1.
Algae
Procaryotic, eucaryotic, photosynthetic micro and
macro organism
Unicellular, microscopic and macroscopic

2.
Algae

3.
Sea weeds

4.
Biological and Economic importance of
Algae
1. Primary produce-
• most are aquatic
• Floating phytoplankton- food for aquatic life
2. Commercial products-
a. agar- well known solidifying agent used in
microbiology laboratory
• Obtained from red algae (marine)-Geledium and
Gracilaria
• Used in food industries for making pudding,
processed cheese, mayonnaise, jellies

5.
Biological and Economic importance
of Algae
• Used as a carrier for drug in pharmaceutical
industry
• Lotion and creams also contain agar
b. Alginic acid and its salt obtained fron brown algae,
eg. Macrocystis, Agarum
• Alginates- added in ice creams for smooth
consistency
• Also in cheese and bakery products
• Paper manufacturing
• Printing of fabrics, paint thickening

6.
Biological and Economic importance of
Algae
c. Carrageenan- polymer of galactose with sulfate
group
Extracted from red algae- Chondrus
Used as a stabiliser or emulsifier in icecream and
other milk products
Used as a thickening agent in shaving creams, lotion
and in the soap
Useful in textile and paper industries
d. Diatomaceous earth- composed of millions of
diatoms

7.
Biological and Economic importance of
Algae
• Used in filters, non reactive chemically
• Finely divided- one gram is having 120sq mt
surface area
• Also used for polishing delicate surface area
3. Algae as food- Porphyra used in Japan(called nori
served with fish)
(red algae)

8.
Chondrus

9.
Palmeta

10.
Gracilaria-red algae (china)

11.
Chlorella

12.
Advantages of algal food
• Rich source of proteins with all amino acids
essential for growth
• Good source of carbohydrate and fats as well
• Can be grown on waste materials

13.
Algae and diseases
• Prototheca-1.human skin infection
• 2. bursitis- joint pain

14.
Cephaleuros- plant pathogen

15.
Characteristics of Algae
• Morphology- wide range
• Spherical, rod shaped, club shaped, spindle
shaped(single celled sp)
• Multicellular – complex, group of same cells or
different cells (may resemble higher plants)
• Cell wall- thin and rigid.
• Diatoms have silica and therefore thick and very
rigid.
• The motile algae have flexible cm called periplast
• Some have an outer matrix secreted through cw

16.
Unicellular algae

17.
Algal pigments
• Chlorophyll-a,b,c,d,e,
• a is present in all

18.
Carotenoid
• Carotene- unsaturated hydrocarbon
• Xanthophyll- oxygenated derivative

19.
Biloprotein (phycobilin)
• Water soluble pigment- phycocyanin and
phycoerythrin

20.
Motility
• Motile algae- swimming algae
• Flagella-in pairs, clusters
• Types- whiplash (cylindrical and smooth), tinsel
(cylindrical and hair like), ribbon or strap like
• Some don’t have means of motility
• Carried about by currents, tides, waves
• Some spores are motile- zoospore
• Other structures- eye spot, knob like structure,
gelatinous stalk

21.
classification
• Based on-
• Nature and properties of pigments
• Chemistry of reserve food material
• Types or number of flagella, morphology and
insertion
• Life history, reproductive structures, and methods
of reproduction
• Eg. Geledium
• Very useful commercially

22.
Rhodophycophyta
• Chlorophyll a, b and phycoerythrin
• Cell wall- cellulose
• Reserve food- starch
• Red algae
• Marine forms
• Asexual reproduction- non motile spore
• Sexual reproduction- heterogamous
• (spermatia and carpogonia)

23.
Xanthophycophyta(yellow-green
algae)

24.
• Chlorophyll a, c rarely e
• Found in temperate environment(fresh water and
marine), also in soil
• Occur as single cell, colonies, branched and
unbranched filaments
• Flagella of unequal length
• Zoospores
• Asexual reproduction by cell division and
fragmentation
• Sexual reproduction rare
• Cell wall- cellulose, pectin
• Reserve food material- chrysolaminarin(branched
glucan), oil
• Eg Vaucheria

25.
Chrysophycophyta- golden algae
• Chlorophyll a and c
• Beta carotene and fucoxanthin
• Predominantly flagellate
• Some have pseudopodia
• Some are non-motile
• Most forms are unicellular and form colonies
• Reserve food material- chrysolaminarin(branched
glucan), oil
• Eg. Ochromonas

26.
Phaeophycophyta- brown algae
• Chlorophyll a and c
• Multicellular, brown pigment
• Found in marine environment
• Quite complex(some have several feet height)
• Eg brown sea weed
• Have holdfast and air bladder (give buoyancy)
• Asexual reproduction- zoospore
• Sexual reproduction- isogamous and heterogamous
• Commercial uses-food, source of iodine and mineral
salt
• Eg. Sargasso

27.
Sea of Sargasso

28.
Bacillariophycophyta-the Diatoms
• Chlorophyll a and c
• Found in fresh water, salt water, soil
• Abundant in cold water
• Plentiful form of plankton in Arctic
• Wide range of shape
• Unicellular, colonial and filamentous forms
• Produce shell (CW) containing silica
• These shells over the period give rise to
diatomaceous earth, commercially very important

29.
Euglenophycophyta-euglenoid
• Chlorophyll a and b
• Unicellular, actively motile
• Interesting example is Euglena (animal as well as
plant features)
• Photosynthetic and contractile vacuole
• No cell wall, having periplast
• Anterior gullet and red eyespot
• Reproduction by binary fission
• Dormant cyst like structure is produced
• Paramylon, oils as reserve material

30.
Chlorophycophyta- green algae
• Chlorophyll a and b
• Freshwater
• Some in marine and terrestrial environment
• One chloroplast per cell, laminate, cup shaped and
reticulate
• Chloroplast has pyrenoid- a site of starch synthesis
• Single celled and colonial forms
• Some has holdfast for attachment
• Produce zoospore
• Binary fission and isogamous, heterogamous
reproduction

31.
chlamydomonas

32.
spirogyra

33.
volvox

34.
Cryptophycophyta
• Chlorophyll a and c
• Biflagellate organisms, two unequal flagella, tinsel
type
• Cells slipper shaped
• Some have only plasmalemma
• One or two plastids with or without pyrenoid
• Reproduction by binary fission, zoospore and cyst
• Sexual reproduction is seen in some

35.
Cryptomonas

36.
Pyrrophycophyta- the Dinoflagellate
• Chlorophyll a and c
• Plant and animal like features
• Flagella are in girdle, one flagellum is encircling
and one trailing
• Plasmalemma and some have cellulose plates in
plasmalemma (thecal plate)
• Can produce red pigment, Gonyaulax (red tide)
• Simple cell division and occasionally sexual
reproduction

37.
group chlorophyll carotenoid biloprotein Storage products
Rhodophycophyta
Red algae
a, rarely d Beta carotene
Zea xanthin
Alpha carotene
Phycoerythrin
phycocyanin
Starch, oil
Xanthophycophyta
Yellow- green algae
a, c, rarely
e
Beta carotene
Diadinoxanthin
Heteroxanthin
Chrysolaminarin,
oils
Chrysophycophyta
Golden algae
a, c Beta carotene
fucoxanthin
Chrysolaminarin,
oils
Phaeophycophyta
Brown algae
a,c Beta carotene
Alpha carotene
fucoxanthin
laminarin, oils,
carbohydrate
Bacillariophycophyta
Diatoms
a, c Beta carotene
Alpha carotene
fucoxanthin
Chrysolaminarin,
oils
Euglenophycophyta
Euglenoid
a, b Beta carotene
Alpha carotene
Diadinoxanthin
Paramylon, oils

38.
group chlorophyll carotenoid biloprotein Storage
products
chlorophycophyta
Green algae
a, b Beta
carotene
Alpha
carotene
lycopene
Starch, oil
Cryptophycophyta
Cryptomonad
a,c Beta
carotene
Alpha
carotene
alloxanthin
Phycoerythrin
phycocyanin
Starch, oil
Pyrrophycophyta
dinoflagellate
a,c Beta
carotene
Alpha
carotene
Peridenin
Starch, oil