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This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. October Learn how and when to remove this template message Most growers prefer monocultural production and go to considerable lengths to maintain the purity of their cultures.
However, the microbiological contaminants are still under investigation. Individual species cultures are also much needed for research purposes. A common method of obtaining pure cultures is serial dilution.
Cultivators dilute either a wild sample or a lab sample containing the desired algae with filtered water and introduce small aliquots measures of this solution into a large number of small growing containers.
Dilution follows a microscopic examination of the source culture that predicts that a few of the growing containers contain a single cell of the desired species.
Following a suitable period on a light table, cultivators again use the microscope to identify containers to start larger cultures. Another approach is to use a special medium which excludes other organisms, including invasive algae. For example, Dunaliella is a commonly grown genus of microalgae which flourishes in extremely salty water that few other organisms can tolerate.
Alternatively, mixed algae cultures can work well for larval mollusks. First, the cultivator filters the sea water to remove algae which are too large for the larvae to eat.
Next, the cultivator adds nutrients and possibly aerates the result. After one or two days in a greenhouse or outdoors, the resulting thin soup of mixed algae is ready for the larvae.
An advantage of this method is low maintenance. Seaweed cultivator and Culture of microalgae in hatcheries Microalgae is used to culture brine shrimpwhich produce dormant eggs pictured.
The eggs can then be hatched on demand and fed to cultured fish larvae and crustaceans. Water, carbon dioxideminerals and light are all important factors in cultivation, and different algae have different requirements. It is also possible to grow certain types of algae without light, these types of algae consume sugars such as glucose.
This is known as heterotrophic growth. As the algae grow and multiply, the culture becomes so dense that it blocks light from reaching deeper into the water. To use deeper ponds, growers agitate the water, circulating the algae so that it does not remain on the surface. Paddle wheels can stir the water and compressed air coming from the bottom lifts algae from the lower regions.
Agitation also helps prevent over-exposure to the sun. Another means of supplying light is to place the light in the system. Glow plates made from sheets of plastic or glass and placed within the tank offer precise control over light intensity, and distribute it more evenly.
They are seldom used, however, due to high cost. Odor and oxygen[ edit ] The odor associated with bogsswampsindeed any stagnant waters, can be due to oxygen depletion caused by the decay of deceased algal blooms. Under anoxic conditions, the bacteria inhabiting algae cultures break down the organic material and produce hydrogen sulfide and ammonia which causes the odor.
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