Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| binding analyses of bacillus thuringiensis cry delta-endotoxins using brush border membrane vesicles of ostrinia nubilalis. | transgenic corn expressing the bacillus thuringiensis cry1ab gene is highly insecticidal to ostrinia nubilalis (european corn borer) larvae. we ascertained whether cry1f, cry9c, or cry9e recognizes the cry1ab binding site on the o. nubilalis brush border by three approaches. an optical biosensor technology based on surface plasmon resonance measured binding of brush border membrane vesicles (bbmv) injected over a surface of immobilized cry toxin. preincubation with cry1ab reduced bbmv binding to ... | 2001 | 11157257 |
| portable system for microbial sample preparation and oligonucleotide microarray analysis. | we have developed a three-component system for microbial identification that consists of (i) a universal syringe-operated silica minicolumn for successive dna and rna isolation, fractionation, fragmentation, fluorescent labeling, and removal of excess free label and short oligonucleotides; (ii) microarrays of immobilized oligonucleotide probes for 16s rrna identification; and (iii) a portable battery-powered device for imaging the hybridization of fluorescently labeled rna fragments with the arr ... | 2001 | 11157263 |
| mannose phosphate isomerase isoenzymes in plutella xylostella support common genetic bases of resistance to bacillus thuringiensis toxins in llpidopteran species. | a strong correlation between two mannose phosphate isomerase (mpi) isoenzymes and resistance to cry1a toxins from bacillus thuringiensis has been found in a plutella xylostella population. mpi linkage to cry1a resistance had previously been reported for a heliothis virescens population. the fact that the two populations share similar biochemical, genetic, and cross-resistance profiles of resistance suggests the occurrence of homologous resistance loci in both species. | 2001 | 11157273 |
| the mammalian safety of bacillus thuringiensis-based insecticides. | the united states environmental protection agency between the years 1961 and 1995 registered 177 products containing viable bacillus thuringiensis (bt). numerous laboratory studies have demonstrated that bt and bt products are noninfectious and are toxic to mammals only at a dose > or =10(8) colony forming units (cfu) per mouse (a human equivalent based on the weight of >10(11) cfu). in contrast, as few as three vegetative cells of bacillus anthracis can kill mice (a human equivalent of >10(3) c ... | 2001 | 11161988 |
| why bacillus thuringiensis insecticidal toxins are so effective: unique features of their mode of action. | the spore-forming bacterium bacillus thuringiensis produces intracellular inclusions comprised of protoxins active on several orders of insects. these highly effective and specific toxins have great potential in agriculture and for the control of disease-related insect vectors. inclusions ingested by larvae are solubilized and converted to active toxins in the midgut. there are two major classes, the cytolytic toxins and the delta-endotoxins. the former are produced by b. thuringiensis subspecie ... | 2001 | 11166987 |
| the ptsh gene from bacillus thuringiensis israelensis. characterization of a new phosphorylation site on the protein hpr. | the ptsh gene from bacillus thuringiensis israelensis (bti), coding for the phosphocarrier protein hpr of the phosphotransferase system has been cloned and overexpressed in escherichia coli. comparison of its primary sequence with other hpr sequences revealed that the conserved his15 and ser46 residues were shifted by one amino acid and located at positions 14 and 45, respectively. the biological activity of the protein was not affected by this change. when expressed in a bacillus subtilis ptsh ... | 2001 | 11168390 |
| spatial and temporal distribution of airborne bacillus thuringiensis var. kurstaki during an aerial spray program for gypsy moth eradication. | we measured airborne exposures to the biological insecticide bacillus thuringiensis var. kurstaki (btk) during an aerial spray program to eradicate gypsy moths on the west coast of canada. we aimed to determine whether staying indoors during spraying reduced exposures, to determine the rate of temporal decay of airborne concentrations, and to determine whether drift occurred outside the spray zone. during spraying, the average culturable airborne btk concentration measured outdoors within the sp ... | 2001 | 11171524 |
| the role of a proline-induced broken-helix motif in alpha-helix 2 of bacillus thuringiensis delta-endotoxins. | bacillus thuringiensis delta-endotoxins (cry proteins), are widely used for insect control and plant protection. they are water-soluble proteins that insert into membranes forming ion channels. in most cry toxins alpha-helix 2 is broken by a highly conserved proline residue (pro70 in cry1ab), generating a broken-helix motif. the flexibility of the motif was altered through site-directed mutagenesis. it was found that increasing the flexibility of the motif decreased the stability, the ion transp ... | 2001 | 11172813 |
| cultivation of bacillus thuringiensis in an airlift reactor with wire mesh draft tubes. | an aeration strategy was proposed for foam control in an airlift reactor with double wire mesh draft tubes. the airlift reactor was employed in the cultivation of bacillus thuringiensis for thuringiensin production. the aeration strategy involved two situations. if the foam rose and touched the foam probe, the air flow rate was dropped to a low value for a certain period. however, if the do value was already below 10% of the saturation when the air flow rate was dropped, the conventional foam co ... | 2001 | 11150794 |
| phylogenetic analysis of bacillus thuringiensis serovars based on 16s rrna gene restriction fragment length polymorphisms. | to determine the 16s rrna gene fingerprints of bacillus thuringiensis strains to reveal phylogenetic relationships among them. | 2001 | 11155130 |
| detection of enterotoxic bacillus cereus and bacillus thuringiensis strains by pcr analysis. | many strains of bacillus cereus cause gastrointestinal diseases, and the closely related insect pathogen b. thuringiensis has also been involved in outbreaks of diarrhea. the diarrheal types of diseases are attributed to enterotoxins. two different enterotoxic protein complexes, hemolysin bl (hbl) and nonhemolytic enterotoxin (nhe), and an enterotoxic protein, enterotoxin t, have been characterized, and the genes have been sequenced. pcr primers for the detection of these genes were deduced and ... | 2001 | 11133444 |
| importance of cry1 delta-endotoxin domain ii loops for binding specificity in heliothis virescens (l.). | we constructed a model for bacillus thuringiensis cry1 toxin binding to midgut membrane vesicles from heliothis virescens. brush border membrane vesicle binding assays were performed with five cry1 toxins that share homologies in domain ii loops. cry1ab, cry1ac, cry1ja, and cry1fa competed with (125)i-cry1aa, evidence that each toxin binds to the cry1aa binding site in h. virescens. cry1ac competed with high affinity (competition constant [k(com)] = 1.1 nm) for (125)i-cry1ab binding sites. cry1a ... | 2001 | 11133462 |
| plasmid transfer between bacillus thuringiensis subsp. israelensis strains in laboratory culture, river water, and dipteran larvae. | plasmid transfer between strains of bacillus thuringiensis subsp. israelensis was studied under a range of environmentally relevant laboratory conditions in vitro, in river water, and in mosquito larvae. mobilization of pbc16 was detected in vitro at a range of temperatures, ph values, and available water conditions, and the maximum transfer ratio was 10(-3) transconjugant per recipient under optimal conditions. transfer of conjugative plasmid pxo16::tn5401 was also detected under this range of ... | 2001 | 11133463 |
| cyt1a from bacillus thuringiensis lacks toxicity to susceptible and resistant larvae of diamondback moth (plutella xylostella) and pink bollworm (pectinophora gossypiella). | we tested cyt1aa, a cytolytic endotoxin of bacillus thuringiensis, against susceptible and cry1a-resistant larvae of two lepidopteran pests, diamondback moth (plutella xylostella) and pink bollworm (pectinophora gossypiella). unlike previous results obtained with mosquito and beetle larvae, cyt1aa alone or in combination with cry toxins was not highly toxic to the lepidopteran larvae that we examined. | 2001 | 11133481 |
| overexpression of the bt cry2aa2 operon in chloroplasts leads to formation of insecticidal crystals. | in nuclear transgenic plants, expression of multiple genes requires introduction of individual genes and time-consuming subsequent backcrosses to reconstitute multi-subunit proteins or pathways, a problem that is compounded by variable expression levels. in order to accomplish expression of multiple genes in a single transformation event, we have introduced several genes into the chromoplast genome. we confirmed stable integration of the cry2aa2 operon by pcr and southern blot analyses in t(0) a ... | 2001 | 11135556 |
| pcr analysis of cry7 genes in bacillus thuringiensis by the five conserved blocks of toxins. | an alternative pcr analysis to screen for cry7 genes is proposed, based on the five conserved blocks of amino acids of bacillus thuringiensis toxins and their encoding dna sequences. a complete set of five primers was constructed, four direct and one reverse, yielding four specific amplicons. modified profiles can identify new cry genes. | 2001 | 11136129 |
| two delta-endotoxin genes, cry9da and a novel related gene, commonly occurring in lepidoptera-specific bacillus thuringiensis japanese isolates that produce spherical parasporal inclusions. | six lepidoptera-specific bacillus thuringiensis isolates, which belong to the four h serovars (sotto, fukuokaensis, canadensis, and galleriae) and produce spherical parasporal inclusions, were examined for assignment of the classes of the delta-endotoxin genes. gene analysis was conducted by pcr technique with primers designed to probe the genes cry9ca and cry9da. the data revealed that the delta-endotoxin of a serovar canadensis isolate is encoded by the gene cry9da, while those of the five oth ... | 2001 | 11136135 |
| a 28 kda protein of the bacillus thuringiensis serovar shandongiensis isolate 89-t-34-22 induces a human leukemic cell-specific cytotoxicity. | a 28 kda protein that exhibits cytocidal activity specific for human leukemic t (molt-4) cells was purified from proteinase k-digested parasporal inclusion of a bacillus thuringiensis serovar shandongiensis isolate. the n-terminal sequence of the protein was identical with that of the 32 kda protein, regarded as a protoxin, of the inclusion proteins. the median effective concentration of this protein was 0.23 microg/ml against molt-4 cells and its specific activity was 7.9 times greater than tha ... | 2001 | 11343791 |
| will genetically modified foods be allergenic? | foods produced through agricultural biotechnology, including such staples as corn, soybeans, canola, and potatoes, are already reaching the consumer marketplace. agricultural biotechnology offers the promise to produce crops with improved agronomic characteristics (eg, insect resistance, herbicide tolerance, disease resistance, and climatic tolerance) and enhanced consumer benefits (eg, better taste and texture, longer shelf life, and more nutritious). certainly, the products of agricultural bio ... | 2001 | 11344340 |
| recovery of commercially produced bacillus thuringiensis var. israelensis and bacillus sphaericus from tires and prevalence of bacilli in artificial and natural containers. | we conducted surveys to identify the species of spore-forming bacteria present in natural and artificial containers. most of our samples came from illinois. identification was based on the cellular fatty acid composition of the bacterial cell wall. in addition, we utilized a custom database for commercially produced strains of bacillus thuringiensis var. israelensis (bti) and b. sphaericus, to differentiate between larvicidal isolates with commercial or native origin. native bti was present at l ... | 2001 | 11345416 |
| evaluation of liquid bacillus thuringiensis var. israelensis products for control of australian aedes arbovirus vectors. | laboratory bioassay studies were conducted in southeast queensland, australia, on the efficacy of teknar, vectobac 12as, and cybate (active ingredient: 1,200 international toxic units bacillus thuringiensis var. israelensis [bti]) against 3rd instars of the arbovirus vectors aedes aegypti, ae. notoscriptus, ae. vigilax, and ae. camptorhynchus. probit analyses were then used to determine ld50 (median lethal dose), ld50, and lethal dose ratios (ldr). aedes aegypti and ae. notoscriptus, both contai ... | 2001 | 11345425 |
| diamondback moth compensatory consumption of protease inhibitor-transformed plants. | prior study of the effect of protease inhibitors (pis) on diamondback moths suggests that moths are resistant to them, so pis represent an ineffective defence against moths. however, our data suggest that diamondback moths do suffer lower growth rates when they consume plants transformed with potato protease inhibitor (pi2), but that effect is hidden by compensatory consumption. plants, instead of gaining an advantage by lowering the insect growth rate, suffer a disadvantage as moths consume mor ... | 2001 | 11348512 |
| development of a self floating slow release formulation of bacillus thuringiensis var. israelensis and its larvicidal activity. | alginate encapsulated b. thuringiensis var. israelensis (b. t. i.) self floating type formulations were prepared. its spore release rate, floating efficacy and larvicidal activity against culex quinquefasiatus were tested in the laboratory. the larval mortality of 91-100% was induced by the floating formulation with a mean spore release of 3.04 x 10(4)/ml/day from 6th day to 27th day. from day 28 to 33 the mean number of spores released were 1.16 x 10(4)/ml/day which caused 72.2-88.2% mortality. ... | 2001 | 11349533 |
| mortality of colorado potato beetle (leptinotarsa decemlineata) after sublethal stress with the cryiiia delta-endotoxin of bacillus thuringiensis and subsequent exposure to beauveria bassiana. | acute or chronic sublethal exposure of colorado potato beetle larvae to the cryiiia delta-endotoxin of bacillus thuringiensis berliner did not significantly (p > 0.05) alter their subsequent susceptibility to beauveria bassiana (balsamo) vuillemin. during the period of exposure to b. bassiana there was continued mortality from previous exposure to delta-endotoxin, and b. bassiana also caused significant mortality. acute and chronic exposure to delta-endotoxin significantly prolonged larval devel ... | 2001 | 11356052 |
| prospects for reducing fumonisin contamination of maize through genetic modification. | fumonisins (fb) are mycotoxins found in (italic)fusarium verticillioides-infected maize grain worldwide. attention has focused on fbs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. fbs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. among the strategies for reducing risk of fb contamination in maize supplied to the market, developme ... | 2001 | 11359705 |
| transformation studies of bacillus thuringiensis cryic gene into a nitrogen-fixing azospirillum lipoferum. | a lepidopteran toxin gene, cryic (psb607) from entomopathogenic bacillus thuringiensis subsp. aizawai was introduced into nitrogen-fixing azospirillum lipoferum by transformation. regeneration of spheroplasts was achieved at 99% with 39% frequency of regeneration. transformants were screened on nb kanamycin with ampicillin plates and 4 transformants were selected after ten generations. sds-page and western blot analysis confirmed the presence of a 68 kda protein in the transformants. studies on ... | 2001 | 11371015 |
| cross-resistance and inheritance of resistance to bacillus thuringiensis toxin cry1ac in diamondback moth (plutella xylostella l) from lowland malaysia. | a field population of plutella xylostella from malaysia (serd4) was divided into five sub-populations and four were selected (g2-g5) with the bacillus thuringiensis insecticidal crystal (cry) toxins cry1ac, cry1ab, cry1ca and cry1da. bioassay at g6 gave resistance ratios of 88, 5, 2 and 3 for cry1ac, cry1ab, cry1ca and cry1da respectively compared with the unselected sub-population (unsel-serd4). the cry1ac-selected population showed little cross-resistance to cry1ab, cry1ca and cry1da, (3-, 2- ... | 2001 | 11374157 |
| exchange of domain i from bacillus thuringiensis cry1 toxins influences protoxin stability and crystal formation. | influence of domain i exchange on the stability and production of bacillus thuringiensis cry1 protoxins as well as on the shape of inclusion and toxicity to spodoptera exigua and plutella xylostella larvae was investigated. chimeric genes were prepared by exchanging the regions coding for domain i between cry1aa, cry1ab, cry1ac, cry1c, and cry1e. the accc chimera accumulated into bipyramidal inclusion bodies, whereas cee produced round-shaped inclusion bodies, and ecc and aaee protoxins produced ... | 2001 | 11375655 |
| cloning and expression of the binary toxin gene from bacillus sphaericus iab872 in a crystal-minus bacillus thuringiensis subsp. israelensis. | bacillus sphaericus iab872 has high toxicity against susceptible culex spp. and medium larvicidal activity against binary toxin-resistant culex spp. sequence analysis revealed that the sequence of the binary toxin gene from iab872 was totally identical to that of the reference strain 2362. the recombinant plasmids were introduced into an acrystalliferous b. thuringiensis strain 4q7, and the resulting transformants produced parasporal inclusion composed of 51 kda and 42 kda proteins during sporul ... | 2001 | 11375659 |
| structure of cry2aa suggests an unexpected receptor binding epitope. | genetically modified (gm) crops that express insecticidal protein toxins are an integral part of modern agriculture. proteins produced by bacillus thuringiensis (bt) during sporulation mediate the pathogenicity of bt toward a spectrum of insect larvae whose breadth depends upon the bt strain. these transmembrane channel-forming toxins are stored in bt as crystalline inclusions called cry proteins. these proteins are the active agents used in the majority of biorational pesticides and insect-resi ... | 2001 | 11377201 |
| mutations at the arginine residues in alpha8 loop of bacillus thuringiensis delta-endotoxin cry1ac affect toxicity and binding to manduca sexta and lymantria dispar aminopeptidase n. | the functional role of the alpha8 loop residues in domain ii of bacillus thuringiensis cry1ac toxin was examined. alanine substitution mutations were introduced in the residues from 275 to 293. among the mutant toxins, substitutions at r281 and r289 affected toxicity to manduca sexta and lymantria dispar. loss of toxicity by these mutant toxins was well correlated with reductions in binding affinity for brush border membrane vesicles and the purified receptor, aminopeptidase n (apn), from both i ... | 2001 | 11377423 |
| cellular localization and characterization of the bacillus thuringiensis orf2 crystallization factor. | in vivo crystallization of the bacillus thuringiensis insecticidal protein toxin cry2aa has been studied in the presence and absence of its associated crystallization factor orf2. when expressed in the same cell, both proteins were localized to the cuboidal cytoplasmic crystal. when expressed in the absence of cry2aa, orf2 was randomly distributed throughout the cytoplasm. cry2aa when expressed in the absence of orf2 did not form visible crystals but could be recovered from the insoluble fractio ... | 2001 | 11381328 |
| bacillus thuringiensis: a common member of microflora in activated sludges of a sewage treatment plant. | bacillus thuringiensis was recovered at a high frequency from activated-sludge system environments in an urban sewage-digestive plant. all of the test materials, sampled at several digesting steps, contained the organism. of 515 colonies belonging to the b. cereus/b. thuringiensis group, 45 (8.7%) were assigned to b. thuringiensis. the highest density of this bacterium was 1.6 x 103 cfu/ml in a scum sample of the first aeration basin. among the 45 isolates, 7 were assigned to the known h serovar ... | 2001 | 11381335 |
| mapping the epitope in cadherin-like receptors involved in bacillus thuringiensis cry1a toxin interaction using phage display. | in susceptible lepidopteran insects, aminopeptidase n and cadherin-like proteins are the putative receptors for bacillus thuringiensis (bt) toxins. using phage display, we identified a key epitope that is involved in toxin-receptor interaction. three different scfv molecules that bind cry1ab toxin were obtained, and these scfv proteins have different amino acid sequences in the complementary determinant region 3 (cdr3). binding analysis of these scfv molecules to different members of the cry1a t ... | 2001 | 11384982 |
| expression in spodoptera frugiperda (sf21) insect cells of bt-r(1), a cadherin-related receptor from manduca sexta for bacillus thuringiensis cry1ab toxin. | the cadherin-related receptor of manduca sexta, bt-r(1), for the cry1a family of bacillus thuringiensis insecticidal toxins, was expressed in cultured spodoptera frugiperda (sf21) insect cells utilizing the expression vector deltaop-gp64. recombinant bt-r(1) was released by the sf21 cells in soluble form into the culture medium and represents approximately 58% of total bt-r(1) produced by the cells. the soluble protein was purified by affinity chromatography using cry1ab toxin coupled to sepharo ... | 2001 | 11388812 |
| highly toxic and broad-spectrum insecticidal bacillus thuringiensis engineered by using the transposon tn917 and protoplast fusion. | the chromosome of the bacillus thuringiensis strain s184 that was toxic against the third instar larvae of spodoptera litura with the lc(50) of 9.74 microg/ml was successfully integrated into two genes of cyt1aa and cry11aa using the transposon tn917, yielding the primary engineered strain tnx. the strain tnx was highly toxic to the third instar larvae of culex pipiens fatigans with the lc(50) of 5.12 ng/ml which was 1.82-fold higher than that of b. thuringiensis subsp. israelensis, but lowly to ... | 2001 | 11391474 |
| comparative sensitivity to uv-b radiation of two bacillus thuringiensis subspecies and other bacillus sp. | susceptibility of bacillus thuringiensis spores and toxins to the uv-b range (280--330 nm) of the solar spectrum reaching earth's surface may be responsible for its inactivation and low persistence in nature. spores of the mosquito larvicidal b. thuringiensis subsp. israelensis were significantly more resistant to uv-b than spores of the lepidopteran-active subsp. kurstaki. spores of subsp. israelensis were as resistant to uv-b as spores of b. subtilis and more resistant than spores of the close ... | 2001 | 11391479 |
| discrimination between bacterial spore types using time-of-flight mass spectrometry and matrix-free infrared laser desorption and ionization. | we demonstrate that molecular ions with mass-to-charge ratios (m/z) ranging from a few hundred to 19 050 can be desorbed from whole bacterial spores using infrared laser desorption and no chemical matrix. we have measured the mass of these ions using time-of-flight mass spectrometry and we observe that different ions are desorbed from spores of bacillus cereus, bacillus thuringiensis, bacillus subtilis, and bacillus niger. our results raise the possibility of identifying microorganisms using mas ... | 2001 | 11393860 |
| cloning and nucleotide sequence of a new insertion sequence, is231n, from a non-serotypable strain of bacillus thuringiensis. | a new is231 variant, is231n, has been isolated from an autoagglutinable, non-serotypable strain of b. thuringiensis. is231n is 1654 bp in length and is delimited by two incomplete 20-bp inverted repeats (irl and irr) with two mismatches. no direct repeats (drs) were found at the right and left borders of is231n. surprisingly, is231n contains three open reading frames (orfs) that could code for polypeptides of 329 (orf1), 118 (orf2), and 17 (orf3) amino acids, respectively. is231n lacks the 5th c ... | 2001 | 11400069 |
| oligopeptide permease is required for expression of the bacillus thuringiensis plcr regulon and for virulence. | plcr is a pleiotropic regulator of virulence factors in the insect pathogen bacillus thuringiensis and in the opportunistic human pathogen bacillus cereus. it activates the transcription of at least 15 genes encoding extracellular proteins, including phospholipases c, proteases and enterotoxins. expression of the plcr gene is autoregulated and activated at the onset of stationary phase. here, we used mini-tn10 transposition to generate a library of b. thuringiensis mutants, with the goal of char ... | 2001 | 11401703 |
| assessment of toxic potential of local jordanian bacillus thuringiensis strains on drosophila melanogaster and culex sp. (diptera). | to assess the toxic potential of different local jordanian bacillus thuringiensis isolates on larvae of drosophila melanogaster and culex sp. | 2001 | 11412316 |
| source-sink dynamics between transgenic and non-transgenic habitats and their role in the evolution of resistance. | the interaction of population dynamics and movement among two habitat types (toxic transgenic fields and nontoxic refuge fields) on the evolution of insecticide resistance was examined in two different simulation models. the two models were developed to test the hypothesis that increasing habitat grain from fine-grained to coarse-grained, and the resultant increase in nonrandom mating, would increase the rate of local adaptation, here the evolution of resistance. the first model, a complex, stoc ... | 2001 | 11425026 |
| effect of planting dates and bacillus thuringiensis corn on the population dynamics of european corn borer (lepidoptera: crambidae). | field studies were conducted to determine how field corn, zea mays l., phenologies in combination with transgenic bacillus thuringiensis berliner (bt) corn and non-bt (near isogenic) corn could affect egg laying by female european corn borer, ostrinia nubilalis (hubner), and subsequent larval injury. transgenic bt (events 176 and bt11) and non-bt corn was planted at three different times to assess the use of early- and late- planted bt corn as a means for egg recruitment to these targeted planti ... | 2001 | 11425031 |
| impact of bt cottons expressing one or two insecticidal proteins of bacillus thuringiensis berliner on growth and survival of noctuid (lepidoptera) larvae. | a series of laboratory assays were performed to compare the relative impact of commercial and experimental cultivars of cotton, gossypium hirsutum (l.), expressing zero, one, or two insecticidal proteins of bacillus thuringiensis berliner, on several lepidopteran pests. assays in which larvae were fed fresh plant tissue indicated that dual-toxin b. thuringiensis (bt) cultivars, expressing both cry1ac and cry2ab endotoxins of b. thuringiensis, were more toxic to bollworms, helicoverpa zea (boddie ... | 2001 | 11425033 |
| expression of the p20 gene from bacillus thuringiensis h-14 increases cry11a toxin production and enhances mosquito-larvicidal activity in recombinant gram-negative bacteria. | experimental analyses with recombinant escherichia coli and pseudomonas putida transformed with plasmids bearing genes coding for the cry11a toxin and p20 protein from bacillus thuringiensis h-14 showed that cells producing both proteins were more toxic when fed to third-instar aedes aegypti larvae than were cells expressing cry11a alone; the 50% lethal concentrations were in the range of 10(4) to 10(5) cells/ml. western blots revealed a higher production of cry11a when the p20 gene was coexpres ... | 2001 | 11425714 |
| cross-resistance and stability of resistance to bacillus thuringiensis toxin cry1c in diamondback moth. | we tested toxins of bacillus thuringiensis against larvae from susceptible, cry1c-resistant, and cry1a-resistant strains of diamondback moth (plutella xylostella). the cry1c-resistant strain, which was derived from a field population that had evolved resistance to b. thuringiensis subsp. kurstaki and b. thuringiensis subsp. aizawai, was selected repeatedly with cry1c in the laboratory. the cry1c-resistant strain had strong cross-resistance to cry1ab, cry1ac, and cry1f, low to moderate cross-resi ... | 2001 | 11425744 |
| cyt1ab1 and cyt2ba1 from bacillus thuringiensis subsp. medellin and b. thuringiensis subsp. israelensis synergize bacillus sphaericus against aedes aegypti and resistant culex quinquefasciatus (diptera: culicidae). | the interaction of two cytolytic toxins, cyt1ab from bacillus thuringiensis subsp. medellin and cyt2ba from bacillus thuringiensis subsp. israelensis, with bacillus sphaericus was evaluated against susceptible and resistant culex quinquefasciatus and the nonsensitive species aedes aegypti. mixtures of b. sphaericus with either cytolytic toxin were synergistic, and b. sphaericus resistance in c. quinquefasciatus was suppressed from >17,000- to 2-fold with a 3:1 mixture of b. sphaericus and cyt1ab ... | 2001 | 11425753 |
| identification of genes involved in the activation of the bacillus thuringiensis inha metalloprotease gene at the onset of sporulation. | the immune inhibitor a (inha) metalloprotease from bacillus thuringiensis specifically cleaves antibacterial proteins produced by the insect host, suggesting that it may contribute to the overall virulence of b. thuringiensis. the transcriptional regulation of the inha gene in both b. thuringiensis and bacillus subtilis was investigated. using a transcriptional inha'-lacz fusion, it was shown that inha expression is activated at the onset of sporulation. however, the transcriptional start site o ... | 2001 | 11429458 |
| india blocks sale of transgenic cotton seeds. | 2001 | 11429564 | |
| crafting crop resistance to corn rootworms. | 2001 | 11433270 | |
| insecticidal proteins from bacillus thuringiensis protect corn from corn rootworms. | field tests of corn co-expressing two new delta-endotoxins from bacillus thuringiensis (bt) have demonstrated protection from root damage by western corn rootworm (diabrotica virgifera virgifera leconte). the level of protection exceeds that provided by chemical insecticides. in the bacterium, these proteins form crystals during the sporulation phase of the growth cycle, are encoded by a single operon, and have molecular masses of 14 kda and 44 kda. corn rootworm larvae fed on corn roots express ... | 2001 | 11433280 |
| mode of action of bacillus thuringiensis ps86q3 strain in hymenopteran forest pests. | the mode of action of cry toxins has been described principally in lepidopteran insects as a multistep process. in this work we describe the mode of action of a cry toxin active in the common pine sawfly diprion pini (hymenoptera, diprionidae), considered a major forest pest in europe. strain ps86q3 contains a long bipyramidal crystal composed of five major proteins. the n-terminal sequence shows that the 155 kda protein corresponds to cry5b toxin and the other proteins belong to the cry5a subgr ... | 2001 | 11439244 |
| bacillus thuringiensis cry1ac and cry1fa delta-endotoxin binding to a novel 110 kda aminopeptidase in heliothis virescens is not n-acetylgalactosamine mediated. | we determined that bacillus thuringiensis cry1ac and cry1fa delta-endotoxins recognize the same 110, 120 and 170 kda aminopeptidase n (apn) molecules in brush border membrane vesicles (bbmv) from heliothis virescens. the 110 kda protein, not previously identified as an apn, contained a variant apn consensus sequence identical to that found in helicoverpa punctigera apn 2. pcr amplification of h. virescens cdna based on this sequence and a conserved apn motif yielded a 0.9 kb product that has 89% ... | 2001 | 11439250 |
| genetic diversity of bacillus thuringiensis serovars revealed by rflp using random dna probes. | ecori and hindiii restriction fragment length polymorphism (rflp) profiles using 2 random dna probes, named 104 and 106, were generated for 85 b. thuringiensis strains. these include 80 serovars, 4 intra-serovar strains: kurstaki hd-1, dendrolimus, tenebrionis and sandiego, and a non-serotypeable strain b. thuringiensis var. wuhanensis. a total of 47 ecori and 65 hindiii restriction patterns were generated when hybridization results from both probes were combined. seventy-seven b. thuringiensis ... | 2001 | 11441463 |
| reversing insect adaptation to transgenic insecticidal plants. | the refuge-high-dose strategy for delaying insect adaptation to transgenic plants produces non-transgenic plants that enable survival of susceptible individuals. previous theoretical work has suggested three requirements for success of the refuge-high-dose strategy: a low initial frequency of the resistance allele, extensive mating between resistant and susceptible adults and recessive inheritance of resistance. in order to understand an observed decrease in resistance frequency and improve the ... | 2001 | 11454291 |
| role of interdomain salt bridges in the pore-forming ability of the bacillus thuringiensis toxins cry1aa and cry1ac. | the four salt bridges (asp(222)-arg(281), arg(233)-glu(288), arg(234)-glu(274), and asp(242)-arg(265)) linking domains i and ii in cry1aa were abolished individually in alpha-helix 7 mutants d222a, r233a, r234a, and d242a. two additional mutants targeting the fourth salt bridge (r265a) and the double mutant (d242a/r265a) were rapidly degraded during trypsin activation. mutations were also introduced in the corresponding cry1ac salt bridge (d242e, d242k, d242n, and d242p), but only d242n and d242 ... | 2001 | 11466307 |
| structure of the insecticidal bacterial delta-endotoxin cry3bb1 of bacillus thuringiensis. | the coleopteran-active delta-endotoxin cry3bb1 from bacillus thuringiensis (bt) strain eg7231 is uniquely toxic to diabrotica undecimpunctata, the southern corn rootworm, while retaining activity against leptinotarsa decemlineata, the colorado potato beetle. the crystal structure of the delta-endotoxin cry3bb1 has been refined using data collected to 2.4 a resolution, with a residual r factor of 17.5% and an r(free) of 25.3%. the structure is made up of three domains: i, a seven-helix bundle (re ... | 2001 | 11468393 |
| thermal application of bacillus thuringiensis serovar israelensis for dengue vector control. | 2001 | 11469179 | |
| entomopathogenic activities of environmental isolates of bacillus thuringiensis against dipteran larvae. | twenty-five field isolates of bacillus thuringiensis from the lower silesia region of poland, the osola plain, and phylloplane niches and soil samples from the karkonosze national park were tested for insecticidal activity against larvae of the dipterans aedes aegypti, drosophila melanogaster and musca domestica. the spore-crystal mixture of b. thuringiensis finitimus (soil isolate) killed nearly half of the fourth instar larvae of ae. aegypti. similar mortality of between 39-61% was recorded af ... | 2001 | 11469180 |
| population-scale laboratory studies of the effect of transgenic plants on nontarget insects. | studies of the effects of insect-resistant transgenic plants on beneficial insects have, to date, concentrated mainly on either small-scale "worst case scenario" laboratory experiments or on field trials. we present a laboratory method using large population cages that represent an intermediate experimental scale, allowing the study of ecological and behavioural interactions between transgenic plants, pests and their natural enemies under more controlled conditions than is possible in the field. ... | 2001 | 11472551 |
| a phylogenetic analysis of bacillus thuringiensis serovars by rflp-based ribotyping. | to determine the 23s and 5s rrna gene fingerprints in order to reveal phylogenetic relationships among bacillus thuringiensis strains. | 2001 | 11473592 |
| application of bacillus thuringiensis in poultry houses as a biological control agent against the housefly, musca domestica sorbens. | the efficiency of bacillus thuringiensis (b.t) as a microbial housefly control agent was evaluated in one of the natural maggot breeding medium, namely poultry faeces. two commercial formulations, a wettable powder and a liquid concentrate were assayed against musca domestica sorbens in synthetic fly breeding madia and in chicken faeces. the latter was found to favour maggot breeding when compared with the synthetic one. both formulations resulted in significant reduction in maggot numbers,, pup ... | 2001 | 11478452 |
| [investigation of different dosages of inserted bt genes and their insect-resistance in transgenic bt cotton]. | the plants with various dosages of inserted bt genes were developed by intercrossing among transgenic bt lines in which bt genes were inserted in different chromosomes, and commercial non-transgenic bt varieties. laboratory bioassay of insect-resistance and bt toxin protein assays with elisa were used to detect efficacy to bollworm in different cotton growing stages. as transgenic bt insect-resistant cotton, temporal difference of resistance existed in plants converging on different dosages of i ... | 2001 | 11480180 |
| screening of bacillus thuringiensis serotypes by polymerase chain reaction (pcr) for insecticidal crystal genes toxic against coffee berry borer. | using pcr,257 isolates of bacillus thuringiensis(bt) were screened for cry-type genes. of 257 isolates/strains, 60 isolates were identified as cry7/8, 10 isolates as cry3 and 36 isolates as cry 1i. one specific strain of b. thuringiensis (sumiyoshiensis; t03b 001) was investigated for the presence of cry7 and cry8 genes. genes cry7 and cry8 were first detected in this strain using family primers prior to analysis by exclusion polymerase chain reaction (e-pcr) using specific type primers. e-pcr c ... | 2001 | 11480211 |
| a droplet medium selection for cultivation of bacillus thuringiensis. | for an industrial fermentation system, design of a suitable medium for cultivation of cells is an important step. medium selection is commonly carried out with a lot of experimental works. in the present study, a simple method was proposed for medium selection in cultivation of bacillus thuringiensis for production of thuringiensin. a droplet of medium was employed to test the suitability of the medium. | 2001 | 11485443 |
| entomology. first light on genetic roots of bt resistance. | 2001 | 11486062 | |
| identification of a gene associated with bt resistance in heliothis virescens. | transgenic crops producing insecticidal toxins from bacillus thuringiensis (bt) are widely used for pest control. bt-resistant insect strains have been studied, but the molecular basis of resistance has remained elusive. here, we show that disruption of a cadherin-superfamily gene by retrotransposon-mediated insertion was linked to high levels of resistance to the bt toxin cry1ac in the cotton pest heliothis virescens. monitoring the early phases of bt resistance evolution in the field has been ... | 2001 | 11486086 |
| bt toxin resistance from loss of a putative carbohydrate-modifying enzyme. | the development of resistance is the main threat to the long-term use of toxins from bacillus thuringiensis (bt) in transgenic plants. here we report the cloning of a bt toxin resistance gene, caenorhabditis elegans bre-5, which encodes a putative beta-1,3-galactosyltransferase. lack of bre-5 in the intestine led to resistance to the bt toxin cry5b. wild-type but not bre-5 mutant animals were found to uptake toxin into their gut cells, consistent with bre-5 mutants lacking toxin-binding sites on ... | 2001 | 11486087 |
| structural implications for the transformation of the bacillus thuringiensis delta-endotoxins from water-soluble to membrane-inserted forms. | crystal structures combined with biochemical data show that the delta-endotoxins from bacillus thuringiensis are structurally poised towards large-scale, irreversible conformational changes that transform them from the soluble protein bound at the cell surface into a membrane-embedded form causing lysis of susceptible insect cells. cry delta-endotoxins are made of a helix bundle, a beta-prism and a beta-sandwich. the conformational change involves an umbrella-like opening between the helix-4,5-h ... | 2001 | 11498030 |
| construction and characterization of a recombinant bacillus thuringiensis subsp. israelensis strain that produces cry11b. | the mosquitocidal bacterium bacillus thuringiensis subsp. israelensis (bti) produces four major endotoxin proteins, cry4a, cry4b, cry11a, and cyt1a, and has toxicity in the range of many synthetic chemical insecticides. cry11b, which occurs naturally in b. thuringiensis subsp. jegathesan, is a close relative of cry11a, but is approximately 10-fold as toxic to culex quinquefasciatus. to determine whether the addition of cry11b to bti would improve its toxicity, we produced this protein in bti. hi ... | 2001 | 11500092 |
| gene knockout demonstrates that vip3a contributes to the pathogenesis of bacillus thuringiensis toward agrotis ipsilon and spodoptera exigua. | vip3a is an 89-kda protein secreted by bacillus thuringiensis during vegetative growth. to determine the importance of vip3a for the insect pathogenicity of b. thuringiensis the vip3a gene was deleted from strain hd1, yielding strain hd1deltavip3a. compared with hd1, strain hd1deltavip3a was one-fourth as toxic to agrotis ipsilon larvae and less than one-tenth as toxic to spodoptera exigua larvae. when streptomycin was included in the s. exigua diet the toxicity of hd1deltavip3a was approximatel ... | 2001 | 11500093 |
| regeneration of cultured midgut cells after exposure to sublethal doses of toxin from two strains of bacillus thuringiensis. | toxin from two strains of bacillus thuringiensis (bt), aa 1-9 and hd-73, caused dose-dependent destruction of cultured midgut cells from heliothis virescens larvae. hd-73 toxin was more effective although, at the doses used, not all cells were killed. after 2 days of exposure to 0.8 pg/µl aa 1-9 or 0.06 pg/µl hd-73, columnar and goblet cell numbers declined to ca 20% of controls. in contrast, stem and differentiating cells increased to 140-200% of controls. the dynamic of depletion and replaceme ... | 2001 | 11249948 |
| rapid identification of bacillus cereus based on the detection of a 28.5-kilodalton cell surface antigen. | conventional procedures for the identification of suspect bacillus cereus isolated on mannitol-egg yolk-polymyxin (myp) agar may need several days. to facilitate the identification of the bacterium, an enzyme-linked immunosorbent assay (elisa) was developed. the assay was based on the detection of a 28.5-kda cell surface antigen of b. cereus. bacterial colonies grown on myp agar or nutrient agar were suspended in phosphate-buffered saline (ph 7.2) containing 0.1% teepol. the cell suspensions wer ... | 2001 | 11252478 |
| structural and functional studies of alpha-helix 5 region from bacillus thuringiensis cry1ab delta-endotoxin. | the crystal insecticidal proteins from bacillus thuringiensis are modular proteins comprised of three domains connected by single linkers. domain i is a seven alpha-helix bundle, which has been involved in membrane insertion and pore formation activity. site-directed mutagenesis has contributed to identify regions that might play an important role in the structure of the pore-forming domain within the membrane. there are several evidences that support that the hairpin alpha4-alpha5 inserts into ... | 2001 | 11257515 |
| kinetic resolution of chiral amines with omega-transaminase using an enzyme-membrane reactor. | a kinetic resolution process for the production of chiral amines was developed using an enzyme-membrane reactor (emr) and a hollow-fiber membrane contactor with (s)-specific omega-transaminases (omega-ta) from vibrio fluvialis js17 and bacillus thuringiensis js64. the substrate solution containing racemic amine and pyruvate was recirculated through the emr and inhibitory ketone product was selectively extracted by the membrane contactor until enantiomeric excess of (r)-amine exceeded 95%. using ... | 2001 | 11257600 |
| elevating the terms of the gm food debate. | 2001 | 11259173 | |
| [natural insecticides]. | 2001 | 11268634 | |
| reaping a biotech blunder. | 2001 | 11272263 | |
| risk assessment of etofenprox (vectron) on non-target aquatic fauna compared with other pesticides used as simulium larvicide in a tropical environment. | within the rotational scheme developed by the programme to fight the resistance of simulium damnosum to chemical larvicides, there was an operational gap at discharges between 5 and 70 m3 s(-1) for the treatment of rivers where resistance to organophosphates was present. the use of permethrin and carbosulfan was precluded because of risk of environmental impact and, bacillus thuringiensis ser. h-14 treatments were not envisageable due to cost and logistics constraints. among the possible complem ... | 2001 | 11272920 |
| the pathogenicity of bacillus thuringiensis ssp. kurstaki to gamma-irradiated cadra cautella (walker) (lepidoptera: phycitidae). | the present investigation deals with the effects of bacillus thuringiensis ssp. kurstaki on various biological parameters of gamma-irradiated cadra cautella. the pathogen, irradiation, and their combinations significantly affected the insects by increasing their mortality and developmental periods, reducing the pupal and adult survival (%), and the adult longevity and reproductive potential were also significantly reduced. it was observed that irradiation-pathogen combinations produced additive ... | 2001 | 11273688 |
| how bacillus thuringiensis has evolved specific toxins to colonize the insect world. | bacillus thuringiensis is a bacterium of great agronomic and scientific interest. together the subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. this is mainly determined by the arsenal of crystal proteins that the bacterium produces during sporulation. here we describe the properties of these toxin proteins and the current knowledge of the basis for their specificity. assessment of phylog ... | 2001 | 11275324 |
| lack of cross-resistance to cry19a from bacillus thuringiensis subsp. jegathesan in culex quinquefasciatus (diptera: culicidae) resistant to cry toxins from bacillus thuringiensis subsp. israelensis. | culex quinquefasciatus mosquitoes with high levels of resistance to single or multiple toxins from bacillus thuringiensis subsp. israelensis were tested for cross-resistance to the bacillus thuringiensis subsp. jegathesan polypeptide cry19a. no cross-resistance was detected in mosquitoes that had been selected with the cry11a, cry4a and cry4b, or cry4a, cry4b, cry11a, and cyta toxins. a low but statistically significant level of cross-resistance, three to fourfold, was detected in the colony sel ... | 2001 | 11282656 |
| survey raises concerns about bt resistance management. | 2001 | 11283558 | |
| expression of mosquito active toxin genes by a colombian native strain of the gram-negative bacterium asticcacaulis excentricus. | mosquito control with biological insecticides, such as bacillus sp. toxins, has been used widely in many countries. however, rapid sedimentation away from the mosquito larvae feeding zone causes a low residual effect. in order to overcome this problem, it has been proposed to clone the bacillus toxin genes in aquatic bacteria which are able to live in the upper part of the water column. two strains of asticcacaulis excentricus were chosen to introduce the b. sphaericus binary toxin gene and b. t ... | 2001 | 11285507 |
| the tc genes of photorhabdus: a growing family. | the toxin complex (tc) genes of photorhabdus encode insecticidal, high molecular weight tc toxins. these toxins have been suggested as useful alternatives to those derived from bacillus thuringiensis for expression in insect-resistant transgenic plants. although photorhabdus luminescens is symbiotic with nematodes that kill insects, tc genes have recently been described from other insect-associated bacteria such as serratia entomophila, an insect pathogen, and yersinia pestis, the causative agen ... | 2001 | 11286884 |
| antibacterial efficacy of triclosan-incorporated polymers. | triclosan (2, 4, 4'-trichloro-2'-hydroxydiphenyl ether) is a broad-spectrum antimicrobial agent, routinely used in various personal care products.(1) it is also incorporated into polymers through melt-mixing, with the aim of providing persistent antibacterial action on the surface of the polymer.(2,3) such triclosan-incorporated polymers can be promoted for hospital use as fabric seat covers, tables, chairs, and clothing. we assessed the antibacterial efficacy of triclosan-incorporated polymer d ... | 2001 | 11287882 |
| a battery-powered notebook thermal cycler for rapid multiplex real-time pcr analysis. | a compact, real-time pcr instrument was developed for rapid, multiplex analysis of nucleic acids in an inexpensive, portable format. the instrument consists of a notebook computer, two reaction modules with integrated optics for four-color fluorescence detection, batteries, and a battery-charging system. the instrument weighs 3.3 kg, measures 26 x 22 x 7.5 cm, and can run continuously on the internal batteries for 4 h. independent control of the modules allows differing temperature profiles and ... | 2001 | 11199979 |
| screening of the bacillus thuringiensis cry1ac delta-endotoxin on the artificial phospholipid monolayer incorporated with brush border membrane vesicles of plutella xylostella by optical biosensor technology. | the binding of cry1ac, an insecticidal protein of bacillus thuringiensis, to a brush border membrane (bbm) isolated from midguts of the diamondback moth plutella xylostella was examined by surface plasmon resonance (spr)-based biosensor. bbm was mixed with 1,3-ditetradecylglycero-2-phosphocholine (pc14), a neutral charged artificial lipid, and was reconstructed to a monolayer on a hydrophobic chip for the biosensor. the binding of cry1ac to the reconstructed monolayer was analyzed by a two-state ... | 2001 | 11245889 |
| [cloning of parasporal body protein gene resembling to s-layer protein genes from bacillus thuringiensis ctc strain]. | bacillus ctc strain was identified as bacillus thuringiensis subsp. finitimus (serotype h2) and pasteur institute confirmed this identification. the parasporal body formed by ctc strain is oval shaped, and consists of 100 kd protein. the determination of the n-terminal amino acid sequence showed this protein shares 93% similarity to that of b. anthracis s-layer proteins. the restriction map covering the related protein gene (ctc) was deduced according to southern hybridization. the dna fragments ... | 2001 | 12549017 |
| [detection of enterotoxin genes in bacillus thuringiensis by pcr]. | the presence of hemolysin hbla (hbla), enterotoxin bcet (bcet) and enterotoxin s (ents) genes from 45 strains of b. thuringiensis, 4 strains of b. cereus and b. sphaericus have been detected respectively by multiple pcr. the results showed that 95.6% b. thuringiensis strains contain the b component of hbla gene, 91.1% and 93.3% of them contain bcet and ents genes sequences respectively. the enterotoxin productions in all strains have also been analysis using two commercial immunoassay kits(tecra ... | 2001 | 12549018 |
| [expression of two truncated enhancin gene from helicoverpa armigera granulosis virus in e. coli and its preliminary bioassay]. | the plasmids pet-30a-ben and pet-30a-den which included 1.7 kd and 2.2 kb fragments of 5'-terminal of hagv enhancin gene were obtained by cutting recombinant plasmid pet-30a-en with bal i and dra i respectively. two fragments were expressed in e. coli successfully and the products were named ben and den respectively. the enhancement, which ben and den enhance the infectivity of hanpv and bt in 3rd larvae of helicoverpa armigera, was studied. the results indicated that there was increase of the m ... | 2001 | 12549021 |
| [identification and location of the toxin protein genes in 56 bacillus thuringiensis isolates]. | polymerase chain reaction was performed to screen bacillus thuringiensis isolates for cryi, cryiii, and cryv genes with cryi-, cryiii-, and cryv-specific primers respectively. the results indicated that, in the 56 bt isolates examined, 7 isolates contain cryi gene, 2 isolates contain cryiii gene, and 21 isolates contain both cryi and cryv genes. the cryv gene was located by southern hybridization in the large plasmid of about 150 md molecular mass. | 2001 | 12549082 |
| [transcriptional activator plcr regulate the expression of multiple genes in bacillus cereus]. | food-poisoning and some diseases of human can be caused by potential pathogenic factors including phospholipases of c-type, hemolysins, enterotoxins, emetic toxin and others from bacillus cereus which is an opportunistic pathegon. generally, the expression of pathogenic genes is completed by a co-regulation in many bacteria. the isolation of a mutant, displaying significant reducing expression of lecithinase and general proteolytic activities, from a transposon-induced bank of b. cereus type str ... | 2001 | 12549084 |
| [some biological characteristics of genetically engineered insecticidal pseudomonas fluorescens]. | plasmid stability, antifungal activity, plant-colonizing ability, uv resistance and inseticidal activity in field were analysed for the engineered pseudomonas fluorescens (pf) strain ipp202. the results indicated that the recombinant plasmid in ipp202 was very stable after successive diluting culturing and after continuous culturing, there was no significant change in the properties beneficial to plants, such as antifungal activity and plant-colonizing ability as compared with the original strai ... | 2001 | 12549181 |
| wastewater treatment sludge as a raw material for the production of bacillus thuringiensis based biopesticides. | seven wastewater sludges of different origins and types were used as an alternate culture medium for producing bacillus thuringiensis variety kurstaki hd-1. the sludge samples were used under three different preparations: without pre-treatment, with acid treatment (hydrolysed sludge) and the supernatant obtained after centrifugation of the hydrolysed sludge. the sludge composition varied widely with origin and the type of sludge. growth and sporulation were evaluated by the total viable cell cou ... | 2001 | 12230163 |
| pest insect control in organically-produced crops of field vegetables. | in the uk, the demand for organic vegetable and salad crops is increasing, mainly as a result of the requirements of the multiple retailers. however, approximately 85% of the organic fruit and vegetable produce sold in the uk is imported. a major constraint to growing field vegetable crops, and particularly organically-produced crops, is the reduction in crop yield and quality caused by pest insects. this paper will consider the control techniques currently available to organic growers and other ... | 2001 | 12425046 |
| first steps to improve cotton crop management in thailand. | thai cotton growers yearly face serious pest problems consisting of heavy infestation associated with resistance to pesticides leading to expensive and harmful pest control practices. thanks to a multi discipline research work carried out from 1991 to 1996, a decision-oriented model for cotton crop management was developed and compared to farmers' practices during the 1988 cotton growing season 1998 in klang hat district, thailand. this model, based on plant monitoring, involved a new cotton cul ... | 2001 | 12425063 |
| comparison of different methodologies for binding assays of bacillus thuringiensis toxins to membrane vesicles from insect midguts. | 2001 | 12009811 | |
| pcr-aided synthesis and stable expression in e.coli of the cryia (c)bt gene. | insecticidal crystal proteins, known as delta-endotoxins, from a gram-positive bacterium bacillus thuringiensis have been used as bio-pesticides for over 3 decades. by using a successive pcr method, the 1.8 kb cryia (c)bt gene coding for the fragment of protoxin was synthesized. different from b. thuringiensis subsp. kurstaki hd 73 cry gene, the synthesized gene has the codon usage pattern of an average pseudomonas spp gene. 614 nucleotides were changed in the synthesized cryia (c)bt gene and th ... | 2001 | 12050814 |
| comparative toxicity of selected larvicidal formulations against anopheles stephensi liston and aedes aegypti linn. | toxicity of selected larvicidal formulations of bacillus sphaericus, bacillus thuringiensis h-14 israelensis (bti) and insect growth regulators was determined against anopheles stephensi and aedes aegypti, the two major urban mosquito vectors of malaria and dengue fever in india respectively. the study revealed that the formulations of bacillus thuringiensis h-14 and igr compounds were highly toxic against both the mosquito species but bacillus sphaericus formulation was less toxic against aedes ... | 2001 | 12170930 |