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.

Thermoplasmatales Thermococcales Methanopyrales Methano-bacteriales -coccales -microbiales -sarcinales Archaeoglobales Extreme Halophiles Haloalkaliphiles Marine Euryarcheota Sulfolobales Thermoproteales Pyrodictiales Desulfurococcales Marine Crenarcheota Nanoarchaeota

Methanogens Microbes that produce CH 4 –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 CH 4 from either CO 2 plus H 2 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 CH 4 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: CO 2 activation 2 – Methanopterin: CO 2 CHO methyl 3 – COM CHO CH 3 4 – COM + COB + F 430 methylreductase 5 – CH 3 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 (H 2 ) 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) Origin of the palstids: Cyanobacteria (Bacteria, Prokaryotes) Recipients: Various algae (Protists, Eukaryotes): Recipients: Various algae (Protists, Eukaryotes): 1.Glaucophyta 2.Cryptomonads 3.Rhodophyta 4.Chlorophyta 5.Euglenophyta 6.Chlorachniophyta 7.Chrysophyta 8.Heterocontae 9. Diatoms 10. Dinoflagellata (green) 11. Dinoflagellata (brown)