Definition

Noun 1. Phototrophic bacteria: A group of bacteria (specifically green and purple bacteria) that obtain energy for growth from sunlight through a process called photosynthesis. Unlike plants, their carbon source can be either carbon dioxide or organic carbon compounds.

Usage Notes

• This is a scientific term used primarily in microbiology and biology.
• It refers to a specific functional group of bacteria defined by their metabolic process (using light for energy) rather than a single taxonomic family.
• The term is often used in contrast to "chemotrophic bacteria," which derive energy from chemical reactions.

Examples

• Scientific Context:
  • The study focused on the unique pigments found in phototrophic bacteria.
  • In this anoxic zone of the lake, phototrophic bacteria form colorful microbial mats.
  • These phototrophic bacteria can use hydrogen sulfide as an electron donor during photosynthesis.

Advanced Usage

• The term is frequently modified to specify the type:
  • Anoxygenic phototrophic bacteria: Do not produce oxygen as a byproduct of their photosynthesis.
  • Purple sulfur bacteria / Green sulfur bacteria: Specific subgroups named for their color and metabolic traits.

Variants and Related Words

• Phototroph (n): Any organism that uses light as its primary energy source. "Phototrophic bacteria" are a type of phototroph.
• Phototrophy (n): The condition or process of obtaining energy from light.
• Photosynthetic bacteria: A broader, sometimes synonymous term, though it can include cyanobacteria, which produce oxygen.

Synonyms

• Photosynthetic bacteria (in specific contexts, though this can be a broader category)
• Phototrophs (a broader category including plants, algae, and these bacteria)

Related Scientific Phrases

• Anoxygenic photosynthesis: The type of photosynthesis performed by most phototrophic bacteria, which does not result in oxygen gas.
• Bacteriochlorophyll: The light-harvesting pigment unique to these bacteria, different from the chlorophyll found in plants.

Noun

1. green and purple bacteria; energy for growth is derived from sunlight; carbon is derived from carbon dioxide or organic carbon