🦠microbiology review

Planktonic

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Planktonic refers to microorganisms that are free-floating in a liquid environment, as opposed to being attached to a surface. These microbes can include bacteria, algae, protozoa, and other single-celled organisms.

5 Must Know Facts For Your Next Test

  1. Planktonic microorganisms are typically found in aquatic environments such as oceans, lakes, and rivers.
  2. Many planktonic bacteria can switch between planktonic and biofilm modes of growth depending on environmental conditions.
  3. Planktonic cells are often more susceptible to antibiotics compared to their biofilm counterparts.
  4. The study of planktonic microbes is crucial for understanding microbial ecology and the dynamics of microbial communities in natural environments.
  5. Planktonic growth is usually measured using techniques such as turbidity measurements and colony-forming unit (CFU) counts.

Review Questions