Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| malaysian mosquitocidal soil bacterium (bacillus thuringiensis) strains with selective hemolytic and lectin activity against human and rat erythrocytes. | the objective of this study is to determine the role of carbohydrates on the toxic effect of parasporal inclusion proteins isolated from malaysian mosquitocidal bacillus thuringiensis (bt) strains on erythrocytes (human and rat). dose response analyses on the effect of these parasporal inclusions on human and rat erythrocytes suggest that toxin action is selective depending on bacterial strains and source of erythrocytes. results from this study suggest bt toxin is a lectin which recognizes spec ... | 2006 | 16771215 |
| characterization of bacillus thuringiensis strain bt185 toxic to the asian cockchafer: holotrichia parallela. | a new bacillus thuringiensis strain, bt185, was isolated from hebei soil samples in china. observations after transmission electron microscopy found that the strain produced spherical parasporal inclusions similar to that of the b. thuringiensis subsp. japonensis buibui strain, which showed toxicity to both anomala corpulenta and popillia japonica. the plasmid profile seen on an agarose gel revealed that bt185 contained six large bands of 191 kb, 161 kb, 104 kb, 84 kb, 56 kb, and 37 kb. sodium d ... | 2006 | 16775781 |
| cry1aa lacks stability elements at its 5'-utr but integrity of its transcription terminator is critical to prevent decay of its transcript. | we analyzed the influence of the 5' and 3' untranslated regions of the bacillus thuringiensis cry1aa on its mrna stability. although the cry1aa gene has a stable transcript (8 min), its 5' utr did not provide stability to the reporter gene uida. stability of cry1aa could be increased to 40 min by addition of an sp82 stability element at the 5' utr, suggesting that once the 5' and 3' ends were protected initiation of decay could be effectively blocked. we generated mutations in the transcription ... | 2006 | 16775783 |
| structural and functional analysis of the pre-pore and membrane-inserted pore of cry1ab toxin. | bacillus thuringiensis produces insecticidal cry proteins that are active against different insect species. the primary action of cry toxins is to lyse midgut epithelial cells in the target insect by forming lytic pores on the apical membrane. after interaction with cadherin receptor, cry proteins undergo conformational changes from a monomeric structure to a pre-pore-oligomeric form that is able to interact with a second gpi-anchored aminopeptidase-n receptor and then insert into lipid membrane ... | 2006 | 16777138 |
| pathogenicity of intrathoracically administrated bacillus thuringiensis spores in blatta orientalis. | the ability of bacillus thuringiensis to produce septicaemia in periplaneta americana and blatta orientalis has been investigated. spores and crystals from several wild-type strains as well as spores of a b. thuringiensis crystal-deficient mutant, were first orally administrated at high doses, and no significant mortality was recorded. intrathoracic injection of spore suspensions in p. americana revealed that this species is not very susceptible to b. thuringiensis spores. b. orientalis, by cont ... | 2006 | 16777139 |
| vip3a is responsible for the potency of bacillus thuringiensis 9816c culture supernatant against helicoverpa armigera and spodoptera exigua. | culture supernatant of bacillus thuringiensis 9816c had high toxicity against helicoverpa armigera and spodoptera exigua. however, it lost insecticidal activities after being bathed in boiling water for 5 min. acrystalliferous mutants of bt9816c (bt9816c-np1 and bt9816c-np2) cured of its endogenous plasmids no longer possessed vip3a gene and toxicity. the 89 kd protein which existed in bt9816c supernatant disappeared in the two mutants' supernatant; nevertheless, the two mutants still exhibited ... | 2006 | 16778351 |
| mycotoxin reduction in bt corn: potential economic, health, and regulatory impacts. | genetically modified (gm) bt corn, through the pest protection that it confers, has lower levels of mycotoxins: toxic and carcinogenic chemicals produced as secondary metabolites of fungi that colonize crops. in some cases, the reduction of mycotoxins afforded by bt corn is significant enough to have an economic impact, both in terms of domestic markets and international trade. in less developed countries where certain mycotoxins are significant contaminants of food, bt corn adoption, by virtue ... | 2006 | 16779644 |
| effects of commercial microbial products on the immune system of elliptio complanata mussels. | 2006 | 16786456 | |
| laboratory and field tests of spray-dried and granular formulations of a bacillus thuringiensis strain with insecticidal activity against the sugarcane borer. | formulations of bacillus thuringiensis berliner (bt) with insecticidal activity against the sugarcane borer, diatraea saccharalis fabricius (lepidoptera: pyralidae), were developed and tested under laboratory and field conditions. the formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a bt var. kurstaki gm-34 strain from a non-sugarcane region as the active ingredien ... | 2006 | 16786544 |
| a mechanism of cell death involving an adenylyl cyclase/pka signaling pathway is induced by the cry1ab toxin of bacillus thuringiensis. | many pathogenic organisms and their toxins target host cell receptors, the consequence of which is altered signaling events that lead to aberrant activity or cell death. a significant body of literature describes various molecular and cellular aspects of toxins associated with bacterial invasion, colonization, and host cell disruption. however, there is little information on the molecular and cellular mechanisms associated with the insecticidal action of bacillus thuringiensis (bt) cry toxins. r ... | 2006 | 16788061 |
| the enhancin-like metalloprotease from the bacillus cereus group is regulated by the pleiotropic transcriptional activator plcr but is not essential for larvicidal activity. | bacillus cereus group bacteria produce virulence factors. many of these are regulated by the pleiotropic transcriptional activator plcr, which is implicated in insect virulence. in silico analysis of the b. cereus strain atcc14579 genome showed an enhancin-like gene preceded by a typical plcr binding sequence. the gene is predicted to encode a polypeptide showing 23-25% identity with enhancins from several baculoviruses and 31% with that of yersinia pestis. viral enhancin acts after oral infecti ... | 2006 | 16790012 |
| antimicrobial activities of human beta-defensins against bacillus species. | natural defences in the human body function to protect us from numerous environmental toxins and exposure to potential harmful biological agents. an important frontline defence is antimicrobial peptides. these peptides occur at environmental interfaces and serve to limit bacterial invasion. there has been little work comparing specific peptides as potential antimicrobial compounds. in this study, we evaluated the antimicrobial activity of peptides from the human beta-defensin (hbd) family agains ... | 2006 | 16797165 |
| expression of cry1ac cadherin receptors in insect midgut and cell lines. | cadherin-like proteins have been identified as putative receptors for the bacillus thuringiensis cry1a proteins in heliothis virescens and manduca sexta. immunohistochemistry showed the cadherin-like proteins are present in the insect midgut apical membrane, which is the target site of cry toxins. this subcellular localization is distinct from that of classical cadherins, which are usually present in cell-cell junctions. immunoreactivity of the cadherin-like protein in the insect midgut was enha ... | 2006 | 16797582 |
| cry toxin mode of action in susceptible and resistant heliothis virescens larvae. | many pest insect species are effectively controlled by bacillus thuringiensis (bt) cry toxins delivered in plants and biopesticides. since the insect midgut epithelium contains receptors and other molecules that determine bt toxicity, characterization of these molecules is necessary for sustained usage of bt toxins. studies of bt susceptible and resistant strains of heliothis virescens have provided insights into resistance mechanisms and toxin receptors. for example, the first gene identified a ... | 2006 | 16797583 |
| chemical-induced autoexcision of selectable markers in elite tomato plants transformed with a gene conferring resistance to lepidopteran insects. | marker-free transgenic tomato plants harboring a synthetic bacillus thuringiensis endotoxin gene, cryiac, were obtained by using a chemically regulated, cre/loxp-mediated site-specific dna recombination system, in which the selectable marker neomycin phosphotransferase gene flanked by two directly oriented loxp sites was located between the cauliflower mosaic virus 35s promoter and a promoterless cryiac. upon induction by 2 microm beta-estradiol, sequences encoding the selectable marker and cre ... | 2006 | 16802102 |
| pronase digestion of brush border membrane-bound cry1aa shows that almost the whole activated cry1aa molecule penetrates into the membrane. | bacillus thuringiensis insecticidal proteins, cry toxins, following ingestion by insect larvae, induce insecticidal effect by penetrating the brush border membranes (bbm) of midgut epithelial cells. purified, activated b. thuringiensis cry1aa bound to bombyx mori bbmv or unbound cry1aa were vigorously digested with pronase. both digests were compared by western blotting. free cry1aa was digested to alpha-helix and/or to amino acids at 1 mg pronase/ml within 2.4 h at 37 degrees c. whereas, bbmv-b ... | 2006 | 16807030 |
| cytocidal actions of parasporin-2, an anti-tumor crystal toxin from bacillus thuringiensis. | parasporin-2, a new crystal protein derived from noninsecticidal and nonhemolytic bacillus thuringiensis, recognizes and kills human liver and colon cancer cells as well as some classes of human cultured cells. here we report that a potent proteinase k-resistant parasporin-2 toxin shows specific binding to and a variety of cytocidal effects against human hepatocyte cancer cells. cleavage of the n-terminal region of parasporin-2 was essential for the toxin activity, whereas c-terminal digestion w ... | 2006 | 16809341 |
| diabrotica virgifera virgifera (coleoptera: chrysomelidae) larval feeding behavior on transgenic maize (mon 863) and its isoline. | diabrotica species (coleoptera: chrysomelidae) larval behavior studies have posed a challenge to researchers because of the subterranean life cycle of this pest. to fully understand how the western corn rootworm, diabrotica virgifera virgifera leconte, injures the maize, zea mays l., root system, its behavior must be studied. for example, larvae that can detect an area of the root that has a lower amount of toxin, whether from an insecticide or a transgenic maize plant, have an increased chance ... | 2006 | 16813304 |
| cannibalism of helicoverpa zea (lepidoptera: noctuidae) from bacillus thuringiensis (bt) transgenic corn versus non-bt corn. | because of the importance of cannibalism in population regulation of helicoverpa zea (boddie) (lepidoptera: noctuidae) in corn, zea mays l., it is useful to understand the interactions between bacillus thuringiensis (bt) transgenic corn and cannibalism. to determine the effects of bt corn on cannibalism in h. zea, pairs of the same or different instars were taken from bt or non-bt corn and placed on artificial diet in proximity. cannibalism occurred in 91% of pairs and was approximately 7% great ... | 2006 | 16813305 |
| potential of selective insecticides for managing uraba lugens (lepidoptera: nolidae) on eucalypts. | the leaf skeletonizer uraba lugens walker (lepidoptera: nolidae), an australian species, locally known as "gumleaf skeletonizer", is well established in new zealand. this insect has the potential to become a serious pest of forestry and amenity eucalypts (eucalyptus spp.) and is the focus of a long-term management program. the use of synthetic chemical or biological insecticides is one possible control method within an integrated control program. a series of dose-response trials were conducted u ... | 2006 | 16813312 |
| resistance monitoring of helicoverpa armigera (lepidoptera: noctuidae) to bt insecticidal protein during 2001-2004 in china. | susceptibility of helicoverpa armigera (hübner) (lepidoptera: noctuidae) field populations to the crylac toxin of bacillus thuringiensis berliner (bt) were monitored from 1997 to 2004 in china. during 2001-2004, 53 strains from the bt cotton planting region were sampled. the range of concentration producing 50% inhibition of larval development to third instar (ic50) values among different populations in 2001, 2002, 2003, and 2004 was 0.014-0.046, 0.010-0.062, 0.005-0.062, and 0.005-0.035 microg/ ... | 2006 | 16813327 |
| effect of entomopathogenic nematodes on the fitness cost of resistance to bt toxin crylac in pink bollworm (lepidoptera: gelechiidae). | the widespread use of crop plants genetically engineered to produce toxins from the bacterium bacillus thuringiensis (bt) imposes selection on insect populations to evolve resistance. the pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), is a major pest of cotton in the southwestern united states that is currently controlled with transgenic cotton that produces bt toxin cry1ac. previously reported theoretical work suggests that, in conjunction with a high dose/refuge ... | 2006 | 16813331 |
| effect of bacillus thuringiensis cry3bb1 protein on the feeding behavior and longevity of adult western corn rootworms (coleoptera: chrysomelidae). | the first transgenic corn hybrids expressing the bacillus thuringiensis (bt) cry3bb1 protein to control corn rootworm (diabrotica spp.) larvae were registered for commercial use in 2003. this study was conducted to investigate the effect of cry3bb1 protein in combination with a cucurbitacin bait on adult feeding and longevity of both organophosphate-resistant and -susceptible western corn rootworms, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae). in choice and no-choice tests ... | 2006 | 16813332 |
| differences in susceptibility and physiological fitness of mexican field trichoplusia ni strains exposed to bacillus thuringiensis. | the use of different commercial bacillus thuringiensis (bt) products in the bajio guanajuatense area in mexico began 12 yr ago, and resistance to bt in this area has been reported for plutella xylostella (l.) the current study provides a baseline response and resistance potential to bt in field and laboratory strains of bajio trichoplusia ni (hübner). differences in susceptibility to bt among t. ni populations were observed. t. ni neonates collected in romita, guanajuato, were more susceptible t ... | 2006 | 16813334 |
| effect of resistance to bacillus thuringiensis cotton on pink bollworm (lepidoptera: gelechiidae) response to sex pheromone. | fitness costs associated with resistance to transgenic crops producing toxins from bacillus thuringiensis (bt) could reduce male response to pheromone traps. such costs would cause underestimation of resistance frequency if monitoring was based on analysis of males caught in pheromone traps. to develop a dna-based resistance monitoring program for pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), we compared the response to pheromone traps of males with and without c ... | 2006 | 16813335 |
| sequence diversity of the bacillus thuringiensis and b. cereus sensu lato flagellin (h antigen) protein: comparison with h serotype diversity. | we set out to analyze the sequence diversity of the bacillus thuringiensis flagellin (h antigen [hag]) protein and compare it with h serotype diversity. some other bacillus cereus sensu lato species and strains were added for comparison. the internal sequences of the flagellin (hag) alleles from 80 bacillus thuringiensis strains and 16 strains from the b. cereus sensu lato group were amplified and cloned, and their nucleotide sequences were determined and translated into amino acids. the flagell ... | 2006 | 16820457 |
| molecular and insecticidal characterization of a cry1i protein toxic to insects of the families noctuidae, tortricidae, plutellidae, and chrysomelidae. | the most notable characteristic of bacillus thuringiensis is its ability to produce insecticidal proteins. more than 300 different proteins have been described with specific activity against insect species. we report the molecular and insecticidal characterization of a novel cry gene encoding a protein of the cry1i group with toxic activity towards insects of the families noctuidae, tortricidae, plutellidae, and chrysomelidae. pcr analysis detected a dna sequence with an open reading frame of 2. ... | 2006 | 16820473 |
| an ecological risk assessment of cry1f maize pollen impact to pale grass blue butterfly. | the intrinsic toxicity of lepidopteran-active bt proteins necessitates assessment of non-target risks associated with environmental release of transgenic crops expressing these proteins. principles of ecological risk assessment provide a means for assessing non-target risks when information regarding exposure to the toxin and species-specific effects are lacking. this is shown for the case of bt cry1f maize release in japan, where off-field pollen dissemination and effect on butterfly species is ... | 2006 | 16827552 |
| influence of the biophysical and biochemical environment on the kinetics of pore formation by cry toxins. | the effect of bacillus thuringiensis toxins on the permeability of the luminal membrane of manduca sexta midgut columnar epithelial cells is strongly influenced by several biophysical and biochemical factors, including ph, ionic strength, and divalent cations, suggesting an important role for electrostatic interactions. the influence of these factors can differ greatly, however, depending on the toxin being studied, even for closely related toxins such as cry1ac and cry1ca. in the present study, ... | 2006 | 16831627 |
| a metabonomic study of transgenic maize (zea mays) seeds revealed variations in osmolytes and branched amino acids. | the aim of the research was to investigate metabolic variations associated with genetic modifications in the grains of zea mays using metabonomic techniques. with this in mind, the non-targeted characteristic of the technique is useful to identify metabolites peculiar to the genetic modification and initially undefined. the results obtained showed that the genetic modification, introducing cry1ab gene expression, induces metabolic variations involving the primary nitrogen pathway. concerning the ... | 2006 | 16831843 |
| diversity of bacillus thuringiensis strains in the maize and bean phylloplane and their respective soils in colombia. | to evaluate the distribution of bacillus thuringiensis strains from maize and bean phylloplane and their respective soils. | 2006 | 16834598 |
| genetically engineered plants, endangered species, and risk: a temporal and spatial exposure assessment for karner blue butterfly larvae and bt maize pollen. | genetically engineered maize (zea mays) containing insecticidal endotoxin proteins from bacillus thuringiensis (bt) delta-endotoxin proteins has been adopted widely in the midwestern united states. the proteins are toxic to several lepidopteran species and because a variety of maize tissues, including pollen, may express the endotoxins, the probability of exposure to nontarget species, including endangered species, needs to be understood. the objective of this study was to assess the potential t ... | 2006 | 16834638 |
| activation process of the mosquitocidal delta-endotoxin cry39a produced by bacillus thuringiensis subsp. aizawai bun1-14 and binding property to anopheles stephensi bbmv. | most delta-endotoxins produced by bacillus thuringiensis require proteolytic processing in order to become active. the in vitro and in vivo activation processes of cry39a, a delta-endotoxin that is highly toxic to anopheles stephensi, were investigated. cry39a with a molecular mass of 72 kda was processed in vitro into a 60 kda fragment by trypsin and gut extract from a. stephensi larvae. n-terminal amino acid sequencing of the 60 kda fragment revealed that trypsin and the protease(s) in the gut ... | 2006 | 16837008 |
| restraining erwinia virulence by expression of n-acyl homoserine lactonase gene pro3a-aiia in bacillus thuringiensis subsp leesis. | to widen the biological control function of a genetically modified bacillus thuringiensis subsp leesis strain bmb-005, an acyl homoserine lactonase (ahl lactonase) gene aiia transcribed by the promoter of insecticidal crystal protein coding gene cry3a, was transformed into strain bmb-005. the amount of ahl lactonase protein produced by transformant bmb821a was 2.4-fold more than that produced by bmb-005. ahl-degradation assay showed that transformant bmb821a could degrade more ahls molecules tha ... | 2006 | 16838380 |
| ecological risk assessment for bt crops. | 2006 | 16841050 | |
| pyrolysis mass spectrometry for distinguishing potential hoax materials from bioterror agents. | pyrolysis mass spectrometry (pyms) was investigated as a rapid tool to distinguish potential bioterror hoax materials from samples containing pathogenic bacteria. a pyrolysis time-of-flight (tof) mass spectrometer equipped with an alternative ionization technique, metastable atom bombardment (mab), was used to produce sample spectra. these spectra were analyzed by principal component and discriminant analysis for pattern recognition. materials investigated were two strains of vibrio parahaemolyt ... | 2006 | 16841357 |
| characterization of bacillus anthracis-like bacteria isolated from wild great apes from cote d'ivoire and cameroon. | we present the microbiological and molecular characterization of bacteria isolated from four chimpanzees and one gorilla thought to have died of an anthrax-like disease in côte d'ivoire and cameroon. these isolates differed significantly from classic bacillus anthracis by the following criteria: motility, resistance to the gamma phage, and, for isolates from cameroon, resistance to penicillin g. a capsule was expressed not only after induction by co(2) and bicarbonate but also under normal growt ... | 2006 | 16855222 |
| laboratory and field evaluations of rhodojaponin-iii against the imported cabbage worm pieris rapae (l.) (lepidoptera: pieridae). | the activity of rhodojaponin-iii (r-iii), a grayanoid diterpene compound isolated from rhododendron molle g. don flowers, was determined under laboratory and field conditions as an antifeedant, stomach poison, contact toxicant and insect growth inhibitor against pieris rapae (l.) larvae. the median antifeedant concentration (afc(50)) values in no-choice leaf disc tests were 1.16 and 15.85 mg l(-1) at 24 h after treatment when tested against third and fifth instars respectively. the median lethal ... | 2006 | 16856122 |
| ovipositional and ovicidal effects of the microbial agent bacillus thuringiensis israelensis on culex quinquefasciatus say (diptera: culicidae). | the magnitude of oviposition as well as the size, shape and the number of eggs per of egg rafts egg raft were determined after gravid culex quinquefasciatus say oviposited on water treated with water dispersible granules (wdg) of bacillus thuringiensis ssp. israelensis (bti) and on untreated water. the mean number of eggs/raft was lower in the treated than in the untreated water. bti concentrations from 0.5 to 2.0mg/l affected the shape of egg rafts and number of eggs in each raft. as the concen ... | 2006 | 16859087 |
| feeding behavior of larval black flies (diptera: simuliidae) with and without exposure to bacillus thuringiensis var. israelensis. | behavioral time budgets were constructed for larval black flies of the simulium jenningsi and s. tuberosum groups in a recirculating flume. larvae spent the majority (54-80%) of time filter feeding. flick rates of the labral fans, which averaged 0.7-1.9 flicks/sec, did not differ significantly between regimens of 0 mg/l and 10 mg/l of food. larvae consistently flicked the fan nearest the water surface significantly more often than the lower fan. they also tended to flick the right fan more than ... | 2006 | 16859093 |
| a detection method of cryiac protein for identifying genetically modified rice using the lateral flow strip assay. | we examined the lateral flow strip assay for identifying unauthorized genetically modified (gm) rice. the gm rice expresses the bacillus thuringiensis (bt) toxin, cryiac protein, which confers tolerance to insects. the recombinant cryiac protein was prepared from the inclusion bodies of an e. coli. strain into which the cryiac gene had been inserted, using gel filtration chromatography. the lateral flow strip assay for the identification of gm cotton which also expresses cryiac protein, was appl ... | 2006 | 16862988 |
| preparation and evaluation of spore-specific affinity-augmented bio-imprinted beads. | a novel, affinity-augmented, bacterial spore-imprinted, bead material was synthesized, based on a procedure developed for vegetative bacteria. the imprinted beads were intended as a front-end spore capture/concentration stage of an integrated biological detection system. our approach involved embedding bead surfaces with bacillus thuringiensis kurstaki (bt) spores (as a surrogate for bacillus anthracis) during synthesis. subsequent steps involved lithographic deactivation using a perfluoroether; ... | 2006 | 16865337 |
| piezoelectric-excited millimeter-sized cantilever (pemc) sensors detect bacillus anthracis at 300 spores/ml. | piezoelectric-excited millimeter-sized cantilever (pemc) sensors consisting of a piezoelectric and a borosilicate glass layer with a sensing area of 2.48 mm2 were fabricated. antibody specific to bacillus anthracis (ba, sterne strain 7702) spores was immobilized on pemc sensors, and exposed to spores (300 to 3x10(6) spores/ml). the resonant frequency decreased at a rate proportional to the spore concentration and reached a steady state frequency change of 5+/-5 hz (n=3), 92+/-7 hz (n=3), 500+/-1 ... | 2006 | 16169715 |
| toxicological effect of indole and its azo dye derivatives on some microorganisms under aerobic conditions. | azo dyes are ubiquitous commercial chemicals that present unique environmental problems. the azo dyes in particular can undergo natural anaerobic degradation to potentially carcinogenic amines. they pose a major problem for water-treatment plants downstream. one strategy to remidate polluted surface contaminants is to make use of the degradative capacity of bacteria rather than using destructive chemical reactions. therefore, pathogenic and non-pathogenic microorganisms namely; bacillus thuringi ... | 2006 | 16165191 |
| a gpi-anchored alkaline phosphatase is a functional midgut receptor of cry11aa toxin in aedes aegypti larvae. | a 65 kda gpi (glycosylphosphatidyl-inositol)-anchored alp (alkaline phosphatase) was characterized as a functional receptor of the bacillus thuringiensis subsp. israelensis cry11aa toxin in aedes aegypti midgut cells. two (a 100 kda and a 65 kda) gpi-anchored proteins that bound cry11aa toxin were preferentially extracted after treatment of bbmv (brush boder membrane vesicles) from ae. aegypti midgut epithelia with phospholipase c. the 65 kda protein was further purified by toxin affinity chroma ... | 2006 | 16255715 |
| bioconversion of industrial wastewater and wastewater sludge into bacillus thuringiensis based biopesticides in pilot fermentor. | starch industry wastewater (sww), slaughterhouse wastewater (shww) and secondary sludges from three different wastewater treatment plants (jonquière--jqs, communauté urbaine de québec--cuqs and black lake-bls) were used as raw materials for the production of bacillus thuringiensis (bt) based biopesticides in a pilot scale fermentor (100 l working volume). the slaughterhouse wastewater exhibited the lowest bt growth and entomotoxcity (tx) potential (measured against spruce budworm) due to low ava ... | 2006 | 16242319 |
| efficient solubilization, activation, and purification of recombinant cry45aa of bacillus thuringiensis expressed as inclusion bodies in escherichia coli. | a cytotoxic protein cry45aa of bacillus thuringiensis expressed as inclusion bodies in escherichia coli was solubilized in 10 mm hcl. protein concentration of saturated solution of the recombinant cry45aa in 10 mm hcl was about 25 times higher than that in the buffer of previous method (in 50 mm sodium carbonate buffer, ph 10.5, containing 1 mm edta, and 10 mm dithiothreitol). the cry45aa solubilized in the acidic solution was activated by pepsin as an alternative to proteinase k in the previous ... | 2006 | 16307894 |
| characterization of a cry4ba-type gene of bacillus thuringiensis israelensis and evidence of the synergistic larvicidal activity of its encoded protein with cry2a delta-endotoxin of b. thuringiensis kurstaki on culex pipiens (common house mosquito). | a newly isolated strain of bacillus thuringiensis, named bupm97, was identified as affiliated to the israelensis subspecies. this strain was selected for its insecticidal activity against larvae of several dipteran insects, such as the common house mosquito (culex pipiens). a 5 kb ecori fragment, containing a cry4ba-type gene, named cry4blb, was cloned from bupm97. the sequencing of this gene revealed an open reading frame of 3411 bp encoding a protein of 1136 amino acid residues. similarity ana ... | 2006 | 16309381 |
| consequences for protaphorura armata (collembola: onychiuridae) following exposure to genetically modified bacillus thuringiensis (bt) maize and non-bt maize. | studies on the effect of genetically modified bacillus thuringiensis (bt) crops on true soil dwelling non-target arthropods are scarce. the objective of this study was to assess the influence of a 4-week exposure to two bt maize varieties (cry1ab) cascade and meb307 on the collembolan protaphorura armata. for comparison three non-bt maize varieties, rivaldo (isogenic to cascade), monumental (isogenic to meb307) and dk242, and two control diets based on baker's yeast (uncontaminated and contamina ... | 2006 | 16310913 |
| decolourisation and detoxification of synthetic molasses melanoidins by individual and mixed cultures of bacillus spp. | the decolourisation of synthetic melanoidins (i.e., gga, gaa, sga, and saa) by three bacillus isolates (bacillus thuringiensis (mtcc 4714), bacillus brevis (mtcc 4716) and bacillus sp. (mtcc 6506)) was studied. significant reduction in the values of physicochemical parameters was noticed alongwith the decolourisation of all four melanoidins (10% v/v). b. thuringiensis (mtcc 4714) caused maximum decolourisation followed by b. brevis (mtcc 4716) and bacillus sp. (mtcc 6506). a mixed culture compri ... | 2006 | 16321521 |
| new tool for spreading proteins to the environment: cry1ab toxin immobilized to bioplastics. | a new tool to provide an environmentally friendly way to deliver active proteins to the environment has been developed, based on the use of polyhydroxyalkanoate (pha, bioplastic) granules. to illustrate this novel approach, a derived cry1ab insect-specific toxin protein was in vivo immobilized into pha granules through the polypeptide tag biof. the new toxin, named fk-bt1, was shown to be active against sesamia nonagrioides (lepidoptera: noctuidae). the dose-mortality responses of the new toxin ... | 2006 | 16333620 |
| brush border membrane binding properties of bacillus thuringiensis vip3a toxin to heliothis virescens and helicoverpa zea midguts. | the binding properties of vip3a, a new family of bacillus thuringiensis insecticidal toxins, have been examined in the major cotton pests, heliothis virescens and helicoverpa zea. vip3a bound specifically to brush border membrane vesicles (bbmv) prepared from both insect larval midguts. in order to examine the cross-resistance potential of vip3a to the commercially available cry1ac and cry2ab2 toxins, the membrane binding site relationship among these toxins was investigated. competition binding ... | 2006 | 16337146 |
| an immuno-pcr method for detecting bacillus thuringiensis cry1ac toxin. | the cry1ac toxin is an insecticidal protein produced by bacillus thuringiensis var. kurstaki. recently, the gene encoding the toxin was genetically transformed into crop plants. a specific and sensitive method for detecting the cry1ac toxin would facilitate monitoring for this protein in crop and non-crop plants and also in foods. the purpose of this study was to develop an immuno-pcr technique for detecting this toxin. immuno-pcr combines the specificity of an elisa reaction with the sensitivit ... | 2006 | 16337224 |
| in situ studies on the time-dependent degradation of recombinant corn dna and protein in the bovine rumen. | an in situ technique was adopted to investigate the time-dependent ruminal degradation of chloroplast compared with recombinant dna of bt176 corn using conventional and quantitative pcr assays. in parallel, the cry1ab protein content and fragment sizes were determined by elisa and immunoblotting techniques. triplicate nylon bags filled with 5 g of each substrate (whole-plant isogenic, whole-plant transgenic, ensiled isogenic, and ensiled transgenic corn) were positioned within the rumen of 5 rum ... | 2006 | 16361500 |
| improved elisa method for screening human antigen-specific ige and its application for monitoring specific ige for novel proteins in genetically modified foods. | for monitoring the occurrence of ige antibody specific for novel proteins in genetically modified (gm) foods, elisa is the most convenient method. the levels of ige specific for recombinant proteins, phosphinothricin-n-acetyltransferase (pat), cp4-epsps, and cry9c were determined by elisa using the sera from patients allergic to known allergens. ovalbumin (ova) and ova-positive patient sera were used as positive control. in the elisa, 20-fold-diluted sera tested were mostly negative for the spec ... | 2006 | 16364525 |
| atomic force microscopy of bacillus spore surface morphology. | 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 curved upper surface of the spores. phase images showed a superficial grain structure with different le ... | 2006 | 16376084 |
| bacteria isolated from the different developmental stages and larval organs of the obligate parasitic fly, wohlfahrtia magnifica (diptera: sarcophagidae). | wohlfahrtia magnifica (diptera: sarcophagidae) is the major myiasis-causing fly species in the whole of eurasia for most important domestic animals. the aim of the present work was to obtain data on the culturable bacteria isolated under aerobic conditions from this fly: bacteria were isolated from all developmental stages (larvae, pupa, and imago) of wohlfahrtia magnifica, and the third-stage larval organs were also sampled. to determine the possible antagonistic effects between the dominant ba ... | 2006 | 16382282 |
| the role of a conserved histidine-tyrosine interhelical interaction in the ion channel domain of delta-endotoxins from bacillus thuringiensis. | the delta-endotoxin proteins are produced by bacillus thuringiensis during the sporulation phase of its life cycle. these proteins exhibit insecticidal activity through receptor-mediated ion channel formation. the mode of action of these proteins requires the conversion of the protein from a water-soluble conformation to a membrane-inserted conformation. while there is x-ray structure information for the soluble protein, no detailed structure exists for the membrane-inserted protein. however, ba ... | 2006 | 16385471 |
| vegetative insecticidal protein (vip1ac) of bacillus thuringiensis hd201: evidence for oligomer and channel formation. | the binding component (vip1ac) of the adp-ribosylating vegetative insecticidal protein (vip) of bacillus thuringiensis hd201 was isolated from the supernatant of cell cultures. vip1ac protein solubilized at room temperature ran as oligomers on sds-page. these oligomers were not resistant to heating. mass spectroscopic analysis of this high molecular mass band identified it as vip1ac. the protein formed in artificial lipid bilayer membranes channels with two conductance states of about 350 and 70 ... | 2006 | 16388604 |
| influence of cry1ac toxin on mineralization and bioavailability of glyphosate in soil. | the impact of transgenic plants containing bacillus thuringiensis (bt) toxin on soil processes has received recent attention. in these studies, we examined the influence of the lepidopterean bt cry1ac toxin on mineralization and bioavailability of the herbicide glyphosate in two different soils. the addition of 0.25-1.0 microg g(-1) soil of purified cry1ac toxin did not significantly affect glyphosate mineralization and sorption in either a sandy loam or a sandy soil. in contrast, extractable gl ... | 2006 | 16390194 |
| a bacillus thuringiensis s-layer protein involved in toxicity against epilachna varivestis (coleoptera: coccinellidae). | the use of bacillus thuringiensis as a biopesticide is a viable alternative for insect control since the insecticidal cry proteins produced by these bacteria are highly specific; harmless to humans, vertebrates, and plants; and completely biodegradable. in addition to cry proteins, b. thuringiensis produces a number of extracellular compounds, including s-layer proteins (slp), that contribute to virulence. the s layer is an ordered structure representing a proteinaceous paracrystalline array whi ... | 2006 | 16391064 |
| use of bacillus thuringiensis toxins for control of the cotton pest earias insulana (boisd.) (lepidoptera: noctuidae). | thirteen of the most common lepidopteran-specific cry proteins of bacillus thuringiensis have been tested for their efficacy against newly hatched larvae of two populations of the spiny bollworm, earias insulana. at a concentration of 100 microg of toxin per milliliter of artificial diet, six cry toxins (cry1ca, cry1ea, cry1fa, cry1ja, cry2aa, and cry2ab) were not toxic at all. cry1aa, cry1ja, and cry2aa did not cause mortality but caused significant inhibition of growth. the other cry toxins (c ... | 2006 | 16391075 |
| protease inhibitors fail to prevent pore formation by the activated bacillus thuringiensis toxin cry1aa in insect brush border membrane vesicles. | to investigate whether membrane proteases are involved in the activity of bacillus thuringiensis insecticidal toxins, the rate of pore formation by trypsin-activated cry1aa was monitored in the presence of a variety of protease inhibitors with manduca sexta midgut brush border membrane vesicles and by a light-scattering assay. most of the inhibitors tested had no effect on the pore-forming ability of the toxin. however, phenylmethylsulfonyl fluoride, a serine protease inhibitor, promoted pore fo ... | 2006 | 16391085 |
| role of tryptophan residues in toxicity of cry1ab toxin from bacillus thuringiensis. | bacillus thuringiensis produces insecticidal proteins (cry protoxins) during the sporulation phase as parasporal crystals. during intoxication, the cry protoxins must change from insoluble crystals into membrane-inserted toxins which form ionic pores. the structural changes of cry toxins during oligomerization and insertion into the membrane are still unknown. the cry1ab toxin has nine tryptophan residues; seven are located in domain i, the pore-forming domain, and two are located in domain ii, ... | 2006 | 16391132 |
| detection and identification of cry1i genes in bacillus thuringiensis using polymerase chain reaction and restriction fragment length polymorphism analysis. | a polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) method for detection and identification of cry1i genes from bacillus thuringiensis (bt) was established. based on the analysis of conserved regions of the cry1i genes, 2 oligonucleotide primers were designed to amplify a 665-bp fragment of the genes. the amplification products were digested with restriction endonuclease hinfi or with rsai in addition for specific detection of different variants from the known subclas ... | 2006 | 16392002 |
| nontoxic crystal protein from bacillus thuringiensis demonstrates a remarkable structural similarity to beta-pore-forming toxins. | 2006 | 16400649 | |
| transgenic crops expressing bacillus thuringiensis toxins and biological control. | the area devoted to growing transgenic plants expressing insecticidal cry proteins derived from bacillus thuringiensis (bt) is increasing worldwide. a major concern with the adoption of bt crops is their potential impact on nontarget organisms including biological control organisms. regulatory frameworks should advocate a step-wise (tiered) approach to assess possible nontarget effects of bt crops. laboratory and glasshouse studies have revealed effects on natural enemies only when bt-susceptibl ... | 2006 | 16404399 |
| mass spectrometric sequencing of endotoxin proteins of bacillus thuringiensis ssp. konkukian extracted from polyacrylamide gels. | the amino acid sequences of the crystal proteins of bacillus thuringiensis ssp. konkukian strain hl-47 are unknown. we used 1-d denaturing polyacrylamide electrophoresis, nano-esi-q-tof-ms, and protein database searching to analyze these proteins. on sds-page gels, a preparation of purified crystal proteins exhibited 110, 102, 76, 55, 37, and 30 kda protein bands. immunoblotting of the gel with antiserum raised to this preparation revealed that four crystal proteins, of 110, 102, 55, and 37 kda, ... | 2006 | 16404726 |
| a novel index for analysing the response of a microbial culture to changes in the environmental variables during cultivation. | to analyse the sensitivity of a microbial culture to variations in the cultivation conditions by using the motile intensity of the cells. | 2006 | 16405701 |
| lack of cross-reactivity between the bacillus thuringiensis derived protein cry1f in maize grain and dust mite der p7 protein with human sera positive for der p7-ige. | cry1f protein, derived from bacillus thuringiensis, is effective at controlling lepidopteran pests and a synthetic cry1f transgene was transferred into maize. for the safety assessment of genetically modified food crops, the allergenic potential of the introduced novel trait(s) is evaluated. because no single parameter is currently predictive of allergic potential, a 'weight of evidence' approach has been proposed. as part of this assessment, the amino acid (aa) sequence of the cry1f protein was ... | 2006 | 16406630 |
| effect of bacillus thuringiensis subsp. israelensis and neonicotinoid insecticides on the fungus gnat bradysia sp nr. coprophila (lintner) (diptera: sciaridae). | the soil bacterium bacillus thuringiensis berliner subsp. israelensis (bti), the neonicotinoid insecticides dinotefuran, imidacloprid, thiamethoxam and clothianidin and the insect growth regulator pyriproxyfen were evaluated to determine their efficacy against the larval stages of the fungus gnat bradysia sp nr. coprophila (lintner) in the laboratory. treatments were applied as a drench to the growing medium in polypropylene deli containers. the bti treatments had no effect on either instar test ... | 2006 | 16408320 |
| regeneration of sugarcane elite breeding lines and engineering of stem borer resistance. | five elite sugarcane breeding lines were tested for efficiency in embryogenesis and plant regeneration. all of them produced regenerative embryogenic calli but with varied efficiencies. to engineer strongly insect-resistant sugarcanes, the gc content of a truncated cry1ac gene, which encodes the active region of cry1ac insecticidal delta-endotoxin, was increased from the original 37.4 to 47.5% following the sugarcane codon usage pattern. the synthetic cry1ac gene (s-cry1ac) was placed under the ... | 2006 | 16408322 |
| a new black fly isolate of bacillus thuringiensis autoagglutinating strain highly toxic to simulium pertinax (kollar) (diptera, simuliidae) larvae. | formulations containing the entomopathogenic bacillus thuringiensis serovar israelensis strain ips-82 has been widely applied for mosquito control around the world. strain ips-82 is highly active against aedes aegypti but less active against other well-known vectors such as culex quinquefasciatus and simulium spp. larvae. eighteen strains of b. thuringiensis were isolated from simulium pertinax larvae naturally occurring in rivers of southeast brazil with one demonstrating special toxic effects. ... | 2006 | 16410971 |
| evidence of oral toxicity of photorhabdus temperata strain k122 against prays oleae and its improvement by heterologous expression of bacillus thuringiensis cry1aa and cry1ia genes. | photorhabdus temperata strain k122 exhibited oral toxicity against prays oleae with an lc50 of 58.1 x 10(6) cells ml(-1). recombinant p. temperata strains expressing the cry1aa and/or cry1ia genes of bacillus thuringiensis have been constructed. the two cry genes, encoding delta-endotoxins, were placed under the control of the lac promoter and iptg dependent expression in p. temperata was demonstrated. the presence of the cry genes in k122 resulted in a clear improvement of oral toxicity. this i ... | 2006 | 16413572 |
| method modification (2004.08) to field testing of visible powders on a variety of nonporous environmental surfaces: field study. | the ramp anthrax test cartridge for detecting bacillus anthracis was validated for use in the field for detection of b. anthracis spores in visible powder residues on 7 nonporous environmental surfaces. six teams of trained first responders and civil support personnel in class c personal protective equipment sampled visible powder residues on plastic, stainless steel, ceramic tile, wood, rubber, sealed concrete, and food-grade painted wood and analyzed the samples on the ramp anthrax test system ... | 2006 | 17225611 |
| cadherin-based resistance to bacillus thuringiensis cotton in hybrid strains of pink bollworm: fitness costs and incomplete resistance. | recessive resistance to bacillus thuringiensis (bt) cotton, gossypium hirsutum l., in laboratory-selected strains of pink bollworm, pectinophora gossypiella (saunders), is associated with three resistance alleles (r1, r2, and r3) of a cadherin gene. previous experiments based on measurement of fitness components in bt-resistant and bt-susceptible strains revealed that fitness costs and incomplete resistance are associated with resistance. here, we used two hybrid strains of pink bollworm, each c ... | 2006 | 17195656 |
| interactions among white spruce tannins, bacillus thuringiensis subsp. kurstaki, and spruce budworm (lepidoptera: tortricidae), on larval survival, growth, and development. | the interactions among white spruce, picea glauca (moench) voss, purified acetone tannin extracts (hydrolyzable and condensed tannin), bacillus thuringiensis subsp. kurstaki cry1a(c) delta-endotoxin strain hd-73 (btk), and spruce budworm, choristoneura fumiferana (clemens) (lepidoptera: tortricidae) on larval survival, growth, and development were investigated over the whole larval feeding period by using artificial diet supplemented with three concentrations of btk toxins per milliliter of diet ... | 2006 | 17195671 |
| impact of small fitness costs on pest adaptation to crop varieties with multiple toxins: a heuristic model. | a deterministic two-locus model was used to examine how small fitness costs to individuals carrying resistance alleles could impact the risk of panmictic insect pest populations adapting to crop varieties that produced two distinct toxins. parameters examined were (1) level of toxicity of each toxin, (2) initial frequencies of alleles for adaptation to the toxins, (3) percentage of population feeding on nontoxic plants, and (4) level of fitness cost associated with adaptation to each of the two ... | 2006 | 17195678 |
| modeling the impact of alternative hosts on helicoverpa zea adaptation to bollgard cotton. | for highly polyphagous cotton, gossypium hirsutum l., pests such as helicoverpa zea (boddie), a substantial portion of the larval population develops on noncotton alternative hosts. these noncotton hosts potentially provide a natural refuge for h. zea, thereby slowing the evolution of resistance to the bacillus thuringiensis berliner (bt)-derived cry1ac protein present in bollgard cotton. here, we demonstrate how the measured contribution of such alternative hosts can be included in estimating t ... | 2006 | 17195681 |
| high-level resistance to bacillus thuringiensis toxin crylac and cadherin genotype in pink bollworm. | resistance to transgenic cotton, gossypium hirsutum l., producing bacillus thuringiensis (bt) toxin cry1ac is linked with three recessive alleles of a cadherin gene in laboratory-selected strains of pink bollworm, pectinophora gossypiella (saunders), a major cotton pest. here, we analyzed a strain (mov97-r) with a high frequency of cadherin resistance alleles, a high frequency of resistance to 10 microg of cry1ac per milliliter of diet, and an intermediate frequency of resistance to 1000 microg ... | 2006 | 17195682 |
| decreased whorl and ear damage in nine mon810 bacillus thuringiensis (bt)-transgenic corn hybrids compared with their non-bt counterparts. | we examined nine pairs of near-isogenic hybrids of bacillus thuringiensis (bt) and non-bt corn, zea mays l., at two locations in 1999 and three locations in 2000 to compare the effects of bt toxins on damage caused by helicoverpa zea (boddie) to whorl stage field corn, and ear damage at harvest, as well as yield. we found that whorl damage was less in all bt hybrids compared with their non-bt counterparts each year and at each location. differences in ear damage between bt and non-bt hybrids, ho ... | 2006 | 17195689 |
| [adjuvant effect of the cry1ac protoxin on cellular immunity when is coadministered with a good mucosal pathogen]. | the major part of pathogens use the mucosae to penetrate into the organisms, the idea to blockade the invasion, replication, colonization and multiplication of them results attractive not only to vaccines design, but immunopharmacs design, too. the protoxin cry1ac from bacillus thuringiensis is a recent known mucosal adjuvant. | 2006 | 17137187 |
| organic mystery. pesticide may not really be an insect killer. | 2006 | 17144343 | |
| fees or refuges: which is better for the sustainable management of insect resistance to transgenic bt corn? | the evolution of resistance in insect pests will imperil the efficiency of transgenic insect-resistant crops. the currently advised strategy to delay resistance evolution is to plant non-toxic crops (refuges) in close proximity to plants engineered to express the toxic protein of the bacterium bacillus thuringiensis (bt). we seek answers to the question of how to induce growers to plant non-toxic crops. a first strategy, applied in the united states, is to require bt growers to plant non-bt refu ... | 2006 | 17148361 |
| investigation of a novel bacillus thuringiensis gene encoding a parasporal protein, parasporin-4, that preferentially kills human leukemic t cells. | a novel gene encoding a leukemic cell-killing parasporal protein, designated parasporin-4, was cloned from an isolate of bacillus thuringiensis serovar shandongiensis. the amino acid sequence of the parasporin-4, as deduced from the gene sequence, had low-level homologies of <30% with the established b. thuringiensis cry proteins including the three known parasporins. when the gene was expressed in a recombinant of escherichia coli bl21(de3), the parasporin-4 formed intracellular inclusion bodie ... | 2006 | 17151476 |
| use of bacillus thuringiensis toxin as an alternative method of control against haemonchus contortus. | the biocide activity of bacillus thuringiensis (b. thuringiensis) ib-16 strain was evaluated against the blood-feeding nematode haemonchus contortus (h. contortus) in vitro and in vivo assays. twenty experimental jirds (meriones unguiculatus) and 32 sheep were infected with h. contortus by oral route. fourteen days post infection 10 jirds were treated with 0.2 mg per ml of ib-16 soluble toxin by intraperitoneal (i.p.) route and 8 sheep were treated with 0.5 mg of toxin per kg of body weight by i ... | 2006 | 17135537 |
| status of eldana saccharina (lepidoptera: pyralidae), its host plants and natural enemies in ethiopia. | surveys for sugarcane stem borers were undertaken in ethiopia to determine the prevalence and distribution of these and their natural enemies in crops and indigenous host plants. eldana saccharina walker was not recovered from sugarcane, but was present in three indigenous wetland sedges, cyperus papyrus, c. fastigiatus and c. dives in the southern, central and northern part of the country. the latter indigenous host plant was present in waterways adjacent to sugarcane on the commercial sugar es ... | 2006 | 17092361 |
| caenorhabditis elegans carbohydrates in bacterial toxin resistance. | the major virulence factor produced by the bacterium bacillus thuringiensis (bt) is a pore-forming toxin called crystal (cry) toxin, which targets and kills insects and nematodes. to understand how this bacterial toxin interacts with its invertebrate hosts, a genetic screen in c. elegans for nematodes resistant to bt toxin was carried out. four of the five genes that mutated to toxin resistance encode glycosyltransferases. these genes were found to participate in the biosynthesis of c. elegans g ... | 2006 | 17132513 |
| identification and characterization of a polysaccharide deacetylase gene from bacillus thuringiensis. | one polysaccharide deacetylase gene was cloned from bacillus thuringiensis and designated pdaa. disruption of pdaa did not affect vegetative growth and sporulation but obviously affected spore germination. when l-alanine was added into the spore suspension, the spores of the pdaa disruption mutant showed a slow and partial reduction in absorbance at od600 and became phase pale gray compared with phase dark of the wild-type strain. in contrast with the outgrowing of wild-type spores after germina ... | 2006 | 17110961 |
| [characterization of crystal-forming bacteria bacillus thuringiensis subsp. tohokuensis toxic to mosquitos]. | distribution study of bacillus thuringiensis strains in western siberian soils allowed us to isolate crystal-forming bacteria assigned to a new pathovar of bacillus thuringiensis ssp. tohokuensis with a toxic effect on mosquito larvae. a description of this bacterial pathovar is presented. | 2006 | 17086974 |
| effects of disulfide bridges in domain i of bacillus thuringiensis cry1aa delta-endotoxin on ion-channel formation in biological membranes. | the delta-endotoxin family of toxic proteins represents the major component of the insecticidal capability of the bacterium bacillus thuringiensis. domain i of the toxins, which is largely alpha-helical, has been proposed to unfold at protein entry into the membrane of a target insect, following models known as the penknife and umbrella models. we extended the analysis of a previous work in which four disulfide bridges were constructed in domain i of the cry1aa delta-endotoxin that putatively pr ... | 2006 | 17087513 |
| persistence of bacillus thuringiensis bioinsecticides in the gut of human-flora-associated rats. | the capability of two bioinsecticide strains of bacillus thuringiensis (ssp. israelensis and ssp. kurstaki) to germinate and persist in vivo in the gastrointestinal tract of human-flora-associated rats was studied. rats were dosed either with vegetative cells or spores of the bacteria for 4 consecutive days. in animals fed spores, b. thuringiensis cells were detected in faecal and intestinal samples of all animals, whereas vegetative cells only poorly survived the gastric passage. heat-treatment ... | 2006 | 17087815 |
| an indigenous drought-tolerant strain of glomus intraradices associated with a native bacterium improves water transport and root development in retama sphaerocarpa. | the effects of interactions between bacillus thuringiensis, a drought-adapted bacterium, and two isolates of glomus intraradices, an arbuscular mycorrhizal (am) fungus, on retama sphaerocarpa, a drought-adapted legume, were investigated. the fungal isolates were an indigenous drought-tolerant and a nonindigenous drought-sensitive isolate. shoot length and root growth, symbiotic parameters, water transport (in terms of percent relative plant water uptake), and volumetric soil moisture and soil en ... | 2006 | 17075734 |
| the quorum-quenching metallo-gamma-lactonase from bacillus thuringiensis exhibits a leaving group thio effect. | lactone-hydrolyzing enzymes derived from some bacillus species are capable of disrupting quorum sensing in bacteria that use n-acyl-l-homoserine lactones (ahls) as intercellular signaling molecules. despite the promise of these quorum-quenching enzymes as therapeutic and anti-biofouling agents, the ring opening mechanism and the role of metal ions in catalysis have not been elucidated. labeling studies using (18)o, (2)h, and the ahl lactonase from bacillus thuringiensis implicate an addition-eli ... | 2006 | 17073460 |
| field evaluation of bacillus thuringiensis h-14 against aedes mosquitoes. | studies were carried out on the residual efficacy of bacillus thuringiensis h-14 (water dispersible granule, vectobac abg 6511) as direct application in the control of aedes larvae in the field. field aedes sp populations in the earthen and glass jars were predetermined before initiation of the trial. on confirmation of the presence of aedes species in the designated area, sungai nibong kecil, penang island, malaysia, bti was introduced in the 55l earthen and 3l glass jars). two test designs wer ... | 2006 | 17041550 |
| assays for toxicity studies in c. elegans with bt crystal proteins. | caenorhabditis elegans is well suited for toxicological studies owing to its established biology, short generation time, large brood size, and readily scorable life traits. quantitative parameters of c. elegans that can be assayed include growth, size, progeny production, behavior, and mortality. qualitative parameters of toxicity, such as changes in appearance or movement, can also be determined. this chapter describes four assays we have used for analyzing the toxic effects of bacillus thuring ... | 2006 | 16988432 |
| suppression of exposure to malaria vectors by an order of magnitude using microbial larvicides in rural kenya. | to determine the contribution larviciding could make to reduce the burden of malaria, by conducting a trial of microbial larvicides in a 4.5 km2 area in and around a large village in rural western kenya. | 2006 | 17054742 |
| molecular characterization of a dna fragment harboring the replicon of pbmb165 from bacillus thuringiensis subsp. tenebrionis. | bacillus thuringiensis belongs to the bacillus cereus sensu lato group of gram-positive and spore-forming bacteria. most isolates of b. thuringiensis can bear many endogenous plasmids, and the number and size of these plasmids can vary widely among strains or subspecies. as far as we know, the replicon of the plasmid pbmb165 is the first instance of a plasmid replicon being isolated from subsp. tenebrionis and characterized. | 2006 | 17059605 |
| dna screening reveals pink bollworm resistance to bt cotton remains rare after a decade of exposure. | transgenic crops producing toxins from the bacterium bacillus thuringiensis (bt) kill insect pests and can reduce reliance on insecticide sprays. although bt cotton (gossypium hirsutum l.) and bt corn (zea mays l.) covered 26 million ha worldwide in 2005, their success could be cut short by evolution of pest resistance. monitoring the early phases of pest resistance to bt crops is crucial, but it has been extremely difficult because bioassays usually cannot detect heterozygotes harboring one all ... | 2006 | 17066779 |
| integrating biological and chemical controls in decision making: european corn borer (lepidoptera: crambidae) control in sweet corn as an example. | as growers switch to transgenic crops and selective insecticides that are less toxic to natural enemies, natural enemies can become more important in agricultural pest management. current decision-making guides are generally based on pest abundance and do not address pest and natural enemy toxicity differences among insecticides or the impact of natural enemies on pest survival. a refined approach to making pest management decisions is to include the impact of natural enemies and insecticides, t ... | 2006 | 17066781 |