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FERMENTATION TECHNOLOGY

Fermentation - the process of chemical transformation of
organic substrate using enzymes of microorganisms
...

• Industries producing medicine, organic acids (butyric
acid, lactic acid, oxalic acid etc
...


Glycolysis and fermentation do not require oxygen (anaerobic)
...


Glycolysis: Embden-Meyerhof pathway
• Cytoplasm
• Anaerobic: Does not require oxygen
• Involves the splitting of a glucose molecule in a series of
ten steps which ultimately results in:
– two molecules of pyruvate
– and a net gain of two ATP
– and two NADH molecules

• The ten steps of glycolysis can be divided into three stages:
energy-investment, lysis, and energy-conserving

The 10 steps in Glycolysis
Energy investment stage:
• Step 1
...
The atoms of glucose-6-phosphate are
rearranged to form fructose-6-phosphate

• Step 3
...
Fructose 1,6-biphosphate is cleaved
form:
glyceralaldehyde 3- phosphate (G3P)
and dihydroxyacetone phosphate (DHAP)
• Step 5
...
Inorganic phosphates are added to the two G3P,
and two NAD+ are reduced to form 1,3-biphosphoglyceric
acid
• Step 7
...
The remaining phosphates are moved to the
middle carbons and a water molecule is removed from
each substrate to form phosphoenolpyruvic acid (PEP)
• Step 10
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Two pyruvate molecules
are formed
Note: Glycolysis provides relatively small amount of energy (ATP & NADH)
...
Electrons are removed from NADH during
fermentation, producing NAD+ which is needed to keep glycolysis going
...

•
• It reduces 2 molecules of NADP+ to NADPH and nets a
molecule of ATP from each molecule of glucose
...

• It catabolizes glucose to pyruvic acid (utilised in Kreb’s
cycle for fermentation) using different enzymes from
those used in either glycolysis or PPP
• It yields precursor metabolites and NADPH, and a single
molecule of ATP for each molecule of glucose

•
•
•
•

Glycolytic
Cytoplasm
Anaerobic
Different enzymes
– Pseudomonas
– Enterococcus

• End products
–
–
–
–
–

2-1 = 1 net ATP
NADPH
NADH
2 Pyruvic acids
H2 O

Bacteria: Pseudomonas, Rhizobium, Azotobacter, Agrobacterium,
Enterococcus faecalis

Fermentation Pathways

– A process by which living cell is able to obtain energy via the
breakdown of glucose and other simple sugar molecules
without requiring oxygen
– Results in the production of energy in form of two ATP
molecules and produce less energy than the aerobic process of
cellular respiration
– Pyruvic acid is reduced to form reduced organic acids or
alcohols
...

– Gases (CO2 and/or H2) may be released
• Fermentation pathways are useful as tools in biochemical
identification
...


Fermentation = metabolism of pyruvate in the absence of oxygen
...
Very important
because NAD+ must be recycled for glycolysis
...

The products are used
in
diagnosis
...

The production of
butyric
acid
by
Clostridium
perfringens
causes
severe tissue damage
of gangrene

Lactic acid fermentation
...

(a) Homolactic fermentation
...
Occurs in
some types of bacteria called lactobacilli, in streptococci, and in
mammalian muscle cells
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NADH from step 6 of glycolysis

NAD+ can now be reused in glycolysis,
step 6
...
e
...
Escherichia coli, Salmonella, Shigella
...
Pyruvic acid undergoes decarboxylation (CO2 is given
off) and reduction by NADH to form ethanol
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Fig
...
coli; Salmonella; Shigella etc
...


Requirement for fermentation process
• Specific strain of microorganisms or its mutants
capable of showing fermentation efficiently at a
much faster rate
...


for

optimal

rate

of

TYPE OF FERMENTAION
1
...
SUBMERGED FERMENTATION
3
...
AEROBIC FERMENTATION
5
...
Examples of such fermentation are
mushroom cultivation, mold-ripened cheeses, starter cultures etc
...

• Traditional substrates are several agricultural products eg- rice,
maize, soy bean, cassava etc
...

• Such substrate selectively supports mycelial organisms, which can
grow at high nutrients concentration and produce a variety of
extracellular enzymes
...

• Some food fermentations involving SSF: Wheat by Aspergillus,
Soybean by Rhizopus, Soybean by Aspergillus
Phases of solid state fermentation
The are 3 phases:
1
...
Liquid phase
3
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2) Microorganism is usually a filamentous fungus requiring
aerobic condition
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4) Cooking or chemical hydrolysis
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Factors Involved in SSF Process
Selection of micro-organisms
• This is one of the key factor for improved yields of the product
...

• Filamentous Fungi has shown better results growing in the solid
substrate fermentation
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• Substrate is chosen such a way that it should provide physical
support as well as nutrients to the growing culture
...
The second is for producing a
specific product from a suitable substrate
...
A lower chance of contamination due to low moisture levels
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2
...

3
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Disadvantage
• Heterogeneous nature of the media, due to poor mixing
characteristics
...

• Heat Transfer: One of the main difficulty is to control the temperature
during the fermentation process
...
•When the heat generated goes
beyond certain level, which will result in product denaturation and will
affect growth of microbe, ultimately ending up in reduction in yield and
quality of the product
...
Production of Industrial Enzymes
Ideally, almost all the known microbial enzymes can be produced
under SSF systems
...
using SSF systems
2
...
This Biocide bacterium can be obtained by fermentation,
either in liquid or semi-solid substrates found to act against
Spodoptera frugiperda (fall armyworm) in corn
...
Production of Renewable Energies
Renewable energies referring to the Biogas production by utilizing
the biomass from plant and animal sources when subjected to
anaerobic fermentation by the microbial flora, results in generation of
biogas which can be effectively utilized for running gas turbines, and
fuel cells
...
In Bioleaching
The recovery of metals from low grade black shale ore was attempted
by employing microbial samples using different organic wastes as
substrates
...
Media
components containing glucose (standard medium) and molasses etc
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5
...
A
biosurfactant accelerates the process of degradation of pollutant
composites
...


SUBMERGED FERMENTATION

• In the submerged process, the substrate used for fermentation is
always in liquid state which contains the nutrients needed for growth
...

• Submerged fermentation is a method of manufacturing
biomolecules in which enzymes and other reactive compounds are
submerged in a liquid such as alcohol, oil or a nutrient broth
...
The bioactive compounds are secreted into the fermentation
broth
...

• This fermentation technique is best suited for microorganisms such
as bacteria that require high moisture
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• SmF is primarily used in the extraction of secondary metabolites
that need to be used in liquid form

Application of computer in fermentation
They are three distinct areas of computer function;
process data
...


Data analysis
...
• There is an interface between the sensors
and the computer
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DATA ANALYSIS [Reduction of logging data]- Data reduction is performed by the data
analysis system ,which is a computer program based on a series of selected mathematical
equation
...

PROCESS CONTROL - Process control is also a performed computer program • Signals from
the computer are fed to pumps ,valves or switches via the interface
...
DDC-Direct Digital Control
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SSC-Supervisory Set-point Control
...
• SSC; the
use of independent controller to manage all control function of a fermenter and the computer
communicates with the controller only to exchange information
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g
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