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functional screening of metagenome and genome libraries for detection of novel flavonoid-modifying enzymes.the functional detection of novel enzymes other than hydrolases from metagenomes is limited since only a very few reliable screening procedures are available that allow the rapid screening of large clone libraries. for the discovery of flavonoid-modifying enzymes in genome and metagenome clone libraries, we have developed a new screening system based on high-performance thin-layer chromatography (hptlc). this metagenome extract thin-layer chromatography analysis (meta) allows the rapid detection ...201323686272
decontamination of materials contaminated with bacillus anthracis and bacillus thuringiensis al hakam spores using pes-solid, a solid source of peracetic acid.to develop test methods and evaluate survival of bacillus anthracis ames, b. anthracis ∆sterne and b. thuringiensis al hakam spores after exposure to pes-solid (a solid source of peracetic acid), including pes-solid formulations with bacteriostatic surfactants.201323692445
digestive enzyme as benchmark for insecticide resistance development in culex pipiens larvae to chemical and bacteriologic insecticides.this work monitored changes in some digestive enzymes (trypsin and aminopeptidase) associated with the building up of resistance in cx. pipiens larvae to two chemical insecticides (methomyl and/or malathion) and one biological insecticide (bacillus thuringiensis-h14 or b.t h 14). the lc50 value of methomyl for both field- and the 12th generation (f12) of the selected strain was 1.789 ppm and 8.925 ppm respectively. the lc50 value of malathion for both field and the f12 of the selected strain was ...201323697030
sustainable control of mosquito larvae in the field by the combined actions of the biological insecticide bti and natural competitors.integrated management of mosquitoes is becoming increasingly important, particularly in relation to avoiding recolonization of ponds after larvicide treatment. we conducted for the first time field experiments that involved exposing natural populations of the mosquito species culex pipiens to: a) application of the biological insecticide bacillus thuringiensis israelensis (bti), b) the introduction of natural competitors (a crustacean community composed mainly of daphnia spp.), or c) a combined ...201323701611
use of a pooled clone method to isolate a novel bacillus thuringiensis cry2a toxin with activity against ostrinia furnacalis.a pooled clone method was developed to screen for cry2a genes. this metagenomic method avoids the need to analyse isolated bacillus thuringiensis strains by performing gene specific pcr on plasmid-enriched dna prepared from a pooled soil sample. using this approach the novel holotype gene cry2ah1 was cloned and characterized. the toxin gene was over-expressed in escherichia coli rosetta (de3) and the expressed toxin accumulated in both the soluble and insoluble fractions. the soluble cry2ah1 was ...201323711413
mega-nano detection of foodborne pathogens and transgenes using molecular beacon and semiconductor quantum dot technologies.signature molecules derived from listeria monocytogenes, bacillus thuringiensis, and salmonella typhimurium were detected directly on food substrates (mega) by coupling molecular beacon technology utilizing fluorescent resonance energy transfer (fret), luminescent nanoscale semiconductor quantum dots, and nanoscale quenchers. we designed target dna sequences for detecting hlya, bt cry1ac, and inva genes from l. monocytogenes, b. thuringiensis and salmonella typhimurium, respectively, and prepare ...201323722479
characterization of three antifungal calcite-forming bacteria, arthrobacter nicotianae knuc2100, bacillus thuringiensis knuc2103, and stenotrophomonas maltophilia knuc2106, derived from the korean islands, dokdo and their application on mortar.crack remediation on the surface of cement mortar using microbiological calcium carbonate (caco3) precipitation (micp) has been investigated as a microbial sealing agent on construction materials. however, micp research has never acknowledged the antifungal properties of calcite-forming bacteria (cfb). since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. therefore, to develop a microbial sealing agent that has an ...201323727794
intermolecular interaction between cry2aa and cyt1aa and its effect on larvicidal activity against culex quinquefasciatus.the cyt1aa protein of bacillus thuringiensis susbp. israelensis elaborates demonstrable toxicity to mosquito larvae, but more importantly, it enhances the larvicidal activity of this species cry proteins (cry11aa, cry4aa, and cry4ba) and delays the phenotypic expression of resistance to these that has evolved in culex quinquefasciatus. it is also known that cyt1aa, which is highly lipophilic, synergizes cry11aa by functioning as a surrogate membrane-bound receptor for the latter protein. little ...201323727800
efficiency and midgut histopathological effect of the newly isolated bacillus thuringiensis ks δ-endotoxins on the emergent pest tuta absoluta.tuta absoluta (povolny, 1994) is a devastating moth to the solanaceae plants. it is a challenging pest to control, especially on tomatoes. in this work, we studied the entomopathogenic activity of the cry-forming δ-endotoxins produced by bacillus thuringiensis strain ks and b. thuringiensis kurstaki reference strain hd1 against t. absoluta. these strains carried the cry2, cry1ab, cry1aa / cry1ac, and cry1i genes, and ks also carried a cry1c gene. the δ-endotoxins of ks were approximately twofold ...201323727813
molecular characterization of chitinase genes from a local isolate of serratia marcescens and their contribution to the insecticidal activity of bacillus thuringiensis strains.the chitinase b (chib) and c (chic) genes and flanking regions from a local isolate of serratia marcescens were cloned individually and sequenced. results showed that these chib and chic genes have a 96 % maximum similarity with chib and chic from different s. marcescens species (genbank numbers z36295.1 and aj630582.1, respectively). the amplified chib fragment, including some upstream and downstream regions, is 1,689-bp long with an open reading frame of 1,500 bp. the amplified fragment of chi ...201323728785
computational modeling deduced three dimensional structure of cry1ab16 toxin from bacillus thuringiensis ac11.the first theoretical structural model of newly reported cry1ab16 δ-endotoxin produced by bacillus thuringiensis ac11 was predicted using homology modeling technique. cry1ab16 resembles the cry1aa protein structure by sharing a common three domains structure responsible in pore forming and specificity determination along with few structural deviations. the main differences between the two is in the length of loops, absence of α7b, α9a, α10b, α11a and presence of additional β12b, α13 components w ...201123729892
developmental regulation and antifungal activity of a growth-blocking peptide from the beet armyworm spodoptera exigua.insect cytokine growth-blocking peptides (gbps) are involved in growth regulation and the innate immune response. however, the microbial binding and antimicrobial activities of gbps remain unclear. here, we investigate the developmental role and antifungal activity of a gbp from the beet armyworm spodoptera exigua (segbp). sequence analysis predicted that mature segbp consists of 24 amino acid residues, including 2 cysteine residues. during s. exigua development, segbp is constitutively expresse ...201323732405
optimization of photobioreactor growth conditions for a cyanobacterium expressing mosquitocidal bacillus thuringiensis cry proteins.an anabaena strain (pcc 7120#11) that was genetically engineered to express bacillus thuringiensis subsp. israelensis cry genes has shown good larvicidal activity against anopheles arabiensis, a major vector of malaria in africa. response surface methodology was used to evaluate the relationship between key growth factors and the volumetric productivity of pcc 7120#11 in an indoor, flat-plate photobioreactor. the interaction of input co₂ concentration and airflow rate had a statistically signifi ...201323732832
the red flour beetle as a model for bacterial oral infections.experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. the red flour beetle tribolium castaneum and the spore-forming bacterial insect pathogen bacillus thuringiensis (bt) are widely used and tractable model organisms. however, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. we used a high throughput oral infection protocol to infect t. castaneum insects with c ...201323737991
characterization of bacillus thuringiensis cry1 class proteins in relation to their insecticidal action.thirty nine bt cry1 subgroup protein sequences were retrieved from ncbi and analyzed for physicochemical properties, active site and relationship in relation to their variations in toxicity. cry1 proteins were found to be hydrophilic and stable. sosui server predicted presence of two transmembrane regions in ag and a single transmembrane region from aa to ae. emboss pepwheel tool analysis of the transmembrane regions showed that there were 23 highly conserved residues towards the n terminal whic ...201323740394
sequence variation and differential splicing of the midgut cadherin gene in trichoplusia ni.the insect midgut cadherin serves as an important receptor for the cry toxins from bacillus thuringiensis (bt). variation of the cadherin in insect populations provides a genetic potential for development of cadherin-based bt resistance in insect populations. sequence analysis of the cadherin from the cabbage looper, trichoplusia ni, together with cadherins from 18 other lepidopterans showed a similar phylogenetic relationship of the cadherins to the phylogeny of lepidoptera. the midgut cadherin ...201323743444
combining hexanoic acid plant priming with bacillus thuringiensis insecticidal activity against colorado potato beetle.interaction between insect herbivores and host plants can be modulated by endogenous and exogenous compounds present in the source of food and might be successfully exploited in colorado potato beetle (cpb) pest management. feeding tests with cpb larvae reared on three solanaceous plants (potato, eggplant and tomato) resulted in variable larval growth rates and differential susceptibility to bacillus thuringiensis cry3aa toxin as a function of the host plant. an inverse correlation with toxicity ...201323743826
response of larval ephestia kuehniella (lepidoptera: pyralidae) to individual bacillus thuringiensis kurstaki toxins mixed with xenorhabdus nematophila.bacillus thuringiensis kurstaki strain bns3 produces parasporal crystals formed by cry1aa, cry1ac and cry2aa delta-endotoxins. in a previous work, we showed that the latter exhibited individually, a weak insecticidal activity against ephestia kuehniella. in order to improve their toxicities, we studied the combined effect of each delta-endotoxin with x. nematophila cells on e. kuehniella larvae growth. xenorhabdus cells were used in combination with spore crystal mixture of the wild strain bns3, ...201323747825
cross-order and cross-phylum activity of bacillus thuringiensis pesticidal proteins.the increasing number of bacillus thuringiensis proteins with pesticidal activities across orders and phyla raises the question how widespread cross-activities are and if they are of sufficient biological significance to have implications for ecological safety of those proteins in pest control applications. cross-activity is reported for 27 proteins and 69 taxa and is substantiated by reasonable evidence (mortality estimates) in 19 cases involving 45 taxa. cross-activities occur in 13 primary ra ...201323747826
enhanced cry1da production in bacillus thuringiensis by driving expression from the σ(e) -dependent bti promoter.to increase the cry1da production in bacillus thuringiensis by enhancing bti promoter activity and fusion with upstream sequence from cry1ab.201323751196
effects of genetically modified t2a-1 rice on the gi health of rats after 90-day supplement.bacillus thuringiensis insecticidal toxin (bt) rice will be commercialized as a main food source. traditional safety assessments on genetically modified products pay little attention on gastrointestinal (gi) health. more data about gi health of bt rice must be provided to dispel public' doubts about the potential effects on human health. we constructed an improved safety assessment animal model using a basic subchronic toxicity experiment, measuring a range of parameters including microflora com ...201323752350
insect resistance to bt crops: lessons from the first billion acres.evolution of resistance in pests can reduce the effectiveness of insecticidal proteins from bacillus thuringiensis (bt) produced by transgenic crops. we analyzed results of 77 studies from five continents reporting field monitoring data for resistance to bt crops, empirical evaluation of factors affecting resistance or both. although most pest populations remained susceptible, reduced efficacy of bt crops caused by field-evolved resistance has been reported now for some populations of 5 of 13 ma ...201323752438
a cadherin-like protein influences bacillus thuringiensis cry1ab toxicity in the oriental armyworm, mythimna separata.cadherins comprise a family of calcium-dependent cell adhesion proteins that act in cell-cell interactions. cadherin-like proteins (cads) in midguts of some insects act as receptors that bind some of the toxins produced by the bacillus thuringiensis (bt). we cloned a cad gene associated with larval midguts prepared from mythimna separata. the full-length cdna (mscad1, genbank accession no. jf951432) is 5642 bp, with an open reading frame encoding a 1757 amino acid and characteristics typical of ...201323754724
the cry4b toxin of bacillus thuringiensis subsp. israelensis kills permethrin-resistant anopheles gambiae, the principal vector of malaria.resurgence of malaria has been attributed, in part, to the development of resistance by anopheles gambiae, a principal vector of the disease, to various insecticidal compounds such as permethrin. permethrin, a neurotoxicant, is widely used to impregnate mosquito nets. an alternative strategy to control mosquitoes is the use of bacillus thuringiensis subsp. israelensis (bti) because there is no observable resistance in the field to the bacterium. bti kills mosquitoes by targeting cadherin molecul ...201323760000
phylogenetic distribution of phenotypic traits in bacillus thuringiensis determined by multilocus sequence analysis.diverse isolates from a world-wide collection of bacillus thuringiensis were classified based on phenotypic profiles resulting from six biochemical tests; production of amylase (t), lecithinase (l), urease (u), acid from sucrose (s) and salicin (a), and the hydrolysis of esculin (e). eighty two isolates representing the 15 most common phenotypic profiles were subjected to phylogenetic analysis by multilocus sequence typing; these were found to be distributed among 19 sequence types, 8 of which w ...201323762464
family portrait of bacillus cereus and bacillus weihenstephanensis cereulide-producing strains.two thousand bacillus cereus sensu lato isolates from food and environmental matrices were screened by pcr for the presence of cereulide-producing strains. this survey identified 73 potential emetic strains, most of which originated from non-random food and clinical samplings. none of the 460 bacillus thuringiensis, bacillus mycoides and bacillus pseudomycoides strains were pcr-positive for the cereulide genetic determinants. the chromosomal and extrachromosomal gene pool diversity of a subset o ...200923765791
cross-generational feeding of bt (bacillus thuringiensis)-maize to zebrafish (danio rerio) showed no adverse effects on the parental or offspring generations.in the present study, zebrafish (danio rerio) were fed casein/gelatin-based diets containing either 19% bt (bacillus thuringiensis)-maize or its parental non-bt (nbt)-maize control for two generations (f0: sixty fish; f1: forty-two to seventy fish per treatment). the study focused on growth and reproductive performance, liver cuzn superoxide dismutase (sod) enzyme activity, gene transcript levels targeting important cellular pathways in the liver and mid-intestine, histomorphological evaluation ...201323768244
potentiating 1-(2-hydroxypropyl)-2-styryl-5-nitroimidazole derivatives against antibacterial agents: design, synthesis and biology analysis.a series of novel 1-(2-hydroxypropyl)-2-styryl-5-nitroimidazole derivatives had been designed, synthesized, isolated and evaluated as potentiators of antibacterial agents. all these synthesized compounds were determined by elemental analysis, (1)h nmr, and ms. their biological activities were also evaluated against two gram-negative bacterial strains: escherichia coli and pseudomonas aeruginosa and two gram-positive bacterial strains: bacillus thuringiensis and bacillus subtilis by mtt method as ...201323770447
potato flour mediated solid-state fermentation for the enhanced production of bacillus thuringiensis-toxin.in this study, we explored the efficacy of raw potato flour (pf) as supplement to the conventional lb medium (lb control, designated as m1) for enhancing the concomitant production of endospores and δ-endotoxin from bacillus thuringiensis subsp. kurstaki by solid-state fermentation (ssf). of different concentrations and combinations of media tested, 10% (w/v) pf supplemented lb medium (m2) was found as the best source for the maximum yield of toxin. after 12 h submerged fermentation (smf) at 37° ...201323773700
bacillus thuringiensis insecticidal crystal proteins affect lifespan and reproductive performance of helicoverpa armigera and spodoptera exigua adults.being delivered as sprays or expressed in plant, bacillus thuringiensis (bt) crystalline proteins (cry toxins) display insecticidal activities against numerous lepidopteran, dipteran, and coleopteran larvae. comparative study of toxicities of bt cry toxins between larvae and adults may afford important new insights into the interactions of the toxins with receptor proteins in host insect, and represent intriguing targets for the control of insect pests. however, the effectiveness of bt cry toxin ...201323786046
injury and interplant compensation for southwestern corn borer (lepidoptera: crambidae) infestations in field corn.growers that plant bacillus thuringiensis (bt) berliner corn (zea mays l.) hybrids are required to plant non-bt corn for resistance management. refuge in a bag (rib) is an emerging approach for resistance management where, for some hybrids having multiple bt traits for a target species, the refuge is planted as a blend of bt and non-bt corn. studies were conducted to evaluate how southwestern corn borer (diatraea grandiosella dyar), when infested at different densities and growth stages, affecte ...201323786069
evaluation of corn hybrids expressing cry34ab1/cry35ab1 and cry3bbl against the western corn rootworm (coleoptera: chrysomelidae).studies were conducted across nine u.s. states, over 5 yr, to characterize the efficacy of transgenic corn (zea mays l.) hybrids producing insecticidal proteins derived from bacillus thuringiensis (bt) for control of western corn rootworm, diabrotica virgifera virgifera le conte. hybrids tested had the same genetic background, contained one of two single events (das-59122-7 expressing cry34ab1/cry35ab1 or mon 88017 expressing cry3bb1) or a pyramid consisting of both rootworm-active events (smart ...201323786070
segregation and efficacy of the cry1ia1 gene for control of potato tuberworm in four populations of cultivated potato.the potato (solanum tuberosum l.) cultivar 'spuntag2' contains a single copy of the bacillus thuringiensis (bt) cry1ia1 gene and controls potato tuberworm (phthorimaea operculella zeller, lepidoptera: gelechiidae). two potato cultivars and two breeding lines were crossed with spuntag2 creating four populations used to study cry1ia1 segregation and efficacy. the cry1ia1 gene segregated in each of the four populations with a 1:1 ratio. all progeny that were polymerase chain reaction positive for t ...201323786096
cytotoxicity of the bacillus thuringiensis cry4b toxin is mediated by the cadherin receptor bt-r₃ of anopheles gambiae.we demonstrate for the first time the selective cytotoxicity of bacillus thuringiensis subsp. israelensis cry4b toxin mediated by bt-r₃ using a cell-based system, which employs high five insect cells stably expressing bt-r₃. discovery and validation of bt-r₃ as the cry4b receptor was accomplished using a web-based computational pipeline platform that facilitates high-throughput insecticidal target identification utilizing the anopheles gambiae genome. once the cry4b toxin binds to the bt-r₃ rece ...201323788176
insecticide resistance status in the major west nile virus vector culex pipiens from greece.one of the largest west nile virus outbreaks in europe occurred in greece in 2010. use of insecticides against culex pipiens was substantially scaled up, as an emergency tool. although mosquito control has been based on insecticides for several decades in greece, insecticide resistance data are not available.201423788440
heterologous expression and biochemical characterisation of fourteen esterases from helicoverpa armigera.esterases have recurrently been implicated in insecticide resistance in helicoverpa armigera but little is known about the underlying molecular mechanisms. we used a baculovirus system to express 14 of 30 full-length esterase genes so far identified from midgut cdna libraries of this species. all 14 produced esterase isozymes after native page and the isozymes for seven of them migrated to two regions of the gel previously associated with both organophosphate and pyrethroid resistance in various ...201323799064
identification of a second cytotoxic protein produced by bacillus thuringiensis a1470.bacillus thuringiensis a1470 produces multiple proteins with similar molecular masses (~30 kda) with cytotoxicity against human cell lines. one that was previously identified, parasporin-4, is a β-pore-forming toxin. the n-terminal sequence of a second cytotoxic protein was identical to a partial sequence of parasporin-2 produced by b. thuringiensis a1547. pcr was performed on total plasmid dna from a1470 by using primers for parasporin-2 to amplify a gene which was then cloned. the cloned gene ...201323801126
resistance and behavioural response of plutella xylostella (lepidoptera: plutellidae) populations to bacillus thuringiensis formulations.insecticide resistance is probably the major cause of control failure of plutella xylostella (l.) in brazil. in most production regions, the use of chemicals has been the prevalent method of control, with reduced efficacy through cropping seasons, even for the most recent use of products based on bacillus thuringiensis (bt). the current status of the resistance to these products was assessed, as well as the behavioural response of p. xylostella populations to bt sprays.201423813721
polyphosphate storage during sporulation in the gram-negative bacterium acetonema longum.using electron cryotomography, we show that the gram-negative sporulating bacterium acetonema longum synthesizes high-density storage granules at the leading edges of engulfing membranes. the granules appear in the prespore and increase in size and number as engulfment proceeds. typically, a cluster of 8 to 12 storage granules closely associates with the inner spore membrane and ultimately accounts for ∼7% of the total volume in mature spores. energy-dispersive x-ray spectroscopy (edx) analyses ...201323813732
purification and characterization of bacillus thuringiensis vegetative insecticidal toxin protein(s).bacillus thuringiensis subsp. aegypti c18 is an egyptian isolate, obtained from dead pink bollworm larvae. insecticidal active proteins against different insect were purified from btac18 strain during vegetative states. both the bacterial pellet and cell-free supernatant obtained during vegetative growth had insecticidal activity against black cutworm (bcw). bioassays revealed that the pellet after 48 h of growth is more potent and toxic against bcw. the toxin in the pellet was active at very hi ...201323815791
bacillus thuringiensis-derived cry5b has potent anthelmintic activity against ascaris suum.ascaris suum and ascaris lumbricoides are two closely related geo-helminth parasites that ubiquitously infect pigs and humans, respectively. ascaris suum infection in pigs is considered a good model for a. lumbricoides infection in humans because of a similar biology and tissue migration to the intestines. ascaris lumbricoides infections in children are associated with malnutrition, growth and cognitive stunting, immune defects, and, in extreme cases, life-threatening blockage of the digestive t ...201323818995
alteration in bacillus thuringiensis toxicity by curing gut flora: novel approach for mosquito resistance management.mosquitoes are known for acquiring resistance against insecticides in many ways, namely target side mutation, enzyme modification, sequestration, quick elimination, etc. but, the role of microflora present in abundance in the larval midgut is less explored with respect to their role in insecticide resistance. during the course of their development, mosquitoes are continuously exposed to microbes and have naturally acquired midgut microbial flora. this midgut flora can modulate the mosquito's sus ...201323820604
narrow terahertz attenuation signatures in bacillus thuringiensis.terahertz absorption signatures from culture-cultivated bacillus thuringiensis were measured with a thz photomixing spectrometer operating from 400 to 1200 ghz. we observe two distinct signatures centered at ∼955 and 1015 ghz, and attribute them to the optically coupled particle vibrational resonance (surface phonon-polariton) of bacillus spores. this demonstrates the potential of the thz attenuation signatures as "fingerprints" for label-free biomolecular detection.201423821459
bacillus thuringiensis colonises plant roots in a phylogeny-dependent manner.although much is known about the pathology of bacillus thuringiensis against invertebrates, current understanding of its natural ecology is limited. this study evaluated the biodiversity of b. thuringiensis in relation to its interaction with plants. phylogenetic relationships between 44 reference and field-collected strains, determined using 16s rrna and gyrb gene sequences, revealed a high degree of variability, similar to that found in databases. an arabidopsis thaliana in vitro inoculation m ...201323822207
characterization of a chitin-binding protein from bacillus thuringiensis hd-1.strains of bacillus thuringiensis produce insecticidal proteins. these strains have been isolated from diverse ecological niches, such as soil, phylloplane, insect cadavers and grain dust. to effectively propagate, these strains produce a range of molecules that facilitate its multiplication in a competing environment. in this report, we have examined synthesis of a chitin-binding protein and evaluated its effect on fungi encountered in environment and its interaction with insecticidal proteins ...201323824872
the resolution and regeneration of a cointegrate plasmid reveals a model for plasmid evolution mediated by conjugation and orit site-specific recombination.cointegrate plasmids are useful models for the study of plasmid evolution if their evolutionary processes can be replicated under laboratory conditions. pbmb0228, a 17 706 bp native plasmid originally isolated from bacillus thuringiensis strain ybt-1518, carries two nematicidal crystal protein genes, cry6aa and cry55aa. in this study, we show that pbmb0228 is in fact a cointegrate of two plasmids and contains two functional replication regions and two functional mobilization regions. upon introd ...201323826996
heat shock affects host-pathogen interaction in galleria mellonella infected with bacillus thuringiensis.we report that galleria mellonella larvae exposed to heat shock was more resistant to infection with entomopathogenic bacteria bacillus thuringiensis. the insects were exposed to a temperature of 40°c for 30 min directly before injection of vegetative bacterial cells. it appeared that the kinetics of the immune response was affected in heat-shocked animals. the infection-induced antimicrobial activity of larval hemolymph was stronger in shocked animals in comparison to the non-shocked ones. hemo ...201323834825
bacillus subtilis strain engineered for treatment of soil-transmitted helminth diseases.soil-transmitted helminths (hookworms, whipworms, and large roundworms) are agents of intestinal roundworm diseases of poverty that infect upwards of 2 billion people worldwide. a great challenge in treating these diseases is the development of anthelmintic therapeutics that are inexpensive, can be produced in great quantity, and are capable of delivery under varied and adverse environmental conditions. a potential solution to this challenge is the use of live bacteria that are acceptable for hu ...201323835175
a spodoptera exigua cadherin serves as a putative receptor for bacillus thuringiensis cry1ca toxin and shows differential enhancement of cry1ca and cry1ac toxicity.crystal toxin cry1ca from bacillus thuringiensis has an insecticidal spectrum encompassing lepidopteran insects that are tolerant to current commercially used b. thuringiensis crops (bt crops) expressing cry1a toxins and may be useful as a potential bioinsecticide. the mode of action of cry1a is fairly well understood. however, whether cry1ca interacts with the same receptor proteins as cry1a remains unproven. in the present paper, we first cloned a cadherin-like gene, secad1b, from spodoptera e ...201323835184
konagabase: a genomic and transcriptomic database for the diamondback moth, plutella xylostella.the diamondback moth (dbm), plutella xylostella, is one of the most harmful insect pests for crucifer crops worldwide. dbm has rapidly evolved high resistance to most conventional insecticides such as pyrethroids, organophosphates, fipronil, spinosad, bacillus thuringiensis, and diamides. therefore, it is important to develop genomic and transcriptomic dbm resources for analysis of genes related to insecticide resistance, both to clarify the mechanism of resistance of dbm and to facilitate the d ...201323837716
structural studies of a bacterial trna(his) guanylyltransferase (thg1)-like protein, with nucleotide in the activation and nucleotidyl transfer sites.all nucleotide polymerases and transferases catalyze nucleotide addition in a 5' to 3' direction. in contrast, trna(his) guanylyltransferase (thg1) enzymes catalyze the unusual reverse addition (3' to 5') of nucleotides to polynucleotide substrates. in eukaryotes, thg1 enzymes use the 3'-5' addition activity to add g-1 to the 5'-end of trna(his), a modification required for efficient aminoacylation of the trna by the histidyl-trna synthetase. thg1-like proteins (tlps) are found in archaea, bacte ...201323844012
dominant inheritance of field-evolved resistance to bt corn in busseolafusca.transgenic crops expressing bacillus thuringiensis (bt) toxins have been adopted worldwide, notably in developing countries. in spite of their success in controlling target pests while allowing a substantial reduction of insecticide use, the sustainable control of these pest populations is threatened by the evolution of resistance. the implementation of the "high dose/refuge" strategy for managing insect resistance in transgenic crops aims at delaying the evolution of resistance to bt crops in p ...201323844262
new combinations of cry genes from bacillus thuringiensis strains isolated from northwestern mexico.twenty eight bacillus thuringiensis strains isolated from the tijuana-ensenada region of northwestern mexico were analyzed to determine the distribution of cry and cyt genes. crystal production by the strains was examined by scanning electron microscopy, which showed the predominance of cubic crystals. alkaline-dissolved and trypsin activated crystals were also analyzed by sds-page, yielding bands of 40-200 kda. the cry1 and cry2 genes were molecularly characterized using general and newly desig ...201223844480
new and old microbial communities colonizing a seventeenth-century wooden church.the north of romania is known for its wooden churches dating from the seventeenth and eighteenth centuries. their deterioration constitutes a major problem due to their value for the cultural heritage. the microbial community from a seventeenth-century wooden church (nicula, romania) was investigated by characterization of uncultivated and cultivated bacteria using 16s rdna sequence analysis. the study revealed not only the prevalence of the bacillus thuringiensis strain iam 12077 but also the p ...201423846554
a novel bacillus thuringiensis cry-like protein from a rare filamentous strain promotes crystal localization within the exosporium.mutation of a novel cry-like gene (cry256) from bacillus thuringiensis resulted in a protein crystal, normally located within the spore's exosporium, being found predominately outside the exosporium. the cry256 gene codes for a 3-domain cry-like protein that does not correspond to any of the known cry protein holotypes.201323851091
transfer efficiency of bacteria and viruses from porous and nonporous fomites to fingers under different relative humidity conditions.fomites can serve as routes of transmission for both enteric and respiratory pathogens. the present study examined the effect of low and high relative humidity on fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (fomites). nine fomites representing porous and nonporous surfaces of different compositions were studied. escherichia coli, staphylococcus aureus, bacillus thuringiensis, ms2 coliphage, and poliovirus 1 were placed on fomites in 10-μl d ...201323851098
shared midgut binding sites for cry1a.105, cry1aa, cry1ab, cry1ac and cry1fa proteins from bacillus thuringiensis in two important corn pests, ostrinia nubilalis and spodoptera frugiperda.first generation of insect-protected transgenic corn (bt-corn) was based on the expression of cry1ab or cry1fa proteins. currently, the trend is the combination of two or more genes expressing proteins that bind to different targets. in addition to broadening the spectrum of action, this strategy helps to delay the evolution of resistance in exposed insect populations. one of such examples is the combination of cry1a.105 with cry1fa and cry2ab to control o. nubilalis and s. frugiperda. cry1a.105 ...201323861865
effect of chemical additives on bacillus thuringiensis (bacillales: bacillaceae) against plutella xylostella (lepidoptera: pyralidae).to examine the effect of chemical additives on bacillus thuringiensis (berliner) against plutella xylostella (l.), inorganic salts, nitrogenous compounds, protein solubilizing agents, and organic acids were selected and tested. the chosen materials are low in cost and environmentally safe. results show that many inorganic salts can increase the activity of b. thuringiensis in a range of 1.31- to 3.08-fold. these include calcium acetate, calcium chloride, calcium hydroxide, calcium sulfate, calci ...201323865169
different toxicity of the novel bacillus thuringiensis (bacillales: bacillaceae) strain llp29 against aedes albopictus and culex quinquefasciatus (diptera: culicidae).bacillus thuringiensis (bt) (berliner) strain llp29 produces a crystal protein cyt1aa6 toxic to mosquito vectors of human diseases. however, the susceptibility of culex quinquefasciatus (say) in the current study was 8.25 times higher than that of aedes albopictus (skuse) with this single protein cyt1aa6 purified from llp29. to understand the mechanism of the novel mosquitocidal protein, the binding characteristic of brush border membrane vesicles from the two tested mosquitoes was investigated. ...201323865172
corn earworm (lepidoptera: noctuidae) in northeastern field corn: infestation levels and the value of transgenic hybrids.corn earworm, helicoverpa zea (boddie), is a polyphagous noctuid pest of agricultural crops across the united states that is gaining attention as a pest of field corn. before the introduction of transgenic insect-resistant hybrids, this pest was largely ignored in field corn, but now many bacillus thuringiensis (bt) corn hybrids have activity against corn earworm. however, the value of control in the northeastern united states is unclear because the risk posed by corn earworm to field corn has n ...201323865190
host-parasite coevolution favours parasite genetic diversity and horizontal gene transfer.host-parasite coevolution is predicted to favour genetic diversity and the underlying mechanisms (e.g. sexual reproduction and, more generally, genetic exchange), because diversity enhances the antagonists' potential for rapid adaptation. to date, this prediction has mainly been tested and confirmed for the host. it should similarly apply to the parasite. indeed, our previous work demonstrated that experimental coevolution between the nematode caenorhabditis elegans and its microparasite bacillu ...201323865952
the effect of nitrogen rate on transgenic corn cry3bb1 protein expression.combining herbicide-resistant and bacillus thuringiensis (bt) traits in corn (zea mays l.) hybrids may affect insect resistance management owing to volunteer corn. some bt toxins may be expressed at lower levels by nitrogen-deficient corn roots. corn plants with sublethal levels of bt expression could accelerate the evolution of bt resistance in target insects. the present objective was to quantify the concentration of bt (cry3bb1) in corn root tissue with varying tissue nitrogen concentrations.201423868342
evaluation of real-time pcr detection methods for detecting rice products contaminated by rice genetically modified with a cpti-kdel-t-nos transgenic construct.genetically modified (gm) rice (oryza sativa) lines, such as insecticidal kefeng and kemingdao, have been developed and found unauthorised in processed rice products in many countries. therefore, qualitative detection methods for the gm rice are required for the gm food regulation. a transgenic construct for expressing cowpea (vigna unguiculata) trypsin inhibitor (cpti) was detected in some imported processed rice products contaminated with kemingdao. the 3' terminal sequence of the identified t ...201323871003
analyses of α-amylase and α-glucosidase in the malaria vector mosquito, anopheles gambiae, as receptors of cry11ba toxin of bacillus thuringiensis subsp. jegathesan.bacillus thuringiensis subsp. jegathesan produces cry11ba crystal protein with high toxicity to mosquito larvae. the cry11ba toxicity is dependent on its receptors on mosquito larval midgut epithelial cells. previously, a cadherin-like protein (agcad2), aminopeptidase (agapn2) and alkaline phosphatase (agalp1) were reported to be involved in regulation of cry11ba toxicity on anopheles gambiae larvae. here, the cdnas encoding α-amylase (agamy1) and α-glucosidase (agm3) were cloned from a. gambiae ...201323872242
the influence of insecticides on the viability of entomopathogenic nematodes (rhabditida: steinernematidae and heterorhabditidae) under laboratory conditions.in order to increase our knowledge on the susceptibility of entomopathogenic nematode (epn) species to agrochemicals, the compatibility of the infective juveniles (ijs) of the epn (steinernema and heterorhabditis) with eight chemical and bio-insecticides was investigated under laboratory conditions. the effect of direct ij exposure to insecticides for 6 and 24 h was tested in a petri dish at 15, 20 and 25 °c.201423873740
diminishing returns from increased percent bt cotton: the case of pink bollworm.regional suppression of pests by transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt) has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of bt crops. here we address this issue by analyzing 16 years of field data on pink bollworm (pectinophora gossypiella) population density and percentage of bt cotton in the yangtze river valley of china. in this regi ...201323874678
effect of larvae treated with mixed biopesticide bacillus thuringiensis-abamectin on sex pheromone communication system in cotton bollworm, helicoverpa armigera.third instar larvae of the cotton bollworm (helicoverpa armigera) were reared with artificial diet containing a bacillus thuringiensis-abamectin (bta) biopesticide mixture that resulted in 20% mortality (ld20). the adult male survivors from larvae treated with bta exhibited a higher percentage of "orientation" than control males but lower percentages of "approaching" and "landing" in wind tunnel bioassays. adult female survivors from larvae treated with bta produced higher sex pheromone titers a ...201323874751
immune-related transcriptome of coptotermes formosanus shiraki workers: the defense mechanism.formosan subterranean termites, coptotermes formosanus shiraki, live socially in microbial-rich habitats. to understand the molecular mechanism by which termites combat pathogenic microbes, a full-length normalized cdna library and four suppression subtractive hybridization (ssh) libraries were constructed from termite workers infected with entomopathogenic fungi (metarhizium anisopliae and beauveria bassiana), gram-positive bacillus thuringiensis and gram-negative escherichia coli, and the libr ...201323874972
agrotis segetum midgut putative receptor of bacillus thuringiensis vegetative insecticidal protein vip3aa16 differs from that of cry1ac toxin.considering the fact that agrotis segetum is one of the most pathogenic insects to vegetables and cereals in the world, particularly in africa, the mode of action of vip3aa16 of bacillus thuringiensis bupm95 and cry1ac of the recombinant strain bns3cry-(phtcry1ac) has been examined in this crop pest. a. segetum proteases activated the vip3aa16 protoxin (90kda) yielding three bands of about 62, 45, 22kda and the activated form of the toxin was active against this pest with an lc50 of about 86ng/c ...201323876657
efficacy of various larvicides against aedes aegypti immatures in the laboratory.we conducted a laboratory study to evaluate the efficacy of control agents against small larvae, large larvae, and pupae of aedes aegypti to determine an appropriate larvicide regime to employ in emergency dengue control programs. the control agents included bacillus thuringiensis var. israelensis (bti), pyriproxyfen (an insect growth regulator), a larvicidal oil, aquatain amf (polydimethylsiloxane, a monomolecular film), and temephos at the recommend application dosages and rates. our results s ...201323883850
norway spruce (picea abies) genetic transformation with modified cry3a gene of bacillus thuringiensis.modified versions of the cry3a gene of bacillus thuringiensis (bt) were transferred into norway spruce (picea abies). both the biolistic approach and agrobacterium tumefaciens mediated procedure were employed for transformation of embryogenic tissue (et) cultures. the latter method proved to be more efficient yielding 70 transgenic embryogenic tissue lines compared with 18 lines obtained by biolistics. the modified cry3a genes were driven by a 35s promoter and the nptii screenable selection mark ...201323888296
differentiation of strains from the bacillus cereus group by rflp-pfge genomic fingerprinting.bacillus mycoides, bacillus pseudomycoides, bacillus weihenstephanensis, bacillus anthracis, bacillus thuringiensis, and bacillus cereus belong to the b. cereus group. the last three species are characterized by different phenotype features and pathogenicity spectrum, but it has been shown that these species are genetically closely related. the macrorestriction analysis of the genomic dna with the noti enzyme was used to generate polymorphism of restriction profiles for 39 food-borne isolates (b ...201323893780
dna sequencing reveals the midgut microbiota of diamondback moth, plutella xylostella (l.) and a possible relationship with insecticide resistance.insect midgut microbiota is important in host nutrition, development and immune response. recent studies indicate possible links between insect gut microbiota and resistance to biological and chemical toxins. studies of this phenomenon and symbionts in general have been hampered by difficulties in culture-based approach. in the present study, dna sequencing was used to examine the midgut microbiota of diamondback moth (dbm), plutella xylostella (l.), a destructive pest that attacks cruciferous c ...201323894355
bacteriocins of bacillus thuringiensis can expand the potential of this bacterium to other areas rather than limit its use only as microbial insecticide.various strains of bacillus thuringiensis are among the most successful entomopathogenic bacteria used commercially as biopesticides owing to their ability to synthesize insecticidal crystal (cry) and cytolytic (cyt) protein toxins during sporulation, and vegetative insecticidal (vips) proteins during the vegetative phase of growth. whereas much is known about the molecular biology of cry, cyt, and vips, comparatively little is known about other proteins and metabolites synthesized by b. thuring ...201323898994
no effects of bacillus thuringiensis maize on nontarget organisms in the field in southern europe: a meta-analysis of 26 arthropod taxa.maize with the insecticidal properties of the entomopathogenic bacterium bacillus thuringiensis berliner, known as bt maize, has been sown in europe since 1998. for several years, eu and spanish regulations have required laboratory and field trials to assess risks of genetically modified crops for nontarget organisms prior to their authorization. thirteen field trials were conducted in spain to measure the effects of bt maize on a broad range of arthropod taxa; no effects were found in accordanc ...201423904218
molecular characterization of a short peptidoglycan recognition protein (pgrp-s) from asian corn borer (ostrinia furnacalis) and its role in triggering propo activity.peptidoglycan recognition proteins (pgrps) are non-specific immune molecules of insects, and vertebrates etc., but are not present in plants and nematodes. in the current experiment, a pgrp dna sequence (2,910 bp containing four exons) was identified from genomic dna library of asian corn borer, ostrinia furnacalis, and a full-length cdna programming pgrp was cloned (designed as ofpgrp-s) with an open reading frame of 579 bp, having 192 amino acid. this inferred amino acid sequence showed maximu ...201423907718
combinatorial effect of bacillus thuringiensis kurstaki and photorhabdus luminescens against spodoptera littoralis (lepidoptera: noctuidae).spodoptera littoralis, one of the major pests of many important crop plants, is more susceptible to bacillus thuringiensis aizawai delta-endotoxins than to those of bacillus thuringiensis kurstaki. within the framework of the development of efficient bioinsecticides and the prevention against insect resistance, we tested the effect of mixing b. thuringiensis kurstaki delta-endotoxins and photorhabdus luminescens cells on s. littoralis growth. the obtained results showed that the growth inhibitio ...201423908000
contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to uv-a.mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure ...201323911355
promise for plant pest control: root-associated pseudomonads with insecticidal activities.insects are an important and probably the most challenging pest to control in agriculture, in particular when they feed on belowground parts of plants. the application of synthetic pesticides is problematic owing to side effects on the environment, concerns for public health and the rapid development of resistance. entomopathogenic bacteria, notably bacillus thuringiensis and photorhabdus/xenorhabdus species, are promising alternatives to chemical insecticides, for they are able to efficiently k ...201323914197
new role for dcr-1/dicer in caenorhabditis elegans innate immunity against the highly virulent bacterium bacillus thuringiensis db27.bacillus thuringiensis produces toxins that target invertebrates, including caenorhabditis elegans. virulence of bacillus strains is often highly specific, such that b. thuringiensis strain db27 is highly pathogenic to c. elegans but shows no virulence for another model nematode, pristionchus pacificus. to uncover the underlying mechanisms of the differential responses of the two nematodes to b. thuringiensis db27 and to reveal the c. elegans defense mechanisms against this pathogen, we conducte ...201323918784
comparison between diflubenzuron and a bacillus thuringiensis israelensis- and lysinibacillus sphaericus-based formulation for the control of mosquito larvae in urban catch basins in switzerland.a field test was conducted to evaluate a commercial biolarvicide based on bacillus thuringiensis var. israelensis and lysinibacillus sphaericus to control mosquitoes breeding in catch basins in southern switzerland. the efficacy and residual activity of the microbial mosquito larvicide applied at the recommended rate of 10 g per catch basin was compared to the currently used larvicide diflubenzuron. both products provided a very good control activity (> 97% of reduction) of late instars (3rd and ...201323923328
d-cycloserine or similar physiochemical compounds may be uniquely suited for use in bacillus anthracis spore decontamination strategies.as observed in the aftermath of the anthrax attacks of 2001, decontamination and remediation of a site contaminated by the accidental or intentional release of bacillus anthracis spores is difficult, costly and potentially damaging to the environment. the identification of novel strategies that neutralize the threat of spores while minimizing environmental damage remains a high priority. we investigated the efficacy of d-cycloserine (dcs), an antibiotic and inhibitor of the spore-associated enzy ...201323927578
midgut aminopeptidase n isoforms from ostrinia nubilalis: activity characterization and differential binding to cry1ab and cry1fa proteins from bacillus thuringiensis.aminopeptidase n (apn) isoforms from lepidoptera are known for their involvement in the mode of action of insecticidal cry proteins from bacillus thuringiensis. these enzymes belong to a protein family with at least eight different members that are expressed simultaneously in the midgut of lepidopteran larvae. here, we focus on the characterization of the apns from ostrinia nubilalis (onapns) to identify potential cry receptors. we expressed onapns in insect cells using a baculovirus system and ...201323933214
inheritance of cry1f resistance, cross-resistance and frequency of resistant alleles in spodoptera frugiperda (lepidoptera: noctuidae).transgenic maize, zea maize l., expressing the cry1f protein from bacillus thuringiensis has been registered for spodoptera frugiperda (j. e. smith) control since 2003. unexpected damage to cry1f maize was reported in 2006 in puerto rico and cry1f resistance in s. frugiperda was documented. the inheritance of cry1f resistance was characterized in a s. frugiperda resistant strain originating from puerto rico, which displayed >289-fold resistance to purified cry1f. concentration-response bioassays ...201323941623
activity of a brazilian strain of bacillus thuringiensis israelensis against the cotton boll weevil anthonomus grandis boheman (coleoptera: tenebrionidae).a brazilian bacillus thuringiensis subspecies israelensis, toxic to diptera, including mosquitoes, was found also to show toxicity to the coleopteran boll weevil anthonomus grandis boheman at an equivalent level to that of the standard coleopteran-active b. thuringiensis subspecies tenebrionis t08017. recombinant b. thuringiensis strains expressing the individual cyt1aa, cry4aa, cry4ba and cry11aa toxins from this strain were assessed to evaluate their potential contribution to the activity agai ...201223950011
mosquito autogeny in aedes caspius (diptera: culicidae): alterations of larval nourishments reservation upon bacterial infection.the present study recorded mosquito autogeny for the first time amongst aedes caspius species in the eastern region of saudi arabia. laboratory rearing showed an obligatory autogenous species of ae. caspius since it foregoes blood feeding during its first ovarian cycle, even in the presence of the hosts (cd mouse), but produces its second egg batch only if ingested a blood meal. both morphological and molecular identification confirmed that both autogenous and anautogenous strains belong to the ...201323955943
tolerance to individual and joint effects of arsenic and bacillus thuringiensis subsp. israelensis or lysinibacillus sphaericus in culex mosquitoes.arsenic contamination of global water supplies has come to the forefront in policy decisions in recent decades. however, the effects of arsenic on lower trophic levels of insects inhabiting contaminated ecosystems are not well understood. one approach to document both acute and sublethal effects of toxicants like arsenic is to assay them in combination with microbial pathogens to evaluate shifts in survival curves of the test organisms. larvae of culex quinquefasciatus and culex tarsalis were re ...201423956096
characterization of atg8 in lepidopteran insect cells.yeast atg8 and mammalian microtubule-associated protein light chain 3 (lc3) are landmark proteins essential for autophagy. here the lepidopteran atg8, a homolog of lc3, is characterized. sequence analysis reveals that atg8 proteins are highly conserved in lepidopteran species. the abundance of endogeous atg8 and the ratios of atg8 conjugation to phosphatidylethanolamine (atg8-pe)/atg8 are different among several lepidopteran cell lines and different tissues of helicoverpa armigera larvae. both t ...201323959953
analysis of dna structure and sequence requirements for pseudomonas aeruginosa mutl endonuclease activity.the hallmark of the mismatch repair system in bacterial and eukaryotic organisms devoid of muth is the presence of a mutl homologue with endonuclease activity. the aim of this study was to analyse whether different dna structures affect pseudomonas aeruginosa mutl (pamutl) endonuclease activity and to determine if a specific nucleotide sequence is required for this activity. our results showed that pamutl was able to nick covalently closed circular plasmids but not linear dna at high ionic stren ...201323969026
three dimensional (3d) structure prediction and substrate-protein interaction study of the chitin binding protein cbp24 from b. thuringiensis.bacillus thuringiensis is an insecticidal bacterium whose chitinolytic system has been exploited to improve insect resistance in crops. in the present study, we studied the cbp24 from b. thuringiensis using homology modeling and molecular docking. the primary and secondary structure analyses showed cbp24 is a positively charged protein and contains single domain that belongs to family cbm33. the 3d model after refinement was used to explore the chitin binding characteristics of cbp24 using autod ...201323976829
essential role of amino acids in αd-β4 loop of a bacillus thuringiensis cyt2aa2 toxin in binding and complex formation on lipid membrane.bacillus thuringiensis subsp. darmstadiensis produces cyt2aa2 toxin that shows in vivo specific toxicity against dipteran insect larvae but exhibits in vitro cytolytic activity to a broad-spectrum of cells including red blood cells. two mutant toxins have been generated by introducing a small hydrophobic alanine into positions thr-144 and asn-145 in αd-β4 loop. both mutants were highly expressed as crystalline inclusions that were solubilized in alkaline conditions and processed by chymotrypsin ...201323988392
an improved pcr-restriction fragment length polymorphism (rflp) method for the identification of cry1-type genes.the cry1-type genes of bacillus thuringiensis represent the largest cry gene family, which contains 50 distinct holotypes. it is becoming more and more difficult to identify cry1-type genes using current methods because of the increasing number of cry1-type genes. in the present study, an improved pcr-restriction fragment length polymorphism (pcr-rflp) method which can distinguish 41 holotypes of cry1-type genes was developed. this improved method was used to identify cry1-type genes in 20 b. th ...201323995930
validation of an extraction method for cry1ab protein from soil.corn expressing insecticidal proteins derived from bacillus thuringiensis (bt corn) has increased in usage in the united states from 8% of total corn acreage in 1996 to 67% in 2012. because of this increase, it is important to be able to monitor the fate and transport of the insecticidal bt proteins to evaluate environmental exposure and effects. accurate and validated methods are needed to quantify these proteins in environmental matrices. a method to extract bt cry1ab proteins from 3 soil type ...201423996731
molecular characterization of novel serovars of bacillus thuringiensis isolates from india.novel bacillus thuringiensis isolates gs4, gn24 and up1 were isolated and characterized by determination of serotyping, insecticidal protein by sds-page, plasmid composition, cry gene content and insect toxicity. serologically two isolates gs4 and up1 were allocated to the h3abce which is a new serovar while isolate gn24 was of h3ab type. isolate gs4 produced flat crystal inclusions while up1 produced cuboidal crystals. pcr analysis found that both isolates contained cry1 and cry1ac genes. the m ...201223997321
characterization of insecticidal genes of bacillus thuringiensis strains isolated from arid environments.this study aimed at characterizing the insecticidal genes of eight bacillus thuringiensis isolates that were recovered from the local environment of western saudi arabia. the screening for the presence of lepidopteran-specific cry1a family and vip3a genes, dipteran-specific cry4 family and coleopteran-specific cry3a, vip1a and vip2a genes, was carried out by pcr. all eight isolates produced pcr products that confirmed the presence of cry1aa, cry1ab, cry1ac, cry4a, cry4b genes, but not cry3a, vip ...201223997347
a protein engineering of bacillus thuringiensis δ-endotoxin by conjugating with 4"-o-succinoyl abamectin.conjugation of bacillus thuringiensis δ-endotoxin (bt toxin) with other toxins for insect pest control has been proposed as a new efficient strategy with increasing insecticidal toxicity and target range and delay the onset of insect resistance. a modified method was investigated by conjugating bt toxin with 4"-o-succinoyl abamectin to form a new biocide which was named as bta. 'zero-length' cross-linker edc in combination with nhs activated 4"-o-succinoyl abamectin and extended half-life period ...201323999013
comparative binding of cry1ab and cry1f bacillus thuringiensis toxins to brush border membrane proteins from ostrinia nubilalis, ostrinia furnacalis and diatraea saccharalis (lepidoptera: crambidae) midgut tissue.the european (ostrinia nubilalis hübner) and asian corn borers (ostrinia furnacalis guenée) are closely related and display similar sensitivity to cry1 toxins. in this study, we compared the binding patterns of cry1ab and cry1f toxins between both ostrinia spp., as well as the expression of putative cadherin- and aminopeptidase-n (apn)-like protein receptors. additionally, cdna sequences of these putative toxin receptors from both ostrinia species were compared. ligand blots for both species ind ...201323999243
the impact of strain diversity and mixed infections on the evolution of resistance to bacillus thuringiensis.pesticide mixtures can reduce the rate at which insects evolve pesticide resistance. however, with live biopesticides such as the naturally abundant pathogen bacillus thuringiensis (bt), a range of additional biological considerations might affect the evolution of resistance. these can include ecological interactions in mixed infections, the different rates of transmission post-application and the impact of the native biodiversity on the frequency of mixed infections. using multi-generation sele ...201324004937
[physico-chemical properties of bacillus thuringiensis imv b-7324 fibrinolytic peptidase].investigations of physico-chemical properties of the bacillus thuringiensis imv b-7324 fibrinolytic peptidase showed that optimal activity of enzyme displayed at ph 10.0 and temperature 60 degrees c. stability of peptidase retained in the range of ph from 6.0 to 11.0 and temperature from 20 to 50 degrees c over 1 h. inhibition of fibrinolytic peptidase activity by ethylene glycol tetraacetic acid (egta) and tetrasodium salt of ethylenediaminetetraacetic acid (trilon b) indicates the belonging of ...201324006777
identification, cloning and expression of an insecticide cry8 gene from bacillus thuringiensis inta fr7-4.insecticidal activity of bacillus thuringiensis is attributed largely to the crystal proteins. these were found with specific toxic activity against insects in different orders. a novel cry8 gene from b. thuringiensis strain inta fr7-4 from argentina was characterized. the encoded protein, cry8qa2, is 1184 amino acids long and its sequence is more similar to those of cry8f class. we cloned and expressed the protein in an acrystalliferous strain of b. thuringiensis using two differentially regula ...201324008260
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