2. Algae
• Unicellular
• Ubiquitous many live in aquatic water but many therive river terrestrial and
subterranean algea.
• photosynthetic
• Single algea are complete organism capable of photosynthesis and synthesis
multitude of other components.
3. • Algea are heterogeneous group.
• They range from microscopic unicellular size to bacteria to seaweeds that
may grow to many feet in length.
• Study of algea is known as phycology.
4. Occurrence of algea
• Many thousands occur in nature.
• They occur in abundance in oceans sea salt lakes freshwater lakes pounds and
streams.
• Small aquatic form make a large part of free floating microscopic plankton in water.
Plankton are considered to be made of both algea and microscopic animal form.
• Phytoplanton is made of plant algal form.
• Zooplankton is made of animal form.
5. • Some algea grow on snow and ice some on landscapes become colored by
red pigment.
• At other extreme some algea grow in hot springs at 55°C.
• Some freshwater algea adopted their metabolism to high salt concentration.
• Marine algea adapted to variation in salt concentration.
• Other adjusted to air and drying.
6. • Marine algea found at depth of 150 180 ft in in northern water.
• In clear tropical water where sunlight is direct they grow at depth of 600ft.
• These and other factors responsible for zoonation process.
7. The biological and economic importance
of algea
• When dispersed in natural water algea increase oxygen concentration through
photosynthesis.
• Heavy growth of some algea reduce hardness of water and remove salt that
cause brackishness of water.
• Phytoplanton serve as important food for organisms in sea.
• Algea form base of food chain because of their primary photosynthetic
activities therefore called primary producers.
8. • Algea are also present in soil even if there presence are not so obvious.
• They are important in stablizing and improving physical condition of soil by
aggregating particals and adding organic matter.
• In many countries red and brown seeweeds are plentiful they are used as
fertilizer.
9. • Agar alginic acid and carrageenan are extracted from algal cell wall.
• Filamentomaceous earth is composed of million upon million of diatoms glass
walls deposited over time in either freshwater or ocean.
• Agar and carrageenan are polymer of glactose and glactose caintaing compounds
with sulphate groups.
• Some of sulphate groups re involved in bonds between individual suger residue.
• Agar and carrageenan both called sulfated glactans.
• Algenic acid consists of ironic acid residues all three compounds are either used in
making gels or viscous solutions.
10. Carrageenan
• Extracted from wall wall of several red algea Chondrus Gigartina Eucheuma.
• Used as stablizer or emulsifier in foods such as ice cream and other milk
products.
• As agent in ulcer therapy.
• As finishing compound in textile paper industry.
• As thickining agent in shaving cream and lotions and in soap industry.
11. Agar
• Solidifying agent in preparation of microbial culture media.
• Obtain from red algea Gelidium Gracilaria.
• In food industry in making cheese mayonnaise puddings jellies baking
products and canned goods.
• In pharmaceutical industry used as carrier for drugs.
• Lotions and ointments caintains agar.
12. Alginic acid
• From wall of brown algea Macrocystis Agarum Laminaria Fualginates
Ascophylum.
• About 50 percent of ice cream in U. S caintains alginates that prevent ice
crystals formation and provide smooth consistency.
• Incoperated into cheese and bakery products especially frosting.
• Used in paper manufacturing printing of fabric and paint thickining.
• Used by dentist for making impression of teath for crowns.
13. Algenates
• The stem like part of brown algea may be used by physicians for cervical
dialation or softening of cervix for performing abortion or placing radium
implant.
• Stipe is cut into sections dried and sterilized by ethylene gas.
14. Diatomaceous earth
• Primarily for filters or filter aids.
• It is not chemically reactive and can be compressed during use.
• It is available in many grades.
• For polishing delicate surfaces.
• Most important red algea porphyra it is used as food in japan where it is
called nori and it is proceede to dry sheet.
15. Nori
• Nori is commonly toasted over flame and sprinkled in soup or rice it is rolled
around flavored Rice with fish or vegetables to make popular luncheon snack
called sushi.
• Other red algae such as chondrus Acanthopeltis Nemalian and Eucheuma
most of them are eaten as vegetables or in soups or as sweetend jellies.
• Red algae Continue to be significant food in China such algae have been
food staple or delicacy in China.
16. • In contrast to diversity is specie eaten by Asian and polynesian people red
algea food usage in Europe and North America have centered around three
genera
• Porphyra or laver
• Chondrus or Irish moss
• Palmaria or dulse
17. • Laver used extensively in British Isles.
• About 50 tons of dried dulse are produced each year in Canada.
• Algae is collected in Bey of Fundy and on shores of Nova Scotta.
• Dulsa is commonly eaten as snack in taverns.
18. Chlorella
• As food for humans and domestic animals they provide rich source of
proteins comprising all amino acid essential for growth.
• They are also good source of carbohydrates and fats.
• Methods for mass cultivation of these plants using waste products and
sewage for their nutrition have been developed.
19. Algae and disease
• Although few algae are pathogenic.
• Prototheca colourless cholera like animal superficially resemble yeast is
pathogenic to human and found in bursitis an inflammation of joints.
• Cephaleuros attack leaves of tea coffee pepper causing considerable damage.
• Some algae live in roots and fleshy parts of higher plants liverwoots
duckweeds and other host such algae don’t harmed by their presence.
20. Extracellular inhibitors produced by algae
• Acrylic acid produced by unicellular algae in plankton.
• Some algae produced toxin that are lethal to fish and other animals.
• These liberated from algae by bacterial decomposition of water blooms.
• Gymnodinium and Gonyaulax cause death of aquatic animals by producing
higher molecular weight toxins.
21. • Shellfish poisoning occur along northeastern coast of America as well in
North Pacific.
• Gonyauiax catenella on West Coast.
• Gonyaulax excavata on east coast.
• Blooms of these lasts for few weeks and often it is safe to eat shellfish after 2
weeks.
22. • Poisonining in humans came from eating filter feeders clams scallops mussels
which filter plankton from sea water.
• After ingesting toxin victim first experience a numbing on lips tongue
fingerstips usually after 30 minutes of eating shellfish.
• Diaphram soon affected and in serious case respiratory failure can result.
23. Characteristics of algae
• Algae have wide range of shapes and size.
• Many occur as single cell that may be spherical rod shaped club shaped
spindle shaped.
• Other are multicellular and appear in conceivable form shape and degree of
complexity including membranous colonies filaments group or in clusterwith
individual strand that may be branched or unbranched and tubes.
24. • Some colonies are simple aggregation of single identical cell that cling
together.
• These colonies become complex resembles higher plants.
• Algal cell are eukaryotic.
• Cell wall is rigid and thin.
• Cell wall of diatoms are impregnated with silica making them thick and rigid.
25. • Motile algae such as Euglena have flexible cell membrane called periplasts.
• Cell wall of many algae is surrounded by flexible gelatinous outer matrix
secteted through cell wall reminiscent of bacterial capsule.
• As cell grow outer matrix become stratified and pigmented.
• Algae caintains discrete nucleus.
26. • Other inclusions includes starch grain oil droplets and vacuoles.
• Chlorophyll and other pigments are found in membrane bounded organelle
known as chloroplasts.
• Within plastids matrix and stroma are found flattend membranous vesicles
called thylakoid.
27. Algal pigments
• Several divisions of algal caintains colorless mebranes.
• There are three kind of photosynthetic pigments in algae.
• Chlorophyll
• Caretenoids
• Biloproteins
28. Chlorophyll
• There are five chlorophylls a b c d e.
• Chlorophyll a is present in all photosynthetic organisms other than
anoxigeneic bacteria.
• Chlorophyll b is found in Euglenophycophta and chlorophycophyta and no
other algal division.
• Chlorophyll c is most widespread and found in xanthophycophyta
bacillariophycophyta chryophyvophyta pyrophycophyta cryptophycophyta
paeophycophyta.
29. • Chlorophyll d present only inRhodophycophyta.
• Chlorophyll e found in Xanthophycophyta two genera namily Tribonears and
zoospore of Vaucheria.
• Carotenoids are of two kinds :-
• Carotenes
• Xanthophyll
30. • Carotenes are linear unsaturated hydrocarbons.
• Xanthophyll are oxygenated derivatives of theses.
• Billoproteins are water soluble whereas chlorophyll and carotenoids are
lipid soluble.
• Phycobilins are pigments proteins complexes are present in only two algal
divisions.
• Rhodophycophta and cryptophycophyta.
31. Motility and reproduction
• Motile algae are called swimming algae have flagella occur in singlet or pairs or in
clusters at anterior or posterior end.
• variations in taxonomic significance has been found in algal flagella.
• Whiplash cylinder and smooth
• Tincel cylindrical with hair like appendages.
• Ribbon or straplike
• Some algae have no mean of locomtion and carried about by tides water currents
32. • Small red or orange body is present the eyespot present near anterior end of
motile algae
• Other structures includes
• Spines or knobs on exterior.
• Gelatinous stalk by which algae anchor to object.
33. Reproduction
• Algal may reproduce sexually or asexually.
• Asexual reproduction process include vegetative type of cell division.
• New filament or algal colony starts from fragment of old multicellular type
from which it broke.
• Many aquatic for produce asexuall spores that are motile have flagella called
as Zoospore. Non motile are aplanospore however some aplanospore
convert into Zoospore.
34. species of yellow-green alga
called Vaucheria sessilis is an example of a
sexually reproducing alga. The
reproductive structures consist of an
antheridium, which contains male
gametes, and two oogonia, which contain
female gametes.
35. giant kelpThe giant kelp
species Macrocystis pyrifera reproduces
sexually and has distinct haploid and
diploid stages. The reproductive behaviour
of M. pyrifera is heavily influenced by
water temperature and the availability of
nutrients.
36. Algae in the genus Bambusina, a group of
freshwater desmids in the division
Chlorophyta (green algae), are capable of
forming zygospores and therefore entering
a state of dormancy.
37. • All form of sexual reproduction found in algae.
• In this process there is conjugation of sex cells gametes to form union.
• Blending of genetic material occur.
• Union of gametes form zygote.
• If there is no visible sex differentiation then fusion process is isogamous.
• If gametes are unlike differ in size process is hetrogamous.
38. • In higher cell sex cell become more characteristically male and female.
• Ovum is large and non motile.
• Sperm is small and motile.
• This type of sexual reproduction is oogamy.
• Male and female thalli also exist both look alike but are of opposite sex types.
• One produce male gamete other produce ova. Such plants or diocious or uni sexual.
39. Lichens
• Composite organisms consists of algae or cyanobacteria living is association
with fungi.
• They group on rocks tree bark and other substrates suitable for growth of
other plants.
• Many are able to grow on low temperature at high altitudes and in polar
environment. e. g Reindeer Moses.
• Colony of lichens range from white to black through shades of red orange
yellow green.
40. Morphology
• Simple lichens made of top layer of tightly wooven fungal mycelia bellow are
photosynthetic cell below that another layer of fungus.
• Bottom layer attach to substarate directly by mean of short twisted strand of
hyphae called rhizines.
• In some algae mid layer of fungus directly below the algae apera to be
reservoir of food.
• Not all species of fungal not of algal for lichenline relationship.
41.
42. • Most lichen fungi are Ascomycetes few are basidiomycetes.
• Algae belong to division cholorophycophta.
• About 30 general of algae and cyanobactetia found in lichen most common
is unicellular green algae Trenouxia Trentipohlia and Boston.
• All the morphological character used in classification of lichen are fungal
characters and it is acceptable to speak lichenized fugus.
43. Types of lichen
• There are three types of lichen:-
• Crustose are flat appresed
• Foliose leaflike
• Fructose shrublike
• Crustose grow closely appresed to substrate rock wood.
• Foliose are flattened like leaves but may not connected to substrate at all points
• Fruticose have erect shrub like or filaentous morphology and can be 10 cm long.
44.
45. Reproduction
• Asexuall:-
• Lichenpredominantly reproduce by vegetative process.
• Propagation by fragmentation occur when of bit of thallus broke from
parent plant and fall on Suitable substrate.
• Lichen produce asexual bodies soredia which are knots of hyphae caintaining
few algal cells.
46.
47. • Sexual reproduction:-
• During sexual reproduction components of lichen reproduce independently.
• Fungal component produce ascospore when they germinate they come in
contact with algal cells or they will not be able to survive.
• Algal partner reproduce by cell division or occasionally by spores.
48.
49. Lichens
• Lichen grow slowly because of low metabolism.
• Many species grow less then a centimeter per year.
• Some lichen have therefore reached great age in nature for example 45,000
years of some species in Arctic regions they are very resistant to heat and
desication.
51. Morphology of lichens
• Lichen are product of mutualistic symbiosis.
• Algal or cyanobactetia provide fungus with food like carbohydrates and
vitamins.
• Fungus absorb stores and supplies water and minerals required for algal or
cyanobactetia as well provide carbon dioxide moist shelter supporting
framework for photosynthetic partner.
• Fungus obtain nourishment by mean of root like projections called
Haustoria which penetrates photosynthetic cell.
52. Chemical interaction
• Unusual fats and phenolic compounds make up 2 to 20 percent of dry
weight of algae.
• Litmus is well known pigment indicator is obtained from lichen.
• Esential oils from some species are used in perfumes.
• Lichen pigment are used in England to color woolen fabrics of Harris
Tweed.
