FIG 2 .

The seven samples of strain C6706 are transformation variable. The seven representatives of strain C6706 (and strain A1552 as a control) were grown on chitin flakes and scored for natural transformability. The data represent the average transformation frequencies of at least three biological replicates (±SD), and the dashed line shows the value for the A1552 control strain. If no transformants were recovered in a subset of the independent experiments, the detection limit value was used for calculations (indicated by the white exclamation mark). Statistically significant differences between the results from the different C6706 strains and the A1552 control strain were determined by Student’s t test (*, P < 0.05; **, P < 0.01; n.s., not significant).