Industrial production of chemical acids glutamic acid
Department of biotechnology
Industrial production of chemical acids:
Amino acids have always played an important role in biology
of life, in biochemistry and in (industrial) chemistry.
Amino acids are the building blocks of proteins and they play
an essential role in the metabolism regulation of living
Large scale chemical and microbial production processes
have been commercialised for a number of essential amino
Current interest in developing peptide-derived chemo-
therapeutics has heightened the importance of rare and non-
proteinogenic pure amino acids.
Amino acids are versatile chiral (optically active) building blocks
for a whole range of fine chemicals.
Amino acids are, therefore, important as nutrients (food),
seasoning, flavourings and starting material for pharmaceuticals,
cosmetics and other chemicals.
Amino acid can be produced by :
Isolation from natural materials
Importance of Amino acids
Glutamic acid is an α-amino acid that used in
biosynthesis of proteins.
It contains an α-amino group which is in the
An α-carboxylic acid group which is in the
And a side chain carboxylic acid.
Polar negatively charged (at physiological pH), aliphatic
It is non-essential in humans, meaning the body can
As flavor enhancer, to improve flavor.
As nutritional supplement.
As flavor enhancer: in soft drink and wine.
As Hair restorer: in treatment of Hair Loss.
As Wrinkle: in preventing aging.
As nutritional supplement: in feed additive to enhance nutrition.
As intermediate: in manufacturing of various organic chemicals.
Biosynthesis of Glutamic acid
Reactants Products Enzymes
Glutamine + H2O → Glu + NH3 GLS, GLS2
NAcGlu + H2O → Glu + Acetate (unknown)
α-ketoglutarate + NADPH + NH4
+ → Glu + NADP+ + H2O GLUD1, GLUD2
α-ketoglutarate + α-amino acid → Glu + α-oxo acid transaminase
1-pyrroline-5-carboxylate + NAD+ + H2O → Glu + NADH ALDH4A1
N-formimino-L-glutamate + FH4 ⇌ Glu + 5-formimino-FH4 FTCD
An amino acid precursor is converted to the target amino acid using 1 or 2 enzymes.
Allows the conversion to a specific amino acid without microbial growth, thus
eliminating the long process from glucose.
Raw materials for the enzymatic step are supplied by chemical synthesis.
The enzyme itself is either in isolated or whole cell form which is prepared by
Industrial Production and use of Microorganisms
Microorganisms, typically grown on a large scale, to produce products or
carry out chemical transformations.
The glutamic acid is produced through the fermentation process
Major organism used is Corynebacterium glutamicum .
Classic methods are used to select for high-yielding microbial variants.
Properties of a useful industrial microbe include
Produces spores or can be easily inoculated.
Grows rapidly on a large scale in inexpensive medium.
Produces desired product quickly.
Should not be pathogenic.
Amenable to genetic manipulation.
The manufacturing process of glutamic acid by fermentation
b. crude isolation,
c. purification processes.
There are 4 types of fermentation are used:
(1) Batch Fermentation.
(2) Fed-batch Fermentation.
(3) Continuous Fermentation.
Industrial production of glutamic acid
Widely use in the production of most of amino acids.
Fermentation is a closed culture system which contains an
initial, limited amount of nutrient.
A short adaptation time is usually necessary (lag phase) before
cells enter the logarithmic growth phase (exponential phase).
Nutrients soon become limited and they enter the stationary
phase in which growth has (almost) ceased.
In glutamic acid fermentations, production of the acid normally
starts in the early logarithmic phase and continues through the
For economical reasons the fermentation time should be
as short as possible with a high yield of the amino acid at
A second reason not to continue the fermentation in the
late stationary phase is the appearance of contaminant-
The lag phase can be shortened by using a higher
concentration of seed inoculum.
The seed is produced by growing the production strain in
flasks and smaller fermenters.
(2) Fed-batch fermentation
Batch fermentations which are fed continuously, or
intermittently, with medium without the removal of fluid.
In this way the volume of the culture increases with time.
The residual substrate concentration may be maintained at a very
This may result in a removal of catabolite repressive effects and
avoidance of toxic effects of medium components.
The feed rate of the carbon source (mostly glucose) can be used
to regulate cell growth rate and oxygen limitation,especially when
oxygen demand is high in the exponential growth phase.
(3) Continuous fermentation
In continuous fermentation, an open system is set up.
Sterile nutrient solution is added to the bioreactor
And an equivalent amount of converted nutrient
solution with microorganisms is simultaneously
removed from the system.
Natural product such as sugar cane is used.
Then, the sugar cane is squeezed to make molasses.
The heat sterilize raw material and other nutrient are put
in the tank of the fermenter.
The microorganism (Corynebacterium glutamicum)
producing glutamic acid is added to the fermentation broth.
The microorganism reacts with sugar to produce glutamic
Then, the fermentation broth is acidified and the glutamic
acid is crystallized.
Industrial production of glutamic acid
Separation and purification
After the fermentation process, specific method is require to separate and
purify the amino acid produced from its contaminant products, which include:
The glutamic acid crystal is added to the sodium hydroxide solution
and converted into monosodium glutamate (MSG).
MSG is more soluble in water, less likely absorb moisture and has
strong umami taste.
The MSG is cleaned by using active carbon, which has many micro
holes on their surface.
The clean MSG solution is concentrated by heating and the
monosodium glutamate crystal is formed.
The crystal produce are dried with a hot air in a closed system.
Then, the crystal is packed in the packaging and ready to be sold.
Separation and purification of Glutamic acid
Q1 What are the types of fermentation that used in production of
amino acids, explain one of them.
Q2 Which type of Microorganisms used in production of glutamic acid,
discuss in brief the advantages of using microbes in production process.