What are algae

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What are algae?

• Pond scums, seaweeds, freshwater and marine
  phytoplankton etc.
• Similarities to plants
• Root-like, stem-like, leaf-like structures
• small, single-celled forms to complex
  multi-cellular forms
• primary producers the base of the food chain
• Photosynthesis release oxygen
• Alternation of generations life cycle

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Where are algae found?

• most habitats, ranging from marine and freshwater
  to desert sands and from hot boiling springs to
  snow and ice

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Algae slide show

• http//www.botany.uwc.ac.za/presents/algae1/algaeb
  ase.html

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Harmful blooms

• Pfiesteria hysteria
• dinoflaggelate
• Cause of major fish kills in 1990s
• North Carolina coast
• Chesapeake Bay
• Cells from Hell digital video
  http//rave.ohiolink.edu/dmc/video/2793659

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life cycle of Pfiesteria piscicida
lesions from Pfiesteria
cyst
amoeboid
flagellate
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Caulerpa taxifoliaGreen Menace

• Green alga constructed like a green garden hose
  through which runs a continuous stream of
  cytoplasm
• Invasive species that out-competes native algae,
  corals and sea fans
• Small fragments can easily disperse colonize
  new areas

NOVA News Minute, http//www.pbs.org/wgbh/nova/alg
ae/
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Microcystis aeruginosa

• Cyanobacteria (blue-green algae)
• floats and forms a surface scum, sometimes
  appearing like blue-green paint floating or
  billowing near the surface
• Produces toxin, ingestion of water containing
  high concentrations can cause
• abdominal stress in humans
• Beach closures
• kill dogs and farm animals

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Microcystis bloom at mouth of Maumee River, Lake
Erie
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Algae Friend or Foe?

• scum (algal blooms), mass mortality of other
  organisms
• . Any good uses?

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Algae as the entree
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Uses of Seaweed
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What are seaweeds?

• Seaweeds are algae that live in the sea or in
  brackish water.
• red (6000 species)
• brown (2000 species)
• green (1200 species)

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Seaweed as Human Food

• staple item of diet in Japan China
• 21 species in everyday cookery in Japan, 6 of
  them since the 8th century
• 10 of Japanese diet
• seaweed consumption averaged 3.5 kg per household
  in 1973

Kombu (Laminaria species) http//seaweed.ucg.ie/d
efaulttuesday.html
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Alginic Acid (Alginate)

• colloidal product used for thickening,
  suspending, stabilizing, emulsifying,
  gel-forming, or film-forming, as required.
• Half used in ice cream and other dairy products
• Rest in other products
• shaving cream, rubber, or paint
• Textiles thicken fiber-reactive dye pastes, to
  increase sharpness in printed lines and conserves
  dyes
• dental impressions of teeth

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Food (dairy)

• Whipped toppings
• Cheeses
• Instant breakfasts

• Milk shakes
• Flans custards
• Ice cream

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FOOD (Nondairy)

• Frozen foods
• Syrups
• Relishes
• Meringues
• Dessert gels
• Fruit juices
• Sauces and gravies
• Salad dressings

• Pastry fillings
• Bakery icings
• Cooked/instant puddings
• Chiffons
• Candies
• Jams jellies
• Pimiento strips

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Medicinal Uses of Red Algae (Rhodophycota)

• Digenea produces an effective vermifuge (kainic
  acid)
• obstetrics to dilate the cervix and were known as
  "Laminaria tents
• dry stipe slowly takes up water and expands
• used in China for the insertion of intrauterine
  devices.
• Dumontiaceae aqueous extracts inhibit herpes
  simplex virus but no tests have been carried out
  on humans.
• Ptilota produces a protein (a lectin) which
  preferentially agglutinates human B-type
  erythrocytes in vitro.

• Corallina used in bone-replacement therapy.

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Seaweed industrial gums

• Hydrocolloids
• Polysaccharides used as emulsifiers, stabilizers
  gelling gums
• used to achieve various levels of viscosity
• alginates (alginic acid)
• Brown algae
• Agars
• Red algae
• Carrageenans
• red algae

• Artificial products dont have exact gelling
  viscosity properties of seaweed gums

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Alginic acid(brown algae)

• stabilizers in ice cream, giving a smooth texture
  and body
• suspending agent in milk shakes
• thickening paste for colors in printing textiles
• hardener and thickener for joining threads in
  weaving
• pharmaceutical preparations
• glazing and sizing paper
• special printers' inks, paints
• Cosmetics
• Insecticides

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Agar

• from red algae
• Gelling agent
• solid microbiological culture substrate
• used in various kinds of ices, canned foods and
  bakery products

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Carrageenans

• similar to agar, but requires higher
  concentrations to form gels
• used for stabilizing chocolate, milk, eggnog, ice
  cream, sherbets, instant puddings, frostings,
  creamed soups, cottage cheese, lotions, paints,
  toothpaste, etc.

• Most Chondrus comes from the Maritime Provinces
  of Canada (Nova Scotia etc.)

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Production and value of international seaweed
gums market, 1995
(Quest International, Cork IMR International,
San Diego)
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Fertilizer / soil amendments

• "lazy beds Soil or sand is layered with seaweed
  for vegetable production, particularly potatoes
• decomposes very slowly
• soils of poor water-retention qualities, seaweed
  may be very useful as it retains water very well,
  but there may be problems with the high salt
  content
• A tradition for Breton farmers transport large
  quantities of the brown alga Himanthalia elongata
  from the sea for artichoke crops
• fertilizers and soil stabilizers for seeding
  motorway embankments in Britain

Dunguaire Castle, near Kinvarra, Co. Clare,
Ireland. This Norman edifice is almost surrounded
by the sea the lines in the foreground are of
dift seaweed.
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crustose, calcareous red algae (Corallinaceae)

• grows detached in shallow waters on the coasts of
  NW Europe and in the western Mediterranean
• Organic farmers horticulturists use for trace
  elements
• Rich in calcium magnesium carbonates
• Good for water filtration.

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Liquid extracts of marine brown algae

• Dried meal prepared from hot-water extracts of
  either dried or wet
• maxicrop
• Benefits
• increased yields
• increased uptake of inorganic constituents from
  soil
• more resistance to stress, including frost

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Diatomaceous earth

• unicellular organisms
• primary sources of food for zooplankton in marine
  freshwater
• Economic uses
• Filters
• Rubbing compounds (polish)
• Pest control (fleas)

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Foraminifera
Uvigerina
Dorothia
Astacolus
Pleurostomella
Discorbis
Planulina
Endothyra