🦠microbiology review

Purple nonsulfur bacteria

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

Definition

Purple nonsulfur bacteria are a group of phototrophic bacteria capable of photosynthesis without producing oxygen. They can grow in the presence or absence of light and use organic compounds as electron donors.

5 Must Know Facts For Your Next Test

  1. They are classified under the family Rhodospirillaceae.
  2. They perform anoxygenic photosynthesis, meaning they do not produce oxygen.
  3. These bacteria can switch between photoheterotrophic and chemoheterotrophic growth modes.
  4. They contain bacteriochlorophylls and carotenoids, which give them their distinctive color.
  5. They are typically found in aquatic environments like ponds, lakes, and hot springs.

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