产甲烷菌与同型产乙酸菌.doc

产甲烷菌与同型产乙酸菌
Physiology and Diversity of Prokaryotes pmbio
Methanogens and
homoacetogens
Martin Knneke
com
Two types of carbon respiration
- Methanogenesis
- Homoacetogenesis
Low energy yield but
carbonate is almost
everywhere abundant
Alessandro Volta 1745-1827
Lake Maggiore Italy November 3 1776
Observation bustible air
Physiology and Diversity of Prokaryotes pmbio
Methanogens
BROCK Microbiology Chapter 13 17
CYPIONKA Grundlagender Mikrobiologie Chapter 15
Methanogens represent a large group of
anisms which share three features
Formation of methane as the major product of their
energy metabolism
They are strict anaerobes
They are members of the domain Archaea
The three domains of life
Lipid bonds in Bacteria Eukarya and Archaea
Etherlipids in Archaea
Side chains consist of repeating isoprene units
Structure of archaeal membranes
Glycerol-diether Glycerol-tetraether
Anaerobic degradation anic matter
Complex polymers
harides lipids proteins
Hydrolysis
Monomers
sugars fatty acids amino acids
Fermentation
Short chain fatty acids and alcohols H2 CO2
lactate butyrate propionate ethanol Formate
Secondary fermentativ
bacteria Acetate
Methanogenesis CO2 Methane
3 types for methanogenesis
Reaction G°′ kJmol of methane
Carbonate respiration
4 H CO CH 2 H O – 1356
2 2 4 2
4 Formate CH4 3 CO 2 H O – 1301
2 2
4 2-Propanol CO2 CH4 4 Acetone 2 H2O –365
2 Ethanol CO2 CH4 2 Acetate – 1163
pounds
Methanol H CH H O – 1125
2 4 2
4 Methanol 3 CH CO 2 H O – 1049
4 2 2
4 Methylamine 2 H O 3 CH CO 4 NH –750
2 4 2 4
2 Dimethylamine 2 H O 3 CH CO 2 NH –732
2 4 4
4 Trimethylamine 6 H O 9 CH 3 CO 4 NH –743
2 4 2 4
2 Dimethylsulfide 2 H O 3 CH CO H S –738
2 4 2 2
Acetoclastic
Acetate CH4 CO2 –310
Physiology and Diversity of Prokaryotes pmbio
Oxidation state
IV
Carbon dioxide CO
2
Formyl -COH
R