Showing papers on "Bacillus thuringiensis published in 1971"
TL;DR: The spore-δ-endotoxin complex of Bacillus thuringiensis was recovered from beers produced by 16 isolates and the activity of preparations of B. thuriengiensis could not be predicted from the serotype.
60 citations
TL;DR: Under given experimental conditions, a reproducible sequence of biochemical events can be measured during sporulation in Bacillus thuringiensis and it is suggested that the crystal protein is synthesized at the time of appearance of crystal antigens and assembled on the exosporium.
Abstract: Under given experimental conditions, a reproducible sequence of biochemical events can be measured during sporulation in Bacillus thuringiensis. Electron microscope studies reveal that, during its formation, the crystalline inclusion of Bacillus thuringiensis is closely associated with the exosporium. This association persists through several serial sections and can also be demonstrated in a mutant strain which is biochemically blocked soon after crystal formation.
Two asporogenic crystalliferous strains produce a toxin active on larvae of Plutella maculipennis whereas two sporogenic, acrystalliferous strains are not toxic.
Data from immunological assays and from pulse-chase and label-chase experiments with [14C]leucine indicate that the crystal protein is synthesized at the time of appearance of crystal antigens. It is suggested that the crystal is synthesized and assembled on the exosporium.
54 citations
TL;DR: Uptake of glucose-14C by guts of the silkworm Bombyx mori was stimulated within 1 min after administration of Bacillus thuringiensis δ-endotoxin, and general metabolic breakdown of the gut epithelium appears to occur between 10 and 20 min after Administration of the toxin.
38 citations
38 citations
32 citations
TL;DR: Differences in amino-acid composition and biological activity exclude the possibility that the larger polypeptide chain is a dimer of the smaller one, and the full toxicity of the unfractionated protein to larvae of Pieris brassicae is retained by fraction A, whereas fraction B is non-toxic.
Abstract: The crystal protein of Bacillus thuringiensis var. tolworthi has been separated into two polypeptide chains having molecular weights of 55000 (A) and 120000 (B). The ratio of A to B in the crystal appears to be 2:1 on a molar basis. Differences in amino-acid composition and biological activity exclude the possibility that the larger polypeptide chain is a dimer of the smaller one. The full toxicity of the unfractionated protein to larvae of Pieris brassicae is retained by fraction A, whereas fraction B is non-toxic.
29 citations
TL;DR: Results showed that the fraction produced high mortality in adult mites and eggs and immature states, and the test material was toxic for at least 45 days after application.
26 citations
19 citations
18 citations
TL;DR: There was excellent agreement between the immunoassay and the bioassay of insecticidal potency in terms of international units and there were two distinct immunoprecipitate peaks.
15 citations
TL;DR: Cell propagation of B. thuringiensis in distilled water containing 500 ppm of diazinon and malathion indicated metabolic breakdown of these compounds, and growth rates in broth cultures containing insecticides were measured.
Abstract: Growth rates of Bacillus thuringiensis var. thuringiensis Berliner in broth cultures containing insecticides were measured. Insecticides tested for compatibility included chlorinated hydrocarbons and their epoxdies, carbamates, and oreganophosphates. Of these insecticides, only aldrin, heptachlor, and DDT at the rates of 0.93, 2.25, and 4.5 ppm significantly reduced growth rates. The chlorinated hydrocarbon epoxides, organophosphates, and carbamates had no significant effects on growth rates at these levels. Cell propagation of B. thuringiensis in distilled water containing 500 ppm of diazinon and malathion indicated metabolic breakdown of these compounds.
TL;DR: The results showed that it was possible to use S. flava in a quantative assay of the β-exotoxin activity of B. thuringiensis, and the antibacterial effect on S.Flava was correlated with the amount of exotoxin as determined by absorption at 260 nm as well as to the toxic response in bioassays using the larvae of the housefly.
Abstract: Summary.
The β-exotoxin of Bacillus thuringiensis var. thuringiensis suppressed the growth of Sarcina flava and certain other bacteria. The antibacterial effect on S. flava was correlated with the amount of exotoxin as determined by absorption at 260 nm as well as to the toxic response in bioassays using the larvae of the housefly. Growth inhibition of S. flava could be shown in cup plate assay of the cellfree supernatant of B. thuringiensis var. thuringiensis cultures, prepurified and purified β-exotoxin. The results showed that it was possible to use S. flava in a quantative assay of the β-exotoxin activity of B. thuringiensis.
TL;DR: Bacillus thuringiensis Berliner grown at 14 C on a chemically defined liquid medium slowly produced spores and parasporal inclusions that attained 50 to 100% of that of cultures grown at 30 C.
Abstract: Bacillus thuringiensis var. thuringiensis Berliner grown at 14 C on a chemically defined liquid medium slowly produced spores and parasporal inclusions. Sporulation ultimately attained 50 to 100% of that of cultures grown at 30 C.
TL;DR: Commercial Bacillus thuringiensis Berliner preparations were effective for control of the California oakworm, Phryganidia californica Packard, in field trials conducted in 3 different climatic areas of northern California.
Abstract: Commercial Bacillus thuringiensis Berliner preparations were effective for control of the California oakworm, Phryganidia californica Packard, in field trials conducted in 3 different climatic areas of northern California. The preparations tested were Biotrol® Dustable BTB 183 2.5 D, Biotrol® Wettable BTB 183 25 w, and Thuricide® 90 TS 950-T. Application was timed to coincide with the 3rd larval instar, when a change in feeding behavior increased the exposure of the larvae to the B. thuringimsis deposits.
TL;DR: The major larvicidal activity against Haematobia irritans (L.) in a commercial product of Bacillus thuringiensis Berliner (Bakthane L-69®, Rohm & Haas Co.) was found in the water-insoluble fraction.
Abstract: The major larvicidal activity against Haematobia irritans (L.) in a commercial product of Bacillus thuringiensis Berliner (Bakthane L-69®, Rohm & Haas Co.) was found in the water-insoluble fraction. The toxins appeared to be calcium compounds which, when freed from calcium and solubilized at neutral pH, had the characteristics of B. t .-β-exotoxin (previously referred to as fly factor). When these toxins were administered to cattle in their insoluble state, they were excreted with the feces and were active against immature horn flies. The spores and crystals were ineffectual against immature horn flies, and the spores did not germinate and proliferate in bovine feces.
TL;DR: Subletale Konzentrationen von Terramycin hemmen in Drosophila teilweise die toxische Wirkung des hitzestabilen Exotoxins von Bacillus thuringiensis, wobei die Steilheit der Dosis-Mortalitätskurven nicht verändert wird.
Abstract: Subletale Konzentrationen von Terramycin hemmen inDrosophila teilweise die toxische Wirkung des hitzestabilen Exotoxins vonBacillus thuringiensis, wobei die Steilheit der Dosis-Mortalitatskurven nicht verandert wird. Es wird die Hypothese begrundet, dass es sich um eine kompetitive Hemmung des Exotoxins durch das Antibioticum handeln konnte.
TL;DR: Replicated field plot studies indicated that the δ-endotoxin produced by these biological agents can provide adequate control of the cabbage caterpillar complex when applied on a regular weekly basis throughout the growing season.
TL;DR: The HD-1 formulation of the δ-endotoxin of Bacillus thuringiensis Berliner was effective against the cabbage looper, Trichoplusia ni (Hubner), on cabbage in field tests when between 1.1 and 4.5×109 international units were applied once a week throughout the season.
Abstract: The HD-1 formulation of the δ-endotoxin of Bacillus thuringiensis Berliner was effective against the cabbage looper, Trichoplusia ni (Hubner), on cabbage in field tests when between 1.1 and 4.5×109 international units (IU) were applied once a week throughout the season. Applications of 2.2 and 4.5×109 IU/acre were equally effective whether they were applied once a week or every 10 days.
Journal Article•
TL;DR: The numbers of insect predators of oakmoth larvae were apparently unchanged by the Bacillus thuringiensis treatments and no phytotoxicity was noticed, and no handling or disposal difficulties were encountered.
Abstract: BACILLUS THURINGIENSIS preparations proved to be highly effective for oakmoth control during field trials conducted in three areas of differing climate in northern California. The Bacillus thuringiensis preparations tested were Biotrol Dustable BTB 183 2.5D, Biotrol Wettable BTB 183 25 W, and Thuricide 90 TS 950-T. They were found to be equally effective for oakmoth control, though they differed in persistence of viable spores. Three types of equipment were used to apply the sprayable preparations, and all produced effective coverage but showed marked differences in wastage of material. Only one type of equipment was available for applying the dustable preparation. Application was timed to coincide with the early third instar of the oakmoth larvae, when a change in feeding behavior increased their exposure to the Bacillus thuringiensis. All three preparations were apparently fully compatible with the equipment for application, and no handling or disposal difficulties were encountered. The numbers of insect predators of oakmoth larvae were apparently unchanged by the Bacillus thuringiensis treatments and no phytotoxicity was noticed.
Patent•
01 Jun 1971
TL;DR: In this article, the authors describe the production of the ExotoXin of Bacillus ThuringIensis in high yielding USING a high CARBOHYDRATE MEDIUM and an ACRYSTALLIFEROUS MUTANT OF BACILLUS THURINGIENSIS VAR.
Abstract: METHOD FOR THE PRODUCTION OF THE EXOTOXIN OF BACILLUS THURINGIENSIS IN HIGH YIELD USING A HIGH CARBOHYDRATE MEDIUM AND AN ACRYSTALLIFEROUS MUTANT OF BACILLUS THURINGIENSIS VAR. THURINGIENSIS.
TL;DR: A commercial formulation of Bacillus thuringiensis Berliner, Biotrol BTB 183-25 W, was fed to dairy cattle in an attempt to control house fly larvae in the feces, and in an in vitro experiment, complete control of home fly larvae was obtained.
Abstract: A commercial formulation of Bacillus thuringiensis Berliner, Biotrol BTB 183-25 W, was fed to dairy cattle in an attempt to control house fly, Musca domestica L., larvae in the feces. A maximum lanai mortality of 32% was obtained when cows were fed 3200 ppm of this formulation.
In an in vitro experiment, complete control of home fly larvae was obtained at a level of 12,800 ppm of feces.
Journal Article•
Patent•
20 Sep 1971
TL;DR: In this paper, the Bacillus thuringiensis is used to form spores and protein crystals, and the spores are rendered non-viable by treating them with 0.5-5% by weight, based on the weight of the culture suspension, of hydrogen peroxide, or at least 0.25% of #-propiolactone but insufficient to substantially affect the insecticidal activity of the protein crystals.
Abstract: 1323806 Microbial insecticides SUMITOMO CHEMICAL CO Ltd 20 Sept 1971 [21 Sept 1970] 43646/71 Heading A5E [Also in Division C6] In the preparation of insecticidal compositions based on Bacillus thuringiensis, the Bacillus is cultivated to form spores and protein crystals, and the spores are rendered non- viable by treating them with 0.5-5% by weight, based on the weight of the culture suspension, of hydrogen peroxide, or at least 0.25% by weight of #-propiolactone but insufficient to substantially affect the insecticidal activity of the protein crystals.
TL;DR: Two bioassay techniques for the standardization of commercially produced Bacillus thuringiensis var.
Abstract: Two bioassay techniques for the standardization of commercially produced Bacillus thuringiensis var. thuringiensis Berliner were simultaneously compared. A microbial insecticide preparation containing spores and toxic by products of this insect pathogen has been used as a standard for bioassays in the laboratory of Nutrilite Products, Inc., for over 10 years against saltmarsh caterpillar, Estigmene acrea (Drury), and for over 1 year on the cabbage looper, Trichoplusia ni (Hubner). While the median lethal dose (LD50) of the standard varied from day to day in both bioassays, the slope of the standard was constant. Similarly, the ratio of standard LD50 to unknown LD50 determined on different days was constant. There were no significant differences between the toxicity unit values as determined by the 2 bioassay techniques.
TL;DR: The ability of solubilized Bacillus thuringiensis Berliner δ-endotoxin to inhibit bovine pancreatic trypsin was used to determine the toxicity of preparations and a straight line was found that can be used to predict the LD50 for silkworm where the In50 of a preparation has been determined.
Abstract: The ability of solubilized Bacillus thuringiensis Berliner δ-endotoxin to inhibit bovine pancreatic trypsin was used to determine the toxicity of preparations. When the In50 causing enzymatic inhibition in larval silkworm, Bombyx mori (L.), was plotted on graph paper as the ordinate and the lethal dose (LD50) at 72 hours after oral injection of the δ-endotoxin was plotted as the abscissa, the relationship was found to produce a straight line that can be used to predict the LD50 for silkworm where the In50 of a preparation has been determined.