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• cyanobacteria
  cyanobacteria

  plural noun

  a widely distributed group of photosynthetic bacteria, occurring singly or in colonies in terrestrial and aquatic habitats: often mistakenly referred to as algae, especially when called by their most common misnomer, blue-green algae .
• Cyanobacteria
  Cyanobacteria

  noun

  the phylum, or subkingdom, that comprises the cyanobacteria.

cyanobacteria

¹ American  

[sahy-uh-noh-bak-teer-ee-uh, sahy-an-oh-] / ˌsaɪ ə noʊ bækˈtɪər i ə, saɪˌæn oʊ- /

plural noun

1. Microbiology. a widely distributed group of photosynthetic bacteria, occurring singly or in colonies in terrestrial and aquatic habitats: often mistakenly referred to as algae, especially when called by their most common misnomer, blue-green algae .

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Cyanobacteria ² American  

[sahy-uh-noh-bak-teer-ee-uh, sahy-an-oh-] / ˌsaɪ ə noʊ bækˈtɪər i ə, saɪˌæn oʊ- /

noun

Microbiology.

1. the phylum, or subkingdom, that comprises the cyanobacteria.

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cyanobacteria British  

/ ˌsaɪənəʊbækˈtɪərɪə /

plural noun

1. Former name: blue-green algae.  a group of photosynthetic bacteria (phylum Cyanobacteria ) containing a blue photosynthetic pigment

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Etymology

Origin of cyanobacteria¹

First recorded in 1975–80; cyano- ¹ + bacteria

Origin of Cyanobacteria²

See cyanobacteria ( def. )

Example Sentences

The largest forms resemble green or red algae, while the smaller fossils may represent algae, cyanobacteria, or sulfur-oxidizing bacteria.

From Science Daily • May 12, 2026

Multicellular cyanobacteria evolved gradually from single-celled ancestors, gaining complexity over time.

From Science Daily • Apr. 20, 2026

The region also preserves some of the earliest evidence of life, including stromatolites and microbialite formations created by single-celled organisms such as cyanobacteria.

From Science Daily • Mar. 21, 2026

The beauty of the sky contrasts sharply with the water, sometimes blue, but often a murky green from cyanobacteria or stained black.

From BBC • Jan. 29, 2026

The research team isolated eight strains of heat-tolerant cyanobacteria from the Bo Khlueng hot spring in Ratchaburi Province, Thailand.

From Science Daily • Jan. 13, 2026