Microbio 3: Algae Protists

Flashcards on Algae: The Photosynthetic Protist

Algae Morphology

Unicellular, Colonial, Filamentous, clublike, spiral, or larger form (diverse morphology).

Algae

Protista that are photosynthetic autotrophs.

Algae Motility

Motility by flagella or gliding, may contain tiny light-sensitive areas (eye spots).

Algae Cell Walls

Algae have thick cell walls or thick cell membrane.

Major Phycocolloids

Alginates, Agars, Carrageenans.

Algae Distribution

Widespread inhabitants of fresh and marine waters including soil, rocks, and plants.

Plankton

Large floating community of microscopic organisms.

Algae Role

Play an essential role in the aquatic food web and produce most of the earth's oxygen.

Common Algal Groups

Green algae, red seaweeds, brown algae, diatoms, dinoflagellates, euglenids.

Green Algae

Large diversity in fresh water, one line very close to plants.

Chlorophyta

Phylum Chlorophyta, Most restricted to freshwater and terrestrial environments. 7000 species; 10% is marine; many are unicellular.

Spirogyra

Filamentous alga, often producing long green strands in pond water.

Red Algae (Phylum Rhodophyta)

Red pigments; phycobilins mask chlorophyll. Largest group of seaweeds, about 4000 species; most exclusively marine.

Coralline Red Algae

Smooth or rough encrusting growth on rocks. Warm-water coralline red algae actively involve in formation coral reefs.

Carrageenan

Used for stabilizing chocolate, milk, egg nog, ice cream, sherbets, instant puddings, frostings, creamed soups, etc.

Agar (or agar-agar)

is used in bacteriology and mycology as a stiffening agent in growth media. is used as a stabilizer for emulsions, and as a constituent of cosmetic skin preparations, ointments, and lotions.

Brown Algae

Phylum Heterokontophyta, Class Phaeophyta (Phaeophyta). Fucoxanthin dominate over chlorophyll, primary producers on temperate and polar rocky coasts

Kelps

Found in deeper water below the lowest tide level. They form kelp beds or kelp forest. Can grow at least 50 cm per day in optimal condition, reaches 100 m

Algin

Anionic polysaccharide distributed widely in the cell walls of brown algae used as thickening agent in ice cream, toothpaste, shaving creams, hair sprays, and lotion.

Golden Brown Algae (Phylum Chrysophyta)

'Chryso' means 'color of gold'. There are three types of golden-algae: yellow-green algae, golden brown algae, diatoms.

Diatoms

Diatoms are the most abundant and are found in seawater and freshwater habitats. The shell of diatoms are made of silica.

Dinoflagellates - Fire Algae

Phylum Pyrrophyta (Fire Algae), Dinoflaggelate means 'spinning swimmers'.

Red Tide

Common cause of red tides - algal blooms. Gonyaulax, which contain a neurotoxin and are poisonous to marine fauna.

Harmful Algal Blooms (HABS)

Occur in coastal areas where terrestial runoff of nutrients causes the growth and proliferation of sometimes monospecific blooms of toxic algae.

Algae that produce toxins

Algae that produce toxins: Dinoflagellates, Diatoms, and Cyanobacteria (cyanobacteria).

Toxic dinoflagellate blooms

Toxic dinoflagellate blooms, Ciguatera Fish Poisoning, Diarrhetic Shellfish Poisoning, Neurotoxic Shellfish Poisoning, Paralytic Shellfish Poisoning

Algae associated with Brown tides

Aureococcus, Aureoumbra

Ciguatera Fish Poisoning

Gambierdiscus toxicus (a dinoflagellate). Associated with weeds and coral reefs

Diarrhetic Shellfish Poisoning

Dinophysis acuminata, Dinophysis fortii, Prorocentrum lima
Okadaic acids and dinophysistoxins

Neurotoxic Shellfish Poisoning

Karenia brevis (previously Gymnodinium breve)
Florida, Gulf of Mexico
Brevetoxins

Paralytic Shellfish Poisoning

Alexandrium spp.
Gymnodinium spp.
Pyrodinium spp.
Northern Atlantic and Pacific coasts
Temperate and tropical
Saxitoxins

Amnesic Shellfish Poisoning

Pseudo-nitzschia spp. (diatoms)
Domoic acid and Glutamic acid

EUGLENIDS (EUGLENOPHYTA)

Unicellular organisms with flagella. Possesses features of algae and protozoa.

Protozoan feature of Euglenids

Presence of primitive mouth (cytosome) and the absence of cell wall structured with a thick outer covering, known as a pellicle, that is composed of protein and gives them both strength and flexibility.

Protothecosis, otherwise known as Algaemia

A disease found in dogs, cats, cattle, and humans caused by a type of green alga known as Prototheca that lacks chlorophyll and enters the human or animal bloodstream.