筛选的苏云金芽孢杆菌野生菌株 1 5A3经鉴定属血清H 2 1型科默尔亚种。用PCR及RFLP方法对其cry1类基因分析证明其含有cry1Aa,cry1Ac,cry1Ca,cry1D ,cry1I及cry2六种cry基因 ,其cry1A基因N末端 1 45kb片段与已发表的序列有差异。表达晶体蛋白质的分子量分别为 1 3 0 ,79,70 ,6 5 ,5 1和 45kD。对家蝇致畸实验证明其不含 β 外毒素。发酵液对棉铃虫 ,甜菜夜蛾 ,小菜蛾及美国白蛾均具较高的毒力。证明野生的苏云金芽孢杆菌资源中也有具国外工程菌所特有的高效杀虫晶体蛋白基因组合的优良菌株 The selected Bacillus thuringiensis strain 1 5A3 was identified as a serotype H 2 1 strain Commercia. Cry1Aa, cry1Ac, cry1Ca, cry1D, cry1I and cry2 cry genes were identified by PCR and RFLP. The cry1A gene at the N-terminal 1 45kb fragment was different from the published sequences. The molecular weights of the expressed crystal proteins were 130, 79, 70, 65, 51 and 45 kD, respectively. Musca domestica test teratogenicity proved that it does not contain beta exotoxin. Fermentation broth had higher toxicity to cotton bollworm, beet armyworm, diamondback moth and white ladybug. It is proved that the wild Bacillus thuringiensis resources also have excellent strains that are highly effective insecticidal crystal protein gene combinations unique to foreign engineering bacteria