The document discusses pigments found in algae. There are three main types of pigments - chlorophyll, carotenoids, and phycobilins. Chlorophyll is the primary photosynthetic pigment and comes in various forms, with chlorophyll a present universally. Carotenoids include carotenes like beta-carotene and xanthophylls like fucoxanthin. Phycobilins include phycocyanin which is blue and absorbs green/red, and phycoerythrin which is red. Different algal groups contain predominant combinations of these pigments, which contribute to their distinctive colors.

1. ALGAL PIGMENTS
UNDER SUPERVISION OF PRESENTED BY
Dr. K. SURESH KUMAR BRIJESH PRATAP SINGH
M.Sc 1st SEM

2. PIGMENTATION
 The colour of the algal thallus which varies in different classes is due to the
presence of definite chemical compounds in their cells,these are called
pigments.
 Each pigment has its own characteristic colour. The particular colour that a
thallus has is due to the predominance of one pigment in a combination of
several others.
 For example,brown algae have predominance of Fucoxanthin and phycophien
while red and blue green algae have excess of phycoerythrin and
phycocyanin pigment respectively.
 The pigment is one of the most important criteria used in
differentiation of classes in algae. All algal cell have a characteristic
colour due to presence of combination of pigments.
 As algae were initially and primarily separated on the basis of colour e.
g., green algae, red algae, brown algae or blue green algae etc.

3. There are three kinds of Pigments in Algae.
(I)Chlorophyll: It is green colouring matter and is
photosynthetic pigment.
 Pigments in algal cells are contained in plastids or
chromatophores which vary in shape in different groups.
(II)Carotenoid-They are unsaturated hydrocarbons and
are of two types
 (a)Carotene and (b)Xanthophylls.
• About five different carotenes are found in algal cells. There
is large number of xanthophylls in present in algal cells.
• Xanthophylls include Peridin, Myxoxanthin, Tetraxanthin,
Anthraxanthin and Fucoxanthin
(III)phycobilins-They are water soluble and are present in
Cryptophyta, Cyanophyta and Rhodophyta and are of two
types called phycocyanin and phycoerythrin.

4. CHLOROPHYLL
 It is a green colouring matter and
is photosynthetic pigments and in
solution they show the
phenomenon of fluorescence and
emit red light.
 Pigments in algal cells are
contained in plastid or
chromatophores, which vary in
shape in different groups. They are
fat soluble compound.
 The chlorophyll in algae are
chlorophyll ‘a’, ‘b’, ‘c’, ‘d’ and ‘e’ type.

5. Chl-a(C55H72O5N4Mg)
Chl-b
N N
CH2
CH3
CH3
CH3
N
H
O
N
O
CH3
H
COOCH 3
Mg
H
CH3
O
CH3 CH3
H
CH3
H
CH3
CH3
Chl-c( C35H30O5N4Mg)
N N
CH3
N
O
N
O
CH3
H
COOCH 3
Mg
CH3
OH
CH2
CH3
CH3
(C55H70O6N4Mg)

6.  Out of these chlorophyll-a is universally present in all the group
of algae whereas chlorophyll-b,c,d & e restricted distribution.
Chlorophyll ‘b’ is primary pigments of Chlorophyceae &
Euglenophyceae.
Chlorophyll ’c’ is found in Phaeophyceae & Cryptophyceae.
Chlorophyll ‘d’ is found in Rhodophyceae.
Chlorophyll ‘e’ is confined to tribonema of Xanthophyceae.

7. CAROTENOID
 Carotenoid: They are unsaturated hydrocarbons and are red, orange or
yellow tetraterpenoid.
 During the process of photosynthesis, they have functions in light
harvesting(as accessory pigments) and protect Chlorophyll molecules
from Photo-oxidation. are of two types
 (i) Carotenes and (ii) Xanthophylls.
(i)Carotenes: These are oxygen free alicyclic compounds, composed of
isoprene units.
 Absorb blue and green light and transmit yellow and red light
 About five different carotenes are found in algae are,
 α-carotene in Chlorophyceae, Cryptophyceae and Rhodophyceae.
 β-carotene in all algal groups except Cryptophyceae.
 ϒ-carotene and lycopene are found in Cholorophyceae.

8. CAROTENE(C40H56)
THE CHEMICAL STRUCTURE OF CAROTENE MOLECULE

9. (ii) Xanthophyll: they are formed by the incorporation of
molecular O2 in to carotene molecules.
 There is large number of xanthophylls in present in algal
cells. Xanthophylls include Peridin, Myxoxanthin,
Tetraxanthin, Anthraxanthin and Fucoxanthin.
 Many xanthophylls, common in higher plants(lutein,
violaxanthin & neoxanthin) are found in the members of
chlorophyceae & Phaeophyceae.
 Fucoxanthin is the main xanthophyll pigment of
phaeophyceae and diatoms whereas myxoxanthophyll,
myxoxanthin and oscilloxanthin are found only in
cyanophyceae.

10. PHYCOBILINS
 They are water soluble complexes of protein present in photosynthesis
tissue of plants.
 Like Chlorophyll,phycobilins are open tetrapyrrole, but do not
contains magnesium and phytol chain .
 The two classes of phycobilins are present in algae,
(i)Phycocyanin(blue pigments): they absorb green ,yellow and red
light and transmit blue colour.
• Phycocyanin are the principle pigments of blue green algae.
(ii)Phycoerythrin(red pigments)-they absorb blue, green and yellow
light and transmit red light.
• Phycoerythrin present abundantly in members of Rhodophyceae.
• They act as light harvesting pigments in photosynthesis and light
absorbed by then is transferred to chl-a thus like carotenoid,
phycobilins are also accessory pigments.

11. Chemical structure of Phycobilin

12. Division Common Name Major and accessory pigments
Chlorophyta Green Algae Chl-a and b,carotenes and xanthophylls
Charophyta Charophytes Chl-a and b
Euglenophyta Euglenoids Chl-a and b
Phaeophyta Brown Algae Chl –a and c, fucoxanthin
Chrysophyta Yellow-brown or
golden-brown
Chl-a andc, fucoxanthin
Cryptophyta Cryptomonads Chl-a and c, phycobilins
Rhodophyta Red algae Chl-a and d, Phycoerythrin and
phycocyanin
Cyanophyta Blue-green algae Chl –a,Phycocyanine and phycoerythrin

13. REFERENCE
 Algae: B. R. Vashishta
 A textbook of botony: Singh, Pandey, Jain
 Algae Anatomy, Biochemistry, and Biotechnology:
Laura Barsanti & Paolo Gualtieri