Amino Acid Production
In recent years, there has been a rapid development of amino acid production by microbial fermentation. Large number of bacteria are now known to produce certain amino acids such as glutamic acid, lysine tryptophan, threomine, etc. on commercial scale. The major advantage of the amino acid production by microbial fermentation are that amino acids so produced are biologically active forms of amino acids (L-forms); and the cheap raw materials used thereby allow the low price of amino acids.
Glutamic acid fermentation was first harnessed in Japan, using Brevibacterium. However, many microorganisms such as Micrococcus, Arthrobacter, Brevibacterium, Corynebacterium glutamicum have been found to be superior and are used for the commercial production of glutamic acid. Glutamic acid production by microbial fermentation provides 90% of world's total demand, and remaining 10% is met through chemical methods. The raw materials used include 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. Fermentation completes within 2-4 days and the yield is considered as high as 50 mg/ml of glutamic acid.
α-ketoglutaric acid serves as the precursor of glutamic acid and the conversion of the a-ketoglutaric acid to glutamic acid occurs in presence on enzyme glutamic acid dehydrogenase. It has been found that if penicillin is deed in the medium, the glutamic acid production can be increased manifold.
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, it find its greatest use as a common ingredient in convenient food-stuffs