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Bacillus thuringiensis

Subhasree Ray, Vipin Chandra Kalia
Bacteria under stress conditions of excess of carbon (C) and limitations of nutrients divert its metabolism towards C storage as energy reservoir-polyhydroxyalkanoate (PHA). Different Bacillus species-B. cereus and B. thuringiensis, were monitored to produce PHA from different C sources-glucose, crude glycerol and their combination at 37 °C for period up to 192 h. PHA production and its composition was found to vary with feed and bacterial strains. PHA production on crude glycerol continued to increase up to 120 h, reaching a maximum of 2725 mg/L with an effective yield of 71% of the dry cell mass...
December 2017: Indian Journal of Microbiology
Yonglei Liu, Yinglong Wang, Changlong Shu, Kejian Lin, Fuping Song, Alejandra Bravo, Mario Soberón, Jie Zhang
Genetically modified crops that express insecticidal Bacillus thuringiensis (Bt) proteins have become a primary approach for control of lepidopteran (moth) and coleopteran (beetle) pests that feed by chewing the plants. However, the sap-sucking insects (Hemiptera) are not particularly susceptible to Bt toxins. In this study, we describe two Cry toxins (Cry64Ba and Cry64Ca) from a Bt 1012 strain showed toxicity against two important rice hemipteran pests, Laodelphax striatellus and Sogatella furcifera Both of these two proteins contain an ETX/MTX2 domain, and share common sequence features with the β-pore forming toxins...
November 17, 2017: Applied and Environmental Microbiology
Megan L Fritz, Alexandra M DeYonke, Alexie Papanicolaou, Stephen Micinski, John Westbrook, Fred Gould
Adaptation to human-induced environmental change has the potential to profoundly influence the genomic architecture of affected species. This is particularly true in agricultural ecosystems, where anthropogenic selection pressure is strong. Heliothis virescens primarily feeds on cotton in its larval stages and US populations have been declining since the widespread planting of transgenic cotton, which endogenously expresses proteins derived from Bacillus thuringiensis (Bt). No physiological adaptation to Bt toxin has been found in the field, so adaptation in this altered environment could involve: 1) shifts in host plant selection mechanisms to avoid cotton, 2) changes in detoxification mechanisms required for cotton-feeding versus feeding on other hosts, or 3) loss of resistance to previously used management practices including insecticides...
November 13, 2017: Molecular Ecology
Shiho Tanaka, Haruka Endo, Satomi Adegawa, Ami Iizuka, Kazuhiro Imamura, Shingo Kikuta, Ryoichi Sato
Because Bombyx mori ABC transporter C2 (BmABCC2) has 1000-fold higher potential than B. mori cadherin-like protein as a receptor for Bacillus thuringiensis Cry1Aa toxin (Tanaka et al., 2013), the gate-opening ability of the latent pore under six extracellular loops (ECLs) of BmABCC2 was expected to be the reason for its higher potential (Heckel, 2012). In this study, cell swelling assays in Sf9 cells showed that BmABCC2 mutants lacking substrate-excreting activity retained receptor activity, indicating that the gate-opening activity of BmABCC2 is not responsible for Cry1Aa toxicity...
November 8, 2017: Insect Biochemistry and Molecular Biology
Rodney N Nagoshi, Shelby Fleischer, Robert L Meagher
Gene introgression between related pest populations is an important component in the assessment of how rapidly economically important traits, such as pesticide resistance, can spread within a region. An example of this is provided by the noctuid moth Spodoptera frugiperda (J.E. Smith), or fall armyworm, which is composed of two 'host strains' that differ in their host plant preferences. Resistance to a Bacillus thuringiensis toxin has been observed in some populations and there is concern about its spread throughout the Western Hemisphere...
November 8, 2017: Journal of Economic Entomology
Shoulin Jiang, Yongqing Lu, Yang Dai, Lei Qian, Adnan Bodlah Muhammad, Teng Li, Guijun Wan, Megha N Parajulee, Fajun Chen
Recent studies have highlighted great challenges of transgene silencing for transgenic plants facing climate change. In order to understand the impacts of elevated CO2 on exogenous Bacillus thuringiensis (Bt) toxins and transgene expression in transgenic rice under different levels of N-fertilizer supply, we investigated the biomass, exogenous Bt toxins, Bt-transgene expression and methylation status in Bt rice exposed to two levels of CO2 concentrations and nitrogen (N) supply (1/8, 1/4, 1/2, 1 and 2 N)...
November 7, 2017: Scientific Reports
Rong Li, Zhenzhen Yan, Juan Wang, Qisheng Song, Zhi Wang
BACKGROUND: Pardosa pseudoannulata is a prevailing spider species, and has been regarded as an important bio-control agent of insect pests in farmland of China. However, the available genomic and transcriptomic databases of P. pseudoannulata and their venom are limited, which severely hampers functional genomic analysis of P. pseudoannulata. Recently high-throughput sequencing technology has been proved to be an efficient tool for profiling the transcriptome of relevant non-target organisms exposed to Bacillus thuringiensis (Bt) protein through food webs...
November 7, 2017: BMC Biotechnology
Olga Bassy, Óscar Jiménez-Mateo, M Victoria Ortega, Carmen Granja, Juan Carlos Cabria
In the present study, we report the development of a real-time PCR assay for the identification of Bacillus anthracis, based on the amplification of a unique chromosomal marker, the E4 sequence, with dual hybridization probes. The assay was evaluated using a panel of ten B. anthracis strains, two B. anthracis isolates from human clinical samples, 12 B. anthracis environmental swabs and 40 non- B. anthracis strains. All 12 B. anthracis strains and clinical isolates were correctly detected, and the method did not show cross-reactions with other micro-organisms...
November 4, 2017: Molecular and Cellular Probes
Jyotsana Prakash, Rahul Kumar Gupta, Priyanka Xx, Vipin Chandra Kalia
Biodiesel industrial effluent rich in crude glycerol (CG) was processed to produce value-added product. Under continuous culture system, Bacillus amyloliquefaciens strain CD16 immobilized within its biofilm, produced 3.2 L H2/day/L feed, over a period of 60 days at a hydraulic retention time of 2 days. The effective H2 yield by B. amyloliquefaciens strain CD16 was 165 L/L CG. This H2 yield was 1.18-fold higher than that observed with non-biofilm forming Bacillus thuringiensis strain EGU45. Bioprocessing of the effluent released after this stage, by recycling it up to 25% did not have any adverse effect on H2 production by strain EGU45; however, a 25% reduction in yield was recorded with strain CD16...
November 4, 2017: Applied Biochemistry and Biotechnology
Yi-Huang Hsueh, Ping-Han Tsai, Kuen-Song Lin, Wan-Ju Ke, Chao-Lung Chiang
BACKGROUND: Zero-valent iron nanoparticles (ZVI NPs) have been used extensively for the remediation of contaminated soil and groundwater. Owing to their large active surface area, they serve as strong and effective reductants. However, the ecotoxicity and bioavailability of ZVI NPs in diverse ecological media have not been evaluated in detail and most studies have focused on non-nano ZVI or Fe(0). In addition, the antimicrobial properties of ZVI NPs have rarely been investigated, and the underlying mechanism of their toxicity remains unknown...
November 3, 2017: Journal of Nanobiotechnology
Faiza Saleem, Abdul Rauf Shakoori
The Cry (crystal) proteins from Bacillus thuringiensis are known to have toxicity against a variety of insects and have been exploited to control insect pests through transgenic plants and biopesticides. B. thuringiensis SBS BT-1 carrying the cry2 genes was isolated from soil samples in Pakistan. The 2-kb full length cry2Ac gene was cloned, sequenced, and submitted to the EMBL DNA database (Accession No. AM292031). For expression analysis, Escherichia coli DH5α was transformed with the fragment sub-cloned in pET22b expression vector using NdeI and HindIII restriction sites, and later confirmed by restriction endonuclease analysis...
November 3, 2017: Toxins
Xuesong Jiang, Kyle R Overdeep, Elliot R Wainwright, Timothy P Weihs, Hai-Quan Mao
The emergence of Bacillus anthracis as a potential bioterrorism and biological warfare agent points to the need for safe, effective, and economical sporicides for infection prevention and control. This work examined the efficacy of iodine vapor decontamination technologies to inactivate a surrogate for B. anthracis, Bacillus thuringiensis spores on glass materials. 10(6)-10(7) colony-forming units of spores inoculated onto circular glass cover slips were treated with different concentrations of iodine vapor under various temperature and relative humidity...
November 2, 2017: Current Microbiology
Tania Domínguez-Flores, María Dolores Romero-Bosquet, Diana Marcela Gantiva-Díaz, María José Luque-Navas, Colin Berry, Antonio Osuna, Susana Vílchez
The insecticidal Cry toxins produced by Bacillus thuringiensis (Bt) are increasingly important in the biological control of insect pests and vectors of human disease. Markets for Bt products and transgenic plants expressing their toxins are driven by their specificity, safety and the move away from chemical control agents. However, the high specificity of Cry toxins can also prove to be a limitation when there is no known Cry toxin active against a particular target. Novel activities can be discovered by screening natural Bt isolates or through modifications of the Cry proteins...
November 2, 2017: Scientific Reports
Damián A Grimi, Betiana Parody, María Laura Ramos, Marcos Machado, Federico Ocampo, Alan Willse, Samuel Martinelli, Graham Head
BACKGROUND: Maize technologies expressing Bacillus thuringiensis (Bt) insecticidal proteins are widely used in Argentina to control sugarcane borer (Diatraea saccharalis Fabricius). Unexpected D. saccharalis damage was observed to Bt maize events TC1507 (expressing Cry1F) and MON 89034 × MON 88017 (expressing Cry1A.105 and Cry2Ab2) in an isolated area of San Luis Province. D. saccharalis larvae were sampled from MON 89034 × MON 88017 fields in the area to generate a resistant strain (RR), which was subsequently characterized in plant and diet bioassays...
November 2, 2017: Pest Management Science
Jose E Pietri, Dangsheng Liang
Due in part to the development of insecticide resistance, the common bed bug, Cimex lectularius, has overcome human intervention efforts to make a global resurgence. The failure of chemical pesticides has created a need for novel strategies to combat bed bugs. While a number of insect pests are susceptible to the use of entomopathogenic microbes or microbial-derived toxins, biological control methods have not been thoroughly explored in bed bugs. Here, we tested the virulence of three entomopathogenic bacterial species in C...
October 24, 2017: Journal of Invertebrate Pathology
Bing Wang, Haiwen Wang, Jing Xiong, Qiaoni Zhou, Huan Wu, Liqiu Xia, Lin Li, Ziquan Yu
Cry6A represents a novel family of nematicidal crystal proteins from Bacillus thuringiensis. It has distinctive architecture as well as mechanism of action from Cry5B, a highly focused family of nematicidal crystal proteins, and even from other insecticidal crystal proteins containing the conserved three-domain. However, how nematode defends against Cry6A toxin remains obscure. In this study, the global defense pattern of Caenorhabditis elegans against Cry6Aa2 toxin was investigated by proteomic analysis. In response to Cry6Aa2, 12 proteins with significantly altered abundances were observed from worms, participating in innate immune defense, insulin-like receptor (ILR) signaling pathway, energy metabolism, and muscle assembly...
October 26, 2017: Scientific Reports
Desmi I Chandrasena, Ana M Signorini, Gustavo Abratti, Nicholas P Storer, Magdalena L Olaciregui, Analiza P Alves, Clinton D Pilcher
BACKGROUND: Transgenic maize (Zea mays L.) event TC1507 (Herculex® I insect protection), expressing Cry1F δ-endotoxin derived from Bacillus thuringiensis var. aizawai, was commercialized in 2003 in the Americas. Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) susceptibility to Cry1F was monitored annually across several regions in Argentina using diagnostic concentration bioassays. Reduced performance of TC1507 maize against S. frugiperda was reported in 2013. A resistant population was established in the laboratory and the dominance of Cry1F resistance was characterized...
October 26, 2017: Pest Management Science
Donghai Peng, Xiaoxia Luo, Ni Zhang, Suxia Guo, Jinshui Zheng, Ling Chen, Ming Sun
Pathogen avoidance behavior protects animal hosts against microbial pathogens. Pathogens have evolved specific strategies during coevolution in response to such host defenses. However, these strategies for combatting host avoidance behavioral defenses remain poorly understood. Here, we used Caenorhabditis elegans and its bacterial pathogen Bacillus thuringiensis as a model and determined that small RNA (sRNA)-mediated Cry toxin silencing allowed pathogens to evade host avoidance behavioral defenses. The B. thuringiensis strain YBT-1518, which encodes three nematicidal cry genes, is highly toxic to C...
October 23, 2017: Nucleic Acids Research
Zhen Cao, Wei Zhang, Xiangxue Ning, Baomin Wang, Yunjun Liu, Qing X Li
Bacillus thuringiensis Cry1Ac, Cry1Ia1 and Cry1Ie are δ-endotoxin insecticidal proteins widely implemented in genetically modified organisms (GMO) such as cotton, maize and potato. Western blot assay integrates electrophoresis separation power and antibody high specificity for monitoring specific exogenous proteins expressed in GMO. Procedures for evoking monoclonal antibody (mAb) for Western blot were poorly documented. In the present study, Cry1Ac partially denatured at 100 ℃ for 5 min was used as an immunogen to develop mAbs selectively recognizing a linear epitope of Cry1Ac for Western blot...
October 25, 2017: Journal of Agricultural and Food Chemistry
Ashraf M Ahmed, Hamdy I Hussein, Talat A El-Kersh, Yazeed A Al-Sheikh, Tahany H Ayaad, Hanan A El-Sadawy, Fahd A Al-Mekhlafi, Mohamed S Ibrahim, Jameel Al-Tamimi, Fahd A Nasr
BACKGROUND: The incidence of mosquito-borne diseases and the resistance of mosquitoes to conventional pesticides have recently caused a panic to the authorities in the endemic countries. This study was conducted to identify native larvicidal biopesticides against Culex pipiens for utilization in the battle against mosquito-borne diseases. METHODS: Larvicidal activities of new indigenous Bacillus thuringiensis isolates and crude toxin complexes (TCs) of two nematode bacterial-symbionts, Photorhabdus luminescens akhurstii (HRM1) and Ph...
June 2017: Journal of Arthropod-borne Diseases
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