[Effect of calcium and magnesium ions on different stages of genetic transformation in Bacillus subtilis]

Optimal concentrations of magnesium and calcium ions under their combined effect on genetic transformation in Bacillus suttilis are 2 - 10(-2) M and 4 - 10(-2) M respectively. The same concentrations are optimal under the effect of each cation clone. Magnesium ions are efficient during irreversible DNA binding. In the presence of magnesium ions calcium ions stimulate more late stages of transformation. The greatest efficiency of transformation is shown in consecutive effect of magnesium ions at early stages of transformation and of calcium ions at late transformation stages. This suggests that magnesium and calcium ions stimulate the activity of nuclease, taking part at early and late transformation stages.