Synechocystis sp. PCC6803 exhibited a high degree of variation in biomass and lipid production rates in response to temperature changes in a photobioreactor. Compared with an optimal temperature of 30-33. °C, a higher temperature of 44. °C and lower temperatures of 22. °C and 18. °C severely inhibited the specific growth rate (up to a 66% decrease), biomass production rate (up to a 71% decrease), nutrient utilization rates (up to a 77% decrease), and lipid production rate (up to a 80% decrease). Temperature stress triggered changes in the relative percentage of individual fatty acids (mainly for C16:0 and C18:3), and degree of unsaturation significantly changed: 0.87 at 30. °C, 0.62 at 44. °C, and 1.29 at 18. °C. Although PCC6803 survived temperature stress and maintained its predominate position in the culture, it could not fully recover from long-term temperature stress. Thus, avoiding prolonged exposure to extreme temperature is crucial for using PCC6803 as feedstock for biofuel production.
Bibliographical noteFunding Information:
We gratefully thank British Petroleum (BP) , Science Foundation Arizona (SFAz) , Arizona State University , and US Department of Energy (US DoE) through ARPA-E funding for providing financial support. We acknowledge the scientific help by Wim F.J. Vermaas, Robert Roberson, and other colleagues in the School of Life Sciences, Arizona State University for providing inoculum and light microscopy. We appreciate critical help by Mark Holl, Rhett Martineau, Jeff Houkal, and Juan Vela at Center for Biosignatures Discovery and Automation (formerly known as Center for Ecogenomics), the Biodesign Institute, Arizona State University for their technical help in maintaining bench-top photobioreactor operations.
- Biomass production
- Fatty acids
- Synechocystis sp. PCC6803