苏云金杆菌--毒素及其应用（ppt 111页）

苏云金杆菌（ BT） 毒素及其应用1 What is Bacillus thuringiensis l1 苏云金杆菌是什么？A rod-shaped (1.0-1.2 by 3-5 micron), gram-positive, facultative anaerobic, spore forming bacteriuml杆状，大小为 1.0-1.2 3-5 m， 革兰氏 阳性，兼性嫌氧，产孢的细菌菌体照片A facultative pathogen of some insect species commonly used as a biopesticide.l一些昆虫的兼性病原物，常用作生物杀虫剂。More than 150 insects belonging to the orders Lepidoptera, Diptera, and Coleoptera are known to be susceptible to Bt. To be effective, Bt must be eaten by insects during their feeding stage of development, when they are larvae. Bt is ineffective against adult insects. l 150种以上属于鳞翅目、双翅目、和鞘翅目的昆虫易感染 Bt。 Bt要昆虫幼虫取食后才会发生效力，对成虫无效 。During sporulation, it produces protein inclusions (parasporal inclusions) adjacent to the endosporel产 芽孢期间， BT在邻近芽孢处形成蛋白内含体。Electron Micrograph of a Sporulating Bt Cell l 产孢 BT菌体的电子显微照片The parasporal inclusions consist of one or more insecticidal proteins in the form of a crystal or crystal-complex. These insecticidal proteins are commonly known as Insecticidal Crystal Proteins (ICP) or delta endotoxin. The primary insecticidal activity of Bt is due to ICP. It is the active ingredient of most (90%) of the microbial insecticides produced in the world. l 这种类孢内含体由 1-2个蛋白晶体或晶体复合物组成。这些杀虫蛋白通称为杀虫晶体蛋白（ ICP）或 -蛋白。 BT的主要杀虫活性是由于 ICP。是世界上生产的大多数微生物杀虫剂（ 90%）的活性成分。The endospore, highly resistant to environmental stress, provides a mechanism for long-term survival of Bt. l内 孢子高抗环境压力，提供了BT长期生存的机制。芽孢Besides ICP and endospore, some Bt subspecies produce Beta Exotoxin which is toxic to all forms of life including humansl除 ICP和内孢子（即芽孢）外，有些 BT还产生 外毒素，这些毒素对所有生物包括人类都有毒害作用。An insect must have a strongly alkaline mid-gut, specific proteolytic enzymes and suitable tissue receptor-sites, to be susceptible. lBT要起杀虫作用，必须满足 3个条件，一是昆虫中肠液呈碱性；二是有特定的蛋白酶，三是有适合的组织受体位点。Bt can be produced easily on solid media or under submerged fermentation conditions - a key factor in its successful development as a biopesticide. l BT容易在固体培养料上生产，也可以液体发酵生产，后一性能是作为杀虫剂成功开发的关键因子 。Biotechnology and advances in the fermentation industry over the past three decades have improved the quality of Bt products. l过去 30年在发酵工业和生物技术上取得的进展促进了 BT产品的质量Bt is key source of genes for transgenic expression to provide pest resistance in plants. BT是转基因表达，为植物提供抗虫性的关键基因来源。转基因玉米转基因棉花生测2 History 2 研发历史Discovered by Dr. Ishiwatari (a Japanese bacteriologist) in 1901 in silkworm farms as the causal agent of the sotto bacillus disease. l日本细菌学家 Ishiwatari博士 1901年于一个蚕场发现 BT是蚕 sotto 芽孢菌病的病原。蚕Insecticidal activity was discovered in 1911 by Berliner (Germany) He named it Bacillus thuringiensis, after the German town Thuringia where the moth was found. l德国 的 Berliner 于 1911年发现 BT有杀虫（地中海粉蛾）活性。并根据发现地德国小镇 Thuringia命名。Existance of parasporal inclusions in Bt was noted in 1915 by Berliner. lBerliner还于 1915年发现 BT类似于孢子的内含体的存在。 First time used as insecticides in late1920s1920年代后期首次用作杀虫剂。Spore-based formulations were commercially available in late 1950sl1950年代后期市场上有孢子态的制剂销售。First registered as a pesticides in the U.S. in 1961l1961年在美国作为杀虫剂首次登记。In 1960s, experiments with spore-based formulations produced erratic (inconsistent) resultsl 1960年代，用孢子态制剂做的试验得到的药效结果不一。By the 1970s it was demonstrated that the primary insecticidal activity against lepidoteran insects was due to delta (d) endotoxinsl 到 1970年代才明白对鳞翅目害虫的主要杀虫活性是由于 -毒素。Until 1977, only 13 Bt subspecies had been described; all were toxic to lepidopteran larvae only. l 1977年以前只发