Survival of selected bacteria and fungi in hypertonic (7.2%) saline

Salt stress—which can be triggered by high salt concentrations in a plant’s environment—can significantly affect plant growth and crop production by influencing photosynthesis and the absorption of water and nutrients.

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 the cell,...

Endospores are specialized, dormant cells primarily formed by Gram-positive bacteria, including Bacillus and Clostridium, enabling survival under extreme environmental conditions. Due to their unique composition and formation process, these structures are highly resistant to physical and chemical insults, such as extreme heat, ultraviolet and ionizing radiation, desiccation, and toxic chemicals. Rare instances of endospore-like structures have also been observed in some Gram-negative bacteria,...

Microbial growth media are essential tools in microbiology, providing the nutrients and conditions necessary to cultivate and study microorganisms. These media are categorized by their composition, consistency, and functional roles, enabling researchers to investigate microbial physiology, behavior, and interactions.Types and Consistencies of Growth MediaGrowth media can be solid, liquid, or semisolid. Solid media, often agar-based, allow visible colony growth for isolation and enumeration.

Microorganisms are classified as acidophiles, neutrophiles, or alkaliphiles based on their pH growth preferences, reflecting their adaptations to specific environments. Maintaining a stable intracellular pH is critical for macromolecular stability and enzymatic activity, which can be challenged by external pH variations.Neutrophiles, such as Escherichia coli, grow optimally between pH 5.5 and 8.0. These microorganisms inhabit neutral or slightly acidic environments and employ mechanisms like...

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...