Conclusions
We have provided here a detailed study of temperature impacts onArthrospira platensis biomass production in
semi-continuous operation. This temperature study of Arthrospira
platensis in photobioreactor cultivations demonstrates that
temperatures in the 20 - 35 °C range are favorable for achieving
consistent productivities, though long term exposure to 35 °C caused
some modest changes in productivity and more obvious changes in
pigmentation. Exposure to simulated conditions for summer temperature
profiles for Southwest Florida shows some issues for the most extreme
conditions but a general tolerance for the short term, mid-day exposures
to higher temperatures. The response of the cultures to abrupt changes
in temperature is immediate for biomass production and quantitatively
consistent with the temperature dependence observed for
Pmax in smaller scale photosynthetic response
experiments. Pigment variations with abrupt changes in temperature
occurrs on a time scale that was essentially the same as that expected
for turnover of the cell population under semi-continuous operation. No
other acclimation effects were identified. These results all involve
annual average irradiance conditions. Extension of this study to higher
irradiance conditions in the summer may cause additional issues in
combination with extreme temperature exposures, high or low.
Productivity modeling based on photosynthetic parameters derived from
periodic sampling of the cultures provides excellent agreement with
experiment and consistency with the performance of large scale outdoor
PBR cultivations.