Blue-Green Bacteria

Day 2

Welcome to Class

Please take out your notebook.Be ready to write. 

 

Blue green algae have cells walls similar to eubacteria

Blue Green Algae?

Blue Green Pigment (Phycocyanin and Chlorophyll)

No Membrane bound Organelles (No Nucleus)

Single cell but form coloniesPerform Photosynthesis

• Question: Algae or Bacteria?

What is blue-green bacteria?

• A phylum of bacteria• Gets energy through photosynthesis• Found everywhere (hotsprings, artic,

antartica)• Can live as one cell or in colonies,

filaments, sheets or hollow balls

Nostoc Colony “Star Jelly”

What are some cell types of blue green bacteria?

• Normal cells• Cells with resistant spores (akinetes)• Thick walled cells for fixing nitrogen

(heteocysts)

What are some parts of blue-green bacteria

• Thick, gelatin cell wall• No flagella• How do they reproduce? Hormogonia

are filaments that glide away from the main mass, bud, and reproduce.

Global Importance of Bacteria

Diverse Bacteria• Nitrogen Fixers: Heterocysts aid in nitrogen

fixation. To "fix" nitrogen gas, means to change nitrogen which cannot be absorbed by plants, into ammonia (NH3), nitrites(NO2) or nitrates (NO3), which can be absorbed by plants and converted to protein and nucleic acids)

• Photosynthesis

Anabaena

• look like chains of tiny grapes• can fix its own nitrogen• produces a chemical that is

toxic to many species of animals.

• similar to Nostoc, except large balls are not normally formed. Cells more elongate, less rounded.

Spirogyra

• From Greek speira, "coil" + gyros, "twisted"

• Most diverse of the conjugating green algae,

• Almost half of these can be found in North America.

• Shape: The genus usually exists as loose, floating mats,

• Forms extensive but harmless springtime blooms in freshwater ponds.

• http://video.conncoll.edu/f/pasiv/lucid/Spirogyra-900.html

Oscillatoria

• Very common. • Shape-

Well defined unbranched filaments (simple or interwoven into dense mat)Reproduction - fragmentation at separation discs;

Nostoc

• Occurs in soil and in fresh-water Form:

• Twisted trichomes with individual sheath, often aggregated into large gelatinous balls.

• Heterocysts present, fragment here. Akinetes formed when colony matures.

• Nostoc Often associated with fungi in lichens, filamentous, can form colonies, akinetes midway between heterocysts.