5th lecture envi engg (algae)

Algae

-Protista that are photosynthetic autotrophs

-wide spread inhabitants of fresh and marine water

Polyphyletic

Group of organism derive from more than one ansester

Flagella

Motility of algae

stigma

Algae tiny light sensitive areas (eyes spot)

Pellicle

Algae have thick cell wall or thick cell membrane called

Alginates, agars, carrageenas

3 major phycocolloids

Phycocolloids

Cell wall of many seaweeds contain

Plankton

Large floating community of microscopic organism

Chlorophyta

Green algae

Rhodophyta

Red seaweeds

Phaeophyta

Brown algae

Chrysophyta

Diatoms

Phyrrophyta

Dinoflagellates

Euglenophyta

Euglenids

Green algae

-large diversity in fresh water

-present in marine habitats but not as important as reds and browns

Spirogyra

Filamentous algal, often producing long green strands in pond water

Conjugation

Spirogyra reproduce through

Red algae

-A largest group of seaweeds about 4000 species most exclusively marine

-found in most shallow water marine environment

Phycobilins mask chlorophyll

Red pigment

Coralline red algae

-Smooth or rough encrusting growth on rocks

-actively involve in formation of coral reefs

Carrageenan

-Is used for stabilizing chocolate milk egg nog ice cream sherbets instant pudding frosting creamed soups etc

- is similar to agar, but requires higher concentration to for. Gels

Gigartina stella, chondrus crispus and eucheuma

Carrageenan is made from

Agar

Is used in bacteriology and mycology as a stiffening agent in growth media

Karenia brevis

Neurotoxic shellfish poisoning

Gledium,gracilaria,pterocladia and Ahnfeltia

Agar is made from

Chlorophyll pigment

Green pigment

Brown algae

Largest and most complex seaweeds

Phylum heterokontophyta

Class phacophyta (phaeophyta)

Fucoxanthin dominate

Brown pigment

Kelp

-found in deeper water below the lowest tide level

-can grow atleast 50 cm per day in optiml condition reaches 100m

-among the richest, most productive environment in marine realm

Giant Kelp

Is a good source of algin

Giant Kelp

Macrocystis pyrifera

Algin

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

Chryso

Means color of gold

Yellow green algae, golden brown algae, diatom

3 types of golden algae

Diatom

-Are the most abundant and are found in seawater and fresh water habitats

-they are major source of food to may aquatic organisms

Silica

The shell of diatoms are made of

diatomaceous earth

a soft, fine, porous deposit that is composed mainly of the skeletons of diatoms

Dinoflagellates

-Fire algae

-spinning swimmers

-commong cause of red tide

Gonyaulax

The dinoflagellates causing red tides are known as

Redtide

Caused by dinoflagellates and diatoms

Dinoflagellates, diatoms and cyanobacteria

Algae that produce toxins

Ciguatera fish poisoning, diarrhetic shellfish poisoning, neurotoxic shellfish poisoning, paralytic shellfish poisoning

Toxic dinoflagellate blooms

Amnesic shellfish poisoning

Toxic diatom bloom

Gambierdiscus toxicus

Ciguatera fish poisoning

Ciguatoxin and maitotoxin

Ciguatera fish poisoning toxin

Sodium

Ciguatoxin

Calcium

Maitotoxin

Dinophysis acuminata, dinophysis fortii, prorocentrum lima

Diarrhetic shellfish poisoning

Okadaic acids

Diarrhetic shellfish poisoning toxin

Brevetoxins

Neurotoxic shellfish poisoning toxin

Alexandrium spp, gymnodinium spp, pyrodinium spp

Paralytic shellfish poisoning

Saxitoxin

Paralytic shellfish poisoning toxin

Pseudo-nitzschia spp.

Amnesic shellfish poisoning

Domoic acid

Amnesic shellfish poisoning

Euglenids

-Possesses features of algae and protozoa

-they do not have a cell wall instead they have thick outercovering known as pellicle that is composed of protein and gives them both strenght and flexibility

Stigma

Euglena also have eyespot at the anterior that detects light

Anatoxins

Cyanobacterial neurotoxins

Microcystin, nodularin

Cyanobacterial hepatotoxins

Lyngbyatoxin, aplysiatoxin

Dermatitis