226 Marine Macro- and Microalgae: An Overview
cells mL
−1
were achieved, as well as 250 to 2,500 µg L
−1
of yessotoxins (Loader et al. 2007). Parker
et al. (2002) successfully cultured dinoflagellate Alexandrium minutum, implementing a classical PBR
design—the flat alveolar panel (Tredici et al. 1991), but resorting to smaller volumes (4 L), with a light
path length of 12 mm, at ca. 100 µmol photons m
−2
s
−1
, a light cycle of 12 h/12 h and low aeration
(0.2 vvm), and attained a productivity of 14,000 cells mL
−1
d
−1
and 20 µgL
−1
d
−1
of gonyautoxin (Parker et
al. 2002). An improved classical stirred PBR of 15 L was tested by Camacho et al. (2011) for cultivation
of Protoceratium reticulatum. The bioreactor was made of 5 mm-thick borosilicate glass, with internal
diameter of 19.3 cm, bearing a spin filter with diameter of 7 cm, and height of 22 cm. A perforated
pipe air sparger was placed within the spin filter, in order to prevent direct gas sparging of algal cells.
The culture mixing/stirring was performed by resorting to three-bladed marine propeller, located 5 cm
above the bottom of the vessel. PBR illumination required up to five fluorescent lamps, mounted around
its periphery. Temperature control was affected by resorting to circulating, thermostatted water through
the glass jacket surrounding the PBR. The pH was controlled by automatic injection of CO 2 within the
spin filter. Experiments included perfusion culture (i.e., the cells remained in the bioreactor), fed-batch,
and semicontinuous modes, and average cell and yessotoxin productivities of 5,228 cells mL
−1
d
−1
and
9.16 µgL
−1
d
−1
, respectively, were reported (García-Camacho et al. 2011).
Jauffrais et al. (2012) have successfully conducted an experiment with toxic dinoflagellate Azadinium
spinosum, using two column-stirred-PBRs in series (about 100 L each), operated continuouswise with
light intensity of 200 µmol photons m
−2
·s
−1
, under light cycles of 16 h/8 h, low stirring (40 rpm) and air
bubbling—and obtained 190,000 and 210,000 cell mL
−1
(steady state), with a maximum azaspiracid
production of 475 ± 17 µg·d
−1
(Jauffrais et al. 2012).
Medhioub et al. (2011) have conducted another study with Alexandrium ostenfeldii in flat-bottom
flasks (8 L), in batch mode and continuous column-stirred-PBR (100 L), to produce spirolide toxins. The
batch cultures ran with a photon irradiance rate of 155 µmol m
–2
s
–1
, under a 12 h/12 h light/dark regime
with gentle aeration for 18 d. In continuous-flow culture (stirred-PBR), experiments were carried out
under an irradiance rate of 188 µmol m
–2
s
–1
, 16h/8h light and dark cycles, automated pH and temperature
control, with gentle aeration and stirring provided by four impeller turbines (50 rpm) for ~ 130 d. The
latter conditions allowed values of cell concentration up to 70,000 cells mL
–1
, for more than 60 d, and the
maximum value attained in the batch mode was 16,788 cells mL
–1
and spirolide toxin content of 34 to
50 µg L
–1
(Medhioub et al. 2011).
Wang et al. (2015) also developed a large-scale production method for benthic dinoflagellate
Prorocentrum lima, using a vertical flat PBR with dimensions 60 cm x 60 cm x 28 cm and volume of 100
L. Light was provided by 4 W fluorescent lamps (white light), placed at the bottom of PBR, with intensity
thereof controlled by changing number of lamps. The PBR was equipped with a gas-filled tube in the four
corners, and the center of the reactor received the aeration system, with an aeration rate of 0.08 vvm that
also provided appropriate mixing. The experiment was performed under batch conditions for 35 d, and
a maximum cell count of 24,600 cells mL
–1
was attained, ca. 3.2 g of dry algal powder and 115.2 mg of
PSP toxins (okadaic acid plus dinophysis toxins) (Wang et al. 2015).
Rahman et al. (2016) have likewise employed a vertical column PBR for three benthic dinoflagellates,
Amphidinium carterae, Prorocentrum rathymum, and Symbiodinium sp., with a total capacity of
~ 700 L (12 columns with 60 L each, connected to each other). The light intensities at stake varied between
40–50 µmol m
–2
s
–1
, the light/night cycle was 12 h/12 h and moderate aeration and mixing facilitated by
circulation of the culture between columns. Biomass yields attained 0.226 g L
–1
, 0.183 g L
–1
, 0.173 g L
–1
for Amphidinium carterae, Prorocentrum rathymum, and Symbiodinium sp., respectively (Rahman et al.
2016).
Fuentes et al. (2016) have studied only the production of biomass of Amphidinium carterae and
several metabolites (i.e., pigments, lipids) thereby, using airlift column PBR indoors and outdoors—and
proved that this dinoflagellate can be exploited in a larger scale. Different culture volumes were tested:
a PBR with 540 L was tested indoors, with light path of 10 cm, comprising three columns connected
to a central tube that allow the mixing of the medium; then cultures were transferred to a PBR with a
working volume of 320 L, a shorter light path of 5 cm but the same configuration; an airlift column PBR
was finally tested outdoors with a small working volume (48 L) and a light path of 5 cm. All PBRs were
cells mL
−1
were achieved, as well as 250 to 2,500 µg L
−1
of yessotoxins (Loader et al. 2007). Parker
et al. (2002) successfully cultured dinoflagellate Alexandrium minutum, implementing a classical PBR
design—the flat alveolar panel (Tredici et al. 1991), but resorting to smaller volumes (4 L), with a light
path length of 12 mm, at ca. 100 µmol photons m
−2
s
−1
, a light cycle of 12 h/12 h and low aeration
(0.2 vvm), and attained a productivity of 14,000 cells mL
−1
d
−1
and 20 µgL
−1
d
−1
of gonyautoxin (Parker et
al. 2002). An improved classical stirred PBR of 15 L was tested by Camacho et al. (2011) for cultivation
of Protoceratium reticulatum. The bioreactor was made of 5 mm-thick borosilicate glass, with internal
diameter of 19.3 cm, bearing a spin filter with diameter of 7 cm, and height of 22 cm. A perforated
pipe air sparger was placed within the spin filter, in order to prevent direct gas sparging of algal cells.
The culture mixing/stirring was performed by resorting to three-bladed marine propeller, located 5 cm
above the bottom of the vessel. PBR illumination required up to five fluorescent lamps, mounted around
its periphery. Temperature control was affected by resorting to circulating, thermostatted water through
the glass jacket surrounding the PBR. The pH was controlled by automatic injection of CO 2 within the
spin filter. Experiments included perfusion culture (i.e., the cells remained in the bioreactor), fed-batch,
and semicontinuous modes, and average cell and yessotoxin productivities of 5,228 cells mL
−1
d
−1
and
9.16 µgL
−1
d
−1
, respectively, were reported (García-Camacho et al. 2011).
Jauffrais et al. (2012) have successfully conducted an experiment with toxic dinoflagellate Azadinium
spinosum, using two column-stirred-PBRs in series (about 100 L each), operated continuouswise with
light intensity of 200 µmol photons m
−2
·s
−1
, under light cycles of 16 h/8 h, low stirring (40 rpm) and air
bubbling—and obtained 190,000 and 210,000 cell mL
−1
(steady state), with a maximum azaspiracid
production of 475 ± 17 µg·d
−1
(Jauffrais et al. 2012).
Medhioub et al. (2011) have conducted another study with Alexandrium ostenfeldii in flat-bottom
flasks (8 L), in batch mode and continuous column-stirred-PBR (100 L), to produce spirolide toxins. The
batch cultures ran with a photon irradiance rate of 155 µmol m
–2
s
–1
, under a 12 h/12 h light/dark regime
with gentle aeration for 18 d. In continuous-flow culture (stirred-PBR), experiments were carried out
under an irradiance rate of 188 µmol m
–2
s
–1
, 16h/8h light and dark cycles, automated pH and temperature
control, with gentle aeration and stirring provided by four impeller turbines (50 rpm) for ~ 130 d. The
latter conditions allowed values of cell concentration up to 70,000 cells mL
–1
, for more than 60 d, and the
maximum value attained in the batch mode was 16,788 cells mL
–1
and spirolide toxin content of 34 to
50 µg L
–1
(Medhioub et al. 2011).
Wang et al. (2015) also developed a large-scale production method for benthic dinoflagellate
Prorocentrum lima, using a vertical flat PBR with dimensions 60 cm x 60 cm x 28 cm and volume of 100
L. Light was provided by 4 W fluorescent lamps (white light), placed at the bottom of PBR, with intensity
thereof controlled by changing number of lamps. The PBR was equipped with a gas-filled tube in the four
corners, and the center of the reactor received the aeration system, with an aeration rate of 0.08 vvm that
also provided appropriate mixing. The experiment was performed under batch conditions for 35 d, and
a maximum cell count of 24,600 cells mL
–1
was attained, ca. 3.2 g of dry algal powder and 115.2 mg of
PSP toxins (okadaic acid plus dinophysis toxins) (Wang et al. 2015).
Rahman et al. (2016) have likewise employed a vertical column PBR for three benthic dinoflagellates,
Amphidinium carterae, Prorocentrum rathymum, and Symbiodinium sp., with a total capacity of
~ 700 L (12 columns with 60 L each, connected to each other). The light intensities at stake varied between
40–50 µmol m
–2
s
–1
, the light/night cycle was 12 h/12 h and moderate aeration and mixing facilitated by
circulation of the culture between columns. Biomass yields attained 0.226 g L
–1
, 0.183 g L
–1
, 0.173 g L
–1
for Amphidinium carterae, Prorocentrum rathymum, and Symbiodinium sp., respectively (Rahman et al.
2016).
Fuentes et al. (2016) have studied only the production of biomass of Amphidinium carterae and
several metabolites (i.e., pigments, lipids) thereby, using airlift column PBR indoors and outdoors—and
proved that this dinoflagellate can be exploited in a larger scale. Different culture volumes were tested:
a PBR with 540 L was tested indoors, with light path of 10 cm, comprising three columns connected
to a central tube that allow the mixing of the medium; then cultures were transferred to a PBR with a
working volume of 320 L, a shorter light path of 5 cm but the same configuration; an airlift column PBR
was finally tested outdoors with a small working volume (48 L) and a light path of 5 cm. All PBRs were