Abstract
Bacteria in nature are known to survive for long periods under restricting conditions, mainly by reducing their growth rate and metabolic activity. Here, we uncover a novel strategy utilized by bacterial cells to resist aging by propagating rather than halting division. Bacterial aging was monitored by inspecting colonies of the Gram-positive soil bacterium Bacillus subtilis, which is capable of differentiating into various cell types under nutrient exhaustion. We revealed that after days of incubation, rejuvenating subpopulations, arrayed over the mother colony, emerged. These subpopulations were found to harbor mutations in a variety of genes, restricting the ability of the cells to differentiate. Surprisingly, even mutations that are not classically designated to developmental pathways, concluded in differentiation deficiency, indicating that multiple paths can reach this same outcome. We provide evidence that the evolved mutants continue to divide under conditions that favor entry into quiescence, hence becoming abundant within the aging population. The occurrence of such nondifferentiating mutants could impact bacterial population dynamics in natural niches.
| Original language | American English |
|---|---|
| Article number | e01414-19 |
| Journal | mBio |
| Volume | 10 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1 Sep 2019 |
Bibliographical note
Funding Information:This study was supported by the European Research Council Advanced Grant (339984) and by the Israel Science Foundation grant (774/16) awarded to S.B.-Y. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication. We thank Y. Nevo (The Hebrew University of Jerusalem, Jerusalem, Israel [Hebrew U, IL]) for WGS analysis, N. Balaban and I. Ronin (Hebrew U, IL) for advice, and Yoav Smith, Norman Grover, and Suaad Abd-Elhadi (Hebrew U, IL) for helping with statistical analysis. We are grateful to members of the Ben-Yehuda laboratory for valuable comments. S.B.-Y. designed the experiments, analyzed the data, and wrote the paper. R.H. designed and performed the experiments, analyzed the data, and wrote the paper.
Funding Information:
This study was supported by the European Research Council Advanced Grant (339984) and by the Israel Science Foundation grant (774/16) awarded to S.B.-Y. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Publisher Copyright:
© 2019 Hashuel and Ben-Yehuda.