An attempt has been made to develop the genetics of Micrococcus radiodurans by analysing transformation and conjugation processes. The nature of the transformation process in M. radiodurans was studied by investigating the effect of various factors on the efficiency of transformations. M. radiodurans can be transformed by exogenous DNA at a frequency of 10 without special treatment. The presence of glucose or amino acids during growth or transformation had no significant effect on the frequency. Treatment of recipient cells with calcium chloride at the optimum concentration of 30 mM increased the frequency of transformation up to 10,000-fold for some markers, e.g. rifampicin resistance. Magnesium and strontium ions could not replace calcium while sine ions completely inhibited transformation. The efficiency of transformation was also affected by the pH, pH 7.0 being the most effective with CaCl-treated cells. The minimum time required for phenotypic expression varied wiith different markers, e.g. for acriflavin resistance and streptomycin resistance it was 35 and 170 minutes respectively. To obtain the maximum number of transformants further incubation was necessary before the addition of antibiotics. This time also varied for different markers. The high frequency of transformation obtained using the new protocol enabled studies on genetic linkage to be started.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:662969 |
| Date | January 1978 |
| Creators | Tirgari, Simin |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13138 |
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