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N. A. H. El Semary
Faded colours or discolouration of fishes would reduce their market value [6].
According to [13], the application of carotenoids is important to tiger shrimps as
their deficiency can lead to discoloration called “Blue disease”.
3.1 The Use of Haematococcus Alga for Astaxanthin
Production
In nature, algae such as Haematococcus pulivaris synthesizes the carotenoid pigment astaxanthin which is transferred through the food web to zooplankton and
crustaceans, which in turn are prey for salmonoids and trout [14]. Astaxanthin is
biosynthesized through the isoprenoid pathway which proceed from acetyl-Co-A,
phytoene, lycopene, carotene, and canthaxanthin and then astaxanthin. According
to [15], Haematococcus pluvialis is a green alga belonging to family Haematococcaceae, order Volvocales. This alga predominates in temporary water bodies near
marine water bodies via its ability to cope under conditions of extreme fluctuations
in light, temperature and salinity levels due to its rapid ability to encyst [16]. There are
four types of cells in the life cycle of this alga: microzooids, large flagellated macrozooids, non-motile palmella forms; and haematocysts, which are large red cells with
a heavy resistant cell wall. When environmental conditions become unfavorable the
palmella stage results, followed by the resistant haematocysts and the accumulation
of astaxanthin where same conditions apply for encystment and carotenogenesis as
the two phenomena usually occur together. This alga does not produce toxin. Its mean
protein content is 23.62%, carbohydrate 38%, fats 13%, and its mineral composition
includes Fe, Mg, Ca as well as vitamins belonging to vitamin B complex, vitamin
C, vitamin E and its astxanthin content is 1%.
[17] reported that under light conditions astaxanthin can be produced whereas in
the dark it can be produced only if an organic carbon source is present. Carotenogensis and encystment can be induced by low nitrate or phosphate, high temperature
or light, or the addition of sodium chloride in the culture medium [18, 19]. When
Haematococcus cultures are exposed to continuous light ∼350 µmol m
−2 , astaxanthin formation is increased [20]. Other studies support the major role of astaxanthin
accumulation in Haematococcus as a form of protection against high light and oxygen
radicals [21]. Carotenoid bio-synthesis in cystsis also enhanced by oxidative stresses
[22]. According to [15] the industrial production of Haematococcus alga involves
growing pure cultures in closed culture container with regulated pH and temperature.
After suitable growth, cultures are transferred to open culture system ponds under
the proper stress conditions such as high light intensity to allow carotenogenesis and
encystment. Algal cysts then open to allow standardized production of Astaxanthin.
N. A. H. El Semary
Faded colours or discolouration of fishes would reduce their market value [6].
According to [13], the application of carotenoids is important to tiger shrimps as
their deficiency can lead to discoloration called “Blue disease”.
3.1 The Use of Haematococcus Alga for Astaxanthin
Production
In nature, algae such as Haematococcus pulivaris synthesizes the carotenoid pigment astaxanthin which is transferred through the food web to zooplankton and
crustaceans, which in turn are prey for salmonoids and trout [14]. Astaxanthin is
biosynthesized through the isoprenoid pathway which proceed from acetyl-Co-A,
phytoene, lycopene, carotene, and canthaxanthin and then astaxanthin. According
to [15], Haematococcus pluvialis is a green alga belonging to family Haematococcaceae, order Volvocales. This alga predominates in temporary water bodies near
marine water bodies via its ability to cope under conditions of extreme fluctuations
in light, temperature and salinity levels due to its rapid ability to encyst [16]. There are
four types of cells in the life cycle of this alga: microzooids, large flagellated macrozooids, non-motile palmella forms; and haematocysts, which are large red cells with
a heavy resistant cell wall. When environmental conditions become unfavorable the
palmella stage results, followed by the resistant haematocysts and the accumulation
of astaxanthin where same conditions apply for encystment and carotenogenesis as
the two phenomena usually occur together. This alga does not produce toxin. Its mean
protein content is 23.62%, carbohydrate 38%, fats 13%, and its mineral composition
includes Fe, Mg, Ca as well as vitamins belonging to vitamin B complex, vitamin
C, vitamin E and its astxanthin content is 1%.
[17] reported that under light conditions astaxanthin can be produced whereas in
the dark it can be produced only if an organic carbon source is present. Carotenogensis and encystment can be induced by low nitrate or phosphate, high temperature
or light, or the addition of sodium chloride in the culture medium [18, 19]. When
Haematococcus cultures are exposed to continuous light ∼350 µmol m
−2 , astaxanthin formation is increased [20]. Other studies support the major role of astaxanthin
accumulation in Haematococcus as a form of protection against high light and oxygen
radicals [21]. Carotenoid bio-synthesis in cystsis also enhanced by oxidative stresses
[22]. According to [15] the industrial production of Haematococcus alga involves
growing pure cultures in closed culture container with regulated pH and temperature.
After suitable growth, cultures are transferred to open culture system ponds under
the proper stress conditions such as high light intensity to allow carotenogenesis and
encystment. Algal cysts then open to allow standardized production of Astaxanthin.