1 Chlorophylls in Microalgae: Occurrence …
13
protochlorophyllide, not to other chlorophylls. Figure 1.5 shows the structure of
chlorophyll c. Additional studies on the biosynthesis of Chl c and their role in the
Chromophyte algae are clearly needed (Chen 2014).
Chlorophyll d was first identified in Rhodophyta in 1943 (Manning and Strain
1943) as a minor, green, and Mg containing pigment. At first, and because of its
structural similarity to an oxidation derivative of Chl a, Chl d was speculated to be
an artifact due to algae aging or even generated during pigment extraction process.
However, in the late nineties its discovery in the oxygenic photosynthetic prokaryote
organism Acaryochloris marina, a Cyanobacteria, in which Chl d is an important
primary photosynthetic pigment, confirmed the natural origin of Chl d (Cahoon and
Timko 2003, Miyashita et al. 1996, 1997, Partensky and Garczarek 2003).
Schliep et al. (2013) proposed that in A. marina Chl d may replace Chl a in a
photochemical role in PSI and PSII, but Chl d would be important in the near-infrared
light (700–750 nm). Chen (2014) reported that in A. marina, Chl d accomplishes 95%
of the photosynthetic pigments, while Chl a just 5%. In other oxygenic photosynthesis
conditions, Chl a is likely to dominate. As pointed in Larkum (2016), the nearinfrared light is the region where bacteriochlorophylls are active for anoxygenic
photosynthesis.
Chlorophyll f is the most recently discovered chlorophyll. It absorbs in the farred light, particularly in 700–800 nm region of the light spectra. This pigment was
first described in cyanobacteria that colonize niches that are rich in the far-red light
and near-infrared light, such as caves (cavernous cyanobacteria), soils, plant shaded
areas (Behrendt et al. 2015, Ho et al. 2017, Shen et al. 2019). They thrive in such
environment through an acclimation process known as far-red light photoacclimation
(FaRLiP), whereby ~ 8% of Chl a molecules in the photosystems are replaced by Chl
f , and a small amount of Chl d is produced (~1%) (Kurashov et al. 2019). The presence
of chl f permits the cyanobacteria to expand the light absorbing range for oxygenic
photosynthesis down to the near-infrared light and up to 800 nm (Ho et al. 2016).
This in turn allows them to access 33% more photons than organisms that do not
have Chl f and that are able to absorb just visible light (Chen and Blankenship 2011).
Gan et al. (2014), Ho et al. (2017), and Herrera-Salgado et al. (2018) showed that
PSII, PSI, and phycobilisomes are involved in the FaRLiP process. It has been shown
that while Chl f is associated with PSII and PSI, Chl d is exclusively associated with
PSII (Ho 2018, Nurnberg et al. 2018). It is known that chlorophyll d is synthesized
from Chl a, but the synthesis of chlorophyll c and f from chlorophyll a needs to be
clarified (Chen 2014, Ho et al. 2016).
References
Allakhverdiev, S. I., Kreslavski, V. D., Zharmukhamedov, S. K., Voloshin, R. A., Korol’kova, D.
V., Tomo, T., & Shen, J. R. (2016). Chlorophylls d and f and their role in primary photosynthetic
processes of cyanobacteria. Biochemistry (Moscow), 81(3), 201–212.
13
protochlorophyllide, not to other chlorophylls. Figure 1.5 shows the structure of
chlorophyll c. Additional studies on the biosynthesis of Chl c and their role in the
Chromophyte algae are clearly needed (Chen 2014).
Chlorophyll d was first identified in Rhodophyta in 1943 (Manning and Strain
1943) as a minor, green, and Mg containing pigment. At first, and because of its
structural similarity to an oxidation derivative of Chl a, Chl d was speculated to be
an artifact due to algae aging or even generated during pigment extraction process.
However, in the late nineties its discovery in the oxygenic photosynthetic prokaryote
organism Acaryochloris marina, a Cyanobacteria, in which Chl d is an important
primary photosynthetic pigment, confirmed the natural origin of Chl d (Cahoon and
Timko 2003, Miyashita et al. 1996, 1997, Partensky and Garczarek 2003).
Schliep et al. (2013) proposed that in A. marina Chl d may replace Chl a in a
photochemical role in PSI and PSII, but Chl d would be important in the near-infrared
light (700–750 nm). Chen (2014) reported that in A. marina, Chl d accomplishes 95%
of the photosynthetic pigments, while Chl a just 5%. In other oxygenic photosynthesis
conditions, Chl a is likely to dominate. As pointed in Larkum (2016), the nearinfrared light is the region where bacteriochlorophylls are active for anoxygenic
photosynthesis.
Chlorophyll f is the most recently discovered chlorophyll. It absorbs in the farred light, particularly in 700–800 nm region of the light spectra. This pigment was
first described in cyanobacteria that colonize niches that are rich in the far-red light
and near-infrared light, such as caves (cavernous cyanobacteria), soils, plant shaded
areas (Behrendt et al. 2015, Ho et al. 2017, Shen et al. 2019). They thrive in such
environment through an acclimation process known as far-red light photoacclimation
(FaRLiP), whereby ~ 8% of Chl a molecules in the photosystems are replaced by Chl
f , and a small amount of Chl d is produced (~1%) (Kurashov et al. 2019). The presence
of chl f permits the cyanobacteria to expand the light absorbing range for oxygenic
photosynthesis down to the near-infrared light and up to 800 nm (Ho et al. 2016).
This in turn allows them to access 33% more photons than organisms that do not
have Chl f and that are able to absorb just visible light (Chen and Blankenship 2011).
Gan et al. (2014), Ho et al. (2017), and Herrera-Salgado et al. (2018) showed that
PSII, PSI, and phycobilisomes are involved in the FaRLiP process. It has been shown
that while Chl f is associated with PSII and PSI, Chl d is exclusively associated with
PSII (Ho 2018, Nurnberg et al. 2018). It is known that chlorophyll d is synthesized
from Chl a, but the synthesis of chlorophyll c and f from chlorophyll a needs to be
clarified (Chen 2014, Ho et al. 2016).
References
Allakhverdiev, S. I., Kreslavski, V. D., Zharmukhamedov, S. K., Voloshin, R. A., Korol’kova, D.
V., Tomo, T., & Shen, J. R. (2016). Chlorophylls d and f and their role in primary photosynthetic
processes of cyanobacteria. Biochemistry (Moscow), 81(3), 201–212.