Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [obtaining stem borer-resistant homozygous transgenic lines of minghui 81 harboring novel cry1ac gene via particle bombardment]. | a modified cry1ac gene was generated by fusing with lys-asp-glu-lue (kdel), an endoplasmic reticulum retention signal at the 3'-ends, with signal peptide coding sequence of soybean kunitz trypsin inhibitor (skti) at the 5'-ends. vector containing the modified cry1ac gene coding region flanked by the corn ubiquitin 1 promoter and the nopaline synthase gene (nos) terminator with hygromycin phosphotransferase (hpt) gene as a plant selection marker was constructed. the modified cry1ac gene in which ... | 2002 | 12096630 |
| molecular characterization of local bacillus thuringiensis strains recovered from northern jordan. | a total of 80 isolates of bacillus thuringiensis were recovered from different habitats of northern jordan. these isolates were grouped into three classes based on crystal morphology (spherical, bipyramidal, and both bipyramidal and cuboidal). the isolates that produced spherical crystals were the most common and the most toxic to diptera. sds-page analysis of the isolates and some reference strains with similar crystal morphology showed similar protein profiles with heterogeneous multiple prote ... | 2002 | 12111742 |
| two-dimensional electrophoresis analysis of the extracellular proteome of bacillus cereus reveals the importance of the plcr regulon. | many virulence factors are secreted by the gram-positive, spore forming bacterium bacillus cereus. most of them are regulated by the transcriptional activator, plcr, which is maximally expressed at the beginning of the stationary phase. we used a proteomic approach to study the impact of the plcr regulon on the secreted proteins of b. cereus, by comparing the extracellular proteomes of strains atcc 14579 and atcc 14579 delta plcr, in which plcr has been disrupted. our study indicated that, quant ... | 2002 | 12112862 |
| extremely high frequency of common flagellar antigens between bacillus thuringiensis and bacillus cereus. | bacillus cereus isolates, recovered from natural environments of japan, were examined for their flagellar (h) antigenicities with the reference h antisera against bacillus thuringiensis serotypes h1-h55. of 236 b. cereus isolates tested, 165 (70%) were agglutinated with the reference antisera available. the frequencies of seropositive isolates were: 77% in soils, 68% on phylloplanes, and 60% in animal fecal populations. among the 45 h serogroups detected, the serovar shandongiensis (h22) was the ... | 2002 | 12127494 |
| usefulness of staining parasporal bodies when screening for bacillus thuringiensis. | 2002 | 12133711 | |
| detection and quantification of transgenes in grains by multiplex and real-time pcr. | multiplex pcr reactions were developed for detecting simultaneously the cryia(b) and pat genes from events 176, mon810, bt11, and t25 of transgenic maize, using only two pairs of primers, one for the cryia(b) gene and the other for the pat gene. the roundup ready soybean can be precisely detected by a multiplex pcr reaction using known primers, amplifying fragments of the nos and the epsps sequences simultaneously. transgenic events such as roundup ready soybean and ga21 maize, among others, can ... | 2002 | 12137456 |
| ultrasensitive detection of genetically modified maize dna by capillary gel electrophoresis with laser-induced fluorescence using different fluorescent intercalating dyes. | in this work, four different fluorescent intercalating dyes are compared for the ultrasensitive cge-lif detection of dna from transgenic maize in flours. the fluorescent intercalating dyes compared are yopro-1, sybr-green-i, ethidium bromide (ethbr), and enhance. for all the four dyes optimum concentrations are established, and efficient separations of dna fragments ranging in size from 80 to 1000 bp are obtained. the comparative study demonstrates that sybr-green-i and yopro-1 provide better li ... | 2002 | 12137467 |
| combined analysis of supernatant-based feeding bioassays and pcr as a first-tier screening strategy for vip -derived activities in bacillus thuringiensis strains effective against tropical fall armyworm. | to assess whether feeding bioassays using culture-supernatant proteins could be combined with pcr into a first-tier screening strategy for vip3a-like genes efficient against tropical spodoptera frugiperda. | 2002 | 12147075 |
| control of resistant pink bollworm (pectinophora gossypiella) by transgenic cotton that produces bacillus thuringiensis toxin cry2ab. | crops genetically engineered to produce bacillus thuringiensis toxins for insect control can reduce use of conventional insecticides, but insect resistance could limit the success of this technology. the first generation of transgenic cotton with b. thuringiensis produces a single toxin, cry1ac, that is highly effective against susceptible larvae of pink bollworm (pectinophora gossypiella), a major cotton pest. to counter potential problems with resistance, second-generation transgenic cotton th ... | 2002 | 12147473 |
| genes encoding the n-acyl homoserine lactone-degrading enzyme are widespread in many subspecies of bacillus thuringiensis. | gram-negative bacteria can communicate with each other by n-acyl homoserine lactones (ahls), which are quorum-sensing autoinducers. recently, the aiia gene (encoding an enzyme catalyzing the degradation of ahl) has been cloned from bacillus sp. strain 240b1. during investigations in the course of the ongoing bacillus thuringiensis subsp. morrisoni genome project, an aiia homologue gene in the genome sequence was found. these results led to consideration of the possibility of the widespread exist ... | 2002 | 12147491 |
| extent of variation of the bacillus thuringiensis toxin reservoir: the case of the geranium bronze, cacyreus marshalli butler (lepidoptera: lycaenidae). | despite the fact that around 200 cry genes from bacillus thuringiensis have already been cloned, only a few cry proteins are toxic towards a given pest. a crucial step in the mode of action of cry proteins is binding to specific sites in the midgut of susceptible insects. binding studies in insects that have developed cross-resistance discourage the combined use of cry proteins sharing the same binding site. if resistance management strategies are to be implemented, the arsenal of cry proteins s ... | 2002 | 12147511 |
| responses of songbirds to aerial spraying of the microbial insecticide bacillus thuringiensis var. kurstaki (foray 48b) on vancouver island, british columbia, canada. | use of bacterial insecticides containing bacillus thuringiensis var. kurstaki (btk) is gaining popularity as an environmentally safe control measure against lepidopteran pests, but indirect effects on nontarget organisms through reduced prey base have received little attention. aerial spraying of btk (foray 48b) over a 12,803-ha area on southeastern vancouver island (bc, canada) in may to june 1999 as part of a gypsy moth (lymantria dispar) control program provided us with an opportunity to exam ... | 2002 | 12152767 |
| 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 |
| field evaluation of bacillus thuringiensis var. israelensis (bacticide) against anopheles stephensi breeding in calcutta city. | 2001 | 12170935 | |
| chitinolytic activities in bacillus thuringiensis and their synergistic effects on larvicidal activity. | to investigate the distribution of chitinase in bacillus thuringiensis strains, and the enhancing effects of the chitinase-producing b. thuringiensis strains on insecticidal toxicity of active b. thuringiensis strain against spodoptera exigua larvae. | 2002 | 12174034 |
| protection from uv-b damage of mosquito larvicidal toxins from bacillus thuringiensis subsp. israelensis expressed in anabaena pcc 7120. | a transgenic strain of the nitrogen-fixing filamentous cyanobacterium anabaena pcc 7120 protected expressed delta-endotoxin proteins of bacillus thuringiensis subsp. israelensis from damage inflicted by uv-b, a sunlight component that penetrates earth's ozone layer. this organism, which serves as a food source to mosquito larvae and could multiply in their breeding sites, may solve the environment-imposed limitations of b. thuringiensis subsp. israelensis as a mosquito biological control agent. | 2002 | 12177745 |
| detection of enterotoxin genes in mosquito-larvicidal bacillus species. | the presence of the b component of hemolysin bl (hbla), enterotoxin bcet (bcet), and enterotoxin s (ents) genes in mosquito-larvicidal bacillus sp., including 25 b. sphaericus and 4 b. thuringiensis subsp. israelensis strains, has been analyzed by multiplex pcr in this study. the results showed that all four b. thuringiensis strains contain the hbla gene and the sequences of bcet and ents genes. however, none of the enterotoxin gene sequences were detected in the b. sphaericus strains. the enter ... | 2002 | 12177746 |
| five years of bt cotton in china - the benefits continue. | bt cotton is spreading very rapidly in china, in response to demand from farmers for technology that will reduce both the cost of pesticide applications and exposure to pesticides, and will free up time for other tasks. based on surveys of hundreds of farmers in the yellow river cotton-growing region in northern china in 1999, 2000 and 2001, over 4 million smallholders have been able to increase yield per hectare, and reduce pesticide costs, time spent spraying dangerous pesticides, and illnesse ... | 2002 | 12182701 |
| [influence of composition of the nutrient medium on growth and development of entomopathogenic bacteria bacillus thuringiensis]. | new medium for cultivation of bacillus thuringiensis has been elaborated with the help of a simplex method for mathematical planning the experiment. the optimized medium containing green syrup, corn extract, sodium humate and mineral salts, allowed to increase the biomass titer by 45%, endotoxin by 220% as compared to the initial medium. insecticide activity of bacillus thuringiensis culture grown on the new culture medium exceeds considerably that on the initial culture medium. | 2002 | 12190024 |
| [detection and identification of the transgenes in genetically modified plants on the example of bt-potato]. | we have developed diagnostic system for revealing 35s promoter camv and transgene cryiiia in transgenic potato nl russet burbank and nl superior companies monsanto. using the data about nucleotide sequences of 35s promoter (af234316 genbank) and gene cryiiia (x70979 genbank) oligonucleotides primers were synthesized for polymerase chain reaction (pcr). the technique of genomic dna isolation from plant material, suitable for pcr has been optimized. using touchdown pcr method presence of specific ... | 2002 | 12190031 |
| isolation and characterization of a strain of bacillus thuringiensis ssp. kurstaki containing a new delta-endotoxin gene. | a strain of bacillus thuringiensis that showed significantly high toxicity to plutella xylostella and spodoptera exigua was isolated from a korean soil sample and characterized. the isolate, named b. thuringiensis k1, was determined to belong to ssp. kurstaki (h3a3b3c) type by an h antisera agglutination test and produced bipyramidal inclusions. plasmid pattern of k1 was different from that of the reference strain, ssp. kurstaki hd-1, but the parasporal inclusion protein profile of k1 had two ma ... | 2002 | 12192530 |
| [a novel resolution vector with bacillus thuringiensis plasmid replicon ori44]. | the resolution recognization sites of transposon tn4430 of bacillus thuringiensis was inserted into cloning vector prset b and puc19, resulting recombinant plasmids pbmb1201 and pbmb1202. both of the mini res fragments, bamhi/hindiii fragment in pbmb1201 and ecori/hindiii fragment in pbmb1202, were ligated to the 3.3 kb ecori/hindiii fragment of shuttle vector pht3101, which contained the ori. ec, ampr and emr antibiotic resistant genes, resulting recombinant plasmid pbmb1203. after deleted the ... | 2002 | 12192869 |
| high level methoprene resistance in the mosquito ochlerotatus nigromaculis (ludlow) in central california. | in the summer of 1998, failures of methoprene field applications to control the mosquito ochlerotatus nigromaculis (ludlow) were noticed in several pastures in the outskirts of fresno, california, usa. effective control with methoprene had been achieved for over 20 years prior to this discovery. susceptibility tests indicated that the fresno oc nigromaculis populations had developed several thousand-fold higher lc50 and lc90 tolerance levels to methoprene compared with methoprene-naïve populatio ... | 2002 | 12192903 |
| a cell-cell signaling peptide activates the plcr virulence regulon in bacteria of the bacillus cereus group. | plcr is a pleiotropic regulator that activates the expression of genes encoding various virulence factors, such as phospholipases c, proteases and hemolysins, in bacillus thuringiensis and bacillus cereus. here we show that the activation mechanism is under the control of a small peptide: papr. the papr gene belongs to the plcr regulon and is located 70 bp downstream from plcr. it encodes a 48-amino-acid peptide. disruption of the papr gene abolished expression of the plcr regulon, resulting in ... | 2002 | 12198157 |
| correspondence of high levels of beta-exotoxin i and the presence of cry1b in bacillus thuringiensis. | examination of 640 natural isolates of bacillus thuringiensis showed that the 58 strains (9%) whose supernatants were toxic to anthonomus grandis (coleoptera: curculionidae) produced between 10 and 175 micro g of beta-exotoxin i per ml. we also found that 55 (46%) of a sample of 118 strains whose culture supernatants were not toxic to a. grandis nevertheless produced between 2 and 5 micro g/ml. however, these amounts of beta-exotoxin i were below the threshold for detectable toxicity against thi ... | 2002 | 12200263 |
| interaction of gene-cloned and insect cell-expressed aminopeptidase n of spodoptera litura with insecticidal crystal protein cry1c. | insecticidal toxins produced by bacillus thuringiensis interact with specific receptors located in the midguts of susceptible larvae, and the interaction is followed by a series of biochemical events that lead to the death of the insect. in order to elucidate the mechanism of action of b. thuringiensis toxins, receptor protein-encoding genes from many insect species have been cloned and characterized. in this paper we report the cloning, expression, and characterization of cry toxin-interacting ... | 2002 | 12200317 |
| [sequence analysis of bt insertion flanking fragments in transgenic bt cotton]. | the copies of outside gene and dna structure of integration locus are important in high expression and avoidance of gene silence. many research results showed that outside genes were inserted into the plant genome with recombinant type, and the integration was related to border t-dna sequence in the course of agrobaterium mediated transformation. sar structure was also found in the integration location of transformants with direct dna transformation method. the pollen-tube pathway transformation ... | 2002 | 12200866 |
| efficacy of a floating sustained release formulation of bacillus thuringiensis ssp. israelensis in controlling culex quinquefasciatus larvae in polluted water habitats. | larvicidal efficacy and residual activity of a floating sustained release formulation of bacillus thuringiensis ssp. israelensis (bti) was tested in polluted water habitats against culex quinquefasciatus, the vector of bancroftian filariasis, breeding in cesspools and cesspits. a total of 25 habitats having 65 m(2) water surface area with c. quinquefasciatus immatures were treated with the formulation at the rate of 15 kg/ha. for comparison, in another area, 18 habitats with a water surface area ... | 2002 | 12204397 |
| elite indica transgenic rice plants expressing modified cry1ac endotoxin of bacillus thuringiensis show enhanced resistance to yellow stem borer (scirpophaga incertulas). | bt-transgenics of elite indica rice breeding lines (ir-64, pusa basmati-1 and karnal local) were generated through biolistic or agrobacterium-mediated approaches. a synthetic cry1ac gene, codon optimised for rice and driven by the maize ubiquitin-1 promoter, was used. over 200 putative transformants of ir-64 and pusa basmati-1 and 26 of the karnal local were regenerated following use of the hpt (hygromycin phosphotransferase) selection system. initial transformation frequency was in the range of ... | 2002 | 12212843 |
| cry1a toxins of bacillus thuringiensis bind specifically to a region adjacent to the membrane-proximal extracellular domain of bt-r(1) in manduca sexta: involvement of a cadherin in the entomopathogenicity of bacillus thuringiensis. | many subspecies of the soil bacterium bacillus thuringiensis produce various parasporal crystal proteins, also known as cry toxins, that exhibit insecticidal activity upon binding to specific receptors in the midgut of susceptible insects. one such receptor, bt-r(1) (210 kda), is a cadherin located in the midgut epithelium of the tobacco hornworm, manduca sexta. it has a high binding affinity (k(d) approximately 1nm) for the cry1a toxins of b. thuringiensis. truncation analysis of bt-r(1) reveal ... | 2002 | 12213239 |
| comparative study on the effect of two bacillus thuringiensis strains of the same serotype on three coleopteran pests of stored wheat. | the biological control of insect populations of stored products by insect pathogens such as, bacillus thuringiensis (berliner) is considered as an alternative to synthetic insecticides. so far, only b. thuringiensis among microbial pesticides have been approved for application against stored product insect pests. in this study we used a laboratory culture from an indigenous isolate of b. thuringiensis subsp. morrisoni, and the commercial formulation, b. thuringiensis subsp. tenebrionis. the bioa ... | 2002 | 12214919 |
| behavior of bollworm (lepidoptera: noctuidae) larvae on genetically engineered cotton. | reports of bollworm, helicoverpa zea (boddie), larvae feeding in white flowers of bollgard cotton have been relatively common since the commercialization of this technology in 1996. field studies were conducted in louisiana to determine if differences in bollworm larval behavior occuron non-bollgard (cultivar 'deltapine 5415') and bacillus thuringiensis (bt), bollgard ('nucotn 33b') cottons. larvae were placed on the terminal foliage of either single cotton plants or on all plants within 1-m row ... | 2002 | 12216818 |
| resistance monitoring of helicoverpa armigera (lepidoptera noctuidae) to bacillus thuringiensis insecticidal protein in china. | sensitivities of helicoverpa armigera (hübner) field populations to bacillus thuringiensis (bt) insecticidal protein crylac were monitored during 1998-2000 in china. a total of 41 strains was sampled, and most of them were collected from bt cotton planting regions. the range of ic50 values (concentration producing 50% inhibition of larval development to third instar) among different populations in 1998,1999, and 2000 were 0.020-0.105 microg/ml, 0.016-0.099 microg/ml, and 0.016-0.080 microg/ml, r ... | 2002 | 12216827 |
| evaluation of the natural refuge function for helicoverpa arnigera (lepidoptera: noctuidae) within bacillus thuringiensis transgenic cotton growing areas in north china. | the density of helicoverpa armigera (hübner) populations on bacillus thuringiensis berliner (bt) transgenic cotton, corn, peanut, and soybean; differences in its development on bt cotton and common (nontransgenic) cotton; and the potential for mating among populations from bt cotton fields and other crop fields were investigated in the suburbs of xinxiang city (henan province) and langfang city (hebei province) in the southern and northern parts of north china, respectively. although development ... | 2002 | 12216828 |
| loss of catabolite repression function of hpr, the phosphocarrier protein of the bacterial phosphotransferase system, affects expression of the cry4a toxin gene in bacillus thuringiensis subsp. israelensis. | hpr, the phosphocarrier protein of the bacterial phosphotransferase system, mediates catabolite repression of a number of operons in gram-positive bacteria. in order to participate in the regulatory process, hpr is activated by phosphorylation of a conserved serine-46 residue. to study the potential role of hpr in the regulation of cry4a protoxin synthesis in bacillus thuringiensis subsp. israelensis, we produced a catabolite repression-negative mutant by replacing the wild-type copy of the ptsh ... | 2002 | 12218029 |
| bioinformatic methods for allergenicity assessment using a comprehensive allergen database. | a principal aim of the safety assessment of genetically modified crops is to prevent the introduction of known or clinically cross-reactive allergens. current bioinformatic tools and a database of allergens and gliadins were tested for the ability to identify potential allergens by analyzing 6 bacillus thuringiensis insecticidal proteins, 3 common non-allergenic food proteins and 50 randomly selected corn (zea mays) proteins. | 2002 | 12218366 |
| [effects of transgenic crops on soil ecosystem]. | the effects of transgenic crops on the soil ecosystem were reviewed. the activity of cry i ab gene and proteinase inhibitor gene in the soil was summarized. the differences of soil microbes' components, soil enzyme activities, and soil fauna between genetic crops and isogenic strain crops were analyzed. according to current progress, the potential impacts of transgenic plant on soil microorganisms depend on the characteristics of the gene transferred into the crops and the soil properties. the c ... | 2002 | 12222061 |
| insect control and dosage effects in transgenic canola containing a synthetic bacillus thuringiensis cryiac gene. | zygotic hypocotyls of canola (brassica napus l.) cv oscar, cv westar, and the breeding line uga188-20b were transformed with a truncated synthetic bacillus thuringiensis insecticidal crystal protein gene (bt cryiac) under the control of the cauliflower mosaic virus 35s promoter using agrobacterium tumefaciens-mediated transformation. fifty-seven independently transformed lines were produced, containing 1 to 12 copies of the transgenes. a range of cry expressors was produced from 0 to 0.4% cry as ... | 1996 | 12226379 |
| contribution of membrane-damaging toxins to bacillus endophthalmitis pathogenesis. | membrane-damaging toxins are thought to be responsible for the explosive clinical course of bacillus endophthalmitis. this study analyzed the contribution of phosphatidylinositol-specific phospholipase c (pi-plc) and phosphatidylcholine-specific phospholipase c (pc-plc) to the pathogenesis of experimental bacillus endophthalmitis. isogenic mutants were constructed by insertion of lacz into bacillus thuringiensis genes encoding pi-plc (plca) and pc-plc (plcb). rabbit eyes were injected intravitre ... | 2002 | 12228262 |
| 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 |
| cloning and expression of cyt2ba7 gene from a soil-isolated bacillus thuringiensis. | bacillus thuringiensis ( bt) cyt genes coding hemolytic and cytolytic toxins constitute a gene family, which are divided into two groups: cyt1 and cyt2. a novel cyt2 gene was detected from a soil-isolated bt strain t301, which was highly homologous to cyt2ba1 and finally designated cyt2ba7. until now, cyt2ba has not been expressed alone in bt or other hosts. in this study, the cyt2ba7 gene was cloned into the vector pqe30 and expressed as a fusion protein with 6xhistidine residues in escherichia ... | 2002 | 12232659 |
| toxicity of bacillus thuringiensis insecticidal proteins for helicoverpa armigera and helicoverpa punctigera (lepidoptera: noctuidae), major pests of cotton. | the susceptibilities of the major pests of cotton in australia, helicoverpa armigera and helicoverpa punctigera, to some insecticidal proteins from bacillus thuringiensis were tested by bioassay. a commercial formulation, dipel, and individual purified insecticidal proteins were tested. h. armigera was consistently more tolerant to b. thuringiensis insecticidal proteins than was h. punctigera, although both were susceptible to only a limited range of these proteins. only cry1ab, cry1ac, cry2aa, ... | 2002 | 12234543 |
| measures of bacillus thuringiensis persistence in the corn whorl. | 2002 | 12234545 | |
| distinct clpp genes control specific adaptive responses in bacillus thuringiensis. | clpp and clpc are subunits of the clp atp-dependent protease, which is ubiquitous among prokaryotic and eukaryotic organisms. the role of these proteins in stress tolerance, stationary-phase adaptive responses, and virulence in many bacterial species has been demonstrated. based on the amino acid sequences of the bacillus subtilis clpc and clpp genes, we identified one clpc gene and two clpp genes (designated clpp1 and clpp2) in bacillus thuringiensis. predicted proteins clpp1 and clpp2 have app ... | 2002 | 12270812 |
| malaria control in a nutshell: palmira ventosilla. | palmira ventosilla, a 35-year old peruvian microbiologist, and her team of researchers at the alexander von humboldt tropical medicine institute in lima, with funding from idrc, have developed a method of controlling malaria through biological control of mosquito larvae. bacillus thuringiensis var. israelensis h-14 (bti) is a naturally occurring bacterium that kills the larvae of anopheles; it is harmless to humans, but expensive to buy from commercial dealers. the team discovered an inexpensi ... | 1995 | 12288548 |
| chromosome aberration assays for the study of cyclophosphamide and bacillus thuringiensis in oxya chinensis (orthoptera: acrididae). | chromosome aberrations induced by an anti-neoplastic drug, cyclophosphamide (cp) and a bioinsecticide, bacillus thuringiensis (b.t.) were examined using grasshoppers as an animal model, with injection as the route of exposure. oxya chinensis (thunberg), having a small number (2n male symbol =23) of large-sized chromosomes in males, was used for this purpose. the fifth instar nymphs were treated with various concentrations of cp (2, 5 and 10 mg/ml) and b.t. (0.55, 1.83 and 5.50 iu/ml) by injectio ... | 2002 | 12297154 |
| does a polyphagous caterpillar have the same gut microbiota when feeding on different species of food plants? | we used classical culture techniques to explore gut bacteria and changes associated with dietary change in the highly polyphagous, tropical caterpillar automeris zugana (saturniidae). fifty-five third instar wild-caught sibs feeding on annona purpurea (annonaceae) in the area de conservación guanacaste (acg) in northwestern costa rica were divided into eight groups. each of seven groups was reared to the ultimate instar on another species of food plant normally used by a. zugana. some pupae were ... | 2002 | 12298285 |
| bacillus thuringiensis in fecal samples from greenhouse workers after exposure to b. thuringiensis-based pesticides. | in a study of occupational exposure to bacillus thuringiensis, 20 exposed greenhouse workers were examined for bacillus cereus-like bacteria in fecal samples and on biomonitoring filters. bacteria with the following characteristics were isolated from eight individuals: intracellular crystalline inclusions characteristic of b. thuringiensis, genes for and production of b. cereus enterotoxins, and positivity for cry11 as determined by pcr. dna fingerprints of the fecal isolates were identical to t ... | 2002 | 12324337 |
| complete sequence and organization of pbtoxis, the toxin-coding plasmid of bacillus thuringiensis subsp. israelensis. | the entire 127,923-bp sequence of the toxin-encoding plasmid pbtoxis from bacillus thuringiensis subsp. israelensis is presented and analyzed. in addition to the four known cry and two known cyt toxins, a third cyt-type sequence was found with an additional c-terminal domain previously unseen in such proteins. many plasmid-encoded genes could be involved in several functions other than toxin production. the most striking of these are several genes potentially affecting host sporulation and germi ... | 2002 | 12324359 |
| the identification of a tetracycline resistance gene tet(m), on a tn916-like transposon, in the bacillus cereus group. | in order to investigate whether resistance genes present in bacteria in manure could transfer to indigenous soil bacteria, resistant isolates belonging to the bacillus cereus group (bacillus cereus, bacillus anthracis and bacillus thuringiensis) were isolated from farm soil (72 isolates) and manure (12 isolates) samples. these isolates were screened for tetracycline resistance genes (tet(k), tet(l), tet(m), tet(o), tet(s) and tet(t)). of 88 isolates examined, three (3.4%) isolates carried both t ... | 2002 | 12351239 |
| slight influence of the estrous cycle stage on the mucosal and systemic specific antibody response induced after vaginal and intraperitoneal immunization with protoxin cry1ac from bacillus thuringiensis in mice. | since the immune response appears to be variable according to the hormonal stage of the mammalian female, the aim of this study was to determine whether estrous cycle stage modifies the mucosal and systemic immune responses induced by intraperitoneal and vaginal immunization of mice with protoxin cry1ac. we tested the influence of three immunizations on the specific antibody response elicited at estrus and diestrus, that were the same estrous cycle stages at which the antigen was applied. both i ... | 2002 | 12354585 |
| cloning and expression of the vegetative insecticidal protein (vip3v) gene of bacillus thuringiensis in escherichia coli. | a genomic library of bacillus thuringiensis var. kurstaki (b.t.k.) was constructed and a positive clone harboring the full-length gene encoding a novel vegetative insecticidal protein (vip3v) was characterized. the vip3v gene was subcloned into pet-22b(+) vector and overexpressed in escherichia coli to an extent of about 30% of the total protein. while transcription was influenced by the t7 promoter of the vector, synthesis of vip3v in e. coli host occurred from the b.t.k. ribosomal binding site ... | 2002 | 12356474 |
| cloning and characterization of an insecticidal crystal protein gene from bacillus thuringiensis subspecies kenyae. | a sporulating culture of bacillus thuringiensis subsp. kenyae strain hd549 is toxic to larvae of lepidopteran insect species such as spodoptera litura, helicoverpa armigera and phthorimaea operculella, and a dipteran insect, culex fatigans. a 1.9-kb dna fragment, pcr-amplified from hd549 using cryii-gene-specific primers, was cloned and expressed in e. coli. the recombinant protein produced 92% mortality in first-instar larvae of spodoptera litura and 86% inhibition of adult emergence in phthori ... | 2002 | 12357073 |
| determination of cry9c protein in processed foods made with starlink corn. | starlink (aventis cropscience us) hybrid corn has been genetically modified to contain a pesticidal protein, cry9c, which makes it more resistant than traditional varieties to certain types of corn insect pests. unlike other varieties of genetically engineered corn, the u.s. environmental protection agency authorized the use of starlink corn for animal feed and industrial use only, not for human consumption. however, some cry9c-containing corn was mistakenly or inadvertently comingled with yello ... | 2002 | 12374406 |
| an abc transporter from bacillus thuringiensis is essential for beta-exotoxin i production. | beta-exotoxin i is a nonspecific insecticidal metabolite secreted by some bacillus thuringiensis strains. several studies of b. thuringiensis strains that have lost the capacity to produce beta-exotoxin i have suggested that there is a strong correlation between high levels of beta-exotoxin i production and the ability to synthesize crystal proteins. in this study, we showed that a mutant strain, b. thuringiensis 407-1(cry(-))(pig(+)), with no crystal gene, produced considerable amounts of beta- ... | 2002 | 12374817 |
| silencing of midgut aminopeptidase n of spodoptera litura by double-stranded rna establishes its role as bacillus thuringiensis toxin receptor. | insecticidal crystal proteins of bacillus thuringiensis bind to receptors in the midgut of susceptible insects leading to pore formation and death of the insect. the identity of the receptor is not clearly established. recently a direct interaction between a cloned and heterologously expressed aminopeptidase (slapn) from spodoptera litura and the cry1c protein was demonstrated by immunofluorescence and in vitro ligand blot interaction. here we show that administration of slapn double-stranded rn ... | 2002 | 12377776 |
| screening bacillus thuringiensis delta-endotoxins for activity against the bertha armyworm, mamestra configurata (lepidoptera: noctuidae). | 2002 | 12384086 | |
| superweed study falters as seed firms deny access to transgene. | 2002 | 12384660 | |
| [anther culture generated stem borer-resistance dh lines of minghui 81(oryza sativa l. subsp. indica) expressing modified cry1ac gene]. | 2600 anthers from t0 modified cry1 ac-transgenic rice lines of minghui 81, an elite restoring line of commercial cms indica hybrid rice, were cultured on sk3 media. 83 green plantlets were recovered, 43 double haploid (dh) and 40 haploid among them. results of pcr analyzes indicated that 55 plants of 83 were harbored the cry1ac gene, and the ratio of cry1ac-positive against cry1ac-negative was 2:1 (55/28). 36 putative transgenic dh plants were further confirmed by southern blot. elisa detection ... | 2002 | 12385240 |
| investigations on genetically modified maize (bt-maize) in pig nutrition: chemical composition and nutritional evaluation. | the objective of the present study was to determine the composition and the nutritional value of parental and transgenic maize seeds fed to pigs. the parental maize line was genetically modified to incorporate a gene from bacillus thuringiensis (bt) expressing a toxin against the european corn borer (ostrinia nubilalis). both (parental and transgenic) maize lines were analyzed for crude nutrients, starch, sugar, non-starch polysaccharides (nsp), amino acids, fatty acids, as well as for selected ... | 2002 | 12389219 |
| [features of the kinetics of accumulating entomocidal exotoxins of bacillus thuringiensis subsp. thuringiensis during fermentation stage of bitoxibacillin production]. | accumulation of bacillus thuringiensis subsp. thuringiensis beta-exotoxin (bet) in the course of industrial fermentation (a stage in the production of the entomocidal biopreparation bitoxibacillin) has been studied. it has been demonstrated in model experiments that the decrease in the content of bet in the culture fluid is accounted for by the toxin interaction with an attendant product, the exogenous metabolite (em). em has been isolated from the culture fluid and characterized. em causes alka ... | 2002 | 12391756 |
| [induced phytophthora resistance in transgenic potato tubers]. | resistance of transgenic cultivars based on the expression of one or more resistance genes is sooner or later broken by pathogens whose race-producing rates are high. thus, combining transgenesis with elicitor-induced resistance is a promising approach. the elicitor-induced resistance is based on the expression of multiple resistance genes, which can prevent the adaptation of pathogens to transgenic races, maintain the stability of cultivars, and increase their lifespan. in this work, we used tr ... | 2002 | 12391758 |
| isolation and characterization of a novel bacillus strain from coffee phyllosphere showing antifungal activity. | the isolation and characterization of a novel coffee-associated bacillus mojavensis strain, designated as strain ab1, and its survival on the coffee phyllosphere. | 2002 | 12392522 |
| interaction between cry9ca and two cry1a delta-endotoxins from bacillus thuringiensis in larval toxicity and binding to brush border membrane vesicles of the spruce budworm, choristoneura fumiferana clemens. | a genetically altered variant of cry9ca from bacillus thuringiensis shows high potency against the spruce budworm, choristoneura fumiferana clemens. its activity, as measured by feeding inhibition in frass-failure assays, is estimated to be four to seven times greater than b. thuringiensis subsp. kurstaki hd-1, the strain currently used in commercial products to control this insect. bioassays against budworm of mixtures of the modified cry9ca and two of the cry1a endotoxin proteins produced by h ... | 2002 | 12393209 |
| phenotypic and genetic diversity of bacillus thuringiensis strains isolated in india active against spodoptera litura. | bacillus thuringiensis strains isolated from different agroclimatic regions of india were found to harbor cry1 family genes. of 831 strains 18 that were found to produce 130- and 68-kda mol wt proteins in sodium dodecyl sulfate polyacry1amide gel electrophoresis were subjected to bioassay against second instar larvae of spodoptera litura. according to the time response curve, while the highest toxic activity against s. litura was observed in pbt-782 with an lt50 of 25.46 h, strains pbt-372, pbt- ... | 2002 | 12396125 |
| sequencing of 16s rrna gene: a rapid tool for identification of bacillus anthracis. | in a bioterrorism event, a tool is needed to rapidly differentiate bacillus anthracis from other closely related spore-forming bacillus species. during the recent outbreak of bioterrorism-associated anthrax, we sequenced the 16s rrna generom these species to evaluate the potential of 16s rrna gene sequencing as a diagnostic tool. we found eight distinct 16s types among all 107 16s rrna gene seqs fuences that differed from each other at 1 to 8 positions (0.06% to 0.5%). all 86 b. anthracis had an ... | 2002 | 12396926 |
| susceptibility of field-collected populations of the southwestern corn borer, diatraea grandiosella, to bacillus thuringiensis. | the susceptibilitity of newly hatched larvae of laboratory-adapted and field-collected populations of the southwestern corn borer, diatraea grandiosella (dyar) (lepidoptera: crambidae), to a bacillus thuringiensis protein (cry1ab) was examined using a larval feeding bioassay. d grandiosella populations were collected from five states: missouri, kansas, texas, tennessee and kentucky. using larval mortality as the end-point of the bioassay, the magnitude of differences in the susceptibility of the ... | 2002 | 12400441 |
| intracellular proteases of bacillus thuringiensis subsp. kurstaki and a protease-deficient mutant btk-q. | the commencement of intracellular protease synthesis was studied by gelatin zymography in bacillus thuringiensis ( btk) hd1, btk hd73, and a protease-deficient mutant btk-q derived from the former strain. by gelatin zymography, a 92-kda protease was detected first at 3 h of sporulation, which continued until 48 h, whereas two other proteases of mol wt 78 and 69 kda were detectable from 6 h onwards and continued until 48 h of growth in btk hd1. similar studies revealed the presence of two major i ... | 2002 | 12402080 |
| biotechnology and the european corn borer: measuring historical farmer perceptions and adoption of transgenic bt corn as a pest management strategy. | a 3-yr, multi-state survey of farmers who had planted transgenic bacillus thuringiensis (bt) corn was conducted to evaluate perceptions of bt corn performance and its utility as a management option for european corn borer, ostrinia nubilalis (hübner). a questionnaire was sent to farmers in illinois, iowa, kansas, minnesota, nebraska, and pennsylvania who had grown bt corn during the growing seasons of 1996, 1997, or 1998. there were 7,427 usable questionnaires returned with the following respons ... | 2002 | 12403412 |
| use of mathematical models to estimate characteristics of pyrethroid resistance in tobacco budworm and bollworm (lepidoptera: noctuidae) field populations. | genetic models have been used to examine the evolution of insecticide resistance in pest species subject to data and assumptions regarding genetic, biological, and operational parameters. we used time-series data on pyrethroid tolerance and simple genetic models to estimate underlying genetic and biological parameters associated with resistance evolution in tobacco budworm, heliothis virescens (f.), and bollworm, helicoverpa zea (boddie), louisiana field populations. assuming pyrethroid resistan ... | 2002 | 12403428 |
| inheritance of resistance to bt toxin crylac in a field-derived strain of pink bollworm (lepidoptera: gelechiidae). | laboratory selection with cry1ac, the bacillus thuringiensis (bt) toxin in transgenic cotton, initially produced 300-fold resistance in a field-derived strain of pink bollworm, pectinophora gossypiella (saunders), a major cotton pest. after additional selection increased resistance to 3,100-fold, we tested the offspring of various crosses to determine the mode of inheritance of resistance to cry1ac. the progeny of reciprocal f1 crosses (resistant male x susceptible female and vice versa) respond ... | 2002 | 12403429 |
| modeling the development of resistance by stalk-boring lepidopteran insects (crambidae) in areas with transgenic corn and frequent insecticide use. | we simulated the population dynamics and population genetics of two bivoltine species of corn borers, the european corn borer, ostrinia nubilalis (hübner), and the southwestern corn borer, diatraea grandiosella dyar, in a hypothetical region of irrigated transgenic and nontransgenic corn where insecticide was applied only to the nontransgenic refuge crop. over the 100-yr time horizon, resistance developed quickly in both species and to both transgenic corn and the insecticide when the allele for ... | 2002 | 12403431 |
| cytotoxic activity of bacillus thuringiensis cry proteins on mammalian cells transfected with cadherin-like cry receptor gene of bombyx mori (silkworm). | cry1aa, an insecticidal protein produced by bacillus thuringiensis, has been shown to bind to cadherin-like protein, btr175, in bombyx mori (silkworm) midgut. we previously reported three variant alleles of btr175 (btr175a, b and c). when transiently expressed in cos7 cells, all the three btr175 variants bound to cry1aa. we stably expressed btr175b in hek293 cells. these btr175b-expressing cells swelled and died in the presence of activated cry1aa in a dose- and time-dependent manner, showing th ... | 2003 | 12403648 |
| efficiency of mannose-binding plant lectins in controlling a homopteran insect, the red cotton bug. | yield losses of different crops due to the attack of various classes of insects are a worldwide problem. sucking type homopteran pests causing damage to many crop species are not controlled by commonly known insecticidal proteins, namely, bacillus thuringiensis delta-endotoxin (bt). this study describes the purification of mannose-binding lectins from three different monocotyledonous plants (allium sativum, colocasia esculenta, and diffenbachia sequina) and their effects on a homopteran insect, ... | 2002 | 12405774 |
| altered glycosylation of 63- and 68-kilodalton microvillar proteins in heliothis virescens correlates with reduced cry1 toxin binding, decreased pore formation, and increased resistance to bacillus thuringiensis cry1 toxins. | the binding and pore formation abilities of cry1a and cry1fa bacillus thuringiensis toxins were analyzed by using brush border membrane vesicles (bbmv) prepared from sensitive (ydk) and resistant (yhd2) strains of heliothis virescens. 125i-labeled cry1aa, cry1ab, and cry1ac toxins did not bind to bbmv from the resistant yhd2 strain, while specific binding to sensitive ydk vesicles was observed. binding assays revealed a reduction in cry1fa binding to bbmv from resistant larvae compared to cry1fa ... | 2002 | 12406769 |
| esterases as biomarkers in nereis (hediste) diversicolor exposed to temephos and bacillus thuringiensis var. israelensis used for mosquito control in coastal wetlands of morbihan (brittany, france). | since 1998, a biomonitoring programme has been implemented to assess the potential impact of chemical mosquito control on macroinvertebrates of the coastal wetlands of morbihan (brittany, france). acetylcholinesterase and carboxylesterases were used as biomarkers to assess the effects of abate 500e (a.i. temephos) and vectobac 12 as (a.i. endotoxins of bacillus thuringiensis var. israelensis, bti) in nereis (hediste) diversicolor. esterase inhibition revealed a marked impact of temephos, suggest ... | 2002 | 12408646 |
| discrepancy between cry gene-predicted and bioassay-determined insecticidal activities in bacillus thuringiensis natural isolates. | 2002 | 12417216 | |
| plant toxic proteins with insecticidal properties. a review on their potentialities as bioinsecticides. | to meet the demands for food of the expanding world population, there is need of new ways for protecting plant crops against predators and pathogens while avoiding the use of environmentally aggressive chemicals. a milestone in this field was the introduction into crop plants of genes expressing bacillus thuringiensis entomotoxic proteins. in spite of the success of this new technology, however, there are difficulties for acceptance of these 'anti-natural' products by the consumers and some conc ... | 2002 | 12419503 |
| transgenic drosophila reveals a functional in vivo receptor for the bacillus thuringiensis toxin cry1ac1. | the bacterium bacillus thuringiensis synthesizes toxins (delta-endotoxins) that are highly specific for insects. once ingested, the activated form of the toxin binds to a specific receptor(s) located on the midgut epithelial cells, inserts into the membrane causing the formation of leakage pores and eventual death of the susceptible insect larvae. manduca sexta larvae are highly susceptible to cry1ac1, a toxin that is believed to bind m. sexta aminopeptidase n, a glycoprotein located on the apic ... | 2002 | 12421420 |
| research needs to improve agricultural productivity and food quality, with emphasis on biotechnology. | research into agricultural productivity, especially for crops in the developing world, should include resistance to plant viruses, fungi and the parasitic weed striga. it must also include research into the development of resistance to bacillus thuringiensis (bt) toxin-expressing crops. drought- and heat-tolerant crops, and those that can combat the problems of soil deficiencies, are required, and vaccine production in plants should be a high priority. research into food quality should include t ... | 2002 | 12421866 |
| food aid. zambia rejects gm corn on scientists' advice. | 2002 | 12424345 | |
| 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 |
| requirement of flha for swarming differentiation, flagellin export, and secretion of virulence-associated proteins in bacillus thuringiensis. | bacillus thuringiensis is being used worldwide as a biopesticide, although increasing evidence suggests that it is emerging as an opportunistic human pathogen. while phospholipases, hemolysins, and enterotoxins are claimed to be responsible for b. thuringiensis virulence, there is no direct evidence to indicate that the flagellum-driven motility plays a role in parasite-host interactions. this report describes the characterization of a mini-tn10 mutant of b. thuringiensis that is defective in fl ... | 2002 | 12426328 |
| proteolytic cleavage of the developmentally important cadherin bt-r1 in the midgut epithelium of manduca sexta. | bt-r1 (m(r) = 210 kda) represents a new type of insect cadherin that is expressed specifically in the midgut epithelium during growth and development of manduca sexta larvae. it also is a target receptor for the cry1a toxins of the entomopathogenic bacterium bacillus thuringiensis. expression of bt-r1, which varies during larval development, correlates with the abundance of the protein and with the differential cleavage of the molecule at each developmental stage. the cleavage of bt-r1 is calciu ... | 2002 | 12427034 |
| rapid degradation of the cry1f insecticidal crystal protein in soil. | the gene for the core cry1f insecticidal crystal protein (icp) from bacillus thuringiensis berliner (bt) has been incorporated into the genome of maize plants, zea mays l. plants expressing this icp are protected from attack by various lepidopteran pests including the european corn borer, ostrinia nubilalis (hübner). the stability of the cry1f icp in soil was assessed in a laboratory study designed to determine the persistence of the active protein residue in soil over time, using insect bioassa ... | 2002 | 12428962 |
| cloning and characterization of two novel crystal protein genes from a bacillus thuringiensis serovar dakota strain. | two genes encoding the 32- and 40-kda polypeptides of bacillus thuringiensis strain 90-f-45-14 crystals were cloned, expressed in an acrystalliferous b. thuringiensis strain, and sequenced. the polypeptides had deduced molecular weights of 30,319 and 33,885, respectively. the amino acid sequence of the 32-kda protein was 37.7% identical to the known sequence of a non-insecticidal parasporal protein in b. thuringiensis serovar thompsoni crystals. the sequence of the cloned 40-kda protein was 37.0 ... | 2003 | 12432461 |
| mannose-specific lectin activity of parasporal proteins from a lepidoptera-specific bacillus thuringiensis strain. | lectin activity, agglutinating sheep erythrocytes, was associated with parasporal inclusion proteins from a lepidoptera-specific isolate of bacillus thuringiensis serovar galleriae (h5ab). the activity was generated when parasporal inclusions were solubilized in an alkaline condition. proteolytic processing was not required for generation of the lectin activity; the activity level was not affected by the presence/absence of the three proteases (trypsin, chymotrypsin, and proteinase k). sds-page ... | 2003 | 12432463 |
| determination of poly-beta-hydroxybutyric acid in bacillus thuringiensis by capillary zone electrophoresis with indirect ultraviolet absorbance detection. | a new capillary electrophoresis method for determining poly-beta-hydroxybutyric acid (phb) in bacillus thuringiensis was established. poly-beta-hydroxybutyric acid in samples was hydrolyzed by sulphuric acid and neutralized by ba(oh)2. the content of produced beta-hydroxybutyrate was then determined by capillary zone electrophoresis (cze) with indirect uv detection at 254 nm. with 5 mm p-hydroxybenzoate and 0.5 mm tetradecyltrimethylammonium bromide (ttab) at ph 8.0 as carrier electrolyte, beta- ... | 2002 | 12437178 |
| search for potential vaccine candidate open reading frames in the bacillus anthracis virulence plasmid pxo1: in silico and in vitro screening. | a genomic analysis of the bacillus anthracis virulence plasmid pxo1, aimed at identifying potential vaccine candidates and virulence-related genes, was carried out. the 143 previously defined open reading frames (orfs) (r. t. okinaka, k. cloud, o. hampton, a. r. hoffmaster, k. k. hill, p. keim, t. m. koehler, g. lamke, s. kumano, j. mahillon, d. manter, y. martinez, d. ricke, r. svensson, and p. j. jackson, j. bacteriol. 181:6509-6515, 1999) were subjected to extensive sequence similarity search ... | 2002 | 12438358 |
| recombinantly expressed isoenzymic aminopeptidases from helicoverpa armigera (american cotton bollworm) midgut display differential interaction with closely related bacillus thuringiensis insecticidal proteins. | several investigators have independently identified membrane-associated aminopeptidases in the midgut of insect larvae as the initial interacting ligand to the insecticidal crystal proteins of bacillus thuringiensis. though several isoenzymes of aminopeptidases have been identified from the midgut of an insect and their corresponding cdna cloned, only one of the isoform has been expressed heterologously and studied for its binding to cry toxins. here we report the cloning and expression of two a ... | 2003 | 12441000 |
| antitrichomonal strains of bacillus thuringiensis. | parasporal inclusion proteins from a total of 816 bacillus thuringiensis strains isolated in japan were examined for antitrichomonal activity against trichomonas vaginalis. ten strains of b. thuringiensis inhibited the growth of t. vaginalis in 48 h cultures at 37 degrees c. moreover, the b622 and b626 strains clearly showed trichomonacidal effects against t. vaginalis. the h antigen serotypes of both strains were identified as h13/29 (pakistani/amagiensis). the parasporal inclusion protein from ... | 2002 | 12444461 |
| assessment of the efficacy of japanese bacillus thuringiensis isolates against the cigarette beetle, lasioderma serricorne (coleoptera: anobiidae). | a total of 2,652 japanese isolates of bacillus thuringiensis, belonging to at least 54 h serogroups, were examined for assessment of the toxicity against the cigarette beetle, lasioderma serricorne (coleoptera: anobiidae). when tested with spore/parasporal inclusion mixtures, strong larvicidal activities were associated with 28 isolates (1.1%). serologically, these toxic isolates fell into 4 known h serovars: thuringiensis (9 isolates), kurstaki (2), kenyae (2), and darmstadiensis (15). purified ... | 2002 | 12445796 |
| studies on the production of b. thuringiensis based biopesticides using wastewater sludge as a raw material. | growth and delta-endotoxin yield of bacillus thuringiensis (bt) subsp kurstaki in tryptic soy yeast extract (tsy) medium, soybean meal based commercial medium and wastewater sludge medium were studied. the viable spores (vs) count in sludge medium was comparable to that obtained in laboratory and commercial media. the entomotoxicity of the fermentation liquid (bt grown sludge) against choristoneura fumiferana was comparable to the concentrated commercial bt formulation available in the market (f ... | 2002 | 12448528 |
| natural occurrence of bacillus thuringiensis on cabbage foliage and in insects associated with cabbage crops. | bacillus thuringiensis was isolated from the phylloplane of organically grown cabbage in one field during two growth seasons (1992-93). the frequency of b. thuringiensis varied between 0.02 and 0.67 of the total b. cereus/b. thuringiensis population, with an average of 0.11. characterization of the b. thuringiensis isolates from foliage showed that the majority (64% of 150 isolates) belonged to serovar kurstaki, had bipyramidal crystals and toxicity towards pieris brassicae and/or trichoplusia n ... | 1997 | 12452602 |
| heterologous expression of cry2 gene from a local strain of bacillus thuringiensis isolated in nigeria. | a cry2 gene encoding a larvicidal crystal protein was isolated from a strain of bacillus thuringiensis found in soil samples in nigeria. this gene was cloned into plasmid puc19 and subcloned into both pbluescript (sk(+/-)) and ppicz alpha b placed under a t7/aoxi (alcohol oxidase i) promoter respectively and transformed into escherichia coli and pichia pastoris. clones were induced for expression, and the cellular proteins extracted and analysed by sds/page. integration of an insert into the yea ... | 2002 | 12452809 |
| a single phylogenetic analysis of bacillus thuringiensis strains and bacilli species inferred from 16s rrna gene restriction fragment length polymorphism is congruent with two independent phylogenetic analyses. | to assess the congruence between two earlier independent phylogenetic studies on bacillus thuringiensis strains and on bacillus-related species and the single, all-encompassing, phylogenetic tree presented here inferred from the combination of the two earlier datasets. | 2002 | 12452965 |
| regulation of crystal protein biosynthesis by bacillus thuringiensis: i. effects of mineral elements and ph. | crystal protein synthesis by a local isolate of bacillus thuringiensis was monitored and compared in association with growth and sporulation in media differing in mineral element content. mg and cu were the most important metals for the biosynthesis of 135 kda and 65 kda toxin components in that the former was essential and the latter was greatly stimulatory at 10(-6) to 10(-7) m concentration. also the inclusion of mn favored toxin production at concentrations ranging from 3 x 10(-4) to 10(-5) ... | 2002 | 12455708 |
| regulation of crystal protein biosynthesis by bacillus thuringiensis: ii. effects of carbon and nitrogen sources. | the regulation of crystal protein production in bacillus thuringiensis 81 by sources of carbon and nitrogen was investigated. the highest titers of toxin were obtained on sucrose, lactose and inulin which also supported sporulation. whey and molasses were also potential carbon substrates for toxin production. other carbohydrates including glucose, glycerol, maltose, starch and dextrin yielded lower amounts of toxin. nitrogen sources were found to exert the most profound controls. peptone was the ... | 2002 | 12455709 |
| bacillus thuringiensis-toxin resistance management: stable isotope assessment of alternate host use by helicoverpazea. | data have been lacking on the proportion of helicovera zea larvae that develop on noncotton host plants that can serve as a refuge from selection pressure for adaptation to transgenic cotton varieties that produce a toxin from the bacterium bacillus thuringiensis. we found that individual h. zea moths that develop as larvae on cotton and other plants with c3 physiology have a different ratio of 13c to 12c than moths that develop on plants with c4 physiology, such as corn. we used this finding in ... | 2002 | 12464681 |