this is presentation on vitamin a production by the microorganism various microorganism produced vitamin a commercially by which we can obtain it easily and produced industrial application. what are the vitamin a classification and production
2. WHAT IS VITAMIN
The word "vitamin" comes from the Latin word
vita, means "life"
“Vitamins have been defined as organic compounds which
are required in tiny amounts to maintain normal health of
organisms’ cannot be synthesized in sufficient quantities
by an organism, and must be obtained from the diet.
Vitamin A is a fat-soluble vitamin, also known as retinol because it
produces pigments in the eye's retina
Fat-soluble vitamins are absorbed along with fats in the diet and can be stored in the
body's fatty tissue. They come from plant and animal foods or dietary supplements.
3. History of vitamin A production
The discovery of vitamin A may have stemmed from research dating
back to 1816, when physiologist François Magendie observed that dogs
deprived of nutrition developed corneal ulcers and had a high mortality
rate. The "accessory factors" were termed "fat soluble" in 1918 and later
"vitamin A" in 1920.
In 1912, Frederick Gowland Hopkins demonstrated that unknown
accessory factors found in milk, other than carbohydrates, proteins,
and fats were necessary for growth in rats. Hopkins received a Nobel
Prize for this discovery in 1929.
6. Retinol (vitamin A alcohol) retinol plasma values:
15-30 mcg/dl in infants
30-90 mcg/dl in adults
This is an aldehyde form obtained by the
oxidation of retinol. Retinal and retinol are inter convertible
Retinal vitamin a aldehyde
A yellow, fat-soluble substance. It is the form of vitamin A absorbed
when eating animal food sources. Sources include cod liver oil, butter,
margarine, liver, eggs, cheese and milk.
Carotenes
Carotene is an orange photosynthetic pigment crucial for plant
photosynthesis. The orange colors of carrots, sweet potatoes and
cantaloupe melons come from its carotene content.
7. Two forms of vitamin A are available
in the human diet:
preformed vitamin A
• found in meat, poultry, fish, and dairy products.
provitamin A( beta carotene)
• is found in fruits, vegetables, and other plant-based products. The most common type of
provitamin A in foods and dietary supplements is beta-carotene.
Found in plant foods lt is cleaved in the intestine to produce two moles of retinal
Transport and storage of vit a
Liver stores 90% of vitamin A in the body in form of Retinyl palmitate
Reserve is adequate for several months, Transported via chylomicrons from intestinal
cells to the liver
Transported from the liver to target tissue as retinol,Free retinol is highly active but
toxic & therefore transported in blood stream in combination with retinol binding
protein
8. Role of vit A in body
Vitamin A in Vision
Helps to maintain the cornea
Conversion of light energy into nerve
impulses at the retina
Rhodopsin is a light-sensitive pigment
of the retina that contains a protein
called opsin.
9. Role of vit a in growth and differentiation of cell
Retinoic acid is necessary for cellular differentiation
• Important for embryo development, gene expression
• Retinoic acid influences production,structure, and function of epithelial cells that line the outside
(skin) and external passages (mucus forming cells) within the body
10. Daily requirment
Men and women – 750-1000 μg.
Pregnancy and lactation – 1000 μg.
Infants – 350 μg.
Children – 400-600 μg.
Vitamin A in Foods
Retinol is found in fortified milk, cheese, cream, butter,fortified margarine, and
eggs.
Beta-carotene Spinach and other dark green leafy vegetables (chlorophyll pigment
masks the color)
Deep orange fruits
Deep orange vegetables like squash, carrots, sweet potatoes
White foods are typically low in beta-carotene.
Vitamin A is poor in fast foods and foods with the xanthophyll pigments (beets,
corn).
Liver is rich in vitamin A.
11. Ocular
Night blindness.
xerophthalmia-
bitot’s spot-
keratomalacia-
Extra ocular
Retarded growth
Skin disorders
Effect on
reproductive
organs.
Effect on bone
Deficiency of vitamin A
Conjunctiva become dry, thick and wrinkled
Conjunctive keratinizes and develops
plaques- BITITS SPOT Grayish white triangular spots in
conjunctiva
Infection leads to corneal ulceration and
total blidness
12. Commercial production of beta carotene
Nowadays, carotenoids are valuable molecules in different industries such as
chemical, pharmaceutical, poultry, food and cosmetics. These pigments not only
can act as vitamin A precursors, but also they have coloring and antioxidant
properties
Carotenoids are naturally occurring lipid-soluble pigments, the majority being
C40terpenoids, which act as membrane-protective antioxidants scavenging O2 and peroxyl
radicals; their antioxidant ability is apparently attributed to their structure
Chemical synthesis generates hazardous wastes that can affect the environment. Unlike
these traditional methods, the microbial production of carotenoids shows great interest
and safety to use
Xanthophyllomyces dendrorhous developing reliable biotechnological processes. So,
yeasts are reliable microorganisms to produce carotenoids
Rhodotorula spp. This yeast, widely distributed in nature, can biosynthesize specific
carotenoids such as β -carotene, torulene and torularhodin, in different proportions
13. Bacteria have been reported as producers of cantaxanthin mainly, a carotenoid of interest in
poultry, fishery, cosmetics, medicine, pharmaceuticals and food industries. Among the most
studied carotenoids producers bacteria are Corynebacterium michiganense, Micrococcus roseus,
Brevibacterium spp., Bradyrhizobium spp., Gordonia jacobaea and Dietzia natronolimnaea
The general pathways for biosynthesis of carotenoid by yeasts and concluded that the
carotenoid biosynthesis pathway involves three general steps:
1) Synthesis begins with conversion of acetyl CoA to 3-hidroxy-3-methyl glutaryl-CoA (HMG-CoA),
catalyzed by HMG-CoA synthase. Then, HMG-CoA is converted in mevalonic acid (MVA), this is
the first precursor of terpenoid biosynthetic pathway. MVA is phosphorylated by MVA kinase and
decarboxylation; into isopentenyl pyrophosphate (IPP).
2) IPP is isomerized to dimethyllayl pyrophosphate (DMAPP) with the addition of three IPP
molecules to DMAPP, catalyzed by prenyl transferase into geranyl geranyl pyrophosphate
(GGPP). Condensation of two molecules of GGPP produces the phytoene (the first
C40 carotene of the pathway); which is subsequently desaturated to form lycopene.
3) Many cyclic carotenoids are derived from lycopene, as β -carotene, γ -carotene, Torulene,
Torularhodin and Astaxanthin when it undergoes many reactions.
14. The microbial production of carotenoids involved several steps:
Selection of the appropriate substrate . The raw materials utilized might or not be
pretreated depending on the fermentative capacity of the microorganism and the type of
enzymes produced.
Bioreactor. The bioreactor configuration and operational variables are crucial for the
maximum yields of the process.
Downstream processing. Production of intracellular pigments is limited by the complexity
of “downstream” processing. Cell disruption is a critical step to recover intracellular
compounds and it affects recovery yield and carotenoids properties.
15. Factors influencing the production of carotenoid in yeasts
•Carbon source Metabolism of yeasts acts depending on the kind of carbon source in the medium.
Glucose and other fermentable sugars are metabolized by the glycolytic pathway, and then an alcoholic
fermentation, even with oxygen.
•Light Microorganisms need to prevent themselves from the light that causes damage, and
carotenogenesis is a photoprotective mechanism Carotenoid production is affected positively by white
light, and carotenoid conc depends of the microorganism.
•Aeration carotenogenesis is an aerobic process, and the airflow rate in the yeast culture is an
essential factor to the substrate assimilation for the growth rate, cell mass And Also, decreasing
oxygen levels influences the production of carotenes or xantophylls, due to oxidation of carotenes in
Astaxanthin, Cantaxanthin and others.
Temperature It acts changing the biosynthetic pathways, biomass
production in Rhodotorula glutinis, reporting at 29 and 30°C the
maximum production,
. •Metal ions and salts (Ba, Fe, Mg, Ca, Zn and Co) have also STIMULATE PRODUCTION In the case of
Al3+ and Zn2+ a stimulatory effect on β -carotene and γ- carotene production was observed, while Zn2+ and
Mn2+ showed inhibitory effect on torulene and torularhodin production
