of toxins, such as Cry4A, Cry4B, Cry11A, and Cyt1A, harbored in the parasporal crystal of the bacterium. A fifth toxin, Cry10Aa, is synthesized at very low levels; previous attempts to clone and express Cry10Aa were limited, and no parasporal body was formed. By using a new strategy, the whole Cry10A operon was cloned in the pSTAB vector, where both open reading frames ORF1 and ORF2 (and the gap between the two) were located, under the control of the cyt1A operon and the STAB-SD stabilizer sequence characteristic of this vector. Once the acrystalliferous mutant 4Q7 of B. thuringiensis subsp. israelensis was transformed with this construct, parasporal bodies were observed by phase-contrast microscopy and transmission electron microscopy. Discrete, ca. 0.9-μm amorphous parasporal bodies were observed in the mature sporangia, which were readily purified by gradient centrifugation once autolysis had occurred. Pure parasporal bodies showed two major bands of ca. 68 and 56 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. These bands were further characterized by N-terminal sequencing of tryptic fragments using matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, which identified both bands as the products of ORF1 and ORF2, respectively. Bioassays against fourth-instar larvae of Aedes aegypti of spore-crystal complex and pure crystals of Cry10Aa gave estimated 50% lethal concentrations of 2,061 ng/ml and 239 ng/ml, respectively. Additionally, synergism was clearly detected between Cry10A and Cyt1A, as the synergistic levels (potentiation rates) were estimated at 13.3 for the mixture of Cyt1A crystals and Cry10Aa spore-crystal complex and 12.6 for the combination of Cyt1A and Cry10Aa pure crystals.

scholarly journals A technique for the effective enrichment and isolation ofBacillus thuringiensis

1996 ◽  
Vol 142 (2-3) ◽  
pp. 173-177 ◽  
Author(s):  
Clare Johnson ◽  
Alistair H. Bishop
Keyword(s):  
Ofbacillus Thuringiensis

Ultra-violet-resistant mutants ofBacillus thuringiensis

1991 ◽  
Vol 70 (6) ◽  
pp. 460-463 ◽  
Author(s):  
D.R. Jones ◽  
V. Karunakaran ◽  
H.D. Burges ◽  
A.J. Hacking
Keyword(s):  
Ultra Violet ◽  
Ofbacillus Thuringiensis ◽  
Resistant Mutants

Screening for highly effective isolates ofBacillus thuringiensis againstSpodoptera exempta andSpodoptera littoralis

1991 ◽  
Vol 19 (1) ◽  
pp. 9-21 ◽  
Author(s):  
M. Hamal ◽  
M. Brownbridge ◽  
M. Broza ◽  
B. Sneh
Keyword(s):  
Ofbacillus Thuringiensis ◽  
Highly Effective
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