Figure legends
Figure 1. a) Experimental program illustrating timing for the
three experimental phases and the sequencing of the eight reactors. The
temperature profiles for Phase III are based on historical climate data
in Fort Myers Florida. The Extreme Profile is based on summer
temperatures only; the average profile is based on annual average. Both
involve hourly temperature variations in the reactors. The Constant
Profile has constant values on a 12-12 cycle based on annual day and
night averages. b) Photobioreactor setup for cultures in Phase I where
Reactors A, B and C, D were cultivated at 20 °C and (b) Reactors E, F
and G, H were cultivated at 35 °C. Dye-1 and Dye-2 were the dummy
reactors used for monitoring temperature, and reactors W-1 and W-2 were
connected to the reactor exhaust and used as waste collectors due to
minor foaming and evaporation loss. Reactors are brought outside of the
incubator for sampling and photography.
Figure 2. OD (750 nm) results for cultures in three different
phases (a) AB and CD and (b) EF and GH at various temperature
treatments. Results shown are the average of two determinations with
error bars showing the range of values. Temperature conditions for the
various phases are shown.
Figure 3. Late-phase average biomass productivities ofArthrospira platensis at various temperature treatments in
three phases: Phase I temperature were 20 and 35 °C; in Phase II
temperature were 20, 30 and 35 °C and in Phase III 31 °C (CtSP), 32 °C
(AvSP) and 36 °C (ExSP), where temperature designations are the average
daytime values. Error bars are +/- one standard deviation for the
averages over multiple days of semi-continuous operation.
Figure 4 . Representative whole cell (WC) spectra of cultures at
different temperature treatments in the three phases of the experiment
(a) Phase I at 20 °C (A and C) and 35 °C (E and G), (b) Phase II at 35
°C (A), 30 °C (C) 20 °C (E) and 30 °C (G), and (c) Phase III with
Extreme Summer, ExSP (A), Average Summer, AvSP (C) and Constant Summer,
CtSP (G). The absorbance values are normalized to 1 gDW
L-1.
Figure 5. PC and Chl-a content (%, DW) in the three phases of
the experimental plan at different temperature conditions. Experiments
were performed in duplicate.
Figure 6 . Photosynthesis irradiance (PI) response curves
(measured at 30 °C) for the algal cultures at different temperature
treatments in (a) Phase II on day 27, A-35 °C, C-30 °C, F-20 °C, and
H-35 °C, and (b) Phase III on day 43, AB-ExSP, CD and EF-AvSP and
GH-CtSP.
Figure 7 . Experiment results of biomass productivity in
comparison to the productivity model simulation. The productivity model
parameter set, representative of the PI database at 30 °C, is [α,
Ek, R0] = [0.061 fixed C/photon, 240
µE/m2-s, 0.1 µmolC/mgChl.a-min].
Figure 1