FIG. 1.

Transformation of relaxed (relA) and stringent (relA⁺) strains. B. subtilis strains 61884 (stringent) and 61883 (relaxed) were grown in TF medium containing 20 mM aspartate. Samples were taken at the indicated times to determine culture density (A₆₅₀) and transformation efficiency (as discussed in Materials and Methods). The transformation efficiency is expressed as the number of asp⁺ transformants generated after exposure to chromosomal DNA from strain 168 (1 μg/ml) for 30 min. Growth (open symbols) and transformation efficiency (closed symbols) of strain 61883 (circles) and strain 61884 (squares) are shown.