Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| effect of maysin on wild-type, deltamethrin-resistant, and bt-resistant helicoverpa armigera (lepidoptera: noctuidae). | larvae of the old world corn earworm, helicoverpa armigera (hübner), were fed diets containing lyophilized silks from maize genotypes expressing varying levels of maysin, a flavone glycoside known to be toxic to the new world corn earworm, helicoverpa zea boddie. three different h. armigera colonies were tested: a wild-type colony (96-s), a colony selected for resistance to deltamethrin (del-r), and a colony selected for resistance to the cry1ac protoxin of bacillus thuringiensis (bt-r). a colon ... | 2003 | 12852635 |
| development, survival and fitness performance of helicoverpa zea (lepidoptera: noctuidae) in mon810 bt field corn. | helicoverpa zea (boddie) development, survival, and feeding injury in mon810 transgenic ears of field corn (zea mays l.) expressing bacillus thuringiensis variety kurstaki (bt) cry1ab endotoxins were compared with non-bt ears at four geographic locations over two growing seasons. expression of cry1ab endotoxin resulted in overall reductions in the percentage of damaged ears by 33% and in the amount of kernels consumed by 60%. bt-induced effects varied significantly among locations, partly becaus ... | 2003 | 12852636 |
| effects of mon810 bt field corn on adult emergence of helicoverpa zea (lepidoptera: noctuidae). | a 3-yr study (1996-1998) was conducted to evaluate the effects of mon810 bt corn on helicoverpa zea (boddie) emergence and to determine whether delayed larval development as a result of bt intoxication results in higher levels of diapause induction and pupal mortality. in the 1997 study, there was no difference in prepupal mortality between corn types, although significantly more prepupae from bt plots than from non-bt plots died in emergence buckets before constructing pupal chambers in 1998. i ... | 2003 | 12852637 |
| effect of mon810 bt field corn on helicoverpa zea (lepidoptera: noctuidae) cannibalism and its implications to resistance development. | pairs of helicoverpa zea (boddie) larvae reared on diet-incorporated mon810 transgenic leaf tissue of field corn (zea mays l.) were observed in the laboratory to characterize effects of sublethal levels of bacillus thuringiensis variety kurstaki (bt) cry1ab endotoxins on cannibalistic behavior and mortality. feeding on sublethal levels of bt corn reduced the frequency of cannibalistic behaviors exhibited by h. zea when uneven instars were paired together. exposure to the bt endotoxin had no sign ... | 2003 | 12852638 |
| evaluation of transgenic bt corn for resistance to the asian corn borer (lepidoptera: pyralidae). | the asian corn borer, ostrinia furnacalis (guenée), is the most important insect pest on corn in china. bt transgenic corn provides a new tool for asian corn borer control. monsanto's yieldgard bt transgenic corn expressing cry1ab protein, and a non-bt control, were evaluated in beijing. laboratory bioassays were carried out by exposing neonates to an agar-free diet containing bt corn whorl leaves, tassels, and anthers, or by exposing neonates directly to fresh silk and pollen. these are the tis ... | 2003 | 12852639 |
| economic analysis of planting dates to manage european corn borer (lepidoptera: crambidae) with bt corn. | planting dates of transgenic bacillus thuringiensis berliner (bt) corn were adjusted to determine the utility in managing european corn borer, ostrinia nubilalis (hübner). transgenic bt (events 176 and bt11) corn and non-bt corn were planted at three different times to use the early- and late- planted corn as a potential trap crop for ovipositing european corn borer moths. grain moisture and yields were recorded to determine the economic benefits of bt corn planted on the different dates, based ... | 2003 | 12852640 |
| transgenic bacillus thuringiensis corn hybrid performance against univoltine ecotype european corn borer (lepidoptera: crambidae) in south dakota. | the performances of bt-corn hybrids against univoltine ecotype european corn borer larvae were evaluated in south dakota from 1997 to 1999. the corn hybrids were exposed to natural seasonal fluctuations of a univoltine ecotype european corn borer population. larval injury parameters, grain yields, and gross incomes were quantified during the 3-yr study. in general, the bt-corn hybrids had significantly higher yields than the untreated non-bt isolines in 1997 and 1998 when corn borer pressures we ... | 2003 | 12852642 |
| pest resistance feared as farmers flout rules. | 2003 | 12853913 | |
| comparison of the expression of bacillus thuringiensis full-length and n-terminally truncated vip3a gene in escherichia coli. | studies were performed to demonstrate the function of the putative signal peptide of vip3a proteins in escherichia coli. | 2003 | 12859763 |
| molecular typing of bacillus thuringiensis serovars by rapd-pcr. | one hundred and twenty-six strains of bacillus thuringiensis representing 57 serovars were allocated to 58 genomic types using random amplified polymorphic dna (rapd)-pcr patterns. serovars darmstadiensis, israelensis, kenyae, kumamotoensis, kurstaki, morrisoni, pakistani, sotto, thuringiensis and tolworthi each encompassed identical or closely related strains. despite this genomic homogeneity, most of these serovars also included at least one variant strain. serovars aizawai, canadensis, entomo ... | 2003 | 12866852 |
| the hidden lifestyles of bacillus cereus and relatives. | bacillus cereus sensu lato, the species group comprising bacillus anthracis, bacillus thuringiensis and b. cereus (sensu stricto), has previously been scrutinized regarding interspecies genetic correlation and pathogenic characteristics. so far, little attention has been paid to analysing the biological and ecological properties of the three species in their natural environments. in this review, we describe the b. cereus sensu lato living in a world on its own; all b. cereus sensu lato can grow ... | 2003 | 12871230 |
| a constitutively expressed 36 kda exochitinase from bacillus thuringiensis hd-1. | a 36 kda chitinase was purified by ion exchange and gel filtration chromatography from the culture supernatant of bacillus thuringiensis hd-1. the chitinase production was independent of the presence of chitin in the growth medium and was produced even in the presence of glucose. the purified chitinase was active at acidic ph, had an optimal activity at ph 6.5, and showed maximum activity at 65 degrees c. of the various substrates, the enzyme catalyzed the hydrolysis of the disaccharide 4-mu(gln ... | 2003 | 12893268 |
| the mode of action of the bacillus thuringiensis vegetative insecticidal protein vip3a differs from that of cry1ab delta-endotoxin. | the vip3a protein, secreted by bacillus spp. during the vegetative stage of growth, represents a new family of insecticidal proteins. in our investigation of the mode of action of vip3a, the 88-kda vip3a full-length toxin (vip3a-f) was proteolytically activated to an approximately 62-kda core toxin either by trypsin (vip3a-t) or lepidopteran gut juice extracts (vip3a-g). biotinylated vip3a-g demonstrated competitive binding to lepidopteran midgut brush border membrane vesicles (bbmv). furthermor ... | 2003 | 12902253 |
| pgil01, a linear tectiviral plasmid prophage originating from bacillus thuringiensis serovar israelensis. | bacillus thuringiensis serovar israelensis harbours, in addition to several circular plasmids, a small linear molecule of about 15 kb. sequence analysis of this molecule, named pgil01, showed the presence of at least 30 orfs, five of which displayed similarity with proteins involved in phage systems: a b-type family dna polymerase, a lexa-like repressor, two potential muramidases and a dna-packaging protein (distantly related to the p9 protein of the tectiviral phage prd1). experimental evidence ... | 2003 | 12904548 |
| binding of bacillus thuringiensis toxins in resistant and susceptible strains of pink bollworm (pectinophora gossypiella). | evolution of resistance by pests could cut short the success of transgenic plants producing toxins from bacillus thuringiensis, such as bt cotton. the most common mechanism of insect resistance to b. thuringiensis is reduced binding of toxins to target sites in the brush border membrane of the larval midgut. we compared toxin binding in resistant and susceptible strains of pectinophora gossypiella, a major pest of cotton worldwide. using cry1ab and cry1ac labeled with (125)i and brush border mem ... | 2003 | 12915184 |
| beta-glucosidase enzymatic activity of crystal polypeptide of the bacillus thuringiensis strain 1.1. | the crystals of bacillus thuringiensis strain 1.1 consist of the 140 kda delta-endotoxin, which exhibits beta-glucosidase enzymatic activity, based on the following data. (i) purified crystals exhibit beta-glucosidase enzymatic activity. when the crystals are reacted with specific antibodies directed either against the commercial (almond purified) beta-glucosidase or against the 140 kda polypeptide, then considerable reduction of enzymatic activity is observed almost at the same level with both ... | 2003 | 12935352 |
| cross-resistance between strains of bacillus sphaericus but not b. thuringiensis israelensis in colonies of the mosquito culex quinquefasciatus. | two colonies of culex quinquefasciatus say (diptera: culicidae) were selected with bacillus sphaericus strains c3-41 and iab59 in the laboratory for 13 and 18 generations; they attained 145,000- and 48.3-fold resistance, respectively, in comparison with a susceptible laboratory colony (slcq) and showed very high levels of cross-resistance (8500- to 145,000-fold) to b. sphaericus strains c3-41, 1593, 2297 and 2362. they were relatively susceptible to b. sphaericus strains lp1-g and 47-6b (only 0. ... | 2003 | 12941008 |
| resistance to a bacterial toxin is mediated by removal of a conserved glycosylation pathway required for toxin-host interactions. | crystal (cry) proteins made by the bacterium bacillus thuringiensis are pore-forming toxins that specifically target insects and nematodes and are used around the world to kill insect pests. to better understand how pore-forming toxins interact with their host, we have screened for caenorhabditis elegans mutants that resist cry protein intoxication. we find that cry toxin resistance involves the loss of two glycosyltransferase genes, bre-2 and bre-4. these glycosyltransferases function in the in ... | 2003 | 12944392 |
| [effect of mineral nutrition sources on the growth and toxin formation of the entomopathogenic bacteria bacillus thuringiensis]. | mineral composition of culture medium has been studied for its effect on the processes of growth, spore-and-toxin formation of entomopathogenic bacteria bacillus thuringiensis. it has been shown that salts na2so4, na2sio3.9h2o, mgso4.7h2o increase the yield of biomass and endotoxin; feso4.7h2o, cacl2, mnso4.4h2o increase only the yield of biomass; cdso4.7h2o and cocl2.6h2o--inhibit the processes of spore-and-toxin formation, but increase the cell titre. a complex of mineral salts has been found ... | 2003 | 12945189 |
| resistance to bt toxin surprisingly absent from pests. | 2003 | 12949541 | |
| bt crop risk assessment in the netherlands. | 2003 | 12949550 | |
| are bt crops safe? | 2003 | 12949561 | |
| molecular basis for bacillus thuringiensis cry1ab toxin specificity: two structural determinants in the manduca sexta bt-r1 receptor interact with loops alpha-8 and 2 in domain ii of cy1ab toxin. | the identification of epitopes involved in cry toxin-receptor interaction could provide insights into the molecular basis of insect specificity and for designing new toxins to overcome the potential problem of insect resistance. in previous works, we determined that the manduca sexta cry1a cadherin-like receptor (bt-r(1)) interacts with cry1a toxins through epitope (865)nitihitdtnn(875) and by loop 2 of domain ii in the toxin (gomez, i., miranda-rios, j., rudiño-piñera, e., oltean, d. i., gill, ... | 2003 | 12950175 |
| comparative analysis of bacterial viruses bam35, infecting a gram-positive host, and prd1, infecting gram-negative hosts, demonstrates a viral lineage. | extra- and intracellular viruses in the biosphere outnumber their cellular hosts by at least one order of magnitude. how is this enormous domain of viruses organized? sampling of the virosphere has been scarce and focused on viruses infecting humans, cultivated plants, and animals as well as those infecting well-studied bacteria. it has been relatively easy to cluster closely related viruses based on their genome sequences. however, it has been impossible to establish long-range evolutionary rel ... | 2003 | 12954208 |
| identification of cry1i-type genes from bacillus thuringiensis strains and characterization of a novel cry1i-type gene. | a pcr-restriction fragment length polymorphism method for identification of cry1i-type genes from bacillus thuringiensis was established by designing a pair of universal primers based on the conserved regions of the genes to amplify 1,548-bp cry1i-type gene fragments. amplification products were digested with the bsp119i and bani enzymes, and four kinds of known cry1i-type genes were successfully identified. the results showed that cry1i-type genes appeared in 95 of 115 b. thuringiensis isolates ... | 2003 | 12957903 |
| diversity of bacillus thuringiensis strains from latin america with insecticidal activity against different mosquito species. | the characterization of selected bacillus thuringiensis strains isolated from different latin america countries is presented. characterization was based on their insecticidal activity against aedes aegypti, culex quinquefasciatus, and anopheles albimanus larvae, scanning electron microscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and plasmid profiles as well as pcr analysis using novel general and specific primers for cry and cyt genes encoding proteins active against mosquit ... | 2003 | 12957913 |
| introduction of culex toxicity into bacillus thuringiensis cry4ba by protein engineering. | bacillus thuringiensis mosquitocidal toxin cry4ba has no significant natural activity against culex quinquefasciatus or culex pipiens (50% lethal concentrations [lc(50)], >80,000 and >20,000 ng/ml, respectively). we introduced amino acid substitutions in three putative loops of domain ii of cry4ba. the mutant proteins were tested on four different species of mosquitoes, aedes aegypti, anopheles quadrimaculatus, c. quinquefasciatus, and c. pipiens. putative loop 1 and 2 exchanges eliminated activ ... | 2003 | 12957922 |
| effects of bacillus thuringiensis toxin on hepatic lipid peroxidation and free-radical scavengers in rats given alpha-tocopherol or acetylsalicylate. | the effect of dipel (d), a bacillus thuringiensis-based bioinsecticide, on hepatic antioxidant enzyme activities and lipid peroxidation in rat liver was investigated. administration of d in a dose of 1 mg/100 g body mass for 4 successive days increased the activities of glutathione peroxidase (gpx), glutathione reductase (gr) and the level of malondialdehyde (mda) in rat hepatocytes. the activity of superoxide dismutase (sod) and glutathione (gsh) level were decreased. administration of d in rat ... | 2003 | 12965185 |
| evaluation of the impact of bacillus thuringiensis serovar israelensis and temephos, used for the control of simulium (chirostilbia) pertinax kollar, 1832 (diptera, simuliidae) on the associated entomofauna, paraty, state of rio de janeiro, brazil. | the study was set up to evaluate the impact of two commercial larvicide formulations, bacillus thuringiensis serovar israelensis base (bti) at 15 ppm/1 min and temephos at 0.03 ppm of active ingredient, used to control simulium pertinax populations, on associated non-target entomofauna occupying the same breeding sites. the experiments were carried out on the pedra branca and muricana rivers, on the slopes of serra do mar massif, municipality of paraty, state of rio de janeiro, brazil. bti was a ... | 2003 | 12973540 |
| bacillus thuringiensis serovar israelensis is highly toxic to the coffee berry borer, hypothenemus hampei ferr. (coleoptera: scolytidae). | a native collection of bacillus thuringiensis strains was screened, once a reliable bioassay technique to assess the toxicity against the coffee berry borer (cbb) first-instar larvae was developed. a first round of bioassays with 170 strains indicated that the great majority of them showed no or very little insecticidal activity and that very few showed significant levels of toxicity. interestingly, only those strains that had previously been associated with mosquitocidal activity were also toxi ... | 2003 | 13129610 |
| estimated frequency of nonrecessive bt resistance genes in bollworm, helicoverpa zea (boddie) (lepidoptera: noctuidae) in eastern north carolina. | in summer 2000, adult female bollworm moths, helicoverpa zea (boddie), were collected from light-traps at four locations near the tidewater research station, plymouth, nc. female moths were allowed to lay eggs, and at hatch, 72 larvae from each female were screened for growth rate on normal artificial diet and on diets containing 5.0 microg of either cry1ac or cry2aa bt toxin per milliliter of diet. the growth rate bioassays were performed to isolate nonrecessive bt resistance genes present in f ... | 2003 | 12650356 |
| spatial processes in the evolution of resistance in helicoverpa zea (lepidoptera: noctuidae) to bt transgenic corn and cotton in a mixed agroecosystem: a biology-rich stochastic simulation model. | a simulation model is developed to examine the role of spatial processes in the evolution of resistance in helicoverpa zea populations to bt corn and bt cotton. the model is developed from the stochastic spatially explicit heliothis virescens model described by peck et al. (1999), to accommodate a spatial mix of two host crops (corn and cotton), and to reflect the agronomic practices, as well as the spatial and temporal population dynamics of h. zea, in eastern north carolina. the model suggests ... | 2003 | 12650359 |
| sensitivity analysis of a spatially-explicit stochastic simulation model of the evolution of resistance in helicoverpa zea (lepidoptera: noctuidae) to bt transgenic corn and cotton. | the sensitivities of a model simulating the evolution of resistance in helicoverpa zea to bt toxins in transgenic crops were investigated by examining effects of each of the model parameters on the frequency of resistance alleles after 8 yr. the functional dominance of resistance alleles and the initial frequency of those alleles had a major impact on resistance evolution. the survival of susceptible insects on the transgenic crops and the population dynamics of the insect, driven by winter surv ... | 2003 | 12650360 |
| effects of bacillus thuringiensis cry1ab toxin on mammalian cells. | the cry proteins produced by bacillus thuringiensis are considered to be highly specific insecticidal proteins. judged to be safe for humans and farm animals due to their insect-oriented selective toxicity, the proteins have been utilized as a biological pesticide and introduced into genetically modified plants. however, some critical fundamental characters of the cry proteins remain unclear, and the direct effects of activated cry proteins on mammalian cells have not yet been fully confirmed. t ... | 2003 | 12655112 |
| symptom complaints following aerial spraying with biological insecticide foray 48b. | to investigate the effect of aerial bacillus thuringiensis (foray 48b) spraying on self-reported symptom complaints, health perceptions, and visits to healthcare providers. | 2003 | 12658313 |
| advances in plant biotechnology and its adoption in developing countries. | developing countries are already benefiting and should continue to benefit significantly from advances in plant biotechnology. insect-protected cotton containing a natural insecticide protein from bacillus thuringiensis (bt cotton) is providing millions of farmers with increased yields, reduced insecticide costs and fewer health risks. many other useful plant biotechnology products that can benefit poor farmers and consumers are in the research and development pipelines of institutions in develo ... | 2003 | 12667878 |
| antibacterial activity of cry- and cyt-proteins from bacillus thuringiensis ssp. israelensis. | mosquitocidal endotoxins cry4b, cry11a, and cyta from bacillus thuringiensis ssp. israelensis as well as the products of their limited proteolysis display antibacterial activity relative to micrococcus luteus. the endotoxin cry11a also induces the lysis of the micrococcus protoplasts. potassium and sodium ions and n-acetylgalactosamine increased the antibacterial effect of cry11a, whereas glucose and n-acetylglucosamine inhibited it. the endotoxin cry11a displays the antibacterial effect on some ... | 2003 | 12674346 |
| emergence of resistance and resistance management in field populations of tropical culex quinquefasciatus to the microbial control agent bacillus sphaericus. | in recent years, highly potent mosquitocidal strains of the microbial agent bacillus sphaericus (bsph) have been isolated and developed for the control of mosquito larvae around the world. laboratory selection experiments with the most active strains and their use in large-scale operational mosquito control programs resulted in the emergence of resistance in larvae of the culex pipiens complex. this generated great concern among vector control agencies around the world, who feared reduced effica ... | 2003 | 12674533 |
| ice granules containing endotoxins of microbial agents for the control of mosquito larvae--a new application technique. | this study investigated a new method for delivering microbial mosquito control agents into aquatic sites as ice granules for mosquito control. solutions containing powder formulations of bacillus thuringiensis israelensis (bti) or bacillus sphaericus were transformed into ice pellets (named icypearls) using a special ice-making machine. this new technique was demonstrated to have the following advantages over bti sand granules: 1) the bti ice pellets melted on the water surface and released the ... | 2003 | 12674537 |
| enhancement of the efficacy of a combination of mesocyclops aspericornis and bacillus thuringiensis var. israelensis by community-based products in controlling aedes aegypti larvae in thailand. | prolonged efficacy of a combination of bacteria (bacillus thuringiensis var. israelensis [bti] and copepods (mesocyclops aspericornis) in controlling immature forms of aedes aegypti in peridomestic water containers was achieved by adding various products from local villages as supplementary food for copepods. in all experiments, 100 first-instar larvae were added into the breeding containers every day for eight weeks. combinations of biological control agents and each local supplementary food we ... | 2003 | 13677377 |
| an improved baculovirus insecticide producing occlusion bodies that contain bacillus thuringiensis insect toxin. | baculovirus occlusion bodies, large proteinaceous structures which contain virions, have recently been engineered to incorporate foreign proteins. the major constituent protein of occlusion bodies from the baculovirus autographa californica nucleopolyhedrovirus is polyhedrin, and assembly of recombinant occlusion bodies which incorporate a foreign protein depends on an interaction between native polyhedrin and a polyhedrin-foreign protein fusion. this technology has now been applied to the gener ... | 2003 | 13678710 |
| additive transgene expression and genetic introgression in multiple green-fluorescent protein transgenic crop x weed hybrid generations. | the level of transgene expression in crop x weed hybrids and the degree to which crop-specific genes are integrated into hybrid populations are important factors in assessing the potential ecological and agricultural risks of gene flow associated with genetic engineering. the average transgene zygosity and genetic structure of transgenic hybrid populations change with the progression of generations, and the green fluorescent protein (gfp) transgene is an ideal marker to quantify transgene expres ... | 2003 | 13679991 |
| insect resistance to transgenic bt crops: lessons from the laboratory and field. | transgenic crops that produce insecticidal toxins from the bacterium bacillus thuringiensis (bt) grew on >62 million ha worldwide from 1996 to 2002. despite expectations that pests would rapidly evolve resistance to such bt crops, increases in the frequency of resistance caused by exposure to bt crops in the field have not yet been documented. in laboratory and greenhouse tests, however, at least seven resistant laboratory strains of three pests (plutella xylostella [l.], pectinophora gossypiell ... | 2003 | 14503572 |
| novel fermentation media for production of bacillus thuringiensis subsp. israelensis. | the production of bacillus thuringiensis subsp. israelensis (debarjac) (bti) as a biopesticide is not cost-effective using existing fermentation technology. in this study, we explored the use of several less expensive alternative culture media (potato, common sugar, and bengal gram) for the growth and production of bti. growth was obtained in all tested media and was comparable to that obtained in conventional medium (luria-bertani). toxicity assays showed that the toxin produced from the novel ... | 2003 | 14503573 |
| resistance to the cry1ac delta-endotoxin of bacillus thuringiensis in the cotton bollworm, helicoverpa armigera (lepidoptera: noctuidae). | three laboratory strains of helicoverpa armigera (hübner) were established by mating of field-collected insects with an existing insecticide-susceptible laboratory strain. these strains were cultured on artificial diet containing the cry1ac protoxin of bacillus thuringiensis using three different protocols. when no response to selection was detected after 7-11 generations of selection, the three strains were combined by controlled mating to preserve genetic diversity. the composite strain (bx) w ... | 2003 | 14503603 |
| efficacy of transgenic cotton containing a cry1ac gene from bacillus thuringiensis against helicoverpa armigera (lepidoptera: noctuidae) in northern china. | nucotn 33b, a bt transgenic variety of upland cotton (gossypium hirsutum l.) expressing the insecticidal protein cry1ac from bacillus thuringiensis berliner sp. kurstaki, was evaluated for resistance to helicoverpa armigera (hübner) during 1998-2000 in northern china. the results indicated that there was no significant difference in egg densities between nucotn 33b and three nontransgenic varieties (dp5415, zhongmian12, and shiyuan321) during the season, although the survival of larvae on nucotn ... | 2003 | 14503607 |
| neural networks applied to the prediction of fed-batch fermentation kinetics of bacillus thuringiensis. | this paper proposes using a new recurrent neural network model (rnnm) to predict and control fed batch fermentations of bacillus thuringiensis. the control variables are the limiting substrate and the feeding conditions. the multi-input multi-output rnnm proposed has twelve inputs, seven outputs, nineteen neurons in the hidden layer, and global and local feedbacks. the weight update learning algorithm designed is a version of the well known backpropagation through time algorithm directed to the ... | 2003 | 14505001 |
| identification of novel bacillus thuringiensis cry1ac binding proteins in manduca sexta midgut through proteomic analysis. | the crystal proteins of bacillus thuringiensis are widely used in transgenic crops and commercially available insecticides. manduca sexta, the tobacco hornworm, is the model insect for b. thuringiensis studies. although brush border vesicles prepared from larval m. sexta midgut have been used in numerous mode-of-action studies of b. thuringiensis toxins, their protein components are mostly unknown. vesicles prepared from the brush border of m. sexta midgut were analyzed using one- and two-dimens ... | 2003 | 14505693 |
| recombinant bacteria for mosquito control. | bacterial insecticides have been used for the control of nuisance and vector mosquitoes for more than two decades. nevertheless, due primarily to their high cost and often only moderate efficacy, these insecticides remain of limited use in tropical countries where mosquito-borne diseases are prevalent. recently, however, recombinant dna techniques have been used to improve bacterial insecticide efficacy by markedly increasing the synthesis of mosquitocidal proteins and by enabling new endotoxin ... | 2003 | 14506223 |
| identification of a novel dna methyltransferase activity from bacillus thuringiensis. | a dna methyltransferase activity was identified in a strain of bacillus thuringiensis that was found to protect dna from cleavage by the restriction endonuclease haeiii at overlapping sites. site-directed mutagenesis was used to confirm therecognition sequence of the methyltransferase as acggc. | 2003 | 14506863 |
| pathogenicity of bacillus thuringiensis isolated from two species of acromyrmex (hymenoptera, formicidae). | the control of acromyrmex leaf-cutting ants is necessary due to the severe damage they cause to diverse crops. a possibility was to control them using the bacterium bacillus thuringiensis (bt) that characteristically produces insecticidal crystal proteins (icps). the icps have been effective in controlling lepidopterans, dipterans, and coleopterans, but their action against hymenopterans is unknown. this paper describes an attempt to isolate bt from ants of two acromyrmex species, to evaluate it ... | 2003 | 14509852 |
| enduring toxicity of transgenic anabaena pcc 7120 expressing mosquito larvicidal genes from bacillus thuringiensis ssp. israelensis. | persistence of biological control agents against mosquito larvae was tested under simulated field conditions. mosquito larvicidal activity of transgenic anabaena pcc 7120 expressing cry4aa, cry11aa and p20 from bacillus thuringiensis ssp. israelensis was greater than b. thuringiensis ssp. israelensis primary powder (fun 89c06d) or wettable powder (wp) (bactimos products) when either mixed with silt or exposed to sunlight outdoors. reduction of bactimos primary powder toxicity was at least 10-fol ... | 2003 | 14510853 |
| relocating expression of vegetative insecticidal protein into mother cell of bacillus thuringiensis. | vegetative insecticidal protein (vip) is a class of insecticidal proteins produced by some strains of bacillus thuringiensis during the vegetative stage of their growth. unlike delta-endotoxins which are produced as parasporal inclusion bodies within the cell during sporulation, vip is secreted into the culture medium. here we report the relocation of the expression of vip into the mother cell compartment in a manner similar to well-characterized cry proteins. relocation of vip is directed to mo ... | 2003 | 14511664 |
| epitope tagging: a monoclonal antibody specific for recombinant fusion proteins in plants. | the easy identification of a recombinant protein in plant material becomes increasingly relevant as more transgenic plants are used for research and commercial applications. tagging recombinant proteins with a small peptide (epitope) can perform such a task. however, available epitope antibodies will also cross-react with endogenous plant proteins at a level that may be unacceptable. here we describe the new epitope antibody acv5. whether it is attached to the carbooxyl terminal end of enhanced ... | 2003 | 14513553 |
| [the difficulty of obtaining immunologic responses in mucosae. use of coadjuvants]. | the search of immunogenicity represents a real problem to be solved with the new techniques to vaccines design. despite of numerous initiatives to increase the immune response at mucosal sites, there are few substances available to exert an adequate immunogenicity in mucosal compartments. on this hand the research on mucosal adjuvants has arise interest. mechanism of both: immunogenicity and adjuvanticity, were reviewed putting emphasis mainly in two mucosal adjuvants, cholera toxin and the prot ... | 2003 | 14513603 |
| characterization of a novel cry2aa-type gene from bacillus thuringiensis subsp. kurstaki. | a 4 kb bamhi-hindili fragment, corresponding to the cry2a operon of bacillus thuringiensis subsp. kurstaki strain bns3, was cloned. the sequencing of the corresponding cry2aa-type gene, termed crybns3-4, revealed an open reading frame of 1902 bp, encoding a protein of 633 amino-acid residues. both nucleotide and amino-acid sequences similarity analysis revealed that crybns3-4 is a new cry2aa-type gene which has several differences from the reported cry2aa-type genes. the transfer of the cloned o ... | 2003 | 14514070 |
| [inter- and intraspecies conjugal transfer of different plasmids in bacilli]. | conjugal transfer of plasmid pub110 between different strains of bacilli was studied. the plasmid transfer was possible not only between various strains of b. subtilis, but also when many other species of bacilli served as recipients. conjugation of a donor strain b. subtilis 19 (p19pub110) was accompanied by a transfer of plasmid p19 along with plasmid pub110 to the b. subtilis recipient strains lacking a large plasmid p19. if, like the donor cells, the recipient b. subtilis strain carried plas ... | 2003 | 14515473 |
| efficacy of bacillus thuringiensis israelensis, bacillus sphaericus and temephos for managing anopheles larvae in eritrea. | we evaluated the larvicidal activity of the granular formulation of bacillus thuringiensis israelensis (bti) serotype h-14 (vectobac g, 200 itu/mg) and bacillus sphaericus (bsph) serotype h5a5b (vectolex cg, 670 bs itu/mg) against anopheles arabiensis and other mosquitoes in breeding habitats in 3 sites, gash-barka, anseba, and debub zones, in eritrea. the primary objective was to determine the optimal application rate and duration of effect for bti and bsph in representative larval habitats as ... | 2003 | 14524547 |
| specific oxygen uptake rate variations during batch fermentation of bacillus thuringiensis subspecies kurstaki hd-1. | the specific oxygen uptake rate (q(o)2, respiration rate) of bacillus thuringiensis subsp. kurstaki hd-1 was very high at inoculation and was found to decrease essentially monotonically throughout both vegetative growth phase and transition phase under different batch culture conditions. average q(o)2 values decreased from 8-10 mmol/g h at 1 h after inoculation to less than 2 mmol/g h by the time growth ended. the results are shown to be consistent with the few previous reports on q(o)2 in b. th ... | 2003 | 14524704 |
| mutation of the hydrophobic residue on helix alpha5 of the bacillus thuringiensis cry4b affects structural stability. | cry4b toxin is a mosquito-larvicidal protein from the bacillus thuringiensis subsp. israelensis. we have investigated the role of two conserved hydrophobic residues of cry4b in structural stabilization. substitutions of the leucine-175 and isoleucine-189 on helix alpha5 with valine and leucine did not affect the expression level, solubility and proteolytic processing. steady state analysis of an unfolding experiment as monitored by circular dichroism and fluorescence spectroscopy demonstrated a ... | 2003 | 14529489 |
| a novel real-time quantitative pcr method using attached universal template probe. | a novel real-time quantitative polymerase chain reaction (pcr) method using an attached universal template (ut) probe is described. the ut is an approximately 20 base attachment to the 5' end of a pcr primer, and it can hybridize with a complementary taqman probe. one of the advantages of this method is that different target dna sequences can be detected employing the same ut probe, which substantially reduces the cost of real-time pcr set-up. in addition, this method could be used for simultane ... | 2003 | 14530456 |
| dual resistance to bacillus thuringiensis cry1ac and cry2aa toxins in heliothis virescens suggests multiple mechanisms of resistance. | one strategy for delaying evolution of resistance to bacillus thuringiensis crystal (cry) endotoxins is the production of multiple cry toxins in each transgenic plant (gene stacking). this strategy relies upon the assumption that simultaneous evolution of resistance to toxins that have different modes of action will be difficult for insect pests. in b. thuringiensis-transgenic (bt) cotton, production of both cry1ac and cry2ab has been proposed to delay resistance of heliothis virescens (tobacco ... | 2003 | 14532042 |
| use of denaturing high-performance liquid chromatography to identify bacillus anthracis by analysis of the 16s-23s rrna interspacer region and gyra gene. | denaturing high-performance liquid chromatography (dhplc) was evaluated as a method for identifying bacillus anthracis by analyzing two chromosomal targets, the 16s-23s intergenic spacer region (isr) and the gyra gene. the 16s-23s isr was analyzed by this method with 42 strains of b. anthracis, 36 strains of bacillus cereus, and 12 strains of bacillus thuringiensis; the gyra gene was analyzed by this method with 33 strains of b. anthracis, 27 strains of b. cereus, and 9 strains of b. thuringiens ... | 2003 | 14532217 |
| a new multiplex pcr for the detection of hbl genes in strains of the 'bacillus cereus group'. | 2003 | 14535496 | |
| identification of two isoforms of aminopeptidase n in aedes aegypti larval midgut. | the bacterium bacillus thuringiensis produces toxin inclusions that are deleterious to target insect larvae. these toxins are believed to interact with a specific receptor protein(s) that is present on the gut epithelial cells of the larvae. in various insect species (in particular those belonging to the lepidopteran class), aminopeptidase n (apn) is one of the two receptor proteins that are considered to be involved in toxin-receptor interactions. however, in mosquitoes, the nature and identity ... | 2003 | 14536036 |
| transgenic loblolly pine (pinus taeda l.) plants expressing a modified delta-endotoxin gene of bacillus thuringiensis with enhanced resistance to dendrolimus punctatus walker and crypyothelea formosicola staud. | a synthetic version of the cry1ac gene of bacillus thuringiensis has been used for the transformation of loblolly pine (pinus taeda l.) using particle bombardment. mature zygotic embryos were used to be bombarded and to generate organogenic callus and transgenic regenerated plants. expression vector pb48.215 dna contained a synthetic bacillus thuringiensis (b.t.) cry1ac coding sequence flanked by the double cauliflower mosaic virus (camv) 35s promoter and nopaline synthase (nos) terminator seque ... | 2003 | 12554726 |
| a delta-endotoxin encoded in pseudomonas fluorescens displays a high degree of insecticidal activity. | the short field-life of bacillus thuringiensis (bt) insecticidal crystal protein has limited its use. when the bt toxin is produced in pseudomonas fluorescens it can be encapsulated and retain its effectiveness for two to three times longer than other bt formulations. in order to improve bt expression, we have synthesized cryia(c) bt delta-endotoxin encoding region (genbank af537267) according to the usage codon of p. fluorescens and transformed the bt toxin expression cassette into p. fluoresce ... | 2003 | 14556036 |
| microbial ecology of bacillus thuringiensis: fecal populations recovered from wildlife in korea. | a total of 34 fecal samples, collected from 14 species of wild mammals in korea, were examined for the occurrence of bacillus thuringiensis. the organism was detected in 18 (53%) samples. among the three food-habit groups, herbivorous animals yielded the highest frequency (69%) of samples positive for b. thuringiensis, followed by omnivorous animals (50%). of the six fecal samples from carnivorous animals, only one sample contained b. thurin giensis. among 527 isolates belonging to the bacillus ... | 2003 | 14569287 |
| [inheritance and segregation of transformants in cotton with two types of insect-resistant genes]. | a plant expression vector containing a chemeric bt29k gene coding for the active cry1ac protein and the arrowhead proteinase inhibition gene api-b was introduced into an elite cotton cultivar jihe 321 by agrobactertium tumefaciens. some insect-resistant cotton lines were developed. segregation and stabilization of insect-resistant genes in six transformation lines were studied. based on the results of kanamycin resistant test and insect bioassay using heliethis armigera, pcr detection and southe ... | 2003 | 14579531 |
| rapid digestion of cry34ab1 and cry35ab1 in simulated gastric fluid. | two genes were identified in bacillus thuringiensis berliner (bt) that code for the proteins that comprise a cry34ab1/cry35ab1 binary insecticidal crystal protein. maize, zea mays l., plants have been transformed to express the cry34ab1/cry35ab1 proteins, and as a result, these plants are resistant to attack by western corn rootworm, diabrotica virgifera virgifera leconte, a major pest in the midwestern corn-growing area of the u.s.a. as part of the safety assessment for the proteins, digestibil ... | 2003 | 14582981 |
| mosquito larvicidal activity of transgenic anabaena pcc 7120 expressing toxin genes from bacillus thuringiensis subsp. israelensis. | genes encoding the mosquito larvicidal toxins cry4aa, cry11aa, cyt1aa and the regulatory p20 from bacillus thuringiensis subsp. israelensis were introduced into the nitrogen-fixing, filamentous cyanobacterium anabaena pcc 7120 for expression under control of two strong promoters p(psba) and p(a1). the clone prve4-adrc displayed toxicity against fourth-instar larvae of aedes aegypti, the highest ever achieved in cyanobacteria. it was about 2.5-fold more toxic than the respective clone without cyt ... | 2003 | 14592708 |
| detection of corn intrinsic and recombinant dna fragments and cry1ab protein in the gastrointestinal contents of pigs fed genetically modified corn bt11. | genetically modified corn has been approved as an animal feed in several countries, but information about the fate of genetically modified dna and protein in vivo is insufficient. genetically modified corn bt11 is developed by inserting a recombinant dna sequence encoding insecticidal cry1ab protein from bacillus thuringiensis subsp. kurstaki. we examined the presence of corn intrinsic and recombinant cry1ab gene by pcr, and the cry1ab protein by immunological tests in the gastrointestinal conte ... | 2003 | 14552382 |
| susceptibility profile of culex quinquefasciatus (diptera: culicidae) to bacillus sphaericus on selection with rotation and mixture of b. sphaericus and b. thuringiensis israelensis. | several strains of bacillus sphaericus (neide) (bsph), a spore-forming bacterium that produces potent mosquitocidal toxins, have been widely used against mosquito larvae globally. in some locations in the field and in the laboratory, moderate to high levels of resistance in culex pipiens complex mosquito larvae to bsph have been reported. practical strategies for dealing with the resistance problem and more importantly to delay or possibly prevent development of resistance to bsph in the first p ... | 2003 | 14596281 |
| transgenic plants expressing two bacillus thuringiensis toxins delay insect resistance evolution. | preventing insect pests from developing resistance to bacillus thuringiensis (bt) toxins produced by transgenic crops is a major challenge for agriculture. theoretical models suggest that plants containing two dissimilar bt toxin genes ('pyramided' plants) have the potential to delay resistance more effectively than single-toxin plants used sequentially or in mosaics. to test these predictions, we developed a unique model system consisting of bt transgenic broccoli plants and the diamondback mot ... | 2003 | 14608363 |
| rapid evolution and the cost of resistance to bacillus thuringiensis in greenhouse populations of cabbage loopers, trichoplusia ni. | the microbial insecticide bacillus thuringiensis (bt) has become the mainstay of non-chemical control of lepidopteran pests, either as sprays or through the incorporation of bt toxins into transgenic crops. given the wide use of bt, it is striking that currently only one pest species, plutella xylostella, has been reported to have developed significant resistance to bt outside the laboratory. by contrast, we report here the frequent and rapid development of resistance to b. thuringiensis kurstak ... | 2003 | 14613613 |
| the bacillus thuringiensis linear double-stranded dna phage bam35, which is highly similar to the bacillus cereus linear plasmid pbclin15, has a prophage state. | bam35, a 15-kbp double-stranded dna phage, infects bacillus thuringiensis. recently, sequencing of the related bacillus cereus revealed a 15.1-kbp linear plasmid, pbclin15. we show that pbclin15 closely resembles bam35 and demonstrate conversion of bam35 to a prophage. this state is common, as several b. thuringiensis strains release bam35-related viruses. | 2003 | 14617663 |
| inheritance of resistance to bt canola in a field-derived population of plutella xylostella. | crops expressing bacillus thuringiensis (bt) insecticidal cry proteins are grown on millions of hectares. recommendations to delay resistance are based on a high expression/refugia strategy that aims to kill resistant heterozygotes and enable some susceptible insects to survive. leaf-dip bioassays on f1 crosses of malaysian populations of diamondback moth (plutella xylostella (l)) showed that crylac resistance was not fully recessive. the survival of ca 50% of heterozygotes on bt canola (brassic ... | 2003 | 14620045 |
| decontamination of bacillus thuringiensis spores on selected surfaces by chlorine dioxide gas. | this work examined the efficacy of chlorine dioxide (clo2) gas for the decontamination of bacillus thuringiensis spores on paper, wood, epoxy, and plastic surfaces. spores representing an inoculation level of approximately 6 log colony-forming units (cfu) per surface were treated with 5, 10, 15, 20, 25, or 30 milligrams per liter (mg/l) clo2 gas for 12 hours under 85-92 percent relative humidity and at 22 +/- 1 degrees c. under the tested treatment conditions, the highest population of surviving ... | 2003 | 14621648 |
| sustainability of insect resistance management strategies for transgenic bt corn. | increasing interest in the responsible management of technology in the industrial and agricultural sectors of the economy has been met thorough the development of broadly applicable tools to assess the "sustainability" of new technologies. an arena ripe for application of such analysis is the deployment of transgenic crops. the new transgenic pesticidal or plant-incorporated protectant (pip) crops have seen widespread application in the united states based on the features of higher yield, lower ... | 2003 | 14623043 |
| cloning and expression of the insecticidal crystal protein gene cry1ca9 of bacillus thuringiensis g10-01a from taiwan granaries. | a new cry gene (cry1ca9) was cloned and sequenced from a bacillus thuringiensis isolate native to taiwan (g10-01a). the cry1c-type gene, designated cry1ca9, consisted of an open reading frame of 3,567 bp, encoding a protein of 1,189 amino acid residues. the polypeptide has the deduced amino acid sequences predicting molecular masses of 134.7 kda. the gene sequence was compared against the genbank nucleotide sequence data base. it was found that the cry1ca9 gene coded for a 134.7-kda protoxin whi ... | 2003 | 14629010 |
| a bacillus thuringiensis isolate possessing a spore-associated filament. | we report on a novel bacterium, isolated during a screen for environmental isolates of bacillus thuringiensis, that possesses a novel filamentous structure. nucleotide sequence from the isolate's 16s rrna gene places the bacterium unambiguously within the bacillus thuringiensis/bacillus cereus group. phase-contrast and electron microscopy indicate the presence of both a parasporal body and a long filament which are retained after sporulation. the filament is shown to consistently arise from the ... | 2003 | 14629020 |
| characterization of a mosquitocidal bacillus thuringiensis serovar sotto strain isolated from okinawa, japan. | to characterize the mosquitocidal activity of parasporal inclusions of the bacillus thuringiensis serovar sotto strain 96-ok-85-24, for comparison with two well-characterized mosquitocidal strains. | 2003 | 14633026 |
| detection and characterization of the novel bacteriocin entomocin 9, and safety evaluation of its producer, bacillus thuringiensis ssp. entomocidus hd9. | to identify and characterize new bacteriocins from a collection of 41 strains belonging to 27 subspecies of bacillus thuringiensis, and to evaluate the safety of the producers. | 2003 | 14633027 |
| bt: mode of action and use. | the insecticidal toxins from bacillus thuringiensis (bt) represent a class of biopesticides that are attractive alternatives to broad-spectrum "hard" chemistries. the u.s. food quality protection act and the european economic council directives aimed at reducing the use of carbamate and organophosphate insecticides were expected to increase the use of narrowly targeted, "soft" compounds like bt. here we summarize the unique mode of action of bt, which contributes to pest selectivity. we also rev ... | 2003 | 14635181 |
| modelling the spatial configuration of refuges for a sustainable control of pests: a case study of bt cotton. | the 'high-dose-refuge' (hdr) strategy is widely recommended by the biotechnology industry and regulatory authorities to delay pest adaptation to transgenic crops that produce bacillus thuringiensis (bt) toxins. this involves cultivating nontoxic plants (refuges) in close proximity to crops producing a high dose of bt toxin. the principal cost associated with this strategy is due to yield losses suffered by farmers growing unprotected, refuge plants. using a population genetic model of selection ... | 2003 | 14635838 |
| a plasmid encoding a combination of mosquito-larvicidal genes from bacillus thuringiensis subsp. israelensis and bacillus sphaericus confers toxicity against a broad range of mosquito larvae when expressed in gram-negative bacteria. | a recombinant plasmid harboring cry4a, cry4b and cry11a from bacillus thuringiensis subsp. israelensis and binary toxin genes from bacillus sphaericus has been constructed. the three cry genes were placed under the control of the cry4b promoter whereas the binary toxin gene was controlled by its native promoter. the expression of toxins in escherichia coli harboring the resulting plasmid, p4bda-5142, was investigated. cry4b expression was highest compared to other toxins. although the level of t ... | 2003 | 14638432 |
| identification of bacterial spores using statistical analysis of fourier transform infrared photoacoustic spectroscopy data. | fourier transform infrared photoacoustic spectroscopy (ftir-pas) has been applied for the first time to the identification and speciation of bacterial spores. a total of forty specimens representing five strains of bacillus spores (bacillus subtilis atcc 49760, bacillus atrophaeus atcc 49337, bacillus subtilis 6051, bacillus thuringiensis subsp. kurstaki, and bacillus globigii dugway) were analyzed. spores were deposited, with minimal preparation, into the photoacoustic sample cup and their spec ... | 2003 | 14661830 |
| compaction of the escherichia coli nucleoid caused by cyt1aa. | compaction of the escherichia coli nucleoid in the cell's centre was associated with the loss of colony-forming ability; these effects were caused by induction of cyt1aa, the cytotoxic 27 kda protein from bacillus thuringiensis subsp. israelensis. cyt1aa-affected compaction of the nucleoids was delayed but eventually more intense than compaction caused by chloramphenicol. the possibility that small, compact nucleoids in cyt1aa-expressing cells resulted in dna replication run-out and segregation ... | 2003 | 14663087 |
| effect of sm(3+) ion on growth of bacillus thuringiensis by microcalorimetry. | by using an lkb-2277 bioactivity monitor, cycle-flow method, the thermogenic curves of aerobic growth for bacillus thuringiensis cry ii strain at 28 degrees c have been obtained. the metabolic thermogenic curves of b. thuringiensis cry ii contained two distinct patterns: the first reflects the changes during the bacterial growth phase and the second corresponds to the sporulation phase. from these thermogenic curves in the absence and presence of sm(3+) ions, the thermokinetic parameters such as ... | 2003 | 14665732 |
| [potential of bacillus thuringiensis israelensis berliner for controlling aedes aegypti]. | the importance of the entomopathogenic bacterium bacillus thuringiensis israelensis in the control of aedes aegypti is presented. the use and potential of b. thuringiensis israelensis against the mosquito vector of dengue fever is described. other aspects such as insect's resistance development against chemicals and advantages and constraints of using microbial control are discussed. emphasis is given to the importance of the use of this bacterium in brazil, which could contribute significantly ... | 2003 | 14666315 |
| effect of food processing on the fate of dna with regard to degradation and transformation capability in bacillus subtilis. | soymilk, tofu, corn masa, and cooked potato were produced from transgenic raw materials and the effect of processing on the degradation of dna was studied. major degrading factors were for soymilk and tofu the mechanical treatment of soaked soybeans and for corn masa and cooked potatoes the thermal treatment. in the processed foods no dna fragments > 1.1 kb were detected. we included in our studies the effect of the size of donor dna and length of the homologous sequence on the marker rescue tra ... | 2003 | 14666975 |
| cry29a and cry30a: two novel delta-endotoxins isolated from bacillus thuringiensis serovar medellin. | two novel crystal protein genes from a highly mosquitocidal bacillus thuringiensis serovar medellin strain were cloned and sequenced. the corresponding proteins, cry29a and cry30a, were nontoxic when tested individually against the mosquito species bioassayed (aedes aegypti, culex pipiens and anopheles stephensi). however, cry29a synergized the toxicity of cry11bb against aedes aegypti by a four-fold factor. | 2003 | 14666976 |
| sequencing and characterization of plasmid puibi-1 from bacillus thuringiensis serovar entomocidus lbit-113. | plasmid puibi-1 from bacillus thuringiensis svr. entomocidus was sequenced and its replication mechanism analyzed. sequence analysis revealed that puibi-1 contains 4671 bp and a 32% gc content. plasmid puibi-1 also includes at least seven putative open reading frames (orfs) encoding for proteins ranging from 5 to 50 kda. orf-1 encodes for a putative 16-kda rep protein, which lacks homology with proteins of similar function. orf2 encodes for a protein of 50 kda and shows homology with mob protein ... | 2003 | 14669916 |
| distribution analysis of is231-like sequences among bacillus thuringiensis serovars inferred from restriction fragment length polymorphisms. | the distribution of is231 has been analyzed in bacillus thuringiensis serovars. a 723-bp haeii conserved fragment from is231m has been used as a probe against ecori-digested b. thuringiensis total dna to yield serovar-specific hybridization profiles. the approach was useful at revealing the extent of distribution of is231-like sequences between and within strains. of the 88 b. thuringiensis strains tested, 70 showed hybridization banding patterns that comprised between one and 20 distinct bands. ... | 2003 | 14669921 |
| [on the adaptive nature of the dissociation process in bacillus thuringiensis]. | the process of dissociation into variants differing in colony morphology occurring in batch cloned cultures of two bacillus thuringiensis strains belonging to different subspecies was studied at optimal and elevated temperatures. an increase in the cultivation temperature to 40 degrees c resulted in an increase in the fraction of r variants to 100% after 72 h of cultivation of either of the strains. this increase was not due to the selection of forms with greater resistance to elevated temperatu ... | 2003 | 14679909 |
| the ispa protease's involvement in the regulation of the sporulation process of bacillus thuringiensis is revealed by proteomic analysis. | we have observed that the process of sporulation of the ispa-deficient mutant was delayed under phase-contrast microscopy. the protein profiles of the ispa-deficient mutant have been analyzed using two-dimensional gel electrophoresis. the results of a proteomic analysis using maldi-tof ms indicated that a sporulation-associated protein, pro- [formula: see text], was upregulated, while two other sporulation-associated proteins, spovd and spovr, were downregulated in the ispa-deficient mutant. it ... | 2003 | 14680823 |
| [construction of insecticidal recombinant bacillus thuringiensis using an integrative vector]. | insecticidal crystal protein gene cry1c which is highly toxic to spodoptera exigua was cloned into an integrative vector pbmb-f7e, which was derived from bacillus thuringiensis transposon tn4430. the recombinant integrative plasmid pbmb-flc harboring the cry1c gene was gained and transformed into a wild-type bt strain ybt803-1. a transformant bmb803-a was obtained, and grown at 46 degrees c for about 120 generations, from which three recombinants with cry1c gene integrating into the chromosome w ... | 2003 | 14682242 |
| leaf ontogeny influences leaf phenolics and the efficacy of genetically expressed bacillus thuringiensis cry1a(a) d-endotoxin in hybrid poplar against gypsy moth. | we tested the hypothesis that ontogenetic variation in leaf chemistry could affect the efficacy of genetically expressed bacillus thuringiensis cry1a(a) d-endotoxin, and thus provide spatial variation in (1) foliage protection and (2) selective pressures that could delay the resistance of folivores. our model consisted of clonal hybrid populus plants (nc5339). consumption of foliage and relative growth rates of gypsy moth, lymantria dispar (l.) increased, and phenolic glycoside concentrations de ... | 2003 | 14682535 |
| production of biopesticides using wastewater sludge as a raw material--effect of process parameters. | production of bacillus thuringiensis (bt) based biopesticide was studied using hydrolysed or raw wastewater sludge as a raw material. the sludge hydrolysis was carried out at different ph (2, 4 and 6). the sludge after hydrolysis was sterilised at 121 degrees c for 30 minutes. the effect of temperature, ph and agitation speed on growth and toxin production was also investigated. the ph in the shake flask was controlled by adding 0.1 m tris buffer. the progress of the biopesticide production proc ... | 2003 | 14682592 |
| bt-resistance management--theory meets data. | 2003 | 14647327 |