Cyanobacteria

Cyanobacteria
Microbial group
Group characteristics
images
description and significance
genomic information if known
cell structure and metabolism
ecology
phylogeny
Individual species or genera and their characteristics (one per group member)
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habitat
growth conditions (if known)
References
Cyanobacteria
Cyanobacteria
Description and Significance
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First oxygen-evolving phototrophic organism
Oxygenic Phototrophs
Can be unicellular or filamentous
Many are Nitrogen fixers using heterocytes
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Cell Structure
Genomic Information
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Unicellular forms vary from 35-71% GC
content.
The wide range suggests that this group has
many members with little relationship to
each other.
Heterocytes are empty looking round cells that are
distributed along a filament.
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Contains Plasma membrane and Cell wall
Does not include a nuclear envelope or
membrane bound organelles
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Metabolism
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Carries out Photosynthesis
Autotrophic
can convert inert atmospheric nitrogen into
an organic form, such as nitrate or ammonia
Ecology and Phylogeny
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Merismopedia
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Pictures of Merismopedia
Unicellular group that can form colonies
Reproduce by binary fission
Live in freshwater of marine habitat
Can be either floating in water of living on a
substrate
When growing in colonies it is enclosed in a
mucilaginous sheath
Colonies grow in flat square or rectangular sheets
Oscillatoria
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Tolerant to environmental extremes
Widely distributed in nature: terrestrial,
freshwater and marine
Known fossils date back 3.5 billion years
Chloroplast is actually a cyanobacterium
moving within that plant cell
This genus us named for the gliding, rotating
or oscillating motion of the filament around
its axis.
Hot springs, temperate, tropical, polar lakes
and moist terrestrial environments
Reproduces by fragmentation
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Fischerella
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wet rocks, acidic soils. Aquatic species are found attached to
submerged wood or among other algae. Several species grow
only on mosses and tree barks in tropical forests.
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thermophile – thrives in temperatures greater than 45° C.
Filaments breaking apart
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Anabaena
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Habitat
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Pictures of Anabaena
Anabaena lives in the leaves of ferns
This is where it fixes nitrogen
It is filamentous, however the filaments are very short
Growth Conditions
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Anabaena can be either heterotrophic or autotrophic
It is capable of heterotrophic growth in complete darkness
the doubling time for anabaena is approximately 14 hours
References
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www.uni-frankfurt.de/~schauder/cyanos/cyanos.html
http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobact
eria/Cyanobacteria.htm
Brock Biology of Microorganisms (textbook)
www.pubmed.gov
http://silicasecchidisk.conncoll.edu/LucidKeys/Carolina_Key/ht
ml/Fischerella_Ecology.html
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