Environments for extremely halophile Solar salt evaporation ponds Natural salt lakes Artificial saline habitats(surfaces of heavily salted food such as certain fish and meats) Require at least 1.5 M(9%) Nacl for growth Most species require 2-4 M(12-23%)NaCl for growth Some can grow at pH of 10-12 No harmful to human and animals
Environments for extremely halophile Solar salt evaporation ponds Natural salt lakes Artificial saline habitats (surfaces of heavily salted food such as certain fish and meats) Require at least 1.5 M (9%) NaCl for growth Most species require 2-4 M (12-23%) NaCl for growth Some can grow at pH of 10-12 No harmful to human and animals
Physiology of Extremely Halophilic Archaea All are chemoorganotrophs Most are obligate aerobes All require large amount of sodium for growth All stain gram negatively, binary fission growth Most are nonmotile Halobacterium and Halococcus contain large plasmids Peptidoglycan replaced by glycoportein in the cell wall Cellular components exposed to the external environment require high Nat for stability Cellular internal components require high K-t for stability Nat stabilize the cell walls
Physiology of Extremely Halophilic Archaea All are chemoorganotrophs Most are obligate aerobes All require large amount of sodium for growth All stain gram negatively, binary fission growth Most are nonmotile Halobacterium and Halococcus contain large plasmids Peptidoglycan replaced by glycoportein in the cell wall Cellular components exposed to the external environment require high Na+ for stability Cellular internal components require high K+ for stability Na+ stabilize the cell walls
Bacteriorhodopsin and Light-mediated ATP Synthesis H Bacteriorhodopsin x Out H H H ATPase H ADP+P
Bacteriorhodopsin and Light-mediated ATP Synthesis Bacteriorhodopsin
Methane-Producing Archaea: Methanogens Methane formation occurs under strictly anoxic conditions CO2-type substrates(CO2, HCoO and co) can be used as carbon sources Methyl substrates(CH3OH, CH3NH2*, (CH3)#, (CH3)3NH#, CH3SH, ( CH3)2S) are methanogenic carbon sources。 Acetotrophic substrates such as acetate can also be used to produce methane Three classes of methanogenic substrates are known and all release free energy suitable for ATP synthesis
Methane-Producing Archaea: Methanogens Methane formation occurs under strictly anoxic conditions. CO2-type substrates (CO2, HCOO- and CO) can be used as carbon sources. Methyl substrates (CH3OH, CH3NH2 + , (CH3)2NH+ , (CH3)3NH+ , CH3SH, (CH3)2S) are methanogenic carbon sources. Acetotrophic substrates such as acetate can also be used to produce methane. Three classes of methanogenic substrates are known and all release free energy suitable for ATP synthesis
Diversity and physiology of methanogenic Archaea 16S ribosomal RNA sequence analyses classify methanogen into seven major groups All methanogens use NH4* as a nitrogen source A few species can fix molecular nitrogen Nickel is a trace metal required by all methanogens, it is a component of coenzyme Factor430 Iron and Cobalt are also important for methanogens Pictures on the left: morphological diversity of methanogens
Diversity and Physiology of Methanogenic Archaea 16S ribosomal RNA sequence analyses classify methanogen into seven major groups All methanogens use NH4 + as a nitrogen source A few species can fix molecular nitrogen Nickel is a trace metal required by all methanogens, it is a component of coenzyme Factor430 Iron and Cobalt are also important for methanogens. Pictures on the left: morphological diversity of methanogens