- singular of cyanobacteria.
cyanobacterium
Americannoun
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cyanobacteria
plural
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cyanobacteria
plural
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Any of a phylum of photosynthetic bacteria that live in water or damp soil and were once thought to be plants. Cyanobacteria have chlorophyll as well as carotenoid and phycobilin pigments, and they conduct photosynthesis in membranes known as thylakoids (which are also found in plant chloroplasts). Cyanobacteria may exist as individual cells or as filaments, and some species live in colonies. Many species secrete a mucilaginous substance that binds the cells or filaments together in colored (often bluish-green) masses. Cyanobacteria exist today in some 7,500 species, many of which are symbiotes, and have lived on Earth for 2.7 billion years. Since all species produce oxygen as a byproduct of metabolism, it is thought that much of Earth's atmospheric oxygen can be attributed to cyanobacteria. Many species can also fix nitrogen and so play an important role in the nitrogen cycle.
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Also called blue-green alga
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Chloroplasts developed in the course of evolution when the ancestors of today's plant cells absorbed a photosynthetic cyanobacterium.
From Science Daily ● Mar. 1, 2024
The most feared—and studied—cause of these freshwater “algal” blooms is a genus of cyanobacterium called Microcystis.
From Science Magazine ● Jul. 5, 2022
The two are forever on the trail of these composite symbiotic organisms, which they describe in the book as “an intensive cooperation between a fungus and an alga or a cyanobacterium, and sometimes all three.”
From Seattle Times ● Nov. 22, 2021
Some 2 billion years ago, a single-celled organism in Earth’s primeval ocean engulfed a mitochondrion and a cyanobacterium — and, now able to generate energy and photosynthesize, shunted off to change the world.
From Nature ● Apr. 2, 2019
Genetic and morphological studies suggest that plastids evolved from the endosymbiosis of an ancestral cell that engulfed a photosynthetic cyanobacterium.
From Textbooks ● Apr. 25, 2013
Multicellular cyanobacteria evolved gradually from single-celled ancestors, gaining complexity over time.
From Science Daily ● Apr. 20, 2026
Even today, cyanobacteria remain essential to life on Earth.
From Science Daily ● Apr. 20, 2026
Scientists estimate that cyanobacteria emerged around 2.9 billion years ago.
From Science Daily ● Feb. 18, 2026
Previous studies helped establish that cyanobacteria began producing oxygen around 2.9 billion years ago, while oxygen did not permanently accumulate in the atmosphere until roughly 2.33 billion years ago during the Great Oxidation Event.
From Science Daily ● Feb. 18, 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
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
