Purification and Properties of an Insecticidal Metalloprotease Produced by Photorhabdus luminescens Strain 0805-P5G,the Entomopathogenic Nematode Symbiont

A total of 13 Photorhabdus luminescens strains were screened for proteolytic activity. The P. luminescens strain 0805-P5G had the highest activity on both skim milk and gelatin plates. The protease was purified to electrophoretical homogeneity by using a two-step column chromatographic procedure. It had a molecular weight of 51.8 kDa, as determined by MALDI-TOF mass spectrometry. The optimum pH, temperature, as well as pH and thermal stabilities were 8, 60 °C, 5–10, and 14–60 °C, respectively. It was completely inhibited by EDTA and 1,10-phenanthroline. Bioassay of the purified protease against Galleria mellonella by injection showed high insecticidal activity. The protease also showed high oral toxicity to the diamondback moth (Plutella xylostella) of a Taiwan field-collected strain, but low toxicity to an American strain. To our knowledge, this is the first report to demonstrate that the purified protease of P. luminescens has direct toxicity to P. xylostella and biopesticide potentiality.     

Synthesis,insecticidal activities and DFT study of pyrimidin-4-amine derivatives containing the 1,2,4-oxadiazole motif

Twenty six novel pyrimidin-4-amine derivatives containing the 1,2,4-oxadiazole motif were synthesized. Their chemical structures were confirmed by ¹H nuclear magnetic resonance (NMR), ¹³C NMR, and high-resolution mass spectrography. The insecticidal activity results indicated that some of them possessed excellent insecticidal activity (100%) against Mythimna separate, especially for compounds 6d, 6f, 6o, 6w, 6y and 6z. These compounds exhibited no activity against the insects Aphis medicagini and Tetranychus cinnabarinus. The structure- insecticidal activity relationships are discussed. Density functional theory analysis can potentially be used to design more active compounds. These results provide useful insecticide design information for further optimization.     

Enhancement of Prodigiosin Production by Serratia marcescens TKU011 and Its Insecticidal Activity Relative to Food Colorants

Prodigiosin (PG) has been reported to have various biological activities. With the aim of increasing Serratia marcescens TKU011 PG production on squid pen powder (SPP)‐containing medium, the effects of phosphate and ferrous ion supplementation, autoclave treatment, and aeration were studied. Autoclave treatment showed positive results for PG productivity (2.48 mg/mL), which increased 2.5‐fold when the organism was incubated in 50 mL of 40‐min autoclaved medium in a baffle‐based flask (250 mL) containing 1.5% SPP at 30 °C for 1 day and then at 25 °C for 2 additional days. Furthermore, the use of pigments including PG and the food colorants Allura Red AC (R40) and Tartrazine (Y4) as insecticides was also investigated. The lethal concentrations causing 50% Drosophila larval mortality (LC50) of PG, Y4, and R40 using a 5‐d exposure period were 230, 449, and 30000 ppm, respectively. The results indicated that the biopigment PG and the food colorant Y4 were potentially toxic to Drosophila larvae.     

两段杨树叶绿体DNA片段的克隆及叶绿体定点转化载体的构建

利用PCR方法,从毛白杨（Populus tomentosa C.）叶绿体基因组中克隆了1．7kb和1．6kb的相邻DNA片段,对其进行序列分析表明,扩增片段分别具有1766个和1601个核苷酸,前者包括3′rps12,rps7基因的编码区及其边界序列,后者包含ndhB基因的第一外显子和内含子。本文还构建了杨树这两个片段的限制酶切图谱,并以这两个相邻片段为同源重组片段,分别将绿色荧光蛋白（GFP）基因和苏云金芽孢杆菌杀虫蛋白（Bt）基因,及其原核表达框插入其间,构建了杨树叶绿体定点转化载体pPZG和pPZB。这两个特异性载体将定位整合到杨树叶绿体基因组中反向重复区的rps7和ndhB基因的间隔区,并高效表达GFP和Bt基因。迄今为止,本文所报道的内容在国内、外尚属首次。     

微生物源杀虫蛋白的多样性分析

虫害一直是危害农林业最严重的问题之一,给我国第一产业带来极大经济损失.长久以来,使用化学杀虫剂防治虫害已经导致环境污染、昆虫抗性等诸多问题的产生,因此近年来,关于具有广谱、高效、低毒等优点的生物农药的研究与应用不断增加.杀虫蛋白,特别是微生物源杀虫蛋白,作为生物农药的重要分支,因其优秀的杀虫潜力,不断被开发应用.对目前...     

智能LED杀虫灯控制系统的设计

为了提高杀虫灯的杀虫效率,设计了基于单片机控制不同光色LED频闪引诱害虫的智能控制系统。硬件设计采用单片机STC89C52RC驱动白、黄、绿、蓝四种光色的LED频闪发光,并利用高压电网灭杀害虫;通过光敏传感器和湿度检测装置感知光照强度和湿度,控制LED和高压电网工作;软件设计采用C语言编制控制程序,实现对LED闪烁频率的控制及其他控制功能。仿真与模拟实验结果表明控制系统的正确性,为杀虫灯的研发提供了一种新思路。     

三氟苯嘧啶的合成与杀虫活性研究

三氟苯嘧啶为杜邦公司开发的新型介离子类杀虫剂。以2-氨基吡啶、间三氟甲基苯乙酸等为起始原料,经过6步反应合成三氟苯嘧啶。目标化合物结构经1H NMR确证。杀虫活性测试结果表明:三氟苯嘧啶对小菜蛾、黏虫、桃蚜均具有一定的活性。在100 mg/L质量浓度下,三氟苯嘧啶对桃蚜的致死率达到89.1%。     

山葵的风味物质及其抗菌杀虫作用

山葵属十字花科山嵛菜属多年生宿根性草本植物。在日本做为生鱼片必用的调料。探讨了山葵的风味物质性质和抗菌杀虫作用，为生产加工和进一步开发这一资源提供参考。     

苯并三嗪酮-3-胺衍生物的合成与杀虫活性研究

设计并合成了10个苯并三嗪酮-3-胺类化合物,其化学结构经1H NMR和MS分析确证。初步生物活性测试表明:该类化合物具有杀虫活性,如在500 mg/L浓度下,化合物4c、4d和7c对粘虫(Mythimna separate)的活性达到80%以上;在500 mg/L浓度下,化合物7d对蚜虫(Aphis fabae)的活性达到80%以上,对螨虫棉红蜘蛛(Tetranchus urticae)的活性达到70%以上。     

龙须菜挥发油的提取及抗菌抗虫活性研究

分别采用直接水蒸气蒸馏法和溶剂提取-水蒸气蒸馏法提取龙须菜(Gracilaria lemaneiformis)挥发油,并进行气相色谱-质谱法(GC-MS)分析和抗菌抗虫活性研究。结果显示:相比于直接水蒸气蒸馏法,溶剂提取-水蒸气蒸馏法提取的龙须菜挥发油中气味阈值较低的醛类成分相对含量低至0.20%,而营养保健价值高的羧酸及酯类含量达到21.54%。龙须菜挥发油对大肠杆菌O157(Escherichia coli O157)、金黄色葡萄球菌(Staphylococcus aureus)、沙门氏菌(Salmonella enterica)、单增李斯特菌(Listeria monocytogenes)和副溶血性弧菌(Vibrio parahemolyticus)5种常见致病菌均有一定的抗菌活性;溶剂提取-水蒸气蒸馏法和直接水蒸气蒸馏法提取的龙须菜挥发油对卤虫的半数致死量(LD50)分别为0.126,0.162mg/mL。