嗜热脂肪芽孢杆菌质粒的分离

Isolation of Plasmids from Bacillus sterothermophilus

从堆肥和污泥中分离到一批抗药性高温细菌,经电泳检查,发现6株高温细菌细胞中有质粒存在。其中,嗜热脂肪芽孢杆菌T653的细胞DNA提取液电泳图谱上,有三条非染色体DNA条带,用电镜直接观察,证明它们是T653细胞中的三个质粒。测得两个较小质粒的分子量分别为3.6×10~6和45×10~6道尔顿。研究了嗜热脂肪芽孢杆的T653的温度生长条件与其细胞中质粒的关系。T653细胞中三个质粒的明确功能有待进一步探讨。

Ninety-seven antibiotic resistance strains of thermophilic bacteria isolated from compost and mud were examined for the presence of plasmids by agarose-gel electrophoresis. Six of the 97 strains tested,T525,T586, T653,TG36,T655 and T632 were shown to carry plasmid DNA. Electrophoresis and electron microscopic studies revealed that Bacillus sterothermophilus T653 carried three kinds of plasmids, pFD 204-1 with molecular weight of 3.6 megadaltons, pFD204-2 with molecular weight of 45 megadaltons and pFD204-3. It is the first case so far to find as many as three kinds of plasmids in thermophilic bacterial cells. We have investigated the relation between the presence of plasmid and the temperature condition of growth. The function of the three plasmids are unknown.