Blue-Green Bacteria

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Blue-Green Bacteria

• Anabaena
• Gleocapsa
• Nostoc
• Oscillatoria

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What are Blue-Green Bacteria?

• aquatic
• unicellular, but grow in colonies large enough to
  see

• photosynthetic
• oldest known fossils are 3.5 million years old

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Where does the blue-green color come from?

• get name from a bluish pigment phycocyanin
• also have chlorophyll a
• reddish or pink strains have phycoerythrin

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Importance of Blue-Green Bacteria

• nitrogen fixation
• first free oxygen
• origin of plants
• photosynthesis (primary producer in many
  ecosystems)

• symbiotic relationships with legumes
• endosymbiosis

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What are we going to be doing?
Oscillatoria
Anabaena
Gleocapsa
Nostoc
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Anabaena

• single, straight chain of spherical cells (looks
  like a necklace)
• heterocyst-forming
• nitrogen fixation
• anaerobic environment

Azolla
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Gleocapsa

• group of oval-shaped cells arranged within a
  mucus capsule (gelatinous sheath)

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Oscillatoria

• filaments made up of disc-shaped single cells
  cells at ends of filament tapered or rounded

• named for rotating motion around axis of filament
• inhabits diverse environments
• form dense, slimy mats of mud, plants, stones, or
  sand
• can perform aoxygenic photosynthesis and release
  sulfur rather than oxygen

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Nostoc

• numerous coiled filaments of spherical cells
  which may comprise a visible globular
  (ball-shaped) mass looking like a squished grape
• has a gelatinous sheath

• heterocyst-forming
• nitrogen fixation
• anaerobic environment
• abundant in rice paddies