Lecture Title : Fermentation – Glutamic
➢ Production of Glutamic acid
At the end of the session, student will be able to
➢ Explain the fermentation process of Glutamic acid
History of Glutamic acid
• The history of the first amino acid production dates back to 1908
when Dr. K. Ikeda, a chemist in Japan, isolated glutamic acid from
kelp, a marine alga, after acid hydrolysis and fractionation.
• He also discovered that glutamic acid, after neutralization with
castic soda, developed an entirely new, delicious taste.
• This was the birth of the use of monosodium glutamate (MSG) as a
• The breakthrough in the production of MSG was the isolation of a
specific soil-inhabiting gram-positive bacterium, Corynebacterium
glutamicum, by Dr. S. Ukada and Dr. S. Kinoshita in 1957.
• The successful commercialization of monosodium glutamate (MSG)
with this bacterium provided a big boost for amino acid production
and later with other bacteria like E. coli as well.
• It is an α-amino acid that is used by almost all living beings in the
biosynthesis of proteins.
• It is non-essential in humans, meaning the body can synthesize it. It
is also an excitatory neurotransmitter, in fact the most abundant
one, in the vertebrate nervous system.
• It serves as the precursor for the synthesis of the inhibitory gamma-
aminobutyric acid (GABA) in GABA-ergic neurons.
• It helps the nerve cells in the brain to send and receive information
from other cells.
• It may be involved in learning and memory.
• Glutamic acid is widely used in the production of monosodium
glutamate (MSG) which is commonly known as the ‘seasoning salt’.
• Monosodium glutamate is condiment and flavour-enhancing agent
• In hair loss and as anti ageing agent
• Glutamic acid commercial production by microbial fermentation
provides 90% of world’s total demand, and remaining 10% is met
through chemical methods.
• Organism – Corynebacterium glutamicum
• Fermentors as large as 500 m3
• Media composition – carbohydrate (glucose, molasses, sucrose,
etc.), peptone, inorganic salts and biotin.
• Biotin concentration in the fermentation medium has a significant
influence on the yield of glutamic acid
• Duration – 2-4 days
• The broth contains glutamic acid in the form of its ammonium salt.
• The bacterial cells are separated and the broth is passed through a
basic anion exchange resin.
• Glutamic acid anions get bound to the resin and ammonia is
• This ammonia can be recovered via distillation and reused in the
• Elution is performed with NaOH to directly form monosodium
glutamate (MSG) in the solution and to regenerate the basic anion
• From the elute, MSG may be crystallized directly followed by
further conditioning steps like decolourization and serving to yield a
food-grade quality of MSG.
• α-ketoglutaric acid serves as the precursor of glutamic acid and the
conversion of the α- ketoglutaric acid to glutamic acid occurs in
presence of enzyme glutamic acid dehydrogenase.
• It has been found that if penicillin is added in the medium, the
glutamic acid production can be increased manifold.