0.35-liter PBR cultivation conditions
For 0.35 L PBR operation, the reactors were inoculated with theArthrospira strain grown at 30 °C to a concentration of 0.5 gDW
L-1. The pH value was maintained between 9.2-9.8 with
an aeration rate of 80 mL min-1 supplying 0.75 %
CO2 during the light phase and 0.20 %
CO2 in the dark phase for cultures grown at 30 °C and 35
°C. The cultures grown at 20 ° C were supplied with 0.38 %
CO2 during the light phase, and 0.2 %
CO2 in the night phase. The light regime for the
cultures was a 12 h light:12 h dark cycle with light intensity of 230
μmol m-2 s-1 from one side of the
PBRs using fluorescent lamps (Plusrite). This irradiance level was
chosen to model annual average conditions for typical vertical PBR
arrays deployed in Fort Myers, Florida. For CO2 aeration
and mixing of the cultures, a custom designed porous air diffuser (0.5
mm diameter) was used in order to generate mm-size gas bubbles for
aeration at a constant flow rate of 80 mL min-1.