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Bacillus thuringiensis

Jenny M Greenwood, Barbara Milutinović, Robert Peuß, Sarah Behrens, Daniela Esser, Philip Rosenstiel, Hinrich Schulenburg, Joachim Kurtz
BACKGROUND: The phenomenon of immune priming, i.e. enhanced protection following a secondary exposure to a pathogen, has now been demonstrated in a wide range of invertebrate species. Despite accumulating phenotypic evidence, knowledge of its mechanistic underpinnings is currently very limited. Here we used the system of the red flour beetle, Tribolium castaneum and the insect pathogen Bacillus thuringiensis (Bt) to further our molecular understanding of the oral immune priming phenomenon...
April 26, 2017: BMC Genomics
Nan Jia, Ming-Zhu Ding, Yang Zou, Feng Gao, Ying-Jin Yuan
Adaptive evolution by serial subcultivation of co-cultured Bacillus thuringiensis and Ketogulonicigenium vulgare significantly enhanced the productivity of 2-keto-L-gulonic acid in two-step vitamin C production. The adaptation mechanism in K. vulgare-B. thuringiensis consortium was investigated in this study based on comparative genomics and metabolomics studies. It was found that the growth, anti-oxidation, transcription and regulation were significantly enhanced in the adapted consortium. The mutation of the genes, which encode amidohydrolase in adapted K...
April 25, 2017: Scientific Reports
Lionel Makart, Florian Commans, Annika Gillis, Jacques Mahillon
pXO16, a large plasmid originating from Bacillus thuringiensis serovar israelensis, displays unique conjugation capacities: besides efficient self-transfer, it is able to mobilize and retro-mobilize non-conjugative plasmids, including those missing an oriT and/or a mob gene, also known as "non-mobilizable" plasmids. In this paper, another peculiar transfer property of pXO16 is described. This element is indeed able to transfer chromosomal loci at frequencies of ca. 10(-5)-10(-6) transconjugants/donor cell. Whereas most other chromosomal transfer systems occur via the integration of the conjugative elements into the chromosome prior to its transfer, pXO16 appears to transfer the chromosomal markers in the absence of physical integration, but rather through a "donation-type" mobilization...
April 20, 2017: Plasmid
K D Johnson, L A Campbell, M D Lepping, D M Rule
Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), and northern corn rootworm, Diabrotica barberi Smith and Lawrence (Coleoptera: Chrysomelidae), are important insect pests in corn, Zea mays L. For more than a decade, growers have been using transgenic plants expressing proteins from the bacterium Bacillus thuringiensis (Bt) to protect corn roots from feeding. In 2011, western corn rootworm populations were reported to have developed resistance to Bt hybrids expressing Cry3Bb1 and later found to be cross-resistant to hybrids expressing mCry3A and eCry3...
April 18, 2017: Journal of Economic Entomology
Guiwen Wang, Huanjun Chen, Xiaochun Wang, Lixin Peng, Yuan Peng, Yong-Qing Li
Bacillus thuringiensis (Bt) is the most widely used microbial insecticide. To clarify the mechanism of bacterial resistance to ethanol toxicity, the present study investigated the effects of 70% (v/v) ethanol at a moderate temperature (65°C) on Bt spore germination by single-cell Raman spectroscopy and differential interference contrast microscopy. We found that over 80% of Bt spores were inviable after 30 min of treatment. Moreover, ethanol treatment affected spore germination; the time for initiation of rapid calcium dipicolinate (CaDPA) release (i...
April 20, 2017: Applied Optics
Karine Monceau, François-Xavier Dechaume-Moncharmont, Jérôme Moreau, Camille Lucas, Rémi Capoduro, Sébastien Motreuil, Yannick Moret
The pace-of-life syndrome (POLS) hypothesis is an extended concept of the life history theory that includes behavioural traits. The studies challenging the POLS hypothesis often focus on the relationships between a single personality trait and a physiological and/or life history traits. While pathogens represent a major selective pressure, few studies have been interested in testing relationships between behavioural syndrome, and several fitness components including immunity. The aim of this study is to address this question in the mealworm beetle, Tenebrio molitor, a model species in immunity studies...
April 20, 2017: Journal of Animal Ecology
Haruka Endo, Shiho Tanaka, Kazuhiro Imamura, Satomi Adegawa, Shingo Kikuta, Ryoichi Sato
In this study, we examined insect and human ABCC transporters closely related to the lepidopteran ABC transporter C2 (ABCC2), a powerful receptor for the Bacillus thuringiensis Cry toxin, for their responses to various Cry toxins. ABCC2 and the lepidopteran ABC transporter C3 (ABCC3) conferred cultured cells with susceptibility to a lepidopteran-specific Cry1Aa toxin but not to lepidopteran-specific Cry1Ca and Cry1Da. One coleopteran ABCC transporter specifically responded to a coleopteran-specific Cry8Ca toxin...
April 14, 2017: Peptides
Alexandra Plácido, Idalina Bragança, Mariela Marani, Alyne Rodrigues de Araujo, Andreanne Gomes Vasconcelos, Krystallenia Batziou, Valentina F Domingues, Peter Eaton, José Roberto S A Almeida Leite, Cristina Delerue-Matos
Escherichia coli is one of the most common etiological agents of diarrhea in developing countries. The appearance of resistant E. coli prevents treatment of these infections. Biotechnological products incorporating antimicrobial peptides are currently being considered in applications to prevent intestinal infections by these bacteria. The aim of this study was to evaluate the antibacterial activity of the peptide PcL342-354C, which is derived from the toxin Cry1Ab16 from Bacillus thuringiensis, against E. coli strains...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Zahia Djenane, Farida Nateche, Meriam Amziane, Joaquín Gomis-Cebolla, Fairouz El-Aichar, Hassiba Khorf, Juan Ferré
This work represents the first initiative to analyze the distribution of B. thuringiensis in Algeria and to evaluate the biological potential of the isolates. A total of 157 isolates were recovered, with at least one isolate in 94.4% of the samples. The highest Bt index was found in samples from rhizospheric soil (0.48) and from the Mediterranean area (0.44). Most isolates showed antifungal activity (98.5%), in contrast to the few that had antibacterial activity (29.9%). A high genetic diversity was made evident by the finding of many different crystal shapes and various combinations of shapes within a single isolate (in 58...
April 13, 2017: Toxins
Ardahan Eski, İsmail Demir, Kazım Sezen, Zihni Demirbağ
Use of chemical pesticides in agriculture harms humans, non-target organisms and environments, and causes increase resistance against chemicals. In order to develop an effective bio-pesticide against coleopterans, particularly against Agelastica alni (Coleoptera: Chrysomelidae) which is one of the serious pests of alder leaf and hazelnut, we tested the insecticidal effect of 21 Bacillus isolates against the larvae and adults of the pest. Bacillus thuringiensis var. tenebrionis-Xd3 (Btt-Xd3) showed the highest insecticidal effect based on screening tests...
May 2017: World Journal of Microbiology & Biotechnology
Liming Zhao, Barry W Alto, Dagne Duguma
Aedes aegypti (L.) is the vector responsible for transmitting dengue, chikungunya, yellow fever, and Zika viruses, as well as other pathogens. Microbial larvicides based on Bacillus thuringiensis Berliner israelensis (Bti) and Saccharopolyspora spinosa Mertz and Yao, such as VectoBac 12AS and Natular 2EC, have been shown to be effective in reducing larval populations of Ae. aegypti. We examined the gene expression of two detoxification enzymes, glucosyl and glucuronosyl transferases (AaeGGT1 and AaeGGT2), through developmental stages and a time course study in response to larvicide exposure using qualitative real-time polymerase chain reaction (qPCR)...
February 25, 2017: Journal of Medical Entomology
Ana M Camargo, Pedro Castañera, Gema P Farinós, Fangneng Huang
The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a major target pest of Bacillus thuringiensis (Bt) maize and cotton in America. Since the commercialization of Cry1F maize (event TC1507) in 2003, resistance to Cry1F maize in field populations of S. frugiperda has occurred in Puerto Rico, Brazil and the southeast region of the United States. In this paper, we conducted a comparative analysis of the inheritance of two Cry1F-resistant colonies of S. frugiperda originated from Puerto Rico (PR) and Florida (FL), respectively...
April 6, 2017: Journal of Invertebrate Pathology
Devendra Jain, Sita D Sunda, Suman Sanadhya, Dhruba Jyoti Nath, Sunil K Khandelwal
Novel cry genes are potential candidates for resistance management strategies, due to their different structures and modes of action. Therefore, it is desirable to clone and express novel cry genes from several new isolates of Bacillus thuringiensis (Bt). In the present study, 28 Bt strains were characterized at morphological and molecular level. All these strains are Gram positive, endospore forming and had shown different crystal morphologies when viewed under the microscope. The ARDRA (16S rDNA PCR-RFLP technique) with AluI, HaeIII, HinfI and TaqI produced unique and distinguishable restriction patterns used for the molecular characterization of these isolates...
May 2017: 3 Biotech
Smita Agarwal
Size-segregated aerosol samplings were carried out near the potential sources of airborne biological particles i.e. at a landfill site, an agricultural field and a road side restaurant-cluster site in winter, spring and summer seasons during 2013-2015 in New Delhi. The culturable airborne bacterial (CAB) concentrations showed significant seasonal variation from higher to moderate in spring and winter seasons and lowest during summer. Highest CAB concentrations were observed at the Okhla landfill site followed by restaurant-cluster area and agriculture site...
April 7, 2017: Environmental Science and Pollution Research International
Jian Jiang, Ying Huang, Changlong Shu, Mario Soberón, Alejandra Bravo, Chunqing Liu, Fuping Song, Jinsheng Lai, Jie Zhang
The Bacillus thuringiensis strain HBF-18 (CGMCC2070), containing two cry genes (cry8-like and cry8Ga), is toxic to Holotrichia oblita larvae. Both Cry8-like and Cry8Ga proteins are active against this insect pest, while Cry8-like is the more toxic protein. To analyze the binding characteristics of Cry8-like and Cry8Ga proteins to brush border membrane vesicles (BBMV) in H. oblita larvae, binding assays were conducted with a fluorescent DyLight488-labeled Cry8-like toxin. Results of binding saturation assays demonstrated that Cry8-like binds specifically to binding sites on BBMV from H...
April 7, 2017: Applied and Environmental Microbiology
Eva Vianey Alquisira-Ramírez, Guadalupe Peña-Chora, Víctor Manuel Hernández-Velázquez, Andrés Alvear-García, Iván Arenas-Sosa, Ramón Suarez-Rodríguez
The sublethal effects of two strains of Bacillus thuringiensis, which were virulent in vitro to Varroa destructor, were measured on Apis mellifera. The effects of five concentrations of total protein (1, 5, 25, 50 and 100μg/mL) from the EA3 and EA26.1 strains on larval and adult honey bees were evaluated for two and seven days under laboratory conditions. Based on the concentrations evaluated, total protein from the two strains did not affect the development of larvae, the syrup consumption, locomotor activity or proboscis extension response of adults...
April 4, 2017: Ecotoxicology and Environmental Safety
Yolanda Bel, Núria Banyuls, Maissa Chakroun, Baltasar Escriche, Juan Ferré
Vip3 proteins are secretable proteins from Bacillus thuringiensis whose mode of action is still poorly understood. In this study, the activation process for Vip3 proteins was closely examined in order to better understand the Vip3Aa protein stability and to shed light on its structure. The Vip3Aa protoxin (of 89 kDa) was treated with trypsin at concentrations from 1:100 to 120:100 (trypsin:Vip3A, w:w). If the action of trypsin was not properly neutralized, the results of SDS-PAGE analysis (as well as those with Agrotis ipsilon midgut juice) equivocally indicated that the protoxin could be completely processed...
April 7, 2017: Toxins
Yiyun Wei, Shuwen Wu, Yihua Yang, Yidong Wu
The cotton bollworm Helicoverpa armigera (Hübner) is one of the most damaging cotton pests worldwide. In China, control of this pest has been dependent on transgenic cotton producing a single Bacillus thuringiensis (Bt) protein Cry1Ac since 1997. A small, but significant, increase in H. armigera resistance to Cry1Ac was detected in field populations from Northern China. Since Vip3Aa has a different structure and mode of action than Cry proteins, Bt cotton pyramids containing Vip3Aa are considered as ideal successors of Cry1Ac cotton in China...
April 5, 2017: Toxins
Estefania O Juárez-Hernández, Luz E Casados-Vázquez, Dennis K Bideshi, R Salcedo-Hernández, José E Barboza-Corona
ChiA74 has modular structure that includes a secretion signal peptide (sp) sequence, and catalytic (CD), chitin insertion (CID), fibronectin type-III (FnIII) and chitin binding (CBD) domains. We described for the first time the existence of a putative CID in ChiA74. Mature ChiA74 lacking its sp sequence (rChiA74Δsp, ∼70kDa) and two truncated versions, rChiA74Δsp-60, rChiA74Δsp-50 lacking, respectively, CBD and CDB-FnIII were produced. rChiA74Δsp and rChiA74Δsp-60 are unstable and were processed to generate stable proteins of ∼50kDa...
April 2, 2017: International Journal of Biological Macromolecules
Z Svobodová, E C Burkness, O Skoková Habuštová, W D Hutchison
Understanding indirect, trophic-level effects of genetically engineered plants, expressing insecticidal proteins derived from the bacterium, Bacillus thuringiensis (Bt), is essential to the ecological risk assessment process. In this study, we examine potential indirect, trophic-level effects of Bt-sensitive prey using the predator, Harmonia axyridis (Pallas), feeding upon Spodoptera frugiperda (J.E. Smith) larvae, which had delayed development (lower body mass) following ingestion of Cry1Ab maize leaves. We found no adverse effects on development and survival when H...
March 28, 2017: Journal of Economic Entomology
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