Definition of Cyanobacteria in US English:


plural noun

  • 1A division of microorganisms that are related to the bacteria but are capable of photosynthesis. They are prokaryotic and represent the earliest known form of life on the earth.

    Class Cyanophyceae, kingdom Eubacteria

    • ‘The significant buildup probably began about two billion years ago, with the appearance of Cyanobacteria.’
    • ‘That is, all Cyanobacteria and algal chloroplasts are, together, all of the descendants of some unique common ancestral cyanobacterium.’
    • ‘Only Aquificales and Cyanobacteria do not present evidence of such a structuring, possibly because of a sampling effect, since only a few bacteria of these phyla have been presently sequenced.’
    • ‘They occur only in Cyanobacteria and Rhodophyta.’
    • ‘Click on the buttons below to find out more about the Cyanobacteria.’
    1. 1.1as plural noun cyanobacteria Microorganisms of the Cyanobacteria division.
      Also called blue-green algae
      • ‘Most of the lichen is composed of fungal filaments, but living among the filaments are algal cells, usually from a green alga or a cyanobacterium.’
      • ‘In Florida scrub, soil crusts include algae, cyanobacteria, and diatoms.’
      • ‘We conclude that there is no evidence available to support assignment of Halysis either to chlorophyte algae or to cyanobacteria.’
      • ‘Unlike any other flagellate algae, they contain phycobilins as accessory photosynthetic pigments, as do red algae and cyanobacteria.’
      • ‘They have discovered cellulose biosynthesis in nine species of cyanobacteria, or blue-green algae.’


Modern Latin (plural), from Greek kuaneos ‘dark blue’ + plural of bacterium.