Organisms

1. Magallanes Campus
Magallanes, Sorsogon

4. Evolution
• Old 3.5 billion years
• Dominated as biogenic reefs
• During Proterozoic – Age of
Bacteria (2.5 bya – 750 mya) they
were wide spread
• Then multicellularity took over
• Cyanobacteria were first
algae!

5. Cyanobacteria terminology
- Division Cyanophyta
- Cyanobacteria ‘formerly known
as’ BlueGreen Algae
- Cyano = blue
- Bacteria – acknowledges that
they are more closely related to
prokaryotic bacteria than
eukaryotic algae

6. Cyanobacteria
-Microscopic organisms
- Found in marine sediments and
pelagic zone, freshwater lakes,
soils,
- Live in extreme environments –
chemically and temperature.

7. Importance
1) First organisms to have 2
photosystems and to produce
organic material and give off O2 as a
bi-product.
Very important to the evolution of
the earths’ oxidizing atmosphere .
!!!

8. Importance
2) Many – fix or convert atmospheric
nitrogen into usable forms through
Nitrogen Fixation when other forms are
unavailable.
IMPORTANT because atmospheric N2 is
unavailable to most living organisms
because breaking the triple bond is
difficult N N

9. Cyanobacteria
Characteristics
- Pigments – chl a,
phycobiliproteins
- phycoerythrin
- phycocyanin * BlueGreen Color
- allophycocyanin
- Storage – glycogen
- Cell Walls – amino acids, sugars

10. Habit – success due to ability
tolerate a wide range of conditions
• Marine – littoral and pelagic
• Fresh Water
• Hot Springs
• Terrestrial – soil flora

11. Advantage for Cyanobacteria
• Can live in fluctuating
environments of aerobic and
anaerobic with light present.

12. Cyanotoxins in Cyanobacteria
• Neurotoxins – block neuron
transmission in muscles (Anabaena,
Oscillatoria)
• Hepatotoxins – inhibit protein
phosphatase, cause liver bleeding.
Found in drinking water. (Anabaena,
Oscillatoria, Nostoc)
Eg. swimmers itch - Lygnbia

13. Movement
• No flagellae or structures to enhance
movement
A) Excrete mucilage – jet propulsion, gliding
B) Helix – fibers send waves of contraction
Spirulina

14. Spirulina
• filamentous
• common in lakes with high pH
• major food for flamingo populations
• commercial food source

15. Anabaena with a heterocyst
- common bloom forming species with nutrient loads

16. Lyngbia martensiana
Releases chemicals causing dermatitis

17. Asexual Reproduction
- Hormogonia formation -
- Endospore / Akinete formation -
- Fragmentation –
- Exospore

18. Asexual Reproduction
Hormogonia – short piece of trichome
found in filaments. It detaches from
parent filament and glides away
Hormogonia

19. Oscillatoria with hormogonia
- short pieces of a trichome that become detached
from the parent filament and glide away to form
new filament.

20. Oscillatoria (filamentous) with hormogonia

21. Asexual Reproduction
Akinete – thick walled resting spore
A - akineteH

22. Akinete

23. Asexual Reproduction
Akinete – thick walled resting spore
Function – resistant to unfavorable
environmental conditions.
Appear as larger cells in the chain and
different than heterocyst. Generally lose
buoyancy
A - akineteH

24. Asexual Reproduction
Fragmentation - fragmentation

25. Oldest Fossils
• 3.5by old carbonaceous microfossils S.Africa
• 3.4by old filaments and microbial fossils –
W. Australia
• 3.4 by old stromatolites – S.Africa, Australia

26. Cyanobacteria as Food
Flamingoes feeding on Spirulina
in alkaline Lake Nakuru, Kenya
* Spirulina contains 70% its dry weight as protein
* Spirulina grows well in saline and alkaline ponds in arid
environments
* Native peoples near Lake Chad (Africa) and Lake Texcoco
(Mexico) have traditionally used Spirulina as food
* Spirulina is grown commercially in California, Israel, Japan,
Thailand & Mexico

32. Characteristics
• Eukaryotic
• Pigments: chlorophyll a & b, carotenoids
• Food storage: paramylon (polymer of
glucose)
• Cell wall: typically none; have pellicles, strips
of protein within cell membrane which impart
semi-rigidity
• Typically biflagellate
• Typically indicators of enrichment
• Eyespot present

35. Pellicle

36. Eudorina Gonium

37. Euglena

39. Volvox, fluorescence
microscopy

41. Dinoflagellates
• Pyrrhophyta is the phylum
name of the dinoflagellates.

42. About Dinoflagellates
• 90% of all dinoflagellates are marine
plankton.
Although many of them are
microscopic, the largest, Noctiluca, may
be as large as 2 mm in diameter!

43. Not related to Dinosaurs
• The prefix Dino
means whirling
flagella. The
Dinoflagellates are
said to of out dated
the Dinosaur

44. What they look like
• As you can see in the
picture the
dinoflagellates are a
very ugly animal but
without them you
and I wouldn’t be
able to breathe
because they make
most of the worlds
oxygen

45. Anatomy
• This is the anatomy of a Dinoflagellate.

46. How they get around
• Dinoflagellates swim
by means of two
flagella, movable
protein strands
which propel the cell
through the water.
So basically the
move like semen.

47. Good but Bad
• The Dinoflagellates
are good because
they give us oxygen
but they also are bad
because they produce
the Red Tide which
destroys fishing
based economies
because the fish eat
the Dinoflagellates
with red tide and die.

48. Reproduction
• The most form of
reproduction is
asexual, where
daughter cells form
by simple mitosis
and division of the
cell. The daughter
cells will be
genetically identical
to that of the
original cell.

50. Cryptomonads, e.g Syneura
spp., range from 5 - 30 µm
in diameter, Some species
form gelatinous colonies.
They are common in water
with a high nitrogen
content, e.g. estuaries and
semi-enclosed seas.

53. Mostly freshwater eukaryotic
algae having the chlorophyll
masked by brown or yellow
pigment; yellow-green and
golden-brown algae and
diatoms:

54. • The golden algae or chrysophytes
are a large group of algae, found mostly
in freshwater.
• The term "chrysophyceae" should not be
confused with the term Chrysophyta,
which is more ambiguous.

55. Originally they were taken to include all such
forms except the diatoms and multicellular
brown algae, but since then they have been
divided into several different groups based
on pigmentation and cell structure.
They are now usually restricted to a core
group of closely related forms, distinguished
primarily by the structure of the flagella in
motile cells, also treated as an order
Chromulinales. It is possible membership will
be revised further as more species are
studied in detail.

56. Traits, locomotion, and
classification
Most members are unicellular flagellates, with
either two visible flagella, as in Ochromonas,
or sometimes one, as in Chromulina.
Some members are generally amoeboid, with
long branching cell extensions, though they
pass through flagellate stages as well.
Other members are non-motile. Cells may be
naked and embedded in mucilage, such as
Chrysosaccus, or coccoid and surrounded by a
cell wall, as in Chrysosphaera.

57. Evolution
Chrysophytes contain the pigment,
fucoxanthin. Because of this, they were once
considered to be a specialized form of
cyanobacteria. Because many of these
organisms had a silica capsule, they have a
relatively complete fossil record, allowing
modern biologists to confirm that they are, in
fact, not derived from cyanobacteria, but rather
an ancestor that did not possess the capability
to photosynthesize.