Action of natural phytosanitary products onBacillus thuringiensissubsp.kurstakiS-1905

AbstractThe objective of this study was to evaluate the effects of natural phytosanitary products (NPs) on spores and crystals ofBacillus thuringiensissubsp.kurstakiS-1905 (Btk S-1905). For the spore assay, NPs and bacteria were applied in combination and individually. For the combined application, Btk S-1905 + NP mixtures were inoculated on nutrient agar (NA), and for the separate applications, the NPs were spread on NA plates, which were later inoculated with the pathogen. The number of colony-forming units (CFU) per milliliter was quantified after 18 h of incubation. For the crystal protein degradation assay, the Btk S-1905 + NP mixtures were added to the diet ofAnticarsia gemmatalis(Lepidoptera: Erebidae), and mortality was evaluated at the following time points: 12, 24, 48, and 72 h. Scanning electron microscopy and agarose gel electrophoresis were carried out. Biogermex and Ecolife®reduced the CFU ml−1in both combined and separate applications. Biogermex, Ecolife®, and Planta Clean were antagonistic to the action of bacterial toxins, and no product affected the morphology or resulted in the degradation of the crystal proteins. The remaining products evaluated did not reduce the CFU ml−1and had additive effect when combined with the crystal toxin.

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Transformation of Pseudomonas syringae with nonconjugative R plasmids

Canadian Journal of Microbiology ◽

10.1139/m81-118 ◽

1981 ◽

Vol 27 (8) ◽

pp. 759-765 ◽

Cited By ~ 3

Author(s):

Dennis C. Gross ◽

Anne K. Vidaver

Keyword(s):

Molecular Weight ◽

Pseudomonas Syringae ◽

Plasmid Dna ◽

Gel Electrophoresis ◽

Recipient Cell ◽

Heat Pulse ◽

Agarose Gel ◽

Agarose Gel Electrophoresis ◽

Colony Forming Units ◽

R Plasmids

Transformation of Pseudomonas syringae strains with plasmid DNA occurs at a frequency of 1 × 10−3 to 4 × 10−9 per recipient cell, depending on the strain, plasmid, and conditions for transformation. R plasmids used successfully in transformation were pR0161 (26 × 106 molecular weight) and RSF1010 (5.5 × 106 molecular weight). Transformation involved growing the recipient cells to approximately 8 × 108 colony-forming units per millilitre in 50 mL of a nutrient broth. After washes with a 150 mM CaCl2 – 10% (v/v) glycerol mixture, cells were concentrated 20-fold and resuspended in this solution. The cells then were incubated with purified plasmid DNA for 1 h prior to a heat pulse at 45 °C for 2 min. Transformants were selected by antibiotic resistance and plasmid presence was verified by agarose gel electrophoresis. With plasmid pCG131 (34 × 106 molecular weight; putatively associated with syringomycin production), transformation of syringomycin-negative P. syringae strains that contained no detectable plasmid or were cured of pCG131 was unsuccessful, whether the plasmid was used alone or in combination with either pR0161 or RSF1010.

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Luminography – an Alternative Assay for Detection of von Willebrand Factor Multimers

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647016 ◽

1988 ◽

Vol 60 (02) ◽

pp. 133-136 ◽

Cited By ~ 50

Author(s):

R Schneppenheim ◽

H Plendl ◽

U Budde

Keyword(s):

Von Willebrand Factor ◽

Gel Electrophoresis ◽

Detection Methods ◽

Agarose Gel ◽

Agarose Gel Electrophoresis ◽

Luminescence Assay ◽

Von Willebrand ◽

Willebrand Factor

SummaryA luminescence assay was adapted for detection of von Willebrand factor multimers subsequent to SDS-agarose gel electrophoresis and electroblotting onto nitrocellulose. The method is as fast as chromogenic detection methods and appears to be as sensitive as autoradiography without the disadvantages of the latter.

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