October 7 Flashcards
Organic Acid Metabolism
Many microbes can use organic acids as e- donors and carbon sources
*citric acid cycle/ Kreb’s cycle intermediates are common fermentation products
Syntrophy
two or more microbes cooperate to break down a compound neither could alone
Anaerobic Respiration
O2 is not the final e- acceptor
Involves ETC, oxidative phosphorylation, and some electrochemical gradients are used to power ATPase
Anaerobic Respiration Processes
- Nitrate reduction and denitrification
- Sulfate and sulfur reducers
- Acetogenesis
- Proton Reduction
- Other
Nitrate Reduction and Denitrification
Some proteobacteria
Inorganic compounds (N) are common e- acceptors
Denitrication: all products are gasses
Oxygen must not be present (it deactivates the required enzyme)
Sulfate and Sulfur Reducers
Inorganic sulfur is the final e- acceptor
Reduction of SO42- to H2S
Desulfovibrio
Acetogenesis
Acetogens and methanogens
CO2 e- acceptor
H2 e- donor
Acetogens convert CO2 to acetate
Acetogens
*Clostridium *
Convert CO2 to acetate
Methanogen
Obligate anerobe
Achaean (rumen)
Coenzyme F420 blue-green florescense
H2 e- donor, can be CO or others
Proton Reduction
Pyrococcus furiosis
grows best at 100°C
Archaean
Use sugars and small peptides as e- donor
Simplest aerobic repsiration mechanism–may resemble first anaerobic
Other e- acceptors
Ferric Iron (Fe3+) Geobacter reduces to produce ATP
Mn4+
ClO3-
Bioremediation
Use of microbes to degrade waste
Aerobic Chemoorganotrophic Process (description)
O2 is direct reactant
Enzyme: Oxygenase (mono and di)
Aerobic Chemoorganotrophic Process
- Lactic acid and mixed acid
- Methanotrophy and methylotrophy
- Sugar metabolism
- Organic acid metabolism
- Lipid metabolism
