Environmental Engineering Reference
In-Depth Information
•
Chrysolaminarin
—The carbohydrate reserve in organisms of division
Chrysophyta.
•
Diatoms
—Photosynthetic, circular or oblong chrysophyte cells.
•
Dinolagellates
—Unicellular, photosynthetic protistan algae.
•
Dry mass factor
—The percentage of dry biomass in relation to the fresh
biomass; for example, if the dry mass factor is 5%, one would need 20 kg of
wet algae (algae in the media) to get 1 kg of dry algae cells.
•
Epitheca
—The larger part of the frustule (diatoms).
•
Euglenoids
—Contain chlorophylls
a
and
b
in their chloroplasts; represen-
tative genus is
Euglena
.
•
Fragmentation
—A type of asexual algal reproduction in which the thallus
breaks up and each fragmented part grows to form a new thallus.
•
Frustule
—The distinctive two-piece wall of silica in diatoms.
•
Hypotheca
—The small part of the frustule (diatoms).
•
Lipid content
—The percentage of oil in relation to the dry biomass needed
to get it; for example, if the algae lipid content is 40%, one would need
2.5 kg of dry algae to get 1 kg of oil.
•
Neustonic
—Algae that live at the water-atmosphere interface.
•
Oogonia
—Vegetative cells that function as female sexual structures in the
algal reproductive system.
•
Pellicle
—A
Euglena
structure that allows for turning and flexing of the cell.
•
Phytoplankton
—Made up of algae and small plants.
•
Plankton
—Free-loating, mostly microscopic aquatic organisms.
•
Planktonic
—Algae suspended in water as opposed to attached and living
on the bottom (benthic).
•
Protothecosis
—A disease in humans and animals caused by the green
algae,
Prototheca moriformis
.
•
Thallus
—The vegetative body of algae.
Algae are autotrophic, contain the green pigment chlorophyll, and are a form of
aquatic plant. Algae differ from bacteria and fungi in their ability to carry out pho-
tosynthesis—the biochemical process requiring sunlight, carbon dioxide, and raw
mineral nutrients. Photosynthesis takes place in the chloroplasts. The chloroplasts
are usually distinct and visible. They vary in size, shape, distribution, and numbers.
In some algal types, the chloroplast may occupy most of the cell space. They usu-
ally grow near the surface of water because light cannot penetrate very far through
water. Although when they are
en masse
(multicellular forms such as marine kelp)
the unaided eye easily sees them, many of them are microscopic. Algal cells may be
nonmotile or motile by one or more flagella, or they may exhibit gliding
motility
as
in diatoms. They occur most commonly in water (fresh and polluted water, as well as
in saltwater), in which they may be suspended (planktonic) or attached and living on
the bottom (benthic); a few algae live at the water-atmosphere interface (neustonic).
Within the freshwater and saltwater environments, they are important primary pro-
ducers, which means they are at the beginning of the food chain for other organisms.
During their growth phase, they are important oxygen-generating organisms and
constitute a significant portion of the plankton in water.
