Spirillum

Definition

Spirillum is a genus of bacteria characterized by its spiral or helical shape. These prokaryotic cells are typically found in aquatic environments and are known for their motility, which is often facilitated by flagella. Spirilla are distinct from other bacterial shapes, such as cocci (spherical) and bacilli (rod-shaped), and they play a role in various ecological processes.

5 Must Know Facts For Your Next Test

1. Spirillum species are typically aerobic, requiring oxygen for growth, and are often found in fresh water environments.
2. They have a distinctive corkscrew motion that helps them navigate through liquid environments, which is an adaptation for survival.
3. The cell wall of spirilla contains peptidoglycan, which provides structural support and determines the rigidity of the cell.
4. Some species of spirillum can engage in nitrogen fixation, contributing to nutrient cycling in their ecosystems.
5. Spirilla can be used as bioindicators in environmental monitoring because their presence often reflects the health of aquatic ecosystems.

Review Questions

• How does the unique shape of spirillum bacteria influence their movement and ecological role?
  • The spiral shape of spirillum bacteria enables them to move in a corkscrew manner, which is advantageous for navigating through viscous aquatic environments. This motility allows them to efficiently seek nutrients and evade predators. Additionally, their movement style may help them colonize specific niches within freshwater ecosystems, playing important roles in nutrient cycling and interactions with other microorganisms.
• Compare and contrast spirillum with other bacterial shapes regarding their structure and functions.
  • Spirillum differs from cocci and bacilli in its helical shape, which influences its motility and habitat preferences. Cocci are spherical and often form clusters or chains, while bacilli are rod-shaped and can also be found in chains. The structural differences affect their functions; for example, spirillum's corkscrew movement allows for better navigation in liquid environments compared to the more straightforward movements of cocci and bacilli. These structural variations also lead to different ecological roles within their respective environments.
• Evaluate the ecological significance of spirillum species in freshwater ecosystems and their role as bioindicators.
  • Spirillum species play a vital role in freshwater ecosystems by participating in nutrient cycling processes such as nitrogen fixation. Their ability to convert atmospheric nitrogen into a form usable by plants contributes to ecosystem productivity. As bioindicators, the presence or absence of spirilla can provide insights into water quality and ecosystem health. Monitoring these bacteria helps researchers understand changes in environmental conditions, pollution levels, and the overall stability of aquatic habitats.

Related terms

Prokaryotic Cells:

Cells that lack a nucleus and membrane-bound organelles, with their genetic material freely floating in the cytoplasm.

Flagella: Long, whip-like structures that protrude from the cell body of some bacteria, providing motility.

Bacterial Morphology: The study of the shape, size, and arrangement of bacteria, which includes categories like cocci, bacilli, and spirilla.