Department of biotechnology

Industrial production of chemical acids:

glutamic acidpresented by

Essam Yahya

Introduction

Amino acids have always played an important role in biologyof life, in biochemistry and in (industrial) chemistry.

Amino acids are the building blocks of proteins and they playan essential role in the metabolism regulation of livingorganisms.

Large scale chemical and microbial production processeshave been commercialised for a number of essential aminoacids.

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 blocksfor 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 : Chemical synthesis

Isolation from natural materials

Fermentation

Chemo-enzyme methods

Importance of Amino acids

Glutamic acid

Glutamic acid is an α-amino acid that used in biosynthesis of proteins.

It contains an α-amino group which is in the protonated −NH3+.

An α-carboxylic acid group which is in the deprotonated −COO.

And a side chain carboxylic acid.

Polar negatively charged (at physiological pH), aliphatic amino acid.

It is non-essential in humans, meaning the body can synthesize it.

Glutamic Acid Food Production:

As flavor enhancer, to improve flavor.

As nutritional supplement.

Beverage

As flavor enhancer: in soft drink and wine.

Cosmetics

As Hair restorer: in treatment of Hair Loss.

As Wrinkle: in preventing aging.

Agriculture/Animal Feed

As nutritional supplement: in feed additive to enhance nutrition.

Other Industries

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 microbial fermentation.

Industrial Production and use of Microorganisms

Industrial microbiology 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.

Corynebacterium glutamicum

The manufacturing process of glutamic acid by fermentation comprises :-

a. 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

(1)Batch Fermentation

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 stationary phase.

For economical reasons the fermentation time should be as short as possible with a high yield of the amino acid at the end.

A second reason not to continue the fermentation in the late stationary phase is the appearance of contaminant-products.

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 low level.

This may result in a removal of catabolite repressive effects and avoidance of toxic effects of medium components.

Oxygen balance.

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 continuously.

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 acid.

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:

Centrifugation.

Filtration.

Crystallisation.

Ion exchange.

Electrodialysis.

Solvent extraction.

Decolorisation.

Evaporation.

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.

Thank You