Introduction__to_Algae_Detailed.pptx.pdf

Introduction of microalgae in detailed explanation

1. A: VIVEKANANDA ARTS AND SCIENCE
COLLEGE FOR WOMEN

Veerachipalayam 637 303 Sangakiri, Salem dt, Tamilnadu

DEPARTMENT OF MICROBIOLOGY

Subject: MICROALGAL TECHNOLOGY
Topic: INTRODUCTION TO ALGAE

Subject incharge.

DR. R. Dinesh Kumar
Assistant professor
Department of Microbiology,
Viaas, Sankagiri.

Submitted by
S. Abinisha
I-MSC(Microbiology)
Department of Microbiology,
Viaas, sankari.

2. Introduction to Algae

«+ Algae are a large and diverse group of
organisms, mainly aquatic, capable of
photosynthesis. Unlike higher plants, they
lack true roots, stems, and leaves but play a
crucial role in ecosystems and human life.

3. What are Algae?

» Algae are simple, autotrophic organisms
that can be unicellular or multicellular.
They contain chlorophyll and perform
photosynthesis, producing a significant
portion of the world's oxygen. They are
found in oceans, rivers, lakes, moist soils,

and even extreme environments. a

4. Historical Background

» The term 'algae' originates from the Latin
word for seaweed. Early naturalists studied
algae for their diversity and ecological role.
Anton van Leeuwenhoek first observed
microscopic algae, and later, classification
systems expanded with discoveries of green,
red, and brown algae.

5. Habitat and Distribution

« Algae inhabit a wide range of environments.
Most are aquatic, thriving in freshwater,
marine, and brackish waters. Some live in
moist soils, tree trunks, snow, and rocks.
Extremophilic algae adapt to hot springs,
deserts, and polar regions.

6. Basic Structure

» Algae exhibit a thallus organization, lacking
true roots, stems, and leaves. Their body
can range from unicellular (Chlorella) to
colonial (Volvox) to large multicellular
forms like seaweeds (Laminaria).

paramylon body
nucleus
chloroplast

pellicle

Euglena Structure

7. Cell Structure
« Algal cells are eukaryotic (except
cyanobacteria) and contain organelles such
as chloroplasts for photosynthesis,
mitochondria for energy, and a rigid cell
wall made of cellulose, silica, or pectin.

8. Photosynthetic Pigments

« Algae contain pigments that absorb light
energy. Chlorophyll a is universal, while
other pigments vary: chlorophyll b in green
algae, phycobilins in red algae, and
fucoxanthin in brown algae. These pigments
allow them to thrive in different light
conditions.

9. Plant pigment

Photosynthetic
Pigments

Plant Pigments

Protective
Pigments

10. Types of Algae Overview

» Algae are a polyphyletic group, meaning
they do not come from a single ancestor.
They are broadly classified based On
pigments, storage products, and cell
structure into groups like green, red, brown
algae, diatoms, dinoflagellates, and
euglenoids.

11. Green Algae

« Green algae (Chlorophyta) contain
chlorophyll a and b, giving them a bright
green color. They store food as starch.
Examples: Chlamydomonas, Spirogyra,
Ulva. Many are freshwater, though some
are marine.

§ Caulerpa
racemosa

Green Algae
(Chlorophyta)

12. Red Algae

« Red algae (Rhodophyta) contain
chlorophyll a, d, and phycobilins, giving
them red color. Mostly marine, they thrive
in deep waters. Examples: Porphyra (used
in sushi), Gelid feces cores .

Red Algae
(Rhodoophyceae)

13. Brown Algae

« Brown algae (Phaeophyceae) are mostly
marine and multicellular, with a brown
color due to fucoxanthin pigment. They
are the largest algae, with kelps forming
underwater forests. Examples: Laminaria,
Fucus, Sargassum. gaze

Fucus
vesiculosus

Brown Algae
(Phaeophyceae)

14. Blue-Green Algae

eS eee "HA
¡+ Blue-Green algae, or cyanobacteria, are =
prokaryotes, unlike true algae. They perform

pe Oxygenic photosynthesis and can fix nitrogen.
re -Nostoc, Anabaena. ae 3

ful blooms in water bodies. — =*

15. Other Important Algal Groups

« Diatoms are unicellular algae with silica cell
walls, important in phytoplankton.
Dinoflagellates are marine plankton, some
bioluminescent, others cause red tides.
Euglenoids are mixotrophic, having both plant
and animal characteristics.

16. Reproduction in Algae

« Algae reproduce by vegetative
(fragmentation), asexual (spores, binary
fission), and sexual methods (isogamy,
anisogamy, oogamy). Reproductive strategies
vary among groups depending on complexity.

17. Life Cycles

« Algal life cycles range from simple haplontic
(dominant haploid stage) to diplontic
(dominant diploid stage) and haplodiplontic
(alternating haploid and diploid generations).
Examples include Spirogyra (haplontic) and
Laminaria (haplodiplontic).

19. Ecological Roles

« Algae produce about 50% of the Earth's
oxygen through photosynthesis. They are the
base of aquatic food chains, supporting fish
and marine life. They also form habitats like
kelp forests and coral reefs.

20. Algae and Photosynthesis

« Through photosynthesis, algae capture
carbon dioxide and release oxygen, playing a
vital role in the global carbon cycle.
Phytoplankton alone contribute significantly
to reducing greenhouse gases.

21. Economic Importance

« Algae are used as food (nori, spirulina), in
agar and carrageenan production, fertilizers,
biofuels, cosmetics, and pharmaceuticals.
Seaweed extracts are used in industries and
medicine.

22. Harmful Algal Blooms

« Excessive growth of algae, often due to
nutrient pollution, can cause harmful algal
blooms. These release toxins, cause fish kills,
and create dead zones. Examples: red tides
caused by dinoflagellates.

23. Algae in Biotechnology

« Algae are used in biotechnology for biofuel
production, wastewater treatment,
bioplastics, and carbon capture. Their fast
growth and high productivity make them a
sustainable resource.

24. Symbiotic Relationships

« Algae form mutualistic associations: with
fungi to form lichens, with corals to provide
nutrients, and with mollusks and other
organisms. These relationships support
ecosystems.

25. Adaptations

« Algae survive extreme conditions by
producing protective compounds, spores, and
specialized pigments. They adapt to high
salinity, temperature extremes, and low light
environments.

26. Future Applications

« Research focuses on algae as renewable
energy sources, nutritional supplements, and
climate change solutions. Algae could play a
major role in sustainable food and energy
systems.

27. Summary

« Algae are diverse, photosynthetic organisms
with ecological, economic, and
biotechnological importance. They support
life on Earth through oxygen production,
carbon fixation, and multiple applications.

28. References & Acknowledgments

« Books, research papers, and online resources
on phycology and microbiology were used to
prepare this presentation.