pGSP12-stimulated transformation of B. subtilis ATCC 6633 and ATCC 21332. Growth curves for B. subtilis ATCC 6633, with (▴/▵) and without pGSP12 (▪/□), and B. subtilis ATCC 21332, with (•/○) and without (⧫/⋄) pGSP12, are presented in the graph. Closed symbols refer to growth in minimal medium, and open symbols refer to growth in rich medium. The time scale indicates hours before and after the transition from the exponential to the stationary growth phase, and arrows indicate the time of transformation. The numbers of transformants obtained are shown in the table.