Magallanes CampusMagallanes, Sorsogon

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!

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

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

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 .

!!!

Importance2) 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

Cyanobacteria Characteristics

- Pigments – chl a, phycobiliproteins

- phycoerythrin- phycocyanin * BlueGreen

Color- allophycocyanin

- Storage – glycogen- Cell Walls – amino acids, sugars

Habit – success due to ability tolerate a wide range of

conditions

• Marine – littoral and pelagic• Fresh Water• Hot Springs• Terrestrial – soil flora

Advantage for Cyanobacteria

• Can live in fluctuating environments of aerobic and anaerobic with light present.

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

Movement

• No flagellae or structures to enhance movement

A) Excrete mucilage – jet propulsion, gliding

B) Helix – fibers send waves of contraction Spirulina

Spirulina

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

Anabaena with a heterocyst

- common bloom forming species with nutrient loads

Lyngbia martensiana

Releases chemicals causing dermatitis

Asexual Reproduction- Hormogonia formation -

- Endospore / Akinete formation -

- Fragmentation –

- Exospore

Asexual ReproductionHormogonia – short piece of trichome

found in filaments. It detaches from parent filament and glides away

Hormogonia

Oscillatoria with hormogonia

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

Oscillatoria (filamentous) with hormogonia

Asexual ReproductionAkinete – thick walled resting spore

A - akineteH

Akinete

Asexual ReproductionAkinete – 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

Asexual ReproductionFragmentation - fragmentation

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

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

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

Pellicle

Eudorina Gonium

Euglena

Volvox, fluorescence microscopy

Dinoflagellates

•Pyrrhophyta is the phylum name of the dinoflagellates.

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!

Not related to Dinosaurs

• The prefix Dino means whirling flagella. The Dinoflagellates are said to of out dated the Dinosaur

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

Anatomy

• This is the anatomy of a Dinoflagellate.

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.

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.

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.

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.

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

• 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.

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.

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.

EvolutionChrysophytes 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.