Related Experiment Video
Updated: Oct 21, 2025
12:08
Multi-scale Analysis of Bacterial Growth Under Stress Treatments
Published on: November 28, 2019
9.6K
Hyperosmotic Shock Transiently Accelerates Constriction Rate in Escherichia coli
Jiawei Sun1, Handuo Shi1,2, Kerwyn Casey Huang1,2,3
1Department of Bioengineering, Stanford University, Stanford, CA, United States.
Frontiers in Microbiology
|September 7, 2021
Summary
Bacterial cells adapt to osmotic shocks by altering cell division and envelope synthesis. This study introduces a new method to measure cell envelope stiffness and reveals how bacteria maintain integrity under osmotic stress.
Area of Science:
- Microbiology
- Cell Biology
- Biophysics
Background:
- Bacteria face environmental osmotic challenges, impacting cell envelope integrity and growth.
- Understanding bacterial responses to osmotic shock is crucial for cell envelope regulation.
Purpose of the Study:
- To develop a novel method for measuring bacterial cell envelope stiffness.
- To investigate bacterial physiological responses to hyperosmotic shock, focusing on cell envelope integrity and synthesis.
Main Methods:
- Developed an agarose pad-based protocol to measure cell envelope stiffness via population-averaged cell length changes.
- Utilized microfluidic devices for single-cell dynamics comparison.
- Quantified FtsZ concentration and Z-ring intensity post-shock.
Main Results:
- The agarose pad method accurately quantifies cell envelope stiffness after osmotic shock.
- Hyperosmotic shock transiently increases bacterial cell division rate and FtsZ levels.
- Cell division inhibition reconciles measurements between agarose pad and microfluidic methods.
Conclusions:
- The developed agarose pad protocol is effective for assessing cell envelope stiffness.
- Mechanical perturbations significantly influence bacterial physiology, including cell division and envelope regulation.
- Bacteria actively regulate envelope synthesis and integrity in response to osmotic stress.
Related Concept Videos
01:23Stringent Response in E. coli
93
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
93
02:40Osmosis and Osmotic Pressure of Solutions
43.0K
A number of natural and synthetic materials exhibit selective permeation, meaning that only molecules or ions of a certain size, shape, polarity, charge, and so forth, are capable of passing through (permeating) the material. Biological cell membranes provide elegant examples of selective permeation in nature, while dialysis tubing used to remove metabolic wastes from blood is a more simplistic technological example. Regardless of how they may be fabricated, these materials are generally...
43.0K
01:16Tonicity in Animals
4.8K
Tonicity describes the amount of solute in a solution. The measure of the tonicity of a solution, or the total amount of solutes dissolved in a specific amount of solution, is called its osmolarity. Three terms—hypotonic, isotonic, and hypertonic—are used to relate the osmolarity of a cell to the osmolarity of the extracellular fluid that contains the cells. In a hypotonic solution, such as tap water, the extracellular fluid has a lower concentration of solutes than the fluid inside...
4.8K
01:28Factors Influencing Microbial Growth: Osmolarity
315
Osmolarity is the measure of solute concentration in a solution. It plays a critical role in determining water availability for organisms. Water moves across semipermeable membranes through osmosis, flowing from regions of lower solute concentration (more dilute) to regions of higher solute concentration (more concentrated).In high-solute environments, microbial cells lose water, leading to dehydration and inhibited growth. The extent to which water is available to microbes in such environments...
315
01:30Other Stress Responses in Bacteria
123
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
123
00:53Tonicity in Plants
56.8K
Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity delimits the magnitude and direction of osmosis and results in three possible scenarios that alter the volume of a cell: hypertonicity, hypotonicity, and isotonicity. Due to differences in structure and physiology, tonicity of plant cells is different from that of animal cells in some scenarios.
56.8K