Salinity Tolerance of Alishewanella Species Isolated from Seawall Muddy Water

Begin with a culture of Alishewanella, a Gram-negative, salt-tolerant bacterium.

Next, streak the culture onto agar plates containing increasing concentrations of sodium chloride to simulate varying levels of saline stress.

Overlay each plate with a layer of unsolidified medium to prevent oxygen diffusion and maintain the culture in an oxygen-limited environment.

Seal and incubate the plates at an optimum temperature to support bacterial growth.

During incubation, the bacterium exhibits varying growth rates across the plates with different sodium chloride concentrations.

The bacterium develops saline tolerance through osmoregulatory mechanisms, such as the accumulation of compatible solutes to balance intracellular osmotic pressure, active ion transport to preserve cellular function, and the expression of salt-stable enzymes and chaperone proteins.

Robust growth at low to moderate salinity and reduced but detectable growth under high salinity conditions indicates strong saline tolerance.