Maarg Manthan · Topic 11.23

Amino Acids, Vitamins and Sweeteners from Biotechnology

Science & Technology › Biotechnology – Applications · Topic 11.23

Many amino acids, vitamins and sweeteners are made industrially by microbial fermentation and enzyme reactions. Glutamic acid, used as the flavour enhancer monosodium glutamate, and lysine, added to animal feed, are produced by the bacterium Corynebacterium glutamicum. Vitamin B12 is made by bacteria such as Propionibacterium and Pseudomonas denitrificans, and riboflavin or vitamin B2 is made by the fungus Ashbya gossypii. Sweeteners include high fructose syrup, made with the enzyme glucose isomerase, and aspartame, which is built from two amino acids, aspartic acid and phenylalanine. Steviol glycosides from the stevia plant are a natural sweetener approved in India in 2011.

5 min read · UPSC Prelims · Science & Technology · Biotechnology – Applications

At a Glance

MSG source Corynebacterium glutamicum
Vitamin B12 Propionibacterium
Vitamin B2 Ashbya gossypii
Sweetener enzyme Glucose isomerase
Aspartame parts Aspartic acid and phenylalanine
Exam link UPSC Prelims, Science & Technology: Biotechnology – Applications

Where Does It Fit?

This topic follows food and beverage fermentation. It looks at the pure compounds, such as amino acids, vitamins and sweeteners, that industry now makes in fermenters for use in food, feed and medicine. Previous topic: Food and Beverage Fermentations: Microorganisms as Food, Enzymes in Food Processing. Next topic: Organic Acids and Polysaccharides Production.

Which Compounds Are Made and by Which Microbes?

Product	Microbe and use
Glutamic acid	Corynebacterium glutamicum. Monosodium glutamate enhances savoury taste. First isolated as MSG by Kikunae Ikeda of Japan in 1908
Lysine	Corynebacterium glutamicum. An essential amino acid added to cereal based animal feed
Phenylalanine	Made by engineered bacteria for aspartame
Vitamin B12	Propionibacterium shermanii and Pseudomonas denitrificans. Used for supplements and fortification
Riboflavin (B2)	Ashbya gossypii or Eremothecium ashbyii, a fungus. Used as a vitamin and food colour
Vitamin C	Chemical and microbial steps, from glucose via sorbitol with Gluconobacter, then conversion to ascorbic acid
Beta carotene	The fungus Blakeslea trispora or algae, as a source of provitamin A and colour

Which Sweeteners Come from Biotechnology?

High fructose corn syrup: starch is broken to glucose by amylases, and glucose isomerase turns part of it into fructose, which is sweeter than sugar
Aspartame: a dipeptide about 200 times sweeter than sugar, discovered in 1965 by James Schlatter, made from aspartic acid and phenylalanine
Stevia: steviol glycosides from leaves of Stevia rebaudiana, 200 to 300 times sweeter than sugar, with no calories
Xylitol and sorbitol: sugar alcohols made by hydrogenation or by microbes, used in sugar free products
Sucralose: a chlorinated sugar made by chemical processes, not by fermentation
Thaumatin and brazzein: sweet proteins from plants, now produced by recombinant microbes
Allulose: a rare sugar made by enzymes from fructose
Erythritol: a sugar alcohol made by fermentation with yeast

What Else Should You Remember?

Monosodium glutamate: used worldwide, and the Food Safety and Standards Authority of India requires a label statement that a product contains added MSG
Aspartame safety: in July 2023 the International Agency for Research on Cancer classified aspartame as possibly carcinogenic to humans, Group 2B, while the Joint FAO and WHO expert committee kept the acceptable daily intake at 40 mg per kg of body weight
Phenylketonuria: people with this inherited condition cannot process phenylalanine, so products with aspartame carry a warning
Stevia in India: the food regulator approved steviol glycosides as a sweetener in 2011, and farmers grow stevia in several states
Sugar reduction: high sugar intake is linked to obesity and diabetes, so non-nutritive sweeteners are widely used
Essential amino acids: those that the body cannot make and must be taken in food, including lysine, methionine and phenylalanine
Fermentation advantages: fermentation gives the natural L form of amino acids, while chemical synthesis gives mixed forms
Metabolic engineering: strains are redesigned to channel more carbon to the wanted amino acid, as in Industrial Genetics and Microbial Ecology
Feed industry: lysine and methionine improve feed protein quality and growth of pigs and poultry
Global producers: China, Japan and Europe lead in amino acid fermentation, and India imports many of them
Fortification link: B12 and other vitamins are used in fortified foods, as in Single-Cell Protein Production and Food Fortification
Labelling: FSSAI rules require declaration of sweeteners and warnings for products with artificial sweeteners
Cost and scale: amino acid plants run for thousands of tonnes, so even a small gain in strain yield saves a large amount of money

Why Does It Matter for the Exam?

Match microbe with product: Corynebacterium, Propionibacterium, Ashbya
Sweeteners: aspartame, stevia, HFCS
Safety: phenylketonuria warning and IARC classification
Current affairs link: sugar tax debates and sweetener rules
Common errors: saying that aspartame is natural, or that sucralose is made by fermentation

As an analytical point, fermentation lets industry make food ingredients cleanly and at scale. Public health goals such as lower sugar intake need clear labels and consumer education, not only new sweeteners.

Why Is This Topic Important?

Microbes Product matches
Sweeteners Types and safety
Industry Feed and food

What Came Next?

The next topic covers organic acids and polysaccharides produced by microbes. Next topic: Organic Acids and Polysaccharides Production.

Key People and Terms

MSG Flavour enhancer
Essential amino acid Must come from diet
Dipeptide Two amino acid unit
Steviol glycoside Stevia sweet compound
HFCS High fructose corn syrup
PKU Phenylketonuria

Exam Corner

Points to Remember

MSG: Ikeda, 1908.
Aspartame discovered: 1965.
Stevia approved in India: 2011.
IARC aspartame class: 2B (2023).
Glutamate maker: Corynebacterium glutamicum.

Do Not Confuse With

Aspartame and sucralose Amino acid dipeptide versus chlorinated sugar
Stevia and aspartame Plant extract versus synthetic dipeptide
Lysine and glutamic acid Essential amino acid versus flavour related one

Memory Hook

Glutamate from Corynebacterium, B12 from Propionibacterium, B2 from the fungus; aspartame is two amino acids.

Mains Angle

Questions ask to match microbes with products and about sweeteners. These points help.

Process Fermentation advantages
Health Sugar reduction
Safety Labelling

A Question You May Face

An original practice question, not a past paper question.

“Discuss the role of fermentation in producing amino acids, vitamins and sweeteners, and the health issues linked to artificial sweeteners.”

How to Answer

Products Amino acids, vitamins.
Sweeteners HFCS, aspartame, stevia.
Issues Safety, labelling.
Way Evidence based rules.

GS Relevance

Prelims: microbes and products, sweeteners, MSG, aspartame. GS Paper 3: biotechnology, food processing, health and food safety.

Frequently Asked Questions

Which microbe is used to produce glutamic acid and lysine?

The bacterium Corynebacterium glutamicum is used industrially to produce glutamic acid, which is sold as monosodium glutamate flavour enhancer, and lysine, an essential amino acid added to animal feed. The bacterium was found in Japan in the 1950s and has been improved by genetic and metabolic engineering.

How is vitamin B12 produced industrially?

Vitamin B12 cannot be made by plants or animals and is produced only by certain bacteria. Industrially it is made by fermentation with Propionibacterium shermanii or Pseudomonas denitrificans, then purified and used in supplements, fortified foods and injections for deficiency, which is common in vegetarians.

What is aspartame?

Aspartame is an artificial sweetener, about 200 times sweeter than sugar, made from two amino acids, aspartic acid and phenylalanine. It was discovered in 1965. Products containing it must warn people with phenylketonuria, and in 2023 the International Agency for Research on Cancer classified it as possibly carcinogenic, though the daily intake limit was kept.

What is high fructose corn syrup?

High fructose corn syrup is a sweetener made by using amylase enzymes to break corn starch into glucose and then using the enzyme glucose isomerase to convert part of the glucose into fructose, which is sweeter. The syrup is widely used in soft drinks and processed foods.

Is stevia a natural sweetener?

Stevia is a natural sweetener obtained from leaves of the plant Stevia rebaudiana. Its sweet compounds, called steviol glycosides, are 200 to 300 times sweeter than sugar and give no calories. The Food Safety and Standards Authority of India approved their use in foods and drinks in 2011.

PYQ Practice — Statement Analysis

1 Corynebacterium glutamicum is used for the industrial production of glutamic acid.

True

Source of MSG.

2 Aspartame is made from aspartic acid and phenylalanine.

True

A dipeptide.

3 Sucralose is produced by microbial fermentation of glucose.

False

It is made chemically.

4 Vitamin B12 can be produced by plants.