FIG. 3.

Ability of 1021-derived mutants to grow in MM with 0.5 M NaCl added at pH 7 (a) and pH 6.5 (b). In each row, drops contain approximately the number of CFU indicated at the left. A representative example of at least two experiments is shown. Pictures were taken after 6 to 8 days of incubation under the indicated conditions.