Monosodium Glutamate (MSG) Production by Fermentation

The umami flavor enhancer produced by bacterial fermentation

Food Processing & Preservation Global Industrial Scale $6.2 billion

Overview

Monosodium glutamate (MSG) is produced by aerobic fermentation of Corynebacterium glutamicum on sugar substrates, followed by crystallization of the sodium salt. Discovered by Kikunae Ikeda in 1908 as the compound responsible for umami taste, MSG is now the most produced amino acid worldwide. The fermentation process was developed in the 1950s, replacing the original hydrolysis of wheat gluten or soy protein. China produces over 60% of the world's MSG supply.

Chemical Process

Corynebacterium glutamicum is grown aerobically on glucose or cane molasses at 30-37 degrees C for 30-40 hours, secreting L-glutamic acid into the broth at concentrations up to 150 g/L. The broth is acidified to precipitate glutamic acid crystals at pH 3.2 (isoelectric point), which are then dissolved, neutralized with NaOH, and recrystallized as MSG monohydrate.

C₆H₁₂O₆ + NH₃ + O₂ →[C. glutamicum] HOOC-CH(NH₂)-CH₂-CH₂-COOH + CO₂ + H₂O
L-Glutamic acid + NaOH → MSG + H₂O

Raw Materials

  • Glucose or cane molasses — Corn wet milling or sugar refining (Carbon source)
  • Ammonium sulfate ((NH₄)₂SO₄) — Chemical synthesis (Nitrogen source)
  • Sodium hydroxide (NaOH) — Chlor-alkali process (Neutralization agent)

End Products

  • MSG monohydrate (C₅H₈NNaO₄·H₂O) — Flavor enhancer (umami) (Food-grade, >99% purity)
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Environmental Impact

Fermentation wastewater has high nitrogen and BOD content. The ammonium sulfate mother liquor from crystallization can be used as fertilizer. Modern plants achieve 85-90% substrate conversion, minimizing waste. Some facilities use biogas from wastewater treatment for energy recovery.

Safety Considerations

Recent Innovations

Metabolic engineering has produced C. glutamicum strains with glutamate yields exceeding 50% of theoretical maximum.
Continuous fermentation with cell recycling membrane bioreactors improves productivity and reduces batch turnaround time.

Production Scale

3500000

tons/year

$6.2 billion

market value

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Frequently Asked Questions

What industry uses Monosodium Glutamate (MSG) Production by Fermentation?
Monosodium Glutamate (MSG) Production by Fermentation is used in the food processing & preservation sector at global industrial scale scale.
What process is involved in Monosodium Glutamate (MSG) Production by Fermentation?
Corynebacterium glutamicum is grown aerobically on glucose or cane molasses at 30-37 degrees C for 30-40 hours, secreting L-glutamic acid into the broth at concentrations up to 150 g/L. The broth is acidified to precipitate glutamic acid crystals at pH 3.2 (isoelectric point), which are then dissolv
What is the economic significance of Monosodium Glutamate (MSG) Production by Fermentation?
Monosodium Glutamate (MSG) Production by Fermentation has a market value of $6.2 billion and annual production of 3,500,000 tons.
What is the environmental impact of Monosodium Glutamate (MSG) Production by Fermentation?
Fermentation wastewater has high nitrogen and BOD content. The ammonium sulfate mother liquor from crystallization can be used as fertilizer. Modern plants achieve 85-90% substrate conversion, minimizing waste. Some facilities use biogas from wastewater treatment for energy recovery.
What raw materials are used in Monosodium Glutamate (MSG) Production by Fermentation?
The main raw materials include: Glucose or cane molasses, Ammonium sulfate ((NH₄)₂SO₄), Sodium hydroxide (NaOH).