4 Carotenoid Synthesis and Accumulation in Microalgae …
75
of psy, pds, lyc, and chy genes, while blue light was more effective in the induction
of astaxanthin accumulation in H. pluvialis cells than red light. Furthermore, Steinbrenner and Linden (2003) indicated that the redox state of the plastoquinone pool
related to the light induction of carotenoid synthetic gene expression and astaxanthin
accumulation in H. pluvialis. In contrast, Bohne and Linden (2002) indicated that
the redox state of plastoquinone pool of the photosynthetic electron transport was no
relevant to the light-induced expression of psy and pds of C. reinhardtii.
Sun et al. (2010) reported that C. reinhardtii showed a clear diurnal expression
pattern of genes in methylerythritol phosphate (MEP) pathway for the biosynthesis
of isoprenoids and in the carotenoid metabolism, when the cells were grown under
a 12 h/12 h light/dark condition. In addition, Sun et al. (2010) revealed that C.
reinhardtii displayed higher transcript level of psy, pds, and lycopene β-cyclase
gene (lcyb) in the light period than those in the dark period and discussed that the
gene expression of dxs and geranylgeranyl pyrophosphate synthase gene (ggps)
of isoprenoid biosynthetic pathway and of lcyb was co-regulated by the internal
circadian clock and external light signals.
4.4.3 Temperature-Stimulated Carotenoid Accumulation
Temperature is also one of the major environmental stimuli which can alter the
photosynthetic pigment production as well as light. Campo et al. (2004) reported that,
in a temperature range from 20 to 28 °C, higher temperature induced higher cellular
content of lutein in C. zofingiensis cells. At elevated temperatures over 30 °C, H.
pluvialis showed 15- to 20-fold increases in the cellular carotenoid content compared
with the algal cells cultured at 20 °C (Tjahjono et al. 1994). In D. salina, Gómez
and González (2005) reported that the β-carotene content was higher at 26 °C than
at 15 °C and that temperature considered to be more effective than irradiance in
changing the carotenoid composition.
Decreasing temperature can also stimulate the carotenoid production in
microalgae. In Dunaliella bardawil, Ben-Amotz (1996) reported that decreasing
temperature from 30 to 10 °C caused a 2-fold increase in the cellular β-carotene
content without any significant change of the cellular chlorophyll content resulting
in an increase of the β-carotene/chlorophyll ratio from 4.4 at 30 °C to 8.5 at 10 °C.
Orset and Young (1999) revealed that, when D. salina cells were transferred from
34 to 17 °C, the cells showed a 7.5-fold increase in α-carotene level. Furthermore,
decreasing growth temperatures can alter isomeric composition of carotenoids such
as β-carotene in D. bardawil (Ben-Amotz 1996) and D. salina (Orset and Young
1999) and diatoxanthin in E. gracilis (Kato et al. 2019).
Król et al. (1997) showed that cultivation at 13 °C induced a 5-fold increase
in the pool size of xanthophyll cycle pigments (violaxanthin + antheraxanthin +
zeaxanthin) in D. salina cells on chlorophyll a basis compared with cells grown
at 30 °C under 150 μmol photon m
−2 s
−1 . Król et al. (1997) also revealed that
the low temperature-induced accumulation of carotenoids in D. salina cells was the
75
of psy, pds, lyc, and chy genes, while blue light was more effective in the induction
of astaxanthin accumulation in H. pluvialis cells than red light. Furthermore, Steinbrenner and Linden (2003) indicated that the redox state of the plastoquinone pool
related to the light induction of carotenoid synthetic gene expression and astaxanthin
accumulation in H. pluvialis. In contrast, Bohne and Linden (2002) indicated that
the redox state of plastoquinone pool of the photosynthetic electron transport was no
relevant to the light-induced expression of psy and pds of C. reinhardtii.
Sun et al. (2010) reported that C. reinhardtii showed a clear diurnal expression
pattern of genes in methylerythritol phosphate (MEP) pathway for the biosynthesis
of isoprenoids and in the carotenoid metabolism, when the cells were grown under
a 12 h/12 h light/dark condition. In addition, Sun et al. (2010) revealed that C.
reinhardtii displayed higher transcript level of psy, pds, and lycopene β-cyclase
gene (lcyb) in the light period than those in the dark period and discussed that the
gene expression of dxs and geranylgeranyl pyrophosphate synthase gene (ggps)
of isoprenoid biosynthetic pathway and of lcyb was co-regulated by the internal
circadian clock and external light signals.
4.4.3 Temperature-Stimulated Carotenoid Accumulation
Temperature is also one of the major environmental stimuli which can alter the
photosynthetic pigment production as well as light. Campo et al. (2004) reported that,
in a temperature range from 20 to 28 °C, higher temperature induced higher cellular
content of lutein in C. zofingiensis cells. At elevated temperatures over 30 °C, H.
pluvialis showed 15- to 20-fold increases in the cellular carotenoid content compared
with the algal cells cultured at 20 °C (Tjahjono et al. 1994). In D. salina, Gómez
and González (2005) reported that the β-carotene content was higher at 26 °C than
at 15 °C and that temperature considered to be more effective than irradiance in
changing the carotenoid composition.
Decreasing temperature can also stimulate the carotenoid production in
microalgae. In Dunaliella bardawil, Ben-Amotz (1996) reported that decreasing
temperature from 30 to 10 °C caused a 2-fold increase in the cellular β-carotene
content without any significant change of the cellular chlorophyll content resulting
in an increase of the β-carotene/chlorophyll ratio from 4.4 at 30 °C to 8.5 at 10 °C.
Orset and Young (1999) revealed that, when D. salina cells were transferred from
34 to 17 °C, the cells showed a 7.5-fold increase in α-carotene level. Furthermore,
decreasing growth temperatures can alter isomeric composition of carotenoids such
as β-carotene in D. bardawil (Ben-Amotz 1996) and D. salina (Orset and Young
1999) and diatoxanthin in E. gracilis (Kato et al. 2019).
Król et al. (1997) showed that cultivation at 13 °C induced a 5-fold increase
in the pool size of xanthophyll cycle pigments (violaxanthin + antheraxanthin +
zeaxanthin) in D. salina cells on chlorophyll a basis compared with cells grown
at 30 °C under 150 μmol photon m
−2 s
−1 . Król et al. (1997) also revealed that
the low temperature-induced accumulation of carotenoids in D. salina cells was the