Bioprospecting of Marine Microalgae, Corals and Microorganisms 179
pharmaceuticals, as substitutes for synthetic dyes. The all-trans-β-carotene
and isomers and other minor carotenoids isolated from Dunaliella salina
have been recognized as good antioxidants. The phycobiliproteins are
water soluble pigments consisting of red-colored phycoerythrin and bluecolored phycocyanin and allophycocyanin. Botryococcus braunii is a green
colonial microalga that is used mainly for the production of carotenoids,
hydrocarbons and polysaccharides. Commercial scale production of
some microalgal pigments such as β-carotene from Dunaliella, astaxanthin
from Haematococcus and lutein from chlorophycean strains have been
initiated. Extracted β-carotene is sold mostly in vegetable oil ranging in
concentrations from 1 to 20% to color various food products in soft gels for
personal uses. The purifi ed natural β-carotene is generally accompanied
by other carotenoids of Dunaliella, predominantly lutein, neoxanthin,
zeaxanthin, violaxanthin, cryptoxanthin, and α-carotene (Arad and Yaron,
1992; Jeffrey et al., 1997; Shi et al., 2002; Campo et al., 2007). The advantages
of carotenoids production by microalgae are given in Table 7.2.
Similar to marine fatty fi sh such as cod, herring, tuna, and others,
microalgae are also sources of polyunsaturated fatty acids (PUFA) (Berge
and Barnathan, 2005). Under certain conditions such as algal bloom, the
proportion of PUFA of the omega-3 type can reach 50% of total lipids.
Because of therapeutic importance of these fatty acids, and paucity of
availability of marine fi shes as their conventional sources, there has been
interest in cultivation of microalgae for large scale production of PUFA.
Chlorella is an important source of PUFAs (Adams, 1997; Tokusoglu and
Unal, 2003). The PUFA, DHA (docosahexaenoic acid), has been produced
by heterotrophically grown Crypthecodinium cohnii. These algal DHA are
used as food supplements such as infant formula. Algal PUFA can be used
for nutritional enrichment of food products and also for production of
PUFA-enriched fi sh feeds. Haptophyta biomass is used as feed for bivalve
mollusks, crustacean larvae and zooplankton which in turn, is used as
feed for fi sh and crustacean larvae. The polysaccharide of unicellular
rhodophyte, Porphyridium spp. has potential as a thickening agent and food
additive because of its high viscosity over a wide range of pH, temperature
and salinity (Jeffrey et al., 1997). Table 7.3 gives some bioactive compounds
produced by microalgae.
Table 7.2 Advantages of cultivation of microalgae
Ease of cultivation
High pigment production (3-5% on dry weight basis)
Have both cis and trans isomers of carotenoids
The algae protein is nutritive and can be used as protein supplements
The algal biomass can be used as poultry feed
pharmaceuticals, as substitutes for synthetic dyes. The all-trans-β-carotene
and isomers and other minor carotenoids isolated from Dunaliella salina
have been recognized as good antioxidants. The phycobiliproteins are
water soluble pigments consisting of red-colored phycoerythrin and bluecolored phycocyanin and allophycocyanin. Botryococcus braunii is a green
colonial microalga that is used mainly for the production of carotenoids,
hydrocarbons and polysaccharides. Commercial scale production of
some microalgal pigments such as β-carotene from Dunaliella, astaxanthin
from Haematococcus and lutein from chlorophycean strains have been
initiated. Extracted β-carotene is sold mostly in vegetable oil ranging in
concentrations from 1 to 20% to color various food products in soft gels for
personal uses. The purifi ed natural β-carotene is generally accompanied
by other carotenoids of Dunaliella, predominantly lutein, neoxanthin,
zeaxanthin, violaxanthin, cryptoxanthin, and α-carotene (Arad and Yaron,
1992; Jeffrey et al., 1997; Shi et al., 2002; Campo et al., 2007). The advantages
of carotenoids production by microalgae are given in Table 7.2.
Similar to marine fatty fi sh such as cod, herring, tuna, and others,
microalgae are also sources of polyunsaturated fatty acids (PUFA) (Berge
and Barnathan, 2005). Under certain conditions such as algal bloom, the
proportion of PUFA of the omega-3 type can reach 50% of total lipids.
Because of therapeutic importance of these fatty acids, and paucity of
availability of marine fi shes as their conventional sources, there has been
interest in cultivation of microalgae for large scale production of PUFA.
Chlorella is an important source of PUFAs (Adams, 1997; Tokusoglu and
Unal, 2003). The PUFA, DHA (docosahexaenoic acid), has been produced
by heterotrophically grown Crypthecodinium cohnii. These algal DHA are
used as food supplements such as infant formula. Algal PUFA can be used
for nutritional enrichment of food products and also for production of
PUFA-enriched fi sh feeds. Haptophyta biomass is used as feed for bivalve
mollusks, crustacean larvae and zooplankton which in turn, is used as
feed for fi sh and crustacean larvae. The polysaccharide of unicellular
rhodophyte, Porphyridium spp. has potential as a thickening agent and food
additive because of its high viscosity over a wide range of pH, temperature
and salinity (Jeffrey et al., 1997). Table 7.3 gives some bioactive compounds
produced by microalgae.
Table 7.2 Advantages of cultivation of microalgae
Ease of cultivation
High pigment production (3-5% on dry weight basis)
Have both cis and trans isomers of carotenoids
The algae protein is nutritive and can be used as protein supplements
The algal biomass can be used as poultry feed