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In Vesiculo Synthesis of Peptide Membrane Precursors for Autonomous Vesicle Growth
Published on: June 28, 2019
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Autolysis-mediated membrane vesicle formation in Bacillus subtilis
Kimihiro Abe1, Masanori Toyofuku1,2, Nobuhiko Nomura1,2
1Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan.
Environmental Microbiology
|April 5, 2021
Summary
Bacillus subtilis releases membrane vesicles (MVs) during stress through autolysis, a novel pathway independent of prophage genes. These MVs protect cells from surfactant-induced lysis, enhancing viability.
Area of Science:
- Microbiology
- Cell Biology
- Bacterial Physiology
Background:
- Bacillus subtilis is known to release membrane vesicles (MVs) during the SOS response, linked to prophage-induced cell lysis.
- The role of MVs and the mechanisms of their release under various stress conditions require further elucidation.
Purpose of the Study:
- To investigate the role of autolysis and prophage-encoded enzymes in Bacillus subtilis MV production under diverse stress conditions.
- To determine the protective function of MVs against cell lysis induced by external stressors.
Main Methods:
- Induction of stress conditions including sucrose fatty acid ester (SFE) treatment, cold shock, starvation, and oxygen deficiency.
- Generation of B. subtilis deletion mutants for autolysin genes (LytC, LytD, LytE, LytF) and prophage-related genes (xhlAB, xlyA).
- Analysis of autolysis, MV production, and cell viability in wild-type and mutant strains.
- Assessment of the protective effect of exogenous MVs against SFE-induced cell lysis.
Main Results:
- Bacillus subtilis releases MVs under various stress conditions, including SFE treatment, cold shock, starvation, and oxygen deficiency.
- Deletion of autolysin genes abolished stress-induced autolysis and subsequent MV production, identifying autolysis as crucial for MV biogenesis.
- Prophage-encoded genes xhlAB and xlyA were not involved in autolysis-triggered MV production.
- Exogenous MVs effectively neutralized cell lysis induced by surfactant treatment, protecting bacterial cells.
Conclusions:
- Autolysis is a novel and prophage-independent pathway for MV production in Bacillus subtilis under stress.
- Bacillus subtilis MVs play a protective role, acting as decoys to shield cells from membrane damage by surfactants.
- The study highlights a positive effect of MVs on cell viability and underscores the biological significance of autolysis.
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