Bacillus Thuringiensis

Bacillus thuringiensis (Bt) has been used as a biopesticide in agriculture, forestry and mosquito control because of its advantages of specific toxicity against target insects, lack of polluting residues and safety to non-target organisms. The insecticidal properties of this bacterium are due to insecticidal proteins produced during sporulation. Despite these ecological benefits, the use of Bt biopesticides has lagged behind the synthetic chemicals. Genetic improvement of Bt natural strains, in particular Bt recombination, offers a promising means of improving efficacy and cost-effectiveness of Bt-based bioinsecticide products to develop new biotechnological applications. On the other hand, the different Bacillus species have important biotechnological applications; one of them is carried out by producing secondary metabolites, which are the study object of natural product chemistry. The amazing structural variability of these compounds has attracted the curiosity of chemists and the biological activities possessed by natural products have inspired the pharmaceutical industry to search for lead structures in microbial extracts. Screening of microbial extracts reveals the large structural diversity of natural compounds with broad biological activities, such as antimicrobial, antiviral, immunosuppressive, and antitumor activities that enable the bacterium to survive in its natural environment. These findings widen the target range of Bacillus spp., in special B. thuringiensis, besides insecticidal activity and help people to better understand its role in soil ecosystem.

"This monograph contains four chapters, each of which provides a different perspective on biopesticides. Chapter One concerns the use of biopesticides in sustainable agriculture, including the interactions between biopesticides and chemical pesticides, production issues, and opportunities for future research. Chapter Two describes the bottom-up approach for using Bacillus thuringiensis (Bt) as a biopesticide and for enhancing host plant resistance against major foliage feeders through deployment of suitable cry genes. Chapter Three reviews strategies for mitigating the spread of Bt resistance and improving insecticidal activity against Bt-susceptible pests. Lastly, Chapter Four aims to revise, debate, and evaluate the effects of Bt as phosphate solubilizing and phosphorus uptake by plant establishment"--

In Chapter One, André L de A Melo, Ph.D. discusses the spore-forming bacterium Bacillus thuringiensis and its uses as a bio-insecticide, also touching on ways to combat insect resistance. In Chapter Two, Karim Ennouri proposes the bacterium Bacillus thuringiensis as an important biopesticide because of the entomopathogenic effect of delta-endtoxins as well as its efficiency against insects resistant to chemical insecticides. In conclusion, Rafael C Lajmanovich, Candela S Martinuzzi, Carlina Colussi, Paola M Peltzer, Agustín Bassó, Andrés M Attademo, and Lucila M Curi present a study exploring the impact of a GM Bt-soybean-based diet, as opposed to a lettuce diet, on tadpoles.

Make the right decisions when it comes to pest control in agriculture! Bacillus thuringiensis: A Cornerstone of Modern Agriculture explores the impact that one of the most prominent biologically based pesticides has had on pest control technology—and the issues that surround its use. The book examines the development, use, and management of technologies derived from Bacillus thuringiensis (Bt), addressing the health, economic, environmental, and social concerns generated by the deployment of genetically engineered crops. Authors representing a diverse cross section of the international scientific community contribute review articles and research findings that address the use of Bt in microbial formulations and transgenic crops, technological advances in the genetic engineering of plants, advances in methodologies, and improved agricultural practices and productivity through the use of Bt cotton. Bacillus thuringiensis: A Cornerstone of Modern Agriculture examines the vital issues surrounding this Gram-positive bacterium. Contributors from academia, government, and industry address the safety of Bt for human consumption, its effects on non-target organisms, the role of microbial Bt products in crop production in the United States, and the utility and management of transgenic plants. The book also explores: engineering Bt transgenic rice for insect pest protection the Bt potato in developing countries Bt expression in sugarcane and cauliflower a comparative analysis of Bt cotton in Argentina the ecological impact, gene expression, and current resistance management requirements of Bt cotton in the United States and much more! Bacillus thuringiensis: A Cornerstone of Modern Agriculture is an essential resource for advanced students and technical specialists working in agriculture, biotechnology, entomology, pest management, and crop sciences. Stakeholders will also find it invaluable in regulatory decision making about genetically engineered crops, pesticide use, and crop protection.

The challenge of bacillus thuringiensis. Historiacal overview: from discovery until 1980s. The 1980s: a decade of change. The future challenge. Diversity of bacillus thuringiensis toxins and genes. Diversity of B. thuringiensis strains and toxins. Localization and molecular organization of the toxin genes. The crystal protein genes and products. Regulation of crystal synthesis. Domain-function studies of bacillus thuringiensis crystal proteins: a genetic approach. Mode of action structural features of crystal proteins. Crystal protein mutants. Crystal protein hybrids. Transgenic bacteria, viruses, algae and other microorganisms as bacillus thuringiensis toxin delivery systems. Conventional B. thuringiensis products: do they nedd to be improved?. The use of transgenic microorganisms to improve insect host range. Improving foliar acticity and delivery. Improving aquatic activity and delivery. Improving soil activity and delivery. Issues in the development of transgenic microorganisms. The engineering of plants to express bacillus thuringiensis -endotoxins. Expression of -endotoxins in dicotyledons. Expression of -endotoxins in monocotyledons. Quantification of -endotoxins expression in planta. Enhancement of -endotoxin expression in planta. Endophyte expression of -endotoxin genes in plants. Control of lepidopteran pests with bacillus thuringiensis. Conventional and genetically engineered b. thuringiensis. Products. Microbial specificity of b. thuringiensis in lepidopteran pests. Entomological aspects of lepidopteran pest control with B. thuringiensis. Integration of B. thuringiensis in lepidopteran pest control strategies. Use of bacillus thuringiensis israelensis against mosquitoes and blackflies. Properties of B. thuringiensis israelensis. Factors influencing the efficacy of B. thuringiensis israelensis treatments. Organization of mosquito control programmes. Successful control programmes using B. thuringiesis israelensis. Future prospects for the use of B. thuringiensis israelensis. Control of coleopteran pests by bacillus thuringiensis. B. thuringiensis tenebrionis products and their registration. Characterization of B. thuringiensis tenebrionis and other coleopteran-active subspecies. Host range of B. thuringiensis tenebrionis and susceptibility levels of some pest species. The impact of B. thuringiensis tenebrionis on nor-target animals. Control of coleoptera by -exotoxin. Field trials with B. thuringiensis tenebrionis. Future prospects. Bacillus thuringiensis in the environment: ecology and risk assessment. Role in the environment. Risk assessment. Resistance to bacillus thuringiensis and resistance management. Field resistance development to B. thuringiensis. Laboratory selection for resistance. Cross resistance of B. thuringiensis to chemicals and other B. thuringiensis strains. Genetics of resistance. Mechanisms of resistance. Strategies for delaying resistance development. The use of bacillus thuringiensis in developing countries. History and usage of B. thuringiensis in developing nations. Strain survey and selection. Production levels and costs. Inexpensive and local fermentation media. Low technology fermentation procedures. Stability and formulation. Field application. Further development of B. thuringiensis. Future role for B. thuringiensis in developing countries. Production of bacillus thuringiensis insecticides for experimental and commercial uses. Optimization of production methods. Production methods for B. thuringiensis. Quality control.