Publications
Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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a qtl that enhances and broadens bt insect resistance in soybean. | effective strategies are needed to manage insect resistance to bacillus thuringiensis (bt) proteins expressed in transgenic crops. to evaluate a multiple resistance gene pyramiding strategy, eight soybean (glycine max) lines possessing factorial combinations of two quantitative trait loci (qtls) from plant introduction (pi) 229358 and a synthetic bt cry1ac gene were developed using marker-assisted selection with simple sequence repeat markers. field studies were conducted in 2000 and 2001 to eva ... | 2004 | 15243707 |
a simple, rapid, high-fidelity and cost-effective pcr-based two-step dna synthesis method for long gene sequences. | chemical synthesis of dna sequences provides a powerful tool for modifying genes and for studying gene function, structure and expression. here, we report a simple, high-fidelity and cost-effective pcr-based two-step dna synthesis (ptds) method for synthesis of long segments of dna. the method involves two steps. (i) synthesis of individual fragments of the dna of interest: ten to twelve 60mer oligonucleotides with 20 bp overlap are mixed and a pcr reaction is carried out with high-fidelity dna ... | 2004 | 15240836 |
improvement of bioinsecticides production through mutagenesis of bacillus thuringiensis by u.v. and nitrous acid affecting metabolic pathways and/or delta-endotoxin synthesis. | the present work aimed to obtain bioinsecticide over-producing mutants through classical mutagenesis of vegetative cells of bacillus thuringiensis (bt) by using u.v. and nitrous acid, and to evidence the involvement of cell metabolism in delta-endotoxin synthesis. | 2004 | 15239700 |
susceptibility of the leaf-eating beetle, galerucella calmariensis, a biological control agent for purple loosestrife (lythrum salcaria), to three mosquito control larvicides. | we evaluated the susceptibility of galerucella calmariensis, a species used to control purple loosestrife (lythrum salicaria), to three mosquito control larvicides. larvae and adults were fed loosestrife cuttings dipped in abate (< or = 375 g x l(-1)), altosid (< or = 250 g x l(-1)), and bacillus thuringiensis var israeliensis (bti) (< or = 110 g x l(-1)). eggs on cuttings were dipped in the same concentrations. pupae were immersed in abate and altosid solutions (< or = 474.4 microg x l(-1) and ... | 2004 | 15230319 |
is231-mic231 elements from bacillus cereus sensu lato are modular. | summary is231a was originally discovered in bacillus thuringiensis as a typical 1.6 kb insertion sequence (is) displaying 20 bp inverted repeats (ir) flanking a transposase gene. a first major variation of this canonical organization was found in mic231a1. this mobile insertion cassette (mic), delineated by is231a-related extremities, contained an active d-stereospecific endopeptidase (adp) gene instead of a transposase. interestingly, it was shown that mic231a1 can be mobilized in trans by the ... | 2004 | 15228527 |
soil microbial communities associated with bt and non-bt corn in three soils. | the effects of expression of cry endotoxin by bt corn (transgenic corn engineered to express bacillus thuringiensis toxin) on soil microbial community structure were assessed in a growth chamber experiment. two lines of transgenic corn expressing different cry endotoxins were compared with their respective non-transgenic isolines in three soil types with differing textures. phospholipid fatty acid (plfa) profiles from bulk soil and community-level physiological profiles (clpp) from the rhizosphe ... | 2004 | 15224917 |
development of stem borer resistant transgenic parental lines involved in the production of hybrid rice. | stem borer resistant transgenic parental lines, involved in hybrid rice, were produced by agrobacterium-mediated gene transfer method. two psb111 super-binary vectors containing modified cry1ab/cry1ac genes driven by maize ubiquitin promoter, and herbicide resistance gene bar driven by cauliflower mosaic virus 35s promoter were, used in this study. embryogenic calli after co-cultivation with agrobacterium were selected on the medium containing phosphinothricin. southern blot analyses of primary ... | 2004 | 15219400 |
melanin pigment formation and increased uv resistance in bacillus thuringiensis following high temperature induction. | the pigment melanin is well known to protect against the damaging effects of uv radiation. in this study, we show that thirty-five of thirty-seven tested bacillus thuringiensis strains possess the potential to produce melanin in the presence of l-tyrosin at elevated temperature (42 degrees c). these findings offer a method of protecting insecticidal toxins produced by b. thuringiensis from uv degredation and may therefore have important applications in the field of crop protection. toxicity assa ... | 2004 | 15214633 |
crystallization and preliminary crystallographic study of the functional form of the bacillus thuringiensis mosquito-larvicidal cry4aa mutant toxin. | the 65 kda functional form of the mosquito-larvicidal cry4aa-r235q mutant toxin has been crystallized. the crystals belong to space group c222(1), with unit-cell parameters a = 91.2, b = 202.1, c = 98.7 a, and contain one molecule per asymmetric unit. the crystals diffract to approximately 2.9 a using synchrotron radiation and a complete native data set has been collected. the structure has been solved using a molecular-replacement method with the cry4ba toxin protein as a search model. | 2004 | 15213403 |
composition of grain and forage from corn rootworm-protected corn event mon 863 is equivalent to that of conventional corn (zea mays l.). | insect-protected corn hybrids containing event mon 863 protect corn plants against feeding damage from corn rootworm (diabrotica), a major north american insect pest. corn event mon 863 contains a gene that expresses an amino acid sequence variant of the wild-type cry3bb1 insecticidal protein from bacillus thuringiensis. the purpose of this study was to compare the composition of corn containing event mon 863 with that of conventional nontransgenic corn. compositional analyses were conducted to ... | 2004 | 15212462 |
studies on cultured and uncultured microbiota of wild culex quinquefasciatus mosquito midgut based on 16s ribosomal rna gene analysis. | to describe the midgut microbial diversity and the candidate bacteria for the genetic manipulation for the generation of transgenic mosquitoes refractory to transmission of diseases, the microbiota of wild culex quinquefasciatus mosquito midgut was studied using a conventional culture technique and analysis of a 16s ribosomal rna (rrna) gene sequence library. the culturable microbiota was identified as acinetobacter junii, ac. calcoaceticus, aeromonas culicicola, bacillus thuringiensis, microbac ... | 2004 | 15210998 |
the injection of plasmid dna in mouse muscle results in lifelong persistence of dna, gene expression, and humoral response. | the duration of the immune response against any vaccine is critical. the present study was performed to determine the stability of injected plasmid deoxyribonucleic acid (dna), the duration of gene expression in mouse muscle, as well as the duration of the immune response generated in mice after injection of plasmid pso2c1 harboring the cry11bb gene of bacillus thuringiensis serovar. medellin. the localization and the persistence of the inoculated gene were determined by in situ hybridization an ... | 2004 | 15208453 |
effect of specific mutations in helix alpha7 of domain i on the stability and crystallization of cry3a in bacillus thuringiensis. | insecticidal crystal (cry) proteins of bacillus thuringiensis crystallize after synthesis forming large inclusions that stabilize these toxins in the environment after cell lysis until eaten by an insect. despite the biological importance of crystallization, little is known about the structural elements of cry molecules that facilitate this process. we identified subdomains that affect cry3a structure possibly through improper folding by chimeric-scanning mutagenesis, substituting short peptides ... | 2004 | 15208451 |
genetically modified foods get bad rap. | 2004 | 15204724 | |
molecular cloning and sequence analysis of the chitinase gene from bacillus thuringiensis serovar alesti. | endogenous chitinase plays a positive role in the pathogenicity of bacillus thuringiensis to insect pests. the chitinase gene was cloned from b. thuringiensis serovar alesti strain hd-16, and the deduced 676 amino acid sequence showed a high degree of similarity with other bacillus chitinases. additionally, the deduced amino acid sequence showed that the protein contained an amino terminus signal peptide and consisted of a catalytic domain, a fibronectin type iii domain and a chitin-binding doma ... | 2004 | 15200172 |
larvicidal cry proteins from bacillus thuringiensis are released in root exudates of transgenic b. thuringiensis corn, potato, and rice but not of b. thuringiensis canola, cotton, and tobacco. | larvicidal proteins encoded by cry genes from bacillus thuringiensis were released in root exudates from transgenic b. thuringiensis corn, rice, and potato but not from b. thuringiensis canola, cotton, and tobacco. nonsterile soil and sterile hydroponic solution in which b. thuringiensis corn, rice, or potato had been grown were immunologically positive for the presence of the cry proteins; from b. thuringiensis corn and rice, the soil and solution were toxic to the larva of the tobacco hornworm ... | 2004 | 15191740 |
bacillus thuringiensis serovar shandongiensis strain 89-t-34-22 produces multiple cytotoxic proteins with similar molecular masses against human cancer cells. | to prove that bacillus thuringiensis serovar shandongiensis strain 89-t-34-22 produces several novel cytotoxic proteins against human leukaemic t cells. | 2004 | 15189293 |
the autolytic phenotype of bacillus thuringiensis. | to evaluate the autolytic phenotype of bacillus thuringiensis. | 2004 | 15186453 |
laboratory selection for resistance to bacillus thuringiensis subsp. jegathesan or a component toxin, cry11b, in culex quinquefasciatus (diptera: culicidae). | the bacteria bacillus thuringiensis subsp. israelensis and bacillus sphaericus produce insecticidal toxins used to control mosquito larvae throughout the world. unfortunately, there are few alternative insecticides with similar activity and environmental safety, which may limit the long-term success of these insecticides. bacillus thuringiensis subsp. jegathesan is another bacterium with toxins that are active against mosquitoes and has potential for development as a commercial product. b. t. su ... | 2004 | 15185947 |
laboratory and simulated field evaluation of a new recombinant of bacillus thuringiensis ssp. israelensis and bacillus sphaericus against culex mosquito larvae (diptera: culicidae). | in the laboratory, three microbial mosquito larvicidal products consisting of bacillus thuringiensis ssp. israelensis de barjac (bti), bacillus sphaericus (neide) (bsph) (strain 2362), and the university of california riverside (ucr) recombinant (producing toxins of both bacillus sphaericus and bacillus thuringiensis ssp. israelensis) were bioassayed against larvae of culex quinequefasciatus say (susceptible and resistant to bsph 2362), and aedes aegypti (l.). bti proved highly effective against ... | 2004 | 15185945 |
insecticide resistance and cross-resistance in alabama and florida strains of culex quinquefasciatus [correction]. | insecticide resistance and cross-resistance was determined for three strains of culex quinquefasciatus say in the southeastern united states. hamcq and mamcq strains were collected in 2002 from huntsville and mobile, al. the vbfmcq strain was collected in 1998 from vero beach, fl. vbfmcq, hamcq, and mamcq larvae showed resistance to permethrin with resistance ratios of 13, 100, and 940, respectively, compared with the susceptible s-lab strain. levels of resistance in hamcq and mamcq larvae were ... | 2004 | 15185942 |
enhancement of cry19aa mosquitocidal activity against aedes aegypti by mutations in the putative loop regions of domain ii. | improvements in the mosquitocidal activity of bacillus thuringiensis cry19aa were achieved by protein engineering of putative surface loop residues in domain ii through rational design. the improvement of aedes toxicity in cry19aa was 42,000-fold and did not affect its toxicity against anopheles or culex. | 2004 | 15184189 |
responses of nontarget lepidoptera to foray 48b bacillus thuringiensis var. kurstaki on vancouver island, british columbia, canada. | impacts of a gypsy moth (lymantria dispar) eradication program on native, nontarget lepidoptera were assessed in 1999, on southeastern vancouver island (bc, canada). the microbial insecticide bacillus thuringiensis var. kurstaki (btk) was applied aerially over two areas totalling 12,805 ha on may 8, may 19, and june 8, 1999, at a dosage of 50 billion international units in 4.0 l/ha. lepidoptera were collected from two host plant species: garry oak (quercus garryana) and common snowberry (symphor ... | 2004 | 15180383 |
microcalorimetric investigation on the growth model and the protein yield of bacillus thuringiensis. | a novel microcalorimetric technique based on the bacterial heat output was applied to evaluate the special growth model, the protein expression and the generation time of bacillus thuringiensis for the first time. the thermogenic curves of the aerobic metabolism of b. thuringiensis strains ybt-833, ybt-1520 and ybt-833-2-1 were determined by using an lkb-2277 bioactivity monitor. the analysis of the thermogenic curves indicated both the mutant strain and the wild-type strains followed the same l ... | 2004 | 15165757 |
achieving successful deployment of bt rice. | 2004 | 15165560 | |
qualitative and quantitative pcr methods for detection of three lines of genetically modified potatoes. | qualitative and quantitative polymerase chain reaction (pcr) methods have been developed for the detection of genetically modified (gm) potatoes. the combination of specific primers for amplification of the promoter region of cry3a gene, potato leafroll virus replicase gene, and potato virus y coat protein gene allows to identify each line of newleaf, newleaf y, and newleaf plus gm potatoes. multiplex pcr method was also established for the simple and rapid detection of the three lines of gm pot ... | 2004 | 15161181 |
isolation, geographical diversity and insecticidal activity of bacillus thuringiensis from soils in spain. | bacillus thuringiensis is a spore-forming bacterium showing the unusual ability to produce endogenous crystals during sporulation that are toxic for some pest insects. this work was performed to study the composition, ecological distribution and insecticidal activity of isolates of this entomopathogenic bacterium from the spanish territory. using a standard isolation method, b. thuringiensis was isolated from 115 out of 493 soil samples collected in the iberian peninsula and the canary and balea ... | 2004 | 15160608 |
effect of ph and ionic strength on the cytolytic toxin cyt1a: a fluorescence spectroscopy study. | cyt1a is a cytolytic toxin produced by bacillus thuringiensis var. israelensis. due to its toxicity in vivo against mosquitoes and black flies, it is used as an environmentally friendly insecticide, although its mode of action is not completely understood. the toxin is membrane-active, but its membrane-bound conformation is unknown. in the absence of direct structural data, fluorescence spectroscopy was used to obtain indirect information on cyt1a conformation changes in the environment mimickin ... | 2004 | 15158719 |
interaction between lactic acid bacteria and gastrointestinal nematodes of caprine origin. | to compare the level of parasitism with gastrointestinal nematodes in sheep and goats, several studies have been conducted. they have generally shown that goats were more infected than sheep, as they exhibited higher worm burdens and egg excretion. this difference between two host species has been attributed not only to a difference in feeding behavior, but also to a lesser ability of goats to develop resistance to trichostrongylate infection (in kids and lambs the greatest damage is observed fr ... | 2004 | 15156032 |
the catalytic role of aspartate in a short strong hydrogen bond of the asp274-his32 catalytic dyad in phosphatidylinositol-specific phospholipase c can be substituted by a chloride ion. | phosphatidylinositol-specific phospholipase c from bacillus thuringiensis catalyzes the cleavage of the phosphorus-oxygen bond in phosphatidylinositol. the focus of this work is to dissect the roles of the carboxylate side chain of asp(274) in the asp(274)-his(32) dyad, where a short strong hydrogen bond (sshb) was shown to exist based on nmr criteria. a regular hydrogen bond (hb) was observed in d274n, and no low field proton resonance was detected for d274e and d274a. comparison of the activit ... | 2004 | 15155721 |
development of a highly efficient system for assessing recombinant gene expression in plant cell suspensions via agrobacterium tumefaciens transformation. | a transient gene-expression system was developed and used to characterize promoter strength, to verify suitability of bacterial gene modifications for expression in plant cells, and to express active antibody molecules. the system is based on suspension tobacco cells transformed by agrobacterium in a transient way. conditions such as pre-culture of tobacco cells and the co-cultivation period were identified as determinants to achieve high expression levels. under established conditions the activ ... | 2004 | 15154849 |
a survey of hymenopteran parasitoids of forest macrolepidoptera in the central appalachians. | in 1995 and 1996, we conducted a study of the hymenopteran parasitoids of macrolepidopteran larvae in the george washington national forest (gwnf), augusta county, virginia, and the monongahela national forest (mnf), pocahontas county, west virginia. macrolepidopteran larvae were collected from canopy foliage and from under canvas bands placed around tree boles. a total of 115 macrolepidopteran species and 5,235 individual larvae were reared. forty-two percent (2,221) of the larvae were gypsy mo ... | 2004 | 15154467 |
damage loss assessment and control of the cereal leaf beetle (coleoptera: chrysomelidae) in winter wheat. | cereal leaf beetle, oulema melanopus (l.), invaded northern alabama and georgia more than a decade ago and since has become an economic pest of winter wheat and other cereal crops in the southeastern united states. a series of trials was conducted beginning in 1995 to determine optimal rate and timing of applications of selected foliar insecticides for managing cereal leaf beetle in soft red winter wheat. these trials, cage studies with larvae, and a manual defoliation experiment were used to pr ... | 2004 | 15154458 |
biological control of lobesia botrana (lepidoptera: tortricidae) larvae by using different formulations of bacillus thuringiensis in 11 vine cultivars under field conditions. | this work describes the results of an experiment that was conducted in the vineyard of the american farm school, thermi, thessaloniki greece, during 2001. its aim was to study the efficacy of two formulations of bacillus thuringiensis berliner (wettable powder and dust) to control the larvae of lobesia botrana denis & schiffermueler (lepidoptera: tortricidae). the experimental results showed that the two formulations of b. thuringiensis are significantly more effective than the control, the dust ... | 2004 | 15154453 |
assessment of experimental bt events against fall armyworm and corn earworm in field corn. | performance of experimental bacillus thuringiensis (bt) mon events alone and pyramided with mon810 were evaluated over 3 yr in georgia and alabama. ability of events to prevent whorl defoliation by the fall armyworm, spodoptera frugiperda (j. e. smith), and natural ear feeding damage by the corn earworm, helicoverpa zea (boddie) was assessed. in each year, near-isogenic hybrids with novel single transformation events and crosses pyramided with the mon810 event were compared with the standard sin ... | 2004 | 15154443 |
screening of the insecticidal activity of bacillus thuringiensis strains against lygus hesperus (hemiptera: miridae) nymphal population. | lygus hesperus knight (hemiptera: miridae) is an economically important insect pest controlled primarily by chemical pesticides. bacillus thuringiensis berliner is a gram-positive bacterium that has been developed for the control of some insect pests in the orders lepidoptera, coleoptera, and diptera. in this study, whole culture extracts of 94 b. thuringiensis strains from 83 serovars were added to an artificial diet and assayed against l. hesperus first and second instars. a total of five b. t ... | 2004 | 15154442 |
novel oligosaccharide side chains of the collagen-like region of bcla, the major glycoprotein of the bacillus anthracis exosporium. | spores of bacillus anthracis, the causative agent of anthrax, are enclosed by a prominent loose fitting layer called the exosporium. the exosporium consists of a basal layer and an external hairlike nap. the filaments of the nap are composed of a highly immunogenic glycoprotein called bcla, which has a long, central collagen-like region with multiple xxg repeats. most of the triplet repeats are ptg, and nearly all of the triplet repeats contain a threonine residue, providing multiple potential s ... | 2004 | 15152001 |
natural variation in the response of caenorhabditis elegans towards bacillus thuringiensis. | almost nothing is known about the natural ecology of the nematode caenorhabditis elegans, including its interactions with parasites. to help rectify this discrepancy, we assessed natural variation in the response of c. elegans towards a potential parasite, the soil bacterium bacillus thuringiensis. our results show that 10 isolates from across the world differ significantly in survival rate and infection level when confronted with a parasitic strain of b. thuringiensis. furthermore, behavioural ... | 2004 | 15151149 |
distinct mutations in plcr explain why some strains of the bacillus cereus group are nonhemolytic. | bacillus thuringiensis, bacillus cereus, and bacillus anthracis are closely related species belonging to the bacillus cereus group. b. thuringiensis and b. cereus generally produce extracellular proteins, including phospholipases and hemolysins. transcription of the genes encoding these factors is controlled by the pleiotropic regulator plcr. disruption of plcr in b. cereus and b. thuringiensis drastically reduces the hemolytic, lecithinase, and cytotoxic properties of these organisms. b. anthra ... | 2004 | 15150241 |
pore worms: using caenorhabditis elegans to study how bacterial toxins interact with their target host. | the interaction of pathogenic bacteria with a target host is regulated both by bacterial virulence factors and by host components that either protect the host or that promote pathogenesis. the soil nematode caenorhabditis elegans is a host for a number of bacterial pathogens, as briefly reviewed here. bacillus thuringiensis (bt) is a pathogenic bacteria that c. elegans is likely to encounter naturally in the soil. the pore-forming crystal (cry) toxins made by bt are recognized as the dominant vi ... | 2004 | 15149037 |
starlink genetically modified corn and allergenicity in an individual. | 2004 | 15148966 | |
characterization of mexican bacillus thuringiensis strains toxic for lepidopteran and coleopteran larvae. | bacillus thuringiensis strains c-4, c-9, gm-7, and gm-10, isolated from northeast mexico and selected for their high toxicity against lepidopteran and coleopteran pests, were characterized following united states environmental protection agency (epa)'s guidelines. flagellar serotyping revealed that gm-7 and gm-10 belonged to serotype aizawai, whereas c-4, c-9 corresponded to the kumamotoensis serotype. gm-10 and c-9 were also shown to be the most effective against lepidoptera and coleoptera larv ... | 2004 | 15145246 |
[techniques of diseases, insect pests and weeds control and their efficacy in bio-rational rice production]. | studies on the efficacy of bio-rational pesticides and agricultural methods against the chief diseases, insect pests and weeds of rice showed that the efficacy of the mixtures of jingangmycin and bacillus-cereus, and jingangmycin and polyoxin against rice sheath blight were 75.16%-94.27% after sprayed once at the tiller and boot end stages of rice, respectively, and better than that of chemical fungicide triadimefon. the efficacy of kasugamycin and blasticidin was 50.54%-72.67% on rice leaf blas ... | 2004 | 15139200 |
contamination of refuges by bacillus thuringiensis toxin genes from transgenic maize. | transgenic crops producing insecticidal toxins from bacillus thuringiensis (bt) are widely used to control pests, but their benefits will be lost if pests evolve resistance. the mandated high-dose/refuge strategy for delaying pest resistance requires planting refuges of toxin-free crops near bt crops to promote survival of susceptible pests. we report that pollen-mediated gene flow up to 31 m from bt maize caused low to moderate bt toxin levels in kernels of non-bt maize refuge plants. immunoass ... | 2004 | 15136739 |
optimised expression in escherichia coli and purification of the functional form of the bacillus thuringiensis cry4aa delta-endotoxin. | achieving high-level expression of the bacillus thuringiensis cry4aa mosquito-larvicidal protein was demonstrated. the 130-kda cry4aa protoxin was overexpressed as an inclusion body in escherichia coli under the control of the tac promoter together with the cry4ba promoter. the solubility of the toxin inclusions in carbonate buffer, ph 10.0, was markedly enhanced at a cultivation temperature of 30 degrees c. elimination of the tryptic cleavage site at arg-235 in the loop between helices 5 and 6 ... | 2004 | 15135419 |
the drosophila melanogaster homologue of the human histo-blood group pk gene encodes a glycolipid-modifying alpha1,4-n-acetylgalactosaminyltransferase. | insects express arthro-series glycosphingolipids, which contain an alpha1,4-linked galnac residue. to determine the genetic basis for this linkage, we cloned a cdna (cg17223) from drosophila melanogaster encoding a protein with homology to mammalian alpha1,4-glycosyltransferases and expressed it in the yeast pichia pastoris. culture supernatants from the transformed yeast were found to display a novel udp-galnac:galnacbeta1,4glcnacbeta1-r alpha-n-acetylgalactosaminyltransferase activity when usi ... | 2004 | 15130086 |
low-level detection of a bacillus anthracis simulant using love-wave biosensors on 36 degrees yx litao3. | we present an acoustic love-wave biosensor for detection of the bacillus anthracis simulant, bacillus thuringiensis at or below inhalational infectious levels. the present work is an experimental study of 36 degrees yx cut litao3 based love-wave devices for detection of pathogenic spores in aqueous conditions. given that the detection limit (d1) of love-wave-based sensors is a strong function of the overlying waveguide, two waveguide materials have been investigated, which are polyimide and poly ... | 2004 | 15128104 |
an extracytoplasmic-function sigma factor is involved in a pathway controlling beta-exotoxin i production in bacillus thuringiensis subsp. thuringiensis strain 407-1. | beta-exotoxin i is an insecticidal nucleotide analogue secreted by various bacillus thuringiensis strains. in this report, we describe the characterization and transcriptional analysis of a gene cluster, designated sigw-ecfx-ecfy, that is essential for beta-exotoxin i production in b. thuringiensis subsp. thuringiensis strain 407-1. in this strain, the disruption of the sigw cluster resulted in nontoxic culture supernatants. sigw encodes a protein of 177 residues that is 97 and 94% identical to ... | 2004 | 15126472 |
bt-r1a extracellular cadherin repeat 12 mediates bacillus thuringiensis cry1ab binding and cytotoxicity. | the cadherin protein bt-r(1a) is a receptor for bacillus thuringiensis cry1a toxins in manduca sexta. cry1ab toxin is reported to bind specific epitopes located in extracellular cadherin repeat (cr) 7 and cr11 on bt-r(1) (gomez, b., miranda-rios, j., riudino-pinera, e., oltean, d. i., gill, s. s., bravo, a., and soberon, m. (2002) j. biol. chem. 277, 30137-30143; dorsch, j. a., candas, m., griko, n., maaty, w., midboe, e., vadlamudi, r., and bulla, l. (2002) insect biochem. mol. biol. 32, 1025-1 ... | 2004 | 15123702 |
effects of bt plants on the development and survival of the parasitoid cotesia plutellae (hymenoptera: braconidae) in susceptible and bt-resistant larvae of the diamondback moth, plutella xylostella (lepidoptera: plutellidae). | a range of crops have been transformed with delta-endotoxin genes from bacillus thuringiensis (bt) to produce transgenic plants with high levels of resistance to lepidopteran pests. parasitoids are important natural enemies of lepidopteran larvae and the effects of bt plants on these non-target insects have to be investigated to avoid unnecessary disruption of biological control. this study investigated the effects of cry1ac-expressing transgenic oilseed rape (brassica napus) on the solitary bra ... | 2004 | 15121457 |
biolarvicides in vector control: challenges and prospects. | biolarvicides, based on mosquitocidal toxins of certain strains of bacillus sphaericus and bacillus thuringiensis var israelensis h-14 (bti) are highly effective against mosquito larvae at very low doses and safe to other non-target organisms. during past two decades various biolarvicide formulations produced in india and abroad have been tested at malaria research centre and some formulations have undergone large-scale operational trials. biolarvicide formulations of b. sphaericus are useful in ... | 2003 | 15119068 |
bacterial insecticidal toxins. | over the years it has been important for humans to control the populations of harmful insects and insecticides have been used for this purpose in agricultural and horticultural sectors. synthetic insecticides, owing to their various side effects, have been widely replaced by biological insecticides. in this review we attempt to describe three bacterial species that are known to produce insecticidal toxins of tremendous biotechnological, agricultural, and economic importance. bacillus thuringiens ... | 2004 | 15116762 |
chitosanase activity in bacillus thuringiensis. | the ability to produce extracellular chitosanase (ec 3.2.1.132) was found by plate assays in 18 (23%) out of 77 crystalliferous strains of bacillus thuringiensis. the best chitosanase producer was selected after the growth chosen in a liquid medium with colloidal chitosan as carbon source. enzyme production was optimized (a 4-d incubation at 32 degrees c with shaking in a medium of ph 6.5 with 4% colloidal chitosan) and the enzyme was partially characterized. this is the first report on the chit ... | 2004 | 15114873 |
compositional equivalency of cry1f corn event tc6275 and conventional corn (zea mays l.). | maize (zea mays l.) plants have been transformed to express a cry1f insecticidal crystal protein originally isolated from bacillus thuringiensis berliner. this protein controls lepidopteran pests of maize, including the european corn borer, ostrinia nubilalis (hübner). as part of the safety assessment for crops containing transgenes, a compositional analysis of the food and feed is conducted. this analysis is designed to detect unintended changes in the nutrient and antinutrient content of the r ... | 2004 | 15113183 |
bioprocess design and economic analysis for the commercial production of environmentally friendly bioinsecticides from bacillus thuringiensis hd-1 kurstaki. | a production process for b. thuringiensis (bt) bioinsecticides was designed in detail, including alternative batch, low-density fed-batch (ldfb), and high-density fed-batch (hdfb) fermentation configurations. capital and operating costs, as well as profitability based on simple rate of return, were performed using a purpose-written fortran program, explicitly analyzing production of a water-based flowable product used in forestry applications. the total capital cost was 18 million dollars (canad ... | 2004 | 15112290 |
phospholipid molecular species profiles of tectiviruses infecting gram-negative and gram-positive hosts. | the phospholipid (pl) molecular species compositions of bacteriophages prd1 and bam35 as well as their respective hosts were determined quantitatively using liquid chromatography/electrospray ionization mass-spectrometry (lc-esi-ms) and backed up by gas-chromatographic/mass-spectrometric (gc-ms) analysis of the total fatty acids (fas). the results showed that both viruses contain significantly more phosphatidylglycerol (pg) and less phosphatidylethanolamine (pe) than the host membranes. only mod ... | 2004 | 15110530 |
lyophilization of lepidopteran midguts: a preserving method for bacillus thuringiensis toxin binding studies. | binding assays with brush border membrane vesicles (bbmv) from insect midguts are commonly used in the study of the interactions between bacillus thuringiensis cry toxins and their receptors. collaboration between laboratories often require that frozen insect samples are sent in dry ice. because of customs restrictions and delays, sample thawing is always a risk and often the biological material becomes ruined during shipping. we have tested lyophilization as an alternative method for preserving ... | 2004 | 15109901 |
improving the insecticidal activity of bacillus thuringiensis subsp. aizawai against spodoptera exigua by chromosomal expression of a chitinase gene. | a transcriptionally fused gene comprising the p19 gene from bacillus thuringiensis subsp. israelensis fused with a chitinase gene (chibla) from b. licheniformis was integrated into the b. thuringiensis subsp. aizawai bta1 genome by homologous recombination. the resulting b. thuringiensis subsp. aizawai strain (int1) showed growth and sporulation comparable with that of the wild-type strain. int1 produced four chitinases of different molecular masses (i.e., 66, 55, 39, 36 kda). three of these (66 ... | 2004 | 15107949 |
molecular characterization of bacillus thuringiensis strains from argentina. | bacillus thuringiensis inta 7-3, inta 51-3, inta mo9-5 and inta mo14-4 strains were obtained from argentina and characterized by determination of serotype, toxicity, plasmid composition, insecticidal gene content ( cry and vip ) and the cloning of the single- vip3a gene of the inta mo9-5 strain. the serotype analysis identified the serovars tohokuensis and darmstadiensis for the inta 51-3 and inta mo14-4 strains, respectively, whereas the inta mo9-5 strain was classified as "autoagglutinated". i ... | 2004 | 15103240 |
procedures for the evaluation of field efficacy of slow-release formulations of larvicides against aedes aegypti in water-storage containers. | in thailand, water-storage jars, barrels, drums, pails, and tanks constitute vast developmental sites for aedes aegypti in urban, semiurban, and rural areas. earthen water jars, cement jars, and concrete tanks constitute the greatest proportion of artificial containers where ae. aegypti breed. this species is a major vector of the causal agents of dengue and dengue hemorrhagic fever, and vector control by larviciding is one of the main approaches to disease control. at present, temephos sand gra ... | 2004 | 15088706 |
trp132, trp154, and trp157 are essential for folding and activity of a cyt toxin from bacillus thuringiensis. | cyt2aa2 is a cytolytic and mosquito larvicidal toxin produced by bacillus thuringiensis subsp. darmstadiensis. the toxin contains 3 tryptophan residues at positions 132, 154, and 157. to study the role of tryptophan on protein structure and functions, each tryptophan residue was substituted by phenylalanine and other different amino acids. expression test in escherichia coli showed that all mutant proteins were highly produced as inclusion bodies similar to that of the wild type. the mutant w157 ... | 2004 | 15081403 |
[susceptibility of archaea to the antibiotic effect of the parasporal inclusion proteins from bacillus thuringiensis subspecies]. | the proteins of parasporal inclusions from three bacillus thuringiensis subspecies (kurstaki, amagiensis, and monterrey) inhibited growth of methanogenic archaea of two species belonging to two genera, methanobrevibacter arboriphilus and methanosarcina barkeri. the minimal inhibitory concentrations of these proteins were 20 to 50 micrograms/ml. lysozyme exhibited similar bactericidal effect on archaea. the perspective of comparative studies on the effect of polyfunctional proteins on bacteria an ... | 2004 | 15074036 |
biopesticides. | the term 'biopesticide' encompasses a broad array of microbial pesticides, biochemicals derived from micro-organisms and other natural sources, and processes involving the genetic incorporation of dna into agricultural commodities that confer protection against pest damage (plant-incorporated protectants). some microbial pesticides, such as bacillus thuringiensis, have a long history of safe and effective use as a biological insecticide. more recent developments in microbial pest control include ... | 2003 | 15071818 |
designing better probes: effect of probe size, mismatch position and number on hybridization in dna oligonucleotide microarrays. | dna microarrays represent a powerful technology whose use has been hampered by the uncertainty of whether the same principles, established on a scale typical for membrane hybridizations, apply when using the smaller, rigid support of microarrays. our goal was to understand how the number and position of base pair mismatches, probe length and their g+c content affect the intensity and specificity of the hybridization signal. one set of oligonucleotides (50-mers) based on three regions of the baci ... | 2004 | 15063067 |
enhanced expression of insecticidal crystal proteins in wild bacillus thuringiensis strains by a heterogeneous protein p20. | p20 is a small chaperone-like protein encoded by a cry11a operon in bacillus thuringiensis subsp. israelensis (bti); it is essential to cyt1aa expression. in this report, the gene p20 was transformed into wild strains of subsp. kurstaki to raise the yield of crystal proteins. as a result, larger crystals were produced by the transformant than by the wild control, and most were in the form of a big bipyramid (average 2.4 microm long); some were irregular because of too high expression, while the ... | 2004 | 15060726 |
why bt cotton pays for small-scale producers in south africa. | 2004 | 15060543 | |
expression and characterization of a recombinant cry1ac crystal protein with enhanced green fluorescent protein in acrystalliferous bacillus thuringiensis. | to investigate fusion expression between bacillus thuringiensis crystal protein and a foreign protein, the expression of a fusion protein comprised of cry1ac, and enhanced green fluorescent protein (egfp) in b. thuringiensis cry(-)b strain was examined. | 2004 | 15059210 |
endospore degradation in an oligosporogenic, crystalliferous mutant of bacillus thuringiensis. | we isolated a new oligosporogenic mutant from bacillus thuringiensis var. kurstaki hd73 that retains the ability to produce insecticidal crystal inclusions. sporulation in this mutant initiates in a manner similar to the wild-type strain, and under the electron microscope endospores are seen, but these do not reach maturity (except for 0.2% of them). at a late stage, the coat surrounding the forespore seems to lack shape and to be empty. most mutant cells exhibit a well-formed bipyramidal crysta ... | 2004 | 15057485 |
expression of chitinase-encoding genes in bacillus thuringiensis and toxicity of engineered b. thuringiensis subsp. aizawai toward lymantria dispar larvae. | chitinase genes from aeromonas hydrophila and bacillus circulans no.4.1 were cloned into the plasmid phy300plk and designated as phya2 and phyb43, respectively. both plasmids were introduced into various strains of b. thuringiensis by electroporation. plasmid phyb43 was generally structurally stable, but showed lower segregrational stability than phya2 in b. thuringiensis subsp. aizawai when grown under nonselective conditions. the production of chitinase from b. thuringiensis subsp. aizawai har ... | 2004 | 15057461 |
dissection of cry gene profiles of bacillus thuringiensis isolates in taiwan. | on the basis of the newly revised nomenclature system of cry genes, the pcr amplification method has been adopted to resolve the cry gene combinations of 294 bacillus thuringiensis isolates from five selected areas of taiwan. our results indicate that cry1 (especially cry1a + 1b + 1f) and cry2 were the most abundant cry genes in taiwan. in contrast, cry3 and cry6 genes were detected only on yang ming mountain, while the cry13 gene was found only on snow mountain. in addition, some distinctive co ... | 2004 | 15057451 |
in vivo binding of the cry11bb toxin of bacillus thuringiensis subsp. medellin to the midgut of mosquito larvae (diptera: culicidae). | bacillus thuringiensis subsp. medellin produces numerous proteins among which 94 kda known as cry11bb, has mosquitocidal activity. the mode of action of the cry11 proteins has been described as similar to those of the cry1 toxins, nevertheless, the mechanism of action is still not clear. in this study we investigated the in vivo binding of the cry11bb toxin to the midgut of the insect species anopheles albimanus, aedes aegypti, and culex quinquefasciatus by immunohistochemical analysis. spodopte ... | 2004 | 15057351 |
functional analysis of two processed fragments of bacillus thuringiensis cry11a toxin. | the 70-kda protoxin of cry11a, a dipteran-specific insecticidal protein, was processed by trypsin into 36- and 32-kda fragments. to investigate the potent function of the two processed fragments, a gst (glutathione-s-transferase) fusion protein of each polypeptide was constructed. while neither the 36- nor the 32-kda fragment was toxic to culex pipiens larvae, coexpression of the two fragments restored the insecticidal activity. furthermore, the coprecipitation experiment demonstrated that the 3 ... | 2004 | 15056882 |
evaluation of bt (bacillus thuringiensis) corn on mouse testicular development by dual parameter flow cytometry. | the health safety of bt (bacillus thuringiensis) corn (zea mays l.) was studied using mouse testes as a sensitive biomonitor of potential toxic effects. pregnant mice were fed a bt corn or a nontransgenic (conventional) diet during gestation and lactation. after they were weaned, young male mice were maintained on the respective diets. at 8, 16, 26, 32, 63, and 87 days after birth, three male mice and an adult reference mouse were killed, the testes were surgically removed, and the percentage of ... | 2004 | 15053558 |
[detection of genetic modification in maize and maize products by elisa-test]. | enzyme immunoassay methods--trait test--was applied for detection of genetic modification in maize seeds and foodstuffs, which have been produced from this crop. trait test is based on the identification gmo protein cry 1ab produced by a gene derived from bacillus thuringiensis (bt) incorporated into insect resistant corn grain. the experiment was carried out on maize standards and foodstuffs from warsaw market. the positive result was obtained for one maize product, which was not labelled as gm ... | 2003 | 15052732 |
the bacillus thuringiensis cry1aa toxin: effects of trypsin and chymotrypsin site mutations on toxicity and stability. | the objective of the present work was to create an active cry1aa toxin showing enhanced resistance to degradation by spruce budworm (choristoneura fumiferana) midgut proteases by mutating potential chymotrypsin and trypsin sites. fourteen cry1aa mutants were created in an escherichia coli-bacillus shuttle vector and expressed in a crystal minus bacillus thuringiensis host. using spruce budworm gut juice, commercial bovine trypsin and chymotrypsin we performed protease resistance assays with cry1 ... | 2004 | 15050842 |
aerosols from insect control measures show dangers of bioterrorism. | 2003 | 15040200 | |
[effect of transgenic bt rice planting on soil enzyme activities]. | a pot experiment was conducted with silty loam agrodolf as test soil and with transgenic bt rice and non-bt rice as test crops to study the effect of transgenic bt rice planting on soil urease, phophatase, arylsulfatase, invertase, and dehydrogenase activities. the results showed that bt toxin could be introduced into soil through root exudates of transgenic bt rice, and its survival amount in soil varied with time. compared with non-bt rice treatment, transgenic bt rice treatment had a signific ... | 2003 | 15031930 |
identification of bacillus anthracis specific chromosomal sequences by suppressive subtractive hybridization. | bacillus anthracis, bacillus thuringiensis and bacillus cereus are closely related members of the b. cereus-group of bacilli. suppressive subtractive hybridization (ssh) was used to identify specific chromosomal sequences unique to b. anthracis. | 2004 | 15028116 |
bacillus thuringiensis delta-endotoxin binding to brush border membrane vesicles of rice stem borers. | the receptor binding step in the molecular mode of action of five delta-endotoxins (cry1ab, cry1ac, cry1c, cry2a, and cry9c) from bacillus thuringiensis was examined to find toxins with different receptor sites in the midgut of the striped stem borer (ssb) chilo suppressalis (walker) and yellow stem borer (ysb) scirpophaga incertulas (walker) (lepidoptera: pyralidae). homologous competition assays were used to estimate binding affinities (k(com)) of (125)i-labelled toxins to brush border membran ... | 2004 | 15027071 |
a bacillus thuringiensis crystal protein with selective cytocidal action to human cells. | bacillus thuringiensis crystal proteins, well known to be toxic to certain insects but not pathogenic to mammals, are used as insecticidal proteins in agriculture and forest management. we here identified a crystal protein that is non-insecticidal and non-hemolytic but has strong cytocidal activity against various human cells with a markedly divergent target specificity, e.g. highly cytotoxic to hepg2 and jurkat and less cytotoxic to the normal hepatocyte (hc) and hela. in slices of liver and co ... | 2004 | 15026424 |
bacillus thuringiensis toxin (cry1ab) has no direct effect on larvae of the green lacewing chrysoperla carnea (stephens) (neuroptera: chrysopidae). | earlier studies have shown that larvae of the green lacewing predator chrysoperla carnea are negatively affected when preying on lepidopteran larvae that had been fed with transgenic maize expressing the cry1ab gene from bacillus thuringiensis. to test whether the observed effects were directly caused by the cry1ab toxin, we have developed a bioassay which allows us to feed high concentrations of the toxin directly to the predator. the results of these feeding studies show no direct toxic effect ... | 2004 | 15019519 |
isolation and characterization of a strain of bacillus thuringiensis subsp. morrisoni pg-14 encoding delta-endotoxin cry1ac. | bacillus thuringiensis 656-3, isolated from a soil sample collected at mushroom houses, showed high toxicity to mushroom flies, lycoriella mali and coboldia fuscipes. b. thuringiensis 656-3 produced bipyramidal inclusions and reacted with the h antiserum of b. thuringiensis subsp. morrisoni (h8a8b). the plasmid and protein profiles of b. thuringiensis 656-3 were similar to those of its reference strain, subsp. morrisoni pg-14. however, pcr analysis using cry gene primers showed that b. thuringie ... | 2004 | 15018102 |
interaction of two bacillus thuringiensis delta-endotoxins with the digestive system of lygus hesperus. | the active-toxin form of crylac (65 kda) or cry2ab was fed to a non-susceptible insect, lygus hesperus, in an artificial diet. biochemical and immunocytochemical methods were used to determine the distribution of ingested toxin. the toxins did not elicit a feeding deterrent response. crylac and cry2ab were ingested; small amounts were absorbed into the hemolymph as holoproteins, but most was excreted. sds-page analysis of crylac and cry2ab incubations with salivary gland homogenate showed a smal ... | 2004 | 15018095 |
sustainability of transgenic insecticidal cultivars: integrating pest genetics and ecology. | this review examines potential impacts of transgenic cultivars on insect population dynamics and evolution. experience with classically bred, insecticidal cultivars has demonstrated that a solid understanding of both the target insect's ecology and the cultivar's performance under varied field conditions will be essential for predicting area-wide effects of transgenic cultivars on pest and natural enemy dynamics. this experience has also demonstrated the evolutionary capacity of pests for adapti ... | 1998 | 15012402 |
ecology and management of hazelnut pests. | insect and mite pests cause serious damage to the hazelnut crop worldwide. the control strategies used against these pests include application of insecticides, classical and augmentative biological control, utilization of resistant varieties, and use of bacillus thuringiensis-based preparations. in the united states, extensive research has been directed toward elucidating ecological interactions among different pests and natural enemies and understanding the role of abiotic factors in pest popul ... | 1998 | 15012396 |
the naturally derived insecticide spinosad is highly toxic to aedes and anopheles mosquito larvae. | spinosad is a naturally derived biorational insecticide with an environmentally favourable toxicity profile, so we investigated its potency against mosquito larvae (diptera: culicidae). by laboratory bioassays of a suspension concentrate formulation of spinosad (tracer), the 24 h lethal concentration (lc50) against aedes aegypti (l.) third and fourth instars was estimated at 0.025 p.p.m. following logit regression. the concentration-mortality response of third- and fourth-instar anopheles albima ... | 2004 | 15009445 |
interaction of bacillus thuringiensis toxins with larval midgut binding sites of helicoverpa armigera (lepidoptera: noctuidae). | in 1996, bt-cotton (cotton expressing a bacillus thuringiensis toxin gene) expressing the cry1ac protein was commercially introduced to control cotton pests. a threat to this first generation of transgenic cotton is the evolution of resistance by the insects. second-generation bt-cotton has been developed with either new b. thuringiensis genes or with a combination of cry genes. however, one requirement for the "stacked" gene strategy to work is that the stacked toxins bind to different binding ... | 2004 | 15006756 |
reconstruction of bacillus thuringiensis ssp. israelensis cry11a endotoxin from fragments corresponding to its n- and c-moieties restores its original biological activity. | subtilisin hydrolyzes cry11a endotoxin (of 70 kd) produced by bacillus thuringiensis ssp. israelensis to fragments of 33- and 36-kd, which correspond to n- and c-terminal halves of the endotoxin molecule. thermitase (a serine protease from thermoactinomyces vulgaris) and insect gut proteases from diptera and lepidoptera exhibit the same hydrolytic effect on cry11a. hydrolyzates maintain high toxicity with respect to larvae of aedes aegypti, anopheles stephensi, and culex pipiens. the 33- and 36- ... | 2004 | 15000685 |
bacillus thuringiensis var. israelensis production involving re-use of the supernatant. | the supernatant arising after biomass separation of bacillus thuringiensis var. israelensis by flocculation/sedimentation was re-used after being supplemented with 25, 50 and 75% (w/v) of the original culture medium, based on corn steep liquor, glucose and mineral salts. supplementation at 75% gave a spore concentration (1 x 10(10) c.f.u. ml(-1)) five times greater than that obtained with the other supplements. | 2004 | 15000482 |
[advances in safety studies of soil bt toxin proteins released from transgenic bt crops]. | commercialized transgenic bt (bacillus thuringiensis) crops are permitted for field growth in a large scale, which leads to significant issues of ecological risk assessment in soil ecosystem. in this paper, some general safety problems involving in the soil bt active toxins released from insect-resistant transgenic bt crops in the forms of plant residues, root exudates and pollens were reviewed, including their adsorption by soil active-particles, their insecticidal activity, persistence, and bi ... | 2003 | 14997678 |
cross-linking phosphatidylinositol-specific phospholipase c traps two activating phosphatidylcholine molecules on the enzyme. | bacillus thuringiensis phosphatidylinositol-specific phospholipase c (pi-plc), a bacterial model for the catalytic domain of mammalian pi-plc enzymes, was cross-linked by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride to probe for the aggregation and/or conformational changes of pi-plc when bound to activating phosphatidylcholine (pc) interfaces. dimers and higher order multimers (up to 31% of the total protein when cross-linked at ph 7) were observed when the enzyme was cross-linke ... | 2004 | 14996830 |
lower fumonisin mycotoxin levels in the grain of bt corn grown in the united states in 2000-2002. | fumonisins were monitored in corn grain collected from bt hybrids grown in 107 locations across the united states in 2000-2002. bt corn hybrids contain the cry1ab protein from bacillus thuringiensis that controls european corn borers and other stalk-boring pests. fumonisin levels were frequently lower in grain from bt hybrids grown in field trials under conditions of natural (fact trials) or manual insect infestation (university trials). over three years of fact trials, there were 126/210 compar ... | 2004 | 14995151 |
detection and quantitation of genetically modified maize (bt-176 transgenic maize) by applying ligation detection reaction and universal array technology. | we have applied the ligation detection reaction (ldr) combined with a universal array approach to the detection and quantitation of the polymerase chain reaction (pcr) amplified cry1a(b) gene from bt-176 transgenic maize. we demonstrated excellent specificity and high sensitivity. down to 0.5 fmol (nearly 60 pg) of pcr amplified transgenic material was unequivocally detected with excellent linearity within the 0.1-2.0% range with respect to wild-type maize. we suggest the feasibility of extendin ... | 2004 | 14995096 |
laboratory and field evaluation of tebufenozide, diflubenzuron, and bacillus thurengiensis var. kurstaki for suppression of douglas-fir tussock moth (orgyia pseudotsugata (mcdunnough)) in idaho: a case study. | the insect growth regulator tebufenozide (mimic 2lv) was tested to examine its impact on the douglas-fir tussock moth, orgyia pseudotsugata (mcdunnough) (lepidoptera: lymantriidae). laboratory tests gave an estimated concentration of 1.26 ppm of the compound to achieve 50% population mortality (lc50) for second-instar o. pseudotsugata. at the highest concentration tested, tebufenozide resulted in significant larval mortality within 7 d with an estimated time to 50% population mortality (lt50) of ... | 2003 | 14994806 |
design and evaluation of an aerial spray trial with true replicates to test the efficacy of bacillus thuringiensis insecticide in a boreal forest. | a field trial using true replicates was conducted successfully in a boreal forest in 1996 to evaluate the efficacy of two aerially applied bacillus thuringiensis formulations, abg 6429 and abg 6430. a complete randomized design with four replicates per treatment was chosen. twelve to 15 balsam fir (abies balsamea [l.] mill.) per plot were randomly selected as sample trees. interplot buffer zones, > or = 200 m wide, adequately prevented cross contamination from sprays that were atomized with four ... | 2003 | 14994805 |
preparation of spray-dried wettable powder formulations of bacillus thuringiensis-based biopesticides. | bacillus thuringiensis is the most widely used biopesticide among many methods available to control insects. to make a saleable product, b. thuringiensis must be substantially concentrated by removal of water and formulated to improve longevity, efficacy, and ease of transport of the product. b. thuringiensis subsp. aizawai culture broth as an active ingredient was mixed with various adjuvants and then spray dried. the optimum conditions for spray drying were found to be an outlet temperature of ... | 2003 | 14994793 |
lethal and sublethal effects of single and double applications of bacillus thuringiensis variety kurstaki on spruce budworm (lepidoptera: tortricidae) larvae. | we conducted laboratory experiments to examine the effects of single versus double exposures of spruce budworm, choristoneura fumiferana (lepidoptera: tortricidae) female larvae to various concentrations of a bacillus thuringiensis variety kurstaki (btk) commercial formulation (foray 48b). our main objective was to document the vulnerability to btk and the sublethal responses of fifth-instar larvae that survived from a first ingestion of btk during their fourth stadium and to compare them with i ... | 2003 | 14994791 |
novel cry gene from paenibacillus lentimorbus strain semadara inhibits ingestion and promotes insecticidal activity in anomala cuprea larvae. | a positive clone was selected from a library of total cell dna of paenibacillus lentimorbus strain semadara that reacted with an antiserum that was raised against parasporal crystal proteins produced by this strain. the positive clone had a dna insert containing two whole cry genes (cry43aa1, cry43ba1), one partial cry gene (cry43-like), and three smaller genes located upstream. eight blocks that are conserved in the cry proteins of bacillus thuringiensis [microbiol. mol. biol. rev. 62 (1998) 77 ... | 2004 | 14992857 |
a novel synthetic peptide derivative from lactoferrin exhibiting antimicrobial activity. | a tetrapeptide derivative boc-l-lys(boc)-l-arg-l-asp-l-ser(bu(t))-obu(t) (pep 1261; boc is butoxycarbonyl, bu(t) is t-butyl and obu(t) is t-butyl ester), synthesized by a solution-phase strategy, exhibited antimicrobial activity against a broad spectrum of micro-organisms at an optimal concentration of 500 mug/ml. whereas the tetrapeptide salt (l-lys-l-arg-l-asp-l-ser.hcl) was found to be fairly effective against bacterial cultures, it was not effective against fungal cultures. comparative growt ... | 2004 | 14992693 |
induction and transmission of bacillus thuringiensis tolerance in the flour moth ephestia kuehniella. | the use of bacillus thuringiensis (bt) endotoxins to control insect vectors of human diseases and agricultural pests is threatened by the possible evolution of resistance in major pest species. in addition to high levels of resistance produced by receptor insensitivity (5, 16, 17), several cases of tolerance to low to medium levels of toxin have been reported in laboratory colonies of lepidopteran species (3, 18). because the molecular basis of some of these cases of tolerance to the toxin are n ... | 2004 | 14978282 |