| a new serotype of bacillus thuringiensis from colombia toxic to mosquito larvae. | during a survey conducted in colombia a new isolate of bacillus thuringiensis that showed toxicity toward culex quinquefasciatus, cx. pipiens, aedes aegypti, and anopheles stephensi larvae was isolated. parasporal crystals were spherical in shape and showed a great degree of similarity with those produced by the reference strain of bacillus thuringiensis subsp. israelensis. supernatant fraction of the whole culture was not toxic, and heat-stable exotoxin production was negative. catalase, urease ... | 1992 | 1347310 |
| the parasporal inclusion of bacillus thuringiensis subsp. shandongiensis: characterization and screening for insecticidal activity. | the parasporal body of bacillus thuringiensis subsp. shandongiensis was characterized in terms of its structure, protein composition, and toxicological properties against several types of insects. the crystals of b. thuringiensis shandongiensis appear to consist of a major protein of 144 kda present in an spherical inclusion, as determined by transmission electron microscopy, titration curve analysis, and sds-page of the solubilized crystals. a second protein of ca. 60 kda is present in trace am ... | 1992 | 1351504 |
| biological control of mosquitoes and other biting flies by bacillus sphaericus and bacillus thuringiensis. | | 1992 | 1352283 |
| involvement of a possible chaperonin in the efficient expression of a cloned cryiia delta-endotoxin gene in bacillus thuringiensis. | the bacillus thuringiensis cryiia delta-endotoxin gene is found as the third-gene in a three-gene operon, with a sporulation-dependent promoter lying upstream of the first gene, orf1. we show here that the polypeptide product of the middle gene (orf2) is required for efficient expression of the toxin gene. in the absence of a functional orf2 polypeptide the toxin does not form the crystalline inclusions characteristic of other known bacillus thuringiensis toxins. we discuss the importance of thi ... | 1992 | 1352615 |
| [the efficacy of a combined preparation based on bacillus sphaericus and bac. thuringiensis h-14 against the larvae of blood-sucking mosquitoes]. | the optimal bactoculicide/sphaerolarvicide ratio in combination using against aedes aegypti larvae was established in laboratory by selection. the field trials of the selected bs/bt sample containing the ingredients in titer: bactoculicide-83, sphaerolarvicide-17 were conducted in the arid area of central asia. with 1 g/m2, complete mortality of culex, aedes and anopheles larvae was obtained with the residual larvicidal action of 15 days. it is recommended to carry out more large-scale trials of ... | 1992 | 1354836 |
| comparison of bacillus thuringiensis subsp. israelensis cryiva and cryivb cloned toxins reveals synergism in vivo. | when the gene for the mosquitocidal protein cryiva was expressed in two strains of bacillus thuringiensis (bt) cured of their resident delta-endotoxin genes, the protein accumulated as large inclusions. the inclusions produced in the bt subsp. kurstaki recipient strain were twice as soluble at alkaline ph as the inclusions produced in bt subsp. israelensis. solubilized protoxins were activated by treatment with mosquito gut extracts or trypsin for varying lengths of time and tested for in vitro ... | 1992 | 1355748 |
| a broad-spectrum cytolytic toxin from bacillus thuringiensis var. kyushuensis. | bacillus thuringiensis (bt) var. kyushuensis synthesizes a mosquitocidal crystalline inclusion containing several proteins ranging from 140 to 14 kda. we have identified a 25 kda protein protoxin in this inclusion which is not cytolytic, but when activated proteolytically to 23-22 kda products is cytolytic to mosquito, lepidopteran and mammalian cells, can release entrapped glucose from liposomes and forms cation-selective channels in a planar lipid bilayer. this broad-spectrum cytolytic toxin i ... | 1992 | 1355907 |
| host range of clostridium bifermentans serovar. malaysia, a mosquitocidal anaerobic bacterium. | clostridium bifermentans serovar. malaysia (c.b.m.) is toxic to mosquito larvae. in this study, we quantified its toxicity to the mosquitoes, aedes aegypti, ae. albopictus, ae. caspius, ae. detritus, anopheles stephensi, an. gambiae, culex pipiens and cx. quinquefasciatus. anopheles larvae are the most susceptible, followed by ae. detritus and ae. caspius, then culex and other aedes larvae. according to mosquito species, the lc50 varies from 7 x 10(3) to 1.3 x 10(6) cells/ml. three concentration ... | 1992 | 1357087 |
| factors influencing the activity of bacillus thuringiensis var. israelensis treatments. | environmental factors influence the effectiveness of microbial control agents in mosquito control programs. four of these factors (water temperature, larval density, sunlight and the effect of associated filter feeders) were studied with bacillus thuringiensis var. israelensis under laboratory and semifield conditions in europe using different instars of aedes vexans, ae. aegypti and culex pipiens. bioassays conducted at a low temperature (5 degrees c) yielded 10-fold higher lc50 and lc90 values ... | 1992 | 1357088 |
| toxicity and residual action of the photoactivated compound, cyano-alpha-terthienyl, and its efficacy for reducing pre-imaginal populations of mosquitoes. | the photoactivated compound, cyano-alpha-terthienyl (cyano-alpha-t), was highly toxic to pre-imagines of the mosquitoes culex restuans, cx. tarsalis and culiseta inornata when synergized with piperonyl butoxide (pbo). lethal concentrations for 50% mortality, determined during an outdoor trial using caged fourth-instar culex spp. larvae, were 19.4, 15.4 and 12.9 g/ha at 24, 48 and 72 h after treatment, respectively. no residual activity of cyano-alpha-t was observed beyond 24 h following treatmen ... | 1992 | 1359007 |
| t cell maturation stage-linked heterogeneity of the glycosylphosphatidylinositol membrane anchor of thy-1. | we showed that some of thy-1 molecules on murine thymocytes are resistant to phosphatidylinositol-specific phospholipase c (pi-plc) derived from bacillus thuringiensis. both immature thymocytes with low cd3 expression and mature thymic t lymphocytes with high cd3 expression carried the pi-plc-resistant thy-1, and the pi-plc-sensitivity of thy-1 extensively varied among thymocyte subpopulations. in contrast, the same pi-plc fully hydrolysed the anchor of thy-1 on peripheral t lymphocytes. when th ... | 1992 | 1360444 |
| sensitivity of mosquito-pathogenic bacterial strains to various antibodies. | four strains of bacillus sphaericus, 1593, 2362, 9001 and 9002, b. thuringiensis h-14 and b. thuringiensis neoleonensis were tested for sensitivity against 18 antibiotics. the results revealed that all the four strains of b. sphaericus are resistant to colistin, nalidixic acid, polymyxin b and streptomycin. however, b. thuringiensis h-14 was resistant to 9 antibiotics, viz. ampicillin, cephalexin, carbenicillin, co-trimoxazole, colistin, cloxacillin, penicillin, nitrofurantoin and polymyxin b wh ... | 1992 | 1363415 |
| [an evaluation of the genotoxicity activity of the microbial preparation bulmoscide]. | the genotoxic activity of the microbial preparation bulmoscid "in vivo" for somatic cells of mammals is studied by micronucleus method in marrow of mice. the experiments are performed on inbred mice c57bl6 of both sexes at unrepeated oral introduction of the preparation in two doses: 2200 mg/kg-1 (2.64.10(10) cells kg-1), and 1100 mg/kg-1 (1.32.10(10) cells kg-1) presenting 80% and respectively 40% of the unrepeated maximum tolerable dose of "bulmoscid" for mice (2750 mg/kg-1). the genotoxic ind ... | 1992 | 1364531 |
| [the acute toxicity of the microbial preparation bulmoscide]. | the acute toxicity of a new bulgarian microbial preparation bulmoscid on the basis of bacillus thuringiensis h-14 in the conditions of oral, dermal, inhalation and intraperitoneal introduction in experimental animals is determined. the assessment of toxicity is made by using toxicometric, integral, hematologic, histologic and microbiologic methods in accordance with bulgarian and international criteria and standards. it is established, that the preparation bulmoscid introduced orally in dose 550 ... | 1992 | 1364532 |
| insect resistant cotton plants. | we have expressed truncated forms of the insect control protein genes of bacillus thuringiensis var. kurstaki hd-1(cryia(b) and hd-73 (cryia(c) in cotton plants at levels that provided effective control of agronomically important lepidopteran insect pests. total protection from insect damage of leaf tissue from these plants was observed in laboratory assays when tested with two lepidopteran insects, an insect relatively sensitive to the b.t.k. insect control protein, trichoplusia ni (cabbage loo ... | 1990 | 1366777 |
| genetic manipulation of bacillus thuringiensis insecticidal crystal protein genes in bacteria. | | 1991 | 1367416 |
| insecticidal activity and processing in larval gut juices of genetically engineered 130-kda proteins of bacillus thuringiensis subsp. aizawai. | the 130-kda insecticidal protein (ip) of bacillus thuringiensis subsp. aizawai is proteolytically processed in the gut juice of susceptible insect larvae to yield an insecticidally active 60-kda fragment. twenty-seven mutant ip genes with the replacement of codons for arg and lys with codons for gln in the active fragment and its adjacent regions of the 130-kda ip were constructed by site-directed mutagenesis and expressed in escherichia coli cells. the produced mutant ips at arg87, arg131, arg1 ... | 1992 | 1368122 |
| construction of chimeric insecticidal proteins between the 130-kda and 135-kda proteins of bacillus thuringiensis subsp. aizawai for analysis of structure-function relationship. | eight chimeric insecticidal protein (ip) genes were constructed between the 130-kda and 135-kda ip genes of bacillus thuringiensis subsp. aizawai, and expressed in escherichia coli jm103 cells. the characterization of the produced chimeric ips indicated that the variable region (vr1) in the amino-terminal half of the ips is responsible for the insecticidal activity against larvae of spodoptera litura and plutella xylostella. the carboxy-terminal half of vr1 was important for the formation of the ... | 1990 | 1368534 |
| effects of bacillus thuringiensis var. israelensis 20-kda protein on production of the bti 130-kda crystal protein in escherichia coli. | a 20-kda protein of bacillus thuringiensis var. israelensis (bti) has been shown to be necessary for the efficient expression of the 27-kda mosquitocidal protein gene in escherichia coli. we have investigated the effects of this 20-kda protein on the expression of two 130-kda mosquitocidal protein genes (cryiva, cryivb) in e. coli by supplying the 20-kda protein gene in trans. when a recombinant plasmid, plh4bx, which was constructed to express cryiva under the e. coli lac promoter on puc19, coe ... | 1992 | 1368950 |
| are b.t.k. plants really safe to eat? | | 1990 | 1369294 |
| design and use of synthetic oligonucleotide probes in the cloning of delta-endotoxin genes from bacillus thuringiensis. | a detailed protocol is described for the design and use of synthetic oligonucleotide probes for screening dna libraries from bacillus thuringiensis var. kurstaki (strain hd191) for copies of the gene (tox) encoding the insecticidal delta-endotoxin. two homologous tox genes were identified in this organism; one of these was located on a 75-kb plasmid and the other on a second large plasmid or the bacterial chromosome. a tox gene was isolated as a 6.5-kb hindiii fragment of b. thuringiensis plasmi ... | 1991 | 1369333 |
| expansion of insecticidal host range of bacillus thuringiensis by in vivo genetic recombination. | we describe a novel approach for the insertion of an insecticidal toxin gene into a resident plasmid in bacillus thuringiensis (bt). a gene encoding a coleopteran-specific toxin was cloned within a fragment of is232 and inserted into a plasmid thermosensitive for replication in bt. the plasmid was used to transform a bt strain toxic to lepidoptera, and the transformants were then selected at non-permissive temperature for clones in which the vector had integrated into a copy of is232 present on ... | 1992 | 1369394 |
| hyperthermic potentiation of bleomycin cytotoxicity in the presence of bacillus thuringiensis subsp. israelenis delta-endotoxin. | we previously reported that a 25-kda bacillus thuringiensis subsp. israelensis (bti) delta-endotoxin potentiated the antitumor activity of bleomycin (blm) in both in vitro and in vivo systems. we report here a characteristic hyperthermic synergy toward the cytocidal activity of blm in the presence of bti endotoxin in cultured l1210 cells. cytocidal gain, i.e., the ratio of the ic50 of blm in the absence versus the presence of bti delta-endotoxin, reached ca. 20 at 40 degrees c, suggesting that a ... | 1992 | 1380225 |
| vasopressin stimulation of vanadate-sensitive na+ transport by liver plasma membrane vesicles. evidence for regulation via phospholipase c and protein kinase c activities. | the rate of vanadate-sensitive 22na+ uptake by isolated liver membrane vesicles, reflecting transport by na+/k(+)-atpase, was measured to study the role played by phospholipase c and protein kinase c in the regulation of this process by vasopressin. na+ uptake was enhanced 2-3-fold by 100 nm [arg8]vasopressin and the hormone effect was mimicked by 0.1 microm inositol 1,4,5-trisphosphate as well as by 1.0 microm myo-inositol. the stimulation by vasopressin was potentiated by phosphatidylinositol- ... | 1992 | 1390861 |
| a method for the determination of bacterial spore dna content based on isotopic labelling, spore germination and diphenylamine assay; ploidy of spores of several bacillus species. | a reliable method for measuring the spore dna content, based on radioactive dna labelling, spore germination in absence of dna replication and diphenylamine assay, was developed. the accuracy of the method, within 10-15%, is adequate for determining the number of chromosomes per spore, provided that the genome size is known. b subtilis spores were shown to be invariably monogenomic, while those of larger bacilli bacillus megaterium, bacillus cereus and bacillus thuringiensis, often, if not invar ... | 1992 | 1391052 |
| serotyping of bacillus thuringiensis environmental isolates by extracellular heat-stable somatic antigens. | a total of 525 bacillus thuringiensis environmental isolates, belonging to the five flagellar (h) serovars (alesti, sotto, kenyae, aizawai, and morrisoni), were serotyped by extracellular heat-stable somatic antigens (hssas). the isolates belonging to a given h serovar were assigned to a single hssa serogroup at a high frequency, 87-100%. this indicates that the extent of hssa variation within a single h serovar is small in the field populations of these b. thuringiensis serovars. | 1992 | 1393835 |
| mode of replication, size and distribution of naturally occurring plasmids in bacillus thuringiensis. | cloned replication origin regions, derived from both small (4.9-7.5 mda) and large (43-60 mda) plasmids of bacillus thuringiensis subspecies kurstaki strains hd73 and hd263 were used as hybridization probes in a southern-blot analysis to assess both the size and horizontal distribution of native plasmid replicon groups among different subspecies of b. thuringiensis. in general, resident plasmids hybridizing to the replication origin regions derived from strains hd263 and hd73 were more commonly ... | 1992 | 1398029 |
| amphiphilic forms of butyrylcholinesterase in mucosal cells of rat intestine. | the properties of a cholinesterase from mucosal cells of rat intestine have been characterized. the enzyme was identified as butyrylcholinesterase because it was more sensitive to iso-ompa (ic50 = 1.0 x 10(-6) m) than to bw284c51 (ic50 = 5.5 x 10(-5) m) and was not inhibited by substrate excess. it displayed a higher affinity for acetylthiocholine than for butyrylthiocholine. a major molecular form was observed sedimenting at 5.9 s. two other minor molecular forms were identified as a hydrophili ... | 1992 | 1420201 |
| the study on phosphatidylinositol-specific phospholipase c from bacillus thuringiensis: synthesis of homogeneous substrates, substrate specificity and other properties. | the properties of phosphatidylinositol-specific phospholipase c (pi-plc) from bacillus thuringiensis were studied in detail. the enzyme was extremely thermostable in 0.1% bovine serum albumin and retained 73% of its activity at 100 degrees c for 10 min, while it was labile in the absence of albumin. the enzymatic activity was inhibited by hgcl2 or p-chloromercuriphenylsulfonic acid and restored by dithiothreitol. the kinetic parameters (km and vmax) of pi-plc were determined for the mixed micell ... | 1992 | 1423768 |
| isolation and sequence of a 2-kbp miniplasmid from bacillus thuringiensis var. kurstaki hd-3a3b: relationship with miniplasmids of other b. thuringiensis strains. | the miniplasmid profiles of 18 bacillus thuringiensis strains belonging to 8 different serotypes were determined using an alkaline hydrolysis method for isolation of low molecular mass plasmids. nearly all the strains contained covalently closed circular (ccc) dna species ranging from 2 to 5 species per strain and from 1.5 to 10.5 kbp in size (values corresponding to ccc forms). a 2-kbp plasmid from b. thuringiensis var. kurstaki hd-3a3b futura strain was used in southern hybridization experimen ... | 1992 | 1426990 |
| [inversion polymorphism in the malaria mosquito anopheles messeae. xi. the group effect of larval infection with bacillus thuringiensis subsp. israeliensis bacteria]. | genetic consequences of the group and individual infections of anopheles messeae larvae with bacteria bacillus thuringiensis subsp. israelensis (bti) were examined. the group effect of infections was manifested by increase in mortality and the speed-up of selection of chromosomal inversions resistant to bti. connection between the group and individual selections during the process of populations' adaptation is under discussion. | 1992 | 1427060 |
| efficacy of bacillus thuringiensis var. israelensis against larvae of the southern buffalo gnat, cnephia pecuarum (diptera: simuliidae), and the influence of water temperature. | susceptibility of southern buffalo gnat larvae to bacillus thuringiensis var. israelensis (b.t.i.) was studied during 1986-88. tests were conducted using vectobac 12as in a mini-gutter aquatic bioassay system. mini-gutter tests using a 4.5 ppm b.t.i. concentration and a 10 min exposure period confirmed a positive correlation between water temperature and b.t.i. effectiveness. significantly lower larval mortality occurred as water temperature decreased below 9 degrees c, indicating that proper ti ... | 1992 | 1431853 |
| fate of bacillus sphaericus and bacillus thuringiensis serovar israelensis in the aquatic environment. | bacillus sphaericus spores were suspended in bottles of filtered (0.45 microns) freshwater and seawater under various conditions of temperature, ph and salinity. heat resistant culturable counts (spores) slowly decreased with time. spores suspended in dialysis bags submerged in a freshwater pond or in flowing seawater underwent a more rapid drop in heat resistant spore counts than did spores held in bottles. thus, laboratory studies may overestimate spore longevity in the environment. spore sett ... | 1992 | 1431856 |
| reduction of mortality rates of bacillus thuringiensis var. israelensis aqueous suspensions due to freezing and thawing. | when studying the behavior (carry, dispersion, persistence) of bacillus thuringiensis var. israelensis (b.t.i.) formulations used in the treatment of rivers or streams for black fly control, a large number of samples containing small quantities of b.t.i. are required for proper analysis. freezing is a useful procedure to prevent enzymatic alteration or bacterial growth in samples before bioassays are to be performed. using aedes atropalpus neonate larvae, we studied the effect of freezing and th ... | 1992 | 1431857 |
| an episode of resistance to permethrin in larvae of simulium squamosum (diptera: simuliidae) from cameroon, after 3 1/2 years of control. | because of the biting nuisance from females of simulium squamosum, a 30 km section of the sanaga river (cameroon) was treated since 1987 with permethrin for the control of larval populations. in 1990, resistance to permethrin occurred in a small proportion of the larvae, with a resulting 2-4x increase of the lc95 for dead larvae (moribund larvae considered as live). in 1991, after a 6-month interruption of the treatments, susceptibility to permethrin returned to the initial level, and was simila ... | 1992 | 1431861 |
| [a trial of the possible joint use of mermithids and bacterial preparations for the control of mosquito larvae]. | the action of bacterial insecticides based on bacillus thuringiensis h-14 and b. sphaericus in a dose of 0.005-2 mg/l on the mermithids romanomermis iyengari, r. culicivorax and r. jingdeensis was studied. it was shown that though bacterial agents suppressed mermithid preparasite larvae density about 30-40%, the survivors might invade 100% of mosquito larvae. the viability and fertility of adult mermithids did not change under the influence of bactoculicide in doses 5-50 times higher than those ... | 1992 | 1435554 |
| [the optimization of a method for determining the insecticidal activity of bacterial preparations vis-à-vis mosquito larvae]. | | 1992 | 1435585 |
| evaluation of synergism among bacillus thuringiensis toxins. | a simple test for synergism among toxins is described and applied to previously reported data on independent and joint toxicities of insecticidal proteins from bacillus thuringiensis. the analysis shows synergism between a 27-kda (cyta) toxin and 130- or 65-kda (cryiv) toxins from b. thuringiensis subsp. israelensis against aedes aegypti larvae. no positive synergism between 130- and 65-kda toxins or among three cryia toxins tested against seven species of lepidoptera occurred. comparisons with ... | 1992 | 1444368 |
| [influence of carbon sources on the biological activity and morphology of bacillus thuringiensis parasporal crystals]. | the influence of the carbon source on biological activity and morphological properties of the parasporal crystals of bacillus thuringiensis subsp. kurstaki cultivated on three different media has been studied. biological activity of delta-endotoxins contained in crystals was tested according to their impact on insects and microorganisms. variations in carbon sources composition resulted in changes of biological activity and morphology of crystals, caused by alterations in synthesis rate of vario ... | 1992 | 1474939 |
| [comparative electron microscopic study of bacillus thuringiensis cells grown in a chemostat]. | it has been shown that the culture of bacillus thuringiensis subsp. gall. 69-6 dissociates into r- and s-variants in chemostat. although under some conditions the sporogenesis and the synthesis of s-variant toxin began two hours earlier than these processes in r-variant cells which were observed, respectively, after 10 or 12 hours from the beginning of the experiment, the intensities of sporogenesis and toxin production as well as the exit of spores and toxin excretion from cells were similar af ... | 1992 | 1474944 |
| characterization of two genes encoding bacillus thuringiensis insecticidal crystal proteins toxic to coleoptera species. | bacillus thuringiensis eg2838 and eg4961 are highly toxic to colorado potato beetle larvae, and only strain eg4961 is toxic to southern corn rootworm larvae. to investigate the cause of the different insecticidal activities of eg2838 and eg4961, cryiii-type genes toxic to coleopterans were cloned from each strain. the cryiiib gene, cloned as part of an 8.0-kb ecori fragment of eg2838 dna, encoded a crystal protein (cryiiib) of 74,237 da. the cryiiib2 gene, cloned as part of an 8.3-kb psti-asp718 ... | 1992 | 1476436 |
| increase in the resistance to the bacillus thuringiensis supernatant effect in a drosophila melanogaster wild type oregon r line. | we report here the genetical and x chromosome rdna molecular study of two drosophila melanogaster oregon r lines. these lines differ extensively in the degree of resistance of the females both to the lethal effect of an increased temperature and to that of bacillus thuringiensis beta-exotoxin, which is an inhibitor of the nucleolar rna polymerase. the 3b line, whose females are resistant, came from an oregon r population subjected over several generations to increased temperature, 28 degrees c o ... | 1992 | 1478886 |
| [molecular cloning and identification of 130kd mosquitocidal protein gene of bacillus thuringiensis var. israelensis (bti)]. | the location of 130kd mosquitocidal protein gene of bti 4q5 strain on its 75md plasmid was confirmed by southern hybridization using a 18-base oligonucleotide probe. the crystal protein containing the component of 130kd toxic protein was purified. the crystal protein exhibiting the mosquitocidal activity against larvae of aedes aegypti was shown by bioassay. the purified 75md plasmid dna of bti 4q5 strain was completely digested with hindiii restriction enzyme, ligated with the vector puc18 and ... | 1992 | 1481529 |
| [extracellular alkaline ribonuclease of bacillus thuringiensis var. subtoxicus]. | intraspecific selection of bacillus thuringiensis strains producing extracellular alkaline ribonucleases was carried out. subtoxicus subspecies with increased expression of the enzyme was detected. a method was developed to isolate preparative amounts of homogeneous extracellular rnase of b. thuringiensis var. subtoxicus. the physico-chemical and catalytic properties of the enzyme was studied and compared with extracellular rnases of others bacillus species. the conclusion about the structural a ... | 1992 | 1491677 |
| the occurrence of disporous bacillus thuringiensis cells. | ultrathin sections of sporulating bacillus thuringiensis were examined in a transmission electron microscope. less than 1% of the about 2,000 approximately sagittal sections of the bacterial cells examined contained two endospores per cell. this finding clarifies the majority of textbook and research reports (which tend to be ambiguous), contradicts several of the most recent textbook reports, and confirms three unillustrated textbook reports, in relation to the occurrence of disporous bacilli. ... | 1992 | 1497331 |
| properties of bacillus thuringiensis and its intracellular crystal proteins. | | 1992 | 1504588 |
| novel bacillus thuringiensis insecticidal crystal protein with a silent activity against coleopteran larvae. | a novel bacillus thuringiensis crystal protein with a silent activity against the colorado potato beetle is described. the crystal proteins are produced as bipyramidal crystals. these crystals contain a protein of 129 kda with a trypsin-resistant core fragment of 72 kda. neither a spore-crystal mixture nor in vitro-solubilized crystals are toxic to any of several lepidoptera and coleoptera species tested. in contrast, a trypsin-treated solution containing the 72-kda tryptic core fragment of the ... | 1992 | 1514800 |
| arabidopsis thaliana small subunit leader and transit peptide enhance the expression of bacillus thuringiensis proteins in transgenic plants. | the expression of the modified gene for a truncated form of the cryia(c) gene, encoding the insecticidal portion of the lepidopteran-active cryia(c) protein from bacillus thuringiensis var. kurstaki (b.t.k.) hd73, under control of the arabidopsis thaliana ribulose-1,5-bisphosphate carboxylase (rubisco) small subunit ats1a promoter with and without its associated transit peptide was analyzed in transgenic tobacco plants. examination of leaf tissue revealed that the ats1a promoter with its transit ... | 1992 | 1515613 |
| delivery of an accessory signal for cell activation by exogenous phosphatidylinositol-specific phospholipase c. | digestion of phosphatidylinositol (pi) or glycosylphosphatidylinositol (gpi) anchors of membrane proteins on the external cell surface with exogenous pi-specific phospholipase c (piplc) from bacillus thuringiensis was shown to transmit a signal into the thymocyte to modulate the tcr/cd3 complex-induced signal delivery for cell activation. this was demonstrated for very early protein tyrosine phosphorylation, early c-fos transcription and late dna synthesis. for this effect preincubation of the c ... | 1992 | 1535048 |
| translation enhancing properties of the 5'-leader of potato virus x genomic rna. | the double-stranded dna copy corresponding to the 5'-nontranslated alpha beta-leader of potato virus x (pvx) genomic rna (positions -3 to-85 according to aug initiator) was chemically synthesized and fused to the transcription plasmids containing three different reporter genes: neomycinphosphotransferase type ii (npt ii) gene, bacillus thuringiensis coleopteran-specific toxic protein gene and beta-glucuronidase (gus) gene. expression of the reporter genes in vitro and in plant protoplasts (in th ... | 1992 | 1537401 |
| membrane-bound aminopeptidase p from bovine lung. its purification, properties, and degradation of bradykinin. | the membrane-bound form of aminopeptidase p (aminoacylprolyl-peptide hydrolase) (ec 3.4.11.9) was purified to apparent homogeneity from bovine lung microsomes. the enzyme was solubilized using phosphatidylinositol-specific phospholipase c (bacillus thuringiensis), indicating that bovine lung amino-peptidase p is attached to membranes via a glycosylphosphatidylinositol anchor. the enzyme was purified 1900-fold with a yield of 25% by chromatography on decyl-agarose, omega-aminodecyl-agarose, a sec ... | 1992 | 1537867 |
| the insecticidal crystal protein cryia(c) from bacillus thuringiensis is highly toxic for heliothis armigera. | | 1992 | 1541846 |
| bacillus thuringiensis crystal protein: effect of chemical modification of the cysteine and lysine residues. | the 16 cysteine residues of reduced protoxin from bacillus thuringiensis subsp. kurstaki hd-73 can be quantitatively reacted with: (a) iodoacetic acid, to give carboxymethyl protoxin; (b) iodoacetamide, giving carbaminomethyl protoxin and (c) n-(beta-iodoethyl)trifluoroacetamide to give aminoethyl protoxin. the carboxymethyl derivative was found to be significantly more soluble at neutral ph values where both the native protoxin and the carbaminomethyl derivative exhibit low solubilities. at the ... | 1992 | 1541850 |
| nucleotide sequence of gene cryiiid encoding a novel coleopteran-active crystal protein from strain bti109p of bacillus thuringiensis subsp. kurstaki. | the nucleotide sequence of a novel insecticidal crystal protein(cry)-encoding gene from a bacillus thuringiensis serotype kurstaki isolate is described. the gene is related to the known coleopteran-active cryiii genes and encodes a cryiiid that is much more active against colorado potato beetle than other cryiii. | 1992 | 1544571 |
| biopesticides and resistance. | | 1992 | 1546283 |
| identification of an insecticidal crystal protein from bacillus thuringiensis dsir517 with significant sequence differences from previously described toxins. | the nucleotide (nt) sequence of a dna segment containing the majority of a gene cloned from bacillus thuringiensis dsir517 encoding a 130 kda insecticidal crystal protein has been determined. sequence analysis reveals an open reading frame (orf) of 3453 nt. the atg initiation codon, which is preceded by a potential ribosome-binding site sequence, was confirmed by n-terminal amino acid sequencing. the orf extends beyond the 3' terminus of the cloned fragment; however, the high degree of homology ... | 1992 | 1556556 |
| overproduction, purification and characterization of m.hinfi methyltransferase and its deletion mutant. | we have used the polymerase chain reaction to alter transcriptional and translational signals surrounding the hinfim gene [encoding m.hinfi methyltransferase (mtase)] so as to achieve overexpression in escherichia coli. the pcr-generated hinfim gene was subcloned in a high-expression vector under control of the hybrid trp-lac promoter. in addition, the positive retroregulator stem-loop sequence derived from the crystal protein-encoding gene of bacillus thuringiensis was inserted downstream from ... | 1992 | 1563635 |
| expression of the mosquitocidal toxins of bacillus sphaericus and bacillus thuringiensis subsp. israelensis by recombinant caulobacter crescentus, a vehicle for biological control of aquatic insect larvae. | in the quest for effective control of mosquitoes, attention has turned increasingly to strains of the bacteria bacillus sphaericus and bacillus thuringiensis subsp. israelensis, which produce potent toxins with specific mosquitocidal activities. however, sedimentation of the bacterial spores limits the duration of effective control after field application of these bacilli. we describe here the cloning of genes encoding the 51.4- and 41.9-kda toxins from b. sphaericus 2297, the 100-kda toxin from ... | 1992 | 1575492 |
| impact of the black fly (diptera: simuliidae) control agent bacillus thuringiensis var. israelensis on chironomids (diptera: chironomidae) and other nontarget insects: results of ten field trials. | except for moderate mortality among filter-feeding chironomids, rheotanytarsus spp., the results of 10 field trials with bacillus thuringiensis var. israelensis (b.t.i.) indicated a wide margin of safety to the chironomid community and other stream nontarget insects. mayflies, caddisflies and 2 other types of chironomids, i.e., tube-dwelling (chironominae) and surface-dwelling, caseless larvae (mix of chironominae, diamesinae, orthocladiinae, tanypodinae), did not appear to be affected. the susc ... | 1992 | 1583485 |
| isolation of mosquito-toxic bacteria from mosquito-breeding sites in kenya. | a large number of source materials were collected for isolating entomopathogenic bacteria from larval mosquito habitats in kirinyaga district, kenya. mosquito-toxic bacteria were included among the numerous types of microorganisms isolated from the habitats. the pathogenic isolates shared common structural characteristics; they were gram-positive, spore-forming bacilli that produced parasporal inclusions conferring broad-spectrum larvicidal activity against anopheles, culex and aedes mosquitoes. ... | 1992 | 1583497 |
| identification and characterization of a novel bacillus thuringiensis delta-endotoxin entomocidal to coleopteran and lepidopteran larvae. | a new class of bacillus thuringiensis delta-endotoxins, or insecticidal control proteins (icps), is defined by an apparently cryptic protein with a unique primary structure and novel entomocidal specificity for certain coleopteran and lepidopteran species. the discovery of a new group of icps will extend the use of this natural insecticide in integrated pest-management systems. | 1992 | 1588820 |
| comparative toxicity of the hd-1 and nrd-12 strains of bacillus thuringiensis subsp. kurstaki to defoliating forest lepidoptera. | insecticidal activities of sporulated cultures of the hd-1 and nrd-12 strains of bacillus thuringiensis subsp. kurstaki were compared against four species of defoliating forest lepidopterans in diet-incorporation assays. there was no difference in lc50 between the two strains to larvae of spruce budworm (choristoneura fumiferana), gypsy moth (lymantria dispar), eastern hemlock looper (lambdina fiscellaria fiscellaria), and whitemarked tussock moth (orgyia leucostigma), whether expressed as total ... | 1992 | 1607666 |
| digestion of bacillus thuringiensis var. israelensis spores by larvae of aedes aegypti. | the larvicidal activity of bacillus thuringiensis var. israelensis against mosquitoes and the blackfly is included in parasporal crystalline bodies which are produced during sporulation. following ingestion, the crystals are solubilized in the larval midgut and induce death within a short time; the spores germinate in the dead larvae and complete a growth cycle. the fate of the spores in surviving live larvae was elucidated by using a nonlarvicidal b. thuringiensis var. israelensis mutant. when ... | 1992 | 1607667 |
| a novel bioassay system for evaluating the toxicity of bacillus thuringiensis israelensis against mosquito larvae. | a bioassay system employing acutely toxic concentrations of a spore-crystal mixture of bacillus thuringiensis subspecies israelensis against fourth instar larvae of aedes aegypti (l.) is described. individual larvae are separately exposed to toxin in glass-lined miniature wells or scintillation vials. this method is free from the deaths due to predation among larvae. such larval deaths are commonly encountered in bioassay groups of 25 larvae as currently specified in the world health organizatio ... | 1992 | 1607671 |
| properties of a 72-kilodalton mosquitocidal protein from bacillus thuringiensis subsp. morrisoni pg-14 expressed in b. thuringiensis subsp. kurstaki by using the shuttle vector pht3101. | the mosquitocidal properties of bacillus thuringiensis subsp. israelensis and b. thuringiensis subsp. morrisoni pg-14 are attributable to protein inclusions grouped together within a parasporal body. in both of these strains, the mosquitocidal activity resides in proteins with molecular masses of 27, 72, 128, and 135 kda. in an attempt to determine the toxicity of each protein, the shuttle vector pht3101 was used to express the cryivd gene (encoding the 72-kda cryivd protein) from b. thuringiens ... | 1992 | 1610175 |
| insecticidal properties of a crystal protein gene product isolated from bacillus thuringiensis subsp. kenyae. | a protoxin gene, localized to a high-molecular-weight plasmid from bacillus thuringiensis subsp. kenyae, was cloned on a 19-kb bamhi dna fragment into escherichia coli. characterization of the gene revealed it to be a member of the cryie toxin subclass which has been reported to be as toxic as the cryic subclass to larvae from spodoptera exigua in assays with crude e. coli extracts. to directly test the purified recombinant gene product, the gene was subcloned as a 4.8-kb fragment into an expres ... | 1992 | 1610185 |
| lethal and sublethal effects of bacillus thuringiensis var. kurstaki on aquatic insects in laboratory bioassays and outdoor stream channels. | | 1992 | 1611248 |
| toxicity of bacillus thuringiensis against damalinia ovis (phthiraptera:mallophaga). | | 1992 | 1619297 |
| cloning and expression of the cryivd gene of bacillus thuringiensis subsp. israelensis in the cyanobacterium agmenellum quadruplicatum pr-6 and its resulting larvicidal activity. | a mosquitocidal cyanobacterium has been developed by introducing the mosquito-toxic cryivd gene from bacillus thuringiensis subsp. israelensis into the unicellular cyanobacterium agmenellum quadruplicatum pr-6 (synechococcus sp. strain pcc 7002). the cryivd gene was introduced into the cyanobacterium on a derivative of the pr-6 expression vector paqe19 delta sal in which the cryivd gene was translationally fused to the initial coding sequence of the highly expressed pr-6 cpcb gene. coomassie blu ... | 1992 | 1622235 |
| plasma-membrane-intercalated heparan sulphate proteoglycans in an osteogenic cell line (umr 106-01 bsp). | the heparan sulphate (hs) proteoglycans associated with the cell layer of a rat osteosarcoma cell line [umr 106-01 (bsp)] were compared with similar cell-associated proteoglycans from other cells, and their interaction with the plasma membrane was studied. hs proteoglycans were metabolically labelled by incubation of cell cultures with [3h]glucosamine or [3h]leucine and [35s]sulphate. hs proteoglycan core protein preparation generated by heparitinase digestion of the major species from umr 106-0 ... | 1992 | 1637308 |
| biopesticides and resistance. | | 1992 | 1637378 |
| identification of phosphatidylinositol-specific phospholipase c activity in listeria monocytogenes: a novel type of virulence factor? | a phospholipase c which cleaves phosphatidylinositol and glycosylphosphatidylinositol (gpi) anchors was identified in listeria monocytogenes. this 36 kda protein is encoded by the gene plca, and is homologous to the bacillus cereus, bacillus thuringiensis and eukaryotic phosphatidylinositol-specific phospholipases c (pi-plc). expression of the plca gene in escherichia coli correlates with the appearance of pi-plc activity in the cells. in listeria monocytogenes, the activity is secreted to the c ... | 1991 | 1645839 |
| phosphatidylinositol-specific phospholipases c from bacillus cereus and bacillus thuringiensis. | | 1991 | 1646937 |
| is231a from bacillus thuringiensis is functional in escherichia coli: transposition and insertion specificity. | a kanamycin resistance gene was introduced within the insertion sequence is231a from bacillus thuringiensis, and transposition of the element was demonstrated in escherichia coli. dna sequencing at the target sites showed that is231a transposition results in direct repeats of variable lengths (10, 11, and 12 bp). these target sequences resemble the terminal inverted repeats of the transposon tn4430, which are the preferred natural insertion sites of is231 in b. thuringiensis. | 1991 | 1648561 |
| sequence of an operon containing a novel delta-endotoxin gene from bacillus thuringiensis. | an insect larval toxin designated cryii is produced by several subspecies of bacillus thuringiensis and differs from the other major delta-endotoxins in these bacteria in its size, toxicity profile and presence as part of an operon with three open reading frames (orf). such an operon from a novel b. thuringiensis isolate has been cloned and differs from one previously characterized in the following ways: (a) the size and number of amino acid repeats in one of the orfs; (b) the smaller size of th ... | 1991 | 1651878 |
| a study of human erythrocyte acetylcholinesterase inhibition by chlorpromazine. | membrane-bound acetylcholinesterase (ache) from the human erythrocyte is inhibited by chlorpromazine (cpz) in a concentration range within this amphiphilic drug has been demonstrated to interact with erythrocyte membranes, causing a large spectrum of physical and structural effects; membrane solubilization with 0.5% triton x-100 results in a complete loss of cpz inhibitory potency. although these observations might suggest a role of membrane lipid environment in mediating human erythrocyte ache ... | 1991 | 1654884 |
| cloning and analysis of delta-endotoxin genes from bacillus thuringiensis subsp. alesti. | bacillus thuringiensis subsp. alesti produced only cryia(b)-type protoxins, and three cryia(b) genes were cloned. one was cryptic because of an alteration near the 5' end, and the other two were very similar to each other. the protoxin encoded by one of the latter genes differed from other cryia(b) protoxins in its greater stability and relative toxicity for two members of the order lepidoptera. | 1991 | 1655719 |
| crystal structure of insecticidal delta-endotoxin from bacillus thuringiensis at 2.5 a resolution. | the structure of the delta-endotoxin from bacillus thuringiensis subsp. tenebrionis that is specifically toxic to coleoptera insects (beetle toxin) has been determined at 2.5 a resolution. it comprises three domains which are, from the n- to c-termini, a seven-helix bundle, a three-sheet domain, and a beta sandwich. the core of the molecule encompassing all the domain interfaces is built from conserved sequence segments of the active delta-endotoxins. therefore the structure represents the gener ... | 1991 | 1658659 |
| n-acetyl galactosamine is part of the receptor in insect gut epithelia that recognizes an insecticidal protein from bacillus thuringiensis. | proteins synthesized by the bacterium bacillus thuringiensis are potent insecticides. when ingested by susceptible larvae they rapidly lyse epithelial cells lining the midgut. in vitro the toxins lyse certain insect cell lines and show saturable, high-affinity binding to brush-border membrane vesicles (bbmvs) prepared from insect midguts. we observed that the sugar n-acetyl galactosamine (galnac) specifically decreased the cytolytic activity of a cryia(c) toxin towards choristoneura fumiferana c ... | 1991 | 1658805 |
| nucleotide sequence of a novel delta-endotoxin gene cryig of bacillus thuringiensis ssp. galleriae. | a gene cryig coding for entomocidal protein delta-endotoxin of bacillus thuringiensis ssp. galleriae str. 11-67 named cryig has been cloned and sequenced (embl accession number x58120). the deduced amino acid sequence that contains 1156 amino acid residues shows only 28% of identical residues, when compared with other delta-endotoxins of the cryi family. the extent of identity is substantially higher for some regions of the sequence ('conserved blocks'), that presumably bear important structural ... | 1991 | 1660003 |
| inhibition of potassium-gradient-driven phenylalanine uptake in larval lymantria dispar midgut by two bacillus thuringiensis delta-endotoxins correlates with the activity of the toxins as gypsy moth larvicides. | | 1991 | 1661774 |
| identification and characterization of heliothis virescens midgut membrane proteins binding bacillus thuringiensis delta-endotoxins. | to investigate the specificity of bacillus thuringiensis var. kurstaki strain hd1 insecticidal crystal proteins (icp), we used membrane preparations obtained from the midgut of heliothis virescens larvae to perform separate ligand-blot experiments with the three activated cryia toxins. the cryia(a) and the cryia(b) toxins bind the same 170-kda protein, but most likely at two different binding sites. the cryia(c) toxin binds two proteins of molecular masses 140 kda and 120 kda. we also demonstrat ... | 1991 | 1662137 |
| construction of cloning vectors for bacillus thuringiensis. | the replication region of the bacillus thuringiensis plasmid, pht1030, was treated with hydroxylamine. various copy-number mutants were selected and subsequently used to construct shuttle vectors with multiple cloning sites. these recombinant plasmids are very stable and allowed the cloning of a delta-endotoxin-encoding gene in b. thuringiensis. comparison between gene expression level and vector copy-number indicated that a plateau in delta-endotoxin production is reached with a copy-number of ... | 1991 | 1662180 |
| differential inhibition by bacillus thuringiensis delta endotoxin of leucine and aspartic acid uptake into bbmv from midgut of manduca sexta. | pre-incubation of brush border membrane vesicles (bbmv) isolated from the midgut of manduca sexta with activated bacillus thuringiensis delta endotoxin for a short period resulted in differential inhibition of k(+)-dependent transport of leucine relative to the effect on k(+)-dependent transport of aspartic acid. the difference in i1/2 (5 fold greater for aspartic acid than for leucine) is interpreted as the result of enhanced binding of the b. thuringiensis delta endotoxin to the leucine transp ... | 1991 | 1662492 |
| insect resistance of transgenic tobacco plants expressing delta-endotoxin gene of bacillus thuringiensis. | the initiative b.thuringiensis delta-endotoxin (bt toxin) gene clones th12 and th48 contain two different classes of homologous genes, the 5.3 kb class and 6.6 kb class, respectively. bt toxin genes of both classes, modified at the 5'-end and truncated at the 3'-end, can still be expressed to produce the insecticidal, truncated toxin proteins in e. coli. the modified bt toxin genes were inserted into the plant binary expression vector pbin 437 (a derivative plasmid of pbin 19) and were transferr ... | 1991 | 1663400 |
| the c-terminal domain of the toxic fragment of a bacillus thuringiensis crystal protein determines receptor binding. | the insecticidal crystal proteins of bacillus thuringiensis show a high degree of specificity. in vitro binding studies with several crystal proteins demonstrated a correlation between toxicity and binding to receptors of larval midgut epithelial cells. in order to study the domain-function relationships of the toxic fragment, hybrid crystal proteins based on cryia(b) and cryic were constructed. two out of 11 hybrid proteins constructed exhibited insecticidal activity. both dispalyed an insectic ... | 1991 | 1664021 |
| stability of the delta-endotoxin gene from bacillus thuringiensis subsp. kurstaki in a recombinant strain of clavibacter xyli subsp. cynodontis. | deletion of chromosomally inserted gene sequences from clavibacter xyli subsp. cynodontis, a xylem-inhabiting endophyte, was studied in vitro and in planta. we found that nonreplicating plasmid pcg610, which conferred resistance to kanamycin and tetracycline and contained segments of c. xyli subsp. cynodontis genomic dna, integrated into a homologous sequence in the bacterial chromosome. in addition, pcg610 contains two copies of the gene encoding the cryia(c) insecticidal protein of bacillus th ... | 1991 | 1664710 |
| [search for producers of restriction endonucleases with a given specificity]. | six site-specific restriction endonucleases were isolated from bacillus thuringiensis strains chosen of 58 strains ought purposefully for production of restriction enzymes. all six strains produce isoschisomers of sau3a. | 1991 | 1667028 |
| fed-batch fermentation studies with bacillus thuringiensis h-14 synthesising endotoxin. | cell yield and toxicity of b. thuringiensis h-14 was improved markedly by adopting a simple fed-batch fermentation technique based on controlling glucose concentration. maintenance of steady glucose concentration (0.3-0.5%) in the culture medium was achieved by the continuous addition of concentrated glucose solution. addition of glucose at 3 g/hr/l of culture starting from 3rd hr till 16th hr of fermentation was found to yield cell densities of 80 g/l (wet weight) which represented a nearly 3-f ... | 1991 | 1667779 |
| high-level expression in escherichia coli and rapid purification of phosphatidylinositol-specific phospholipase c from bacillus cereus and bacillus thuringiensis. | the construction of four vectors for high-level expression in escherichia coli of the phosphatidylinositol-specific phospholipase c from bacillus cereus or bacillus thuringiensis is described. in all constructs the coding sequence for the mature phospholipase is precisely fused to the e. coli heat-stable enterotoxin ii signal sequence for targeting of the protein to the periplasm. in one set of plasmids expression of the b. cereus or b. thuringiensis enzyme is under control of the e. coli alkali ... | 1991 | 1668269 |
| [bacillus thuringiensis: biological characteristics and production perspectives]. | in this paper the potential activity of bacillus thuringiensis as insecticide is reviewed. it is presented recent knowledges of its metabolism, production system and the rinetic constants already reported finally the possibilities for production in batches or continuous culture is discussed in order to improve the productivity and economical aspects. | 1991 | 1670264 |
| deletion by in vivo recombination shows that the 28-kilodalton cytolytic polypeptide from bacillus thuringiensis subsp. israelensis is not essential for mosquitocidal activity. | the cyta gene encoding the 28-kda polypeptide of bacillus thuringiensis subsp. israelensis crystals was disrupted in the 72-mda resident plasmid by in vivo recombination, thus indicating that homologous recombination occurs in b. thuringiensis. the absence of the 28-kda protein in b. thuringiensis did not affect the crystallization of the other toxic components of the parasporal body (68-, 125-, and 135-kda polypeptides). the absence of the 28-kda protein abolished the hemolytic activity of b. t ... | 1991 | 1675212 |
| effect of corn-steep liquor on growth and mosquito larvicidal activity of bacillus thuringiensis var israelensis de barjac 1978 and b. sphaericus neide 1904. | influence of corn steep liquor on the cell yield and toxicity of three strains of b. thuringiensis var israelensis and two strains of b. sphaericus was studied and compared with peptone-yeast extract using a laboratory fermentor. large increase in the cell yield of all the three strains of b. thuringiensis var israelensis was observed when cornsteep liquor was used as the sole nitrogen source. significant increase in toxicity was also observed in b. thuringiensis var israelensis strains b17 and ... | 1991 | 1678365 |
| bacillus sphaericus as a mosquito pathogen: properties of the organism and its toxins. | in the course of sporulation, bacillus sphaericus produces an inclusion body which is toxic to a variety of mosquito larvae. in this review we discuss the general biology of this species and concentrate on the genetics and physiology of toxin production and its processing in the midgut of the larval host. the larvicide of b. sphaericus is unique in that it consists of two proteins of 51 and 42 kda, both of which are required for toxicity to mosquito larvae. there is a low level of sequence simil ... | 1991 | 1682792 |
| subspecies-specific haemagglutination patterns of fimbriated bacillus thuringiensis spores. | electron microscopy revealed fimbrial appendages (pili) of three types on the surface of bacillus thuringiensis spores. fimbriated spores induced mannose-resistant agglutination of rat, guinea pig and/or chicken red blood cells. each haemagglutination pattern correlated with the subspecies of a given b. thuringiensis strain, rather than with its flagellar serotype. fimbriation and haemagglutination patterns of b. thuringiensis spores are considered to be of possible taxonomic value. | 1991 | 1686005 |
| phorbol esters increase synthesis of decay-accelerating factor, a phosphatidylinositol-anchored surface protein, in human endothelial cells. | a number of cell-surface proteins are anchored by a phosphatidylinositol (pi)-glycan moiety. these proteins can be released by pi-specific phospholipases c (pi-plc). decay-accelerating factor (daf) is such a cell-surface protein that protects cells from inadvertent complement attack by binding to and inactivating c3 and c5 convertases. we have studied the regulation of daf synthesis in human umbilical vein endothelial cells (huvec), a cell that has the highest level of surface daf among those hu ... | 1990 | 1688581 |
| at least one bacillus thuringiensis toxin forms ion-selective pores in membranes. | | 1990 | 1690468 |
| field trial of abate and teknar for simulium (diptera: simuliidae) control in india. | simulium breeding was eliminated in a river up to 30 km with 0.1 ppm abate (temephos) for 30 min exposure. teknar (bacillus thuringiensis var. israelensis) at 10 ppm for 10 min exposure resulted in 98.4% and 87.9% reduction up to 20 m in 2 sections of a small stream. | 1990 | 1691272 |
| extra cellular hydrolytic enzyme secretion in bacillus thuringiensis h14 & b. sphaericus & their significance in media design. | level of extracellular proteolytic and amylolytic enzyme production was determined to assess the ability of these strains in utilizing complex carbon and nitrogen sources. protease secretion reached maximum at around 12th h of growth in case of all the three b. thuringiensis strains and declined sharply thereafter. in b. sphaericus strains the protease level gradually increased and reached maximum at around 24th h of growth. amylase activity was not detectable in the culture supernatants of b. s ... | 1990 | 1693135 |
| [antigenic structure of endotoxins from bacillus thuringiensis]. | the proteins of parasporal crystals of 9 strains of entomopathogenic bacteria of the bacillus thuringiensis group of different h-serotypes were studied by different methods. electrophoresis showed that crystals from the bacteria of 1, 3, 4, 5, 8, and 10 serotypes contained 1-2 proteins with a molecular weight of 130-145 kd and an additional fraction with a molecular weight of 55-120 kd. double-radial immunodiffusion revealed that the crystals of all the serotypes studied are immunologically rela ... | 1990 | 1693428 |