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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.
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Extremely halophilicArchaea 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.
Thermoplasmatales Sulfolobales Thermoproteales Pyrodictiales Desulfurococcales Marine Crenarcheota Thermococcales Methanopyrales Methano-bacteriales -coccales -microbiales -sarcinales Archaeoglobales Extreme Halophiles Haloalkaliphiles Marine Euryarcheota Nanoarchaeota
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 Methanogens
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.
1 2 Evloluntionaryhistory of chloroplasts via endosymbiosis: The Symbiont 3
Origin of the palstids: Cyanobacteria (Bacteria, Prokaryotes) • Recipients: Various algae (Protists, Eukaryotes): • Glaucophyta • Cryptomonads • Rhodophyta • Chlorophyta • Euglenophyta • Chlorachniophyta • Chrysophyta • Heterocontae • Diatoms • Dinoflagellata (green) • Dinoflagellata (brown)