氯氰菊酯降解菌Y-3的诱变育种与筛选

以从菠菜叶片内分离到对氯氰菊酯降解率较高的菌株Y-3(Corynebacterium vitarumen)为出发菌,进行化学诱变和紫外诱变.结果显示,DES对菌株Y-3的最佳诱变条件为2%60 min、3%40 min和4%20 min,紫外线对对菌株Y-3的最佳诱变条件为5 cm 8 min、10 cm 20 min和15 cm 30 min.通过诱变与筛选,最终获得13株突变株,与野生菌株对比,7株突变株对氯氰菊酯的降解率有明显的提高,其中有3株突变株具有一定的遗传稳定性.     

Caseous Lymphadenitis in Goats: The Pathogenesis,Incubation Period and Serological Response after Experimental Infection

Twenty goats, in two groups of 10, were injected intradermally with Corynebacterium pseudotuberculosis. The doses of infection were 1×10⁵ and 5×10⁴ colony-forming units (cfu) for groups 1 and 2, respectively. Thereafter, a goat from each group was killed every 2–3 days and examined for gross and microscopic caseous lesions in the draining lymph nodes. Bands or zones of macrophages and polymorphonuclear granulocytes were observed microscopically on the second day of infection in both groups. Gross caseous lesions were observed from days 8 and 9 of infection, respectively. Positive bacterial agglutination test and haemolysis inhibition test titres were detected after 15–17 days and 20–25 days of infection, respectively. These results indicated that caseous lymphadenitis is a subacute disease with an incubation period of 8–9 days, but that it is not detectable serologically until after 15 days of infection.     

谷氨酸棒状杆菌在乙酸盐和葡萄糖基质上的蓝白生长筛选(英文)

在谷氨酸棒状杆菌乙酸盐代谢调控关键酶-异柠檬酸裂解酶aceA基因两段启动子区域后面组装了无启动子的β-半乳糖苷酶报道基因,并且带上四环素抗性标记基因构建了两个检测质粒pROH7 和pROHO.通过该两个质粒转化了谷氨酸棒状杆菌野生型菌株Corynebacterium glutamicum ACTT 14752,分别获得了含有两个检测质粒的两种谷氨酸棒状杆菌,由此建立了谷氨酸棒状杆菌在乙酸盐和葡萄糖基质上的两个蓝白生长筛选系统.结果显示当两种菌株生长在含有葡萄糖的基本培养基上时呈现白色菌落,而生长在含有乙酸盐的基本培养基上时呈现蓝色菌落;其中菌落颜色还随菌株中检测质粒pROH7 和pROHO的不同而呈现淡蓝色和深蓝色的变化.含有检测质粒pROH7 和pROHO菌落的颜色变化反映了细胞在葡萄糖和乙酸盐不同和碳源上的调控状态,该两个质粒在鉴定乙酸盐代谢中的调控变化方面是有积极意义.