Fermentation Flashcards
the bulk of the ATP payout is produced by….depends on…why
ETC
O2
final e acceptor
ATp production that does not need O2
Fermentation
Anaerobic respiration
Aerobic respiration
Glycolysis,krebs,ETC
Is ETC used in absence of O2?
Yes but final e acceptor can be sulfate
…and…begin with glycolysis
but in…pyruvate is further used
cellular respiration
fermentation
fermentation
so fermentation is an extra step after…in yeast…in muscles…
glycolysis
alcohol
lactic acid
…utilises inorganic electron donor
chemolithotrophy
The goal of fermentation is..
NAD+ regeneration from NADH to allow glycolysis to continue
An opposite to aerobic and anaerobic respiration , fermentation an …..
through …
energetically weak
Substrate-level phosphorylation
Substrate-level phosphorylation
occurs in
The synthesis of ATP by the direct transfer of
phosphate group from a high energy intermediate substrate to ADP energy generated from the reaction itself
glycolysis,Krebs,fermentationfew ATP
Oxidative phosphorylation
synthesis of ATP by phosphorylation of ADP
energy is obtained by electron transport
using oxygen
high ATP
aerobic vs anaerobic respiration vs fermentation
ATP> glycolysis,krebs,ETC
ATP>Glycolysis,ETC
ATP>glycolysis ONLY
…..decrease in krebs products with O2 absence
60%
organic compound fate
fermentation
ETC and O2 (aerobic)
ETC and no O2 (anaerobic)
substrate level phoshorylation numbers
krebs >1
glycolysis>2
phosphorylation
In organic phosphate from environment+ADP
Fermentation definitions
extractng energy from carbs with O2 absence
microorganisms to make useful products
Pasteur effect
oxygen> aerobic and max ATP, minimizing fermentation products
no O2> fermentation
Alcohol fermentation per 1 pyruvate
1.pyruvate loses carboxyl group»acetyaldehyde+CO2
2.catalyzed by pyruvate decarboxylase (MG and thiamine pyrophosphate)
3.acetyaldehyde(+H from NADH)>ethanol
NADH>NAD+
4.Catalyzed by alcohol dehydrogenase
Ethanol above …. is toxic to yeast, so the natural level of alcohol in wine can only reach.
12%
Fermentation in baking
dough rises due to CO2 and ethanol evaporates
energy production in fermentation
glycolysis
Lactic acid fermentation
pyruvate+NADH»lactate
lactate dehydrogenase
lactate is
deprotonated form of lactic acid
muscle and yogurt is
lactic acid fermentation
Crabtree effect
why
high glucose even in O2 presence >fermentation
fast ATP production+metabolites (aa,lipids)
ethanol as defense mechanism
where pro vs eu?
glycolysis
TC
Fermentation
cytoplasm
Plasma membrane-mitochondria
cytoplasm
Glycolysis
Glycolysis>Krebs
Glycolysis>ETC
Glycolysis>Fermentation
2ATP
4ATP
32-34
2(of glycolysis)
Fermentation system depends on:
1.Type of Fermentation process
2. Operating mode
3. Fermentor design
4. Physical factors
5. Chemical factors
Fermentation process types
Solid state, microorgansims grow on solid media, substrate (antibiotics and enzymes)
submerged, enzymes and other reactive compounds submerged in liquid media (industrial manufacturing)
solid state adv and dis
environmentally friendly
many substrate options
low cost
high yield
slow no detailed monitoring
solid state steps
- Pre-treatment of substrate raw materials to enhance microbial growth (Particle size reduction, pH adjustment)
- Hydrolysis of polymeric substrates
- fermentation
- Separation and purification
…is a must in submerged for equal distribution
Agitation
Methods of carrying out submerged fermentation
batch, continuous or fed-batch
steps of submerged
prepare media
sterilsie
inoculum
monitor
control
cell recovery
purification
adv and dis of submerged
short time-high yield
easier purification and control
expensive-complex machines
batch
closed system,discontinuous, nutrients depleted
(organism+substrate no interferance)
batch steps
media added,sterilisation,inoculum,fermentation,harvesting
batch adv and dis
low contamination,easy to operate, high raw material conversion,controlled growth
build up of toxic metabolites
must be emptied and cleaned
continuous
open system
nutrients added
cells removed
constant volume
log phase always
continuous adv and dis
max and long term product synthesis,economically competitive
stable quality
higher productivity
contamination
genetic drift
difficult to control growth
fermentor vs fermenter
Fermentor: is the vessel where fermentation happens
Fermenter: bacterium or yeast, or an
enzyme.
Fed Batch
semi open system
end of lag nutrients added
increasing volume
fed batch adv and dis
increasing controlled yield
fermentation is limited by:
fermentor volume
toxics accumulation
contamination risk
no nutrients addition
volume increases
waste removal
highest contamination
lowest contamination
only log
all phases
shortest log
longest log
constant bacteria density
highest yield
batch
fed-batch
continuous
continuous
batch
continuous
batch and fed batch
batch
continuous
continuous
continuous
Fermentor design
- Agitation
- Aeration (aerobic fermentors)
- Regulation of chemical and physical factors like
temperature, pH, pressure, aeration, and nutrients - Sterilization
- Withdrawal of cells
