Vitamin C, also known as ascorbic acid, can be produced through two main methods - the traditional Reichstein process involving chemical and microbial steps, or a newer two-stage fermentation process. The two-stage fermentation process replaces chemical reactions with a second fermentation step using Ketogulonicigenium vulgare and Bacillus spp. to convert L-sorbose to the intermediate 2-keto-L-gulonic acid. Vitamin C finds many uses as a food additive and dietary supplement for its antioxidant properties and role in immune function and collagen production. Biosynthesis of vitamin C is now favored over extraction from natural sources due to lower production costs and more sustainable production methods.

1. VITAMIN
PRESENTED BY-
KABERI NATH
ROLL NO- 17PBT206

2. CONTENTS
1. Introduction
2. Synthesis
a) Reichstein process
b) Two stage fermentation
3. Fermentation process
4. Uses
5. Biosynthesis over natural production
2

3. INTRODUCTION
 Vitamin C, also known as ascorbic acid and L-ascorbic acid, is a vitamin found
in food and used as a dietary supplement.
 Was discovered in 1912, isolated in 1928, and first made in 1933.
 Water-soluble vitamin.
 Occurs as a white or slightly yellow crystal or powder with a slight acidic taste.
 On exposure to light, it gradually darkens.
 In the dry state, it is reasonably stable in air, but in solution it rapidly oxidizes.
 Ascorbic acid (vitamin c) is freely soluble in water; sparingly soluble in alcohol;
insoluble in chloroform, in ether, and in benzene. 3

4.  The chemical name of ascorbic acid (vitamin c) is L-ascorbic acid (vitamin c) .
 The empirical formula is C6H8O6, and the molecular weight is 176.13.
 Vitamin C has been produced commercially by extraction from plants, by
chemical synthesis, by fermentation and by mixed fermentation/chemical
synthesis methods.
 The manufacture of vitamin C is now carried out in two ways-
1. traditional Reichstein process
2. newer two-stage fermentation process
4

5. REICHSTEIN PROCESS
5
• Chemical + microbial.
• Devised by Nobel Prize winner Tadeusz Reichstein and his colleagues in 1933 while working in
the laboratory of the ETH in Zürich.

6. 6

7. FERMENTATION PROCESS
 Submerged fermentation, aerobic, stirred
tank bioreactor
 Operation- fed batch
 Microorganism used- Gluconobacter
oxidans (Acetobacter suboxydans)
 Key enzyme- sorbitol dehydrogenase
 Nitrogen source- yeast extract
 pH 4-6
 Temparature 30°C
(R. GIRIDHAR and A.K. SRIVASTAVA,2001, Repeated fed-batch sorbose fermentation by
Gluconobacter oxydans; Chem. Biochem. Eng. Q)
7

8. DISADVANTAGES
Reichstein process is not eco friendly as-
1. Explosive gas (H2) is used.
2. Requires high pressure and temperature- energy intensive
3. Acetone and KMnO4 are toxic to environment
8

9. TWO-STAGE FERMENTATION PROCESS
 A second fermentation step
replaces the chemical
reactions used to produce
keto gulonic acid in the
Reichstein method.
 Mixed fermentation
consisting of
Ketogulonicigenium vulgare
and Bacillus spp. is
conducted to convert L-
sorbose to the intermediate
2-keto-L-gulonic acid (2-
KLG) in the two-step
fermentation process. 9

10. TWO-STAGE FERMENTATION PROCESS
 Developed in China and is used by all Chinese producers.
 Has lower fixed and capital costs, resulting in an overall production cost
saving of about a third compared with the Reichstein method.
 Makes less use of toxic solvents and reagents. There is, therefore, a reduction
in the cost of processing waste products.
Drawback-
 Yield is less compared to Reichstein process (60%)
10

11. FORMS OF VITAMIN C PRODUCED
 The synthesis of ascorbic acid was achieved by Reichstein in 1933, followed by industrial
production of ascorbic acid two years later by Roche.
 One of the world’s leading ascorbic acid production centers is that of DSM Nutritional
Products in Dalry, Scotland, UK.
 The world's two largest producers of ascorbic acid are BASF and Roche.
 Producers market vitamin C in various forms. These include powder and granular forms,
different purity levels, and chemical derivatives such as sodium ascorbate and calcium
ascorbate.
 BASF’s range of vitamin C products includes ascorbic acid in different particle sizes, sodium
ascorbate, and calcium ascorbyl-monophosphate, a product for the feed industry designed to
resist severe heat and pressure treatments.
 Some other minor speciality vitamin C products. These included stay-C, a low-solubility
product made by Roche, which is suitable for use in fish feeds.
11

12. USES
 Calcium, potassium and sodium salts of ascorbic
acid are used as food additives for their
antioxidant properties.
 Ascorbyl stearate or ascorbyl palmitate, which
are fat soluble esters of ascorbic acid, are used
for protecting fatty food from oxidation.
 It is used for enhancing the fermentation process
in food preparation.
 It is also used in chemical processes as reducing
agent.
 Vitamin C (ascorbic acid) is used to fix and keep
the red colour of meat products. 12
(Günter Pappenberger and Hans-Peter Hohmann; Industrial Production of L-Ascorbic Acid (Vitamin C) and D-Isoascorbic Acid; Adv Biochem Eng Biotechnol (2014) 143: 143–
188)

13.  Immune-stimulating effect.
 Inhibitor of histamine
 Can neutralize harmful free radicals
 Helps the body to make collagen
 Repairs and maintains bones and teeth
 Synthesizes neurotransmitters and blocks some of the damage caused by free radicals
Low levels of vitamin C have been associated with -
 Heart disease, hypertension, stroke, and atherosclerosis, as well as some cancers.
 Fatigue, lassitude, irritability, feeling run down, loss of appetite, low resistance to infection,
drowsiness and insomnia.
 A severe form of vitamin C deficiency is known as scurvy. 13

14. NEED FOR BIOSYNTHESIS
Till a few decades ago most added vitamins and related health compounds were indeed
industrially prepared via extraction technologies.
Switch from extraction technology over chemical synthesis towards industrial
biotechnology‐based processes-
1. The level of vitamins and related health compounds in the natural plant/animal source is
usually relatively low and fluctuates drastically.
2. Their organoleptic presentation and shelf ‐life is often not optimal.
3. Water‐soluble vitamins are easily lost by aqueous extraction or other manipulations of these
natural food vitamin sources.
4. They are based on renewable resources, deliver simple as well as very complex molecules
directly in a desirable chiral form and in an economically favourable way and they are
considered in society as clean, sustainable and reuse technologies.
(J L Revualta et al., Microbial biotechnology for the synthesis of (pro)vitamins, biopigments and antioxidants: challenges and opportunities; Microb Biotechnol.
2016 Sep; 9(5): 564–567.)
14

15. 15