Abstract
(Synopsis) A simple method for the extraction and partial purification of the chromsomal DNA from a thermophilic bacterium, PS3, is described. Actively growing thermophilic bacerium PS3 was lysed by sodium dodesyl sulfate (SDS) and then the proteins were eliminated by the perchloric acid and chloroform treatment. The resulting partially purified DNA was precipitated by ethanol used for genetic transformation of PS3. A cadmium-resistant strain (CDRI) was isolated from PS3 by a treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). A partially purified DNA were also prepared from the CDRI cells. Then this DNA was added to the proliferating PS3 cells (cadmium sensitive cells). The cadmium-resistant cells were obtained at a frequency of 10^3 cell/μg DNA. This bacteria did not require chemical treatment to induce competence, although high-frequent transformation required the addition of Ca^<2+>. Transformation frequency was greatly reduced by the addition of EDTA. A further simplified method for the genetic transformatin of PS3 on solid agar medium is also described. The application of these methods to the biology education in high school is also discussed.
