Viability and morphology of <i>V</i>. <i>cholerae</i> mutants after 48 hours at alkaline pH.

<p>Fluorescent (F) and differential interference contrast (DIC) images of O395 Δ<i>toxR</i>, Δ<i>rseP</i>, Δ<i>rseP</i>Δ<i>toxR</i>, Δ<i>rpoE</i> or Δ<i>rpoE</i>Δ<i>toxR</i>, <i>toxR248</i>, <i>toxR248</i>Δ<i>rseP</i>, <i>toxR248</i>Δ<i>rpoE</i>, and <i>toxR-phoA</i> grown for 48 hours in LB starting pH 9.3 (unbuffered). The cells were observed after treatment with the LIVE/DEAD BacLight Bacterial Viability and Counting Kit. Viable and culturable cells appear green and elongated; viable but dormant cells appear green and round; dead cells appear red and round.