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DIVERSITY OF PHYTOPLANKTON CYANOBACTERIA

DIVERSITY OF PHYTOPLANKTON CYANOBACTERIA. MARINE BOTANY FALL 2009 Dr. Mitra. CYANOBACTERIA. Prokaryotic cells First algae to appear-fossil history-3.5 billion years Fossils of cyanobacteria--stromatolites. CHARACTERISTICS OF CYANOBACTERIA. Lack membrane-bound organelles

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DIVERSITY OF PHYTOPLANKTON CYANOBACTERIA

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  1. DIVERSITY OF PHYTOPLANKTON CYANOBACTERIA MARINE BOTANY FALL 2009 Dr. Mitra

  2. CYANOBACTERIA • Prokaryotic cells • First algae to appear-fossil history-3.5 billion years • Fossils of cyanobacteria--stromatolites

  3. CHARACTERISTICS OF CYANOBACTERIA • Lack membrane-bound organelles • Chloroplasts, mitochondria, ER, Golgi bodies are absent • Thylakoids are not organized—scattered. Thylakoids contain phycobilisomes-phycobilins. Chlorophyll a –imparts green color and phycocyanin (phycobilin) imparts blue color. Source: http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Cyanobacteria.htm

  4. CHARACTERISTICS OF CYANOBACTERIA • Thylakoids-phycobilisomes-phycobiliproteins • Phycobiliproteins-phycoerythin (PE), phycocyanin (PC), allophycocyanin (APC), phycoerythrocyanin (PEC). PC and APC are present in all cyanobacteria. Source: http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Cyanobacteria.htm

  5. DIVERSITY IN CYANOBACTERIA Nonfilamentous Filamentous with specialized cells Filamentous without specialized cells

  6. NONFILAMENTOUS CYANOBACTERIA • Solitary cells • Aggregations • Colonial—surrounded by mucilage. Gloeocapsa: Photo: Lesley Bensinger, Dr. Mitra’s Research Group

  7. FILAMENTOUS CYANOBACTERIA WITHOUT SPECIALIZED CELLS • Trichome-series of cells. Filament includes both sheath and cells. • Hormogonium-A short segment of the filament breaks off and forms a new filament. Photos by Lesley Bensinger (Dr. Mitra’s Research Group)

  8. HETEROCYSTOUS CYANOBACTERIA-FILAMENTS WITH SPECIALIZED CELLS heterocyst • Akinetes and Heterocysts • Akinetes-Thick-walled resistant stages that remain inactive for sometime. They germinate to form new filaments. • Heterocysts-Specialized cells for nitrogen fixation. akinete Photo: Dr. Mitra’s Research Group

  9. Nitrogen Fixation in a Heterocyst Biology of Algae: Sze

  10. CYANOBACTERIA-ECOLOGY • Photosynthetic • Fix Nitrogen • Tolerate a wide range of environmental conditions-low and high temperatures, extended periods of desiccation, low-high salt conditions.

  11. FLOATING AND SINKING Accumulation of polysaccharides Photosynthesis goes up Buoyancy increases Cells rise Gas vesicles collapse Increased vacuolation Buoyancy decreases Cells sink Photosynthesis decreases

  12. CYANOBACTERIA-ECOLOGYCYANOPHYTE BLOOM Nutrient and sediment loads Eutrophication Death of organisms Water quality deteriorates Development of opportunistic blue green algae Recycling of nutrients and pollutants in the ecosystem Anoxia Photosynthesis declines Increase in herbivore population Environmental conditions become unfavorable and cyanophyte species die and decompose Large biomass toxicity rises

  13. TOXINS IN CYANOBACTERIA • Neurotoxins--------Nervous system • Hepatotoxins (Microcystis, Nodularia)-------Affect liver • Anatoxin (Anabaena)----fatigue • Lyngbya----dermatitis

  14. CYANOBACTERIA-SOURCE OF FOOD Spirulina –65-71% of protein. This genus is a source of all eight amino acids needed by the body.  Specifically, Spirulina contains potassium, calcium, zinc, magnesium, manganese, selenium, iron, and phosphorus.  It is also rich in chlorophyll.  It can also be used as a pre-meal supplement. 

  15. SYMBIOSIS Cycas - Nostoc Photo: Lesley Bensinger, Dr. Mitra’s Research Group

  16. SYMBIOSIS Azolla (fern)-Anabaena (cyanobacteria) Source:http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/AZOLLABGA.jpg

  17. SYMBIOSIS LICHEN Source: http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/BlueLichen.jpg

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