• 作者： 翟建富; 楊益明
• 作者服務機構： 國立陽明醫學院生化科
• 中文摘要： 從百多株臺灣土壤分離出來的蘇力菌（Bacillus thuringiensis)中，在對比顯微鏡觀察下，發現可產生三種不同類型的晶體蛋白，而分析其質體圖譜時，則發現共有14類不同的類型，這些質體的大小從數個kb到250kb不等。若以晶體的形狀，以及質體與晶體蛋白的圖譜作比較，我們發現其中87％的分離菌種與已發表過的蘇力菌有很大的差異；其餘的10％與3％則分別與Bt var.kurstaki HD-1和Bt var. israelensis類似。在活體毒性測驗中發現，從Bt新種分離出來的晶體蛋白，大部份都能有效的殺害雙翅目和鱗翅目等昆蟲的幼蟲，其中第82和第96號的分離品種，其晶體蛋白對於煙草芽蟲的毒性還比Bt var. kurstaki HD-1強很多。再以Bt var. aizawai的晶體蛋白基因作為探針，發現大部份的Bt新種中，至少都有一質體能與其反應，同時也還發現有一約1Okb的質體與探針有反應，這可能是現今第一個例子，證實殺蟲晶體蛋白基因也可能存在於分子量較小的質體上。
• 英文摘要： Over 100 Bacillus thuringiensis (Bt) isolates which produced phase bright inclusions have been is-olated from soil samples from different areas in Taiwan. Three types of crystal proteins were visualizedby phase contrast microscopy. Among these isolates, only 14 different types of plasmid profiles havebeen observed. They all possess a variety of plasmids ranging from a few kb to around 250 kb in size. Withrespect to the crystal protein profiles, the plasmid profiles, and the shapes of crystal proteins, we foundthat the majority of our isolates (87%) were different from most of the known Bt strains. Our other twotypes of isolates（10 and 3%) resembled Bt var. kurstaki HD1 and Bt var. israelensis, respectively. Mostof our isolates were active against Bombyx mori (Lepidoptera) and Aedes aegypti (Diptera). Most in-terestingly, two of our isolates, Nos. 82 and 96, were found highly toxic to Heliothis virescens, even com-pared with the standard strain, Bt var. kurstaki HD1. Using insecticidal crystal protein (ICP) gene probefrom Bt var. aizawai HD-133 to probe the total DNA of our isolates, we observed that at least one plasmidfrom each of the tested strains reacted with the probe. A 10 kb plasmid from some of our isolates hybri-dized with the probe. This probably is the first evidence demonstrating that the ICP gene sequence can befound in a low molecular weight plasmid.
• 中文關鍵字： Bacillus thuringiensis; plasmid; insecticidal protein; toxicity test
• 英文關鍵字： --