Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| gil16, a new gram-positive tectiviral phage related to the bacillus thuringiensis gil01 and the bacillus cereus pbclin15 elements. | one of the most notable characteristics of tectiviridae resides in their double-layer coats: the double-stranded dna is located within a flexible lipoprotein vesicle covered by a rigid protein capsid. despite their apparent rarity, tectiviruses have an extremely wide distribution compared to other phage groups. members of this family have been found to infect gram-negative (prd1 and relatives) as well as gram-positive (bam35, gil01, ap50, and phins11) hosts. several reports have shown that tecti ... | 2005 | 15743944 |
| fingerprinting of bacillus thuringiensis type strains and isolates by using bacillus cereus group-specific repetitive extragenic palindromic sequence-based pcr analysis. | a total of 119 bacillus thuringiensis strains (83 type strains and 26 native isolates), as well as five b. cereus group species, were analyzed by repetitive extragenic palindromic sequence-based pcr analysis (rep-pcr) fingerprinting. primers bc-rep-1 and bc-rep-2 were specifically designed according to an extragenic 26-bp repeated sequence found in the six b. cereus group genomes reported. a total of 47 polymorphic bands were detected, and the patterns varied from 5 to 13 bands in number and fro ... | 2005 | 15746337 |
| quantitative molecular assay for fingerprinting microbial communities of wastewater and estrogen-degrading consortia. | a quantitative fingerprinting method, called the real-time terminal restriction fragment length polymorphism (real-time-t-rflp) assay, was developed for simultaneous determination of microbial diversity and abundance within a complex community. the real-time-t-rflp assay was developed by incorporating the quantitative feature of real-time pcr and the fingerprinting feature of t-rflp analysis. the assay was validated by using a model microbial community containing three pure strains, an escherich ... | 2005 | 15746346 |
| improvement of bioinsecticides production through adaptation of bacillus thuringiensis cells to heat treatment and nacl addition. | the present work aimed to increase yields of delta-endotoxin production through adaptation of bacillus thuringiensis cells to heat shock and sodium chloride and to investigate their involvements in bioinsecticides production improvement. | 2005 | 15752327 |
| purification, amino acid sequence and characterization of bacthuricin f4, a new bacteriocin produced by bacillus thuringiensis. | purification and characterization of a new bacteriocin, bacthuricin f4 of bacillus thuringiensis. | 2005 | 15752334 |
| characterization of melanin produced by a wild-type strain of bacillus thuringiensis. | bt l-7601 is a uv resistant wild-type strain, which belongs to bacillus thuringiensis subsp. dendrolimus serotype h4a4b. it was isolated from nature, and produced a dark brown pigment during the exponential phase of growth. bt l-7601 had the ability to produce pigment in a general nutrition-abundant medium, which had no l-tyrosine. the pigment was identified as melanin based on chemical testing, its light absorbance, and ft-ir analysis. bt l-7601 has a strong resistance to uv light. after 30 min ... | 2004 | 15754243 |
| cry1ab protoxin effects on spodoptera frugiperda (lepidoptera: noctuidae) and its parasitoid cotesia marginiventris (hymenoptera: braconidae). | 2004 | 15759410 | |
| transgenic-bt potato plant resistance to the colorado potato beetle affect the aphid parasitoid aphidius nigripes. | using the biotechnological plant resistance for herbivore control with less reliance on chemicals in integrated pest management (ipm) programs critically depends on predictable interactions with no-target organisms of various trophic levels. plant resistance to insect pests based on recombinant bacillus thuringiensis could interfere with natural enemies of non target pests. performance of the potato aphid parasitoid aphidius nigripes was studied on the 'superior-bt line transgenic for the crylli ... | 2004 | 15759411 |
| bioassay of some egyptian isolates of bacillus thuringiensis against culex pipiens (diptera: culicidae). | some egyptian isolates of bacillus thuringiensis (bt) were grown on economic media contain 4% of fodder yeast in tap water and incubated under shaking conditions for four days. the biological activities of these isolates against culex pipiens (diptera: culicidae) were carried out to determine their effectiveness against field and laboratory strains of 3rd larval instar. all isolates of bt were more pathogenic to laboratory strain. causing up to 84% larval mortality. the insecticidal activities o ... | 2004 | 15759417 |
| seasonal occurrence and relative abundance of aphids on potato plants with classical and transgenic characters of resistance to colorado potato beetle leptinotarsa decemlineata (say). | the seasonal abundance and dynamics of potato-infesting aphids were studied in two seasons, on potato solanum tuberosum l. with various types of transgenic and classical resistance to primary pests, especially the colorado potato beetle (cpb), leptinotarsa decemlineata (say). the lines tested were the newleaf potato, a transgenic expressing the bacillus thuringiensis cryiiia toxin (btt); nyl 235-4 a parental line derived from s. berthaultii (nyl) with a high density of glandular trichomes; and a ... | 2004 | 15759424 |
| [structural changes in cry3a delta-endotoxin from bacillus thuringiensis var. tenebrionis in alcohol solutions at ph 2.0]. | conformational changes in cry3a delta-endotoxin caused by three different alcohols (ethanol, butanol, and isopropanol) were studied using the methods of circular dichroism, scanning microcalorimetry, and electron miscroscopy. it was shown that, in addition to the standard decrease in the native structure stability, the alcohols can cause a conformational transition that results in a sharp increase in the beta-structure content and a change in the environment of aromatic residues. the conformatio ... | 2005 | 15759500 |
| isolation, purification and physicochemical characterization of water-soluble bacillus thuringiensis melanin. | melanins are widely used in medicine, pharmacology, cosmetics and other fields. although several technologies for the purification of water-insoluble dioxyphenylalanine (dopa) melanins have been described, a source of water-soluble melanin is highly desirable. here we describe an effective procedure for the isolation and purification of water-soluble melanin using the culture medium of bacillus thuringiensis subsp. galleriae strain k1. water-soluble melanin from this organism has an isoelectric ... | 2005 | 15760342 |
| selective feeding of tobacco budworm and bollworm (lepidoptera: noctuidae) on meridic diet with different concentrations of bacillus thuringiensis proteins. | laboratory experiments were conducted to evaluate the behavior of bollworm, helicoverpa zea (boddie), and tobacco budworm, heliothis virescens (f.), larvae on meridic diet with different concentrations of the cry1ac and cry2ab proteins from bacillus thuringiensis subsp. kurstaki berliner. the proteins used in these experiments are the ones in commercially available bollgard and bollgard ii cotton. both bollworms and tobacco budworms selectively fed on nontreated diet compared with diet treated w ... | 2005 | 15765669 |
| verification of a european corn borer (lepidoptera: crambidae) loss equation in the major corn production region of the northeastern united states. | field studies in pennsylvania and maryland were conducted during 2000, 2001, and 2002 to test the applicability of published yield loss relationships developed in central pennsylvania for european corn borer, ostrinia nubilalis (hübner), management in warmer, longer season corn, zea mays l., grain production regions of the northeastern united states. both isoline hybrids and non-bt lead hybrids were compared against bacillus thuringiensis (bt) hybrids to measure effects of the pest on yield. the ... | 2005 | 15765671 |
| spatial prediction of corn rootworm (coleoptera: chrysomelidae) adult emergence in iowa cornfields. | the most common management options for corn rootworms are rotating corn with nonhost crops, planting genetically engineered corn resistant to corn rootworms (e.g., bacillus thuringiensis [bt] corn), and treating with a soil insecticide at planting time. because these control tactics are preventive, the decision to apply controls has been made without any knowledge of rootworm density and spatial distribution. this study was conducted to predict the spatial distribution of adult emergence and to ... | 2005 | 15765673 |
| seasonal expression profiles of insecticidal protein and control efficacy against helicoverpa armigera for bt cotton in the yangtze river valley of china. | seasonal levels of bacillus thuringiensis (bt) insecticidal protein and its control efficacy against helicoverpa armigera (hübner) in bt transgenic cotton gk19 (carrying a cry1ac/cry1ab fused gene) and bg1560 (carrying a cry1ac gene) were investigated in tianmen county, hubei province, located in the yangtze river valley of china, in 2001 and 2002. the results showed that the toxin content in bt cotton changed significantly over time, and that the structure, growth stage, and variety were signif ... | 2005 | 15765683 |
| reducing mutational bias in random protein libraries. | the success of protein optimization through directed molecular evolution depends to a large extent on the size and quality of the displayed library. current low-fidelity dna polymerases that are commonly used during random mutagenesis and recombination in vitro display strong mutational preferences, favoring the substitution of certain nucleotides over others. the result is a biased and reduced functional diversity in the library under selection. in an effort to reduce mutational bias, we combin ... | 2005 | 15766704 |
| characterization of a novel vip3-type gene from bacillus thuringiensis and evidence of its presence on a large plasmid. | a novel vip3-type gene named vip3lb has been isolated from bacillus thuringiensis strain bupm95. the corresponding secreted vegetative insecticidal protein was active against the lepidopteran insect ephestia kuehniella. the vip3lb gene was shown, for the first time, to be carried by the large plasmid containing the cry1ia genes of b. thuringiensis. the nucleotide sequence predicted a protein of 789 amino acids residues with a calculated molecular mass of 88.5kda. both nucleotide and amino acid s ... | 2005 | 15766790 |
| evolution of resistance toward bacillus sphaericus or a mixture of b. sphaericus+cyt1a from bacillus thuringiensis, in the mosquito, culex quinquefasciatus (diptera: culicidae). | the 2362 strain of bacillus sphaericus (bs) neide is a highly mosquitocidal bacterium used in commercial bacterial larvicides primarily to control mosquitoes of the genus culex. unfortunately, bs is at high risk for selecting resistance in mosquito populations, because its binary toxin apparently only binds to a single receptor type on midgut microvilli. a potential key strategy for delaying resistance to insecticidal proteins is to use mixtures of toxins that act at different targets within the ... | 2005 | 15766932 |
| cost-effective production of bacillus thuringiensis by solid-state fermentation. | production of bacillus thuringiensis (bt) was standardized on wheat bran based media in 250 ml erlenmeyer flasks. scale-up of bt production on the best medium in plastic tubs with aeration at 8 h intervals starting 16 h after incubation yielded a significant increase in spore count and toxin content of the product. maximum lysis of bt cells was obtained by 60 h of incubation at 30 degrees c. this protocol was suitable for production of bt strains and local isolates. the bt produced proved highly ... | 2005 | 15766933 |
| bacillus thuringiensis delta-endotoxin cry1ac domain iii enhances activity against heliothis virescens in some, but not all cry1-cry1ac hybrids. | we investigated the role of domain iii of bacillus thuringiensis delta-endotoxin cry1ac in determining toxicity against heliothis virescens. hybrid toxins, containing domain iii of cry1ac with domains i and ii of cry1ba, cry1ca, cry1da, cry1ea, and cry1fb, respectively, were created. in this way cry1ca, cry1fb, and to a lesser extent cry1ba were made considerably more toxic. | 2005 | 15766934 |
| [changes in superoxide dismutase activity in various larval organs of greater wax moth (galleria mellonella l., lepidoptera: pyralidae) induced by infection with bacillus thuringiensis ssp. galleriae]. | we studied the changes in superoxide dismutase activity in organs of galleria mellonella larvae infected with two strains of bacillus thuringiensis. a considerable increase in superoxide dismutase activity was observed at the initial stages of infection, later the enzyme activity decreased and this decrease was timed to cessation of feeding and development of sepsis in the infected larvae. changes in the enzyme activity in the organs of larvae infected with a highly virulent strain of b. thuring ... | 2005 | 15768635 |
| bacillus cereus food poisoning and its toxins. | the genus bacillus includes members that demonstrate a wide range of diversity from physiology and ecological niche to dna sequence and gene regulation. the species of most interest tend to be known for their pathogenicity and are closely linked genetically. bacillus anthracis causes anthrax, and bacillus thuringiensis is widely used for its insecticidal properties but has also been associated with foodborne disease. bacillus cereus causes two types of food poisoning, the emetic and diarrheal sy ... | 2005 | 15771198 |
| characterization of cultured insect cells selected by bacillus thuringiensis crystal toxin. | selection for resistance against bacillus thuringiensis (bt) cry1ac10 in the trichoplusia ni (hubner) cell line bti-tn-5b1-4 (tnh5) was tested, and the development of resistance in the selected cells was like a s-form curve. monitoring at the cry1ac10 50th challenge, the resistance ratio was 1,294-fold as many as that of initial cells. but the resistance to cry1ac10 declined gradually when the selection was relaxed. the resistance declined rapidly at the low level of resistance and slowly at the ... | 2004 | 15780008 |
| bt176 corn in poultry nutrition: physiological characteristics and fate of recombinant plant dna in chickens. | a genetically modified bt176 corn hybrid, which contains an insecticidal protein against the european corn borer, and its conventional, nonmodified counterpart were evaluated in 4 separate trials to verify substantial equivalence in feeding value and animal performance. thirty-six individually kept laying hens and 3 replicates of 94 broiler chickens each, assigned to 12 cages, were fed 2 different hen and broiler diets containing either 60% conventional or 60% bt176 corn. the nutrient compositio ... | 2005 | 15782906 |
| evaluation of transgenic hybrid corn (vip3a) in broiler chickens. | a 49-d feeding study evaluated whether standard broiler diets prepared with syngenta seeds vip3a transgenic derived corn grain had any unanticipated adverse effects on male or female broiler chickens as compared with diets prepared with nontransgenic (isoline) control corn grain. two commercial lots of grain grown in north carolina during the 1999 (nc 1999) and 2000 (nc 2000) seasons were included for reference purposes. broiler growth was excellent with males reaching 3466 g and females reachin ... | 2005 | 15782922 |
| genetic diversity among bacillus anthracis, bacillus cereus and bacillus thuringiensis strains using repetitive element polymorphism-pcr. | repetitive element polymorphism-pcr (rep-pcr) is one of the tools that has been used to elucidate genetic diversity of related microorganisms. using the mb1 primer, rep-pcr fingerprints from 110 bacillus strains within the "b. cereus group" have identified eighteen distinct categories, while other more distantly related bacterial species fell within six additional categories. all bacillus anthracis strains tested were found to be monomorphic by fluorophore-enhanced rep-pcr (ferp) fingerprinting ... | 2004 | 15790070 |
| structural requirements of the unique disulphide bond and the proline-rich motif within the alpha4-alpha5 loop for larvicidal activity of the bacillus thuringiensis cry4aa delta-endotoxin. | both the disulphide bond (cys192-cys199) and the proline-rich motif (pro193proasnpro196) in the long loop connecting the alpha4-alpha5 transmembrane hairpin of the cry4aa mosquito-larvicidal protein have been found to be unique among the bacillus thuringiensis cry delta-endotoxins. in this study, their structural requirements for larvicidal activity of the cry4aa toxin were investigated. c192a and c199a mutant toxins were initially generated and over-expressed in escherichia coli cells as 130-kd ... | 2005 | 15796913 |
| the photorhabdus pir toxins are similar to a developmentally regulated insect protein but show no juvenile hormone esterase activity. | the genome of the insect pathogen photorhabdus luminescens strain tt01 contains numerous genes predicting toxins and proteases. within the p. luminescens tt01 genome, the products of two loci, plu 4093-plu 4092 and plu 4437-plu 4436, show oral insecticidal activity against both moth and mosquito larvae. the proteins encoded by these loci, here termed 'photorhabdus insect related' (pir) proteins a and b, show similarity both to delta-endotoxins from bacillus thuringiensis (bts) and a developmenta ... | 2005 | 15796978 |
| multilocus sequence typing reveals that bacillus cereus strains isolated from clinical infections have distinct phylogenetic origins. | eight strains of bacillus cereus isolated from bacteremia and soft tissue infections were assigned to seven sequence types (sts) by multilocus sequence typing (mlst). two strains from different locations had identical sts. the concatenated sequences of the seven sts were aligned with 65 concatenated sequences from reference sts and a neighbor-joining tree was constructed. two strains were distantly related to all reference sts. three strains were recovered in a clade that included bacillus anthr ... | 2005 | 15796996 |
| interaction of cytolytic toxin cytb with a supported lipid bilayer: study using an acoustic wave device. | an acoustic technique was used to monitor the interaction of the pore-forming cytolytic toxin cytb with a positively charged supported lipid bilayer. the acoustic device, which is based on a waveguide geometry, is sensitive to changes in the mass of the supported bilayer. the specificity of the interaction, rate and extent of the association, reversibility and effect of previous depositions of toxin were investigated. the cytb was found to bind irreversibly to the lipids at all fractional covera ... | 2004 | 15803723 |
| genomics of the bacillus cereus group of organisms. | members of the bacillus cereus group of organisms include bacillus cereus, bacillus anthracis and bacillus thuringiensis. collectively, these organisms represent microbes of high economic, medical and biodefense importance. given this significance, this group contains the highest number of closely related fully sequenced genomes, giving the unique opportunity for thorough comparative genomic analyses. much of the disease and host specificity of members of this group can be attributed to their pl ... | 2005 | 15808746 |
| [comparative study of the expression of the native and modified cry3a genes of bacillus thuringiensis in prokaryotic and eukaryotic cells]. | the cry3a gene of bacillus thuriengiensis was cloned. based on sequence analysis of this gene, a modified gene, cry3am, was constructed, which has the optimal codon composition for effective expression in eukaryotic cells. hybrid genes cry3a-licbm2 and cry3am-licbm2 were constructed, in which the sequences of the native and modified genes are fusedfused with the reorter gene for thermostable lichenase in the reading frame. we have shown that the expression levels of hybrid genes cry3a-licbm2 and ... | 2005 | 15810606 |
| [antioxidants activity in intestines of larvae galleria mellonella l. (lepidoptera, pyralidae) during bacillus thuringiensis ssp galleriae infection]. | 2005 | 15810658 | |
| crystal structure of the mosquito-larvicidal toxin cry4ba and its biological implications. | cry4ba, isolated from bacillus thuringiensis subsp. israelensis, is specifically toxic to the larvae of aedes and anopheles mosquitoes. the structure of activated cry4ba toxin has been determined by multiple isomorphous replacement with anomalous scattering and refined to r(cryst) = 20.5% and r(free)= 21.8% at 1.75 angstroms resolution. it resembles previously reported cry toxin structures but shows the following distinctions. in domain i the helix bundle contains only the long and amphipathic h ... | 2005 | 15811374 |
| characterization of cry34/cry35 binary insecticidal proteins from diverse bacillus thuringiensis strain collections. | bacillus thuringiensis crystal proteins of the cry34 and cry35 classes function as binary toxins showing activity on the western corn rootworm, diabrotica virgifera virgifera leconte. we surveyed 6,499 b. thuringiensis isolates by hybridization for sequences related to cry35a genes, identifying 78 strains. proteins of the appropriate molecular mass (ca. 44 kda) for cry35 were observed in 42 of the strains. full-length, or nearly full-length, sequences of 34 cry34 genes and 16 cry35 genes were al ... | 2005 | 15811999 |
| flocculation of bacillus thuringiensis var. israelensis suspension and its efficacy against mosquito larvae. | bacillus thuringiensis ssp. israelensis (bti) is increasingly used as an ecologically friendly anti-mosquito agent. the bacterium cells undergo fermentation in dilute suspensions; before practical use, therefore it is necessary to concentrate the suspensions. aggregation by polymers is a powerful tool with which to regulate the stability of suspensions. typically, polymers at low concentrations destabilize and at high concentrations stabilize colloidal systems. bti suspensions can be flocculated ... | 2005 | 15813223 |
| refuges in india and delayed resistance to bt crops. | 2005 | 15815660 | |
| eicosanoids mediate the laminarin-induced nodulation response in larvae of the flesh fly, neobellieria bullata. | insects have a highly developed innate immune system, including humoral and cellular components. the cellular immune responses refer to hemocyte-mediated processes such as phagocytosis, nodulation, and encapsulation. nodulation is considered the predominant defense reaction to infection in insects. treating third instar larvae of the grey flesh fly, neobellieria bullata, with laminarin (beta-1,3-glucan, a typical component of fungal cell walls) induced nodulation in a dose-dependent manner. this ... | 2005 | 15822095 |
| [effects of bacillus thuringiensis transgenic rice and chemical insecticides on arthropod communities in paddy-fields]. | this paper assessed the effects of cry1abl/cry1ac-carrying transgenic bacillus thuringiensis rice (bt rice) and chemical insecticides on the arthropod communities under paddy-field conditions in terms of arthropod guild dominance, family composition and dominance distribution of each guild, individuals of each guild, some common indices of arthropod communities, and community dissimilarity. in most cases, no significant differences were found between the bt and control rice plots without any che ... | 2004 | 15825447 |
| impact of environmental factors on the toxicity of bacillus thuringiensis var. israelensis ips82 to chironomus kiiensis. | to determine the feasibility of microbiological control of chironomid larvae in water sources for the city of shenzhen, china, the toxicity characteristics of bacillus thuringiensis var. israelensis (bti) ips82 on chironomus kiiensis tokunaga were studied. tests on fermentation products of ips82 showed good correlations between toxicity, cell density, dissolved oxygen, and the spore-forming phase. in this study, bioassays were carried out with different stage larvae. results showed that the lc50 ... | 2005 | 15825763 |
| integration of bacillus thuringiensis h-14 formulations and pyriproxyfen for the control of larvae of aedes aegypti and aedes albopictus. | studies were carried out on the bioefficacy and residual activity of bacillus thuringiensis israelensis h-14 (bti) (water-dispersible granules of vectobac abg 6511 and liquid formulations of vectobac 12as) and pyriproxyfen (insect growth regulator, sumilarv 0.5%) as direct applications for control of larvae of aedes aegypti and aedes albopictus. two dosages of each bti formulation (285 and 570 international toxic units [itu]/liter) and the integration of both bti formulations and pyriproxyfen we ... | 2005 | 15825767 |
| redirection of metabolism during nutrient feeding in fed-batch cultures of bacillus thuringiensis. | during sporulation, bacillus thuringiensis produces insecticidal crystal inclusions (cry proteins) encoded by cry genes. in fed-batch cultures (fbcs), spores and cry protein yields are usually low, so we therefore studied the pattern of metabolic changes occurring in batch cultures and fbcs of a b. thuringiensis strain having a cry1aa promoter-lacz fusion, and their effect on sporulation and cry1a gene expression. in fbcs, there was a redirection of bacterial metabolism and a reduction in the sp ... | 2004 | 15834720 |
| [the chemotactic characteristics of the s and r dissociants of bacillus thuringiensis]. | the chemotactic responses of bacillus thuringiensis subsp. dendrolimus (strain 49) and thuringiensis (strain 2002) and their morphological dissociants were studied by using some natural and artificial substances as effectors. the 12-h-old wild-type cells (s variants) of both strains were found to be motile and similar in their chemotactic responses, whereas the chemotactic responses of r variants were different. | 2005 | 15835783 |
| transfer and expression of the mosquitocidal plasmid pbtoxis in bacillus cereus group strains. | the toxicity of bacillus thuringiensis subsp. israelensis to dipteran larvae (mosquitoes and black flies) depends on the presence of the pbtoxis plasmid. in this paper, two antibiotic resistance tagged pbtoxis were transferred by conjugation to other bacillus cereus group strains. among 15 potential recipients, only a lepidopteran active b. thuringiensis subspecies kurstaki and a b. cereus strain received the plasmid pbtoxis with a low transfer rate of about 10(-8) transconjugants/recipient. the ... | 2005 | 15837378 |
| plasmid-encoded regulator of extracellular proteases in bacillus anthracis. | bacillus anthracis sterne cured of the pxo1 plasmid had enhanced secreted protease activity during the postexponential phase but no change in hemolytic or lecithinase activities. a zymogen profile revealed at least six proteases, including serine, metal, and perhaps cysteine types. there were similar amounts of protease secreted by the closely related species bacillus cereus and bacillus thuringiensis, but the patterns differed. among the pxo1 plasmid-encoded proteins, there is a tetratricopepti ... | 2005 | 15838040 |
| comparison of broiler performance when fed diets containing corn grain with insect-protected (corn rootworm and european corn borer) and herbicide-tolerant (glyphosate) traits, control corn, or commercial reference corn. | a 42-d feeding experiment with growing ross x ross 508 broilers showed that the nutritional value of insect-protected and herbicide-tolerant corn was comparable to that of the genetically similar control and 5 commercial reference corn hybrids. mon 88017 provides protection from feeding damage by coleopteran pest corn rootworm and is tolerant to the action of glyphosate, the active ingredient in the roundup family of agricultural herbicides. mon 88017 x mon 810 was developed by the traditional b ... | 2005 | 15844815 |
| [use of the restriction analysis in the quality control of the strain of cuban biolarvicide bactivec]. | the genomic characterization of the strain used in manufacturing biolarvicide bactivet was shown in this paper. digestion patterns of bacillus thuringiensis reference strain 266 from the collection of pushkin institute located in former leningrad and of two strains isolated from 2 batches of biolarvicide were compared. chromosomal dna digestion was performed by enzymes hindlll and ecori. the same restriction pattern was observed in all cases, which is indicative of genetic stability of the activ ... | 2004 | 15846913 |
| [construction of bacillus thuringiensis labeled recombinant strain and horizontal transfer of its cry1ac10 gene]. | a recombinant plasmid pbmbzgc10 was obtained by the ligation of gfp-cry1ac10 fusion gene and vector plasmid pad4412, which was then introduced by gene pulser into acrystalliferous strain cryb, and a recombinant strain cryb(pbmbzgc10) was obtained. different fermentative solutions of recombinant strain were used for multi-spraying on brassica pekinesis, ipomoea aquatica and lycopersicon esculentum leaves. the results of fluorescent detection and pcr amplification revealed that cry1ac10 gene did n ... | 2005 | 15852975 |
| insect-resistant gm rice in farmers' fields: assessing productivity and health effects in china. | although no country to date has released a major genetically modified (gm) food grain crop, china is on the threshold of commercializing gm rice. this paper studies two of the four gm varieties that are now in farm-level preproduction trials, the last step before commercialization. farm surveys of randomly selected farm households that are cultivating the insect-resistant gm rice varieties, without the aid of experimental station technicians, demonstrate that when compared with households cultiv ... | 2005 | 15860626 |
| bt transgenic crops do not have favorable effects on resistant insects. | sayyed et al. (ecology letters (2003) 6: 167-169) hypothesized that insecticidal bacillus thuringiensis (bt) toxins produced by transgenic crops could have nutritionally favorable effects that increase the fitness of resistant insects eating such crops. this idea was based on increased pupal weight of resistant larvae of diamondback moth, plutella xylostella (l.), fed leaf discs treated externally with a bt toxin. we summarize evidence from diamondback moth and other pests showing that the bt to ... | 2004 | 15861220 |
| entomopathogenic fungi for mosquito control: a review. | fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. virtually all insect orders are susceptible to fungal diseases, including dipterans. fungal pathogens such as lagenidium, coelomomyces and culicinomyces are known to affect mosquito populations, and have been studied extensively. there are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. the discovery, in 1977, of the selective mosquito-pa ... | 2004 | 15861235 |
| development of bollworms, helicoverpa zea, on two commercial bollgard cultivars that differ in overall cry1ac levels. | research was conducted to quantify the development of the corn earworm (= bollworm), helicoverpa zea (boddie), on two different transgenic cotton cultivars (dp 50b and nucotn 33b) that contained different levels of the cry1ac endotoxin from the soil bacterium, bacillus thuringiensis berliner. using a field cage, an inverse relationship between the amount of cry1ac among cultivars versus the weight of bollworm larvae was observed. larvae that were recovered from the dp 50b cultivar expressing low ... | 2004 | 15861247 |
| detection of genetically modified corn (bt176) in spiked cow blood samples by polymerase chain reaction and immunoassay methods. | the fate of dna and protein transgenic sequences in products derived from animals fed transgenic crops has recently raised public interest. sensitive molecular tests targeting the bt176 genetic construct and the transgenic cry1ab protein were developed to determine whether plant sequences, especially transgenic sequences, are present in animal products. a protocol for total dna extraction and purification from cow whole blood samples was first drawn up and assessed by spiking with known amounts ... | 2005 | 15861534 |
| the linear double-stranded dna of phage bam35 enters lysogenic host cells, but the late phage functions are suppressed. | bam35, a temperate double-stranded dna bacteriophage with a 15-kb linear genome, infects gram-positive bacillus thuringiensis cells. bam35 morphology and genome organization resemble those of prd1, a lytic phage infecting gram-negative bacteria. bam35 and prd1 have an outer protein coat surrounding a membrane that encloses the viral dna. we used electrochemical methods to investigate physiological changes of the lysogenic and nonlysogenic hosts during bam35 dna entry and host cell lysis. during ... | 2005 | 15866940 |
| new resistance mechanism in helicoverpa armigera threatens transgenic crops expressing bacillus thuringiensis cry1ac toxin. | in australia, the cotton bollworm, helicoverpa armigera, has a long history of resistance to conventional insecticides. transgenic cotton (expressing the bacillus thuringiensis toxin cry1ac) has been grown for h. armigera control since 1996. it is demonstrated here that a population of australian h. armigera has developed resistance to cry1ac toxin (275-fold). some 70% of resistant h. armigera larvae were able to survive on cry1ac transgenic cotton (ingard) the resistance phenotype is inherited ... | 2005 | 15870346 |
| tolerance of bt corn (mon 810) to maize stem borer, chilo partellus (lepidoptera: pyralidae). | transgenic corn (mon 810), expressing the bacillus thuringiensis (bt) protein, cry1ab, was evaluated under greenhouse conditions for its tolerance to the maize stem borer, chilo partellus. bt corn (mon 810) provided effective protection against the stem borer even under a high level of larval infestation in the greenhouse. the observed tolerance is examined and discussed in the light of the susceptibility of c. partellus to the cry1ab protein in laboratory bioassays. the implications of the tiss ... | 2005 | 15875192 |
| discovery and utilization of qtls for insect resistance in soybean. | insect resistance in soybean has been an objective in numerous breeding programs, but efforts to develop high yielding cultivars with insect resistance have been unsuccessful. three japanese plant introductions, pis 171451, 227687 and 229358, have been the primary sources of insect resistance alleles, but a combination of quantitative inheritance of resistance and poor agronomic performance has hindered progress. linkage drag caused by co-introgression of undesirable agronomic trait alleles link ... | 2005 | 15881690 |
| assessment of cone-damaging insects in a swedish spruce seed orchard and the efficacy of large-scale application of bacillus thuringiensis variety aizawai x kurstaki against lepidopterans. | in a 2-yr study, we investigated the efficacy of large-scale application of the biological insecticide bacillus thuringiensis variety aizawai x kurstaki (btk) in a swedish spruce, picea abies l. (karst.), seed orchard for controlling damage caused by four lepidopteran species: dioryctria abietella den et. schiff. (pyralidae), eupithecia abietaria götze, e. analoga djakonov (geometridae), and cydia strobilella (l.) (tortricidae). the frequencies of these species, and strobilomyia anthracina czern ... | 2005 | 15889731 |
| hymenopteran parasitoids of diamondback moth (lepidoptera: ypeunomutidae) in northern thailand. | larvae of the diamondback moth, plutella xylostella (l.) (lepidoptera: ypeunomutidae), cause severe economic damage to cabbage, brassica oleracea l. variety capitata (brassicaceae) and related vegetables in thailand. overuse of broad-spectrum insecticides for diamondback moth control is a serious problem and has obscured the contributions of indigenous parasitoids. our objectives were to identify indigenous diamondback moth parasitoids in northern thailand and to assess their potential for natur ... | 2005 | 15889737 |
| effects of sublethal concentrations of bacillus thuringiensis on larval development of sesamia nonagrioides. | in the mediterranean basin, developed diapausing larvae of the borer sesamia nonagrioides lefèbvre are found consistently during autumn in transgenic corn, zea mays l., expressing bacillus thuringiensis berliner (bt) toxins derived from event 176. these larvae can feed on sublethal concentrations of bt toxins because the expression of this corn toxin declines after flowering. to evaluate the possible consequences of this phenomenon, the effect of sublethal concentrations of the natural toxin pro ... | 2005 | 15889739 |
| laboratory and field evaluations of transgenic soybean exhibiting high-dose expression of a synthetic bacillus thuringiensis cry1a gene for control of lepidoptera. | transgenic lines of soybean, glycine max (l.) merrill, expressing a synthetic cry1a gene (tic107) from bacillus thuringiensis (bt), were evaluated in screenhouse and conventional field trials for efficacy against lepidopteran pests. in screenhouse trials, bt soybean and negative checks (isogenic segregants and parental lines) were evaluated against anticarsia gemmatalis hübner and pseudoplusia includens (walker) in the united states and against a. gemmatalis, epinotia aporema (walsingham), rachi ... | 2005 | 15889751 |
| comprehensive assignment of mass spectral signatures from individual bacillus atrophaeus spores in matrix-free laser desorption/ionization bioaerosol mass spectrometry. | we have fully characterized the mass spectral signatures of individual bacillus atrophaeus spores obtained using matrix-free laser desorption/ionization bioaerosol mass spectrometry (bams). mass spectra of spores grown in unlabeled, 13c-labeled, and 15n-labeled growth media were used to determine the number of carbon and nitrogen atoms associated with each mass peak observed in mass spectra from positive and negative ions. to determine the parent ion structure associated with fragment ion peaks, ... | 2005 | 15889924 |
| many roads to resistance: how invertebrates adapt to bt toxins. | the cry family of bacillus thuringiensis insecticidal and nematicidal proteins constitutes a valuable source of environmentally benign compounds for the control of insect pests and disease agents. an understanding of cry toxin resistance at a molecular level will be critical to the long-term utility of this technology; it may also shed light on basic mechanisms used by other bacterial toxins that target specific organisms or cell types. selection and cross-resistance studies have confirmed that ... | 2005 | 15892110 |
| the synergistic activity between cry1aa and cry1c from bacillus thuringiensis against spodoptera exigua and helicoverpa armigera. | to investigate the interaction between two crystal proteins, cry1aa and cry1c, for future development of biopesticides based on bacillus thuringiensis, toxicities of the two individual proteins and in combinations have been determined against spodoptera exigua and helicoverpa armigera larvae, and synergism between the proteins has been evaluated using synergistic factor. | 2005 | 15892743 |
| is the mature endotoxin cry1ac from bacillus thuringiensis inactivated by a coagulation reaction in the gut lumen of resistant helicoverpa armigera larvae? | bacillus thuringiensis endotoxins (bt-toxins) are the most important biopesticides used in controlling insect pests and vectors of diseases. the emergence of widespread resistance to bt in some insect species is a serious threat to agricultural production. analysis of bt-resistant and susceptible laboratory strains of helicoverpa armigera revealed elevated immune responses involving increased melanization and the presence of a soluble toxin-binding glycoprotein in the hemolymph and gut lumen of ... | 2005 | 15894190 |
| crystallization and preliminary crystallographic analysis of bacillus thuringiensis ahl-lactonase. | the quorum sensing (qs) systems in gram-negative bacteria are mostly associated with diffusible n-acyl-l-homoserine lactones (ahls). ahl-degrading enzymes hydrolyze the ahls into inactive molecules, thereby blocking the qs systems that are closely linked to virulence factor production and biofilm formation. consequently, these enzymes have recently attracted intense interest for the development of anti-infection therapies for plants and animals. however, despite significant progress in the inves ... | 2005 | 15894524 |
| the quorum-quenching lactonase from bacillus thuringiensis is a metalloprotein. | lactonases from bacillus species hydrolyze the n-acylhomoserine lactone (ahl) signaling molecules used in quorum-sensing pathways of many gram-negative bacteria, including pseudomonas aeruginosa and erwinia carotovora, both significant pathogens. because of sequence similarity, these ahl lactonases have been assigned to the metallo-beta-lactamase superfamily of proteins, which includes metalloenzymes of diverse activity, mechanism, and metal content. however, a recent study claims that ahl lacto ... | 2005 | 15895999 |
| diversity of alternative hosts of maize stemborers in trans-nzoia district of kenya. | genetically-engineered (ge) crops such as those expressing insecticidal bacillus thuringiensis (bt) toxin genes have the potential to greatly reduce the use of broad spectrum insecticides and increase crop productivity. however, development of resistance by the target insect species is an important consideration in the deployment of this strategy. in areas where ge crops are deployed on a large scale, current resistance management strategies rely on a 'refuge strategy', comprising the incorporat ... | 2004 | 15901098 |
| [transfer of insecticidal protein gene from bacillus thuringiensis into conventional maize inbred-line mediated by agrobacterium tumefaciens]. | excellent inbred-lines of maize,340 and 4112, which were used largely in hybridized combination were transformed with agrobacterium tumefaciens. the immature embryos and their original calli were infected by a.tumefaciens lba4404 containing plasmid pgbil04. after 3 days of co-cultivation, the immature embryos and calli were continuously selected on the medium containing phosphinothricin (ppt) for 3 generations, then plants were regenerated. it was proved by pcr analysis that the target bt gene h ... | 2002 | 15901560 |
| comparison of the localization of bacillus thuringiensis cry1a delta-endotoxins and their binding proteins in larval midgut of tobacco hornworm, manduca sexta. | tobacco hornworm, manduca sexta, is a model insect for studying the action of bacillus thuringiensis (bt) cry toxins on lepidopterans. the proteins, which bind bt toxins to midgut epithelial cells, are key factors involved in the insecticidal functions of the toxins. three cry1a-binding proteins, viz., aminopeptidase n (apn), the cadherin-like bt-r1, and membrane-type alkaline phosphatase (m-alp), were localized, by immunohistochemistry, in sections from the anterior, middle, and posterior regio ... | 2005 | 15902495 |
| rotational application of bioinsecticide with deltamethrin-an antilarval measure for the control of filarial vector, culex quinquefasciatus (culicidae: diptera). | a laboratory investigation was undertaken to study the cyclic usage of field recommended doses of bacillus thuringiensis israelensis (bti), bacillus sphaericus (bsp) and combination of bti and bsp (half the recommended dose of each) with deltamethrin 2.8 ec to attain better control of mosquito larvae. to understand the susceptibility status of the culex quinquefasciatus larvae in the field, early fourth instar field collected larvae were exposed to the above treatments of biopesticides and were ... | 2004 | 15907070 |
| an alternative strategy for sustainable pest resistance in genetically enhanced crops. | bacillus thuringiensis (bt) crystal protein genes encode insecticidal delta-endotoxins that are widely used for the development of insect-resistant crops. in this article, we describe an alternative transgenic strategy that has the potential to generate broader and more sustainable levels of resistance against insect pests. our strategy involves engineering plants with a fusion protein combining the delta-endotoxin cry1ac with the galactose-binding domain of the nontoxic ricin b-chain (rb). this ... | 2005 | 15908504 |
| efficacy of a new formulation of bacillus thuringiensis var israelensis (bti) in laboratory and field conditions of kumaun foothills of uttaranchal, india. | efficacy of a new bti formulation was tested in the laboratory and small scale field trials against mosquito larvae were carried out from march to june, 2001 in different breeding habitats of kumaun foothill region of nainital and udham singh nagar districts, uttaranchal state, india. laboratory tests revealed increased efficacy against culex quinquefasciatus (lc50 = 0.035 mg/l) followed by aedes aegypti (lc50 = 0.0628 mg/l), an. culicifacies sp a (lc50 = 0.184mg/l) and an. stephensi (lc50 - 0.2 ... | 2003 | 15909759 |
| toxicity of several delta-endotoxins of bacillus thuringiensis against helicoverpa armigera (lepidoptera: noctuidae) from spain. | toxicity and larval growth inhibition of 11 insecticidal proteins of bacillus thuringiensis were evaluated against neonate larvae of helicoverpa armigera, a major pest of important crops in spain and other countries, by a whole-diet contamination method. the most active toxins were cry1ac4 and cry2aa1, with lc50 values of 3.5 and 6.3 microg/ml, respectively. at the concentrations tested, cry1ac4, cry2aa1, cry9ca, cry1fa1, cry1ab3, cry2ab2, cry1da, and cry1ja1, produced a significant growth inhib ... | 2005 | 15913643 |
| cytotoxicity of bacillus thuringiensis cry1ab toxin depends on specific binding of the toxin to the cadherin receptor bt-r1 expressed in insect cells. | the specific role of cadherin receptors in cytotoxicity involving cry toxins of bacillus thuringiensis and their interactions with cell membrane has not been defined. to elucidate the involvement of toxin-membrane and toxin-receptor interactions in cytotoxicity, we established a cell-based system utilizing high five insect cells stably expressing bt-r1, the cadherin receptor for cry1ab toxin. cry1ab toxin is incorporated into cell membrane in both oligomeric and monomeric form. monomeric toxin b ... | 2005 | 15920532 |
| a simple purification and activity assay of the coagulant protein from moringa oleifera seed. | use of extracts from moringa oleifera (mo) is of great interest for low-cost water treatment. this paper discusses water and salt extraction of a coagulant protein from the seed, purification using ion exchange, its chemical characteristics, coagulation and antimicrobial properties. the coagulant from both extracts is a cationic protein with pi greater than 9.6 and molecular mass less than 6.5 kda. mass spectrometric analysis of the purified water extract indicated that it contained at least fou ... | 2005 | 15921719 |
| regulating insect resistance management: the case of non-bt corn refuges in the us. | in this paper, we analyze the insect resistance management (irm) plan put in place by the us environmental protection agency (epa) to delay the evolution of resistance to bt corn in natural populations of the european corn borer, ostrinia nubilalis hübner. this irm plan is the most impressive mandatory irm system ever developed. it forms a coherent whole and includes mandatory refuges, actions to increase growers' compliance and a program for monitoring the evolution of resistance. however, our ... | 2005 | 15922504 |
| evolutionary trade-offs of insect resistance to bacillus thuringiensis crops: fitness cost affecting paternity. | evolution of resistance to insecticides provides a useful model for examining fitness trade-offs associated with adaptation to stress. here, we examined male reproductive costs in pink bollworm (pectinophora gossypiella) resistant to an insecticidal protein of bacillus thuringiensis (bt) produced by transgenic cotton, using contrasts between two pairs of related susceptible and resistant strains. without competition for access to females, no costs affecting reproductive success of resistant male ... | 2005 | 15926701 |
| novel genetic basis of field-evolved resistance to bt toxins in plutella xylostella. | insecticidal toxins from bacillus thuringiensis (bt) are widely used to control pest insects, but evolution of resistance threatens their continued efficacy. the most common type of bt resistance ('mode 1') is characterized by recessive inheritance, > 500-fold resistance to at least one cry1a toxin, negligible cross-resistance to cry1c, and reduced binding of bt toxins to midgut membrane target sites. mutations affecting a cry1a-binding midgut cadherin protein are linked to laboratory-selected m ... | 2005 | 15926902 |
| identification of a promoter for the vegetative insecticidal protein-encoding gene vip3lb from bacillus thuringiensis. | the expression of vip3lb, one of the vegetative insecticidal protein-encoding genes of bacillus thuringiensis, was studied at the transcriptional level. by primer extension analysis, we have identified, for the first time, the transcription start point of vip3-type gene. upstream from vip3lb transcription start point, was found a nucleotide sequence partially homologous to the consensus sequence for the e sigma(e) holoenzyme of b. subtilis. thus, it was strongly suggested that the identified vip ... | 2005 | 15927753 |
| dielectric monitoring of growth and sporulation of bacillus thuringiensis. | on-line permittivity and optical density measurements have been used to monitor biomass concentration and sporulation status during growth of a spore-forming bacterium, bacillus thuringiensis, in fed-batch culture. the correlation between permittivity, optical density and other observations showed three distinct phases of growth: growth itself, transition and sporulation. the permittivity variations during the transition and sporulation phases could be related to the sporulation development: the ... | 2005 | 15928859 |
| cloning and expression of mel gene from bacillus thuringiensis in escherichia coli. | previous work from our laboratory has shown that most of bacillus thuringiensis strains possess the ability to produce melanin in the presence of l -tyrosine at elevated temperatures (42 degrees c). furthermore, it was shown that the melanin produced by b. thuringiensis was synthesized by the action of tyrosinase, which catalyzed the conversion of l -tyrosine, via l -dopa, to melanin. in this study, the tyrosinase-encoding gene (mel) from b. thuringiensis 4d11 was cloned using pcr techniques and ... | 2005 | 15928981 |
| surface display of recombinant proteins on bacillus thuringiensis spores. | the insecticidal protoxin from bacillus thuringiensis has been shown to be a major component of the spore coat. we have developed a novel surface display system using b. thuringiensis spores in which the n-terminal portion of the protoxin is replaced with a heterologous protein. the expression vector with a sporulation-specific promoter was successfully used to display green fluorescent protein and a single-chain antibody (scfv) gene that encodes anti-4-ethoxymethylene-2-phenyl-2-oxazolin-5-one ... | 2005 | 15933037 |
| concurrent use of transgenic plants expressing a single and two bacillus thuringiensis genes speeds insect adaptation to pyramided plants. | transgenic plants expressing insecticidal proteins from the bacterium bacillus thuringiensis (bt) were grown on over 13 million ha in the united states and 22.4 million ha worldwide in 2004. preventing or slowing the evolution of resistance by insects ("resistance management") is critical for the sustainable use of bt crops. plants containing two dissimilar bt toxin genes in the same plant ("pyramided") have the potential to delay insect resistance. however, the advantage of pyramided bt plants ... | 2005 | 15939892 |
| environmental fate and effects of bacillus thuringiensis (bt) proteins from transgenic crops: a review. | this paper reviews the scientific literature addressing the environmental fate and nontarget effects of the cry protein toxins from bacillus thuringiensis (bt), specifically resulting from their expression in transgenic crops. published literature on analytical methodologies for the detection and quantification of the cry proteins in environmental matrices is also reviewed, with discussion of the adequacy of the techniques for determining the persistence and mobility of the bt proteins. in gener ... | 2005 | 15941295 |
| identification of cry-type genes on 20-kb dna associated with cry1 crystal proteins from bacillus thuringiensis. | heterologous dna fragments (20-kb) associated with cry1 crystal proteins (protoxins) from a soil-isolated bacillus thuringiensis strain 4.0718 were isolated and analyzed. rflp patterns of the pcr products showed that the 20-kb dna fragments harbored cry1aa, cry1ac, cry2aa, and cry2ab genes. furthermore, a 4.2-kb dna fragment, which contained the promoter, the coding region, and the terminator of cry1ac gene, was cloned from the 20-kb dnas by pcr, and then the cry1ac gene was expressed in an acry ... | 2005 | 15942699 |
| characterization of cdnas encoding three trypsin-like proteinases and mrna quantitative analysis in bt-resistant and -susceptible strains of ostrinia nubilalis. | our previous studies suggested that bacillus thuringiensis (bt) resistance in a dipel-resistant strain of ostrinia nubilalis was primarily due to reduced trypsin-like proteinase activity. in this study, we demonstrated a 254-fold resistance to cry1ab protoxin but only 12-fold to trypsin-activated cry1ab toxin in the dipel-resistant strain. significantly higher resistance to cry1ab protoxin than to trypsin-activated cry1ab toxin further supports the hypothesis that reduced trypsin-like proteinase ... | 2005 | 15944081 |
| phosphatidylinositol-specific phospholipase c of bacillus anthracis down-modulates the immune response. | phosphatidylinositol-specific phospholipases (pi-plcs) are virulence factors produced by many pathogenic bacteria, including bacillus anthracis and listeria monocytogenes. bacillus pi-plc differs from listeria pi-plc in that it has strong activity for cleaving gpi-anchored proteins. treatment of murine dcs with bacillus, but not listeria, pi-plc inhibited dendritic cell (dc) activation by tlr ligands. infection of mice with listeria expressing b. anthracis pi-plc resulted in a reduced ag-specifi ... | 2005 | 15944308 |
| expanding the bactericidal action of the food color additive phloxine b to gram-negative bacteria. | phloxine b (d&c red no. 28) is a color additive for food, drugs, and cosmetics. it has been previously shown to have anti-staphylococcus aureus activities. in this work, the effect of phloxine b on various gram-negative bacteria and other gram-positive bacteria including bacillus cereus, bacillus thuringiensis, bacillus mycoides, bacillus subtilis, bacillus aureus, salmonella, escherichia coli and shigella was studied, along with the mechanism of anti-microbial activity. in the presence of fluor ... | 2005 | 15949926 |
| construction of a pseudomonas sp. derivative carrying the cry9aa gene from bacillus thuringiensis and a proposal for new standard criteria to assess entomocidal properties of bacteria. | an isolate of pseudomonas sp. (16s rdna sequence 98% homologous to p. graminis and p. lutea) was isolated from the phyllosphere of black pine in northern italy and used as a host for the gene encoding the cry9aa entomocidal toxin from bacillus thuringiensis subsp. galleriae. an expression system featuring a synthetic highest-consensus promoter specifically tailored for the regulated induction of cloned genes over a broad range of gram-negative bacteria was used to drive the production of the int ... | 2005 | 15950125 |
| a cryptic bacillus isolate exhibited narrow 16s rrna gene sequence divergence with bacillus thuringiensis and showed low maintenance requirements in hyper-osmotic complex substrate cultivations. | a cryptic bacillus (k90) isolate obtained from soil samples from the kuwait desert exhibited lower maintenance requirements in complex substrate cultivations than bacillus thuringiensis. a mathematical model was used to estimate apparent maintenance coefficients (m(c)) and these were found to be 0.336 and 0.041/h for b. thuringiensis and k90, respectively. the results also showed that the values of apparent maintenance coefficients were inversely related to the specific growth rates. furthermore ... | 2005 | 15959906 |
| laboratory studies of the effects of reduced prey choice caused by bt plants on a predatory insect. | crops transformed to express bacillus thuringiensis (bt) toxins can cause close to 100% mortality of certain target pest species. this study assessed the effect of target pest reduction on the predatory insect chrysoperla carnea (stephens) in the presence of alternative prey. numbers of lacewings recovered from bt oilseed rape (cultivar oscar, event o52) did not differ significantly from numbers of lacewings recovered from conventional oilseed rape in cage experiments with the target pest plutel ... | 2005 | 15960878 |
| synthesis of additional endotoxins in bacillus thuringiensis subsp. morrisoni pg-14 and bacillus thuringiensis subsp. jegathesan significantly improves their mosquitocidal efficacy. | a fundamental principal of resistance management is that the more complex and potent a toxin mixture, the slower resistance will develop to the mixture in an insect population. thus, to develop more complex and potent mosquitocidal bacteria, we genetically engineered bacillus thuringiensis subsp. morrisoni pg-14 and bacillus thuringiensis subsp. jegathesan, to synthesize, respectively, the binary (bin) toxin of bacillus sphaericus or a combination of bin and the cytla protein of bacillus thuring ... | 2005 | 15962784 |
| cry11aa toxin from bacillus thuringiensis binds its receptor in aedes aegypti mosquito larvae through loop alpha-8 of domain ii. | bacillus thuringiensis subs israelensis produces cry toxins active against mosquitoes. receptor binding is a key determinant for specificity of cry toxins composed of three domains. we found that exposed loop alpha-8 of cry11aa toxin, located in domain ii, is an important epitope involved in receptor interaction. synthetic peptides corresponding to exposed regions in domain ii (loop alpha-8, beta-4 and loop 3) competed binding of cry11aa to membrane vesicles from aedes aegypti midgut microvilli. ... | 2005 | 15963509 |
| toxicity of bacillus thuringiensis to parasitic and free-living life-stages of nematode parasites of livestock. | a collection of bacillus thuringiensis (bt) strains (bts) were screened for activity against the free-living larval stages of nematode parasites of livestock. two strains were identified with significant activity in inhibiting larval development of haemonchus contortus, trichostrongylus colubriformis and ostertagia circumcincta. these strains were also toxic to the adult parasitic stages of these nematode species in vitro. adult h. contortus and o. circumcincta showed complete cessation of movem ... | 2005 | 15964574 |
| recombinant larvicidal bacteria with markedly improved efficacy against culex vectors of west nile virus. | an urgent need exists for new agents to control mosquito vectors of disease. mosquito larvicides based on the bacteria bacillus thuringiensis subsp. israelensis (bti) or b. sphaericus (bs) are effective in many habitats, but use is limited by their high cost. moreover, mosquito resistance evolves rapidly to bs where it is used intensively. the efficacy of these bacteria is due to a binary protein (bsb) in bs and four proteins (cry4a, cry4b, cry11a, and cyt1a) in bti. here we report the use of cy ... | 2005 | 15964958 |
| using worms to better understand how bacillus thuringiensis kills insects. | bacillus thuringiensis is widely used as a biological pesticide to control insects that either cause damage to crops or transmit disease. that it can also target the model organism caenorhabditis elegans has not only provided exciting new insights into how the toxins produced by the bacterium target their victims but also how target insects counter the attack. modern approaches such as reverse genetics and microarray technology have revealed novel receptors for the toxins and possible signal tra ... | 2005 | 15967665 |
| [expression of gene aiia carrying the promoter of gene cry3aa in bacillus thuringiensis]. | n-acyl-homoserine lactones (ahls), are widely conserved signal molecules present in quorum-sensing systems of many gram-negative bacteria. ahls molecules mediate the expression of virulence genes of a range of bacterial pathogens. recently, it has been reported that aiia protein, which widely exists in bacillus species, can inactivate the ahls by hydrolyzing the lactone bond of ahls, thus attenuate the diseases caused by the expression of virulence genes of bacterial pathogens. bacillus thuringi ... | 2003 | 15969053 |
| [screening of bacillus thuringiensis strains containing vip3a genes and analysis of gene conservation]. | vip3a, a novel insecticidal protein, is secreted by bacillus thuringiensis (bt) during vegetative growth. vip3a protein possesses insecticidal activity against a wild spectrum of lepidopteran insect larvae. since the first cloning of vip3a gene from bt, many other vip3a genes have been isolated. to investigate vip3a genes contribution to bt and reflect the revolution relationships, the strains containing vip3a genes were screened and gene similarity was analyzed. 114 wild-type bacillus thuringie ... | 2003 | 15969080 |