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Microbial group

Group characteristicsimagesdescription and significancegenomic information if knowncell structure and metabolismecologyphylogeny

Individual species or genera and their characteristics (one per group member)imageshabitatgrowth conditions (if known)

References

Cyanobacteria

Cyanobacteria CyanobacteriaDescription and Significance

First oxygen-evolving phototrophic organism Oxygenic Phototrophs Can be unicellular or filamentous Many are Nitrogen fixers using heterocytes

– Heterocytes are empty looking round cells that aredistributed along a filament.

Genomic Information

Unicellular forms vary from 35-71% GCcontent.

The wide range suggests that this group hasmany members with little relationship toeach other.

Cell Structure Contains Plasma membrane and Cell wall Does not include a nuclear envelope or

membrane bound organelles

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Metabolism Carries out Photosynthesis Autotrophic can convert inert atmospheric nitrogen into

an organic form, such as nitrate or ammonia

Ecology and Phylogeny

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

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

Pictures of Merismopedia

Oscillatoria

This genus us named for the gliding, rotatingor oscillating motion of the filament aroundits axis.

Hot springs, temperate, tropical, polar lakesand moist terrestrial environments

Reproduces by fragmentation– Filaments breaking apart

Fischerella

wet rocks, acidic soils. Aquatic species are found attached tosubmerged wood or among other algae. Several species growonly on mosses and tree barks in tropical forests.

thermophile – thrives in temperatures greater than 45° C.

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Anabaena Habitat

Anabaena lives in the leaves of ferns This is where it fixes nitrogen It is filamentous, however the filaments are very short

Growth Conditions 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

Pictures of Anabaena

References 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