共查询到19条相似文献,搜索用时 585 毫秒
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苏云金素发酵培养基的优化设计 总被引:2,自引:0,他引:2
采用Plackett-Burman设计对出发培养基各种成分影响苏云金芽孢杆菌中华亚种CT43发酵合成苏云金素的效应进行评价,筛选出有显著影响效应的因素为葡萄糖和黄豆饼粉。利用最陡爬坡路径试验逼近最大苏云金素产出区域,找到后续试验中心点。综合中心组合设计和响应面分析法确定显著因素的最佳浓度。优化后培养基组成为(g/L):葡萄糖22.8g、黄豆饼粉32.5g、酵母抽提物3.0g、蛋白胨4.5g、玉米浆3.0g、KH2PO42.0g、MgSO4.7H2O 0.15g、MnSO4.H2O0.02g,苏云金素产量可达3.2g/L,比出发培养基提高2倍以上。 相似文献
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为了提高苏云金芽胞杆菌的芽胞产量,应用响应面设计对苏云金芽胞杆菌(Bacillus thuringiensis,Bt)JQD117进行发酵培养基和摇瓶发酵条件的优化。本研究在单因素试验基础上,采用响应面试验设计方法优化培养基组分和发酵条件参数。最佳发酵培养基为棉籽饼粉2.00%,大豆饼粉1.00%,酵母粉1.50%,可溶性淀粉2.00%,CaCO3 0.30%,MnSO4 0.04%,MgSO4 0.18%,K2HPO4 0.04%;最佳发酵条件:接种量3%、装液量60 mL、温度30℃、转速150 r/min、初始pH 7.5。在最佳发酵条件下理论活芽胞产量可以达到6.75×109个/mL,试验验证后实际活芽胞产量为5.97×109个/mL。运用响应面法对Bt的发酵条件进行优化,获得了提高芽胞产量的关键参数,为该菌株产业化、规模化应用奠定了基础,为韭菜迟眼蕈蚊的绿色防控和蔬菜的安全生产提供了理论基础。 相似文献
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枯草芽孢杆菌发酵培养基的优化 总被引:1,自引:0,他引:1
枯草芽孢杆菌(Bacillus subtilis)B908菌株是中国农业大学植物病害生物防治研究室从水稻根际土壤中分离获得的对水稻纹枯病有明显防治效果的有益菌株,应用前景广阔。本项研究的目的是通过优化发酵培养基的配方,提高该菌株发酵液的含菌量。发酵培养基配方是影响微生物发酵的重要因素之一。大量研究结果表明,不同细菌对各种营养物质的需求量不同。本项研究收集到应用于芽孢杆菌发酵的培养基配方20余种,通过摇床培养筛选出较适宜于枯草芽孢杆菌菌株B908发酵的培养基配方:玉米粉1.0%,葡萄糖0.5%,豆饼粉 相似文献
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苏云金杆菌高效培养基优选模型的研究 总被引:10,自引:0,他引:10
本研究设计一套“正交试验-浓度加倍-生物测定”新的培养基配方优选模型,获得了理相怕高效培养基配方。采用79007号菌株和5号配方,用7吨发酵罐进行了试验,平均发酵效价达2887×10^3IU/ml。实验结果表明,该方法是苏云金杆菌发酵培养基配方优选中十分单,实用,快速瓣新作。 相似文献
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富营养化湖泊中蓝藻爆发已成突出的环境问题。以云南昆明滇池蓝藻新鲜藻泥为培养基,通过接种Bt菌种,测定发酵过程中Bt的活菌数及芽胞数,观察其生长过程中形态变化,同时测定杀虫晶体蛋白产量及杀虫毒力效价,并与常规LB培养基比较,探究了利用蓝藻藻泥培养基接种苏云金芽胞杆菌(Bt GIM1.32)制备生物源杀虫剂的可行性。结果表明:Bt GIM1.32菌种在新鲜蓝藻培养基中能正常生长并完成芽胞和伴胞晶体的合成;当蓝藻含固率为3%、pH 7、接种活化10 h处于对数生长期的菌种、接种量为2%、培养温度为30℃时,灭菌后直接接种Bt GIM1.32菌株,发酵48 h左右其活菌数可达到相对稳定值(6.79×108CFU/mL),54 h左右芽胞数达到相对稳定值(7.01×108CFU/mL);其130 ku晶体蛋白的质量浓度为4.81 mg/mL,对3龄小菜蛾的致死中浓度(LC50)为0.180μL/mL,毒力效价为1 600.00 IU/μL;发酵性能较常规LB培养基优良。研究表明,蓝藻作为发酵生产生物源农药Bt的培养基具有很好的开发潜力和应用前景。 相似文献
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苏云金芽孢杆菌LSZ9408虫体复壮的研究 总被引:3,自引:0,他引:3
本研究利用敏感寄主小菜蛾Plutella xylostella L.进行苏云金芽孢杆菌Bacillus thuringiensis Berliner LSZ9408的虫体复壮。试验结果表明通过小菜蛾虫体培养1次和2次后, LSZ9408的产晶率由0.0%分别提高至25.8%和39,4%,对小菜蛾72h的毒力由42.7%分别提高至83.4%和100.0%;经过发酵培养基的筛选,培养2代产晶率又可提高至49.7%;经70L发酵罐发酵48h时,活芽孢数可达54.5×108cfu/ml。 相似文献
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试验证明复方青虫菌6号商品制剂在通常稀释1000倍的剂量下(含氯氰菊酯0.5ppm),能100%杀死伪钝绥螨和智利植绥螨。不含氯氰菊酯的青虫菌制剂对两种捕食螨的死亡率分别为1.7%和7.1%。复方制剂1000倍液和500倍液在温室中施药10天后,其残效仍能使智利螨的初孵幼螨死亡率分别达到52.5%和70.7%。用含氯氰菊酯农药0.1ppm的液剂处理感染叶螨的菜豆叶,饲养智利螨雌成螨,产卵量比对照减少80%左右。为避免含有化学农药的生物制剂杀伤天敌的副作用,作者认为生物制剂中以不加化学农药为宜。必要时可根据实际情况,在使用前再加入适量的化学农药。 相似文献
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Bt玉米已在美洲广泛种植20多年,成功控制了欧洲玉米螟Ostrinia nubilalis、草地贪夜蛾Spodoptera frugiperda等玉米重大害虫为害。然而,近年来相继报道在波多黎各、巴西、阿根廷因草地贪夜蛾产生抗性而导致一些Bt玉米抗虫性丧失。尤其是在热带和亚热带地区,多数Bt玉米品种商业化种植仅3年就丧失了对草地贪夜蛾的抗性。本文分析了草地贪夜蛾的生物学和生态学、对Bt杀虫蛋白抗性遗传特征和交互抗性特性、种群抗性基因频率等内因对抗性演化的影响,以及Bt玉米种植的生态环境、耕作栽培制度、Bt玉米种类、抗性治理策略实施情况等外部环境因素对抗性演化的影响。根据我国玉米种植的生态格局,提出了"整体布局,源头治理"的抗性治理对策。即在草地贪夜蛾周年繁殖区要谨慎种植Bt玉米,尤其是避免种植表达Cry1Ab杀虫蛋白的Bt玉米,以避免源头产生抗性而危及温带玉米主产区。遵循差异化(不同杀虫作用机理)选择Bt玉米品种原则,制定精准抗性监测计划,以高剂量-庇护所为抗性治理基本策略,在Bt玉米资源有限的情况下,落实好庇护所尤为重要。 相似文献
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大螟幼虫田间扩散及成虫飞行能力研究 总被引:2,自引:0,他引:2
大螟的抗性演化将成为制约Bt水稻产业化发展的关键因素,为实施预防性的害虫抗性治理策略,明确大螟成、幼虫的运动习性具有非常重要的意义,本文通过田间调查和飞行磨测试的方法研究了大螟幼虫在田间的迁移扩散行为和成虫的飞行能力。结果表明,大螟幼虫在不同水稻穴之间及同一水稻穴内的不同分蘖间均存在频繁的迁移扩散,且其在分蘖期水稻上的迁移扩散能力显著高于孕穗期水稻。在整个幼虫发育过程中,大螟在分蘖期和孕穗期水稻上的平均迁移扩散距离分别为62.29cm和51.02cm,最大扩散距离为120cm。吊飞结果表明,大螟的有效飞行时间为4~5d,能多次飞行,约有75.5%的个体累计飞行距离≤5km。因此,对于幼虫扩散能力相对较强、成虫飞行能力相对较弱、求偶前期相对较短的大螟来说,建议其抗性治理策略应设置为分区种植的庇护所,且庇护所与Bt稻田的距离最好不超过5.0km。 相似文献
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Susan C MacIntosh 《Pest management science》2010,66(1):100-106
BACKGROUND: Growers have enthusiastically embraced crops genetically modified to express Bacillus thuringiensis (Bt) proteins for insect control because they provide excellent protection from key damaging insect pests around the world. Bt crops also offer superior environmental and health benefits while increasing grower income. However, insect resistance development is an important concern for all stakeholders, including growers, technology providers and seed companies that develop these genetically modified crops. Given the marked benefits associated with Bt crops, insect resistance management (IRM) must be a consideration when cultivating these crops. RESULTS: The technical data and practical experience accumulated with Bt crops in many global regions can inform different aspects of resistance management leading to robust, science‐based IRM plans. A range of elements should be considered in assembling any IRM strategy, including: pest biology/ecology, product deployment patterns, local cropping systems, insect susceptibility monitoring, stakeholder/grower communications, and a remedial action plan should resistance develop. Each of these elements is described in more detail, with specific examples of how these elements can be combined and tailored to the local/regional environments and grower practices. CONCLUSION: IRM plans need to be suitable for the given production situation. What works for large monoculture production systems in North America is unlikely to be appropriate for the small, more diverse agriculture of southeast Asia or Africa. Though it is clear that Bt crops impart considerable value to growers, it is also clear that it is in the best interest of all stakeholders to preserve Bt proteins for the long‐term benefits they provide. Copyright © 2009 Society of Chemical Industry 相似文献
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Rosas-García NM 《Pest management science》2006,62(9):855-861
Formulations of Bacillus thuringiensis Berliner (Bt) with insecticidal activity against the sugarcane borer, Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae), were developed and tested under laboratory and field conditions. The formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a Bt var. kurstaki GM-34 strain from a non-sugarcane region as the active ingredient. The spore-crystal complex of this strain was mixed at three different concentrations (30, 70 and 100 g kg(-1)) with the other ingredients. The blends were prepared as spray-dried and granular formulations, and then submitted to laboratory tests with two day old larvae of D. saccharalis and field tests in sugarcane crops with natural sugarcane borer infestation. Spray-dried formulations in laboratory bioassays caused mortality near 100% with all three concentrations, and granular formulations caused mortality around 84%. The field tests showed that spray-dried formulations at 70 and 100 g kg(-1) concentrations were as effective as a commercial bioinsectide (Lepinox), while granular formulations were ineffective. 相似文献
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