Assessment of photosynthesis regulation in mixotrophically cultured microalga <i>Chlorella sorokiniana</i> [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Energy Efficiency and Renewable Energy, 2016.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 30-38 : digital, PDF file
- Additional Creators:
- National Renewable Energy Laboratory (U.S.), United States. Department of Energy. Office of Energy Efficiency and Renewable Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Mixotrophic growth of microalgae offers great potential as an efficient strategy for biofuel production. In this study, photosynthetic regulation of mixotrophically cultured Chlorella sorokiniana cells was systematically evaluated. Mixotrophic cells in the exponential growth phase showed the highest photosynthetic activity, where maximum photosynthetic O2 evolution was approximately 3- and 4-fold higher than cells in the same phase grown photoautotrophically in 1% CO2 (in air) and air, respectively. Additionally, characteristic chlorophyll fluorescence parameters demonstrated that no limitation in electron transport downstream of PSII was detected in mixotrophic cells. Up-regulation of photosynthetic activity was associated with high total ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylase activity and expression level of phosphoribulokinase (PRK). After 3 days, photosynthetic O2 evolution of mixotrophic cells that went to the stationary phase, was strongly reduced, with reduced photochemical efficiency and reorganization of the PSII complex. Simultaneously, enzymatic activity for Rubisco carboxylase and mRNA levels of Rubisco and PRK diminished. Importantly, there was almost no non-photochemical quenching for mixotrophic cells, whether grown in log or stationary phase. A decline in the quantum efficiency of PSII and an oxidized plastoquinone pool (PQ pool) was observed under N-depleted conditions during mixotrophic growth. Finally, these results demonstrate that photosynthesis is regulated differently in mixotrophically cultured C. sorokiniana cells than in cells grown under photoautotrophic conditions, with a particularly strong impact by nitrogen levels in the cells.
- Report Numbers:
- E 1.99:nrel/ja--5100-66919
- Other Subject(s):
- Published through SciTech Connect.
Algal Research 19 ISSN 2211-9264 AM
Tingting Li; Helmut Kirchhoff; Mahmoud Gargouri; Jie Feng; Asaph B. Cousins; Philip T. Pienkos; David R. Gang; Shulin Chen.
- Funding Information:
View MARC record | catkey: 23499377