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Bioenergetic changes in the microalgal photosynthetic apparatus by extremely high CO 2 concentrations induce an intense biomass production
Author(s) -
Papazi Aikaterini,
Makridis Pavlos,
Divanach Pascal,
Kotzabasis Kiriakos
Publication year - 2008
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2007.01015.x
Subject(s) - photosynthesis , biomass (ecology) , bioenergetics , chemistry , environmental chemistry , production (economics) , biology , botany , agronomy , biochemistry , macroeconomics , economics , mitochondrion
Unicellular green alga Chlorella minutissima , grown under extreme carbon dioxide concentrations (0.036–100%), natural temperature and light intensities (Mediterranean conditions), strongly increase the microalgal biomass through photochemical and non‐photochemical changes in the photosynthetic apparatus. Especially, CO 2 concentrations up to 10% enhance the density of active reaction centers (RC/CS o ), decrease the antenna size per active reaction center (ABS/RC), decrease the dissipation energy (DI o /RC) and enhance the quantum yield of primary photochemistry (F v /F m ). Higher CO 2 concentrations (20–25%) combine the above‐mentioned photochemical changes with enhanced non‐photochemical quenching of surplus energy, which leads to an enhanced steady‐state fraction of ‘open’ (oxidized) PSII reaction centers (q p ), and minimize the excitation pressure of PSII (1 − q p ) under very high light intensities (approximately 1700 μmol m −2 s − 1 maximal value), avoiding the photoinhibition and leading to an enormous biomass production (approximately 2500%). In conclusion, these extreme CO 2 concentrations – about 1000 times higher than the ambient one – can be easily metabolized from the unicellular green alga to biomass and can be used, on a local scale at least, for the future development of microalgal photobioreactors for the mitigation of the factory‐produced carbon dioxide.