【摘要】 采用不同照射时间的紫外光 (UV)对 1株野生型Bt菌株及 3株Bt菌株Bt0 0 1、Bt2 0 0、Bt0 87进行照射处理后再置于双碟上培养 16h ,结果表明 ,Bt野生菌株在UV处理 3min后已基本全部失活 ,而Bt0 0 1、Bt2 0 0、Bt0 87在UV处理 8min后仍有活性。从UV处理时间的长短及平板上出现菌落数的多少得知 ,尽管菌株Bt0 0 1、Bt2 0 0、Bt0 87对UV的抗性都比野生Bt菌株强得多 ,但并不相等。其中 ,Bt2 0 0相对弱些 ,UV处理 9min后已无菌落 ;Bt0 87最弱 ,UV处理 8min后已无菌落 ;而菌株Bt0 0 1对UV的抗性最强 ,UV处理 13min后仍有菌落出现。这说明不同的Bt菌株 ,其遗传背景是不同的。另外 ,Bt0 0 1经紫外线照射 9min ,培养 16h后发现有 9个菌落发生明显的变异 ,菌落呈棕黄色 ,菌落明显比原始菌落小。涂片 ,油镜下观察其菌体要比原始菌体小 ,此为明显发生突变的菌株更多还原

【Abstract】 One wild Bacillus thuringiensis strain which was i solated from the soil with the method of Sodium acetate-Antibiotics and three strains such as Bt00l? Bt200?Bt087 were cultured for l6 hours on solid media after dealing with UV lig ht. The results indicated that the wild-type Bt was dead after lighting by UV on ly for 3 minutes,and Bt001?Bt200?Bt087 were active after lighting by UV for 8 minutes. Although their resistance to UV of Bt001?Bt200?Bt087 is greatly supe rior to the wild-type Bt,they are not equal. Bt200 is relatively weak,its colon ies disappeared after lighting by UV for 9minutes,Bt087 is weakest, its colonie s disappeared after lighting by UV for 8 minutes,Bt001 is strongest among them ,its colonies can still appear after lighting by UV for l3 minutes.In addition ,one mutant was discovered from the strain Bt001 lit by UV for 9 minutes.更多还原