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Extremely halophilic Archaea require large amounts of NaCl for growth. These organisms accumulate large levels of KCl in their cytoplasm as a compatible solute. These salts affect cell wall stability and enzyme activity. - PowerPoint PPT Presentation
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• Extremely halophilic Archaea require large amounts of NaCl for growth. • These organisms accumulate large levels of KCl in their cytoplasm as a compatible solute. These salts affect cell wall stability and enzyme activity. • The light-mediated proton pump bacteriorhodopsin helps extreme halophiles make ATP.
ThermoplasmatalesThermococcalesMethanopyrales
Methano-bacteriales-coccales-microbiales-sarcinales
Archaeoglobales Extreme Halophiles Haloalkaliphiles Marine Euryarcheota
Sulfolobales ThermoprotealesPyrodictialesDesulfurococcalesMarine Crenarcheota
Methanogens• Microbes that produce CH4
– Found in many diverse environments
– Taxonomy based on phenotypic and phylogenetic features
– Process of methanogensis first demonstrated over 200 years ago by Alessandro Volta
Methanogenesis
• The biological production of CH4 from either CO2 plus H2 or from methylated organic compounds.
• A variety of unique coenzymes are involved in methanogenesis• The process is strictly anaerobic. • Energy conservation in methanogenesis involves both proton and sodium ion gradients.
• Diversity of Methanogens– Demonstrate diversity of cell wall
chemistries
• Pseudomurein (e.g., Methanobacterium)
• Methanochondroitin (e.g., Methanosarcina)
• Protein or glycoprotein (e.g., Methanocaldococcus)
• S-layers (e.g., Methanospirillium)
• Substrates for Methanogens– Obligate anaerobes
– 11 substrates, divided into 3 classes, can be converted to CH4 by pure cultures of methanogens
• Other compounds (e.g., glucose) can be converted to methane, but only in cooperative reactions between methanogens and other anaerobic bacteria
Methanogenesis
1 – Methanofuran: CO2
activation
2 – Methanopterin: CO2 CHO methyl
3 – COM CHO CH3
4 – COM + COB + F430
methylreductase
5 – CH3 Methane
• Although hyperthermophiles live at very high temperatures, in some cases above the boiling point of water, there are temperature limits beyond which no living organism can survive. • This limit is likely 140–150°C. Hydrogen (H2) catabolism may have been the first energy-yielding metabolism of cells.
Evloluntionary history of
chloroplasts via endosymbiosis:
TheSymbiont
1
2
3
Origin of the palstids: Cyanobacteria (Bacteria, Prokaryotes)
Recipients: Various algae (Protists, Eukaryotes):
1. Glaucophyta 2. Cryptomonads 3. Rhodophyta 4. Chlorophyta 5. Euglenophyta6. Chlorachniophyta7. Chrysophyta8. Heterocontae9. Diatoms10. Dinoflagellata (green)11. Dinoflagellata (brown)