Cells overexpressing PhoB adapt to Pi-replete environments by abolishing PhoB expression.

<p>(A) PhoB levels of the adapting culture under the Pi-replete condition. RU1618 (TRC) was induced with 15 µM IPTG to achieve overexpression of PhoB and allowed for adaptation in continuous cultures. (B) PhoB expression in batch cultures from random colonies isolated at different times. Lower case letters indicate genotypes identified in selected colonies that were subjected to sequencing analyses. (C) List of mutations for adapted cells with altered PhoB expression.