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Abstract:
Transformation systems involving two types of transformable mutants of Bacillus licheniformis 9945A were compared. Each system required its specific growth medium but a single transformation medium could be used for both. Cells from a culture of optimum age developed competence during incubation in a completely synthetic transformation medium. With each system 3 to 5% of the recipient cells were transformed upon exposure to wild-type DNA for 2 to 3 hours. When competent cells were exposed to DNA for 30 minutes, 1 to 2% of them were transformed. The data are interpreted to mean that cells were heterogeneous with respect to development of competence, and when properly grown cells were incubated in transformation medium, some of them gained competence while others lost it. If DNA was present during the entire period, the cells were transformed as they became competent and the transformants accumulated. However, during any short period of exposure to DNA only those cells that were competent at the time were potential transformants. The high frequencies of transformation obtained in these studies made it feasible to prepare marked strains by transforming markers into recipient cells. These experiments demonstrated that the characteristics of the two transformation systems could not be attributed to specific nutritional markers. Presumably each of the two series of highly transformable auxotrophic mutants also carried at least one other mutation that resulted in development of competence under the specific conditions.
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Technical manuscript |
| Pages: |
23 |
| Report Date: |
NOV 1965 |
| Report Number: |
0555574 |
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Keywords relating to this report:
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