Halobacteria

Definition

Halobacteria are a class of extremophilic archaea that thrive in highly saline environments. They are known for their unique adaptations to high salt concentrations, such as specialized cell membrane proteins and enzymes.

5 Must Know Facts For Your Next Test

1. Halobacteria can survive in salt concentrations that would be lethal to most other microorganisms, often exceeding 20% NaCl.
2. They use light-absorbing molecules like bacteriorhodopsin to generate energy through a process similar to photosynthesis.
3. The cell walls of Halobacteria contain high levels of glycoproteins rich in acidic amino acids which help stabilize them in salty conditions.
4. Halobacteria are obligate halophiles, meaning they require high salt concentrations not just to thrive but to survive.
5. They reproduce through binary fission, similar to other prokaryotes, but exhibit unique genetic mechanisms like horizontal gene transfer.

Review Questions

• What environmental conditions do Halobacteria require for survival?
• How do Halobacteria generate energy in high saline environments?
• Why are glycoproteins important for the stability of Halobacteria cell walls?

Related terms

Bacteriorhodopsin: A protein used by Halobacteria to absorb light and generate ATP.

Obligate Halophile: An organism that must have high salt concentrations for growth and survival.

Horizontal Gene Transfer: The movement of genetic material between organisms other than by transmission from parent to offspring.