19 Use of Microalgae Pigments in Aquaculture
495
(García-Malea et al. 2009). García-Malea et al. (2009) have reported that a high aerial
biomass production rate of 33.1 g-ds/m
2 /day on a Haematococcus sp. was obtained
in a high light intensity of 1250 μE m
−2 s
−1 . At that time a low astaxanthin content
of 0.11 mg/g-ds was achieved, meaning that the cells in the condition were under
the green stage even in the strong light condition. According to previous reports on
Haematococcus spp., the astaxanthin content in the dry biomass of Haematococcus
cell can be increased up to 5% in the red stage (Bubrick 1991; Harker et al. 1996).
This indicated that the content of the pigment obtained in Haematococcus was quite
high compared with the other carotenoids such as β-carotene and lutein in other
microalgae. Although astaxanthin can be accumulated in a green microalga Chlorella
zofingiensis, the content is much lower than that of Haematococcus sp. (Del Campo
et al. 2004). Thus, Haematococcus sp. is usually utilized for the commercial scale
production of astaxanthin from microalgae.
The production of lutein on microalgae has also been carried out throughout
the two step processes, same as the production of astaxanthin. The candidates for
astaxanthin production are only Haematococcus species, whereas the candidates for
lutein production have not been restricted to a particular species yet: Chlamydomonas
sp., Chlorella zofingiensis, Chlorococcum citriforme, Dunaliella salina, Muriellopsis
sp., Neospongiococcus gelatinosum, Scenedesmus almeriensis (Table 19.4). Though
the lutein content in previous studies is much less than the content of astaxanthin, the
areal production rate of lutein has reached the same level as astaxanthin production
rates. However, the lutein producer was a terrestrial plant marigold (Lin et al. 2015).
The high biomass production rates of 50–60 g-dw m
−2 day
−1 obtained by microalgae
had been reported only in a small scale reactor (Del Campo et al. 2000; Sánchez et al.
2008). If improvement of biotechnology in the production, especially in the cost, can
be achieved in commercial scale, the lutein production may be developed using
microalgae. In addition to the improvement in large scale process, enhancement of
the cellular lutein content should be also important due to its low content compared
with the content of astaxanthin in Haematococcus species (Table 19.4).
Because fucoxanthin is the main carotenoid for brown algae, a large number
of species including Chaetoceros gracilis, Isochrysis galbana and Phaeodactylum
tricornutum have been observed as potential candidates for fucoxanthin production
(Table 19.5). Fucoxanthin has been known as a primary carotenoid of microalgae,
while both astaxanthin and lutein are categorized as secondary carotenoids. In general
primary carotenoids are naturally accumulated in the cell without any stress, meaning
that the fucoxanthin production can be operated in one step. To avoid inefficient accumulation of fucoxanthin under high light intensity, many researches have operated
at relatively low light intensity of below 200 μE m
−2 s
−1 . However, the biomass
production rate is limited by the low light condition, which is necessary for effective
fucoxanthin accumulation, resulting in relatively low production rates of fucoxanthin
(McClure et al. 2018).
Furthermore, microalgae can accumulate other carotenoids such as β-carotene,
canthaxanthin and zeaxanthin in the cell (Table 19.6). It has been reported that βcarotene can be accumulated up to 100 mg g-dw
−1 by a green microalga, Dunaliella
salina, especially under the combination of high salinity, nutrient deficiency and high
495
(García-Malea et al. 2009). García-Malea et al. (2009) have reported that a high aerial
biomass production rate of 33.1 g-ds/m
2 /day on a Haematococcus sp. was obtained
in a high light intensity of 1250 μE m
−2 s
−1 . At that time a low astaxanthin content
of 0.11 mg/g-ds was achieved, meaning that the cells in the condition were under
the green stage even in the strong light condition. According to previous reports on
Haematococcus spp., the astaxanthin content in the dry biomass of Haematococcus
cell can be increased up to 5% in the red stage (Bubrick 1991; Harker et al. 1996).
This indicated that the content of the pigment obtained in Haematococcus was quite
high compared with the other carotenoids such as β-carotene and lutein in other
microalgae. Although astaxanthin can be accumulated in a green microalga Chlorella
zofingiensis, the content is much lower than that of Haematococcus sp. (Del Campo
et al. 2004). Thus, Haematococcus sp. is usually utilized for the commercial scale
production of astaxanthin from microalgae.
The production of lutein on microalgae has also been carried out throughout
the two step processes, same as the production of astaxanthin. The candidates for
astaxanthin production are only Haematococcus species, whereas the candidates for
lutein production have not been restricted to a particular species yet: Chlamydomonas
sp., Chlorella zofingiensis, Chlorococcum citriforme, Dunaliella salina, Muriellopsis
sp., Neospongiococcus gelatinosum, Scenedesmus almeriensis (Table 19.4). Though
the lutein content in previous studies is much less than the content of astaxanthin, the
areal production rate of lutein has reached the same level as astaxanthin production
rates. However, the lutein producer was a terrestrial plant marigold (Lin et al. 2015).
The high biomass production rates of 50–60 g-dw m
−2 day
−1 obtained by microalgae
had been reported only in a small scale reactor (Del Campo et al. 2000; Sánchez et al.
2008). If improvement of biotechnology in the production, especially in the cost, can
be achieved in commercial scale, the lutein production may be developed using
microalgae. In addition to the improvement in large scale process, enhancement of
the cellular lutein content should be also important due to its low content compared
with the content of astaxanthin in Haematococcus species (Table 19.4).
Because fucoxanthin is the main carotenoid for brown algae, a large number
of species including Chaetoceros gracilis, Isochrysis galbana and Phaeodactylum
tricornutum have been observed as potential candidates for fucoxanthin production
(Table 19.5). Fucoxanthin has been known as a primary carotenoid of microalgae,
while both astaxanthin and lutein are categorized as secondary carotenoids. In general
primary carotenoids are naturally accumulated in the cell without any stress, meaning
that the fucoxanthin production can be operated in one step. To avoid inefficient accumulation of fucoxanthin under high light intensity, many researches have operated
at relatively low light intensity of below 200 μE m
−2 s
−1 . However, the biomass
production rate is limited by the low light condition, which is necessary for effective
fucoxanthin accumulation, resulting in relatively low production rates of fucoxanthin
(McClure et al. 2018).
Furthermore, microalgae can accumulate other carotenoids such as β-carotene,
canthaxanthin and zeaxanthin in the cell (Table 19.6). It has been reported that βcarotene can be accumulated up to 100 mg g-dw
−1 by a green microalga, Dunaliella
salina, especially under the combination of high salinity, nutrient deficiency and high