Diese Präsentation wurde erfolgreich gemeldet.
Die SlideShare-Präsentation wird heruntergeladen. ×

Cyanobacteria lecture

Nächste SlideShare
Cyanobacteria lecture
Cyanobacteria lecture
Wird geladen in …3

Hier ansehen

1 von 37 Anzeige

Weitere Verwandte Inhalte

Diashows für Sie (20)

Ähnlich wie Cyanobacteria lecture (20)


Aktuellste (20)

Cyanobacteria lecture

  1. 1. Cyanobacteria THE FIRST ALGAE!!!!! By shivang jindal
  2. 2. Evolution <ul><li>Old 3.5 billion years </li></ul><ul><li>Dominated as biogenic reefs </li></ul><ul><li>During Proterozoic – Age of Bacteria (2.5 bya – 750 mya) they were wide spread </li></ul><ul><li>Then multicellularity took over </li></ul><ul><li>Cyanobacteria were first algae! </li></ul>
  3. 3. Cyanobacteria terminology - Division Cyanophyta - Cyanobacteria ‘formerly known as’ Blue Green Algae - Cyano = blue - Bacteria – acknowledges that they are more closely related to prokaryotic bacteria than eukaryotic algae
  4. 4. Bacteria Archeae Other Eukaryotes Animalia Fungi Green Plants Red Algae Prokaryotes Eukaryotes
  5. 5. Cyanobacteria Archeae Brown Algae Fungi Green Plants Red Algae BOTANY Diatoms
  6. 6. Cyanobacteria <ul><li>Microscopic organisms </li></ul><ul><li>Found in marine sediments and pelagic zone, freshwater lakes, soils, </li></ul><ul><li>Live in extreme environments – chemically and temperature. </li></ul>
  7. 7. Importance <ul><li>1) First organisms to have 2 photosystems and to produce organic material and give off O 2 as a bi-product. </li></ul><ul><li> Very important to the evolution of the earths’ oxidizing atmosphere . </li></ul>!!!
  8. 8. Importance <ul><li>2) Many – fix or convert atmospheric nitrogen into usable forms through Nitrogen Fixation when other forms are unavailable. </li></ul><ul><li>IMPORTANT because atmospheric N 2 is unavailable to most living organisms because breaking the triple bond is difficult </li></ul>N N
  9. 9. Cyanobacteria Characteristics - Pigments – chl a, phycobiliproteins - phycoerythrin - phycocyanin * Blue Green Color - allophycocyanin - Storage – glycogen - Cell Walls – amino acids, sugars
  10. 10. Forms <ul><li>Unicell – with mucilaginous envelope </li></ul><ul><li>Colonies – </li></ul><ul><li>Filaments – uniserate in a single row </li></ul><ul><li>- OR - multiserate – not TRUE branching when trichomes are > 1 in rows </li></ul>
  11. 11. Features Trichome – row of cells Mucilaginous sheath – layer of mucilage outside of the cell wall. } Filament
  12. 12. Features Mucilaginous Sheath – Function – protects cells from drying and involved in gliding. Sheath is often colored: Red = acidic Blue = basic Yellow/Brown = high salt
  13. 13. Features Heterocyst – thick walled cell, hollow looking. Larger than vegetative cells. FUNCTION – provides the anerobic environment for N fixation. H- heterocyst
  14. 14. Anabaena Heterocyst Vegetative cells
  15. 15. Habit – success due to ability tolerate a wide range of conditions <ul><li>Marine – littoral and pelagic </li></ul><ul><li>Fresh Water </li></ul><ul><li>Hot Springs </li></ul><ul><li>Terrestrial – soil flora </li></ul>
  16. 16. Heterocyst <ul><li>Larger than vegetative cells </li></ul><ul><li>Hollow looking </li></ul><ul><li>Thick walled – doesn’t allow atmospheric gas to enter. </li></ul><ul><li>Photosynthetically inactive </li></ul><ul><li>No CO 2 fixation or O 2 evolution </li></ul><ul><li>Formation of heterocysts triggered by [molybdenum] and and low [nitrogen] </li></ul>
  17. 17. Nitrogen <ul><li>Nitrogen is a limiting nutrient necessary for the production of amino acids = building blocks of life. </li></ul>
  18. 18. Nitrogen Fixation <ul><li>ONLY cyanobacteria and prokaryotic bacteria can FIX nitrogen. </li></ul><ul><li>Of these two only CYANOBACTERIA evolve OXYGEN during photosynthesis </li></ul><ul><li>Important because nitrogenase (enzyme involved in fixing nitrogen) is INACTIVATED by O 2 . </li></ul>
  19. 19. Mechanisms to Separate Nitrogenase from Oxygen <ul><li>Heterocyst (spatial) </li></ul><ul><li>OR </li></ul><ul><li>Fix Nitrogen in the DARK but not LIGHT – found in non-heterocystic cyanobacteria (temporal) </li></ul>
  20. 20. AEROBIC <ul><li>CO 2 + H 2 O -----------  CH 2 O (sugar) +O 2 </li></ul><ul><li>Electrons for PS1 come from PS2 which evolves oxygen (splitting of water) </li></ul>LIGHT
  21. 21. ANAEROBIC in the presence of sulfer <ul><li>2H 2 S + CO 2 --------  CH 2 O +2S + H 2 O </li></ul><ul><li>H 2 S is the electron donor – so the reaction does not produce oxygen. </li></ul>
  22. 22. Advantage for Cyanobacteria <ul><li>Can live in fluctuating environments of aerobic and anaerobic with light present. </li></ul>
  23. 23. Cyanotoxins in Cyanobacteria <ul><li>Neurotoxins – block neuron transmission in muscles ( Anabaena, Oscillatoria ) </li></ul><ul><li>Hepatotoxins – inhibit protein phosphatase, cause liver bleeding. Found in drinking water. ( Anabaena, Oscillatoria, Nostoc ) </li></ul><ul><li>Eg. swimmers itch - Lygnbia </li></ul>
  24. 24. Movement <ul><li>No flagellae or structures to enhance movement </li></ul><ul><li>Excrete mucilage – jet propulsion, gliding </li></ul><ul><li>Helix – fibers send waves of contraction </li></ul>Spirulina
  25. 25. Spirulina <ul><li>filamentous </li></ul><ul><li>common in lakes with high pH </li></ul><ul><li>major food for flamingo populations </li></ul><ul><li>commercial food source </li></ul>
  26. 26. <ul><li>Anabaena with a heterocyst </li></ul><ul><li>common bloom forming species with nutrient loads </li></ul>
  27. 27. Lyngbia martensiana Releases chemicals causing dermatitis
  28. 28. Asexual Reproduction <ul><li>- Hormogonia formation - </li></ul><ul><li>- Endospore / Akinete formation - </li></ul><ul><li>Fragmentation – </li></ul><ul><li>Exospore </li></ul>
  29. 29. Asexual Reproduction <ul><li>Hormogonia – short piece of trichome found in filaments. It detaches from parent filament and glides away </li></ul>Hormogonia
  30. 30. <ul><li>Oscillatoria with hormogonia </li></ul><ul><li>short pieces of a trichome that become detached from the parent filament and glide away to form new filament. </li></ul>
  31. 31. Oscillatoria (filamentous) with hormogonia
  32. 32. Asexual Reproduction <ul><li>Akinete – thick walled resting spore </li></ul>A - akinete H
  33. 33. Akinete
  34. 34. Asexual Reproduction <ul><li>Akinete – thick walled resting spore </li></ul><ul><li>Function – resistant to unfavorable environmental conditions. </li></ul><ul><li>Appear as larger cells in the chain and different than heterocyst. Generally lose buoyancy </li></ul>A - akinete H
  35. 35. Asexual Reproduction <ul><li>Fragmentation - fragmentation </li></ul>
  36. 36. Oldest Fossils <ul><li>3.5by old carbonaceous microfossils S.Africa </li></ul><ul><li>3.4by old filaments and microbial fossils – W. Australia </li></ul><ul><li>3.4 by old stromatolites – S.Africa, Australia </li></ul>
  37. 37. Stromatolites – Shark Bay, W. Australia Cyanobacteria and Understanding the Past