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FERMENTATIONS
Pasteur defined “FERMENTATION” as life in the absence of oxygen
Fermentations are nowadays defined as a processes that do not involve
electron transport chains that use oxygen, nitrate or other electron acceptors
The majority of fermentations generate ATP by substrate level phosphorylation
Microorganisms can be classified as
Facultative anaerobes
Strict anaerobes
Ethanol Fermentation
• Yeast
Bacteria
PULQUE
Zymomonas mobilis
LACTIC ACID FERMENTATION
Homofermentative pathway
HETEROFERMENTATIVE PATHWAY
BIFIDUM PATHWAY
In the presence of a fermetable sugar and L-malate, Leuconostoc, Lactobacillus
Carry out the malo-lactic fermentation:
Malic enzyme
Important in the reduction of wine acidity
Diacetyl and acetoin fermentation
Weak acids can act as uncouplers at low pH and
are useful as food preservers
BUTIRATE AND BUTANOL/ACETONE FERMENTATIONS
Linear and branched fermentative pathways
MIXED ACID FERMENTATION
METHANE FERMENTATION
ATP synthesis only occurs due to protonmotive force
A digestão anaeróbia
Reactores UASB par aprodução de metano
Firmicutes
1
2
Bacteroidetes
1
3
4
5
Spirochaetes
1
2
6
7
8
9
Proteobacteria &
Deferribacteres
1
10
11
12
13
Chloroflexi
1
2
14
15
16
17
18
Euryarchaeota
3
1
2
3