Loss of Bacillus thuringiensis var. israelensis Larvicidal Activity and Its Distribution in Benthic Substrates and Hyporheic Zone of Streams

1993 ◽  
Vol 50 (2) ◽  
pp. 443-451 ◽  
Author(s):  
M. E. Tousignant ◽  
J. L. Boisvert ◽  
A. Chalifour
Keyword(s):  
Bacillus Thuringiensis ◽  
Water Samples ◽  
Short Distance ◽  
Hyporheic Zone ◽  
Open Channel ◽  
Field Trials ◽  
Toxic Activity ◽  
Channel Water ◽  
Neonate Larvae ◽  
Additional Losses

Numerous field trials have indicated that the effectiveness of Bacillus thuringiensis var. israelensis (B.t.i.) is limited to a short distance in streams, but the reasons for loss of toxicity have not been identified. Two streams were treated with B.t.i. and experiments were conducted to monitor the transfer of B.t.i. toxicity from the channel water to different compartments within the stream. These compartments included benthic substrates such as sediments, periphyton covering bedrocks, vegetation (moss and grass), and water samples taken from hyporheic probes (15, 35, and 65 cm depth). B.t.i. toxic activity was measured using bioassays with mosquito neonate larvae. Results indicated that loss to the hyporheic zone accounted for a significant fraction of B.t.i. removal from the open-channel water. Additional losses were attributable chiefly to moss, but sediments may play an important role in filtering or retaining B.t.i. toxic particles.

Design and optimization of open-channel water ultraviolet disinfection reactor

2019 ◽  
Vol 73 (6) ◽  
pp. 1423-1436
Author(s):  
Tipu Sultan ◽  
Zeshan Ahmad ◽  
Khazar Hayat
Keyword(s):  
Open Channel ◽  
Ultraviolet Disinfection ◽  
Design And Optimization ◽  
Channel Water

Optimized Scheduling of Cascade Pumping Stations in Open-Channel Water Transfer Systems Based on Station Skipping

2019 ◽  
Vol 145 (7) ◽  
pp. 05019011 ◽  
Author(s):  
Zhao Zhang ◽  
Xiaohui Lei ◽  
Yu Tian ◽  
Lingling Wang ◽  
Hao Wang ◽  
...  
Keyword(s):  
Open Channel ◽  
Water Transfer ◽  
Channel Water ◽  
Pumping Stations

Insecticidal Activity of a Cry1Ca toxin of Bacillus thuringiensis Berliner (Firmicutes: Bacillaceae) and Its Synergism with the Cyt1Aa Toxin Against Aedes aegypti (Diptera: Culicidae)

2020 ◽  
Vol 57 (6) ◽  
pp. 1852-1856
Author(s):  
Sebastian E González-Villarreal ◽  
Mónica García-Montelongo ◽  
Jorge E Ibarra
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Synergistic Effect ◽  
Joint Action ◽  
Recombinant Strain ◽  
Crystal Morphology ◽  
Graphical Method ◽  
Toxic Activity ◽  
Lepidopteran Species ◽  
Gene Coding

Abstract The Cry1C protein family of Bacillus thuringiensis form bipyramidal crystals, which are commonly associated with toxic activity against lepidopteran species; however, some members of this family may also be toxic to dipterans. In the present work, the Cry1Ca16 protein, synthesized by the B. thuringiensis LBIT-1217 strain, was analyzed. The gene coding for this protein was amplified, sequenced, and cloned into the pSTAB vector, which was electro-transferred into the acrystalliferous B. thuringiensis 4Q7 strain. The recombinant strain showed the expected bipyramidal crystal morphology, identical to the original LBIT-1217 strain and exhibited toxicity against larvae of Aedes aegypti (Diptera). Pure crystals from the recombinant strain were used in bioassays against Ae. aegypti larvae, estimating an LC50 of 4.61 μg/ml. Further studies on Cry1Ca16 mosquitocidal potential included joint-action tests with the Cyt1Aa protein crystals from B. thuringiensis israelensis. An LC50 using pure Cyt1Aa crystals was estimated at 0.73 μg/ml, whereas an LC50 of 0.61 μg/ml was estimated when both toxins were tested together. Data from these bioassays was analyzed using joint-action tests such as the Tammes-Bakuniak graphical method and the formula proposed by Tabashnik (1992). Both tests clearly showed a synergistic effect between these two toxins.

Alkaline extraction of toxin from spores of the mosquito pathogen, Bacillus sphaericus strain 1593

1983 ◽  
Vol 29 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Elizabeth West Davidson
Keyword(s):  
Molecular Weight ◽  
Bacillus Thuringiensis ◽  
Bacillus Sphaericus ◽  
Alkaline Extraction ◽  
Toxic Activity ◽  
Crystal Toxin ◽  
Mosquito Pathogen

Toxin was extracted from spores of the mosquito pathogen Bacillus sphaericus strain 1593 using 0.05 M NaOH. The molecular weight of this toxin was 35 000–54 000. Toxic activity of this extract was resistant to a variety of enzymes including subtilisin, but was degraded by pronase. Antiserum produced to 1593 spore toxin neutralized spore toxin and cytoplasmic toxin activity, but did not react with Bacillus thuringiensis var. israelensis crystal toxin, nor did var. israelensis toxin antiserum react with B. sphaericus toxin. Crystallike parasporal inclusions accompanying the B. sphaericus 1593 spores were removed by NaOH extraction.

scholarly journals Field trials of Bacillus thuringiensis var. israelensis against blackfly larvae in Japan

1985 ◽  
Vol 36 (4) ◽  
pp. 371-373 ◽  
Author(s):  
Yuzuru NAKAMURA ◽  
Akihiro KANAYAMA ◽  
Hideki SATO ◽  
Kazuyo FUJITA ◽  
Yuichiro TABARU ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Trials ◽  
Blackfly Larvae

scholarly journals Expression of the p20 Gene from Bacillus thuringiensis H-14 Increases Cry11A Toxin Production and Enhances Mosquito-Larvicidal Activity in Recombinant Gram-Negative Bacteria

2001 ◽  
Vol 67 (7) ◽  
pp. 3010-3015 ◽  
Author(s):  
Y. Xu ◽  
M. Nagai ◽  
M. Bagdasarian ◽  
T. W. Smith ◽  
E. D. Walker
Keyword(s):  
Bacillus Thuringiensis ◽  
Toxin Production ◽  
Gram Negative Bacteria ◽  
Western Blots ◽  
Toxic Activity ◽  
Gram Negative ◽  
E Coli ◽  
Recombinant Cells ◽  
C Terminus ◽  
Insoluble Form

ABSTRACT Experimental analyses with recombinant Escherichia coliand Pseudomonas putida transformed with plasmids bearing genes coding for the Cry11A toxin and P20 protein from Bacillus thuringiensis H-14 showed that cells producing both proteins were more toxic when fed to third-instar Aedes aegypti larvae than were cells expressing cry11A alone; the 50% lethal concentrations were in the range of 104 to 105cells/ml. Western blots revealed a higher production of Cry11A when thep20 gene was coexpressed. Cry11A was detected primarily in insoluble form in recombinant cells. Cry11A was not detected inP. putida when P20 was not coproduced, and these recombinants were not toxic to larvae, whereas P. putidarecombinants producing both proteins were toxic at concentrations similar to those for E. coli. A coelution experiment was conducted, in which a p20 gene construct producing the P20 protein with an extension of six histidines on the C terminus was mixed with the Cry11A protein. The results showed that Cry11A bound to the P20(His6) on a nickel chelating column, whereas Cry11A produced without the P20(His6) protein was washed through the column, thus indicating that Cry11A and P20 physically interact. Thus, P20 protein either stabilizes Cry11A or helps it attain the folding important for its toxic activity.

Open-channel, water-in-oil emulsification in paper-based microfluidic devices

Lab on a Chip ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1436-1441 ◽  
Author(s):  
C. Li ◽  
M. Boban ◽  
A. Tuteja
Keyword(s):  
Microfluidic Device ◽  
Open Channel ◽  
Microfluidic Devices ◽  
Hydrogel Particles ◽  
Channel Water ◽  
Oil Emulsions

Fabrication of an open-channel, paper-based microfluidic device, utilizing selective wettability, capable of generating water-in-oil emulsions and fabricating hydrogel particles.

S1150403 Experimental Study of Open-Channel Water Brake as a Deceleration System for Rocket Sleds

2015 ◽  
Vol 2015 (0) ◽  
pp. _S1150403--_S1150403-
Author(s):  
Shinya SASAO ◽  
Daisuke NAKATA ◽  
Kazuyuki HIGASHINO
Keyword(s):  
Experimental Study ◽  
Open Channel ◽  
Channel Water
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