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cloning, characterization, and expression of a new cry1ab gene from dor bt-1, an indigenous isolate of bacillus thuringiensis.a new cry1ab gene was cloned from the promising local isolate, dor bt-1, a bacillus thuringiensis strain isolated from castor semilooper (achaea janata l.) cadavers from castor bean (ricinus communis l.) field. the nucleotide sequence of the cloned cry1ab gene indicated that the open reading frame consisted of 3,465 bases encoding a protein of 1,155 amino acid residues with an estimated molecular weight of 130 kda. homology comparisons revealed that the deduced amino acid sequence of cry1ab had ...201323224937
bacillus thuringiensis cry1ia10 and vip3aa protein interactions and their toxicity in spodoptera spp. (lepidoptera).the polyphagous pests belonging to the genus spodoptera are considered to be among the most important causes of damage and are widely distributed throughout the americas'. due to the extensive use of genetically modified plants containing bacillus thuringiensis genes that code for insecticidal proteins, resistant insects may arise. to prevent the development of resistance, pyramided plants, which express multiple insecticidal proteins that act through distinct mode of actions, can be used. this ...201323220241
histopathological effects and determination of the putative receptor of bacillus thuringiensis cry1da toxin in spodoptera littoralis midgut.bacillus thuringiensis subsp. aizawai strain hd133, known by its effectiveness against spodoptera species, produces many insecticidal proteins including cry1ab, cry1ca and cry1da. in the present study, the insecticidal activity of cry1da against spodoptera littoralis was investigated. it showed toxicity with an lc(50) of 224.4 ng/cm(2) with 95% confidence limits of (178.61-270.19) and an lc(90) of 467.77 ng/cm(2) with 95% confidence limits of (392.89-542.65). the midgut histopathology of cry1da ...201323220238
parasporin 1ac2, a novel cytotoxic crystal protein isolated from bacillus thuringiensis b0462 strain.two novel parasporin (ps) genes were cloned from bacillus thuringiensis b0462 strain. one was 100 % identical even in nucleotide sequence level with that of parasporin-1aa (ps1aa1) from b. thuringiensis a1190 strain. the other (ps1ac2) showed significant homology (99 % identity) to that of ps1ac1 from b. thuringiensis 87-29 strain. the 15 kda (s(113)-r(250)) and 60 kda (i(251)-s(777)) fragments consisting of an active form of ps1ac2 were expressed as his-tag fusion. upon purification under denat ...201323306354
sex differences in host defence interfere with parasite-mediated selection for outcrossing during host-parasite coevolution.the red queen hypothesis proposes that coevolving parasites select for outcrossing in the host. outcrossing relies on males, which often show lower immune investment due to, for example, sexual selection. here, we demonstrate that such sex differences in immunity interfere with parasite-mediated selection for outcrossing. two independent coevolution experiments with caenorhabditis elegans and its microparasite bacillus thuringiensis produced decreased yet stable frequencies of outcrossing male h ...201323301667
ochratoxin a management in vineyards by lobesia botrana biocontrol.grape berries attacked by lobesia botrana larvae are more easily infected by aspergillus section nigri (black aspergilli) ochratoxigenic species. two-year field trials were carried out in apulia (italy) to evaluate a bioinsecticide control strategy against l. botrana and the indirect effect on reducing ochratoxin a (ota) contamination in vineyards. a commercial bacillus thuringiensis formulate and an experimental beauveria bassiana (item-1559) formulate were tested in two vineyards cultivated wi ...201323282670
affinity maturation of cry1aa toxin to the bombyx mori cadherin-like receptor by directed evolution.improvement of the activity and insecticidal spectrum of cloned cry toxins of bacillus thuringiensis should allow for their wider application as biopesticides and a gene source for gene-modified crops. the insecticidal activity of cry toxins depends on their binding to the receptor. therefore, as a model, we aimed to generate improved binding affinity mutant toxins against bombyx mori cadherin-like receptor (btr175) using methods of directed evolution with the expectation of insecticidal activit ...201323247992
bacillus thuringiensis isolates from great nicobar islands.bacillus thuringiensis (bt) strains were isolated from soil samples of great nicobar islands, one of the "hottest biodiversity hotspots," where no collection has been characterized previously. the 36 new bt isolates were obtained from 153 samples analyzed by crystal protein production with light/phase-contrast microscopy, determination of cry gene profile by sds-page, evaluation of toxicity against coleopteran, and lepidopteran insect pests, finally cloning and sequencing. majority of the isolat ...201323377491
overexpression of polyphosphate kinase gene (ppk) increases bioinsecticide production by bacillus thuringiensis.polyphosphate (polyp), synthesized by polyp kinase (ppk) using the terminal phosphate of atp as substrate, performs important functions in every living cell. the present work reports on the relationship between polyp metabolism and bioinsecticide production in bacillus thuringiensis subsp. israelensis (bti). the ppk gene of bti was cloned into vector pht315 and the effect of its overexpression on endotoxin production was determined. endotoxin production by the recombinant strain was found to be ...201323369305
influence of oxalic and malic acids in chickpea leaf exudates on the biological activity of cryiac towards helicoverpa armigera.efforts are being made to express toxin genes from the bacterium, bacillus thuringiensis (bt) in chickpea for minimizing the losses due to the pod borer, helicoverpa armigera. however, there is an apprehension that acidic exudates in chickpea leaves may influence the protoxin-toxin conversion in the insect midgut, and thus, reduce the efficacy of bt toxins. therefore, we studied the influence of organic acids (oxalic acid and malic acid) present in the trichome exudates of chickpea on the biolog ...201323391855
long-term survival of bacillus thuringiensis subsp. kurstaki in a field trial.long-term survival of bacillus thuringiensis subsp. kurstaki dmu67r has been investigated in a field trial. an experimental cabbage plot was sprayed with dmu67r in 1993 and was allowed to lie fallow since then. the investigation reported here was carried out from 2001 to 2007 in a single square meter within the plot using a systematic randomized sampling approach. the bacterium survived at relative low densities in these 13 years after spraying. statistical analyses revealed that the overall den ...201323391227
effect of vegetation on the presence and genetic diversity of bacillus thuringiensis in soil.bacillus thuringiensis isolates were obtained from soil samples collected at different sites located in the same region but with different vegetation. the sites showed different frequencies of b. thuringiensis, depending on the type of vegetation. strains of b. thuringiensis were found to be less common in samples of riparian forest soil than in soil of other types of vegetation. the rate of occurrence of b. thuringiensis in the samples also varied according to the vegetation. these results show ...201323391226
a phenylalanine clamp controls substrate specificity in the quorum-quenching metallo-γ-lactonase from bacillus thuringiensis.autoinducer inactivator a (aiia) is a metal-dependent n-acyl homoserine lactone hydrolase that displays broad substrate specificity but shows a preference for substrates with long n-acyl substitutions. previously, crystal structures of aiia in complex with the ring-opened product n-hexanoyl-l-homoserine revealed binding interactions near the metal center but did not identify a binding pocket for the n-acyl chains of longer substrates. here we report the crystal structure of an aiia mutant, f107w ...201323387521
impact of six transgenic bacillus thuringiensis rice lines on four nontarget thrips species attacking rice panicles in the paddy field.as a key component of ecological risk assessments, nontarget effects of bacillus thuringiensis (bt) rice have been tested under laboratory and field conditions for various organisms. a 2-yr field experiment was conducted to observe the nontarget effects of six transgenic rice lines (expressing the cry1ab or fused protein of cry1ab and cry1ac) on four nontarget thrips species including frankliniella intonsa (trybom), f. tenuicornis (uzel), haplothrips aculeatus (f.), and h. tritici (kurd), as com ...201323339799
application of box-behnken experimental design to optimize the extraction of insecticidal cry1ac from soil.a validated method for analyzing cry proteins is a premise to study the fate and ecological effects of contaminants associated with genetically engineered bacillus thuringiensis crops. the current study has optimized the extraction method to analyze cry1ac protein in soil using a response surface methodology with a three-level-three-factor box-behnken experimental design (bbd). the optimum extraction conditions were at 21 °c and 630 rpm for 2 h. regression analysis showed a good fit of the exper ...201323327690
laboratory assessment of the impacts of transgenic bt rice on the ecological fitness of the soil non-target arthropod, folsomia candida (collembola: isotomidae).transgenic rice expressing bacillus thuringiensis (bt) endotoxins (bt rice) for pest control is considered an important solution to food security in china. however, tests for potential effects on non-target soil organisms are required for environmental risk assessment. the soil collembolan folsomia candida l. (collembola: isotomidae) is a potential non-target arthropod that is often used as a biological indicator in bio-safety assessments of transgenic crops. in the present study, the roots, ste ...201323322316
electrogenerated chemiluminescence immunosensor for bacillus thuringiensis cry1ac based on fe3o4@au nanoparticles.a highly sensitive electrochemiluminescence (ecl) immunosensor for cry1ac was fabricated. the primary antibody anti-cry1ac was immobilized onto core-shell structural fe(3)o(4)@au nanoparticles. the antigen and glucose-oxidase-labeled secondary antibody were then successively combined to form sandwich-type immunocomplexes through a specific interaction. the magnetic particles loaded with sandwich immune complexes were attracted to a magnet-controlled glass carbon electrode (gce) by an external ma ...201323317307
cyt1aa from bacillus thuringiensis subsp. israelensis enhances mosquitocidal activity of b. thuringiensis subsp. kurstaki hd-1 against aedes aegypti but not culex quinquefasciatus.the cyt1aa protein of bacillus thuringiensis subsp. israelensis is known to synergize mosquitocidal proteins of b. thuringiensis and bacillus sphaericus strains. cyt1aa is highly lipophilic, and after binding in vivo to the midgut microvillar membrane serves as a "receptor" for mosquitocidal cry proteins, which subsequently form cation channels that kill mosquito larvae. here we report that cyt1aa can serve a similar function for lepidopteran-specific cry proteins of b. thuringiensis in certain ...201323314373
health effects of selected microbiological control agents. a 3-year follow-up study.microbiological control agents (mbca) are widely used in greenhouses, replacing chemical pesticides. the presented study aims to describe health effects of exposure to three types commonly used: bacillus thuringiensis, verticillium lecanii, and trichoderma harzenianum covering seven different products in greenhouse workers with emphasis on sensitization and respiratory effects.201223311779
[comparison of codon optimizations of cry1ah1 gene in rice].cry1ah1, one of holo-type cry genes, cloned in this laboratory from bacillus thuringiensis strain has been patented in china, and it encoded a protein with strong insecticidal activity against certain lepidopteran insect pests, such as chilo suppressalis. cry1ah1 gene is exhibiting good application prospects. in order to improve the expression level of cry1ah1 gene in rice, and investigate the effect of codon usage preference of gene expression, we designed five different optimized schemes for c ...201223311133
new variants of lepidoptericidal toxin genes encoding bacillus thuringiensis vip3aa proteins.bacillus thuringiensis is an entomopathogenic bacterium characterized by producing parasporal proteinaceous insecticidal crystal inclusions during sporulation. many strains are capable of also expressing other insecticidal proteins called vip during the vegetative growing phase. particularly, vip3a proteins have activity against certain lepidoptera species through a unique mechanism of action which emphasized their possible use in resistance management strategies against resistant pests. the aim ...201223307196
susceptibility and selectivity of cnaphalocrocis medinalis (lepidoptera: pyralidae) to different cry toxins.effectiveness of four cry toxins (cry1ac, cry1aa, cry1ab, and cry1c) on cnaphalocrocis medinalis (guenée) (lepidoptera: pyralidae), collected from paddy fields in jiaxing, zhejiang province, china, was evaluated in the laboratory. bioassays showed that c. medinalis had different susceptibilities against four cry toxins. the lc50 values of cry1ac, cry1ab, cry1aa, and cry1c against c. medinalis were 0.405, 1.111, 1.939, and 1.246 microg/ml, respectively. furthermore, the mortality of c. medinalis ...201223356078
mortality and repellent effects of microbial pathogens on coptotermes formosanus (isoptera: rhinotermitidae).two entomopathogenic fungi, isaria fumosorosea and metarhizium anisopliae, and one bacterium, bacillus thuringiensis, were tested for their ability to cause mortality of formosan subterranean termites (fst), coptotermes formosanus (shiraki), after liquid exposure, and for their lack of propensity to repel fst.201223241169
[activity of four cry gene promoters in spoiiid mutant of bacillus thuringiensis].we studied the influence of spoiiid gene deletion on the activity of cry1ac, cry3a, cry4a and cry8e gene promoters in bacillus thuringiensis and compared the activity among these promoters in spoiiid mutant (hd-delta spoiiid).201223236841
effects of cry1ab transgenic maize on lifecycle and biomarker responses of the earthworm, eisenia andrei.a 28-day study was conducted to determine the effects of the bacillus thuringiensis cry1ab toxin on the earthworm eisenia andrei. previously, investigations have been limited to life-cycle level effects of this protein on earthworms, and mostly on e. fetida. in this study several endpoints were compared which included biomass changes, cocoon production, hatching success, a cellular metal-stress biomarker (neutral red retention time; nrrt) and potential genotoxic effects in terms of randomly ampl ...201223235452
non-recessive bt toxin resistance conferred by an intracellular cadherin mutation in field-selected populations of cotton bollworm.transgenic crops producing bacillus thuringiensis (bt) toxins have been planted widely to control insect pests, yet evolution of resistance by the pests can reduce the benefits of this approach. recessive mutations in the extracellular domain of toxin-binding cadherin proteins that confer resistance to bt toxin cry1ac by disrupting toxin binding have been reported previously in three major lepidopteran pests, including the cotton bollworm, helicoverpa armigera. here we report a novel allele from ...201223285292
greenhouse-selected resistance to cry3bb1-producing corn in three western corn rootworm populations.transgenic corn producing the bacillus thuringiensis (bt) toxin cry3bb1 has been useful for controlling western corn rootworm, diabrotica virgifera virgifera leconte, one of the most economically important crop pests in the united states. however, rapid evolution of resistance by this beetle to bt corn producing cry3bb1 has been reported previously from the laboratory, greenhouse, and field. here we selected in the greenhouse for resistance to cry3bb1 corn in three colonies of wcr derived from k ...201223284656
complete genome sequence of bacillus thuringiensis serovar sichuansis strain mc28.bacillus thuringiensis is an important microbial insecticide used in the control of agricultural pests. here we report the finished, annotated genome sequence of bacillus thuringiensis serovar sichuansis strain mc28, which can form parasporal crystals consisting of cry4cc1, cry30fa1, cry53ab1, cry54aa1, cry54ab1, cry68aa1, cry69aa1, cry69aa2, cry70ba1, cyt1da1, and cyt2aa3. it is also highly toxic to lepidopterous and dipterous insects.201223209229
lengthening of insect development on bt zone results in adult emergence asynchrony: does it influence the effectiveness of the high dose/refuge zone strategy?the “high dose/refuge” strategy (hd/r) is the currently recommended insect resistance management strategy (irm) to limit resistance development to bacillus thuringiensis (bt) plants. this strategy requires planting a “refuge zone” composed of non-bt plants suitable for the target insect and in close proximity to a “bt zone” expressing a high toxin concentration. one of the main assumptions is that enough susceptible adults mate with resistant insects. however, ...201223202319
a differentially displayed mrna related to resistance to bacillus thuringiensis israelensis of aedes albopictus selected in vitro-activated cyt1aa6.we compared the differential display of aedes albopictus cells, both resistant and susceptible to bacillus thuringiensis israelensis (bti), using differentially displayed reverse transcription polymerase chain reaction. we found 1 band about 200 base pairs long. after cloning and sequencing, the differentially expressed gene was similar to some partial messenger ribonucleic acid of ae. aegypti, culex quinquefasciatus, and anopheles gambiae, rather than ae. albopictus. this will be of some value ...201223393759
system wide analysis of the evolution of innate immunity in the nematode model species caenorhabditis elegans and pristionchus pacificus.the evolution of genetic mechanisms used to combat bacterial infections is critical for the survival of animals and plants, yet how these genes evolved to produce a robust defense system is poorly understood. studies of the nematode caenorhabditis elegans have uncovered a plethora of genetic regulators and effectors responsible for surviving pathogens. however, comparative studies utilizing other free-living nematodes and therefore providing an insight into the evolution of innate immunity have ...201223028509
ph-controlled bacillus thuringiensis cry1ac protoxin loading and release from polyelectrolyte microcapsules.crystal proteins synthesized by bacillus thuringiensis (bt) have been used as biopesticides because of their toxicity to the insect larval hosts. to protect the proteins from environmental stress to extend their activity, we have developed a new microcapsule formulation. poly (acrylic acid) (pah) and poly (styrene sulfonate) (pss) were fabricated through layer-by-layer self-assembly based on a caco(3) core. cry1ac protoxins were loaded into microcapsules through layer-by-layer self-assembly at l ...201223024810
capillary electrophoretic profiling of tryptic digests of water soluble proteins from bacillus thuringiensis-transgenic and non-transgenic maize species.capillary zone electrophoresis (cze) has been applied to separation and characterisation of enzymatic (tryptic) hydrolysates of water-soluble proteins from bacillus thuringiensis (bt)-transgenic (aristis-bt) and two native non-transgenic (aristis and coventry) maize varieties. water-soluble proteins were extracted from the flour of these maize species and digested by bovine pancreatic trypsin immobilised on agarose gel in 100 mm ammonium hydrocarbonate buffer, ph 7.9. the yielded tryptic digests ...201225005989
detection and tracking of a novel genetically tagged biological simulant in the environment.a variant of bacillus thuringiensis subsp. kurstaki containing a single, stable copy of a uniquely amplifiable dna oligomer integrated into the genome for tracking the fate of biological agents in the environment was developed. the use of genetically tagged spores overcomes the ambiguity of discerning the test material from pre-existing environmental microflora or from previously released background material. in this study, we demonstrate the utility of the genetically "barcoded" simulant in a c ...201223001670
microbial ecology and association of bacillus thuringiensis in chicken feces originating from feed.to explain the association of bacillus thuringiensis (bt) with animal feces, an ecological analysis in chickens was conducted by introducing a cry(-) strain marked by production of green fluorescent protein (gfp). after feeding with the tagged bt strains, the feces of the tested chickens were collected at different times, isolated, and the morphology of bt was observed. it was shown that bt strain hd-73gfp in spore form could be isolated from feces of chickens for a period of 13 d, and then it d ...201222986821
spray application of bacillus thuringiensis israelensis (bti strain am65-52) against aedes aegypti (l.) and ae. albopictus skuse populations and impact on dengue transmission in a dengue endemic residential site in malaysia.a one year study was conducted to evaluate the impact of spray application of bacillus thuringiensis israelensis (bti), strain am65-52 on vector populations and dengue transmission in a dengue endemic state in malaysia. residential sites with similar populations of aedes aegypti (l.) and aedes albopictus skuse were studied. one site was treated with spray application of bti into all outdoor target vector habitats, which consisted of natural and artificial containers. the other site was not treat ...201223082582
synthesis of bioactive microcapsules using a microfluidic device.bioactive microcapsules containing bacillus thuringiensis (bt) spores were generated by a combination of a hydro gel, microfluidic device and chemical polymerization method. as a proof-of-principle, we used bt spores displaying enhanced green fluorescent protein (egfp) on the spore surface to spatially direct the egfp-presenting spores within microcapsules. bt spore-encapsulated microdroplets of uniform size and shape are prepared through a flow-focusing method in a microfluidic device and conve ...201223112592
homology modeling of mosquitocidal cry30ca2 of bacillus thuringiensis and its molecular docking with n-acetylgalactosamine.to investigate the theoretical model of the three-dimensional structure of mosquitocidal cry30ca2 and its molecular docking with n-acetylgalactosamine.201223122318
mortality of adult stomoxys calcitrans fed isolates of bacillus thuringiensis.we examined the ability of five isolates of bacillus thuringiensis berliner to cause mortality in adult stable flies, stomoxys calcitrans (l.). isolates bacillus thuringiensis tolworthi 4l3 (serotype 9), bacillus thuringiensis darmstadiensis 4m1 (serotype 10a10b), bacillus thuringiensis thompsoni 401 (serotype 12), bacillus thuringiensis thuringiensis hd2 (serotype 1), and bacillus thuringiensis kurstaki hd945 (serotype 3a3b3c) were administered to adult flies in diets containing blood only, sug ...201223156187
evaluation of corn hybrids expressing cry1f, cry1a.105, cry2ab2, cry34ab1/cry35ab1, and cry3bb1 against southern united states insect pests.studies were conducted across the southern united states to characterize the efficacy of multiple bacillus thuringiensis (bt) events in a field corn, zea mays l., hybrid for control of common lepidopteran and coleopteran pests. cry1f protein in event tc1507 and cry1a.105 + cry2ab2 proteins in event mon 89034 were evaluated against pests infesting corn on above-ground plant tissue including foliage, stalks, and ears. cry34ab1/cry35ab1 proteins in event das-59122-7 and cry3bb1 in event mon 88017 w ...201223156183
early season host plants of apolygus lucorum (heteroptera: miridae) in northern china.apolygus lucorum (meyer-dür) (heteroptera: miridae) has become a severe pest of cotton and many other crops in northern china as a result of the widespread adoption of bacillus thuringiensis (berliner) cotton, with a corresponding reduction of broad-spectrum insecticide application in cotton fields. from the middle of april to middle june, a. lucorum feeds and develops on other host plants before dispersing to cotton fields. effective suppression of a. lucorum populations before they enter cotto ...201223156156
effectiveness of the high dose/refuge strategy for managing pest resistance to bacillus thuringiensis (bt) plants expressing one or two toxins.to delay resistance development to bacillus thuringiensis (bt) plants expressing their own insecticide, the application of the insect resistance management strategy called "high dose/refuge strategy" (hd/r) is recommended by the us environmental protection agency (us epa). this strategy was developed for bt plants expressing one toxin. presently, however, new bt plants that simultaneously express two toxins are on the market. we used a mathematical model to evaluate the efficiency of the hd/r st ...201223162699
construction and characterisation of an antifungal recombinant bacillus thuringiensis with an expanded host spectrum.a novel antifungal bacillus thuringiensis strain 19-22, ssp. kurstaki (h3a3b3c), was characterised. this strain included cry1aa, cry1ab, cry1ac, and cry1d, which have high insecticidal activities against lepidopteran larvae other than spodoptera exigua. to expand the host spectrum, a cry1e gene whose product is active against s. exigua was introduced into the isolate. the transformant successfully expressed the cry1e protein without any loss of its original antifungal activities. these results i ...201223124760
cis-acting motifs in artificially synthesized expression cassette leads to enhanced transgene expression in tomato (solanum lycopersicum l.).efficacy of artificial synthetic expression modules was compared with native camv35s and decamv35s promoter in transgenic tomato developed by agrobacterium-mediated transformation. the promoters under trial were camv35s-mec (pcami), camv35s (pcamii), decamv35s (pcamiii), synthetic minimal expression cassette (pmec), complete expression cassette (pcec), double enhancer expression cassette (pdec) and triple enhancer expression cassette (ptec) for driving the uida gene for β-glucuronidase (gus) act ...201223137727
withdrawn: effects of oral administration of bacillus thuringiensis as spore-crystal strains cry1aa, cry1ab, cry1ac or cry2aa on hematologic and genotoxic endpoints of swiss albino mice.this article has been withdrawn at the request of the author(s) and/or editor. the publisher apologizes for any inconvenience this may cause. the full elsevier policy on article withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.201223146696
novel bacteriophages containing a genome of another bacteriophage within their genomes.a novel bacteriophage infecting staphylococus pasteuri was isolated during a screen for phages in antarctic soils. the phage named spaa1 is morphologically similar to phages of the family siphoviridae. the 42,784 bp genome of spaa1 is a linear, double-stranded dna molecule with 3' protruding cohesive ends. the spaa1 genome encompasses 63 predicted protein-coding genes which cluster within three regions of the genome, each of apparently different origin, in a mosaic pattern. in two of these regio ...201222815791
effects of entomopathogenic nematodes on evolution of pink bollworm resistance to bacillus thuringiensis toxin cry1ac.the evolution of resistance by pests can reduce the efficacy of transgenic crops that produce insecticidal toxins from bacillus thuringiensis (bt). however, fitness costs may act to delay pest resistance to bt toxins. meta-analysis of results from four previous studies revealed that the entomopathogenic nematode steinernema riobrave (rhabditida: steinernematidae) imposed a 20% fitness cost for larvae of pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), that were homo ...201222812141
effect of temperature on the fitness of a vip3a resistant population of heliothis virescens (lepidoptera: noctuidae).microbial insecticides derived from the soil bacterium bacillus thuringiensis (bt) have become increasingly important for pest management. in addition to crystal (cry) insecticidal protein toxins formed during sporulation, vegetative insecticidal protein (vip) toxins can be produced during the vegetative phase. resistance to cry toxins has been reported in laboratory- and field-selected populations of various lepidoptera species and several studies have identified fitness costs associated with c ...201222812137
delaying corn rootworm resistance to bt corn.transgenic crops producing bacillus thuringiensis (bt) toxins for insect control have been successful, but their efficacy is reduced when pests evolve resistance. to delay pest resistance to bt crops, the u.s. environmental protection agency (epa) has required refuges of host plants that do not produce bt toxins to promote survival of susceptible pests. such refuges are expected to be most effective if the bt plants deliver a dose of toxin high enough to kill nearly all hybrid progeny produced b ...201222812111
evaluation of rhizospheric pseudomonas and bacillus as biocontrol tool for xanthomonas campestris pv campestris.xanthomonas campestris pv campestris (xcc), causing black rot, is one of the most yield-limiting and destructive pathogens of cruciferous crops. the intention of this study was to evaluate the potential of rhizobacteria in black rot management. fifty-four isolates from rhizosphere soil of brassica campestris were screened against xcc. two isolates namely, ka19 and se, with inhibition radius >11 mm were selected. the combined use of them produced an average inhibition zone of 18.1 ± 1.4 mm radius ...201222806865
preliminary comparing the toxicities of the hybrid cry1acs fused with different heterogenous genes provided guidance for the fusion expression of cry proteins.in order to provide guidance for selecting suitable heterogenous gene that can efficiently enhance toxicity or broaden insecticidal spectrum of cry1ac through fusion expression, two hybrid cry1acs fused with chitinase-encoding gene tchib and neurotoxin gene hwtx-1 respectively were constructed and their toxicities were compared. a bacillus thuringiensis strain harboring the cry1ac gene in vector pht315 was used as control. bioassay revealed that lc(50) (after 72 h) of cry1ac protoxin was 41.01 μ ...201222806817
impact of transgenic cotton varieties on activity of enzymes in their rhizosphere.the impact of five bacillus thuringiensis (bt) cotton varieties and their respective isogenic non-bt(nbt) isolines (ankur-2534, mech-6304, rch-317, ankur-651 and mech-6301) was assessed on the key soil enzymes i.e., dehydrogenase, alkaline phosphatase and urease in their rhizosphere at four growth stages of the crop, namely vegetative, flowering, bolling and harvesting. these varieties were grown on farmer's field in villages 22 miles and 24 miles of ganganagar district of rajasthan state in ind ...201222803335
effects of two varieties of bacillus thuringiensis maize on the biology of plodia interpunctella.on the market since 1996, genetically modified plants expressing an insecticidal toxin (cry toxin stemmed from bacillus thuringiensis) target several lepidopteran and coleopteran pests. in this study, we assessed the impact of two varieties of bt maize producing different toxins (cry1ab or cry1fa, respectively) on the biology of a storage pest: plodia interpunctella (hübner) (lepidoptera: pyralidae). the indianmeal moths were susceptible to both toxins but showed an escape behavior only from cry ...201222778907
lack of cry1fa binding to the midgut brush border membrane in a resistant colony of plutella xylostella moths with a mutation in the abcc2 locus.previous studies reported "mode 1" bacillus thuringiensis resistance in a colony of diamondback moths (no-qa), and recently, this resistance has been mapped to an abc transporter (abcc2) locus. we report the lack of binding of cry1fa to insects derived from this colony and compare our data with those from other insects with abcc2-associated resistance.201222773634
weak transcription of the cry1ac gene in nonsporulating bacillus thuringiensis cells.the cry1ac gene of bacillus thuringiensis subsp. kurstaki hd-73 (b. thuringiensis hd-73) is a typical example of a sporulation-dependent crystal gene and is controlled by sigma e and sigma k during sporulation. to monitor the production and accumulation of cry1ac at the cellular level, we developed a green fluorescent protein-based reporter system. the production of cry1ac was monitored in spo0a, sige, and sigk mutants, and these mutants were able to express the cry1ac-green fluorescent protein ...201222773626
alteration of leaf metabolism in bt-transgenic rice (oryza sativa l.) and its wild type under insecticide stress.insecticide is always used to control the damage from pests, while the potential influence on plants is rarely known. time-course metabolic changes of wild and bacillus thuringiensis (bt) transgenic rice (oryza sativa l.) plants after insecticide treatment were investigated by using gas chromatography-mass spectrometry (gc-ms). a combined statistical strategy of 2-way anova and multivariate analyses (principal component analysis and hierarchal cluster analysis) was performed to find the stress-a ...201222768924
the dynamics of cooperative bacterial virulence in the field.laboratory experiments have shown that the fitness of microorganisms can depend on cooperation between cells. although this insight has revolutionized our understanding of microbial life, results from artificial microcosms have not been validated in complex natural populations. we investigated the sociality of essential virulence factors (crystal toxins) in the pathogen bacillus thuringiensis using diamondback moth larvae (plutella xylostella) as hosts. we show that toxin production is cooperati ...201222767928
investigation of the cry4b-prohibitin interaction in aedes aegypti cells.bacillus thuringiensis (bt) produces insecticidal toxins active against insects. cry4b, one of the major insecticidal toxins produced by bt subsp. israelensis, is highly toxic to mosquitoes in the genus aedes: the major vectors of dengue, yellow fever, and chikungunya. previous work has shown that cry4b binds to several mid-gut membrane proteins in aedes aegypti larvae including prohibitin, a protein recently identified as a receptor that also mediates entry of dengue virus into aedes cells. thi ...201222767320
vip3a resistance alleles exist at high levels in australian targets before release of cotton expressing this toxin.crops engineered to produce insecticidal crystal (cry) proteins from the soil bacterium bacillus thuringiensis (bt) have revolutionised pest control in agriculture. however field-level resistance to bt has developed in some targets. utilising novel vegetative insecticidal proteins (vips), also derived from bt but genetically distinct from cry toxins, is a possible solution that biotechnical companies intend to employ. using data collected over two seasons we determined that, before deployment of ...201222761737
economic impacts and impact dynamics of bt (bacillus thuringiensis) cotton in india.despite widespread adoption of genetically modified crops in many countries, heated controversies about their advantages and disadvantages continue. especially for developing countries, there are concerns that genetically modified crops fail to benefit smallholder farmers and contribute to social and economic hardship. many economic studies contradict this view, but most of them look at short-term impacts only, so that uncertainty about longer-term effects prevails. we address this shortcoming b ...201222753493
isolation of single chain variable fragment (scfv) specific for cry1c toxin from human single fold scfv libraries.as bioinsecticides bacillus thuringiensis cry1c δ-endotoxins also have been used in genetically modified crops worldwide since last century. in this study, single chain variable fragments (scfvs), which could specifically recognize and detect cry1c in food samples, were isolated from naive phage displayed human antibody libraries (tomlinson i + j) by iterative affinity selection procedure instead of immunization process. with increasing selection pressure, after four rounds of panning, three ind ...201222982116
development of dipsticks for simultaneous detection of vip3a and cry1ab/cry1ac transgenic proteins.the number of genetically modified (gm) crops being cultivated and its produce reaching market is increasing every year. the transgenes (vip3a, cry1ab, and cry1ac) from bacillus thuringiensis are being used by plant breeders, apart from other transgenes for developing insect pest-resistant gm crops. it is therefore necessary to develop an easy, rapid, and reliable detection assay to discriminate gm crops and non-gm crops. dipstick strips using colloidal gold-labeled polyclonal antibodies were de ...201222970582
qualitative analysis of the fluorophosphonate-based chemical probes using the serine hydrolases from mouse liver and poly-3-hydroxybutyrate depolymerase (phaz) from bacillus thuringiensis.the serine hydrolase family consists of more than 200 members and is one of the largest enzyme families in the human genome. although up to 50 % of this family remains unannotated, there are increasing evidences that activities of certain serine hydrolases are associated with diseases like cancer neoplasia, invasiveness, etc. by now, several activity-based chemical probes have been developed and are applied to profile the global activity of serine hydrolases in diverse proteomes. in this study, ...201222941070
mathematical relationships between spore concentrations, delta-endotoxin levels, and entomotoxicity of bacillus thuringiensis preparations produced in different fermentation media.mathematic relationships between spore concentrations, delta-endotoxin concentrations and entomotoxicity (tx) of bacillus thuringiensis var. kurstaki hd-1 (btk hd-1) preparations produced in six different media were analysed. the relationship between delta-endotoxin and spore concentration and sptx-spore (specific tx per 1000 spore) and spore concentration produced in the different media (starch industry wastewater (siw) with total solids (ts) concentration of 15g/l, siw with ts of 30g/l, siw su ...201222940334
observations on house fly larvae midgut ultrastructure after brevibacillus laterosporus ingestion.the pathological and histopathological course caused by brevibacillus laterosporus on house fly larvae has been investigated conducting observations on insect behavior and midgut ultrastructure. after dissection and fixation, gut tissues were analyzed under transmission electron microscopy (tem) in order to compare in vivo-treated and non-treated (control) fly specimens. treated larvae showed extensively reduced feeding and growth rate, then became sluggish and died within 72 h. a progressive mi ...201222935249
adaptation by western corn rootworm (coleoptera: chrysomelidae) to bt maize: inheritance, fitness costs, and feeding preference.we examined inheritance of resistance, feeding behavior, and fitness costs for a laboratory-selected strain of western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), with resistance to maize (zea maize l.) producing the bacillus thuringiensis berliner (bt) toxin cry3bb1. the resistant strain developed faster and had increased survival on bt maize relative to a susceptible strain. results from reciprocal crosses of the resistant and susceptible strains indicate ...201222928323
western corn rootworm larval movement in smartstax seed blend scenarios.insect resistance management (irm) can extend the lifetime of management options, but depends on extensive knowledge of the biology of the pest species involved for an optimal plan. recently, the environmental protection agency (epa) registered seed blends refuge for two of the transgenic bacillus thuringiensis (bt) corn products targeting the western corn rootworm, diabrotica virgifera virgifera leconte. larval movement between bt and isoline plants can be detrimental to resistance management f ...201222928304
dispersal behavior of neonate european corn borer (lepidoptera: crambidae) on bt corn.european corn borer, ostrinia nubilalis (hübner) (lepidoptera: crambidae), has historically been a significant economically important insect pest of corn (zea mays l.) in the united states and canada. the development in the 1990s of genetically modified corn expressing genes derived from bacillus thuringiensis (bt) that encodes insecticidal crystalline (cry) proteins has proven to be effective in controlling this insect as well as other corn pests. the purpose of this study was to assess the mov ...201222928300
the utility of camptothecin as a synergist of bacillus thuringiensis var. kurstaki and nucleopolyhedroviruses against trichoplusia ni and spodoptera exigua.we studied the effect of combining microbial pesticides with camptothecin (cpt) on the mortality of two lepidopteran insects: trichoplusia ni (hübner) and spodoptera exigua (hübner). cpt is an alkaloid that is often used as an anticancer agent. here, cpt was evaluated as a microbial pesticide synergist of bacillus thuringiensis (bt) and insect baculovirus. the toxicity of cpt and its synergistic effects on two microbial pesticides were studied using the diet overlay method. bioassay results show ...201222928294
acute toxicities and sublethal effects of some conventional insecticides on trichogramma chilonis (hymenoptera: trichogrammatidae).the acute toxicity of 10 conventional insecticides to adult of trichogramma chilonis ishii (hymenoptera: trichogrammatidae) was bioassayed by membrane method, and then their sublethal effects on the parasitoid were evaluated in the laboratory. based on sublethal concentration (lc30) values at 8 h after treatment, we determined that adult t. chilonis were the most susceptible to chlorfenapyr, followed by fipronil, spinosad, avermectins, beta-cypermethrin, and cartap, with lethal concentration (lc ...201222928293
ser-substituted mutations of cys residues in bacillus thuringiensis vip3aa7 exert a negative effect on its insecticidal activity.vegetative insecticidal proteins (vips), which were produced by bacillus thuringiensis during its vegetative growth stage, display a broad insecticidal spectrum to lepidoptera larvae. sequence alignment of the vip3a-type indicates that three cysteine residues were conserved in vip3a-type proteins. to determine whether these conserved cysteine residues contributed to the insecticidal activity, the three residues were respectively substituted with serine in the vip3aa7 protein by site-directed mut ...201222875104
improvement of crystal solubility and increasing toxicity against caenorhabditis elegans by asparagine substitution in block 3 of bacillus thuringiensis crystal protein cry5ba.the crystal proteins from bacillus thuringiensis are widely used for their specific toxicity against insects and nematodes. the highly conserved sequence blocks play an important role in cry protein stability and flexibility, the basis of toxicity. the block 3 in cry5ba subfamily has a shorter sequence (only 12 residues) and more asparagine residues than that of others which harbor about 48 residues but only one asparagine. based on the theoretical structure model of cry5ba, all three asparagine ...201222865071
vip3c, a novel class of vegetative insecticidal proteins from bacillus thuringiensis.three vip3 genes were identified in two bacillus thuringiensis spanish collections. sequence analysis revealed a novel vip3 protein class (vip3c). preliminary bioassays of larvae from 10 different lepidopteran species indicated that vip3ca3 caused more than 70% mortality in four species after 10 days at 4 μg/cm(2).201222865065
the halo effect: suppression of pink bollworm on non-bt cotton by bt cotton in china.in some previously reported cases, transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce bt toxins. here we used 16 years of field data to determine if bt cotton caused this "halo effect" against pink bollworm (pectinophora gossypiella) in six provinces of the yangtze river valley of china. in this region, the percentage of cotton hectares pl ...201222848685
production of the 14c-labeled insecticidal protein cry1ab for soil metabolic studies using a recombinant escherichia coli in small-scale batch fermentations.insecticidal cry proteins naturally produced by bacillus thuringiensis are a major recombinant trait expressed by genetically modified crops. they are released into the soil during and after cropping. the objective of this study was to produce (14)c-labeled cry1ab proteins for soil metabolic studies in scope of their environmental risk assessment. cry1ab was synthesized as a protoxin by escherichia coli hb101 pmp in 200-ml liquid batch culture fermentations and purified from inclusion bodies aft ...201222846901
identification of a calmodulin-binding site within the domain i of bacillus thuringiensis cry3aa toxin.bacillus thuringiensis cry3aa toxin is a coleopteran specific toxin highly active against colorado potato beetle (cpb).we have recently shown that cry3aa toxin is proteolytically cleaved by cpb midgut membrane associated metalloproteases and that this cleavage is inhibited by adam metalloprotease inhibitors. in the present study, we investigated whether the cry3aa toxin is a calmodulin (cam) binding protein, as it is the case of several different adam shedding substrates. in pull-down assays usi ...201222836907
deltamethrin-induced genotoxicity and testicular injury in rats: comparison with biopesticide.deltamethrin is a synthetic pyrethroid insecticide used extensively in pest control. aim of the current study was to investigate the ability of deltamethrin-based commercial formulation to induce genotoxicity and testicular injury in rats in comparison to the use of the biopesticide; bacillus thuringiensis. rats were divided into three groups: group i (del) received deltamethrin, 5 mg/kgb.w./day orally, in corn oil. group ii (biopesticide, b. thuringiensis) received oral suspension of the biopes ...201222889898
testing potential effects of maize expressing the bacillus thuringiensis cry1ab endotoxin (bt maize) on mycorrhizal fungal communities via dna- and rna-based pyrosequencing and molecular fingerprinting.the cultivation of genetically modified (gm) crops has increased significantly over the last decades. however, concerns have been raised that some gm traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (amf), potentially leading to alterations in soil functioning. here, we test two maize varieties expressing the bacillus thuringiensis cry1ab endotoxin (bt maize) for their effects on soil am fungal communities. we target both fungal dna and rna, which is new f ...201222885748
functional significance of membrane associated proteolysis in the toxicity of bacillus thuringiensis cry3aa toxin against colorado potato beetle.bacillus thuringiensis cry toxins are widely used as biocontrol agents in bioinsecticides and transgenic plants. in the three domain-cry toxins, domain ii has been identified as an important determinant of their highly specific activity against insects. in this work, we assessed the role in membrane associated proteolysis and toxicity in colorado potato beetle (cpb) of a previously reported adam recognition motif present in cry3aa toxin domain ii. we used site-directed mutagenesis to modify the ...201222884605
molecular characterization of novel serovars of bacillus thuringiensis isolates from india.novel bacillus thuringiensis isolates gs4, gn24 and up1 were isolated and characterized by determination of serotyping, insecticidal protein by sds-page, plasmid composition, cry gene content and insect toxicity. serologically two isolates gs4 and up1 were allocated to the h3abce which is a new serovar while isolate gn24 was of h3ab type. isolate gs4 produced flat crystal inclusions while up1 produced cuboidal crystals. pcr analysis found that both isolates contained cry1 and cry1ac genes. the m ...201223997321
a novel cry2ab gene from the indigenous isolate bacillus thuringiensis subsp. kurstaki.a novel cry2ab gene was cloned and sequenced from the indigenous isolate of bacillus thuringiensis subsp. kurstaki. this gene was designated as cry2ab25 and its sequence revealed an open reading frame of 1,902 bp encoding a 633 aa protein with calculated molecular mass of 70 kda and pi value of 8.98. the amino acid sequence of the cry2ab25 protein was compared with previously known cry2ab toxins, and the phylogenetic relationships among them were determined. the deduced amino acid sequence of th ...201222297230
increased resistance of bt aspens to phratora vitellinae (coleoptera) leads to increased plant growth under experimental conditions.one main aim with genetic modification (gm) of trees is to produce plants that are resistant to various types of pests. the effectiveness of gm-introduced toxins against specific pest species on trees has been shown in the laboratory. however, few attempts have been made to determine if the production of these toxins and reduced herbivory will translate into increased tree productivity. we established an experiment with two lines of potted aspens (populus tremula×populus tremuloides) which expre ...201222292004
activity of a brazilian strain of bacillus thuringiensis israelensis against the cotton boll weevil anthonomus grandis boheman (coleoptera: tenebrionidae).a brazilian bacillus thuringiensis subspecies israelensis, toxic to diptera, including mosquitoes, was found also to show toxicity to the coleopteran boll weevil anthonomus grandis boheman at an equivalent level to that of the standard coleopteran-active b. thuringiensis subspecies tenebrionis t08017. recombinant b. thuringiensis strains expressing the individual cyt1aa, cry4aa, cry4ba and cry11aa toxins from this strain were assessed to evaluate their potential contribution to the activity agai ...201223950011
optimization of medium composition for the production of mosquitocidal toxins from bacillus thuringiensis subsp. israelensis.optimization of chicken feather (cf) based culture medium for the production of bacillus thuringiensis subsp. israelensis (bti) biomass in combination with the agro industrial by-product (coconut cake, cc) and manganese chloride (mncl2) has been evaluated. the biomass yield of bti spore/crystal toxin was highest (12.06 g/l) from the test medium (cf+cc+mncl2) compared to the reference medium (luria bertani, lb). toxicity assay with bti produced from the test medium against mosquito vectors (culex ...201222279944
analysis of opportunities and challenges in patenting of bacillus thuringiensis insecticidal crystal protein genes.bacillus thuringiensis (bt) is the most widely used microbial control agent. the broad spectrum of susceptible hosts, production on artificial media and ease of application has caused the widespread use of this bacterium against several pests in agriculture, forest and vectors of human diseases. b.thuringiensis toxins are highly species specific which provide economic, environmental benefits, potential for future control and spread of the technology worldwide. this makes the b. thuringiensis cry ...201222239684
large-scale, spatially-explicit test of the refuge strategy for delaying insecticide resistance.the refuge strategy is used worldwide to delay the evolution of pest resistance to insecticides that are either sprayed or produced by transgenic bacillus thuringiensis (bt) crops. this strategy is based on the idea that refuges of host plants where pests are not exposed to an insecticide promote survival of susceptible pests. despite widespread adoption of this approach, large-scale tests of the refuge strategy have been problematic. here we tested the refuge strategy with 8 y of data on refuge ...201222215605
safety assessment of transgenic bacillus thuringiensis rice t1c-19 in sprague-dawley rats from metabonomics and bacterial profile perspectives.bacillus thuringiensis rice is facing commercialization as the main food source in the near future. the unintended effects of genetically modified (gm) organisms are the most important barriers to their promotion. we aimed to establish a new in vivo evaluation model for genetically modified foods by using metabonomics and bacterial profile approaches. t1c-19 rice flour or its transgenic parent mh63 was used at 70% wt/wt to produce diets that were fed to rats for ∼ 90 days. urine metabolite chang ...201222215564
mosquito larvicidal and pupicidal efficacy of solanum xanthocarpum (family: solanaceae) leaf extract and bacterial insecticide, bacillus thuringiensis, against culex quinquefasciatus say (diptera: culicidae).the bio-efficacy of solanum xanthocarpum leaf extract and bacterial insecticide, bacillus thuringiensis, were assessed against the first to fourth instar larvae and pupae of culex quinquefasciatus, under the laboratory conditions. the medicinal plants were collected from the outskirt bharathiar university, coimbatore, tamil nadu, india. the shade dried plant materials were extracted by employing the soxhlet apparatus with ethanol (organic solvent) for 8 h and filtered. the extracts were concentr ...201222215195
assessing the role of non-cotton refuges in delaying helicoverpa armigera resistance to bt cotton in west africa.non-cotton host plants without bacillus thuringiensis (bt) toxins can provide refuges that delay resistance to bt cotton in polyphagous insect pests. it has proven difficult, however, to determine the effective contribution of such refuges and their role in delaying resistance evolution. here, we used biogeochemical markers to quantify movement of helicoverpa armigera moths from non-cotton hosts to cotton fields in three agricultural landscapes of the west african cotton belt (cameroon) where bt ...201225568029
pre-feeding of a glycolipid binding protein lec-8 from caenorhabditis elegans revealed enhanced tolerance to cry1ac toxin in helicoverpa armigera.crystal toxins from bacillus thuringiensis bind to glycolipids and glycoproteins using two different lectin domains in the toxin protein. our previous observations suggested that the sequestration of crystal toxin depends on the functional interaction of a toxin lectin with glycolipids. given the finding that competition of a galectin lec-8 with cry5b for binding to glycolipids resulting in reduced bt toxicity in nematode, it is interesting to explore the role of lec-8 in insects. here, we repor ...201224371572
in vitro uptake of 140 kda bacillus thuringiensis nematicidal crystal proteins by the second stage juvenile of meloidogyne hapla.plant-parasitic nematodes (ppns) are piercing/sucking pests, which cause severe damage to crops worldwide, and are difficult to control. the cyst and root-knot nematodes (rkn) are sedentary endoparasites that develop specialized multinucleate feeding structures from the plant cells called syncytia or giant cells respectively. within these structures the nematodes produce feeding tubes, which act as molecular sieves with exclusion limits. for example, heterodera schachtii is reportedly unable to ...201222737212
two new brazilian isolates of bacillus thuringiensis toxic to anticarsia gemmatalis (lepidoptera: noctuidae).bacillus thuringiensis is a bacterium used for biopesticides production and pest-resistant plants due to the synthesis of protein crystals by cry genes, which are effective in controlling several insect orders such as lepidoptera. this work aimed at the evaluation and characterisation of two new b. thuringiensis isolates active against a. gemmatalis (hübner 1818) larvae, which is the soybean major pest. the results showed that bt117-4 isolate amplified fragments corresponding to cry2 and cry9 ge ...201222735145
isolation of bacillus thuringiensis strains that contain dipteran-specific cry genes from ilha bela (são paulo, brazil) soil samples.the entomophatogenic bacterium bacillus thuringiensis produces crystal proteins, named cry proteins which are encoded by the cry genes. this bacterium is used on biological control of important economical pests, as well as in the control of disease´s vectors, such as aedes aegypti, a mosquito that transmits the dengue viruses. isolates of this bacterium can be characterized by the content of cry genes and this prediction helps target different insect orders. in this research, we isolated 76 colo ...201222735130
widespread adoption of bt cotton and insecticide decrease promotes biocontrol services.over the past 16 years, vast plantings of transgenic crops producing insecticidal proteins from the bacterium bacillus thuringiensis (bt) have helped to control several major insect pests and reduce the need for insecticide sprays. because broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests, the decrease in use of insecticide sprays associated with bt crops could enhance biocontrol services. however, this hypothesis has not been tested in terms of ...201222722864
determination of cry toxin activity and identification of an aminopeptidase n receptor-like gene in asymmathetes vulcanorum (coleoptera: curculionidae).an emergent pest is the weevil asymmathetes vulcanorum, an insect that attacks colombian potato areas. here, some cry proteins from the entomopathogenic bacteria bacillus thuringiensis were evaluated as biological control strategy. it was found that cry1b protoxin caused a mortality of 40% with a dose of 8000 ng/cm(2). also in this research, it was identified a full length cdna of an aminopeptidase n, a possible cry protein receptor located in the insect midgut. this is the first report about b. ...201222721915
fusing the vegetative insecticidal protein vip3aa7 and the n terminus of cry9ca improves toxicity against plutella xylostella larvae.bacillus thuringiensis insecticidal crystal proteins (icps) and vegetative insecticidal proteins (vips) have been widely used as a kind of safe bio-insecticides. a problem that has been of concern worldwide is how to improve their insecticidal activities. in this study, to determine the synergism between vips and icps effect on insecticidal activity, a construct that produces a chimeric protein of the vip3aa7 and the n terminus ofcry9ca, named v3ac9c, was expressed in escherichia coli bl21 cells ...201222718249
phenotypic and genotypic characterization of b.t.ldc-391 strain that produce cytocidal proteins against human cancer cells.an indigenous bacillus thuringiensis strain b.t.ldc-391 producing cytocidal proteins against human colon cancer cell line, hct-116, was subjected to phenotypic and genotypic characterization to evaluate its relatedness to b.anthracis. the morphological features of this strain were meta-analyzed with data of other parasporin and insecticidal protein producing bacillus thuringiensis strains. the conventional biochemical analysis and antibiotic sensitivity test proved it as an ampicillin resistant ...201222715300
a 90-day subchronic feeding study of genetically modified maize expressing cry1ac-m protein in sprague-dawley rats.the cry1ac-m gene, coding one of bacillus thuringiensis (bt) crystal proteins, was introduced into maize h99 × hi iib genome to produce insect-resistant gm maize bt-38. the food safety assessment of the bt-38 maize was conducted in sprague-dawley rats by a 90-days feeding study. we incorporated maize grains from bt-38 and h99 × hi iib into rodent diets at three concentrations (12.5%, 25%, 50%) and administered to sprague-dawley rats (n=10/sex/group) for 90 days. a commercialized rodent diet was ...201222709787
proteomic analysis of bacillus thuringiensis δphac mutant bmb171/phb(-1) reveals that the phb synthetic pathway warrants normal carbon metabolism.a phac knockout mutant from bacillus thuringiensis (bt) strain bmb171, named bmb171/phb(-1), was constructed. a physiological and metabolic investigation and a proteomic analysis were conducted for both δphac mutant and its parent strain. grown in peptone medium with 5 gram glucose per liter as sole carbon source, bmb171/phb(-1) produced various organic acids. here the excreted pyruvate, citrate, lactate, acetate and glutamate were quantitatively analyzed. deletion of phac gene from the bmb171 s ...201222705120
dna barcoding simplifies environmental risk assessment of genetically modified crops in biodiverse regions.transgenes encoding for insecticidal crystal (cry) proteins from the soil-dwelling bacterium bacillus thuringiensis have been widely introduced into genetically modified (gm) crops to confer protection against insect pests. concern that these transgenes may also harm beneficial or otherwise valued insects (so-called non target organisms, ntos) represents a major element of the environmental risk assessments (eras) used by all countries prior to commercial release. compiling a comprehensive list ...201222567120
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