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 were 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 showed 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 was 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
occurred on a time scale that was essentially the same as that expected
for turnover of the cell population under semi-continuous operation.
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. Productivity modeling based on photosynthetic parameters
derived from periodic sampling of the cultures provided excellent
agreement with experiment and consistency with the performance of large
scale outdoor PBR cultivations.