The document provides comprehensive information on the identification and characteristics of different types of algae, including planktonic, filamentous, and macroalgae, as well as their pigments and appearances. It classifies algae into categories such as green, blue-green, red, and brown algae, highlighting their morphological features and common examples. The process for sampling, fixing, staining, and examining algae under a microscope is also detailed.

1. IDENTIFICATION OF
ALGAE
B. LOKESHWARI
II M. Sc MICROBIOLOGY
SACRED HEART COLLEGE (AUTONOMOUS)
TIRUPATTUR

2. IDENTIFICATION OF ALGAE
• Algae can be of planktonic, filamentous or macroalgae
• Planktonic: Distributed through the water column, giving a color to the water.
• Filamentous: They are generally mat-like entanglements that show up on the
bottom or the surface of the water.
• Macro algae: grow up from the bottom of the system.

3. PLANKTONIC (DISCOLORATNIO OR SCUM FORMING)
ALGAE
FILAMENTOUS (MAT-FORMING) ALGAE
PLANT-LIKE MACROALGAE

4. • Different algae contain different pigments in them for attaining
sunlight, attaining energy through use of the sun rays.
• One of the common types is green algae.
• There is also blue-green algae, red algae, and even gold algae.
• So, there are many different types of algae and they can have many
different pigments.

5. GREEN ALGAE  Green algae contain primarily chlorophyll A and B.
 This reflects that green color.
 This makes them look either a bright or a dull green in
nature and these are all over the board.
 These can be very small, planktonic and microscopic
forms, or they can be thick large mats, and can even
include macro algae as well.

6. BLUE - GREEN ALGAE
 Also known as cyanobacteria.
 These contain the pigment phycocyanin, so this is a
blue-green pigment.
 They also have this other pigment that makes them
appear a darker green, sometimes even black in color
with this darker blue-green pigment

7. DI - ATOMS  They often appear goldish, gray, or yellow-
green in color.
 Because they have a pigment called
fucoxanthin.
 They look like little pieces of glass because
they have silica in their cell wall

8. IDENTIFICATION OF ALGAE BASED ON FEEL
• By feeling the algae, actually getting in there and grabbing it and smelling it.
Pithophora
• It’s a green filamentous alga.
• It almost looks like a cotton ball.
• This is also known as cotton algae
or horsehair algae.

9. Spirogyra
Spirogyra is more of a bright green
filamentous alga.
It’s more slick feeling.

10. Chara
 This is a type of macroalgae.
 It often grows up from the bottom of
the pond like a macrophyte or a land
plant.

11. Black filamentous
mats
 Lyngbya is a filamentous cyanobacterium, often dark in
color.
 It can grow way down in the sediments and appear almost
black in nature sometimes and smells bad, too.
 This produces some taste and odor compounds called
MIB and geosmin, making it smell dirty and fishy

12. Blue-green Algae
 These are actually cyanobacteria, are potential
toxin or taste and odor producers. not be able to
grab them, they often form this color or scums on
the surface.
 Some of the planktonic algae are extremely small,
and they require a microscope for correct
identification.

13. PREPARATION OF ALGAL SAMPLE
Collection
• Collect algal samples from their natural habitat or from
cultures.
Fixation
• Fix the algal cells using a fixative, such as formaldehyde or
glutaraldehyde, to preserve their structure.
Staining
• Stain the algal cells with a suitable stain, such as iodine or
methylene blue, to enhance their visibility.

14. MICROSCOPIC EXAMINATION OF ALGAL SAMPLE
• Mount the stained algal cells on a microscope slide using a mounting
medium, such as glycerin or water.
MOUNTING
• Observe the algal cells under a microscope, starting with low
magnification (40x-100x) and gradually increasing to higher
magnification (400x-1000x)
OBSERVATION
• Characterize the algal cells based on their morphology, including cell
shape, size, color, and arrangement.
CHARACTERIZATION

15. COMMON MICROSCOPIC FEATURES OF ALGAE
Green algae
(Chlorophyta)
Characterized by
the presence of
chlorophyll a
and b, and the
storage of starch.
Red algae
(Rhodophyta)
Characterized by
the presence of
chlorophyll a
and the storage
of floridean
starch.
Brown algae
(Phaeophyceae)
Characterized
by the presence
of chlorophyll
a and c, and
the storage of
laminarin.
Dinoflagellates
(Dinophyceae)
Characterized
by the presence
of chlorophyll
a and c, and
the storage of
starch.
Cyanobacteria
(Cyanophyta)
Characterized
by the presence
of chlorophyll
a and the
storage of
glycogen.