Adsorption and desorption of monomeric Bt (Bacillus thuringiensis) Cry1Aa toxin on montmorillonite and kaolinite

Helassa, Nordine; Quiquampoix, Hervé; Noinville, Sylvie; Szponarski, Wojciech; Staunton, Siobhán

doi:10.1016/j.soilbio.2008.12.008

Cited by 58 publications

(74 citation statements)

References 45 publications

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“…We have investigated the conformational changes of the Cry1Aa toxin upon adsorption onto montmorillonite. Previous studies have shown that Bt toxins adsorb better onto montmorillonite than onto other model minerals [5,28]. Montmorillonite has an electronegative surface independent of pH as a result of isomorphic substitution occurring mainly in the alumina octahedral sheet, which provides a valuable model surface for pH-dependent adsorption of proteins.…”

Section: Introductionmentioning

confidence: 99%

Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin

Helassa¹,

Revault²,

Quiquampoix³

et al. 2011

Journal of Colloid and Interface Science

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Section: Introductionmentioning

confidence: 99%

Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin

Helassa¹,

Revault²,

Quiquampoix³

et al. 2011

Journal of Colloid and Interface Science

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“…israelensis in the field (4,13). Contrary to other B. thuringiensis subspecies, for which toxins are studied mainly in the context of genetically modified crops, which produce large amounts of a unique soluble Cry toxin (20,29,40), B. thuringiensis subsp. israelensis is sprayed as a suspension of spores and crystals.…”

mentioning

confidence: 99%

Fate of Bacillus thuringiensis subsp. israelensis in the Field: Evidence for Spore Recycling and Differential Persistence of Toxins in Leaf Litter

Tetreau

Alessi

Veyrenc

et al. 2012

Appl Environ Microbiol

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Bacillus thuringiensis subsp. israelensis is a bioinsecticide increasingly used worldwide for mosquito control. Despite its apparent low level of persistence in the field due to the rapid loss of its insecticidal activity, an increasing number of studies suggested that the recycling of B. thuringiensis subsp. israelensis can occur under specific, unknown conditions. Decaying leaf litters sampled in mosquito breeding sites in the French Rhône-Alpes region several months after a treatment were shown to exhibit a high level of larval toxicity and contained large amounts of spores. In the present article, we show that the high concentration of toxins found in these litters is consistent with spore recycling in the field, which gave rise to the production of new crystal toxins. Furthermore, in these toxic leaf litter samples, Cry4Aa and Cry4Ba toxins became the major toxins instead of Cyt1Aa in the commercial mixture. In a microcosm experiment performed in the laboratory, we also demonstrated that the toxins, when added in their crystal form to nontoxic leaf litter, exhibited patterns of differential persistence consistent with the proportions of toxins observed in the field-collected toxic leaf litter samples (Cry4 > Cry11 > Cyt). These results give strong evidence that B. thuringiensis subsp. israelensis recycled in specific breeding sites containing leaf litters, and one would be justified in asking whether mosquitoes can become resistant when exposed to field-persistent B. thuringiensis subsp. israelensis for several generations.

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“…A different feeding strategy was successfully used for the bioassay of A. guerreronis, in which the dried solid fermented powder directly brushed on the infested coconut buttons [7,21]. Many authors used surfactants like BIT (1,2-benzisothiazolin-3-one), one of the inertingredients in Foray 48 B(a Btk formulation); the siloxane (organosilicone) Triton-X-100, Tween 20 and Latron CS-7 are some surfactants for Btk formulations [93].…”

Section: Bioassaymentioning

confidence: 99%

An Overview on the Crystal Toxins from <i>Bacillus thuringiensis</i>

Jisha¹,

Smitha²,

Benjamin³

2013

AiM

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Strains of Bacillus thuringiensis (Bt) are known to produce crystalline proteins (δ-endotoxins) concomitantly with sporulation during their stationary phase of growth, which are demonstrated as lethal to lepidopeterous, coleopeterous and dipterous insects in addition to mites, nematodes, protozoa and flukes. Upon ingestion, the δ-nascent endotoxin is an inactive protoxin complex of (Cry alone or Cry and Cyt toxins together) high molecular mass, which is cleaved upon ingestion into the active component proteins at the high alkaline environments in the digestive tract of these agricultural pests. Conventionally, Bt-crystals are being produced employing submerged or liquid fermentation techniques in commercial media, but recently many workers have used solid-state fermentation strategy for the enhanced production of Bt-toxin at low cost. Apart from δ-endotoxin, some isolates of Bt produce another class of insecticidal small molecules called β-exotoxin (thuringiensin), which may be harmful to humans. Moreover, resistance to Bt developed in various target pest is yet another concern for Bt-industry. Following a brief introduction, this review addresses various toxins produced by various strains of Bt, Bt production media and media formulations with emphasis to solid-state fermentation, general structure of Cry toxin, its mode of action, target pests, bioassay, resistance to Bt toxins and resistance management. Briefly, this review would provide the readers an overview on the general aspects of Bt toxin, its general structure and mechanism of action.

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Adsorption and desorption of monomeric Bt (Bacillus thuringiensis) Cry1Aa toxin on montmorillonite and kaolinite

Cited by 58 publications

References 45 publications

Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin

Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin

Fate of Bacillus thuringiensis subsp. israelensis in the Field: Evidence for Spore Recycling and Differential Persistence of Toxins in Leaf Litter

An Overview on the Crystal Toxins from <i>Bacillus thuringiensis</i>

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Adsorption and desorption of monomeric Bt (Bacillus thuringiensis) Cry1Aa toxin on montmorillonite and kaolinite

Cited by 58 publications

References 45 publications

Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin

Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin

Fate of Bacillus thuringiensis subsp. israelensis in the Field: Evidence for Spore Recycling and Differential Persistence of Toxins in Leaf Litter

An Overview on the Crystal Toxins from &lt;i&gt;Bacillus thuringiensis&lt;/i&gt;

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Product

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An Overview on the Crystal Toxins from <i>Bacillus thuringiensis</i>