Showing papers on "Bacillus thuringiensis published in 1976"
TL;DR: Mutants of Bacillus thuringiensis lacking either beta-exotoxin or gamma-endotoxin were compared for their virulence using pupae of a giant silk moth to imply that, in the system used, neither the beta- Exotoxin nor the gamma- endotoxin and the sporeforming ability are of importance for virulence.
Abstract: Mutants of Bacillus thuringiensis lacking either beta-exotoxin or gamma-endotoxin were compared for their virulence using pupae of a giant silk moth. Known doses of viable log-phase bacteria were injected, and the response was followed as the number of viable bacteria in the hemolymph. The results obtained imply that, in the system used, neither the beta-exotoxin nor the gamma-endotoxin and the sporeforming ability are of importance for virulence. Results with sterile culture filtrate from B. thuringiensis have given evidence for the production of two inhibitors, A and B, which interfere with the humoral defense system in pupae of Hyalophora cecropia. Inhibitor A, which blocked the lysis of Escherichia coli,was precipitated by trichloroacetic acid and sensitive to heating. Inhibitor B, which blocked the killing of Bacillus cereus, was soluble in trichloroacetic acid and resistant to 90 degrees C for 5 min. Both inhibitors are believed to contribute to the insecticidal nature of B. thuringiensis.
71 citations
TL;DR: Cells from three insect cell lines responded to the enzyme-digested delta endotoxin of Bacillus thuringiensis with swelling, lysis, and vesicle formation and Cytoxic activity was neutralized by specific antiserum to the endotoxin.
Abstract: Cells from three insect cell lines responded to the enzyme-digested delta endotoxin of Bacillus thuringiensis with swelling, lysis, and vesicle formation. Sufficient toxin was taken up in 1 minute to cause half-maximal cell damage. Cytoxic activity was neutralized by specific antiserum to the endotoxin.
57 citations
TL;DR: The results suggest than an observed gross loss of potency of this serotype in beehives is more likely to be due to death of spores than to deterioration of crystals, and the reaction of G. mellonella to serotype V is nearest to that of a type 3 host species.
49 citations
TL;DR: Results indicated that B. thuringiensis δ-endotoxin could act as an uncoupler of oxidative phosphorylation and lead to metabolic imbalance and possible cell death in mitochondria isolated from Bombyx mori midgut epithelium.
40 citations
35 citations
TL;DR: In laboratory studies, an aqueous suspension of a commercial wettable powder formulation of Bacillus thuringiensis var.
Abstract: In laboratory studies, an aqueous suspension of a commercial wettable powder formulation of Bacillus thuringiensis var. kurstaki (strain HD-1) containing at least 25 billion viable spores/g and 16000 International Units of Potency (Trichoplusia ni (Hubner))/mg prevented infestations of Indian meal moths, Plodia interpunctella (Hubner), and almond moths, Cadra cautella (Walker), in corn and wheat at a dose of ca. 120 mg of formulation/kg of grain. Treatment of a 100-mm-deep surface layer was more effective than treatments 33 or 67 mm deep and as effective as treatment of the entire grain mass Lack of uniformity in applying B. thuringiensis to the grain kernels caused a small decrease in effectiveness. Dust and bait formulations at about the same doses were as effective as the suspension, but the bait was undesirable because it supported the development of beetle larvae. The formulation was less effective in controlling the Angoumois grain moth, Sitotroga cerealella (Olivier): doses that gave complete control of the Indian meal moth and the almond moth reduced emergence of adult Angoumois grain moths by only about one-third.
23 citations
TL;DR: The activity of 2 microbial insecticides on small samples of wheat did not decrease appreciably during a year of storage in a farm bin of wheat in which temperatures ranged from −19° to 48°C.
Abstract: The activity of 2 microbial insecticides on small samples of wheat did not decrease appreciably during a year of storage in a farm bin of wheat in which temperatures ranged from −19° to 48°C. Bacillus thuringiensis var. kurstaki spore viability decreased ca. 25%, primarily during the summer months. In the laboratory, insecticidal activity of the granulosis virus of Plodia interpunctella (Hubner) and B. thuringiensis decreased to ca. 10 and 85% of the original levels, respectively, when treated wheat was stored at a constant temperature of 42.0°C for 42 weeks. The viability of B. thuringiensis spores on wheat decreased rapidly immediately after application and at a lower rate throughout the laboratory-storage period. The decreases were directly proportional to storage temperature.
21 citations
TL;DR: The microbial insecticide Bacillus thuringiensis Berliner and the parasitoid Apanteles melanoscelus Ratzeburg were evaluated against the gypsy moth, Porthetria dispar, infesting an oak forest in Pennsylvania and larval populations consistently reduced at the 3 population densities tested.
Abstract: The microbial insecticide Bacillus thuringiensis Berliner and the parasitoid Apanteles melanoscelus Ratzeburg were evaluated against the gypsy moth, Porthetria dispar (L.), infesting an oak forest in Pennsylvania. The biotic agents were compared individually and in combination. In general, where only the parasitoid was released, foliage protection and population reduction was not significantly different from the untreated areas. Aerial application of B. thuringiensis provided foliage protection and population reduction when compared with the control or where only parasitoids were released. When the parasitoid was released in areas treated with B. thuringiensis additional foliage protection was attained. Only where the parasitoid was used with B. thuringiensis were larval populations consistently reduced at the 3 population densities tested.
21 citations
TL;DR: The thin-sectioned spore of Bacillin thuringiensis resembles that of Bacillus cereus in fine structure and is structured differently from the parasporal crystal outside the exosporium.
Abstract: The thin-sectioned spore of Bacillus thuringiensis resembles that of Bacillus cereus in fine structure. Planar inclusions occur between the exosporium and spore coat and are structured differently from the parasporal crystal outside the exosporium.
20 citations
17 citations
TL;DR: Bacteria isolated from egg masses of the European corn borer, Ostrinia nubilalis, were identified by biochemical and other definitive tests as Bacillus thuringiensis var.
TL;DR: Bacillus thuringiensis Berliner in combination with 0.1, 0.5, 1.5 and 2% boric acid caused 100% mortality of the tobacco caterpillar, Spodoptera litura (F), irrespective of instar, in a much shorter period than with boric Acid or the pathogen alone.
Abstract: Bacillus thuringiensis Berliner in combination with 0.1, 0.5, 1.0, 1.5 and 2% boric acid caused 100% mortality of the tobacco caterpillar,Spodoptera litura (F.), irrespective of instar, in a much shorter period (1.77 to 3.61 days) than with boric acid or the pathogen alone. The toxicity ofB. thuringiensis in combination with dicrotophos at 0.02 and 0.04%, with fenitrothion at 0.025 and 0.05%, or with dichlorvos at 0.01 and 0.05%, was enhanced.
TL;DR: Thuringiensin A, an exotoxin from Bacillus thuringiensis, a constituent of the microbial insecticide thuricide has been found to inhibit mitotic spindle, condense and scatter chromosomes and may therefore be a promizing tool in future cell biological studies.
Abstract: Thuringiensin A, an exotoxin fromBacillus thuringiensis, a constituent of the microbial insecticide thuricide has been found to inhibit mitotic spindle, condense and scatter chromosomes. It may therefore be a promizing tool in future cell biological studies.
Journal Article•
TL;DR: Strains of Bacillus thuringiensis were shown to hydrolyse various forms of chitin around growing colonies on a solid medium in conditions of submerged cultivation on a medium containing demineralized crab shells.
Abstract: Strains of Bacillus thuringiensis were shown to hydrolyse various forms of chitin around growing colonies on a solid medium. In conditions of submerged cultivation on a medium containing demineralized crab shells, Bac. thuringiensis var. caucasicus INMI Arm. 837 manifests the chitinolytic activity at the beginning of the stationary growth phase. The activity of chitinase which is of a constitutive nature increases when the bacterium is cultivated at pH 7.2. The maximum rate of hydrolysis of colloid chitin by chitinase prepared from the cultural broth is displayed at pH 8.0 and 60 degrees C.
01 Jan 1976
TL;DR: Bioassays of the bacteria on first-instar larvae and egg masses showed that Bacillus thuringiensis var.
Journal Article•
CSAV1
TL;DR: The efficacy of bacterial preparations depends, however, on the environmental temperature occurring within the first week after the application, and the adequate temperature is the primary deciding for the feeding activity of caterpillars and for the virulence of the preparations.
Abstract: The field persistence and efficacy of Bacillus thuringiensis formulations
The persistence of spores ofBacillus thuringiensis (commercial formulation Dipel and Bathurin) on oak leaves under different climatic condition in field trials was determined. The killing activity of these preparations against wintermothOperophthera brumata and green oak tortrix Tortrix viridana was parallely tested. Within the first week after the application of bacterial preparations the viable spore count on leaves was reduced of two up to three orders. The efficacy of bacterial preparations depends, however, on the environmental temperature occurring within the first week after the application. The adequate temperature is the primary deciding for the feeding activity of caterpillars and for the virulence of the preparations. For aerial application doses of 0.5 to 1.0 kg of the preparation in 50 100 l of water per one ha were sufficient. In the contrary, Dipel WP in oil suspension was unsufficient for aerial application because of mechanical blocking of the nozzles. The optimal time for the procedure was the first week of May in our climatic conditions.
Patent•
22 Nov 1976
TL;DR: In this article, a method for the biosynthesis of a microbial insecticide containing spores and crystalline endotoxin, in which a Bacillus thuringiensis microorganism is cultivated in a nutrient medium under formation of spores in such a way that the early lysis of the cells caused in the course of the submerged cultivation by the ventilation prior to the end of the forming of spores is prevented, is described.
Abstract: A method for the biosynthesis of a microbial insecticide containing spores and crystalline endotoxin, in which a Bacillus thuringiensis microorganism is cultivated in a nutrient medium under formation of spores in such a way that the early lysis of the cells caused in the course of the submerged cultivation by the ventilation prior to the end of the formation of spores is prevented, is described.
TL;DR: Results based on hybridization-competition experiments suggested that the mRNA coding for the parasporal crystal, a specific sporulation protein, might be transcribed preferentially by the form I and the form II of the sporulation enzyme.
TL;DR: Two sesquiterpene lactones, hymenovin and tenulin, were tested for their effect on growth of two strains of Bacillus thuringiensis, resulting in production of several variant strains.
Abstract: Two sesquiterpene lactones, hymenovin and tenulin, were tested for their effect on growth of two strains of Bacillus thuringiensis. Growth of both strains was 98% inhibited by 0.6 mg of tenulin per ml, but only 15 to 20% was inhibited by the same level of hymenovin. Hymenovin appeared to have a mutagenic effect on B. thuringiensis cultures resulting in production of several variant strains. Some of the variant strains had lost their ability to form spores and crystals. Hymenovin also induced B. thuringiensis to produce significant levels of bacteriophage. All variant strains were as susceptible to phage as the parent strain. Although the bactericidal activity of tenulin was two times as great as of hymenovin, tenulin did not appear to have a mutagenic effect on the bacteria.
25 Jun 1976
TL;DR: The results show that the action of the antitumor protein appears to alter the cellular permeability of the tumor cells.
Abstract: A purified antitumor protein from the proteinaceous crystal of Bacillus thuringiensis subsp. thuringiensis inhibits the growth of Yoshida ascites sarcoma both in vivo and in vitro. Exogenous respiration of the tumor cells was unaffected by the protein at a concentration as high as 500 µg/ml. The antitumor protein inhibits the uptake and incorporation of labeled precursors into macromolecules. However, the ratio of incorporation over uptake is not affected by the protein. Further, the protein brings about the leakage of 260-nm-absorbing material, proteins, and 32P-labeled cellular constituents from the Yoshida ascites sarcoma cells. The results show that the action of the antitumor protein appears to alter the cellular permeability of the tumor cells.
TL;DR: Bacteriophage CP-51, a transducing phage of Bacilli cereus was able to replicate on all eight varieties of Bacillus thuringiensis tested, and the plaque size was uniform for each strain regardless of plaque type.
Abstract: Bacteriophage CP-51, a transducing phage of Bacillus cereus was able to replicate on all eight varieties of Bacillus thuringiensis tested. Three general plaque types were observed on each strain although one type predominated on each strain. The plaque size was uniform for each strain regardless of plaque type. The bacterial strain used as source of the phage had no effect on plaque type or size found on any host strain. CP-51 was stable in infected spores of B. thuringiensis var. kurstaki for at least 305 days even though most of the spores had lost refractility. Free phage particles produced in B. thuringiensis were stable for at least 10 days in broth at 14 °C but were very unstable at 4 °C.