cyanophyta

Cyanophyta
(bluegreen bacteria; Chloroxybacteria)

Introduction to Cyanophyta
I.
II.
III.
IV.
V.
VI.

Some Superlatives:

Intro to Cyanobacteria
Some Superlatives
General Cellular Features
Diversity in Reproduction
Diversity in Morphology
Prochlorophytes

• 1st group of algae (3-4 bya)
• 1st O2 producers
• survive in diverse environments in ice, on soil, on bark, on rocks halophilic, thermophilic marine, freshwater symbiotic • Nitrogen fixation

General Cellular Structure

Cyanophyta (top 10!)
• unicellular, colonies, filaments
• no flagella
• no organelles, E.R., vacuoles
• Ps pigments in un-stacked thylakoids
• Chl a (b and c sometimes)
• accessory pigments give blue-green color
• storage product is cyanophycean starch
• DNA circular (no nucleus)
• cell wall is peptidoglycan
• no sex
• fw, marine, terrestrial, symbiotic

w/ phycobilisomes ribosomes granules gas vesicle
Sheath
lipopolysaccharides

Circular DNA
(plasmids common)

Cell structures cont.

Gas vesicles cell rises

• small cells (bacteria size 1-10 µm)
• no complex organelles
c.w.
• typical cell
(peptidoglycan)
thylakoids

phtosynthetic pigments

high light
• storage products ↑
• ion uptake ↑
• turgor ↑

chlorophyll a - all spp. Have chl b in Gluacophytes phycobiliproteins - accessory pigments

low light
• respiration reduces storage products
• gas vesicles expand • attached to thylakoids

cell sinks

• produce phycobilisomes (granular collection of phycobiliproteins)

1

Cell structures cont.

phtosynthetic pigments cont.

granules: several types

4 types of
Accessory Pigments

• cyanophycean starch - major storage product Chl a
• cyanophycin - protein storage

green

1. Phycoerythrin
4. Allophycocyanin

• carboxysomes - store photosynthetic enzymes 2. Phycoerythrocyanin red 3. Phycocyanin

Diversity in Reproduction cont.

Diversity in Reproduction

Binary fission

•