Nonlethal deleterious mutation-induced stress accelerates bacterial aging.

Area of Science:

• Microbiology
• Genetics
• Cell Biology

Background:

• Microbial adaptation relies on random mutagenesis, often causing gene loss.
• Deleterious mutations trigger cellular stress responses (allostasis) for survival.

Purpose of the Study:

• To investigate the effects of 65 gene deletions on E. coli growth in varied environments.
• To analyze transcriptome changes and single-cell phenotypes in specific mutants, including ATP synthase subunit deletions.

Main Methods:

• Systematic screening of 65 single-gene deletion mutants in E. coli across three environments.
• Transcriptome profiling of select mutants, focusing on adenosine triphosphate (ATP) synthase subunit deletions.
• Single-cell analysis of growth, proliferation, and senescence in ATP synthase alpha-subunit deleted (ΔatpA) cells.

Main Results:

• Mutants showed environment- and gene-specific transcriptome reorganization.
• ΔatpA cells exhibited higher metabolic rates but slower growth than wild-type.
• Single ΔatpA cells displayed early senescence and a post-replicative state, despite normal proliferation.

Conclusions:

• Bacterial adaptation involves a trade-off between population resilience and individual cell